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However buy 130mg viagra extra dosage overnight delivery, the consequences of myocardial and cerebral ischemia are the same as for the adult generic viagra extra dosage 200mg free shipping, and the basic approach to the unresponsive victim is similar discount viagra extra dosage 120mg on-line. The specific anatomic and physiologic considerations necessary for the child will be familiar to anesthesiologists. The special circumstance of neonatal resuscitation is discussed in Chapters 41 and 42. The problem of airway management in the infant is well known to the anesthesiologist. Effective ventilation is especially critical because respiratory problems are frequently the cause for arrest. Mouth-to-mouth or mouth-to- nose and mouth (for infants) can be used as well as bag-valve-mask devices until intubation is possible. Cardiac compression in the infant is provided with two fingers on the midsternum or by encircling the chest with the hands and using the thumbs to provide compression. For both infants and 4200 children, compressions should be at least one-third the depth of the chest at a rate of 100 to 120/min. For a single rescuer, a 30:2 compression-to- ventilation ratio should be used and with two or more rescuers a 15:2 ratio is recommended. Although defibrillation is less frequently necessary in children, the same principles apply as in the adult. However, the recommended starting energy is 2 J/kg (monophasic or biphasic), which is doubled if defibrillation is unsuccessful. Considerations for drug administration are the same as for the adult, except that the interosseous route in the anterior tibia is a particularly attractive option in small children. Drug therapy is similar to that of the adult but plays a larger role because electrical therapy is less often needed (Table 58-3). The pediatric algorithms for bradycardia and tachycardia are shown in Figures 58-5 and 58-6. Table 58-3 Medications for Pediatric Resuscitation Postresuscitation Care The major factors contributing to mortality following successful resuscitation are progression of the primary disease and cerebral damage suffered as a result of the arrest. For optimal outcome, successful restoration of spontaneous circulation must be followed 4203 by correction of reversible causes of arrest, including immediate coronary reperfusion and aggressive supportive care (Fig. Any cardiac arrest, even of brief duration, causes a generalized decrease in myocardial function similar to the regional hypokinesis seen following periods of regional ischemia. This is usually referred to as global myocardial stunning and can be mitigated with inotropic agents, if necessary. Active management following resuscitation appears to mitigate postischemic brain damage and improve neurologic outcomes. Although a significant number of patients have severe neurologic deficits following resuscitation, aggressive brain-oriented support does not seem to increase the proportion surviving in vegetative states. When flow is restored following a period of global brain ischemia, three stages of cerebral reperfusion are seen in the ensuing 12 hours. Immediately following resuscitation, there are multifocal areas of the brain with no reflow. Within 1 hour, there is global hyperemia followed quickly by prolonged global hypoperfusion. Elevation of intracranial pressure is unusual following 4205 resuscitation from cardiac arrest. However, severe ischemic injury can lead to cerebral edema and increased intracranial pressure in the ensuing days. Nonconvulsive seizures are common postresuscitation with or without therapeutic hypothermia. Postresuscitation support is focused on providing stable oxygenation and hemodynamics to minimize any further cerebral insult. A comatose patient should be maintained on mechanical ventilation for several hours to ensure adequate oxygenation and ventilation. Restlessness, coughing, or seizure activity should be aggressively treated with appropriate medications, including neuromuscular blockers, if necessary. Oxygen free radicals are a major cause of reperfusion injury and postresuscitation hyperoxia may contribute to poor neurologic outcome. Because cerebral autoregulation of blood flow is severely attenuated after cardiac arrest, both prolonged hypertension and hypotension are associated with a worsened outcome. Hyperglycemia during cerebral ischemia is known to result in increased neurologic damage. Although it is unknown if high serum glucose in the postresuscitation period influences outcome, it seems prudent to control glucose in the 100 to 150 mg/dL range. Specific pharmacologic therapy directed at brain preservation has not been shown to have further benefit. Some animal trials of barbiturates were promising, but a large multicenter trial of thiopental found no improvement in neurologic status when this drug was given following cardiac arrest. Animal studies were encouraging, but a clinical trial found no improvement in outcome. These are the first studies to document improved neurologic outcome with a specific postarrest intervention. The International Liaison Committee on Resuscitation 4208 now recommends targeted temperature management for unconscious adult patients with return of spontaneous circulation after cardiac arrest at a constant temperature between 32° and 36°C for at least 24 hours. Most patients who completely recover show rapid improvement in the first 48 hours. It is generally agreed that poor outcome should not be predicted prior to 72 hours after return of spontaneous circulation in patients not undergoing hypothermia and that time should be extended for those receiving hypothermia. But the false positive rate (a good outcome when a poor outcome is predicted) for this sign is high. Confirmatory signs that have nearly a 0% false positive rate are the absence of a pupillary light reflex at 72 hours and absence of the N20 wave on somatosensory evoked potentials at 24 to 72 hours. Artificial respiration by mouth to mask method: A study of the respiratory gas exchange of paralyzed patients ventilated by operator’s expired air. A comparison of the mouth-to-mouth and mouth- to-airway methods of artificial respiration with the chest-pressure arm-lift methods. Termination of ventricular fibrillation in man by an externally applied electric shock. Heart disease and stroke statistics 2008 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. A comparison of cardiopulmonary resuscitation with cardiopulmonary bypass after prolonged cardiac arrest in dogs: reperfusion pressures and neurologic recovery. Limitations of open-chest cardiac massage after prolonged, untreated cardiac arrest in dogs. Quality of bystander cardiopulmonary resuscitation influences outcome after prehospital cardiac arrest. Treatment of out-of-hospital cardiac arrest with rapid defibrillation by emergency medical technicians. Use of the automatic external defibrillator in the management of out-of-hospital cardiac arrest. Interruptions of chest compressions during emergency medical systems resuscitation.

The radial nerve is located beneath this intercondylar line quality 120 mg viagra extra dosage, approximately 1 to 2 cm lateral to the biceps tendon 150 mg viagra extra dosage with amex. Elbow extension should not be elicited since the branch to the long head of the triceps has diverged proximally order viagra extra dosage 200mg without prescription. The radial nerve can first be located proximally at the level of the spiral (radial) groove of the humerus 2413 where it lies immediately adjacent to the humerus and posteromedial to the deep brachial (profunda brachii) artery of the arm. The patient’s arm should be internally rotated and placed with the hand over the abdomen on the opposite side of the body. Subsequent tracing of the nerve from this humeral location to the anterolateral elbow may facilitate its precise localization. The probe can be rotated slowly to scan the nerve both in the longitudinal and transverse planes at the elbow for confirmation of its location. The nerve appears oval and predominantly hyperechoic and is located in the posterior aspect of the humerus and immediately adjacent to the small, pulsatile deep brachial (profunda brachii) artery (as verified with Doppler). At a point just proximal to the anterior compartment of the elbow, the humerus appears to have changed shape and appears smaller and almost rectangular in cross- section. The hyperechoic radial nerve now lies at some distance from the humerus, is sandwiched between the brachialis and brachioradialis muscles, and appears oval-shaped. The nerve should be blocked slightly above the elbow since it divides into deep and superficial branches approximately 2 cm above the elbow. The block needle is advanced to approach the target nerve on its side, preferably avoiding direct needle contact with the nerve. The aim is to inject approximately 5 mL of local anesthetic and observe spread around the nerve circumferentially. The ideal placement will be a few centimeters above the elbow where the nerve has not yet divided into superficial and deep branches. Clinical Pearls • Needle contact with the humerus indicates that the needle is too deep, whereas deep needle penetration without bone contact indicates that the needle is lateral to the humerus (beyond the bone). At the wrist, 3 mL of solution is injected into the “anatomic snuffbox” formed by the tendons of the extensor pollicis longus and extensor pollicis brevis tendons. A subcutaneous wheal is then raised from this point, extending over the dorsum of the wrist 3 to 4 cm onto the back of the hand. This approach is suboptimal for most procedures since the nerve divides immediately beyond the elbow and continues as the superficial radial (sensory) and deep posterior interosseous (motor) nerves. Median Nerve The median nerve can be blocked at the midline of the anterior elbow or at the mid-to-distal aspect of the anterior forearm (Fig. The nerve is located adjacent (medial) to the brachial artery at the elbow, facilitating its localization here. In the forearm, the nerve can be located at its position lateral to the ulnar nerve. The median nerve supplies the skin anteriorly on the medial surface of the thumb, palm, and digits two to four, and posteriorly on the distal third of the second to fourth digits. It causes flexion at the metacarpophalangeal joints and extension at the interphalangeal joints of digits two and three. The nerve innervates muscles which produce flexion and opposition of the thumb, middle, and index fingers and pronation and flexion 2415 of the wrist. Figure 36-24 Illustration of the anterior forearm showing the courses of the median and ulnar nerves. The ulnar artery is a reliable landmark to localize the ulnar nerve when using ultrasound imaging. Procedure Using Nerve Stimulation Technique At the elbow: • Landmarks: As with radial nerve block, an intercondylar line is drawn, and the nerve is located where this line crosses the pulsation of the brachial artery, usually 1 cm to the ulnar side of the biceps brachii tendon. Figure 36-25 Arrangement of relevant anatomy for ultrasound-guided median and ulnar nerve block. For ulnar nerve block, the ideal location to avoid arterial puncture is where the nerve has yet to fully approach the ulnar artery. At the anterolateral forearm, the nerve lies lateral to the ulnar nerve and 2417 artery (localizing the ulnar nerve first will help identify the median nerve). Deep to the neurovascular structures lies the musculature of the superior aspect of the elbow (pronator teres and brachialis muscles) as a hypoechoic homogeneous mass. Clinical Pearls • The median nerve lies deep to the flexor retinaculum at the wrist, and there is always the potential risk of causing carpal tunnel syndrome due to elevated pressure within the tunnel following injection. For this reason, the elbow or forearm locations for blocking the median nerve are the more logical choices. If only the palmaris longus muscle can be felt, the nerve lies just to the radial side of its tendon. A skin wheal is raised, and a needle is inserted until it pierces the deep fascia. An injection of 3 to 5 mL of local anesthetic is sufficient to produce anesthesia. In this case, the needle should be reinserted after applying pressure to the puncture site until hemostasis is achieved. Ulnar Nerve In the periphery, the ulnar nerve can be blocked at the elbow, forearm, or wrist. Ulnar nerve block may be used for rescue analgesia or surgical anesthesia for surgery on the fifth digit. At the junction of the distal third and proximal two-thirds of the medial forearm, the nerve is commonly located just medial to the pulsatile ulnar artery (Fig. The ulnar nerve supplies muscles that produce flexion of the ring (fourth) and little (fifth) fingers and ulnar deviation of wrist. It innervates the skin over the medial surface (anterior and posterior) of the hand and digits four and five. Before performing the block, the patient’s arm should be flexed at the elbow by 30 degrees and the forearm supinated. Procedure Using Nerve Stimulation Technique At the elbow: • Anesthetizing the ulnar nerve at the elbow may be uncomfortable for the patient. Only a small volume (1 to 4 mL) of local anesthetic should be injected if performing the block at this location. Transcutaneous electrical stimulation17 or percutaneous electrode guidance18,19 can be used to locate the nerve. Once the nerve has been localized, an insulated needle attached to a nerve stimulator is inserted perpendicular to the plane of the forearm, and appropriate motor responses are sought. The appropriate responses for ulnar nerve block at this location are flexion of the ring (fourth) and little (fifth) fingers and ulnar deviation of the wrist. Injection of 5 mL local anesthetic is sufficient to block the nerve at the forearm. The probe is placed transversely just above the mid- 2419 forearm level to view the ulnar nerve in short axis as it approaches the ulnar artery. The nerve is positioned above the ulna and the belly of the flexor carpi ulnaris, on the anterior surface of the arm, rather than medially to contact the bone. The operator should scan downward slowly until the nerve and pulsatile artery are viewed adjacent to each other (Doppler may be valuable here) and retract the scanhead slightly so the artery and nerve appear clearly as separate structures (Fig.

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This gave rise to the concept of a “decisive period” in which antibiotics will be effective buy viagra extra dosage 130 mg cheap, which remains a guiding principle of antibiotic prophylaxis generic 150mg viagra extra dosage amex. This demonstrated the crucial role of local perfusion in delivering antibiotics to the site purchase line viagra extra dosage. Thus, the decisive period for oxygen is considerably longer than that for antibiotics. Figure 8-3 The effect of oxygen and/or antibiotics on lesion diameter after intradermal injection of bacteria into guinea pigs. Note that at every level, oxygen adds to the effect of antibiotics and that increasing oxygen in the breathing mixture from 12% to 20% or from 20% to 45% exerts an effect comparable to that of appropriately timed antibiotics. Louis, Harvey Bernard and William Cole, reported on the first controlled clinical trial of the efficacy of30 antibiotic prophylaxis in 1964 and demonstrated a benefit in abdominal operations. Thereafter, numerous clinical trials were performed with somewhat variable results. Eventually these served to define the timing and population in which prophylactic antibiotics work. By the 1970s, antibiotic 514 prophylaxis for high-risk surgery—meaning clean-contaminated and contaminated cases—was becoming well accepted and widely used, although some skeptics remained. The best results, though only by a small margin and not statistically significant, were within 0 and 60 minutes of surgery, and this subsequently became the clinical standard. Antibiotic prophylaxis has now become standard for surgeries in which there is more than a minimum risk of infection. Although not every surgery and situation has been studied, a strong rationale for the approach to prophylactic antibiotics has emerged. The agent for antibiotic32 prophylaxis must cover the most likely spectrum of bacteria presented in the surgical field. The most common surgical-site pathogens in clean procedures are skin flora, including Staphylococcus aureus and coagulase-negative staphylococci (e. In clean-contaminated procedures, the most common pathogens include gram-negative rods, and enterococci in addition to skin flora. Nevertheless, it is not recommended that vancomycin be used as a routine agent for surgical antimicrobial prophylaxis. The number of infections and the number of patients for each hourly interval appear as the numerator and denominator, respectively, of the fraction for that interval. The trend toward higher rates of infection for each hour that antibiotic administration was delayed after the surgical incision was significant (z score = 2. The timing of prophylactic administration of antibiotics and the risk of surgical-wound infection. The exact timing for the administration of the antibiotic depends on the pharmacology and half-life of the drug. It has been suggested that administration of prophylactic antibiotics is ideal within 30 minutes to 1 hour of incision. Giving the antibiotics too early (so that the incision is more than 60 minutes after the dose) is a recurrent issue at many hospitals, especially in cases that require complex patient positioning. Providing timely prophylactic antibiotics is relatively uncomplicated for antibiotics that can be given as a bolus dose (e. For drugs like vancomycin that require infusion over an hour or more, coordination of administration is more complex. In general, it is considered acceptable if the infusion is started within 120 minutes before incision. When a tourniquet is used, the infusion must be complete prior to inflation of the tourniquet. An appropriate dose based on body weight and volume of distribution should be given. Depending on the half-life, antibiotics should be repeated during long operations or operations with large blood loss. For example, cefazolin is normally dosed every 8 hours but the dose32 should be repeated every 4 hours intraoperatively. Finally, prophylactic32 antibiotics should be discontinued by 24 hours following surgery if postoperative dosing is selected at all. Prolonging the course of prophylactic antibiotics does not reduce the risk of infection but does increase the risk of adverse consequences of antibiotic administration, including resistance,32 C. Table 8-5 General Recommendations for Antibiotic Prophylaxis Because they have access to the patient during the 60 minutes prior to incision and can optimize timing of administration, anesthesiologists should work in consultation with the surgeon to use guidelines determined by the 517 local infection control committee to take initiative for administering prophylactic antibiotics. Physician and hospital reimbursements are increasingly tied to such performance measures, meaning anesthesiologists also have an economic interest in ensuring adherence to guidelines. Mechanisms of Wound Repair Wound healing is a complex process, requiring a coordinated repair response including inflammation, matrix production, angiogenesis, epithelialization, and remodeling (Fig. Systemic factors such as medical comorbidities, nutrition, sympathetic nervous35 system activation, and age36 37–39 have a substantial effect on the repair process. Local environmental factors in and around the wound including bacterial load, degree of inflammation, moisture content, oxygen40 41 tension, and vascular perfusion also have a profound effect on healing. Oxygen is a rate-limiting component in leukocyte- mediated bacterial killing and collagen formation because specific enzymes require oxygen at a partial pressure of at least 40 mmHg. This response initiates a sequence of events that starts with any source of injury that disrupts homeostasis in the local environment and eventually leads to healing. Wound healing is described in four overlapping phases: hemostasis, inflammation, proliferation, and remodeling. Each phase is composed of50 complex interactions between host cells, contaminants, cytokines, and other chemical mediators that, when functioning properly, lead to repair of injury. These processes are highly conserved across species, indicating the critical51 importance of the inflammatory response that directs the process of cellular/tissue repair. When any component of healing is disturbed and interrupts the orderly progression of repair, wound failure may result. The initial result is coagulation, which prevents exsanguination but50 also widens the area that is no longer perfused. Polymorphonuclear leukocytes arrive at the wound almost immediately and are followed by macrophages at 24 to 48 hours. These inflammatory cells activate in response to endothelial integrins, selectins, cell adhesion molecules, cadherins, fibrin, lactate, hypoxia, foreign bodies, infectious agents, and growth factors. This early inflammatory phase is53 characterized by erythema and edema of the wound edges. Activated neutrophils and macrophages also release proteases, including neutrophil elastase, neutrophil collagenase, matrix metalloproteinase, and macrophage metalloelastase. These proteases degrade damaged extracellular50 matrix components to allow their replacement. Proteases also degrade the basement membrane of capillaries to enable inflammatory cells to migrate into the wound. In wounds, local blood supply is compromised at the same time that metabolic demand is increased.

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General anesthesia is indicated in the presence of uncontrolled hemorrhage and/or severe coagulation abnormalities viagra extra dosage 130mg generic. Neuraxial anesthesia purchase 120 mg viagra extra dosage visa, usually continuous epidural anesthesia purchase cheap viagra extra dosage online, has been successfully used for hysterectomy in planned, controlled situations. A saddle block is an option for anesthesia when dilation and curettage for treatment of postpartum hemorrhage is indicated and the patient is hemodynamically stable. All of these tasks may be challenging in the parturient and consideration should be given to performing them in advance of hemorrhage when hemorrhage is anticipated. Prompt transfusion of blood component therapy is crucial for replacement of blood loss, maintenance of tissue oxygenation, and correction of coagulopathy. In recent years, transfusion rates for postpartum hemorrhage have increased 92% in the United States. Early administration of platelets and cryoprecipitate has also become common in hemostatic resuscitation protocols for major traumatic hemorrhage, and crystalloid and colloid administration is minimized in favor of blood products (see Chapter 53). Hypothermia, metabolic acidosis, and coagulopathy commonly occur in traumatic and obstetric hemorrhage. Because of these commonalities, it has become common to extend these successful transfusion practices from the trauma literature to obstetric practice. Transfusion of cryoprecipitate or better, fibrinogen concentrate, should be incorporated early in obstetric hemorrhage because decreased fibrinogen levels strongly correlate with increased severity of postpartum hemorrhage. Other options are available to decrease transfusion requirements and reduce blood loss. Intraoperative cell salvage, formerly shunned because of concerns about the risk of amniotic fluid contamination of red cells, has been implemented safely during cesarean section in many centers. The antifibrinolytic drug tranexamic acid has been shown to decrease bleeding in both elective cesarean section and postpartum hemorrhage and is recommended for early use in resuscitation by a European task force131; however, further studies are needed to confirm its safety. Medical and surgical advancements have changed the types of cardiac problems seen in pregnancy. Patients with congenital heart disease are reaching childbearing age, and the number of patients with rheumatic heart disease has declined. Older parturients may present with aortic stenosis and insufficiency associated with a bicuspid aortic valve. The increase in maternal blood volume, which occurs at 20 to 24 weeks of gestation, may also precipitate cardiac decompensation. During labor, cardiac output increases progressively above antepartum levels; with each uterine contraction, approximately 200 mL of blood moves into the central circulation. Consequently, stroke volume, cardiac output, and left ventricular work increase, and each contraction consistently increases cardiac output by 10% to 25% above that of uterine diastole. The greatest change occurs immediately after delivery of the placenta, when cardiac output increases to an average of 80% above prepartum values; in some patients, it may increase 2884 by as much as 150%. Evaluation of pre-existing heart disease is crucial and a multidisciplinary approach is necessary when managing patients with complicated cardiac disease during pregnancy and parturition. Labored breathing and venous stasis from aortocaval compression may mimic pulmonary and peripheral edema associated with congestive heart failure. Finally, elevation of the diaphragm causes the heart to rotate, signs of which may be mistaken for cardiac hypertrophy. For the anesthesiologist, it is particularly important to understand how the hemodynamic consequences of different anesthetic techniques might adversely affect mothers with specific cardiac lesions. Exceptions are patients with pulmonary hypertension, right-to-left shunts, or coarctation of the aorta. Because hemodynamic changes observed during labor and delivery persist into the postpartum period, if used, invasive monitoring should continue for 24 to 48 hours postpartum. Congenital Heart Disease Many patients with successful surgical repair of congenital heart defects are asymptomatic with minimal cardiac findings. Patients with uncorrected or partially corrected lesions may have serious cardiac decompensation with pregnancy. This includes patients with corrected tetralogy of Fallot who may have recurrence of a small ventricular septal defect or develop outflow obstruction. Neuraxial labor analgesia is recommended to minimize hemodynamic changes associated with pain. Patients with corrected ventricular septal defects or atrial septal defects require no special care, nor do those with small asymptomatic atrial septal defects or ventricular septal defects. Large ventricular septal defects or atrial septal defects are associated with pulmonary hypertension. Eisenmenger syndrome occurs when uncorrected left-to-right shunt results in pulmonary hypertension, which, when severe, reverses flow to a right-to- 2885 left shunt. Pregnancy is not well tolerated and mortality can approach 30%, most commonly from embolic phenomena. Implementing labor analgesia that does not lead to deleterious hemodynamic changes is a challenge; opioid-based neuraxial techniques (e. Cesarean delivery is most often accomplished under general anesthesia in women with Eisenmenger syndrome. It should be recognized that arm-to- brain circulation times are rapid owing to right-to-left intracardiac shunts; drugs given intravenously have a rapid onset of action. In contrast to parenteral drugs, the rate of rise of arterial concentrations of inhaled drugs is slow because of decreased pulmonary blood flow. The myocardial depressant and vasodilating actions of volatile drugs may be hazardous in patients with Eisenmenger syndrome, and nitrous oxide, which may increase pulmonary vascular resistance, should be avoided. Valvular Heart Disease The decrease in incidence of rheumatic heart disease in the developed world has resulted in fewer parturients with valvular heart disease. Table 41-3 summarizes the management goals of patients with valvular heart disease. There is, however, concern that pregnancy hastens the rate of valve deterioration. Compared to heparin, warfarin is associated with a lower incidence of thrombosis, but also an unacceptable fetal risk. Pulmonary hypertension is defined as mean pulmonary artery pressure over 25 mmHg at rest or 30 mmHg with exercise. Vaginal delivery is associated with smaller hemodynamic shifts and less risk for bleeding. However, emergency cesarean delivery for maternal or fetal deterioration may be needed. Planned cesarean delivery may offer the advantages of ensuring optimal conditions and the availability of experienced staff. Pain during labor and vaginal delivery is especially detrimental because it may further increase pulmonary vascular resistance and decrease venous return.

Note the large mass of fibrin in Bowman’s space viagra extra dosage 200 mg sale, which is the result of capil- Fig purchase viagra extra dosage 120 mg free shipping. Surrounding the fibrin mass are a few epithelial ence of an extraglomerular cellular reaction following capillary loop cells cheap 120 mg viagra extra dosage visa, whose numbers will increase rapidly, forming a cellular crescent disruption. It is collapsed, and its structure is difficult to assess by hematoxylin and eosin stain 6. Crescents form after disruption or strated readily in the active stage of necrotizing injury and crescent for- necrosis of the capillary loop basement membrane, a finding identified mation with direct immunofluorescence for fibrinogen. Fibrin is beginning to spill into Bowman’s space, centic process but does not allow identification of the underlying dis- and a cellular reaction (crescent) has just begun to form. In the early crescentic lesions, fibrin may be abundant and nicely demonstrated with trichrome Fig. Over time, the fibrin breaks down and becomes inconspicuous as and has a stringy appearance on electron microscopy. The fibrin is enveloped by cells of the through a fibrocellular, then a fibrous, stage as the cellularity diminishes cellular crescent and matrix dominates the lesion. Note that only a remnant of the glomerular tuft is present; most of ease is a possibility. Bowman’s space is filled with red cells and fibrin Bowman’s space representing the initial phase of organization of the with an early cellular response. Complement may be linear or interrupted in its stain- have one or more multinucleated giant cells of histiocytic lineage. Immuno fl uorescence for IgG glomerulus contains one multinucleated giant cell in the center. Although giant cells may be seen in granulomatosis with polyangiitis, they are very rare in that context as well as in other glomerular diseases with crescent formation 6. Patients with together in a category of renal disease known as the “colla- Alport’s syndrome initially present with hematuria but pro- gen nephropathies. Only the typical ultra- structural findings of these entities are shown in the follow- ing illustrations. Electron microscopy in Alport’s syn- drome shows variable segments of glomerular capillary loop basement membrane thinning and thickening. Rarified foci with tiny electron-dense granulations also may be observed, but often representing an X-linked disorder caused by mutations these are not present in this image 236 6 Glomerular Diseases 6. Often which patients have hypoplastic or absent patella, bony there is a family history of hematuria. Thin basement mem- abnormalities of elbows, dystrophic fingernails and toenails, brane nephropathy is a benign nonprogressive disorder in the and iliac horns. Approximately 50 % of patients develop pro- vast majority of patients; however, rare progressive cases teinuria, although progression to renal failure affects less have been reported. To qualify for a diagnosis of thin base- logic features are nonspecific, with glomerulosclerosis and ment membrane nephropathy, patients must have hematuria secondary tubulointerstitial scarring. Tannic acid or phosphotungstic acid staining enhances the visibility of the collagen fibers and their banded periodicity. Electron microscopy in nail-patella syndrome shows lucent foci in the capillary loop basement membrane Fig. Within these foci are collagen copy in thin basement membrane nephropathy simply shows general- fi bers (arrow). Generally, there is preservation of the podocyte foot pro- of their foot processes cess because patients do not have significant proteinuria. The banded collagen fibers (arrow) are revealed most readily when sections are stained with phosphotung- stic acid, as in this example. However, in smoldering proteinuria, hematuria, hypertension, and renal failure, and or indolent cases, these findings may be minimally abnormal most develop end-stage kidney disease. Electron microscopy reveals short curvilinear collagen giopathic hemolytic anemia. It is a food-borne illness usually secondary to verotoxin-producing bacteria, especially Escherichia coli. It often is the result of genetic or acquired disorders of one of several alternative complement pathway regulatory proteins. It has a with phosphotungstic acid shows that the thickening is the result of poor prognosis, with a significant risk of renal failure and short curvilinear segments (arrow) of subendothelial collagen fibers. These are associated with accumulation of electron-dense material that is not immune deposits. A variety of other clinical disorders have thrombotic Electron micrograph microangiopathy as a primary morphologic finding (Table 6. None has distinguishing morphologic features, so clinical information is critical to the diagnosis. Thrombotic microangiopathies of all causes may have a range of acute and chronic features. The acute lesions include necrosis of endothelial cells, vascular smooth muscle cells, and glomer- ular mesangial cells, leading to microvascular thrombosis and mesangiolysis. The chronic lesions represent repair that leads to vascular occlusion and capillary loop basement membrane duplication. Acute thrombotic microangiopathy may affect glom- eruli, arterioles, and small arteries. In this example, there is afferent arteriolar thrombosis (arrow) that has extended into the glomerulus, Fig. Biopsy showed thrombus containing numerous fragmented red blood cells acute thrombotic microangiopathy affecting this afferent arteriole 6. This arteriole shows a chronic occlusive lesion result- In addition, cryoglobulinemic glomerulonephritis occa- ing from fibrin breakdown and organization. The severely thickened sionally may have structured microtubular deposits (see intima has obliterated the lumen (arrow). Structured immune complex deposits also are encountered occasionally in patients with lupus glomerulonephritis (i. Renal involvement causes nephrotic syndrome and invariably is a relentless progressive disorder. Many patients have extrarenal disease that may have greater prognostic importance, especially with cardiac involvement. More than 20 amyloidotic proteins have been identified, and the list will continue to expand. The thrombosis has resolved, but the intima is severely thick- most common form of amyloid is a family of hereditary ened with myointimal cell ingrowth and abundant loose basophilic ground substance, often referred to as mucoid intimal thickening. Amyloid may completely lack affinity for the silver stain, appearing as nonstained zones of glomerular tuft expansion, as shown here. Amyloid deposition preferentially affects glomeruli in most cases, but interstitial or vascular involvement also Fig. Not only may amyloid involve the ally acellular but may elicit a giant cell reaction. Glomerular amyloid glomerular tuft, but parallel arrays of fibrils may extend through the usually forms first within the mesangium and may resemble diabetic basement membranes and form long delicate spike-like formations. This example shows the ity of the glomerulus will decrease as tuft obliteration occurs sensitivity of silver stain in demonstrating minute quantities of amyloid when it forms argyrophilic spicular arrays (arrows).

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The reasons for using albumin replacement include preventing paracentesis-induced circulatory dysfunction discount 150mg viagra extra dosage mastercard, minimizing electrolyte disturbances order on line viagra extra dosage, minimizing the nutritional impact of albumin loss generic 120mg viagra extra dosage free shipping, and preventing renal impairment. Current recommendations are that patients with drainage volumes less than 5 L do not need albumin replacement, and for larger volume paracentesis 6 to 8 g albumin/L may be considered. Infections of ascitic fluid are sufficiently common that the American Association for the Study of Liver Diseases recommends paracentesis for all hospitalized patients with ascites. Because cell counts are available more quickly than culture results, the decision to treat is made empirically on that basis. In cirrhosis, increases in portal pressure result from distorted hepatic architecture left in the wake of inflammatory insults. Fibrosis and 3276 regenerative nodules cause impedance to splanchnic flow through the liver and lead to formation of portosystemic collaterals, particularly with the gastric and esophageal venous systems. Progression of portal hypertension leads to increased local production of nitric oxide and, eventually, massive splanchnic vasodilation. Thus, portal hypertension becomes a problem not only of impedance to flow but also of a massive increase in flow to the liver. Rupture of the high-pressure collaterals that are formed is a highly lethal and feared complication of portal hypertension. Presence of varices correlates with the severity of the underlying liver disease, with incidence increasing from 40% in Child’s A patients to 85% in Child’s C patients. There is1 2 no evidence that they prevent formation of varices; however, they are effective as primary prophylaxis for variceal bleeding. For those patients who cannot tolerate β-blockers or in whom they are contraindicated, another option for primary prophylaxis of variceal bleeding is endoscopic ligation. Although the temptation to vigorously volume resuscitate and completely correct all coagulation abnormalities can be overwhelming in this setting, it should be resisted. Because bleeding is, to some extent, a pressure-related phenomenon, aggressive volume replacement may lead to resistant or recurrent bleeding. Medications to reduce portal pressure include vasopressin and its analogues and somatostatin and its analogues. Although β-blockers can reduce portal 3277 pressures, their effect on systemic pressures makes them undesirable in this setting. Early endoscopic variceal ligation in combination with pharmacotherapy is the preferred treatment for acute variceal bleed. Resistant or early recurrent variceal bleeding occurs in about 10% to 20% of patients. If bacteria are present in bile, the patient is at risk for infectious complications such as ascending cholangitis, hepatic abscess, and sepsis as well. Cholestasis and hyperbilirubinemia are associated with an increased incidence of acute kidney injury. This may be mediated by endotoxemia, as the result of both sepsis and loss of bile salts to the vascular space. Bile salts are normally secreted into the intestine where they prevent bacterial overgrowth and bind endotoxin, thereby preventing its absorption into the portal circulation. Loss of intestinal bile salts because of biliary obstruction may cause portal and systemic endotoxemia, leading to kidney injury. Kidney injury may additionally be exacerbated by the induced diuresis, as well as impairment of myocardial contractility, resulting from elevated serum levels of bile salts. The typical disease 3278 course is one of steady progressive loss of small bile ducts together with increasing fibrosis, leading to cirrhosis over the course of 10 to 20 years. Ursodeoxycholic acid, which may have immunomodulatory effects, is the only drug demonstrated to retard progression of the disease and offer survival benefit. Liver transplantation is the most definitive therapy, but is associated with a recurrence rate of 10% to 35%. It is also associated with other autoimmune diseases, such as insulin-dependent diabetes and psoriasis. Within the United States, it is the fifth most common cancer in men and the seventh in women. Ideally this should be in the form of liver ultrasonography every 6 months, with the use of α-fetoprotein only if ultrasound is not available. The Milan criteria (one tumor <5 cm or three tumors all <3 cm) define those patients, and those patients who meet the criteria and are transplanted have 5-year survival rates of 65% to 78% compared to 5-year survival of 68% to 87% for nontumor indications. In addition, some centers use these therapies to maintain transplant eligibility for patients on the waiting list. In fact it is often referred to as the hepatic manifestation of the metabolic syndrome. For those patients who are unable to lose weight by more conservative means, bariatric surgery has been shown to result in dramatic histologic and chemical improvement, with decreased steatosis/inflammation on biopsy and decreases in serum aminotransferases. Prior episodes of jaundice, particularly in relationship to surgical procedures and anesthesia, should be thoroughly investigated. Alcohol consumption, use of recreational or illicit drugs, medications (including herbal products), presence of tattoos, sexual promiscuity, consumption of raw seafood, and a history of travel to areas in which hepatitis is endemic should be sought. Symptoms of fatigue, anorexia, weight loss, nausea, vomiting, easy bruising, pruritus, dark-colored urine, biliary colic, abdominal distention, and gastrointestinal bleeding warrant further investigation for the presence of liver disease. Physical examination findings suggestive of active liver disease include icterus, palmar erythema, spider angiomas, gynecomastia, 3281 hepatosplenomegaly, ascites, testicular atrophy, petechiae, ecchymoses, and asterixis. In the absence of findings suggestive of liver disease, routine laboratory tests to assess hepatocellular integrity and hepatic synthetic function are not warranted. Routine laboratory testing may yield false-positive results, and true-positive results are infrequent in asymptomatic patients. As a result, minor elevations of liver-enzyme results—those less than twice the normal range—may be of no clinical importance. Nonetheless, in the presence of abnormal results (in an asymptomatic patient) the safest approach is to repeat the results; in the absence of elevations greater than twice the upper limits of normal it is reasonable to proceed with surgery. Medications include selected antibiotics, antiepileptic drugs, lipid-lowering agents, nonsteroidal anti-inflammatory agents, and sulfonylureas. Herbal medications and drugs of abuse are also associated with liver-enzyme abnormalities. Based on retrospective, small case series from the 1960s and 1970s, acute hepatitis confers a prohibitive risk for elective surgery. In a series of 36 patients with undiagnosed hepatitis who underwent laparotomy (for suspected biliary obstruction or hepatic malignancy) nearly one-third died. The majority of patients suffered complications that included bacterial peritonitis, wound dehiscence, and hepatic failure. In the absence of accumulating evidence, consensus opinion is that elective surgery should be postponed in patients with acute hepatitis. A number of studies have investigated the risk of surgery in patients with cirrhosis. They identified five factors—albumin, bilirubin, ascites, encephalopathy, and nutritional status—as important prognostic factors for patients with cirrhosis.

This improves the A nerve hook is then used to generate a plane between the surgical efciency and provides a more certain removal of inner dural layer and the tumor/pituitary gland surface order viagra extra dosage 120mg free shipping. The operative microscope can be adjusted to partially Closure visualize the medial wall of the cavernous sinus bilaterally viagra extra dosage 130mg discount. In the presence of a small hole in the be delivered into the surgical feld via either injection of diaphragm sellae purchase generic viagra extra dosage pills, the sella is packed with an abdominal fat 10 mL of air or saline through a lumbar drain, by a Valsalva graft. The sella is then reconstructed with either the bony maneuver, or by jugular vein compression. How- autologous bone or cartilage is unavailable, a bioabsorbable 22 Microscopic versus Endoscopic Transsphenoidal Pituitary Surgery 233 plate must be used to reconstruct the anterior sellar wall. The primary ported the results of 219 female patients who underwent mi- diference is that after an endoscopic technique the defect is crosurgical resection of prolactinomas. Not only is the bony anterior sphenoidotomy larger patients treated between 1976 and 1979 and those treated in all directions, unlike the microscopic transseptal ap- between 1998 and 1992 to assess the role of surgery before proach, but also the nasal mucosa overlying the sphenoid (group 1) and during (group 2) the era of dopamine agonist is completely removed during the approach. Also because a speculum is not used, the adenomas and between 80 and 88% of patients with either fat graft can be more difcult to place during an endoscopic intrasellar or suprasellar macroadenomas displayed initial approach. The authors reported a 82% continued remission rate with a median follow-up I Microscopic Versus Endoscopic Surgical of 15. With regard to Cushing’s disease, Pouratian et al31 re- The microscopic transsphenoidal approach has been the most common technique for resecting pituitary lesions ported the outcomes in 111 patients with the diagnosis of over the past 40 years. Consequently, the majority of large Cushing’s disease without postoperative pathologic con- surgical series include patients with tumors primarily re- frmation. In addition, many of the older se- a drop in serum cortisol levels to 2 µg/mL or lower within ries do not diferentiate among those patients treated via 72 hours of surgery. The authors reported that 50% of the microscopic, endoscopic-assisted, or pure endoscopic patients achieved postoperative remission as compared approach. Over the past 10 years, larger case series have with 79% for the 490 total transsphenoidal operations been published reporting the surgical results using the pure for Cushing’s disease performed by this chapter’s senior endoscopic approach alone. Of the specimens, 161 contained tumor Microscopic Approach cell invasion and 192 displayed no evidence of invasion. In Laws and Jane21 reported their series of 4020 transsphe- addition, 291 specimens were from primary transsphenoidal noidal operations in which the majority of cases used the resection and 55 specimens were from repeat transsphenoi- microscope approach alone. The neuropathologist identifed dural invasion nonfunctioning adenomas and preoperative visual loss, 87% in 41% of the former group and in 69% in the latter group. Requirements for remis- dural invasion was noted in 50% of nonsecretory tumors sion included normalization of insulin-like growth factor-1 and in 30 to 35% of the secretory tumors. Acromegalic symptoms were improved undergoing primary tumor resection as compared with pa- in 95% of patents with a 10-year recurrence risk of only 2%. Finally, the authors pared with traditional craniotomy approaches, the results reported a 76. In comparing the microscopic versus the endoscopic approach, epistaxis decreased from 1. Over the past 10 years, reports detail- Endoscopic Approach ing the surgical outcomes following the endoscopic resec- tion of pituitary adenomas have emerged. These reports In assessing any surgical lesion, the surgeon must always have subsequently allowed for a comparison between the consider what surgical approach can best be utilized to max- microscopic and endoscopic techniques. As reported by Ciric et al,39 the surgeon’s experi- tients treated via a pure endoscopic approach. The operative microscope is a standard part of also compared complication rates to the rates reported by many neurosurgical operations from spinal to intracranial Ciric et al,39 generated via a national survey evaluating sur- procedures. Consequently, most neurosurgeons are familiar geons using a transseptal-transsphenoidal approach. For with how to manipulate the microscope to obtain an ideal nonsecretory adenomas, complete surgical resection was three-dimensional view. In addition, the microscope can confrmed via postoperative magnetic resonance imaging easily be positioned such that the manipulation of surgi- in 93% of cases using the pure endoscopic approach and in cal instruments is not impeded. An improved uses a nasal speculum, potentially allowing for decreased initial remission rate for secretory tumors was also seen injury to the nasal mucosa. The the microscopic transseptal versus the pure endoscopic ap- feld of view is narrow, restricting the view of anatomical proach, nasal septal perforations decreased from 6. Thus, this approach relies Frank et al40 also reported similar surgical outcomes in on such adjuncts as intraoperative fuoroscopy to assist with comparing the pure endoscopic approach versus the micro- the approach to the sella turcica. They also compared their surgical results limits the surgical view by line of sight. With regard to tu- 22 Microscopic versus Endoscopic Transsphenoidal Pituitary Surgery 235 mor resection, the sellar foor and cavernous sinus walls are Second, the assistant driving the endoscope must be con- rarely fully visible. The optic chiasm is also rarely visible, stantly aware of the endoscope’s position so that it does not limiting direct confrmation that it is adequately decom- interfere with the surgical instruments and does not rotate, pressed. Finally, the transseptal microscopic approach typi- providing incorrect information regarding the anatomical cally requires postoperative nasal packing. Finally, and as a corollary to this second issue, Compared with the microscopic technique, the endo- the surgeon must maximize the exposure of the sella turcica scopic approach ofers unique advantages to the surgeon. Consequently, the binasal endoscopic sight, the endoscope provides a panoramic view to identify exposure is larger than the microscopic exposure. The endoscope allows for a superior view of the nasal anatomy for identifcation of the sphenoid sinus. Consequently, fuoroscopic guidance is not I Conclusion necessary for safely reaching the sphenoid ostia. Once in- side the sphenoid sinus, the limits of the sella turcica can be The transsphenoidal resection of pituitary lesions has a rich accurately determined via identifcation of such anatomical history that dates to the beginning of the 20th century. The landmarks as the carotid protuberance and the opticoca- surgical approach has continually evolved over this time pe- rotid recess. The contributors to this evolution have all based their chal sphenoid sinus in which image guidance is still helpful. These goals include With regard to tumor resection, the endoscope provides a maximizing surgical resection of the lesion while minimizing magnifed view of the tumor–gland interface. As the neurosurgeon gains experi- tion of this interface can potentially lead to improvement in ence with any modifcation to the surgical approach, compli- both the degree of tumor resection as well as preservation cations will continue to decrease as surgical outcomes equal of normal pituitary gland function. In addition, the 0- and and perhaps surpass those achieved by previous techniques. As neurosurgeons gain experience with the requires nasal packing, which has been shown to correlate latter technique, surgical outcomes can be more accurately with improved patient comfort and satisfaction. The contribution of Davide Although the endoscopic approach ofers many advan- Giordano (1864–1954) to pituitary surgery: the transglabellar-nasal tages, it also has disadvantages. Neurosurgery 1998;42:909–911, discussion 911–912 not familiar with the endoscope, and a steep learning curve 2.