Roohollah R. Sharifi, MD, FACS

• Professor of Urology and Surgery, University of Illinois at Chicago College of Medicine
• Section Chief of Urology, Jesse Brown Veterans Administration Hospital, Chicago, Illinois

Multiple pathways appear to be involved in maintaining high pulmonary vascular tone before birth prehypertension medication lisinopril 10 mg buy. Pulmonary vasoconstrictors in the normal fetus include low oxygen tension phase 4 arrhythmia discount 5 mg lisinopril visa, endothelin-1 pulse pressure change during exercise discount lisinopril 10 mg with amex, leukotrienes heart attack jack johnny b bad purchase genuine lisinopril, and Rho kinase blood pressure very high cost of lisinopril. At birth, a rapid and dramatic decrease in pulmonary vascular resistance redirects half of the combined ventricular output to the lung, leading to an 8- to 10-fold increase in pulmonary blood flow. Increased pulmonary blood flow increases pulmonary venous return and left atrial pressure, promoting functional closure of the one-way valve of the foramen ovale. Systemic vascular resistance increases at birth, at least in part because of removal of the low-resistance vascular bed of the placenta. The largest drop in pulmonary vascular resistance occurs shortly after birth, although resistance continues to drop over the first several months of life until it reaches the low levels normally found in the adult circulation. In the first several hours of life, the ductus arteriosus functionally closes, largely in response to the increased oxygen tension of the newborn. This effectively separates the pulmonary and systemic circulations and establishes the normal postnatal circulatory pattern. The most critical signals for these transitional changes in the pulmonary vasculature are mechanical distention of the lung, a decrease in carbon dioxide tension, and an increase in oxygen tension in the lungs. Cyclooxygenase is the rate-limiting enzyme that generates prostacyclin from arachidonic acid. Although both cyclooxygenase-1 and cyclooxygenase-2 are found in the lung, cyclooxygenase-1 in particular is upregulated during late gestation (Brannon et al, 1998). This upregulation leads to increased prostacyclin production in late gestation and early postnatal life (Brannon et al, 1994; Leffler et al, 1984). Subsequently, it was recognized that these physiologic patterns may complicate the clinical course of neonates with diverse causes of hypoxemic respiratory failure. For example, neonates with meconium aspiration often have clinical evidence of altered vasoreactivity, but excessive muscularization is often found at autopsy. Neonates with congenital diaphragmatic hernia are primarily classified as having vascular hypoplasia, yet lung histology of fatal cases typically shows marked muscularization of pulmonary arteries, and clinically, these patients can respond to vasodilator therapy. However, the exact intrauterine events that alter pulmonary vascular reactivity and structure remain poorly understood. In experimental models, surgical ductal constriction or ligation performed in fetal lambs produces very rapid antenatal remodeling of the pulmonary vasculature. The physiologic and anatomic findings in these lambs after birth are similar to those observed in human infants, including increased fetal pulmonary artery pressure, pulmonary vascular remodeling, and profound hypoxemia after birth (Wild et al, 1989). It is not yet clear whether genetic factors increase susceptibility for neonatal pulmonary hypertension. In addition, production of the vasoconstrictor arachidonic acid metabolite, thromboxane, plays a role in pulmonary hypertension produced by chronic hypoxia (Fike et al, 2005). In addition, endothelin may affect vascular tone by increasing production of reactive oxygen species such as superoxide and hydrogen peroxide, which also act as vasoconstrictors (Wedgwood et al, 2001). Affected infants typically present shortly after birth with cyanosis and respiratory distress refractory to all known therapies including extracorporeal support, although later presentations (at several weeks or months of life) are increasingly recognized. Characteristic findings include simplification of lung architecture, widened and poorly developed cellular septa with a paucity of capillaries, and strikingly muscularized small arterioles accompanied by pulmonary veins within the same connective tissue sheath. Approximately 10% of alveolar capillary dysplasia cases have been reported to have a familial association, indicating a potential genetic component. Infants with prolonged, severe pulmonary hypertension out of proportion to the degree of lung disease may therefore benefit from a lung biopsy and/or targeted genetic evaluations to determine the etiology of their respiratory failure. In preterm infants, there is increasing recognition that chronic lung disease may be associated with significant pulmonary hypertension. Moreover, severe or prolonged pulmonary hypertension increases the risk of late morbidity and death (Khemani et al, 2007). In infants with evidence for significant pulmonary hypertension by echocardiogram, cardiac catheterization will allow for more accurate quantification of the severity of disease, as well as allow for vasoreactivity testing (Mourani et al, 2008). In the presence of right-to-left shunting across the patent ductus arteriosus, "differential cyanosis" is often present, which is difficult to observe by physical exam but may be detected by a gradient in the PaO2 and/or oxygen saturation between the right radial artery and descending aorta sites. Because the left subclavian artery may have either a preductal or postductal origin from the aorta, it is best to apply the oximeter probe to one of the feet for postductal pulse oximetry monitoring. It is also important to remember that a similar pattern of postductal desaturation may be observed in ductus-dependent cardiac diseases, including hypoplastic left heart syndrome, coarctation of the aorta, and interrupted aortic arch. In this setting, hypoxemia is related to the amount of pulmonary arterial blood perfusing the nonaerated lung regions. Therefore, these clinical findings can only suggest, and not confirm, the diagnosis. In general, the degree of hypoxemia is disproportionate to the severity of radiographic lung disease. Laboratory findings may include hypoglycemia, hypocalcemia, polycythemia, or thrombocytopenia. The initial echocardiographic evaluation rules out structural heart disease causing hypoxemia or ductal shunting. Echocardiographic signs such as increased right ventricular systolic time intervals and septal flattening are suggestive, but less definitive in making a diagnosis. High pulmonary venous pressure due to left ventricular dysfunction will elevate pulmonary arterial pressure, causing right-to-left shunting with little vasoconstriction. When severe left ventricular dysfunction accompanies pulmonary hypertension, pulmonary vasodilation alone may be ineffective in improving oxygenation and must be accompanied by targeted therapies to increase cardiac performance and decrease left ventricular afterload. Thus, careful echocardiographic assessment provides invaluable information about the underlying pathophysiology and will help guide the course of treatment. Mechanical ventilation is almost always required to improve oxygenation, to achieve normal lung volumes, and to avoid the adverse effects of high or low lung volumes on pulmonary vascular resistance. The goal of mechanical ventilation should be to optimize lung volumes, and care should be taken to avoid settings that may induce ventilator-induced lung injury, which can lead to inflammatory changes, pulmonary edema, and decreased lung compliance. The use of surfactant therapy to recruit the lung remains variable between centers (Fliman et al, 2006). A multicenter trial showed benefit in infants with parenchymal lung diseases such as meconium aspiration syndrome and sepsis, and also demonstrated that the benefit was greatest for infants with relatively mild disease (Lotze et al, 1998). Therefore, the use of surfactant should only be considered for infants with parenchymal lung disease. However, variability exists between centers regarding the use of hyperventilation to achieve alkalosis in order to improve oxygenation. The pulmonary vascular response to alkalosis is transient, and prolonged alkalosis may paradoxically worsen pulmonary vascular tone, reactivity, and permeability edema (Laffey et al, 2000). Further, alkalosis produces cerebral constriction, reduces cerebral blood flow and oxygen delivery to the brain, and may be associated with worse neurodevelopmental outcomes (Ferrara et al, 1984). Similarly, there is currently no evidence to suggest that the use of sodium bicarbonate infusions to induce alkalosis provides any short-term or long-term benefit (Walsh-Sukys et al, 2000). Systemic hemodynamics should be optimized with volume and cardiotonic therapy (dobutamine, dopamine, and milrinone), to enhance cardiac output and systemic O2 transport. Systemic hypotension may worsen rightto-left shunting, impair oxygen delivery, and worsen gas exchange in patients with parenchymal lung disease. However, the goal is more complex than simply increasing blood pressure, and careful attention should also be paid to right and left ventricular function. For instance, the level of systemic arterial pressure is the major component of afterload for the left ventricle, and marked increases in systemic pressure have the potential to worsen left ventricular dysfunction. Some clinicians advocate increasing systemic blood pressure to prevent right-to-left shunting across the ductus arteriosus. Although this strategy may improve oxygenation, if it is not accompanied by a reduction in pulmonary vascular resistance, the right ventricle will also be presented with substantial increases in afterload. Because the right ventricle of the fetus and young neonate exhibits a high degree of sensitivity to afterload (Reller et al, 1987), this approach should be used with caution and accompanied by careful longitudinal assessment of biventricular function. This important observation may indicate that the underlying disease, antenatal factors, and/or early therapeutic approaches are associated with early neurological injury. In contrast, intravenous dilators such as prostacyclin, tolazoline, and sodium nitroprusside may produce nonselective effects on the systemic circulation, leading to hypotension as well as increased right-to-left shunting and impaired oxygenation. These studies also showed that doses of 5 to 20 ppm were effective, and that increasing the dose beyond 20 ppm in nonresponders did not improve outcomes (Neonatal Inhaled Nitric Oxide Study Group, 1997). The reasons for an inadequate response are diverse and require the clinician to carefully analyze the relative roles of parenchymal lung disease, pulmonary vascular disease, and cardiac dysfunction for each infant. In particular, infants with severe left ventricular dysfunction are likely to have pulmonary venous hypertension and are unlikely to respond to pulmonary vasodilation unless there is also optimization of cardiac performance. High concentrations of oxygen may be toxic to the developing lung through formation of reactive oxygen species, such as superoxide anions (Lakshminrusimha et al, 2006a). Both are potent oxidants with the potential to produce vasoconstriction, cytotoxicity, and damage to surfactant proteins and lipids. More recent findings from a multicenter, dose-range study of intravenous sildenafil for infants with severe pulmonary hypertension indicate that the drug was generally well tolerated, with improvements in oxygenation noted in the cohorts that received higher infusion doses (Steinhorn et al, 2009). It is interesting to note that systemic administration of sildenafil improved oxygenation, but had little effect on systemic blood pressure. Prostacyclin is a second central vasodilator that is upregulated after birth, primarily in response to ventilation of the lung. Superoxide dismutase scavenges and dismutates the superoxide radical to hydrogen peroxide, which is subsequently converted to water by catalase and glutathione peroxidase. It is associated with a diverse set of cardiopulmonary conditions, and its pathophysiologic mechanisms are characterized by vascular dysfunction, injury, and remodeling that occurs before and after birth. Current research is focused on developing a better understanding of cellular responses in the remodeled vasculature that will likely elucidate additional signaling pathways and lead to new therapeutic strategies. More work is needed to further improve the survival and neurodevelopmental outcomes of sick newborns with pulmonary hypertension, especially in patients with lung hypoplasia and advanced structural vascular disease. Vernon and Mark Lewin Echocardiography is the application of ultrasound to the evaluation of the cardiovascular system. Over the past several decades, echocardiography has become the gold standard for the determination of congenital and acquired cardiac malformations. Echocardiography provides reliable and reproducible information on cardiovascular form and function. Detailed cardiac structures can be identified, with differentiation of abnormal from normal anatomy, using high-resolution two-dimensional echocardiography. Accurate measures of myocardial thickness and cavity dimensions can be obtained via M-mode echocardiography. Components of hemodynamics, such as blood flow velocity and spatial direction, can be used to derive pressure measurements by the use of Doppler echocardiography. Echocardiography is important not only in the diagnostic evaluation of congenital heart disease but also in the overall assessment of the cardiovascular system in disorders unique to the fetus and newborn infant. Physiologic data points can be measured in a serial manner, which can be of great value in managing the fetus or sick neonate as conditions are explored and responses to management strategies are gauged. This chapter reviews the basic principles of echocardiography and their applications in the prenatal and newborn setting. An ultrasound wavelength distance is the physical limit beyond which two structures in space cannot be distinguished. The velocity of sound in biologic tissue is a constant at approximately 1540 meters/ second. This is the most commonly applied modality of echocardiography and is used primarily for determination of anatomic structure. When ultrasound energy is transmitted into biologic tissue, the majority is absorbed; however, a small amount is reflected back to the transducer. Ultrasound scatter is greatest at the interfaces between biologic tissues of disparate densities. Hence, bone and air, when adjacent to soft tissues such as the heart, create poor acoustic windows for ultrasound transmission. Soft tissue and fluid are excellent media for ultrasound transmission and provide clear windows for cardiac imaging (Weyman, 1994). Low-frequency ultrasound energy penetrates tissue better than high-frequency ultrasound; however, higher-frequency ultrasound provides for greater spatial resolution of fine structures. This principle is dictated by a fundamental law of physics that defines the relation between ultrasound frequency and wavelength: velocity of sound in biologic tissue = ultrasound frequency × wavelength M-Mode the earliest form of echocardiographic imaging, M-mode echocardiography, displays fine detail of cardiac structure along a time line. A single thin plane of ultrasound energy is focused onto a targeted region of the heart. All structures within the targeted plane of insonation are then displayed in real time as they change during various portions of the cardiac cycle. M-mode echocardiography is commonly used for measurement of myocardial wall thickness and cavity dimensions and is useful in estimating ventricular cavity size for calculation of the ventricular shortening fraction-an estimate of ventricular function. The electrocardiographic tracing helps identify the timing of the cardiac cycle as systolic or diastolic. Measurement A demonstrates the left ventricle enddiastolic dimension, and measurement B, the left ventricle end-systolic measurement. The interventricular septum moves paradoxically (arrow) because of elevated right ventricular pressure. The normal range is 28% to 38%, which correlates with a ventricular volumetric ejection fraction ratio of 55% to 65%, suggesting normal ventricular function. It provides for only a single-plane assessment of ventricular contraction and is invalid in conditions in which there is wall motion abnormality. Doppler Application of the Doppler principle allows for determination of the velocity and direction of moving objects. Because blood and myocardial tissue both are in motion throughout the cardiac cycle, either can be assessed by Doppler echocardiography. In pulsed-wave Doppler echocardiography, transducer crystals alternately fire pulses of energy and then "listen" for reflected signal return. This mode allows for determination of spatial signal position but limits the ability to measure blood traveling at higher velocities.

As mentioned previously prehypertension que es 5 mg lisinopril buy with mastercard, inadequate head and neck venous return can result in cerebral edema and postoperative neurologic complications blood pressure of 120/80 cheap lisinopril 10 mg buy on line. In cases of bicaval cannulation blood pressure medication used to stop contractions lisinopril 10 mg buy low cost, cardiopulmonary bypass is usually begun with only superior vena caval return arteriovenous malformation purchase lisinopril 10 mg amex, and its adequacy is ascertained by noting the volume of venous return and the central venous pressure blood pressure chart systolic diastolic pulse purchase lisinopril online. If the central venous pressure remains high, the superior vena caval cannula is moved around until a near-zero central venous pressure is achieved. Retrograde Aortic Dissection Retrograde aortic dissection is indeed a catastrophic complication that may follow femoral or external iliac cannulation. A diseased artery, faulty cannulation technique, and trauma produced by a high-velocity perfusion jet are major factors that may cause a tear of the intima with medial separation. It is therefore essential to introduce an adequately sized, beveled, smooth cannula into a relatively normal vessel in an atraumatic manner. The most significant diagnostic feature is low flow with high arterial line pressure in the circuit. The arterial return into the false lumen is responsible for excessive pressure in the arterial line while the actual perfusion of the patient is inadequate. The femoral artery or the external iliac artery on the opposite side should then be cannulated if not involved; otherwise, the ascending aorta, the subclavian or axillary artery must be cannulated. Traumatic Disruption and Dissection of the Ascending Aorta Intraoperative traumatic dissection or disruption of the ascending aorta is a rare but dramatic complication of open-heart surgery. The areas of aortic cannulation, the proximal anastomosis of an aortocoronary saphenous vein graft, and an aortotomy done for exposure of the aortic valve are the usual sites prone to such a complication. Although faulty techniques always predispose a surgical procedure to complications, poor tissue quality and the presence of infection are the most common key precipitating factors in the development of aortic injury. The only preventive measure is awareness of the possibility of such complications and meticulous surgical technique in handling the tissues. There continues to be many modifications of the chemical composition of the cardioplegic solution, the optimal temperature (cold or warm), and the route of infusion (antegrade or retrograde). As the concepts of myocardial preservation and surgical approaches have evolved, improved cannulas and cardioplegia delivery systems have been introduced. Although any large-bore needle or cannula is satisfactory, those with a trocar introducer and a side arm for direct intraaortic pressure monitoring are most useful. Insufficient Infusion Pressure Distortion of, or insufficient pressure in, the aortic root may prevent adequate coaptation of the aortic valve leaflets, as will aortic valve insufficiency. The cardioplegic solution passes through the open valve and overdistends the left ventricle, which can cause direct myocardial injury. Digital pressure on the right ventricular outflow tract at the level of the aortic annulus may produce coaptation of the leaflets and prevent regurgitation of the cardioplegic solution. Excessive Infusion Pressure Excessive infusion pressure can traumatize the coronary arteries, resulting in ischemic myocardial injury. Accurate monitoring of the infusion pressure in the aortic root can be satisfactorily accomplished from the side arm of specially designed cannulas. Air Embolism Air embolism to the coronary arteries can cause serious myocardial injury. A bubble trap is now incorporated into cardioplegia administration systems to minimize this possibility. Impurities in the Cardioplegic Solution Impurities and particulate matter may be present in the cardioplegic solution and can occlude terminal coronary arteries, causing myocardial injury. Quality control in the preparation of the cardioplegic solution prevents such complications. Warm Cardioplegic Solution Between infusions, the cardioplegic solution remaining in the tubing warms up. The warm solution should be flushed out through either the free arm of the Y connecting tube or into the vent before infusion into the coronary system. Maintaining Uniform Cooling Uniform cooling of the myocardium by infusion of cold cardioplegic solution is an integral part of myocardial protection. At some institutions, temperature probes in various parts of the septum and ventricular wall are used to monitor myocardial temperature during the course of the surgery. We typically utilize moderate systemic hypothermia, insulating pads, and topical cooling on the right ventricular surface in order to ensure uniform cooling. Inadequate Protection of the Right Ventricle Despite all precautions to keep the heart cool, the anterior surface of the heart tends to rewarm because of the ambient air temperature and the heat radiated from the operating room lights. A gauze pad soaked with cold saline and ice placed over the heart provides additional protection for the right ventricle. Topical Hypothermia Placement of an insulating pad, a commercially available cooling "jacket," or a cold lap pad behind the heart can minimize rewarming of the heart by the warmer blood in the descending aorta during the cardioplegic arrest. B: Cannula advanced into the coronary artery causing obstruction at the bifurcation. This technique is equally useful in patients who have more than mild insufficiency of the aortic valve. Cannula Damage to Coronary Ostium Excessive pressure from the cannula against the coronary ostium can cause an intimal tear or late ostial stenosis. Size of the Cannula the cannula must be the correct size, and only a snug fit is necessary to prevent leakage. A cannula head that is too large or excessive pressure on the coronary ostium may not only interfere with satisfactory perfusion of the coronary system but can also traumatize the coronary ostium. Short Left Main Coronary Artery the cannula can also interfere with satisfactory infusion of cardioplegic solution if the left main coronary artery is short. A branching artery may have its origin very near the ostium of the left main artery and therefore be obstructed by the head of the cannula itself. A flexible, hand-held, soft-tipped cannula with a collar around the tip can provide satisfactory infusion of cardioplegic solution directly into the coronary arteries. The collar presses against the aortic wall and the coronary ostium to prevent spillage of cardioplegic solution into the aorta. The technique provides retrograde perfusion of segments of myocardium that may not be equally perfused by the antegrade route in patients with severe coronary artery disease. To ensure optimal myocardial protection, an integrated method of antegrade and retrograde cardioplegia delivery is used in most centers. Almost all retrograde cannulas are dual lumen to allow infusion of cardioplegic solution and monitoring of pressure in the coronary sinus. A balloon, manually inflatable or self-inflating, surrounds the distal body of the cannula, approximately 1 cm from the tip, proximal to the flow holes. Technique Through a stab incision in the center of a 4-0 Prolene purse-string suture in the mid-atrium, a special retroplegia cannula is introduced and directed into the coronary sinus. The pursestring suture ends are snugged through a tourniquet, which is then tied to the cannula. When difficulty is experienced in placing the retrograde cannula, it is often possible to elevate the decompressed P. Intraoperative transesophageal echocardiography can often be helpful in directing the cannula along the course of the coronary sinus and verifying the correct position of the cannula. This is particularly important when performing cardiac surgery through minimally invasive incisions. Perforation of the Coronary Sinus the stylet and cannula must be guided into the coronary sinus very gently and not be advanced if any resistance is encountered. The coronary sinus wall is very thin and can be perforated by the stylet or the cannula tip. A tear in the coronary sinus must be dealt with by closing the epicardium carefully over the tear with a fine Prolene suture. Alternatively, it is patched with a piece of autologous pericardium when the patient is on full cardiopulmonary bypass to prevent stenosis or occlusion of the coronary sinus. Monitoring Infusion Pressure the infusion pressure must be kept above 20 mm Hg and below 45 mm Hg in order to achieve effective myocardial perfusion and avoid edema and coronary sinus rupture. To accomplish this, the position of the cannula or the flow rate must be adjusted accordingly. Monitoring Temperature the perfusionist monitors the temperature of the cardioplegic solution as it leaves the delivery system. The temperature can also be monitored as the solution enters the coronary sinus through some specially designed retrograde cannulas. Cannulas with manually inflatable balloons are usually more effective in preventing backflow. Inadequate Infusion of Cardioplegic Solution into the Right Coronary Vein If the cannula is advanced too far into the coronary sinus, the inflated balloon may obstruct the right coronary veincoronary sinus junction, thereby preventing any direct infusion of cardioplegic solution into the distribution of the right coronary vein. Retrograde Cardioplegic Infusion by the Open Technique When bicaval cannulation has been performed and the right atrium is opened, cardioplegic solution can also be administered directly into the coronary sinus. The balloon of the cannula is kept within the ostium of the coronary sinus with a purse-string suture of 4-0 or 5-0 Prolene to prevent leakage of cardioplegic solution into the right atrium. The balloon is inflated snugly to prevent backflow and to secure it in the appropriate position. Injury to the Conduction Tissue the purse-string suture must be placed on the inside of the coronary sinus ostium to prevent injury to the conduction tissue. It is particularly useful when a dry field is desired for precise repair of intracardiac defects. Its relevance becomes important when left ventricular venting is necessary before repeat sternotomy (see Repeat Sternotomy section in Chapter 1). Technique the region of the left ventricular apex may be thin walled and covered by fat. The site chosen for insertion of the vent must be well away from the branches of the coronary arteries and free of loose myocardial fat. There can be bleeding from this ventricular site after removal of the vent catheter. A double-armed, 2-0 nonabsorbable suture is passed in a U-shaped fashion through a suitable site near the left ventricular apex buttressed with rectangular Teflon felt pledgets. The distance between the stitches on the Teflon felt should be equal to the diameter of the vent catheter. This opening in the left ventricular apex is then dilated with a hemostat so that the vent catheter can be introduced gently into the left ventricle. If any catheter side hole remains outside the heart, the vent will be ineffective. When the heart is beating, gravity siphonage of the vent is usually adequate to decompress the heart and/or remove trapped air bubbles. When the heart is fibrillating or motionless, particularly after the administration of cardioplegia, the vent should be connected to gentle suction with adequate negative pressure to decompress the heart. When the catheter is removed, the U-shaped stitch is tied down snugly and, if necessary, reinforced with a few simple sutures. Length of the Catheter When an excessive length of the catheter is introduced into the left ventricle, its tip may traverse the aortic valve and drain much of the pump flow. For this reason, some vents have a double lumen and the second lumen can be left open to air. Alternatively, and probably a safer technique, the vent tubing can be vented with a one-way valve. Tearing or Bleeding When there is a tear or excessive bleeding from the left ventricular apex, the heart is decompressed. Long strips of Teflon felt with nonabsorbable sutures are used to repair the tear, as in techniques for resection of a left ventricular aneurysm. This is probably most safely accomplished with the heart arrested with cardioplegia. Air in the Ventricular Cavity If suction is too great or the apical opening is too large, air may be sucked into the left ventricular cavity around the vent site. After clamping the aorta, through a stab wound in the center of a rectangular or oval purse-string suture on the right superior pulmonary vein, the vent catheter is introduced into the left atrium and through the mitral valve into the left ventricle. The purse-string suture is then passed through a narrow rubber tube and snugged down. Dissecting the Adventitia with the Suture the adventitia within the purse-string suture over the right superior pulmonary vein should be dissected free to prevent any obstruction to the smooth insertion of the vent catheter. Injury to the Phrenic Nerve When placing sutures on the right superior pulmonary vein, care should be taken to avoid the phrenic nerve, which runs on the parietal pericardium along the anterolateral aspect of the right superior pulmonary vein. Reinforcing the Suture When tissues are thin and friable, the purse-string suture should be reinforced with Teflon felt. Air Embolism Air embolism can be eliminated by cross-clamping the aorta or fibrillating the heart before placing the vent catheter. Vent Injury the catheter should be introduced gently and allowed to cross the mitral valve into the left ventricle without excessive force to prevent injury of the mitral valve or perforation of the left atrium or left ventricle. This complication is more likely when the heart becomes flaccid after infusion of cold cardioplegic solution. An unexplained pooling of blood in the pericardial cavity should herald the occurrence of such a catastrophe. The tear should be located and repaired with pledgeted sutures before continuing with the operation. Difficulty Introducing Vent into Left Atrium Sometimes the vent will not pass easily into the left atrium. In these cases, the vent can be positioned after the heart is opened by passing a right-angled clamp through an atrial septal defect or patent foramen ovale P. This technique is similar to that described earlier for the right superior pulmonary vein. It is rarely used because it is cumbersome and control of bleeding from the vent site can be difficult.

How frequently need vaginal smears be taken after hysterectomy for cervical intraepithelial neoplasia The management of the patient with abnormal vaginal cytology following hysterectomy blood pressure log chart pdf lisinopril 10 mg amex. The role of partial colpectomy in the management of persistent 822 Benign Gynaecological Disease 16 17 18 19 20 21 22 vaginal neoplasia after primary treatment blood pressure chart diastolic high cheap lisinopril online visa. Vaginal intraepithelial neoplasia: comparing clinical outcomes of treatment with intravaginal estrogen blood pressure high heart rate low lisinopril 10 mg order on line. High dose rate brachytherapy in the management of high grade intraepithelial neoplasia of the vagina blood pressure medication used for anxiety cheap lisinopril 5 mg buy. Adenocarcinoma of the vagina in adolescence: a report of seven cases including six clear cell carcinomas (so called mesonephromas) prehypertension birth control pills lisinopril 10 mg generic. An analysis of 346 cases of clear cell adenocarcinoma of the vagina and cervix with emphasis on recurrence and survival. Muco 24 25 26 27 28 29 30 purulent cervicitis: the ignored counterpart in women of urethritis in men. Follicular cervicitis: colposcopic appearances in association with Chlamydia trachomatis. Longterm effect of wedge resection on androgen production in a case of polycystic ovarian disease. The management of mature cystic teratomas in children and adolescents: a retrospective analysis. Comparison of laparoscopy versus laparotomy for the surgical treatment of ovarian dermoid cysts. Benign focal intracavitary lesions are present inone third of premenopausal women and in almost half of postmenopausal women with abnormal uterine bleeding. In premenopausal women, focal intracavitary lesions, including intracavitary fibroids and endometrial polyps, become more prevalent with advancing age [1]. This chapter discusses each of these conditions and considers their aetiology, pathogenesis, presenting symptoms, diagnosis and treatment with inclusion of new developments, particularly in the treatment of symptomatic fibroids. In addition, gene polymorphisms have been identified in the oestrogen receptor, with mutations of oestrogen receptor alpha [5]. Abnormal prostaglandin production also occurs and this could exacerbate both pelvic pain and heavy bleeding. However, adenomyosis is often diagnosed in women without bleeding or pain symptoms, leading Weiss et al. The condition is reportedly characteristic of the fifth decade of life, with 45 years being the commonest age of presentation. Diagnosis the diagnosis is made on histological examination of the uterus after hysterectomy but the preoperative diagnosis may be suggested on ultrasound examination. Typical ultrasound features of adenomyosis include an asymmetrical thickening of the myometrium or a globular uterus, myometrial cysts, myometrial echogenic islands, fanshaped shadowing, subendometrial echogenic lines and buds, translesional vascularity and an irregular or interrupted junctional zone [8,9]. According to Brosens Adenomyosis Definition Adenomyosis is defined as the presence of endometrial tissue, including endometrial glands and stroma, in the myometrium and is associated with smooth muscle proliferation in the inner myometrium [2]. Adenomyosis typically results in uterine enlargement and an irregular endomyometrial border or junctional zone. The histological definition of adenomyosis usually includes a depth of penetration between 2. Incidence the reported incidence of adenomyosis in hysterectomy specimens varies considerably, ranging from 9 to 62% [4]. This wide range is likely to reflect the varying diagnostic methodologies used by different pathologists. Reproduced with permission of the International Society of Ultrasound in Obstetrics and Gynaecology. Various medical and minor surgical techniques have been shown to be of some benefit in the short term. Antifibrinolytics, nonsteroidal antiinflammatory drugs, the oral contraceptive pill and progestins may be considered as firstline methods of treatment. Endometrial ablation is not used as a firstline treatment of adenomyosis as it fails to remove deeply infiltrating endometrial glands. It has been shown to improve menorrhagia and dysmenorrhoea in some women, and those with superficial disease have good results from this treatment option. Those with deeply infiltrating disease, however, tend to have persistent symptoms and, if conservative therapy fails, should be offered hysterectomy if fertility is not an issue [13]. It has been shown to be effective in the short term, but there is a high rate of symptom recurrence within 2 years of treatment [14]. Its true prevalence is unknown, but it has been reported in 9­62% of hysterectomy specimens. Endometrial polyps Definition Endometrial polyps are discrete outgrowths of the endometrium containing a variable amount of glandular tissue, stroma and blood vessels. Polyps may be pedunculated Benign Disease of the Uterus 825 or sessile, single or multiple. They are relatively insensitive to cyclical hormonal changes and thus are not shed at the time of menstruation. The incidence of cancer in asymptomatic women and in women with postmenopausal bleeding diagnosed with a polyp is 0. Epidemiology In symptomatic women the prevalence of polyps is reported as ranging between 6 and 32% [17]. In their study they did not find an association between the presence of polyps and abnormal bleeding. Diagnosis Both fluid instillation sonography and hysteroscopy have a comparable diagnostic accuracy in detecting focal intracavitary lesions [18]. On transvaginal ultrasound examination a polyp typically is a relatively hyperechogenic lesion with or without small and regular internal cysts. The interface between the endometrium and the lesion often appears as a bright echogenic edge. In a premenopausal woman with a spontaneous menstrual cycle, an echogenic polyp is more readily detected in the proliferative phase of the cycle, when the endometrium is more hypoechogenic (threelayer pattern). In women on hormonal therapy or who are postmenopausal, where timed examination is not feasible, instillation of fluid into the uterine cavity will create a negative contrast against which focal intracavitary lesions are easily visualized (fluid instillation sonography). Hysteroscopy enables direct visualization of the uterine cavity and is often considered the reference test. On hysteroscopy, polyps can be distinguished from pedunculated fibroids as they have fewer vessels over their surface. Endometrial polyps are frequently missed with blind endometrial sampling, including dilation and curettage. There is no place for blind sampling without imaging in modern gynaecology [21,22]. Treatment There is consensus that symptomatic women with endometrial polyps should undergo hysteroscopically guided removal under direct vision. In the vast majority this will result in cessation of the abnormal uterine bleeding [23]. The resection may be performed either under general anaesthesia or in an outpatient setting with or without local anaesthesia or sedation [24]. The most accurate tests for diagnosing polyps are fluid instillation sonography and hysteroscopy. There is no place for blind sampling in the diagnosis of focal intracavitary lesions. Uterine leiomyomata (fibroids) Definition Uterine leiomyomata or fibroids are the most common benign tumours of the female genital tract, arising from neoplastic transformation of single smooth muscle cells of the myometrium. They usually appear as wellcircumscribed firm tumours with a characteristic whitewhorled appearance on crosssection. Fibroids are paler than the surrounding myometrium and there is usually a very sharp line of demarcation between the tumour and the normal uterine muscle. Histologically, they are typically composed of varying proportions of spindled smooth muscle cells and fibroblasts. The vast majority of fibroids are found in the corpus (body) of the uterus, but they may also occur in the cervix, uterine ligaments and ovary. Incidence the incidence of fibroids increases with age: it has been reported to occur in 20­40% of women during reproductive life and in as many as 70% of uteri removed at the time of hysterectomy [7]. Unlike a fibroid, which consists of spindled cells arranged in fascicles with abundant eosinophilic cytoplasm and uniform nuclei, a leiomyosarcoma is hypercellular and consists of atypical smooth muscle cells with hyperchromatic enlarged nuclei and shows increased mitotic activity and tumour cell necrosis [29]. However, the pathogenesis of leiomyosarcomas remains unclear and no evidence exists to suggest that fibroids undergo neoplastic change. There are significant racial differences in the incidence of fibroids, with AfroCaribbean women having a twofold to ninefold greater risk. In addition, they tend to present at a younger age compared with Caucasian women and have multiple fibroids and higher uterine weights and are more prone to both anaemia and severe pelvic Benign Disease of the Uterus 827 pain [30,31]. Independent of body mass index, smoking appears to decrease the risk of fibroid development [33,34]. Clonality studies using the homozygosity of glucose 6phosphate dehydrogenase forms show that multiple tumours in the same uterus are derived from individual myometrial cells rather than occurring through a metastatic process. This, together with their high prevalence, suggests that initial development arises from a frequently occurring event, the nature of which is currently unknown. Growth of fibroids is partly dependent on the ovarian steroids that act through receptors present on both fibroid and myometrial cells. It is likely that the control of growth is due, in part, to alterations in apoptosis. Bcl2, an inhibitor of apoptosis, is significantly increased in cultured leiomyoma cells. Most commonly, these involve translocation within or deletion of chromosome 7, translocations of chromosomes 12 and 14, and occasionally structural aberrations of chromosome 6 [35]. These cytogenetic abnormalities are not observed in normal myometrial tissue and may not be present in all the fibroids in a single uterus [36]. Abnormalities in uterine blood vessels and angiogenic growth factors are also involved in the pathophysiology of uterine fibroids. The myomatous uterus has increased numbers of arterioles and venules and is also associated with venule ectasia or dilatation. It has been noted that there are no mature vessels running through uterine fibroids despite the fact that they have a welldeveloped blood supply. Control of growth More information is available on the control of uterine fibroid growth than on the aetiology of these benign tumours. Growth factors are of importance in controlling the growth of fibroids and their composition. Higher concentrations of the angiogenic fibroblast growth factor have been found in fibroids than in the surrounding myometrium. As fibroids have not been identified in prepubertal girls and usually shrink at the time of the menopause, it has long been assumed that these lesions are dependent on the presence of the sex steroids, oestrogen and progesterone. The steroid combines with the receptor, which is then translocated to the nucleus of the cell. Studies have identified that steroid receptors are present in higher concentrations in fibroids than in the surrounding myometrium and that the concentration of receptors is significantly affected by the administration of agents which alter circulating estradiol concentration. The number of progesterone receptors is greater in fibroids than in the surrounding myometrium. Symptoms associated with uterine fibroids It is estimated that only 20­50% of women with one or more fibroids will experience symptoms that are directly attributable to them. In the case of small fibroids, it is often the assumed that only those impinging on the uterine cavity cause symptoms. This may be a result of the presence of surface vessels on the fibroid and/or the resultant increased surface area of the uterine cavity. Symptoms associated with fibroids may be variable, ranging from mild to severe, causing distress and impinging significantly on healthrelated quality of life. Not all women will present with a menstrual problem, some experiencing symptoms related purely to the size of the fibroid. This may be a dragging sensation or feeling of pressure in the pelvis, abdominal swelling or urinary symptoms. The relationship between fibroids and fertility is discussed in Chapters 51 and 52. Diagnosis the uterus is often found to be enlarged and presents as a pelvic mass (often central and mobile) on both abdominal and vaginal examination. Menstrual upset: menorrhagia and/or dysmenorrhoea Abdominal discomfort Sensation of pelvic pressure or backache Abdominal distension Urinary frequency, difficulty in micturition, incomplete bladder emptying or incontinence Bowel problems such as constipation Reproductive dysfunction: difficulty in conceiving, pregnancy loss, postpartum haemorrhage Medical treatment Gonadotrophinreleasing hormone agonists be difficult to distinguish between an enlarged uterus and an ovarian mass and so further imaging is mandatory. Ultrasonography, especially transvaginal, is very useful as a firstline diagnostic test. The echogenicity is highly variable: it may be uniform hypoechogenic, isoechogenic or hyperechogenic as compared with the surrounding myometrium, or nonuniform due to mixed echogenicity, internal hyperechogenic spots or calcifications. On colour Doppler a fibroid typically has circumferential vascularization, and sometimes some internal vascularization. There are no pathognomonic features for a leiomyosarcoma on any imaging technique. A large (8 cm), solitary, ovalshaped, heterogeneous myometrial tumour, with strong and irregular vascularization, central necrosis/ degenerative cystic changes and absence of calcifications should raise the suspicion of a leiomyosarcoma. Medical treatments do not eradicate fibroids but are designed to provide symptomatic relief. These drugs lead to the downregulation of pituitary receptors that result initially in stimulation of gonadotrophin release, followed by gonadotrophin output reduction and consequent reduction in ovarian steroid production within 2­3 weeks of commencing treatment. Fibroid shrinkage occurs rapidly in the first 3 months but then tends to slow down with little further decline. In addition, they are associated with postmenopausal side effects consisting of hot flushing, vaginal dryness and, with prologed use, significant bone loss. Their administration results in amenorrhoea, which is associated with a significant increase in haemoglobin.

Another oddity of the case was that Miss Chester was at no less risk if she opted for conservative therapy arrhythmia zoloft buy generic lisinopril pills. The evidence was conflicting blood pressure 6030 cheap lisinopril 2.5 mg, but some experts thought that she was at greater risk of longterm disability if she did not undergo surgery heart attack coub discount 5 mg lisinopril with visa. As she was in significant pain preoperatively arteria3d unity best lisinopril 10 mg, she would need to persuade the court that she would have undergone surgery or recovered spontaneously to recover full compensation when her quantum was assessed blood pressure definition purchase lisinopril 10 mg without a prescription. The problem is more acute for obstetricians and gynaecologists than it is for other specialties for a number of different reasons. They are truly elective procedures, which the woman must be free to accept or reject on her own terms. In obstetrics, the reduction of maternal mortality and the marginalization of infant mortality have meant that the woman feels that she should be put in a more powerful position. There has been thrust upon them a dual role in which they are seen as the servants of the law as well as their patients. Until the Abortion Act 1967 was passed, the doctor who performed an abortion in most circumstances committed a professional offence as well as a crime and would be struck off on conviction. When Parliament decided that it should be lawful to perform an abortion when the doctor believed that continuation of the pregnancy would be more hazardous to the health of the mother or other Summary box 69. The predicament of the obstetrician who is asked to treat a woman for an unwanted pregnancy was made more complicated in 1990. The compromise agreed upon was that until the pregnancy has exceeded its twentyfourth week, abortion should be available on the existing criteria, which effectively meant abortion on demand, even where the fetus may be larger than those in the adjacent neonatal intensive care unit. Since women do not become pregnant before they ovulate, which on average is not before the fourteenth day of the cycle, this means that a doctor who believes in good faith that the social ground is satisfied may lawfully terminate a pregnancy until 26 weeks from the last menstrual period. I stress that this is untested in court and the conventional view within medicine is that the limit has been set at 24 weeks; however, to sustain that view the court would have to say that the maturity of the pregnancy referred to the time since ovulation. The doctor was given the power to decide in consultation with the patient when it would be appropriate to perform an abortion. If that were right, it would be lawful at any point prior to delivery to abort a fetus who, on the balance of probabilities, would be born healthy. Parliament did not consider such questions as whether the child had to be abnormal at birth or destined to remain handicapped permanently. The intervening years have not been kind to a compromise based upon deference to the judgement of an individual clinician. With the rise of personal autonomy and the decline of medical authority, there is little role for a doctor to decide what is best for a patient and there is much less of a role for a doctor to tell a patient what they must and must not do. If a medical service is available, the assumption is that the doctor must provide it if the patient demands it and it is clinically appropriate. Something of a crunch point was reached in 2004 when a curate of the Church of England recognized in the statistics issued by the Department of Health that a pregnancy had been terminated at 26 weeks where the indication given was a cleft palate. If the lesion was a part of a broader syndrome, that was not apparent in the information published by the Department of Health. The police decided not to investigate further and an application was made for judicial review of that decision. The police agreed to reconsider matters and did investigate with a view to prosecution. Eventually they decided that the evidence available did not enable them to conclude that a prosecution would have a better than 50% chance of persuading a jury that the doctors did not have the bona fide belief that the circumstances of the Act were satisfied. The first is whether the compromise decided by Parliament was far more liberal than can be defended in view of intervening medical developments. Where advances in ultrasound have made it possible to visualize the unborn child more clearly than ever before, the difficulty in defending a decision to terminate on grounds of cleft lip and palate is harder to justify. The autonomy that the law accords the pregnant woman is based on the recognition that the unborn child is part of her body: this is challenged by the ability to visualize the fetus and watch it moving on ultrasound films that the mother carries on her mobile phone and to interact with it by performing medical procedures for its benefit. Nor does it help that advances in neonatology have brought the age of viability down still further, so that the fetus who is being killed is more often capable of being born alive and of surviving than ever before, often more mature than babies being treated in the critical care unit. This is something about which obstetricians may provide expert advice to the legislature but must remain essentially neutral. I wonder if we will not go further in the future: sometimes the assessment of longterm handicap might be enhanced by a multidisciplinary assessment involving specialists in neurological disability, physiotherapists, speech therapists or occupational therapists. The effect of a given physical lesion will vary greatly from case to case, depending on the personality of the victim and the resources available, as well as the severity of the lesion. The difficulty is that it is hard to see how such an assessment can be organized swiftly enough when the pregnancy is advancing. Few think it appropriate to provide women with an unqualified right to demand the destruction of a normal thirdtrimester fetus. Although doctors were placed in the front line, it is increasingly hard to understand what role society allots to them or how it expects them to perform this task. In few other areas of medicine are doctors asked to legislate between conflicting interests in this fashion; and where they have been granted a broad margin of discretion hitherto, as in endoflife decisions, that flexibility is being curtailed. In these circumstances the individual clinician needs to be aware of the conflicting obligations which are imposed by the law and the demands of patients. My own advice now is that, so far as possible, obstetricians should ensure that they have written objective advice from appropriate specialists on which to base their decisions. The Court ducked the question then and was forced to determine it in 1989 when a radiologist was sued in respect of his failure to recognize spina bifida [10]. In the meantime, obstetricians should be advised to cover themselves by seeking to buttress their decisions by obtaining the sort of written evidence that a court would demand. We could get almost any answer, from 20% ­ on the basis that a substantial risk is one that sensible people would take into account in ordering their affairs ­ to beyond all reasonable doubt, on the basis that a mature fetus should not be killed unless you are sure it will be handicapped. The latter is perhaps an extreme and unlikely view, but the court could easily demand the balance of probabilities. The standard of proof was reduced from the criminal to the civil standard: it was emphasized that the civil standard does not simply mean the balance of probabilities but the panels tend to take a confident approach to issues of fact. The National Clinical Assessment Service also grapples with the problem of the underperforming doctor, but its success rate for getting doctors back into practice once they have been identified as underperforming has not been good. It was also agreed by the profession that it should embark on some formal system of revalidation. It was agreed that revalidation needed to be something more, involving not only evidence of learning and reflection but also evidence of continuing ability, but the more ambitious programmes of revalidation fell on the stony ground of the unaffordable. Postgraduate training Another issue that is concerning for the future of the profession arises from the developments in professional training over the last 15 years. The introduction of the Calman Reforms and the Specialist Registrar Grade reduced the number of years of experience in training grades that a newly appointed consultant can be expected to have achieved by a similar proportion. The result is that the newly minted consultant acquires a fraction of the clinical hours of experience of their predecessor 30 years ago. In dealing with junior hospital doctors over the last 30 years, one feels that the profession has squandered a monastic tradition of devotion and apprenticeship. As a result, trainees cannot be entrusted, even under supervision, with the simplest procedures that recent predecessors could manage alone. The sense is that doctors are there to do a job within the hours for which they are paid, rather than to undertake a commitment to patients throughout the clinical pathway. The result is a decline in continuity of care and an attitude to handover that depends on written records rather than real communication to another doctor who will accept the same responsibility. Far more time is devoted to handover so that the proportion of junior time available for the management of the sick has fallen still further. Worst of all, the exposure of the junior doctor in each hour of experience that is gained is markedly reduced. One understands the need to protect patients and to ensure that the service they receive is safe and consistent, but the effects have been extreme. A newly appointed senior registrar of the 1970s would be likely to have performed more surgical procedures alone and to have experienced significant complications more frequently than the newly appointed consultant of today. The emphasis on using the hours of training for that very purpose is all to the good, in the sense that the juniors are well taught in a procedurespecific sense. But it is no way to acquire an understanding of the natural history of disease in humans, or the flexibility to recognize when things are going wrong. At the moment, the position is still being mitigated by the presence of senior consultants who benefited from the oldfashioned model of training. The Law and the Obstetrician and Gynaecologist 1005 Every year these consultants retire and are replaced by colleagues who simply do not have the same sort of training. To some extent the problems can be mitigated in elective surgery by increasing subspecialty and higher training in courses post appointment as consultant, but we are encountering a brave new world in more and more hospitals where there is no consultant who benefited from the oldfashioned sort of training. The idea that junior consultants are going to acquire the experience and training that they need in the course of their early consultant years overlooks the fact that they are not in a training grade and that increasingly there is noone there to train them if they do have the modesty to ask for help and guidance. For a time it looked as if the newly appointed young consultants would take on the attitudes of their seniors when appointed and accept the notion of 24hour responsibility necessary to provide continuity of care for those they regarded as their patients. The result was a massive bill that that threatened to cripple many Trusts and there had to be some firm negotiation. This change represented a turning point: the older doctors continue to provide the service their patients need despite the nominal fact that they are not being paid for it, but their attitudes already appear oldfashioned and are being replaced by a new respect for an appropriate work­life balance. A new generation has emerged, shaped in a fashion devised by the managers of the service rather than their clinical seniors. The conflict between the lack of training and the hostile environment the combination of this crisis in professional training and the lessforgiving professional environment in which doctors work means that the prospects for the individual doctor are ever gloomier. The basic premise of the reforms proposed by the Shipman Inquiry was that there is a plentiful supply of newly minted doctors available to replace those who are found not to have kept their professional skills up to date. This premise is profoundly mistaken and an unprincipled attempt to entice doctors to quit poorer countries ­ it cannot provide a sustainable solution. This explicitly involves an acceptance of the proposition that sometimes patients will make decisions which the doctor thinks are surprising, if not profoundly misconceived. The patient has an unfettered right to refuse surgery for good reason, bad reason or no reason. The doctor must ensure that the risks of inaction are spelled out as clearly as the risks of the intervention in question. It is as important to make detailed records of what is said to and by the patient as it is to make records of the clinical history that is elicited and the signs that are found. The patient who demands an unfair share of resources in the form of a caesarean section that the doctor thinks is not medically indicated is not in the same position as the woman who insists on home delivery against medical advice. Both are demanding a share of medical resources that seems to exceed the clinical indication in the eyes of the medical attendant, but the woman who demands an operation is demanding that her doctor does something that appears to be inappropriate. In other areas, the service operates on the premise that patients will not demand surgery which is not in their interests. We do have some experience of professionals being sued 1006 Miscellaneous Topics for unnecessary procedures in the context of dentistry. There is a longestablished line of cases in which patients have demanded extravagant, conservative restoration of teeth whose roots are unsuitable. The smile may be attractive at first but the life expectancy of the bridge is short. The conventional advice to a professional is that when a patient demands a procedure which appears to be contrary to their best interests, the professional should decline to perform it and offer to refer to someone else. If the autonomy of the patient is paramount and the playing field of knowledge of the implications of medical procedures becomes ever more level, it is difficult to understand how the status quo can be preserved indefinitely. Then, the concern of the obstetrician with the law was as it had been since 1980 when the House of Lords gave judgement in Jordan v Whitehouse [13] that the doctors involved would be sued by children suffering from cerebral palsy who sought to blame their disability on the doctor. Although the defence witness who gave evidence that the damage could not have been caused by the actions of which complaint was made, Professor Ronald Illingworth found his evidence rejected at trial. However the provisions for future payments are dominated by these cases and these are growing at double the amount paid by commissioners for obstetric services. It is also true that the number of children in the population suffering from cerebral palsy has remained roughly constant despite improvements in obstetrics and paediatrics that have transformed the rates of infant mortality and the prospects of survival of the child once delivered. This is probably due to the increased age of the parturient woman since the introduction of in vitro fertilization, and has been associated with increased rates of maternal obesity, diabetes and associated complications. It is also true that social expectations for a perfect result have made it difficult for us to defend such cases, even where the extremity of prematurity makes it clear that survival at all is astonishing. Claims handling was centralized in 2002, so that there is an additional level of insulation between the individual doctor and the damage. Risk management and clinical governance demand ever higher and more intolerant standards, but the massive financial impact of these claims is insulated from the services delivered in the individual Trust in that year. There was a period when a multimillion pound claim against the Trust would or could cause cashflow problems that sent the Chief Executive cap in hand to the regional office of the Department of Health. Maternal and newborn outcomes in planned home birth vs planned hospital births: a metaanalysis. Given the exponential rise in the numbers of scientific publications, doctors increasingly face the double challenge of keeping up with the latest information and choosing the best tests or treatments based on sound evidence from appropriately conducted research. Evidencebased guidelines, however, cannot compensate for poor clinical skills in eliciting a diagnosis or interpreting a test result or performing a procedure. Practical evidencebased medicine Any clinic consultation throws up a number of questions. Acquire: a hierarchical approach to literature searches, starting with known repositories of clinical practice guidelines and evidencebased reviews before moving onto primary research data. Appraise: all search contents should be subjected to a rigorous process of evaluation in the local context. For example, for effectiveness of interventions such as medical or surgical treatments or more complex interventions, the appropriate studies are randomized trials. Either cohort or case­control studies might be appropriate for investigating the aetiology of clinical conditions, while cohort studies are suitable for assessing prognosis.

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