By H. Bozep. Carnegie Mellon University. 2019.
Management of an epidural catheter for postoperative analgesia must account for pharmacologic venous thromboprophylaxis 80mg super levitra sale impotence define. Ultrasound-guided regional anesthesia has led to a significant increase in use of peripheral nerve blocks and catheters as components of postoperative analgesic regimens discount super levitra online drugs for erectile dysfunction pills. A balanced multimodal analgesic regimen can include pharmacologic treatment with anti- inflammatories purchase super levitra 80mg with visa erectile dysfunction medications, acetaminophen, opioids, and medications that manage neuropathic components of pain, such as pregabalin. Such a multimodal approach has the potential to maximize analgesic efficacy while minimizing side effects. These blocks can be performed in combination with a sciatic nerve block and/or an obturator nerve block. Literature and clinical practice continue to evolve regarding which blocks or combination of blocks best facilitate rehabilitation and postoperative mobilization, thereby reducing time to hospital discharge, enhancing cost effectiveness, and reducing the risk for complications such as ambulation-related falls. Performing the77 block requires ultrasound guidance and a low local anesthetic volume placed distally within the adductor canal to avoid motor blockade to the vastus medialis. A selective79 tibial nerve block is an alternative that provides similar analgesia without the corresponding foot drop. Liposomal bupivacaine can be added to periarticular injections as a means to prolong the effect of the local anesthetic. The benefit of liposomal bupivacaine over standard local anesthetics is not conclusive, however, and both the safety profile and cost84 85 should be taken into consideration. Ambulatory Knee Surgery Ambulatory knee surgery has increased because health-care costs have encouraged outpatient management of less complex cases. An optimal anesthetic has a rapid onset and fast offset with minimal side effects so as to prevent prolonged postanesthesia care unit stays or unexpected overnight admissions. Neuraxial anesthesia results in a lower rate of nausea and vomiting than general anesthesia. However, in a practice with rapid turnover time and/or limited postanesthesia care unit capacity, the need to wait for block resolution may not be practical. In such settings, the use of general anesthesia with multimodal antinausea prophylaxis may be appropriate. In performing a spinal anesthetic in an ambulatory setting, a short-to- intermediate–acting local anesthetic should be utilized. This may be due to concomitant use of the anti-inflammatory ketorolac and dexamethasone for nausea prophylaxis. Evidence has not demonstrated a clinically significant difference in patient outcome with respect to anesthetic technique for ambulatory knee surgery. In younger and more active patients the autograft is preferred, but patellar tendon and hamstring grafts cause 3634 significant postoperative pain. Anesthesia for foot surgery can be performed with an ankle block or a sciatic nerve block in the popliteal fossa with a saphenous nerve block as needed for coverage of the medial foot and ankle (see Chapter 36). Some surgeons prefer ankle blocks in order to avoid the foot drop caused by a sciatic nerve block. A neuraxial or general anesthetic may be required to minimize patient movement and allow for thigh tourniquet inflation. Surgery to the foot and ankle can cause severe postoperative pain, and regional anesthesia provides optimal postoperative analgesia, particularly in the outpatient setting. Long-acting local anesthetics such as bupivacaine and ropivacaine can provide up to 24 hours of analgesia, and the addition of adjuvants like preservative-free dexamethasone can consistently extend analgesia beyond 24 hours. Peripheral nerve catheters may be93 challenging for noncompliant patients or those with limited access to follow- up care. In the outpatient setting, care must be taken to prevent accidental trauma to an anesthetized extremity, and patients should be instructed on how to best protect the limb upon discharge. Pediatric Orthopedic Anesthesia Pediatric patients present with a variety of orthopedic conditions, including congenital deformities, trauma, infections, and malignancies (see Chapter 43). Orthopedic procedures may be performed under regional, general, or a combination of anesthetic techniques depending on patient age, operative site, positioning, and surgical duration. The Pediatric Regional Anesthesia Network database has established the 3635 safety of regional anesthetic blocks and catheters in children. Special Considerations in Orthopedics Amputation Following amputation, many patients experience phantom limb pain, phantom limb sensations, and/or stump pain that can be chronic, debilitating, and difficult to manage. The incidence of persistent phantom limb pain is approximately 40% with upper extremity amputation and up to 85% after98 lower limb amputation. Prolonged outpatient local anesthetic administration99 (median 30 days) via perineural catheter may prevent phantom limb pain, with 84% of patients in one study reporting no pain at 12 months following lower limb amputation. Microvascular surgery can take many hours to perform, often requiring general anesthesia to maintain patient comfort and prevent movement. Mechanical ventilation can help avoid vasoconstriction caused by hyperoxia and hypocarbia as well as by hypercarbia-induced catecholamine release. Moreover, optimal anesthetic management for microvascular surgery utilizes regional techniques that provide sympathectomy (maximizing vasodilation) and diminish the stress response (minimizing vasospasm and thrombotic risk). Surgeons generally discourage vasopressors except in emergency situations, so their use must be discussed with the surgical team prior to initiation. However, rather than supporting adverse effects of vasopressor use, evidence suggests they may be beneficial for maintenance of flap flow. The cuff should be large enough to comfortably encircle the limb, and the width should be more than half the limb diameter. Damage to underlying vessels, nerves, and muscles can be caused by excessively high tourniquet pressures and/or prolonged inflation times. In general, a cuff pressure 100 mmHg above a patient’s measured systolic pressure is adequate for the thigh and 50 mmHg above systolic pressure is adequate for the arm. The duration of safe tourniquet inflation is generally considered to be 2 hours119,120; however, a perfusion break followed by repeat exsanguination may be considered if longer total tourniquet times are required. Breakthrough bleeding during tourniquet inflation is often due to intramedullary blood flow in long bones or small arterial vessels between the two bones of a distal extremity and cannot be resolved by tourniquet overinflation. Tourniquet pain can become significant over time and can be mitigated with opioids and/or hypnotics or definitively managed by tourniquet deflation. Transient systemic metabolic acidosis, increased arterial carbon dioxide levels, and a drop in systemic blood pressure can be expected with tourniquet deflation and are generally well tolerated in healthy patients. Early corticosteroid use in long-bone fracture patients may be beneficial in preventing the syndrome. Decreased arterial oxygen tension is the most consistent abnormal laboratory value. The syndrome is defined as occurrence of these events in temporal proximity to cementation, prosthesis insertion, joint reduction, or tourniquet deflation, with its severity defined by degree of hypoxemia and hypotension. Central venous pressure and possibly pulmonary artery catheter placement should be considered in medically fragile patients in whom cementation cannot be avoided. A summary of48 recommendations for neuraxial blockade in the setting of anticoagulants and draft updates from the fourth American Society of Regional Anesthesia Practice Advisory for Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy is presented in Table 51-3.
This risk can be minimized by ensuring they do not have an active pulmonary infection order super levitra online impotence gel, and that any increased airway resistance is minimized by the use of bronchodilator therapy buy discount super levitra 80 mg online list all erectile dysfunction drugs. Interestingly discount super levitra 80mg without a prescription erectile dysfunction doctors boise idaho, those with asthma are not at increased risk for atelectasis or pneumonia. Careful attention must be given to ensuring the bronchodilating regimens and steroid administration (either inhaled or systemic) are continued throughout the perioperative period. Patients correctly use incentive spirometers only 10% of97 the time unless therapy is supervised. The single most important aspect of postoperative pulmonary care is getting the patient out of bed, preferably walking. The behavior of the abdominal muscles and intra- abdominal pressure during quiet breathing and increases pulmonary ventilation: A study in man. Effect of mechanical ventilation on cytokine response to intratracheal hypopolysaccharide. Mechanical ventilation-induced lung release of cytokines: a key for the future or pandora’s box? Partially and totally unloading respiratory muscles based on real-time measurements of work of breathing. Inspiratory pressure support compensates for the additional work of breathing caused by the endotracheal-tube. The effects of increased resistance to expiration on the respiratory behavior of the abdominal muscles and intraabdominal pressure. Localization and patterns of discharge of respiratory neurons in the brainstem of a cat. Electrical stimulation of points in the forebrain and mid-brain: The resultant alterations in respiration. Effect of volume and rate of inflation and deflation on transpulmonary pressure and response of pulmonary stretch receptors. Contribution of peripheral chemoreception to the depression of the hypoxic ventilatory response during halothane anesthesia in cats. Discharge patterns of brainstem respiratory neurons in relation to carbon dioxide tension. Distribution of blood flow in isolated lung; relation to vascular and alveolar pressures. Pressure-volume curve of total respiratory system in acute respiratory-failure—computed tomographic scan study. Unilateral hypoventilation in man during temporary occlusion of one pulmonary artery. Respiratory dysfunction and pulmonary disease in cirrhosis and other hepatic disorders. Oxygen tensions and oxyhemoglobin saturations in the assessment of pulmonary gas exchange. Preoperative evaluation of pulmonary-function—validity, indications, and benefits. Pulmonary diffusing capacity: A comparison of breath- holding and steady-state methods using carbon monoxide. Assessment of operative risk in patients undergoing lung resection—importance of predicted pulmonary-function. Practice advisory for preanesthetic evaluation: A report by the American Society of Anesthesiologists. Accuracy of the preoperative assessment in predicting pulmonary risk after non-thoracic surgery. Anesthetic effects on ventilation in patients with chronic obstructive pulmonary disease. The effects of ventilatory pattern on hyperinflation, airway pressures, and circulation in mechanical ventilation of patients with severe airflow obstruction. Pulmonary densities during anesthesia with muscular relaxation: A proposal of atelectasis. The effects of anesthesia and 100 percent oxygen on the functional residual capacity of the lungs. Effects of anesthesia and muscle 994 paralysis on respiratory mechanics in normal man. Effects of continuous positive-pressure breathing on functional residual capacity and arterial oxygenation during intra- abdominal operation. Temporal responses of functional residual capacity and oxygen tension to changes in positive end-expiratory pressure. Augmentation of elastase-induced emphysema by cigarette smoke: effects of reducing tar and nicotine content. Bronchoalveolar lavage cell-lymphocyte interactions in normal non-smokers and smokers. Nicotine is responsible for airway irritation evoked by cigarette smoke inhalation in men. Preoperative cessation of smoking and pulmonary complications in coronary artery bypass patients. Cytology of respiratory epithelium as a predictor of respiratory complications after operation. Effects of preoperative smoking cessation on the incidence and risk of intraoperative and postoperative complications in adult smokers: a systematic review. The anesthesia preoperative assessment: an opportunity for smoking cessation intervention. Role of preoperative cessation of smoking and other factors in postoperative pulmonary complications: a blinded prospective study of coronary artery bypass patients. A comparison of sustained-release bupropion 995 and placebo for smoking cessation. Varenicline, an alpha4beta2 nicotinic acetylcholine receptor partial agonist, vs sustained-release bupropion and placebo for smoking cessation: a randomized controlled trial. Influence of smoking fewer cigarettes on exposure to tar, nicotine, and carbon monoxide. Effect of patient-controlled analgesia on pulmonary complications after coronary artery bypass grafting. Can postoperative pulmonary complications be improved by treatment with Bartlett Edwards incentive spirometer after upper abdominal surgery? Comparison of continuous positive airway pressure, incentive spirometry, and conservative therapy after cardiac operations. Preoperative pulmonary risk stratification for non-cardiothoracic surgery: a systematic review for the American College of Physicians.
Modern anesthetic systems make ventilation much easier than in the past cheap 80 mg super levitra with mastercard erectile dysfunction 60, even in the smallest patients purchase super levitra cheap erectile dysfunction fpnotebook. Although the standard has been to use pressure control ventilation in this population super levitra 80 mg low cost erectile dysfunction treatment vitamins, all modes of ventilation are now readily available on modern anesthesia machines. Table 42-4 shows the modes of ventilation and breath synchronization most commonly used in neonates. Use of high frequency ventilation in the operative setting will require use of a specialized ventilator and close consultation with a critical care physician and respiratory therapist. Table 42- 5 lists some of the advantages and disadvantages to use of pressure control, volume targeted, and high frequency ventilation. Table 42-4 Common Ventilator Strategies in Neonates Impact of Surgical Requirements on Anesthetic Technique Every procedure has its own unique challenges. With any surgery, issues related to presurgical resuscitation, perioperative fluid and blood loss, 2974 heat loss from the surgical field, likely perioperative complications, and the likely need for postoperative intubation and ventilation should be anticipated, both on the basis of experience and communication about the unique needs of the upcoming procedure. There is a dramatic increase in the use of laparoscopic and thoracoscopic approaches to lesions, even in the smallest neonates. There may be less blood, fluid, and heat loss, but there are additional issues related to positioning, insufflation pressures in the chest and abdomen, and prolonged surgical time. As new techniques evolve, close communication between the anesthesiologist and the surgeon is necessary to ensure adequate preparation, monitoring, and resolution of problems or complications. One not well-recognized factor that may result in higher concentrations of volatile anesthetics being administered to infants has to do with the use of nonrebreathing systems such as the Bain or a Mapleson “D” circuit. When an adult circle system is used with infant tubes and bag, the clinician experienced with this equipment is used to reading the inspired, end-tidal, and dialed concentrations of the volatile anesthetic. In the circle system, the inspired concentration is a result of the combination of the end-tidal concentration that is rebreathed through the soda lime absorber and the dialed concentration. The inspired concentration is always lower than the dialed concentration, unless the flow rates are so high that a nonrebreathing system has been created. In the nonrebreathing system, the dialed concentration is the inspired concentration. However, if the clinician switches back and forth between the circle system and a nonrebreathing circuit, but does so infrequently, there is a danger of not recognizing the possibility of excessive overpressure of volatile anesthetics with the nonrebreathing systems. The newborn infant has elevated progesterone levels, similar to those of the mother. Elevated levels of β-endorphin and β-lipotropin have been demonstrated in infants in the first few days of postnatal life. Regional Anesthesia 2976 There has been a tremendous increase in the use of regional anesthesia in infants and children. In general, regional techniques are combined with general anesthesia to permit early extubation and provide postoperative pain relief. Useful regional anesthesia techniques include spinal anesthesia, caudal anesthesia, epidural analgesia, penile block, and other peripheral nerve blocks (Table 42-6). Regional anesthesia may even have other applications outside surgery, including management of neonatal limb ischemia. The use of ultrasonography has revolutionized the use of regional anesthesia as vascular structures can be easily avoided while still providing a regional blockade. The use of sole regional anesthesia in neonates and infants is for avoidance of general anesthetics, for either theoretical decreased risk of apnea or decreased risk of neurotoxicity. Although neurotoxicity trials are still ongoing, it has been shown that spinal anesthesia decreases early apnea following surgery in premature neonates, but does not decrease the risk of overall apnea following surgery in premature neonates. Some patients may benefit from providing a caudal block in addition to the spinal anesthetic. Total spinal anesthesia, produced either with a primary spinal technique or secondary to an attempted epidural puncture, will present as apnea, rather than as hypotension, because of the lack of sympathetic tone in infants. The exact mechanism for the lack of cardiovascular change with spinal anesthesia in infants and young children is not clear. Consequently, the first indication of a high spinal is falling oxygen saturation rather than a falling blood pressure. Sedation can be added to regional anesthesia but may cause problems with apnea in ex-premature infants. The landmarks are the coccyx, the two sacral cornua, and the posterior superior iliac spines (Fig. Several needle types may be used, but the “pop” through the sacrococcygeal ligament is best observed with a blunt-tipped needle, whereas an intravenous catheter advanced over a needle may provide additional confirmation of sacral canal entry. The caudal space is identified by “pop” through the sacrococcygeal ligament, ease of local anesthetic injection, and absence of subcutaneous swelling upon dose delivery. Once the sacrococcygeal ligament is penetrated and there is a loss of resistance, gentle aspiration is applied to the needle to determine if there is blood or cerebrospinal fluid. If there is difficulty in injecting the solution, and the tip of the needle is not in the caudal space and it needs to be repositioned. The needle is not advanced up the sacral canal after proper placement in the caudal epidural space has been accomplished, this avoids dural puncture and accidental intrathecal injection. Other methods to identify the caudal space have been described, including stimulating technique129 and ultrasound guidance. Evidence of an intravascular injection include (1) peaked T waves (which may be of relatively short duration), (2) increase in heart rate, and (3) increase in blood pressure. Another technique to minimize the potential difficulties of an intravascular injection is to fractionate the dose by dividing the total dose into three aliquots and waiting approximately 20 to 30 seconds between each aliquot before continuing the injection. In addition, a single-injection caudal anesthetic can provide analgesia for 6 to 8 hours. Epinephrine, 1:200,000, is added to local anesthetics to assist in determining if there has been an intravenous injection. Ropivacaine has been reported to be less cardiodepressant than equipotent doses of bupivacaine. If a caudal catheter is placed, an infusion of ropivacaine, bupivacaine, lidocaine, or chloroprocaine can be administered and provide analgesia for several days postoperatively. Current recommendations for infusions in neonates and young infants are for an initial loading dose of 0. The addition of clonidine,73 1 to 2 μg/kg, to local anesthetic for caudal block has been used, but may not enhance analgesia. However, caution must be exercised in neonates and infants who may be prone to apnea with even moderate doses of opioids in the epidural space. Ultrasonography can be used for localization of the caudal space in infants whose anatomy may not be apparent. This provides analgesia for hernia repair, circumcisions, and lower abdominal surgeries.
Since the intrapericardial volume is constant purchase super levitra from india erectile dysfunction psychological causes treatment, cardiac chambers are compressed when at their lowest pressure (atria in systole super levitra 80mg with mastercard erectile dysfunction vitamin deficiency, ventricles in diastole) discount super levitra on line erectile dysfunction drugs non prescription. In summary, diastolic filling is an active process and a major component of effective cardiac performance. Evaluation of Valvular Heart Disease Two-dimensional echocardiography and Doppler are complementary methods 1870 in valve assessment. The 2D echocardiography provides evaluation of valve anatomy and function; Doppler assesses the physiologic consequences and severity of the lesion. B: M-mode echocardiography demonstrates separation of the epicardium from the pericardium (asterisks) from pericardial effusion. However, for any given68 valve area, the flow velocity and pressure gradient vary with changes in stroke volume and cardiac output. The2 echocardiographic cut-off values for grading aortic stenosis are shown in Table 27-3. The leaflets can appear thickened and calcified (thus, strongly echogenic), and there may be fusion of the chordae and papillary muscles. The right ventricle may be dilated and/or hypertrophied, with thickened walls, because of increased pressure work (Fig. The increased diastolic pressure gradient is measured with continuous Doppler in the midesophageal four-chamber or long-axis view. The early diastolic velocity of the transmitral flow (E wave)67 is increased (usually >1. B: In the midesophageal bicaval view, red blood cell clumping creates spontaneous echocardiography contrast. The anterior mitral leaflet exhibits diastolic doming whereas the posterior mitral leaflet is immobile. A: Diastolic blood acceleration upstream of the mitral valve is seen with color-flow Doppler (“rising sun”). B: Spectral display of the diastolic velocity decay is imaged with a pulsed-wave Doppler sample volume placed at the tips of the mitral valve. Echocardiographic findings may include any of the following:77 abnormal texture of leaflets (myxomatous degeneration), flail and/or prolapsing leaflet, ruptured chordae, papillary muscle dysfunction or rupture (secondary to ischemia), mitral annulus calcification, or endocarditis lesions. The leaflet motion is commonly reported using Carpentier classification as described in Table 27-6. In routine cases, such as coronary artery bypass surgery, evaluation of the aorta may reveal previously unknown, significant atheromatous disease of the aorta and alter the surgical plan (off-pump bypass, alternative sites for cannulation). In emergencies, the diagnosis of aortic pathology (dissection, aneurysm, transection) may prove life-saving. Atherosclerotic plaques are irregularly shaped, sometimes mobile protrusions inside the aortic lumen. The search for atheromas should be done by imaging the entire circumference of the aortic lumen (short-axis views). Once a particular lesion is found, scanning in long-axis view should be performed (Fig. Ascending aorta aneurysm distal to the sinotubular junction (midesophageal ascending aorta long-axis (A) and short-axis (B) views). C: Ascending aorta dissection (Stanford type A) originating from the sinotubular junction. Color-flow Doppler demonstrates blood flow inside the true lumen (which expands in systole) and the absence of flow inside the false lumen. Dissection is a separation between the intimal and medial layers of the aortic wall, creating a false lumen for blood flow (Figs. Both the true and false lumens fill with blood during82 systole, but only the true lumen has blood flow during diastole. Intramural hematoma is considered a precursor of dissection and should be treated similarly. Cardiac Masses Cardiac tumors either can originate from the heart or are metastases from other sites. The most common primary tumor is myxoma, which is located most frequently at the interatrial septum (Fig. The potential of 1882 myxomas to obstruct the inflow or outflow region of a ventricle is demonstrated with Doppler echocardiography. Pacemaker wires, thrombus, and normal anatomic structures that mimic the appearance of pathology (Eustachian valve, crista terminalis, Chiari network, or “Coumadin” ridge) should be differentiated from tumors. Ultrasound-guided Central Vein Cannulation The placement of central venous catheters is associated with complications including injury to vascular structures (carotid artery), pleura, nerve bundles, lymphatic system, and even the spinal canal. Historically, anatomic landmarks guided needle orientation during central venous access. However, multiple studies have demonstrated that the anatomic relationship between the internal jugular vein and the carotid artery varies and that even experienced physicians encounter complications. Visual guidance by ultrasound provides85 real-time feedback, reducing the complication rate and the procedure time. In the midesophageal four-chamber view, a color-Doppler sector is positioned over the interatrial septum. The American Society of Echocardiography in collaboration with the Society of Cardiovascular 1886 Anesthesiologists has issued guidelines for the performance of epicardial echocardiography. The guide wire is seen as a thin echo-dense linear structure positioned in the lumen of the vein. Epiaortic scanning for atheroma is performed using a small footprint, linear array transducer. The echocardiography report from a preoperative examination is useful for assessing surgical risk and developing the anesthetic plan. Echocardiography has also established itself as particularly valuable in the assessment of postoperative hemodynamic instability. It offers rapid diagnosis by differentiating among the potential complications faced in postoperative care, such as hypovolemia, pericardial tamponade aortic dissection, myocardial infarction, endocarditis, and pulmonary embolism. Advancements in portable ultrasound technology have led to the wide availability of these devices throughout the hospital. As such, focused exams are increasingly performed at the bedside as an adjunct to the clinical exam by anesthesiology and critical care physicians lacking advanced training in echocardiography. The importance of structured training and maintenance of competencies has been recognized by 1888 professional societies as essential components to fully utilize the advantages and minimize drawbacks of this type of cardiac ultrasound examination. The aortic valve (arrow) is thickened and heavily calcified with restricted mobility. Focused Exam Views A focused cardiac examination uses transthoracic echocardiographic images obtained from the parasternal, apical, and subcostal windows. In 1889 addition, most of the cardiac abnormalities sought out can be easily recognized from these windows. Parasternal views are obtained in the third intercostal space at the left sternal border with the patient in left lateral position.
Displacement 250 ± 25 ml 400 ± 20 ml 150 ml reduction volume (not including cannulas) 6 cheap super levitra 80mg erectile dysfunction juice drink. Valves 25 M (mitral) and 23A 27 M (mitral) and 25A Next available (aortic) (aortic) smaller valve sizes (titanium housing and (titanium housing and selected pyrolytic carbon tilting pyrolytic carbon tilting disk) disk) 8 buy genuine super levitra erectile dysfunction doctor orlando. Diaphragms Four diaphragms: one Four diaphragms: one Same number of blood diaphragm and blood diaphragm and diaphragm and three redundant three redundant same diaphragm diaphragms (air and diaphragms (air and thickness purchase 80mg super levitra with mastercard erectile dysfunction natural foods. Te amount of cardiac out- rior distance greater than 10 cm from the sternum put needed to warrant end-organ recovery, spe- to the tenth thoracic vertebra (T10) . Two 1 cm stab wounds are distance lower than 10 cm and post-device chest made under the lef costal margin. A surgical imaging showed no compression of pertinent intra- clamp is passed from the lef upper abdominal thoracic structures, as predicted by the pre-device quadrant, thru the stab wound and into the medi- simulation. Te basis in the clinical feld and requires time to driveline from the prosthetic ventricle is then receive an indication in a feld in which time jokes inserted into the chest. Te chest tube is then a pivotal role and the availability of the 50-cc pulled from the mediastinum and outward pull- makes such an approach less needed. Each measure of the anteroposterior diameter at the driveline open tip is then covered to prevent fuid level of the diaphragm (. Te driveline ble to indicate the selection of the right machine from the prosthetic lef ventricle is to the lef of for the patient. Te excess ring is cut at this time Implantation leaving a ring width of about 4–5 mm. Te pericardium is Intravenous heparin is administered to bring opened to expose the native heart. Cardiopulmonary bypass is tapes are also placed around the superior and established, the heart is fbrillated, and the aorta is 326 J. V-shaped incision is now made, excising the right ventricular outfow tract with the pulmonic valve in toto with care not to enter the mitral or tricus- pid valve annulus. Tis exposes the continuity of the anterior leafet of the mitral valve with the lef coronary cusp of the aortic valve. Te coronary sinus is then closed with a running 3-0 or 4-0 poly- propylene suture at this time. Tis will prevent back bleeding from all the veins that have been divided during the ventriculectomy. Te needle is passed from inside to outside, going through the “skirt” of the atrial quick connect, mitral valve annulus, and the muscle full thick-. The needle is passed from inside to outside, going through the “skirt” of the atrial quick connect, valve annulus, and the muscle full thickness. The atrial quick connects are then reverted into their original confguration 327 32 The Total Artifcial Heart. Each suture is pulmonary artery conduit is usually 2–3 cm lon- then run to complete the circumference, advanc- ger than the aortic conduit. Te ventricles are ing no more than 2 mm to avoid areas of separa- then removed from the mediastinum and placed tion in the suture line. When a separation between conduits are anastomosed to their respective the skirt of the quick connects and the muscle artery with a running suture of 4-0 polypropylene occurs, a “scallop”-shaped deformity is created in (. Te suture line on blunt-tipped needle drivers are placed side by the lef side will go through the anterior leafet of side on the ring of the atrial quick connect or the mitral continuation with the lef coronary arterial conduit. A 27 mm tester could be used for leafet of the aortic valves that was exposed earlier. Te tester may be posi- tricuspid valve annulus and sutured in a similar tioned at 180° from the needle drivers and gently way. A 60 cc syringe with saline is con- atrial quick connects are then reverted into their nected to the tester and pressurized with one original confguration. Te lef atrial mediastinum with its infow resting over the lef quick anastomosis is the most difcult to test as atrial quick connect. A rotated to the lef, and its outfow aimed toward similar test may be performed in the right atrial, the aorta. Tis will provide the necessary length of pulmonary artery, and aortic anastomosis. Te conduit can then be cut to pulmonary artery conduit requires placement of a this length. Te prosthetic lef ventricle is lef in cross clamp distal to the suture line to adequately the mediastinum, and the right ventricle is test this suture line. Any leaks are corrected at this brought in and allowed to rest on the right quick time with interrupted 3-0 or 4-0 polypropylene connect, aiming toward the pulmonary artery. Once the patient is hemody- namically stable, protamine is administered to reverse the heparin. The orientation of the ventricles Once bleeding has stopped, chest tubes are has to be preset prior to the connection taking place. The placed in the mediastinum and in the pleural cav- ventricle is then connected to the aortic conduit in a similar ities if necessary. Te sternum and the chest are fashion while installing saline to remove as much air as pos- closed in the usual fashion. The prosthetic right ven- tricle is connected in a similar fashion; frst to the right atrial exiting the skin are secured to the skin at the sur- quick connect. If bleeding persists because of a machine to the patient by removing one of the tourniquets coagulopathy, the mediastinum can be packed in the cava until blood flls and deairs the right ventricle. The with laps and the sternum lef open and covered 32 ventricle is then connected to the pulmonary artery conduit with two layers of Ioban antimicrobial drape (3 M, St. Tis will be used later to cover the lef pression of the cavae or pulmonary veins when side of the device and will minimize adhesions at the sternum is re-approximated. Te two blunt-tipped toward the patient’s lef at the time of sternal needle drivers are placed in the lef atrial quick re-approximation. Te orientation of the ventricles has to be preset prior to the connec- tion taking place. Te prosthetic right Te technique to facilitate mediastinal re-entry ventricle is connected in a similar fashion; frst to utilizes three components: (1) blue polyisoprene the right atrial quick connect. Te upper part of the most proximal one placed around the aorta is folded down into the space between aorta and right atrium. Te sheet over the right atrium can be tacked down with interrupted sutures to the peri- cardium near the venae cave to prevent migra- tion. Chest and mediastinal drainage tubes are placed at this time in a routine fashion. For better necessity for dissecting the structure during the subsequent operation drainage, several slit openings of about 0. Te entire length of each membrane remains between the sternal wires and vascular structure is covered in order to avoid underside of the sternum and not be displaced adhesion formation, minimizing the necessity for between the blades of the sternum. Te main advantage of saw is used to perform the sternotomy in a rou- this method is that no adhesions form around tine fashion at a level above the silicone mem- these latex-free bands. Tis facili- and replacement therapy are associated with an tates exposure of the device as adhesions are min- increased risk of multiorgan failure.