Paul David Sponseller, M.D.

• Chief, Division of Pediatric Orthopaedics
• Professor of Orthopaedic Surgery

https://www.hopkinsmedicine.org/profiles/results/directory/profile/0004804/paul-sponseller

Another technique of mechanical limitation of blood flow to the nonventilated lung is the inflation of a pulmonary artery catheter balloon in the main pulmonary artery of the operative lung erectile dysfunction viagra not working generic levitra extra dosage 40mg overnight delivery. This has been shown to be a useful technique for resection of large pulmonary arteriovenous fistulas impotent rage man 100mg levitra extra dosage fast delivery. It is also recommended when patients have known or suspected cardiovascular disease that may impact outcomes xylitol erectile dysfunction generic levitra extra dosage 100mg online. It is often difficult for the surgeon to assess this during thoracotomy or sternotomy impotence remedies order generic levitra extra dosage on-line. Options for local anesthesia include topical anesthesia via a nebulizer impotence in men order levitra extra dosage 60 mg line, handheld aerosol erectile dysfunction young male causes order levitra extra dosage 60 mg on line, or soaked pledgets; nerve blocks (laryngeal and/ or glossopharyngeal nerves); direct administration of local anesthetic through the bronchoscope (spray-as-you-go technique),100 with or without sedation or opioid or antisialagogues. Options during general anesthesia include spontaneous versus positive pressure ventilation with or without muscle relaxation. A swivel bronchoscopy connector with a self-sealing valve is used to facilitate the ventilation and manipulation of the bronchoscope at the same time inhalation and/or intravenous agents can be used for anesthesia. Patients who have copious secretions in the preoperative period should receive anticholinergic medication to ensure a dry field, which provides optimal visualization. This is particularly useful in the patient with a difficult airway when maintaining spontaneous respiration may be the safest method of anesthetic management. Rigid bronchoscopy has traditionally been considered the technique of choice for the preoperative diagnostic assessment of an airway obstruction involving the trachea and in the therapy of massive hemoptysis and foreign bodies in the airway. The role of interventional bronchoscopy with laser, bronchial dilation, or stent insertion is well established for the treatment of malignant and benign central airway and endobronchial lesions. Patients undergoing rigid bronchoscopy should have a complete preoperative evaluation, including radiologic studies. If time permits, it is recommended that patients with severe stridor receive pharmacologic interventions for temporary stabilization of the condition. Treatments may include inspired cool saline mist, nebulized racemic epinephrine, and the use of systemic steroids. The addition of topical anesthesia or nerve blocks to the airway decreases the tendency to breath-hold and cough when volatile anesthetics are used. This requires thorough preoxygenation, and the anesthesiologist will have to interrupt surgery to ventilate the patient before desaturation occurs. This should allow the surgeon working intervals of 3 minutes or longer, depending on the underlying condition of the patient. This allows the use of a standard anesthetic circuit but may cause significant air leaks if there is a discrepancy between the size of a smaller bronchoscope and a larger airway. This can be performed with a handheld injector such as the Sanders injector104 or with a high-frequency ventilator. These techniques are most useful with intravenous anesthesia because they entrain gas from either the room air or an attached anesthetic circuit, and the dose of any volatile agent delivered will not be known. The use of anticholinergic agents before manipulation of the airway will decrease secretions during the bronchoscopic examination. For a patient undergoing rigid bronchoscopy, the surgeon must be at the bedside for the induction of anesthesia and be prepared to establish airway control with the rigid bronchoscope. In adults, intravenous anesthesia and the use of muscle relaxants is more common with ventilation by a combination of methods 3 and 4. Non-depolarizing relaxants may be needed for prolonged procedures such as stent placement or tumor resection. Remifentanil and propofol infusions can be administered if an intravenous regimen is the planned anesthetic. However, there is a higher potential for accidental reflected laser strikes and there is more delayed airway edema. If excessive leak of tidal volume occurs around the bronchoscope with positive pressure ventilation, it may be necessary to place throat packs to facilitate ventilation. Continuous communication with the surgeon or pulmonologist is necessary in case desaturation occurs. For patients with underlying cardiac disease, an arterial catheter is usually placed for rigid bronchoscopy to facilitate rapid hemodynamic control. For prolonged procedures, it is useful to perform repeated arterial blood gas analysis to confirm the adequacy of ventilation. It is always best to defer rigid bronchoscopy to decrease the aspiration risk, if possible, in these patients. When there is no benefit to be gained by deferring and/or the airway risk is acute (eg, aspiration of an obstructing foreign body), each case must be managed on an individual basis depending on the context and competing risks. Other rigid bronchoscopic procedures that require anesthesia include dilation for benign airway stenosis, core-out of malignant lesions in the trachea, laser ablation of endobronchial and carinal tumors, and therapeutic bronchoscopic interventions before surgical resection of lung cancer. In addition, interventional bronchoscopy is often used for the management of airway complications following lung transplantation. In some situations, it may be necessary to keep the patient intubated with a small (ie, 6. These patients may require the use of steroids, nebulized racemic epinephrine, or helium/oxygen mixtures to treat stridor in the postoperative period. Anesthesia for Tracheal Resection Tracheal resection and reconstruction is indicated in patients who have a tracheal obstruction as a result of a tracheal tumor, previous tracheal trauma (most commonly, postintubation stenosis), congenital anomalies, vascular lesions, and tracheomalacia. For patients who have operable tumors, approximately 80% undergo segmental resection with primary anastomosis, 10% undergo segmental resection with prosthetic reconstruction, and the remaining 10% undergo placement of a Montgomery T-tube stent. Bronchoscopy for a patient with tracheal stenosis should be carried out in the operating room where the surgical and anesthesia teams are present and ready to intervene should loss of airway occur. An advantage of rigid bronchoscopy over flexible bronchoscopy is that it can bypass the obstruction and provide a ventilation pathway if complete obstruction occurs. During surgery, all patients should have an invasive arterial catheter placed to facilitate measurement of arterial blood gases, as well as measure arterial blood pressure. Induction of anesthesia in patients with a compromised airway requires good communication between the surgical team and the anesthesiologist. The surgeon should always be in the operating room during induction and available to manage a surgical airway if this becomes necessary. The airways of patients with congenital or acquired tracheal stenosis are unlikely to collapse during induction of anesthesia. However, intratracheal masses may lead to airway obstruction with induction of anesthesia and should be managed similarly to anterior mediastinal masses (see "Mediastinal Masses"). Ventilation is via a sterile anesthetic circuit passed across the drapes into the surgical field. With a low tracheal lesion, a right thoracotomy provides the optimal surgical exposure. After the tracheal resection is completed, most patients are kept in a position of neck flexion to reduce tension on the suture line. A thick chin-sternum suture may be placed for several days to maintain neck flexion, or a cervical splint may be used. One of the complications in the postoperative period is tetraplegia, with hyperflexion of the neck having been implicated as a potential cause. Posttracheostomy Hemorrhage Hemorrhage in the immediate postoperative period following a tracheostomy is usually from local vessels in the incision such as the anterior jugular or inferior thyroid veins. Massive hemorrhage 1 to 6 weeks postoperatively is most commonly due to trachea-innominate artery fistula. The management protocol for trachea-innominate artery fistula is outlined in Box 49. Mediastinal Masses Patients with mediastinal masses, particularly masses in the anterior and/or superior mediastinum, present unique problems for the anesthesiologist. Tumors of the mediastinum include thymoma, teratoma, lymphoma, cystic hygroma, bronchogenic cyst, and thyroid tumors. Mediastinal masses may cause obstruction of major airways, pulmonary arteries, atria, and/or the superior vena cava. During induction of general anesthesia in patients with an anterior or superior mediastinal mass, airway obstruction is the most common and feared complication. A history of supine dyspnea or cough should alert the clinician to the possibility of airway obstruction upon induction of anesthesia. The other major complication is cardiovascular collapse secondary to compression of the heart or major vessels. These deaths may be the result of the more compressible cartilaginous structure of the airway in children or because of the difficulty in obtaining a history of positional symptoms. First, reduced lung volume occurs during general anesthesia, and tracheobronchial diameters decrease according to lung volume. Second, bronchial smooth muscle relaxes during general anesthesia, allowing greater compressibility of large airways. Third, paralysis eliminates the caudal movement of the diaphragm seen during spontaneous ventilation. This eliminates the normal transpleural pressure gradient that dilates the airways during inspiration and minimizes the effects of extrinsic intrathoracic airway compression. Patients with uncertain distal airways should have diagnostic procedures performed under local or regional anesthesia whenever possible. Patients with uncertain airways requiring general anesthesia need a step-by-step induction of anesthesia with continuous monitoring of gas exchange and hemodynamics. If muscle relaxants are required, ventilation should first be gradually taken over manually to ensure that positive-pressure ventilation is possible and only then can a short-acting muscle relaxant be administered (Box 49. Development of airway or vascular compression upon anesthetic induction requires that the patient be awakened as rapidly as possible and then other options for the procedure be explored. Intraoperative life-threatening airway compression usually has responded to one of two therapies: either repositioning of the patient (it must be determined before induction if there is a position that causes less compression and fewer symptoms) or rigid bronchoscopy and ventilation distal to the obstruction (this means that an experienced bronchoscopist and equipment must be immediately available in the operating room). The rigid bronchoscope, even if passed into only one mainstem bronchus, can be used for oxygenation during resuscitation. In virtually all adults with a mediastinal mass, diagnostic procedures and imaging can be performed, if necessary, without subjecting the patient to the risks of general anesthesia. An extrathoracic source of tissue for diagnostic biopsy (pleural effusion or extrathoracic lymph node) should be sought as an initial measure in every patient. Regardless of the proposed diagnostic or therapeutic procedure, the flat (supine) position is never mandatory. With improved awareness of the risk of acute intraoperative airway obstruction in these patients, life-threatening events are now less likely to occur in the operating room. In adults, acute airway obstruction is now more likely to occur postoperatively, in the recovery room. As with all other lower airway abnormalities, airway management requires a flexible plan and full understanding of the anatomy by the S Vascular Anomalies With Airway Compression A spectrum of congenital vascular abnormalities can cause tracheal, bronchial, and/or esophageal compression. These abnormalities include double aortic arch, right aortic arch with anomalous origin of the left subclavian artery, left aortic arch with anomalous right subclavian, and Kommerell diverticulum. In combination with the ligamentum arteriosum or a patent ductus, it may cause a complete vascular ring compressing the trachea. Symptoms involve varying degrees of esophageal or airway obstruction and may present at any age. There is a tendency for airway symptoms to predominate in children and esophageal symptoms to predominate in adults. Respiratory symptoms and simple bronchoscopy can lead to a misdiagnosis of congenital tracheal stenosis. A rigid bronchoscope should be available in the operating room during induction and emergence from anesthesia in case of distal airway collapse. Consideration should be given to the use of corticosteroids to potentially decrease airway edema postoperatively. There is the potential for postoperative tracheomalacia in patients who have had severe airway compression. Impact of preoperative statin therapy on adverse postoperative outcomes in patients undergoing vascular surgery. Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition). Anesthetic-induced improvement of the inflammatory response to one-lung ventilation. Assessing the diagnostic accuracy of pulse pressure variations for the prediction of fluid responsiveness: a "gray zone" approach. Prediction of volume responsiveness during one-lung ventilation: a comparison of static, volumetric and dynamic parameters of cardiac preload. Anesthetic considerations for thoracoscopic sympathetic ganglionectomy to treat ventricular tachycardia. Management of pulmonary hypertension: physiological and pharmacological considerations for anesthesiologists. Severe pulmonary hypertension complicates postoperative outcome of non-cardiac surgery. Superiority of desflurane over sevoflurane and isoflurane in the presence of pressure-overload right ventricular hypertrophy in rats. Role of ketamine in the management of pulmonary hypertension and right ventricular failure. Use of vasopressin after Caesarean section in idiopathic pulmonary arterial hypertension. Inhaled nitric oxide versus prostacyclin in chronic shunt-induced pulmonary hypertension. The successful management of severe protamine-induced pulmonary hypertension using inhaled prostacyclin. Accuracy of Doppler echocardiography in the hemodynamic assessment of pulmonary hypertension. A prospective, multi-center, observational cohort study of analgesia and outcome after pneumonectomy. Con: a bronchial blocker in not a substitute for a double-lumen endobronchial tube. Airway injuries after one-lung ventilation: a comparison between double-lumen tubes and endobronchial blocker.

They identified patients as being at risk if they presented with any of the following conditions: occult coronary artery disease erectile dysfunction female doctor order 100mg levitra extra dosage with visa, significant preexisting atherosclerosis erectile dysfunction reversible purchase levitra extra dosage in united states online, chronic arterial hypertension cannabis causes erectile dysfunction discount levitra extra dosage 60 mg overnight delivery, and chronic organ insufficiency impotence 28 years old order levitra extra dosage in united states online. More than 150 basic science and clinical investigations that directly compared pulsatile and nonpulsatile perfusion have been published erectile dysfunction frustration levitra extra dosage 60mg overnight delivery. Although there is an extensive body of literature erectile dysfunction bob buy levitra extra dosage discount, there remains uncertainty about the effects of pulsatile perfusion on clinical outcomes. In a similar study, Azariades and associates505 questioned the benefits of pulsatile flow on the stressrelated release of cortisol and were unable to show any differences between patients treated with either pulsatile or nonpulsatile flow. There were no differences in endotoxin levels, complement fragments, or granulocyte elastase between nonpulsatile or pulsatile perfusion groups at any time. Besides not having an oxygenator, the circuit contains neither a cardiotomy reservoir nor a venous reservoir, so that fluids cannot be added to the circuit. Left atrial cannula size varies, but in most adult patients, the typical single cannula ranges from 32 Fr to 40 Fr. Alternate cannula locations for draining blood from the heart involve the ascending aorta or the left ventricular apex. Blood is returned to the patient via isolation of the femoral artery by cutdown technique, with retrograde flow into the abdominal aorta. The typical cannula sizes used for femoral artery cannulation range from 16 Fr to 22 Fr. Alternate cannulation sites for the return of blood include the descending thoracic aorta. The risk for perioperative bleeding is high because of the combined use of prosthetic graft materials and large anastomotic sites. The use of heparin-bonded circuits in these patients may offer distinct benefits in reducing bleeding associated with systemic heparinization. When the upper body circulation is isolated from the lower body circulation by the placement of vascular clamps, the two circulations are separated and pulsatile flow is lost in the lower body. At the time of aortic clamping, the proximal aortic pressure increases precipitously as a result of the dramatic change in afterload. Filling pressures, measured with a pulmonary artery catheter or left atrial catheter, usually decline by approximately 50%. Once these flow parameters have stabilized, any alteration in hemodynamics should be adjusted either by pharmacologic control or by fluid replacement. Drugs used most often to treat the initial hypertension are nitroprusside, nitroglycerin, and inhalation agents. Other commonly used drugs are phenylephrine, epinephrine, dobutamine, and dopamine. Methods of volume replacement during repair of thoracic aortic aneurysms must be considered carefully before the start of the case because the potential for rapid blood loss is high. Cerebral Protection During Circulatory Arrest As mentioned in the previous section, aneurysms of the descending thoracic and abdominal aorta represent a major challenge to the anesthesiologist, surgeon, and perfusionist in developing plans for patient management. The next three sections review some of the specific practices involved in managing a patient with these challenging lesions. This technique also has been efficacious in treating various other critical disease processes, including neurologic lesions and renal cell carcinoma. Furthermore, brain oxygen extraction increased as perfusion flow declined, which was unlike other tissue beds in the body. Other temperatures that can be measured include esophageal, nasopharyngeal, tympanic, and skin temperature. Both tympanic and nasopharyngeal temperatures are remeasured to reflect brain temperatures. The depth of cooling remains controversial, with most clinicians choosing to monitor electroencephalographic activity. Some authors advocate monitoring jugular venous bulb oxygen saturation and terminating perfusion only after the saturation is greater than 95%. In general, the limit of safe circulatory arrest time in adult patients undergoing profound hypothermia is between 40 and 50 minutes. Use of vasodilators to facilitate distal perfusion is warranted and treatment of metabolic acidosis should proceed vigorously. This mild hypothermia provides additional cerebral protection in the early postoperative period. The use of barbiturates in providing added cerebral protection has not been clearly defined, and their benefits in cardiac surgery may be related to their early use at the onset of surgery. Flow rates to the brain are controlled between 5 and 10 mL/kg/minute, with a perfusion pressure at the circuit kept under 150 mm Hg. This is not of major concern because of the anatomic nature of the circle of Willis and distribution of cerebral blood flow. The improved safety resulting from technologic enhancements to pressure control modules and air detection systems of heart-lung machines makes these arguments moot. Monitoring of jugular bulb oxygen saturations or cerebral oxygenation with near-infrared spectroscopy provides feedback information that is used to adjust flow rates and delivery pressures so that adequate delivery of oxygen is matched with extraction rates. Most human errors emanate from three specific failures: a failure of perception (things are not as they appear), a failure of assumption (the 10-mL vial in the middle drawer with a blue label is always heparin), and a failure in communication. It is always possible for an individual to fail; however, through teamwork and communication, a system can be designed that is highly reliable in which potential errors are mitigated through situational awareness and communication. Clinicians are prone to assume that aspects of the working environment are reliable. In highly functional teams, the members have an expectation that there will be failure and are constantly observing and questioning. Analysis of 2455 recent sentinel events reported to the Joint Commission for Hospital Accreditation showed that the primary root cause in more than 70% was communication failure, and approximately 75% of these patients died of their injuries. The checklist has been tested in eight cities around the world and resulted in a reduction of mortality from 1. Checklists also should be used to improve reliability of infrequent tasks or unexpected occurrences. Checklists help clinicians perform simple tasks reliably and allow more cognitive engagement for the things that are complicated and complex. It is important to see variation as an opportunity to improve and to diminish the likelihood of errors. Gladwell566 described a pathologic type of communication that he referred to as "mitigated speech. This occurs when an individual experiences a problem but there is a reluctance to speak up about it, when trying to be polite, when ashamed or embarrassed, or when being deferential to authority. The key to breaking this pattern of flawed communication is for leaders to understand that their number-one job is to get the best performance possible out of their team, acknowledge their own fallibility, and let those who work on the team know that they are expected to speak up about anything unusual or anything that is of concern. More commonly, communication may be difficult because of an abrasive or difficult team member whose behavior exasperates staff. Recipients of this type of behavior can be at a loss for words to respond to this type of abuse. The danger is that communication may be avoided with difficult individuals because it is too painful and frightening to engage such an individual. Frankel567 has described the "Five Cs," a pattern for responding to individuals who exhibit this type of abusive behavior. The scripted responses to this abuse are designed in a way that one learns to escalate until the pattern is broken. Furthermore, 88% of surgeons thought there was good collaboration between surgeons and nurses, whereas only 48% of nurses considered surgeons good collaborators with nurses. Comparative database reports were produced in 2007 and 2008 and will be produced yearly through at least 2012. The areas surveyed that appeared to be opportunities for improvement include development of a nonpunitive response to error, handoffs and transitions, and the number of events reported. These surveys are valuable in that they identify areas where there is an opportunity to improve. The survey results can be used as a tool to help leaders to become knowledgeable about the culture within units and professional groups and lead to the development of training and exercises to improve the safety culture. It may be easily configured to simulate a number of routine and nonroutine scenarios (Box 32. In the educational setting, a simulator provides a standardized experience and evaluation process for students. Students or experienced perfusionists may be subjected to a particularly challenging clinical problem over and over again, and their response to the clinical problem can be accurately evaluated. The authors believe that these systems will supplant recertification requirements based on completing an actual number of clinical cases with periodic required simulation examinations (see Chapter 17). A survey of 314 perfusionists from centers in the Northeastern region of the United States in 2002 revealed that 97% of the perfusionists surveyed believed that such practice drills would be beneficial; however, only 17% reported that such drills are conducted at their centers. Great strides have been made in conserving blood and reducing transfusions, attenuation of the systemic inflammatory response, and organ protection. Perfusion devices will continue to improve with the introduction of improved design and the introduction of improved gas exchange surfaces and biocompatible surface coatings. The use of computer technology, human factors, science, and simulation training will improve the operator-machine interface and the nontechnical skills of teams, further enhancing safety and improving patient outcomes. Artificial maintenance of circulation during experimental occlusion of pulmonary artery. Laboratory work preceding the first clinical application of cardiopulmonary bypass. Comparing off-pump and on-pump clinical outcomes and costs for diabetic cardiac surgery patients. A meta-analysis of randomized trials for repeat revascularization following off-pump versus on-pump coronary artery bypass grafting. Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease. Roller pump induced tubing wear: Another argument in favor of arterial line filtration. Progress in the design of a centrifugal cardiac assist pump with transcutaneous energy transmission by magnetic coupling. Extracorporeal membrane oxygenation using a centrifugal pump and a Servo regulator to prevent negative pressure. The effects of pressure and hemolysis caused by Biomedicus centrifugal pumps and roller pumps. Beware centrifugal pumps: Not a one-way street, but a potentially dangerous "siphon" [Letter]. In vitro comparison of the blood handling by the constrained vortex and twin roller pumps. The effects of pressure and flow on hemolysis caused by biomedicus centrifugal pumps and roller pumps. Proinflammatory mediator response to coronary bypass surgery using a centrifugal or a roller pump. The effect of extracorporeal circulation time and patient age on platelet retention during cardiopulmonary bypass: A comparison of roller and centrifugal pumps. Serum S100 beta release after coronary artery bypass grafting: Roller versus centrifugal pump. A comparison of the benefits of roller pump versus constrained vortex pump in adult open-heart operations utilizing outcomes research. Centrifugal versus roller head pumps for cardiopulmonary bypass: Effect on early neuropsychologic outcomes after coronary artery surgery. Centrifugal pumping: the patient outcome benefits following coronary artery bypass surgery. Reduced release of tissue factor by application of a centrifugal pump during cardiopulmonary bypass. Inflammatory response to cardiopulmonary bypass using roller or centrifugal pumps. Centrifugal pump and roller pump in adult cardiac surgery: a meta-analysis of randomized controlled trials. Perioperative blood transfusion and blood conservation in cardiac surgery: the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists clinical practice guideline. Calculation of certain indices of cardiopulmonary function using a digital computer. Experimental and clinical use of an automated perfusion system and a membrane oxygenator. Electronic data processing: the pathway to automated quality control of cardiopulmonary bypass. Continuous quality improvement of perfusion practice: the role of electronic data collection and statistical control charts. Medicare and Medicaid Programs; Electronic Health Record Incentive Program; Final Rule.

Development of regional myocardial ischemia distal to a critical coronary stenosis during cardiopulmonary bypass: comparison of the fibrillating vs erectile dysfunction venous leak buy levitra extra dosage american express. Metabolic measurements in the human heart-lung preparation during hypothermic cardioplegia erectile dysfunction drugs cialis buy levitra extra dosage 60 mg on-line. Relationship of whole body oxygen consumption to perfusion flow rate during hypothermic cardiopulmonary bypass impotence when trying for a baby purchase levitra extra dosage. Safe limit of hemodilution in cardiopulmonary bypass -comparative analysis between cyanotic and acyanotic congenital heart disease erectile dysfunction treatment herbal cheap 100mg levitra extra dosage with mastercard. Oxygen transport to tissue under normovolemic moderate and extreme hemodilution during coronary bypass operation impotence exercise levitra extra dosage 60 mg generic. Theoretical analysis of cerebral venous blood hemoglobin oxygen saturation as an index of cerebral oxygenation during hypothermic cardiopulmonary bypass erectile dysfunction age 33 buy cheap levitra extra dosage. Role of perfusion pressure and flow in major organ dysfunction after cardiopulmonary bypass. Cerebrovascular and cerebral metabolic effects of alterations in perfusion flow rate during hypothermic cardiopulmonary bypass in man. Low-flow cardiopulmonary bypass: importance of blood pressure in maintaining cerebral blood flow. Cerebral blood flow is determined by arterial pressure and not cardiopulmonary bypass flow rate. Cerebral blood flow during low-flow hypothermic cardiopulmonary bypass in baboons. Monitoring oxygenator expiratory isoflurane concentrations and the bispectral index to guide isoflurane requirements during cardiopulmonary bypass. Hypothermia after cardiopulmonary bypass in man: amelioration by nitroprusside-induced vasodilation during rewarming. Postoperative hyperthermia following off-pump versus on-pump coronary artery bypass surgery. Changes in body temperature following cardiopulmonary bypass procedures; the effects of active rewarming. Effect of heated humidified gases on temperature drop after cardiopulmonary bypass. A comparison of radial, brachial, and aortic pressures after cardiopulmonary bypass. Transesophageal echocardiography for definition of incidence and monitoring removal by improved techniques. What is the optimal device for carbon dioxide deairing of the cardiothoracic wound and how should it be positioned Energy dose and other variables possibly affecting ventricular defibrillation during cardiac surgery. Lidocaine for prevention of reperfusion ventricular fibrillation after release of aortic cross-clamping. Regional hemodynamics and oxygen supply during isovolemic hemodilution in the absence and presence of high-grade beta-adrenergic blockade. Hematocrit and blood volume control during cardiopulmonary bypass with the use of hemofiltration. Sodium bicarbonate in the treatment of subtypes of acute lactic acidosis: physiologic considerations. The effects of metabolic acidosis and alkalosis on the response to sympathomimetic drugs in dogs. Normal parathyroid hormone responses to hypocalcemia during cardiopulmonary bypass. Retrograde aortic dissection during cardiopulmonary bypass: "nonoperative" management. Recognition and management of ascending aortic dissection complicating cardiac surgical operations. Transesophageal echocardiographic diagnosis of aortic dissection during cardiac surgery. Unilateral cerebral oxygen desaturation during emergent repair of a DeBakey type 1 aortic dissection: potential aversion of a major catastrophe. Massive arterial air embolism due to rupture of pulsatile assist device: successful treatment in the hyperbaric chamber. Hyperbaric treatment of cerebral air embolism sustained during an open-heart surgical procedure. Hypothermia in conjunction with hyperbaric oxygenation in the treatment of massive air embolism during cardiopulmonary bypass. Cerebral air embolism occurring at angiography and diagnosed by computerized tomography. The effectiveness of venoarterial perfusion in treatment of arterial air embolism during cardiopulmonary bypass. Cardiac surgery with extracorporeal circulation during pregnancy; report of 3 cases. Tococardiography in pregnancy during extracorporeal bypass for mitral valve replacement. Reoperative aortic and mitral prosthetic valve replacement in the third trimester of pregnancy. Fetal Monitoring during cardiopulmonary bypass for removal of a left atrial myxoma during pregnancy. The effect of maternal hypothermic cardiopulmonary bypass on fetal lamb temperature, hemodynamics, oxygenation, and acid-base balance. The closure of interventricular septal defects in dogs during open cardiotomy with the maintenance of the cardiorespiratory functions by a pump-oxygenator. Partial cardiopulmonary bypass for core rewarming in profound accidental hypothermia. Accidental deep hypothermia with cardiopulmonary arrest: extracorporeal blood rewarming in 11 patients. Outcome of survivors of accidental deep hypothermia and circulatory arrest treated with extracorporeal blood warming. Cardiopulmonary bypass and hypothermic circulatory arrest for basilar artery aneurysm clipping. Hypothermia and cardiac arrest in the treatment of giant aneurysms of the cerebral circulation and hemangioblastoma of the medulla. Reappraisal of cardiopulmonary bypass with deep hypothermia and circulatory arrest for complex neurosurgical operations. Management of difficult intracranial aneurysms by deep hypothermia and elective cardiac arrest using cardiopulmonary bypass. Cardiopulmonary bypass, profound hypothermia, and circulatory arrest for neurosurgery. Deep hypothermic circulatory arrest for the management of complex anterior and posterior circulation aneurysms. Single and multivessel port-access coronary artery bypass grafting with cardioplegic arrest: technique and reproducibility. Port-access approach for cardiac surgical procedures: our experience in 776 patients. Effects of extracorporeal circulation upon behavior, personality, and brain function. Neurologic dysfunction following cardiac operation with low-flow, lowpressure cardiopulmonary bypass. Reduction of flow rate and arterial pressure at moderate hypothermia does not result in cerebral dysfunction. A prospective, randomized study of the effects of prostacyclin on neuropsychologic dysfunction after coronary artery operation. A randomized study of carbon dioxide management during hypothermic cardiopulmonary bypass. Effect of cerebral perfusion pressure during cardiopulmonary bypass on neuropsychiatric outcome following coronary artery bypass grafting. Failure to demonstrate relationship between mean arterial pressure during cardiopulmonary bypass and postoperative cognitive dysfunction. Presented at the Society of Cardiovascular Anesthesiologists, Montreal, p 211, 1994. The development of surgical interventions for the treatment of car- diovascular disease has resulted in enhancements in the quality of life for an indeterminate number of patients. Indeed, the sheer complexity of how blood behaves in an extravascular environment and the influence of synthetic materials on biologic processes have provided rich areas for research. The first reported successful use of the heart-lung machine was on May 6, 1953, when John H. Miller, "Near the termination of the operation, the machine suddenly shut down-reason being, clotting of the blood on the oxygenator took place, and the automatic arterial control sensed the sudden fall in the pool at the bottom and shut the entire machine down. However, his one successful case served to inspire others, including John Kirklin at the Mayo Clinic, C. The overall rate of graft patency was lower in the off-pump group than in the on-pump group as well (82. No attempt is made to chronicle or list the multitude of components and perfusion devices currently manufactured. Similarly, the techniques described under perfusion practices were chosen because of the current clinical interest, with specific protocols taken from referenced sources. Apositivedisplacement pump with a stationary raceway and rotating twin roller pumps. The pumping mechanism is also referred to as the pump head, and the tubing that traverses the raceway is referred to as the pump header. Both of these adaptations were important in reducing the mobility of tubing during the operation of the pump, which decreased the potential for tubing rupture in the pump head. This is displayed on a digital readout and is referred to as the output (flow) of the pump. A modern heart-lung machine consists of between Mechanical Devices Blood Pumps All extracorporeal flow occurs through processes that incorporate a transfer of energy from mechanical forces to a perfusate and, ultimately, to the tissue. Methods of achieving this transfer of energy include using gravitational and mechanical forces or a combination of the two. It is through the transfer of energy from an electrical power source to the motor of a pumping mechanism and on to the fluid (blood) that causes tissue perfusion. Most machines are modular in design, permitting the rapid change-out of a defective unit in the case of single-pump failure. It is standard practice of perfusionists to rotate the pumps along the base console in different positions so that mechanical wear is distributed evenly while maintaining equitable time utilization. Each pump is independently controlled by a rheostat that functions to regulate the rpm of the rollers. Each pump is calibrated according to specific flow constants that are calculated from the internal diameter of tubing, as well as the tubing length, placed in the pump raceway. For this reason, a single console can be used to perfuse a wide range of patients whose size may vary from a few kilograms to more than one hundred. This is accomplished simply by changing the raceway tubing and the shims that hold the tubing in place. The larger the internal diameter of the tubing, the lower the rpm necessary to achieve a desired pump flow. The magnitude of hemolysis is related to both the time and exposure of the blood to shear forces generated by the pump. This momentary negative pressure under certain conditions may induce the cavitation of air dissolved in the solution. A further related concern is particulate emboli that may be generated by microfragmentation, so-called spallation, of the inner surface of the tubing where the roller contacts the tubing and where the fold at the edges of the tubing occurs. The setting of occlusion in the pump head is extremely important and varies among the pumps used on the heart-lung machine console. The arterial pump head occlusion should be set by a waterdrop method that incorporates a "30-and-1" rule for setting occlusion. In this method, the occlusion of the arterial pump is set by displacing a column of water (perfusate) 30 cm above the highest water level in the venous or cardiotomy reservoir (whichever is highest) and allowing the perfusate to drop 1 cm/min. This ensures that during the time when cardioplegic solution is not delivered, or the left ventricular vent is turned off, the risk for negative pressure in the ascending aorta or coronary sinus, created by a slowly falling column of fluid, does not create a siphon that causes cavitation or the entrainment of air into the infusion lines. Such aspirated air could be infused directly into the patient by restarting the pump. Other anatomic locations of venting the heart include the pulmonary artery and the ascending aorta, with the latter usually drained through an antegrade cardioplegia cannula. Blood flow is, therefore, related to both the rpm of the cones or impellers and the total resistance. This represents an important safety feature in coupling blood flow with resistance. Impeller pump blades (center) push through the blood, causing damaging turbulence. The Medtronic Bio-Pump Plus centrifugal pump (right) promotes laminar flow, improving blood handling capabilities and decreasing blood trauma. However, when downstream occlusion occurs, either through increases in afterload or through the placement of line clamps, the fluid in the pump head will be heated because of hydrodynamic processes in the magnetic coupling. This increase in temperature could result in increased blood trauma and coagulation defects. However, when small quantities of air are aspirated into the pump head, these bubbles will coalesce and be passed into the outlet stream of fluid movement and potentially into the patient. There have been reports of thrombus formation when these pumps are used with low anticoagulation or for prolonged periods. Improved designs have addressed issues of stasis, heat generation, and bearing wear.

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Long-term mechanical circulatory support (destination therapy): on track to compete with heart transplantation Use of an intrapericardial erectile dysfunction emedicine order levitra extra dosage 100 mg fast delivery, continuous-flow erectile dysfunction medication names best purchase for levitra extra dosage, centrifugal pump in patients awaiting heart transplantation erectile dysfunction juicing cheap levitra extra dosage 40 mg on-line. Continuous flow left ventricular assist device outcomes in commercial use compared with the prior clinical trial erectile dysfunction treatment kolkata purchase 60mg levitra extra dosage with visa. Extended mechanical circulatory support with a continuous-flow rotary left ventricular assist device erectile dysfunction uncircumcised levitra extra dosage 100 mg otc. Outcomes in advanced heart failure patients with left ventricular assist devices for destination therapy erectile dysfunction pills cvs discount 60mg levitra extra dosage visa. Driveline infections in left ventricular assist devices: implications for destination therapy. Durability of continuous-flow left ventricular assist devices: a systematic review. Case series: clinical management of persistent mechanical assist device driveline drainage using vacuum-assisted closure therapy. Treatment of infected left ventricular assist device using antibiotic-impregnated beads. Diagnosis of hemolysis and device thrombosis with lactate dehydrogenase during left ventricular assist device support. Acquired von Willebrand syndrome after continuous-flow mechanical device support contributes to a high prevalence of bleeding during long-term support and at the time of transplantation. Acquired von Willebrand syndrome in patients with a centrifugal or axial continuous flow left ventricular assist device. Gastrointestinal bleeding rates in recipients of nonpulsatile and pulsatile left ventricular assist devices. Gastrointestinal bleed after left ventricular assist device implantation: incidence, management, and prevention. Hemolysis, pump thrombus, and neurologic events in continuous-flow left ventricular assist device recipients. Outcomes and long-term quality-of-life of patients supported by extracorporeal membrane oxygenation for refractory cardiogenic shock. Extracorporeal membrane oxygenation in the adult: a review of anticoagulation monitoring and transfusion. High incidence of upper-extremity deep vein thrombosis with dual-lumen venovenous extracorporeal membrane oxygenation. Hemolysis in pediatric patients receiving centrifugal-pump extracorporeal membrane oxygenation: prevalence, risk factors, and outcomes. Ethical dilemmas encountered with the use of extracorporeal membrane oxygenation in adults. Use of intensive care at the end of life in the United States: an epidemiologic study. Surgeons, intensivists, and the covenant of care: administrative models and values affecting care at the end of life. Predictors of operative risk for coronary bypass operations in patients with left ventricular dysfunction. Back from irreversibility: extracorporeal life support for prolonged cardiac arrest. Multicenter validation of a risk index for mortality, intensive care unit stay, and overall hospital length of stay after cardiac surgery. Pilot study of palliative care consultation in patients with advanced heart failure referred for cardiac transplantation. Palliative sedation therapy: a systematic literature review and critical appraisal of available guidance on indication and decision making. Because postoperative pain management has been deemed important, the American Society of Anesthesiologists has published practice guidelines regarding this topic. Pain may be associated with many interventions, including sternotomy, thoracotomy, leg-vein harvesting, pericardiotomy, and/ or chest tube insertion, among other interventions. Inadequate analgesia and/or an uninhibited stress response during the postoperative period may increase morbidity by causing adverse hemodynamic, metabolic, immunologic, and hemostatic alterations. Traditionally, analgesia after cardiac surgery has been obtained with intravenous opioids (specifically morphine). However, intravenous opioid use is associated with definite detrimental side effects (eg, nausea and vomiting, pruritus, urinary retention, respiratory depression), and longer-acting opioids such as morphine may delay tracheal extubation during the immediate postoperative period via excessive sedation and/or respiratory depression. Thus in the current era of early extubation (fast-tracking), cardiac anesthesiologists are exploring unique options other than traditional intravenous opioids for the control of postoperative pain in patients after cardiac surgery. No single technique is clearly superior; each possesses distinct advantages and disadvantages. It is becoming increasingly clear that a multimodal approach and/or a combined analgesic regimen (using a variety of techniques) is the best way to approach A postoperative pain in all patients after surgery to maximize analgesia and minimize side effects. When addressing postoperative analgesia in cardiac surgical patients, the choice of technique (or techniques) should be made only after a thorough analysis of the risk-benefit ratio of each technique in the specific patient in whom analgesia is desired. Pain and Cardiac Surgery Surgical or traumatic injury initiates changes in the peripheral and central nervous systems that must be addressed therapeutically to promote postoperative analgesia and, it is hoped, positively influence clinical outcomes (Box 42. The physical processes of incision, traction, and cutting of tissues stimulate free nerve endings and a wide variety of specific nociceptors. Receptor activation and activity are further modified by the local release of chemical mediators of inflammation and sympathetic amines released via the perioperative surgical stress response. The perioperative surgical stress response peaks during the immediate postoperative period and exerts major effects on many physiologic processes. The potential clinical benefits of attenuating the perioperative surgical stress response (above and beyond simply attaining adequate clinical analgesia) have received significant attention during the 2000s and remain fairly controversial. Pain after cardiac surgery may be intense, and it originates from many sources, including the incision (eg, sternotomy, thoracotomy), intraoperative tissue retraction and dissection, vascular cannulation sites, vein-harvesting sites, and chest tubes, among other sources. A subgroup (127 patients) also underwent long saphenous vein harvesting from either the calf (men) or thigh (women). Postoperative analgesic management was standardized and included intravenous morphine, oral paracetamol, oral tramadol, and subcutaneous morphine. Pain location, distribution, and intensity were documented in the morning on the first, second, third, and seventh postoperative days using a standardized picture dividing the body into 32 anatomic areas. A numerical rating scale of 0 to 10 (with 0 representing no pain and 10 representing the worst possible pain) was used to assess maximal pain intensity. These investigators found that maximal pain intensity was highest on postoperative day 1 and lowest on postoperative day 3. However, maximal pain intensity was only graded as moderate (mean pain score was approximately 3. Pain distribution did not appear to vary throughout the postoperative period, yet its location did (more shoulder pain was observed on postoperative day 7). As time after surgery increased, the pain usually moved primarily from the incisional and epigastric regions to osteoarticular areas. Another source of postoperative pain in patients after cardiac surgery is thoracic cage rib fractures, which may be common. In these patients, routine chest radiographs may appear normal despite the presence of fracture. Thus bone scans (better at detecting rib fractures than chest radiographic images) are recommended whenever unexplained postoperative nonincisional pain is present in a patient who has undergone sternal retraction. Age also appears to affect pain intensity; patients younger than 60 years of age often have greater pain intensity than patients older than 60 years of age. Although maximal pain intensity after cardiac surgery is usually only moderate, ample room for clinical improvement in analgesic control to minimize pain intensity remains, especially during the first few postoperative days. Postoperative brachial plexus neuropathies also may occur and have been attributed to rib fracture fragments, internal mammary artery dissection, suboptimal positioning of the patient during surgery, and/or central venous catheter placement. Younger patients appear to be at greater risk for the development of chronic, long-lasting pain. The correlation of severity of acute postoperative pain and the development of chronic pain syndromes has been suggested (patients requiring more postoperative analgesics may be more likely to develop chronic pain), yet this link is still vague. Ho and associates19 assessed 244 patients after cardiac surgery and median sternotomy and found that persistent pain (defined as pain still present 2 or more months after surgery) was reported in almost 30% of patients. The incidence rate of persistent pain at any site was 29% (71 patients) and for sternotomy was 25% (61 patients). Other common locations of persistent pain reported to these investigators were the shoulders (17%), back (16%), and neck (6%). However, such persistent pain was usually reported as mild, with only 7% of patients reporting interference with daily living. The most common words used to describe the persistent pain were "annoying" (57%), "nagging" (33%), "dull" (30%), "sharp" (25%), "tiring" (22%), "tender" (22%), and "tight" (22%). The temporal nature of this pain was mostly reported as being transient and intermittent. Thus it was concluded that mild persistent pain after cardiac surgery and median sternotomy is common yet only infrequently substantially interferes with daily life. Such pain may not become apparent until the late postoperative period, which may be related to the progression of patient mobilization and the decreasing impact of sternotomy pain (unmasking leg incisional pain). Using minimally invasive vein-graft harvesting techniques (endoscopic vein-graft harvesting) decreases the intensity and duration of postoperative leg pain, compared with conventional open techniques. Furthermore, leg morbidity (eg, infection, dehiscence) may be less in patients undergoing endoscopic vein-graft harvesting, compared with patients undergoing conventional open techniques because of different incisional lengths. Patient satisfaction with quality of postoperative analgesia is as much related to the comparison between anticipated and experienced pain as it is to the actual level of pain experienced. Satisfaction is related to a situation that is better than predicted, dissatisfaction to one that is worse than expected. Patients undergoing cardiac surgery remain concerned regarding the adequacy of postoperative pain relief and preoperatively tend to expect a greater amount of postoperative pain than that which is actually experienced. Thus patients may experience pain of moderate intensity after cardiac surgery yet still express very high satisfaction levels. Noxious input from an acute injury may trigger a state of central nervous system sensitization, called wind-up. In essence, dorsal horn neurotransmitter release via nociceptive input conditions the central nervous system in such a way that responsiveness (secondary hyperalgesia) is enhanced. Although experimental evidence indicates that enhanced responsiveness outlasts the initial provocative insult (induced sensitivity outlasts the stimulus), the exact clinical relevance remains to be determined. Advances regarding spinal cord neuropharmacology have led to research aimed at modifying or blocking N-methyl-D-aspartate receptors to influence pain control and the concept of preemptive analgesia, which is predicated on addressing pain before it initiates peripheral and central sensitization. However, given the redundancy in neurotransmitter receptor systems in the central nervous system, it is unlikely that blocking only one component will result in clear clinical benefits. Although the use of N-methyl-Daspartate receptor antagonists and the concept of preemptive analgesia are intriguing and certain clinical investigations appear to support their utility, clear and definite clinical benefits in humans remain to be determined. Debate continues over the potential benefits of N-methylD-aspartate receptor antagonists and the utility of preemptive analgesic treatment, as well as the direction in which research and conceptual development in this exciting field needs to proceed. Potential Clinical Benefits of Adequate Postoperative Analgesia Inadequate analgesia (coupled with an uninhibited stress response) during the postoperative period may lead to many adverse hemodynamic (tachycardia, hypertension, vasoconstriction), metabolic (increased catabolism), immunologic (impaired immune response), and hemostatic (platelet activation) alterations (Box 42. In patients undergoing cardiac surgery, perioperative myocardial ischemia (diagnosed by electrocardiography and/or transesophageal echocardiography) is most commonly observed during the immediate postoperative period and appears to be related to outcome. Techniques Available for Postoperative Analgesia Although the mechanisms of postoperative pain and the pharmacologic actions of analgesic drugs are relatively well understood, the delivery of effective postoperative analgesia remains far from universal. Finally, regarding intrathecal and epidural opioid analgesia, the existing literature supports the efficacy of epidural morphine and fentanyl for perioperative analgesia but is insufficient to characterize the spectrum of risks and benefits associated with the use of other specific opioids administered by these routes. Pruritus and urinary retention more frequently occur when morphine is given intrathecally or epidurally compared with systemic (intravenous or intramuscular) administration. Furthermore, epidural morphine provides more effective pain relief than intramuscular morphine. Similarly, epidural fentanyl provides more effective postoperative analgesia than intravenous fentanyl. The existing literature is insufficient to evaluate the effects of epidural techniques administered at different times (eg, preincisional, postincisional, postoperative). In 1991, Tuman and associates6 in another small (n = 80 patients), randomized, controlled clinical trial involving patients undergoing lower extremity revascularization revealed that patients who were managed with more intense perioperative anesthesia and analgesia demonstrated improved outcome compared with patients receiving routine on-demand narcotic analgesia. Existing evidence also indicates that aggressive control of postoperative pain in patients after cardiac surgery may beneficially affect outcome. Two intriguing clinical investigations published in 1992 hint at such possibilities. Standard-care patients received low-dose intermittent intravenous morphine for the first 18 postoperative hours, whereas intensive-analgesia patients received a continuous intravenous sufentanil infusion during the same time period. Patients receiving sufentanil demonstrated lesser severity of myocardial ischemia episodes (detected by continuous electrocardiographic monitoring) during the immediate postoperative period. The authors postulated that the administration of intensive analgesia during the immediate postoperative period may have more completely suppressed sympathetic nervous system activation, thereby having numerous beneficial clinical effects, including alterations in the sensitivity of platelets to epinephrine, alterations in fibrinolysis, enhanced regional left ventricular function, and decreased coronary artery vasoconstriction, all potentially leading to a reduced incidence and reduced severity of myocardial ischemia. Anand and Hickey9 prospectively randomized 45 neonates undergoing elective cardiac surgery (mixed procedures) to receive either standard perioperative care or deep opioid anesthesia. Standard-care patients received a halothane-ketaminemorphine anesthetic with intermittent intravenous morphine for the first 24 postoperative hours, whereas deep-opioid patients received an intravenous sufentanil anesthetic with a continuous infusion of either intravenous fentanyl or intravenous sufentanil during the same postoperative period. Neonates receiving continuous postoperative opioid infusions demonstrated a reduced perioperative stress response (assessed via multiple blood mediators), less perioperative morbidity (hyperglycemia, lactic acidemia, sepsis, metabolic acidosis, disseminated intravascular coagulation), and significantly fewer deaths than the control group (0/30 vs 4/15, respectively; p < 0. The Local Anesthetic Infiltration Pain after cardiac surgery is often related to median sternotomy, peaking during the first 2 postoperative days. One such alternative method that may hold promise is the continuous infusion of a local anesthetic (Box 42. All patients had two indwelling infusion catheters placed at the median sternotomy incision site at the end of surgery; one was placed in the subfascial plane above the sternum and the other one was placed above the fascia in the subcutaneous tissue. Average times to tracheal extubation were similar in the three groups (approximately 5 to 6 hours).