Laxmi S. Mehta, MD, FACC

• Director, Women? Cardiovascular Health Clinic
• Assistant Professor, Clinical Internal Medicine
• The Ohio State University

Particular attention should be paid to positioning issues erectile dysfunction under 25 discount 100 mg zudena overnight delivery, such as severe scoliosis or orthopnea (see Chapter 41) erectile dysfunction drugs nhs purchase zudena 100 mg with visa. Yet erectile dysfunction drugs in ghana buy zudena overnight delivery, laboratory studies should be determined based on the results of the history and physical examination erectile dysfunction rates cheap zudena 100 mg online. Generally erectile dysfunction treatment with homeopathy zudena 100 mg on-line, the tests that a patient needs before ophthalmic procedures are the same tests a patient would require at a routine examination if surgery were not planned. Indications for laboratory studies and critical results are as follows: · Electrocardiogram: New chest pain, decreased exercise tolerance, palpitations, near-syncope, fatigue, or dyspnea; tachycardia, bradycardia, or irregular pulse on examination · Critical results: Signs of acute ischemia or injury, malignant arrhythmia, complete heart block, atrial fibrillation that is new, or heart rate more rapid than 100 beats/minute · Serum electrolytes: History of severe vomiting or diarrhea, poor oral intake, changes in diuretic management, or arrhythmia · Critical results: Sodium less than 120 mEq/L or greater than 158 mEq/L; potassium less than 2. For these procedures, evaluation is focused on patients with major clinical predictors of risk. These major predictors and the evaluation of the patient are reviewed in Chapters 38 and 39. Stage 3 of severe hypertension is defined as a systolic blood pressure of 180 mm Hg or more or a diastolic blood pressure of 110 mm Hg or more. Elective procedures in patients with sustained stage 3 hypertension should be delayed until after 2 weeks of antihypertensive therapy. If the patient cannot lie flat, or if there is intractable cough, a perioperative complication is more likely. Preoperative risk reduction strategies include cessation of cigarette smoking, treatment of airflow obstruction with bronchodilators or steroids, and administration of antibiotics for respiratory infections. For some patients, treatment with a mild stimulant such as caffeine can be helpful in keeping them awake and cooperative during a procedure. Discomfort and anxiety are associated with many of these blocks, and so are rare but severe complications. Supplementation with intravenous sedation and continuous patient monitoring are frequently preferred. Most patients meet recovery discharge criteria at the end of surgery, and can bypass a stay in the postanesthesia care unit. Arterial blood pressure, electrocardiogram, and oxygen saturation monitors are placed. An air blower is often placed with the outlet on the chest to eliminate carbon dioxide and oxygen buildup under the drapes and to prevent claustrophobia. This author omits midazolam and fentanyl in patients with limited cognitive reserve resulting from stroke or mild dementia. Hyaluronidase can also be important in preventing anesthetic-related damage to the extraocular muscles. Insulin therapy should be used, if needed, to maintain blood glucose at 150 to 250 mg/dL. The potential for autonomic neuropathy needs to be considered, especially when elevating the patient from the supine position. Patients undergoing long-term steroid therapy generally do not require "stress-dose" steroid treatment for ophthalmic surgery. The physician should be alert to the occasional patient who might require additional glucocorticoid perioperatively. Unexpected hypotension, fatigue, and nausea may be signs of a patient who needs additional steroid. Perioperative management of anticoagulants involves weighing the relative risks of thrombotic against possible hemorrhagic complications. In a study of more than 19,000 cataract procedures, the incidence of hemorrhagic and thrombotic complications was infrequent. Serious complications from arterial thromboembolic disease, such as atrial fibrillation or valvular heart disease, are much more common than complications from venous disease, such as deep vein thrombosis. The risk factors for thromboembolism, especially if and when the patient had a previous episode of thromboembolism. Serious hemorrhagic complications are most probable in orbital and oculoplastic surgery; of intermediate probability in vitreoretinal, glaucoma, and corneal transplant surgery; and least likely in cataract surgery. A consensus is developing that cataract surgery can be performed safely while maintaining patients receiving warfarin. For intermediate-risk procedures, such as some glaucoma surgeries, stopping warfarin intake for 4 days preoperatively is indicated. Modified van Lint block: the needle is placed 1 cm lateral to the orbital rim, and 2 to 4 mL of anesthetic is injected deep on the periosteum just lateral to the superolateral and inferolateral orbital rim. The disadvantages of this block include discomfort, proximity to the eye, and common postoperative ecchymoses. The needle is inserted perpendicular to the skin approximately 1 cm to the periosteum. Nadbath-Rehman block: A 12-mm, 25-gauge needle is inserted perpendicular to the skin between the mastoid process and the posterior border of the mandible. The needle is advanced its full length, and after careful aspiration, 3 mL of anesthetic is injected as the needle is withdrawn. The patient should be told to expect a lower facial droop for several hours postoperatively. The major disadvantage to this block is the proximity of the injection to important structures, such as the carotid artery and the glossopharyngeal nerve. If no bulging is noted at the superior nasal lid area, a second injection of 2 to 3 mL is administered inferonasally. Disadvantages of the technique include a longer onset time (9 to 12 minutes) and lower incidence of complete akinesia. A 2- to 3-mm spot of cautery can be made 5 mm from the limbus in the inferonasal or inferolateral quadrant. A 2-mm snip is made in the conjunctiva with blunt dissection through the fascia of Tenon. A blunt cannula is directed under fascia of Tenon posteriorly, but not beyond the equator of the globe, with injection of 1 to 3 mL of local anesthetic. The needle is placed at the junction of the inferior and lateral walls of the orbit just above the inferior orbital rim. The needle is advanced until it enters between the extraocular muscles; 2 to 3 mL of anesthetic solution is injected. Some intorsion on downgaze is expected because the superior oblique muscle is outside the muscle cone and may not be blocked. Retrobulbar hemorrhage is the most common complication of this block; proptosis and subconjunctival ecchymosis also are seen. If the pressure becomes elevated, a lateral canthotomy is performed to decompress the orbit. Bleeding outside the muscle cone is seen as subconjunctival ecchymosis without proptosis. The total dose of local anesthetic used is small, and even if the total dose is given intravenously, no systemic effects would be likely. Accidental intraarterial injection can give high brain levels via retrograde flow in the internal carotid artery. Central nervous system excitation and seizures can be seen, but are usually highly transient, as the local anesthetic redistributes out of the brain. These prolonged effects are thought to be due to injection into the optic nerve sheath, which is continuous with the subarachnoid space. Optic nerve damage and ocular perforation with retinal detachment and vitreous hemorrhage also have been reported. If the axial length of the globe is longer than 25 mm, the eye is larger, and the sclera is thinner, increasing the risk of ocular penetration. Topical anesthesia avoids the potential complications associated with retrobulbar and peribulbar injections. In addition, patients have the most rapid visual rehabilitation, with improved vision almost immediately after the procedure. Disadvantages of the technique include the potential for eye movement during surgery, increased patient anxiety, and discomfort from the microscope light. Approximately three more doses of tetracaine or lidocaine are applied every 5 minutes just before surgery. A nervous, hypersensitive patient may be a better candidate for another technique. Photophobic patients, those with small pupils, or the requirement of a large incision are other problems that may occur. In the past, regional anesthesia had an advantage of greatly reduced postoperative nausea and vomiting. Droperidol has been used frequently as an antiemetic, although late postoperative anxiety can occur in some individuals. A comparison of memory function in patients after general anesthesia or local anesthesia with sedation showed no advantage to either technique. These goals can be accomplished with inhaled volatile anesthesia, balanced opioid anesthesia, or intravenously administered anesthetics, with or without muscle relaxants. Sulfur hexafluoride is a poorly soluble gas used to prolong the resorption of intravitreal air bubbles. Nitrous oxide should be shut off for 15 minutes before placing the sulfur hexafluoride bubble and should be avoided for 7 to 10 days thereafter. This problem is potentially worse with a relatively newer drug, perfluoropropane (C3F8), because this drug can persist for weeks. In this case, nitrous oxide should be avoided for at least 1 month, or until the bubble is resorbed. If a patient presenting for nonophthalmic surgery has a history of a recent retinal procedure, it is critical to establish whether the patient has an intravitreal gas bubble before using nitrous oxide. Succinylcholine causes a tonic increase in eye muscle tone, which resolves in approximately 20 minutes. There is a more frequent incidence of strabismus in trisomy 21 or Down syndrome, cerebral palsy, and hydrocephalus. Patients with Marfan syndrome have a frequent incidence of subluxation or dislocation of the lens. Aniridia, the congenital absence of the iris, is associated with Wilms tumor and hypertension. Congenital glaucoma also occurs with Sturge-Weber syndrome and with seizures and angiomas of the mouth and larynx. Pediatric ophthalmic conditions associated with congenital syndromes are summarized in Table 84-1. Enucleation can be performed during regional anesthesia, but is usually performed during general anesthesia. Surgical treatment is indicated when there is inadequate response to conservative methods. Intramuscular ketamine sometimes can be a good choice; it can be used when intravenous access may be problematic. The most common eye surgery in children is for strabismus, or misalignment of the eyes. There is generally no severe postoperative pain, but nausea and vomiting are significant 50% to 80% of the time without treatment. Droperidol 5 to 75 g/kg seems to decrease nausea and vomiting significantly without undue delay of discharge. Intracapsular cataract extraction is performed in selected cases of lens subluxation, dislocation, or a lens containing a foreign body. Baerveldt and Ahmed devices are glaucoma drainage implants that shunt aqueous fluid out of the eye to drain under the conjunctiva of the orbit. Extracapsular Cataract Extraction Extracapsular cataract extraction refers to the removal of the lens, while leaving the posterior lens capsule and zonules intact. A rim of the anterior capsule also is preserved; this provides an excellent location for an intraocular lens implant. New techniques are bringing the use of the femtosecond laser for the initial steps of creating corneal incisions, capsulotomy, and fragmenting the lens. Penetrating Keratoplasty A corneal transplant is done to replace an optically poor, infected, or traumatized cornea. Lamellar Keratoplasty Instead of a full thickness corneal graft, a layer of the corneal donor is used. After elevation of the intraocular pressure, the size of the gap is decreased (B, C). Radial Keratotomy A series of incisions is made in the cornea in a spikelike manner to change the shape of the cornea to correct myopia. Many patients have diabetes or severe chronic hypertension, which can influence the conduct of anesthesia (see Chapter 39). Pterygium Excision A pterygium is an abnormal fold of membrane in the interpalpebral fissure. An excision is generally performed when the abnormal tissue impinges on the cornea, affecting vision, or for cosmetic improvement. This technique is used in some patients with retinal tumors and vascular malformations. Repair of Retinal Detachment Retinal reattachment involves localizing all tears and holes, creating chorioretinal adhesions, and scleral buckling with silicone belts around the globe to pull the sclera in to support the retina. Ptosis Repair Ptosis, or drooping of the upper eyelid, can be congenital (dystrophy of the levator muscle) or acquired from aging or trauma. Vitrectomy Vitrectomy is the surgical extraction of the contents of the vitreous chamber and their replacement with a physiologic solution. A posterior vitrectomy is indicated for the Blepharoplasty Blepharoplasty is plastic surgery of the eyelids to remove redundant tissue that is obstructing vision, or for improved appearance. If a patient emerges from a general anesthetic complaining of vision impairment, an emergency may exist because of the possibility of central retinal artery occlusion. When using a facemask, care must be taken to avoid applying undue pressure to the eye.

Hyperthermia that develops postoperatively may be just as hazardous as intraoperative hyperthermia erectile dysfunction causes treatment generic zudena 100 mg buy online. Blood Gas Management Temperature has a significant effect on the solubility of gases in solution erectile dysfunction wikihow purchase 100 mg zudena with mastercard. Specifically adderall xr impotence zudena 100 mg order overnight delivery, in blood gas analysis erectile dysfunction treatment caverject zudena 100 mg sale, the carbon dioxide concentration (and consequently the pH) is profoundly altered by changes in temperature erectile dysfunction when drugs don't work order zudena online pills. As temperature decreases, the partial pressure of arterial carbon dioxide (PacO2) decreases as carbon dioxide becomes more soluble in plasma. This question has been the basis for a decades-old debate: alpha-stat versus pH-stat blood gas management (Table 67-8). The dissociation of water depends on temperature; therefore, the pH value at which pN occurs varies with the temperature. Acid-base comparative physiologic studies of animals whose blood temperature varies. It is thought that protein buffering is largely responsible for maintaining this temperaturepH relationship. Specifically, the imidazole group of the amino acid histidine has a dissociation constant (pKa) value similar to that of blood. Therefore, if carbon dioxide stores are held constant during cooling, the ionization state (termed alpha) will remain constant. This may be important because the ionization state affects both the structure and the function of proteins. Chapter 67: Anesthesia for Cardiac Surgical Procedures 2041 structure and function of enzymes during hypothermia. Research suggests that when the alpha-stat strategy is used, cerebral autoregulation remains largely intact until deep hypothermic temperatures are reached. The term uncorrected is often confusing because it refers to the values that the blood gas machine typically reports without being programmed to correct the values to the actual temperature of the patient. With alpha-stat management, one would strive for normal temperature-uncorrected results, which would theoretically maintain intracellular electrochemical neutrality. The pH-stat strategy endeavors to maintain a constant pH despite changes in temperature. To counter the tendency of cooling blood to follow the neutrality of the water curve and become more alkalotic as temperature decreases, these animals increase their blood carbon dioxide content and maintain normal pH at hypothermic body temperatures. Carbon dioxide is a potent cerebral vasodilator; therefore, the increase in carbon dioxide content during pHstat management uncouples cerebral autoregulation; cerebral blood flow increases independent of cerebral metabolic demand. During bypass, decreasing blood temperature increases the solubility of carbon dioxide and, consequently, results in decreased PacO2 values. Therefore, the perfusionist must either decrease the "sweep speed" of the air-oxygen mixture or, less commonly, add carbon dioxide to the oxygenator ventilation system to increase the carbon dioxide content and maintain a PacO2 of 40 mm Hg (and normal pH) as the temperature of the blood decreases. In adult patients, several independent, prospective randomized trials have shown that using alpha-stat management during moderate hypothermia produces better neurologic outcomes than observed with pH-stat management. These studies showed that pH-stat management produced more homogeneous cooling, less oxygen consumption, and better cerebral metabolic recovery than did alpha-stat management. This response can produce tissue injury of varying degree in a variety of organ systems. Numerous clinical approaches have been shown to reduce the inflammatory response measurably in cardiac surgical patients. These approaches can be loosely grouped into three primary categories: modification of surgical and perfusion techniques, modification of circuit components, and pharmacologic strategies. The movement toward minimally invasive cardiac surgery is at least partly motivated by the goal of reducing inflammation in the patient. Rather, minimizing or eliminating aortic manipulation, particularly in patients with severe atherosclerosis, may independently reduce the incidence of stroke. No consensus exists regarding which arterial pump technology, roller pumps or centrifugal pumps, is less hemolytic. Warren and associates,223 in a review of 63 studies, concluded that leukocyte filtration may have some modest benefits, but definitive evidence of any improvement in inflammatory-mediated complications is insufficient. Corticosteroids have been used in cardiac surgery for decades for their immunosuppressive and antiinflammatory effects. The results of meta-analyses of small randomized clinical trials of methylprednisolone or dexamethasone have yielded conflicting results. In adults, this procedure is primarily used during surgical repair of the aorta, especially in cases of dissection or aneurysm involving the transverse arch. Deliberate hypothermia with systemic cooling is the only reliable method of neuroprotection during complete global ischemia. Pharmacologic approaches to neuroprotection, such as administering steroids to reduce inflammation or barbiturates or propofol to induce burst suppression, are used in some centers, although evidence to support their efficacy in the setting of complete global ischemia is scant. The best-established drug, aprotinin, was removed from the market in 2007 because of concerns about an increased risk of acute kidney failure after administration. When deciding what temperature is "adequate," one must give top priority to protecting the brain. Because no clinically feasible method for measuring brain temperature is available, surrogate temperatures must be used to estimate core temperature (see the earlier section on temperature). Consequently, when aggressive cooling is used, arterial blood temperature underestimates brain temperature. For an anticipated circulatory arrest period of 30 to 40 minutes, a temperature of 18° C to 20° C is probably adequate; however, slightly warmer temperatures may be acceptable if a shorter period of arrest is used or if cerebral perfusion is maintained. At a temperature of 18° C, the viscosity of blood with a hematocrit of 30% to 35% increases to three to four times its normal level. Cardiac surgical textbooks suggest that hemodilution is important in minimizing any microcirculatory disturbances that may occur because of increased blood viscosity. An initial period (5 to 10 minutes) of cold reperfusion may enhance cerebral protection by removing accumulated metabolic products from the cerebral capillary beds while maintaining a low cerebral metabolic rate of oxygen. In addition, hyperthermia, possibly secondary to a systemic inflammatory response, is common in the postoperative period and should be treated aggressively. In an effort to reduce the period of cerebral ischemia during circulatory arrest, selective cerebral perfusion techniques have been developed. Because of the proximity of the arterial cannula to the right radial artery, arterial blood pressure monitored in the right radial artery may be significantly higher than pressure monitored in the left radial or femoral artery. Consequently, right radial arterial pressure should not be used to control perfusion during cooling and rewarming. During delivery of selective antegrade cerebral perfusion, cold arterial blood from the extracorporeal circuit should be delivered to maintain the cerebral blood pressure between 30 and 60 mm Hg. The perfusion flow rates necessary to achieve this pressure vary depending on the site or sites of arterial cannulation. Direct cannulation of only the left common carotid artery requires the least flow, whereas cannulation of multiple head vessels or of the axillary artery (which perfuses the right common carotid, right internal thoracic artery, and right arm) requires higher flow rates. The application of vascular clamps to this major vessel acutely increases the afterload of the heart and produces global ischemia in all parts of the body distal to the clamp. Patients with compromised cardiac function or those undergoing a surgical procedure in which the duration of ischemia will be unacceptably long require some method of circulatory support. Surgical complications are not uncommon in these patients and include hypoxia, hypothermia, and exsanguination. A double-lumen endotracheal tube or bronchial blocker is often used to isolate the left lung from the right. After left thoracotomy and exposure of the aneurysm, ventilation of the left lung is discontinued. Patients with preexisting lung dysfunction or traumatic lung injury associated with aortic dissection may have difficulty maintaining oxygenation with a single lung. Because of the large surgical exposure required and the sometimes extended duration of the procedure, it is not unusual for the patient to become hypothermic. Furthermore, these procedures carry an elevated risk of blood loss and the consequent need for rapid replacement of fluids and blood products. In both circuits, the management goal is the same- to keep arterial blood pressure higher than 60 mm Hg both proximal and distal to the aortic cross-clamp throughout the procedure. The reservoir facilitates the addition of large volumes of fluid or blood products in the event of hemorrhage, hypovolemia, or both. Because the reservoir is removed from the circuit, these systems are considered closed. The removal of the reservoir and filters from the circuit has advantages and disadvantages. Additionally, because of the reduced anticoagulation regimen, blood stasis in the circuit should be avoided, and periods of low flow should be minimized. The newer generation of centrifugal pumps and hollow-fiber oxygenators perform acceptably well during these longterm applications and are becoming more commonly used in desperate situations. A, Patient cannulated through the internal jugular vein and femoral artery, with a traditional extracorporeal membrane oxygenation circuit. B, Patient cannulated through the femoral vein and femoral artery, with a simple cardiopulmonary support circuit. The septal branches supply the interventricular septum, as well as the bundle branches and the Purkinje system. As demand increases (with exercise or hemodynamic stress), the oxygen supply to the myocardium must also increase. Determinants of blood flow in normal coronary arteries include the pressure differential across the coronary bed. Because coronary stenosis causes vessels to dilate maximally distal to the stenosis, manipulating coronary perfusion pressure is an important means of controlling coronary blood flow (and preventing or treating myocardial ischemia). However, because the determinants of myocardial oxygen balance interact in a complex manner, altering any one of them can have multiple effects. For example, a rise in blood pressure increases coronary blood flow but also increases afterload, thereby elevating wall tension and oxygen demand. The duration of diastole is another important factor affecting oxygen supply to the myocardium because 70% to 80% of coronary arterial blood flow occurs during the diastolic phase of the cardiac cycle. During the systolic phase, cardiac contraction increases intraventricular cavitary pressure and coronary vascular resistance, thus impeding myocardial perfusion. The total time per minute spent in diastole is a function of the heart rate, but a nonlinear relationship exists between heart rate and the duration of diastole. This is a major reason for the use of -blockers as antiischemic drugs, both for longterm therapy and for preventing even small increases in heart rate during the perioperative period. The oxygen content of blood depends on hemoglobinbound oxygen and, to a lesser extent, dissolved oxygen. Although a high hemoglobin level gives the blood high oxygen-carrying capacity, the minimum level of hemoglobin necessary to avoid ischemia has not been well defined in clinical studies. A leftward shift of this curve caused by alkalosis, hypothermia, or low levels of 2,3-diphosphoglycerate decreases the release of oxygen. In patients undergoing myocardial revascularization, reductions in myocardial oxygen supply may occur because of hypotension, tachycardia, anemia, or coronary vasoconstriction, as well as increases in demand secondary to tachycardia or increased afterload. Although myocardial ischemia is certainly possible without any changes in systemic hemodynamics, vigilant monitoring for imbalances in myocardial oxygen supply versus demand, as well as monitoring for the development of ischemia, is necessary throughout the perioperative period. Frequently, the only premedication they receive is midazolam on the morning of the surgical procedure, to allay anxiety. Induction of anesthesia for coronary revascularization is often achieved by administering a benzodiazepine (typically midazolam) in combination with a narcotic, usually fentanyl, and a muscle relaxant. The goal is to avoid wide swings in hemodynamics with induction and with subsequent intubation. Typically, volatile agents are used throughout the prebypass, bypass, and postbypass periods to limit the total fentanyl dose to 10 to 15 g/kg. In addition, the volatile anesthetics have several cardioprotective effects, including triggering the preconditioning cascade and mitigating reperfusion injury. Use of -blockers, additional propofol, higher doses of a volatile anesthetic agent, or vasodilators may be warranted if this situation develops. Total time spent in diastole each minute plotted as a function of heart rate in beats per minute. The reduction in diastolic interval leads to diminished left ventricular blood flow as heart rate increases. Such patients may require vasopressor or inotropic pharmacologic support, or both. This strategy necessitates the use of agents in dosages that would not keep the patient sedated or render the patient unable to ventilate adequately for a prolonged period. Monitoring for patients scheduled to undergo coronary revascularization surgery has evolved since the 1960s, in an effort to detect intraoperative ischemia. This technology is commonly used throughout revascularization procedures to assess regional wall motion by qualitative inspection of radial shortening and wall thickening, and it is particularly useful after revascularization. Ventilation of the lungs is halted briefly during sawing of the sternum to avoid a pleural tear. The risks posed by redo sternotomy include perforation of the right ventricle, damage to existing vein grafts, and ventricular fibrillation from the transmission of electrocautery energy through preexisting sternal wires. Furthermore, surgical manipulation of previous vein grafts may result in embolization of atheroma and resultant ischemia. If a complication does occur during sternotomy or exposure of the heart and cannulation sites, emergency bypass may be established by cannulating a femoral artery and vein. The previously completed left internal mammary artery­to­left anterior descending coronary artery anastomosis is seen. Potential sources of bypass grafts include the right and left mammary arteries, the saphenous veins, and the radial arteries.

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Although these topical agents are important drugs that reduce bleeding and improve visualization during nasal and endoscopic procedures impotence at 80 zudena 100 mg buy on line, they sometimes produce cardiovascular toxicity erectile dysfunction and urologist zudena 100 mg purchase with amex. Consequently erectile dysfunction quick fix generic 100 mg zudena, cocaine would not be a first-choice vasoconstrictor in patients with coronary artery disease or hypertension or in patients taking monoamine oxidase inhibitors erectile dysfunction ugly wife effective zudena 100 mg. Phenylephrine is an -adrenergic agonist topical vasoconstrictor either used alone or in combination with lidocaine erectile dysfunction from steroids zudena 100 mg order on line. Because severe hypertension sometimes results following phenylephrine use, blood pressure monitoring is particularly important. Instances of unacceptable hypertension should be treated with direct vasodilators or -receptor antagonists; the use of -adrenergic and calcium channel blockers should be avoided because they may worsen cardiac output and produce pulmonary edema. If this tissue become hyperplasic, nasopharyngeal obstruction and a number of related problems can occur such that the adenoids merit surgical removal (adenoidectomy). Other indications for tonsillectomy include tonsillar hyperplasia, recurrent tonsillitis, and malignant disease. The presence of a fever or a productive cough may be grounds for postponement of the surgery or for postoperative care in setting of increased vigilance. Induction of anesthesia in adults usually entails administering intravenous drugs, whereas inhaled inductions are popular with children, followed by placement of an intravenous catheter and administration of glycopyrrolate. When a tonsillar or parapharyngeal abscess is present, the patient may have a compromised airway complicated by trismus and pharyngeal edema. Although awake abscess decompression by needle aspiration before the induction of anesthesia is sometimes done, awake fiberoptic intubation is the usual approach in this setting. At the end of the surgical procedure, the throat pack, if previously placed, should be removed, the oropharynx should then be suctioned, and an orogastric tube should be used to empty the stomach. Extubation is sometimes performed using deep anesthesia but more commonly is carried out when the patient has intact airway reflexes. Coughing on the tracheal tube on emergence may be attenuated by the administration of lidocaine, either Chapter 85: Anesthesia for Ear, Nose, and Throat Surgery 2537 given intravenously or placed down the tracheal tube with the cuff temporarily deflated. Posttonsillectomy hemorrhage is a dreaded surgical emergency, especially in children131-133 (see also Chapter 93). It usually occurs within the first 6 postoperative hours, but it can also occur several days later. When possible, the patient should receive appropriate intravenous fluids preoperatively (including blood products when necessary). The presence of hypovolemia may dictate a reduction in induction drug dosage or the use of etomidate. Because the stomach may contain a considerable amount of blood, a rapid-sequence induction with cricoid pressure is usually performed with a view to protect the airway from aspiration of gastric contents. Vigorous suctioning is also needed to remove the copious oropharyngeal blood likely to be found during laryngoscopy. Given the close proximity of major blood vessels and nerves, the orbit, and the brain, complications are possible, especially when the surgical landmarks are obscured by blood. Some major complications include orbital hematoma formation, blindness from orbital trauma or damage to the optic nerve, formation of cerebrospinal fluid leak, carotid or ethmoid artery invasion, entry into the cranial cavity, severe hemorrhage, and death. For example, although now largely replaced by endoscopic methods, the once common Caldwell-Luc procedure involves fenestration of the anterior wall of the maxillary sinus with surgical drainage of this sinus into the nose through an antrostomy. Hyperthyroid patients should be treated preoperatively to reduce the risk of thyroid storm (thyrotoxicosis). Thyrotoxic patients may experience sinus tachycardia, atrial fibrillation, myocardial ischemia, congestive heart failure, nervousness, tremulousness, insomnia, heat intolerance, weight loss, and other findings. Although deep extubation also reduces the incidence of bucking and straining, many clinicians avoid this technique wherever possible because of airway obstruction. Possible complications of thyroid and parathyroid surgery include hematoma formation (possibly resulting in airway impairment), vocal cord dysfunction from recurrent laryngeal nerve injury, pneumothorax, and other conditions. In patients with compressive goiters, postthyroidectomy tracheomalacia may occur following goiter excision. In postoperative patients who have undergone parathyroid and total thyroidectomy, serial calcium levels are taken to detect inadvertent hypocalcemia. Indications are varied and include conditions such as nasal polyposis, recurrent or chronic sinusitis, epistaxis control, tumor excision, orbital decompression. The most important goals are a blood-free surgical field, patient immobility, stable cardiorespiratory conditions, and gentle emergence from anesthesia. Controlled hypotension is sometimes used to improve surgical conditions; when this approach is used, intraoperative -adrenergic blockade is associated with better operating conditions than when vasodilation drugs are administered. Despite minimal arterial blood pressure differences, propofol-remifentanil intravenous anesthesia may provide better surgical conditions as compared with a traditional balanced technique. This system requires a special headset that may preclude the use of electroencephalographic (bispectral index) monitoring (see also Chapter 44). Although many simple procedures can be performed in well-selected individuals by using local anesthesia and intravenous sedation, more complex procedures, especially those requiring an operating microscope (for which immobility is essential), are usually best accomplished using general anesthesia with the presence of a secure airway. Regardless, in all such cases the anesthesiologist must consider issues such as the appropriate form of airway management, whether nitrous oxide is contraindicated, the possibility that postintubation muscle relaxants should be avoided to permit facial nerve monitoring, and the possible need for antiemetic prophylaxis. Most patients require a tracheal tube; the unkinkable, wirereinforced variety is commonly used to avoid airway trouble following head rotation. Nitrous oxide is avoided in middle ear procedures because it diffuses from blood to the middle ear, thereby increasing middle ear pressure and potentially distending any carefully placed tympanic membrane grafts. Many middle ear operations are performed to ameliorate hearing loss from infection or inflammation. The most frequent of these procedures, myringotomy with tube placement, is most commonly performed in children by using simple sevoflurane mask anesthesia, in conjunction with acetaminophen or (less commonly) fentanyl to treat postoperative pain. The procedure can usually be safely accomplished without establishing intravenous access. The use of a volatile anesthetic in combination with a remifentanil infusion helps provide mild hypotension (which reduces blood loss), as well as surgical immobility. Nitrous oxide can theoretically be used early in the procedure, but it must be avoided later on to avoid damaging possible "overlay" grafts to the tympanic membrane. Gentle emergence, often involving a remifentanil infusion, helps avoid coughing or "bucking" with the tracheal tube present, with possible displacement of the bone prosthesis. Not surprisingly, extubation of the trachea during deep anesthesia is sometimes performed. Common inner ear procedures include surgery to the cochlea, endolymphatic sac, and labyrinth. In cochlear implant surgery, mastoidectomy is performed to implant the signal coupler while the electrode array is implanted into the cochlea, a procedure often taking over 4 hours. Some surgeons also request a degree of hypotension as a means to reduce blood loss. Untreated chronic otitis media often leads to mastoiditis, tympanic membrane perforation, and damage the ossicular chain. Additionally, the formation of a cholesteatoma (an invasive growth of keratinizing squamous epithelium) may spread into the mastoid cavity, inner ear, and even to brain to cause additional damage. When antibiotic treatment fails, mastoidectomy (removing infected material, draining subperiosteal abscesses, and reestablishing middle ear ventilation) may be indicated. Because blood loss can be substantial, controlled hypotension is sometimes requested. The nerve identification and gentle emergence issues discussed earlier often apply as well. Nitrous oxide is often avoided, at least in the later stages, because of the tympanoplasty component of the procedure. Surgical procedures of the outer ear may be used to correct congenital and acquired malformations. Although these patients often present no special challenges, beware of patients whose malformation is part of Goldenhar syndrome or Treacher Collins syndrome because these patients frequently offer airway challenges. General anesthesia is typically employed, and postoperative pain can be substantial when a rib graft is used. Chapter 85: Anesthesia for Ear, Nose, and Throat Surgery Operating Room Fires Algorithm Fire prevention: · · · · Avoid using ignition sources1 in proximity to an oxidizer-enriched atmosphere2 Configure surgical drapes to minimize the accumulation of oxidizers Allow sufficient drying time for flammable skin prepping solutions Moisten sponges and gauze when used in proximity to ignition sources Is this a high-risk procedure Monitor oxygenation with pulse oximetry and, if feasible, inspired, exhaled, and/or delivered oxygen concentration. As exocrine glands, their function is variously to produce saliva, digestive enzymes (amylase), and lubrication, as well as to provide a bacteriostatic function. Indications for submandibular gland surgery include tumors, chronic sialadenitis refractory to medical treatment, and removal of impacted stones. The most frequent parotid disease warranting surgery is a benign neoplasm, frequently a pleomorphic adenoma. Superficial parotidectomy (complete or limited) with facial nerve dissection is the most commonly performed procedure for these lesions, although a simpler enucleation procedure is sometimes also performed. For this reason the surgical team usually requests that muscle relaxants be avoided after endotracheal intubation has been achieved. Inflate the endotracheal tube cuff with dyed normal saline to provide an early indicator of cuff rupture. Use a pre-prepared 50-mL syringe of saline to extinguish any fire, and flood the surgical field if a fire occurs. Inform the surgical team working on the airway of any situation in which high concentrations of O2 are being used. Remove the burning endotracheal tube* and drop it in the bucket of water, if available. Ventilate the patient with 100% O2 by facemask (or supraglottic airway if appropriate). Consider using a ventilating rigid bronchoscope; debris and foreign bodies should be removed. Provide supportive therapy, including ventilation and antibiotics, and extubate when appropriate. Consequently, general anesthesia with endotracheal intubation is usually required, although cases of parotid surgery performed using local anesthesia have been reported. Sufficient anesthetic depth and patient immobility are usually achieved using relatively large doses of opioid and inhaled anesthetics, with muscle relaxants avoided to allow facial nerve monitoring for both parotid and (less commonly) submandibular surgery. I frequently employ a single, small dose of rocuronium to facilitate endotracheal intubation, followed by sevoflurane anesthesia in conjunction with a remifentanil infusion. Finally, preservation of the facial nerve is of prime importance in these operations; consequently, the surgeon often must identify the facial nerve by using a nerve stimulator. The last of these can occur without desaturation, whereas hypoxia itself leads to arousal from sleep, with reopening of the airway and the intake of a breath. Severity is related to the number of these respiratory events per hour as determined by polysomnography. Commonly performed procedures include uvulopalatopharyngoplasty, uvulopalatal flap surgery, tonsillectomy and adenoidectomy, genioglossus advancement, maxillomandibular advancement, and other procedures. Possible comorbidities such as obesity (see also Chapter 71), metabolic syndrome, type 2 diabetes, coronary artery disease, or cor pulmonale should be identified. Chapter 85: Anesthesia for Ear, Nose, and Throat Surgery 2541 conditions such as macroglossia, redundant pharyngeal tissue, lingual tonsil hypertrophy, or an anterior larynx, all of which can make direct laryngoscopy difficult. Postoperative airway edema is another concern and constitutes another reason that it is wise to minimize respiratory depressants such as opioids and sedatives postoperatively. Confirmation of the clinical diagnosis is usually by barium swallow and/ or endoscopy. In the open (transcervical) approach, the diverticulum is exposed through a lateral neck incision and is then resected (diverticulectomy) or tacked superiorly to the prevertebral fascia (diverticulopexy). In the endoscopic approach, no skin incision is required; here the surgical procedure usually involves ablating the common wall between the pouch and the cervical esophagus by using an endoscopic stapler, surgical laser, or other means. First, patients are frequently older, with applicable comorbidities, such as coronary artery disease. Second, the possibility that food caught in the pouch could end up in the airway is a concern. Additionally, oral medications such as antihypertensives administered the day of surgery may lodge in the pouch and be aspirated. Perhaps preoperative evacuation of the pouch can be performed by applying external pressure before anesthesia, but this is not commonly done because of concerns of causing iatrogenic pulmonary aspiration. More commonly, the patient is positioned with a 30-degree head-up tilt before the induction of anesthesia. Although awake endotracheal intubation should provide excellent protection against the risk of aspiration of pouch contents, a theoretic concern exists that any coughing during the procedure, either from the use of transtracheal local anesthesia or from the instrumentation, could lead to regurgitation of pouch contents with possible aspiration. A more common technique is the use of rapid-sequence induction of anesthesia, usually with the modification that cricoid pressure is not used, for fear of discharging the pouch contents with the applied pressure. Some experts have expressed the concern that using succinylcholine, especially if it is not preceded by a nondepolarizing muscle relaxant, could produce muscle fasciculations that could cause pouch compression (see also Chapter 34). Finally, the procedure is occasionally performed using regional anesthesia with deep and superficial cervical plexus blocks (see also Chapter 57). Care should be taken to avoid perforation of the diverticulum, such as with blind placement of a nasogastric tube or during difficult tracheal intubation. During the surgical procedure, retraction of the carotid sheath may stimulate baroreceptors and initiate arrhythmias, especially bradycardia, whereas significant blood loss and air embolism may occur if major vessels are accidently cut. A smooth awakening from anesthesia that is free from coughing and straining is important to avoid the risks of neck hematoma and the attendant possibility of a compromised airway. Anatomic relationship of the diverticulum to the cricoid cartilage during application of cricoid pressure. In dire emergencies one may perform a cricothyrotomy,161,162 by entering the airway through the cricothyroid membrane. This is done either by inserting a narrow-bore transtracheal ventilation catheter percutaneously through the cricothyroid membrane and employing emergency high-pressure jet ventilation or by inserting a wider-bore tube of sufficient diameter to allow lowpressure ventilation through a conventional resuscitator bag. This second approach through the cricothyroid membrane can be achieved by using a vertical scalpel incision, identifying the cricothyroid membrane, cutting through the membrane with a horizontal stab incision, and placing (for example) a 6-mm inner-diameter tracheal tube. Alternately, one can use a commercial kit employing (for example) the Seldinger technique. In any event, the decision to perform a tracheostomy using local anesthesia is made jointly with the surgeon and depends on the extent of airway disease, the experience of the surgical team, and the degree to which the patient is able to tolerate lying supine with his or her head in extension. In some cases the procedure must be performed with the patient in a semiupright sitting position (see also Chapter 41).

Affected children usually have a blue sclera because of defective collagen production erectile dysfunction fast treatment 100 mg zudena purchase visa. Although osteogenesis imperfecta has been associated with malignant hyperthermia erectile dysfunction drugs side effects purchase zudena with a mastercard, this has not been verified by muscle biopsy (see also Chapter 43) impotence 25 years old discount zudena 100 mg buy on-line. Associated cardiac abnormalities include patent ductus arteriosus trazodone causes erectile dysfunction order genuine zudena, septal defects erectile dysfunction treatment without drugs generic zudena 100 mg amex, and acquired aortic regurgitation and cystic degeneration of the proximal aorta (see also Chapters 93 and 94). The fragility of connective tissue and bones in osteogenesis imperfecta demands extreme care in positioning and padding during anesthesia. The area under the blood pressure cuff must be padded, and for longer procedures insertion of an arterial catheter avoids the repeated inflation of the cuff and the risk for a humeral fracture. Because patients with osteogenesis imperfecta often have reduced mobility of the cervical spine, tracheal intubation must be achieved with minimal neck manipulation. The administration of succinylcholine should be avoided for the induction of anesthesia not only because of the theoretic risk for hyperkalemia and hyperthermia but also because muscle fasciculations may produce bony fractures. Patients with osteogenesis imperfecta should have a preoperative echocardiogram, and any abnormal findings should be managed accordingly. The bleeding status of patients with osteogenesis imperfecta should be evaluated preoperatively to prepare for the perioperative transfusion of platelets. Because of the risk for intraoperative hyperthermia and metabolic acidosis, patients with osteogenesis imperfecta should be aggressively hydrated, and, if necessary, active cooling should be instituted. Regional anesthesia is an attractive alternative to general anesthesia, but must be approached with caution to avoid bone punctures and intraosseous injections (see also Chapters 57 and 58). Cerebral Palsy Cerebral palsy is a nonprogressive motor impairment arising from lesions in the brain that occurred during the early stages of development-in utero (75%), at birth (10%), and soon after birth (15%) (see also Chapter 93). The cause of cerebral palsy remains unclear; however, intrapartum asphyxia, which was originally thought to be the major cause of the disease, may be responsible for only 10% of the cases. Perioperative infections and low birth weight may play a much more important role. Cerebral palsy is divided into four major classifications to describe the different movement impairments: spastic, athetoid/dyskinetic, ataxic, and mixed. Spastic cerebral palsy, which is the most common type, results from Osteogenesis Imperfecta Osteogenesis imperfecta is a rare autosomal dominant inherited disease that results in extremely brittle bones because of a defect or deficiency in type I collagen production. In the most extreme form, multiple fractures occur during delivery and are often fatal. Normal skeletal development requires stress from the musculature to attain proper shape and size. Without these stresses or with abnormal stresses, as in cerebral palsy, various angular joint deformities and gracile (thin) shafts and abnormal articular joints develop. Orthopedic surgeries often involve loosening of tight muscles (hip adductor and iliopsoas release), releasing fixed joints, straightening abnormal twists (derotational osteotomy of the femur), rhizotomies to reduce spasm, and spinal surgery to correct kyphoscoliosis. Patients with cerebral palsy have significant gastroesophageal reflux and poor laryngeal reflexes, placing them at risk for pulmonary aspiration. In most cases, surgical procedures in patients with cerebral palsy require general anesthesia with tracheal intubation, even if also accompanied by regional anesthesia to reduce the need for systemic anesthetics and to provide postoperative analgesia. Postoperative epidural analgesia with local anesthetic alone eliminates the potential complications of opioids and permits continued dosing with diazepam to relieve spasms. Regional anesthesia also may shorten emergence from general anesthesia, which can be prolonged because of inherent cerebral damage and the effects of antiseizure medications. Postoperative pulmonary complications are common owing to multiple causes, including aspiration, poor respiratory effort, and reduced thoracic compliance. After major surgical procedures, cerebral palsy patients should be observed in a monitored setting for several hours. It is prudent, however, to recognize the warnings of Benumof68: "Use of regional anesthesia in the patient with a recognized difficult airway does not solve the problem of the difficult airway; it is still there. A further advantage to the use of regional anesthetic techniques for orthopedic surgery has been the suggestion of decreased intraoperative blood loss. The epidural group showed the smallest blood loss, but no significant relationship between arterial blood pressure and blood loss was identified. The authors suggested that epidural anesthesia reduces venous blood pressure (measured in the operative wound), which is the significant factor in determining surgical bleeding. The controversy as to whether regional anesthesia has an advantage over general anesthesia has been debated for decades without clear evidence documenting the superiority of one method. Regional anesthesia avoids manipulation of the airway, and conscious patients can Chapter 79: Anesthesia for Orthopedic Surgery 2395 rather than within 4 hours or less preoperatively or 4 hours or less postoperatively (grade 1B). Fondaparinux, a synthetic pentasaccharide, is a selective inhibitor of factor Xa and has a plasma half-life of approximately 18 hours. When administered once daily, fondaparinux produces a predictable anticoagulant response. Dabigatran will prolong the activated partial thromboplastin time, but this effect is not linear and should not be used as an indication of the degree of anticoagulation. We recommend against the routine use of monitoring of the antiXa level (grade 1A). Education of the entire patient care team is necessary to avoid potentiation of the anticoagulant effects. The presence of blood during needle and catheter placement does not necessitate postponement of surgery. Management is based on total daily dose, timing of the first postoperative dose and dosing schedule (grade 1C). The second postoperative dose should occur no sooner than 24 hours after the first dose. No additional hemostasis-altering medications should be administered because of the additive effects. Caution should be used when performing neuraxial techniques in patients recently discontinued from long-term warfarin therapy. In patients who are likely to have an enhanced response to the drug, we recommend that a reduced dose be administered. Algorithms have been developed to guide physicians in the appropriate dosing of warfarin based on desired indication, patient factors, and surgical factors. These algorithms may be extremely useful in patients at risk for an enhanced response to warfarin (grade 1B). Neurologic testing of sensory and motor function should be performed routinely during epidural analgesia for patients on warfarin therapy. To facilitate neurologic evaluation, we recommend that the type of analgesic solution be tailored to minimize the degree of sensory and motor blockade (grade 1C). This value was derived from studies correlating hemostasis with clotting factor activity levels greater than 40%. We suggest that neurologic assessment be continued for at least 24 hours after catheter removal for these patients (grade 2C). We can make no definitive recommendation regarding the management to facilitate removal of neuraxial catheters in patients with therapeutic levels of anticoagulation during neuraxial catheter infusion (grade 2C). Limited data are available to determine which patients are inappropriate adult ambulatory patients. In most centers, morbidly obese patients and patients with sleep apnea require monitored observation overnight after procedures in which systemic anesthetics and analgesics have been administered. It follows then that medically unstable patients are not outpatient surgical candidates. In a prospective study of 1088 patients for ambulatory surgery, Pavlin and co-workers80 reported that the most important factors in determining discharge time were pain, nausea and vomiting, unresolved neuraxial blocks, and urinary retention. This study emphasizes the role of anesthesia in prolonging ambulatory surgical stay. General anesthesia is a safe and effective anesthetic for arthroscopic surgery, but it has been associated with increased postoperative nausea and vomiting and pain. A properly designed regional anesthetic may reduce the importance of some of these factors. Arthroscopic knee surgery can be performed with a combination of extraarticular and intraarticular injections of local anesthetics. Short-duration local anesthetics are often combined with longer acting local anesthetics (bupivacaine) and morphine to provide postoperative analgesia. Intraarticular morphine does not provide significant additional analgesia after arthroscopic knee surgery. For more involved arthroscopic procedures, such as an anterior cruciate ligament repair, surgical relaxation is also required. Spinal anesthesia with pencil-point atraumatic needles to prevent postdural puncture headaches provides excellent operating conditions for these procedures. A dose of 45 mg of isobaric spinal mepivacaine results in a mean motor block of 142 ± 37 minutes. Using 30 to 40 mg of spinal chloroprocaine, Yoos and Kopacz81 reported 155 ± 34 minutes to ambulation in outpatient surgical patients. For postoperative analgesia after anterior cruciate ligament repairs, a femoral nerve block with a long-acting local anesthetic is superior to intraarticular injections. Because the quadriceps muscle is blocked, it is important for the patient to be fitted with a knee brace before ambulation. Blocking the saphenous nerve in the adductor canal may provide postoperative analgesia without also interfering with early ambulation. The patient can be placed in either the supine or the lateral position (operative side up) with 50 to 75 lb of traction applied to the operative limb to gain access to the joint with the arthroscope. In positioning the patient, the anesthesiologist must ensure that the perineal post is padded and not compressing the pudendal nerve and that excessive traction for prolonged periods is not applied (see also Chapter 41). Because complete muscle relaxation is required for the procedure, the patient must have either a general anesthetic or a neuraxial block. A normal intravascular blood volume should be restored before anesthesia and surgery; this is best achieved with central venous catheter monitoring. Central venous catheter monitoring also may prevent overhydration, which can precipitate congestive heart failure. Placement of an arterial catheter permits accurate blood pressure monitoring during surgery and the ability to follow serial arterial blood gases. Hypoxemia, possibly owing to fat embolization, has been a major determinant of mortality in these patients. Several studies have reported improved outcome with regional anesthesia compared with general anesthesia in these patients. Epidural anesthesia with postoperative analgesia is usually not indicated, because in most cases aggressive postoperative anticoagulation is instituted. Long-acting benzodiazepines should be avoided because of their association with postoperative confusion. Acute mortality directly related to the pelvic fracture may result from retroperitoneal bleeding. An indication for emergency exploratory surgery after a pelvic fracture would include persistent hypotension and increasing abdominal girth. Injuries to the bladder and urethra are also often associated with pelvic fractures; thus urology clearance is usually indicated before inserting a Foley catheter. Recent reports suggest that the optimal time for stabilization of a pelvic fracture is within the first week of trauma; however, associated injuries often delay the operation. An optimal anesthetic may be the combination of a general anesthetic with the placement of an epidural catheter for postoperative analgesia. Because iatrogenic sciatic nerve injury is the most frequent surgical complication (18%), the use of intraoperative neuromuscular monitoring precludes dosing of the epidural catheter during the procedure and dictates waiting to dose the catheter until after the preservation of lower extremity movement and sensation has been confirmed. In most cases, these patients require monitoring with arterial and central venous catheters, as well as the placement of large-gauge venous catheters in the event of sudden surgical hemorrhage. Hip Fractures Hip fractures in older individuals are common (1 in 50 individuals older than 60 years of age), and as previously stated are associated with significant morbidity and mortality (1-year mortality of 30%). Postoperative confusion and delirium are common, reported in 50% of older patients after the repair of hip fractures and associated with increased mortality. In one study, the incidence of hyponatremia was 4% and was associated with a sevenfold increase in hospital mortality. Although preoperative preparation is essential, delaying surgery may exacerbate these problems and increase the incidence of complications. Early surgery (<12 hours) has resulted in lower pain scores, decreased length of hospital stay, and reduced perioperative complications. Using geriatric services has been shown to improve outcomes, especially better lower limb function. The anterior approach offers the advantage of exposure without violation of the muscles, but restricts full access to the femur, with the risk for lateral femoral cutaneous nerve injury. The lateral posterior approach provides excellent exposure to the femur and the acetabulum with minimal muscle damage, but increases the risk for posterior dislocation. Most surgeons prefer the lateral posterior approach, which places the patient in the lateral decubitus position, surgical side up, for the operation. The anesthesiologist must be aware that this position may compromise oxygenation, particularly in obese and severely arthritic patients, as a result of ventilation-perfusion mismatch. In addition, to prevent excessive pressure on the axillary artery and brachial plexus by the dependent shoulder, an anterior roll or pad must be placed beneath the upper thorax. The nerve supply to the hip joint includes the obturator, inferior gluteal, and superior gluteal nerves. The hypotensive events that follow bone marrow embolization should be treated with epinephrine. In addition, the hemodynamic consequences of bone marrow embolization can be ameliorated through high-pressure pulsatile lavage of the femoral canal and drilling a vent hole in the femur before prosthesis insertion.

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