GFR = glomerular filtration rate.
V. CORNEAL TRANSPLANTATION
A. Corneas are the most common organs transplanted in the United States being performed under local anesthesia (often with intravenous sedation) or general anesthesia.
B. A major anesthetic goal is maintaining low intraocular pressure.
VI. RENAL TRANSPLANTATION
A. Preoperative Considerations. An enormous variety of diseases are treated with renal transplants (Table 51-4). About 50% of deaths of patients on dialysis are caused by heart failure. Hypercoagulable states are common in patients with renal disease.
1. All solid organ transplant patients are screened for tumors (mammography, Pap test, colonoscopy, prostate specific antigen) and infection (dental evaluation, viral serologies).
2. Extended criteria donors (age, creatinine, stroke or cardiac event as a cause of death, hypertension) are often used for kidney transplantation. (Minimization of cold ischemia times is essential.)
TABLE 51-4 DIAGNOSES OF PATIENTS ON ADULT RENAL TRANSPLANT WAITING LIST
3. Kidney allocations (blood type O kidneys allocated to type O recipients; blood type B kidneys are transplanted only in B recipients) are more complex than liver allocations.
B. Intraoperative Protocols. Renal transplantation is generally done under general anesthesia. Before incision, antibiotics are given. A central venous catheter (usually triple lumen) is placed for CVP monitoring and drug administration, and a bladder catheter is placed.
1. The major anesthetic consideration is maintenance of RBF.
2. Typical hemodynamic goals during renal transplant surgery are systolic pressure >90 mm Hg, mean systemic pressure >60 mm Hg, and CVP >10 mm Hg. Plasmalyte is the crystalloid of choice for kidney transplantation and preserves acid–base balance and electrolytes compared with Ringer’s lactate or normal saline.
3. After the first anastomosis is started, a diuresis is initiated (mannitol and furosemide are often both given). Dopamine does not reliably improve renal function in this setting.
4. Tight blood glucose control (80–110 mg/dL) during renal transplantation is a reasonable anesthetic management goal.
C. Patient-controlled analgesia is a good choice for postoperative pain management perhaps combined with combination blocks (ilioinguinal–iliohypogastric and intercostal nerve blocks). Chronic pain after renal transplantation is a common problem.
TABLE 51-5 DIAGNOSES LEADING TO LIVER TRANSPLANTATION IN ADULTS
HCV = hepatitis C virus.
VII. LIVER TRANSPLANTATION
A. Preoperative Considerations. Patients with end-stage liver disease (ESLD) have multisystem dysfunction with cardiac, pulmonary, and renal compromise because of their liver disease, and multiorgan dysfunction at the time of transplantation is common (Tables 51-5 and 51-6).
1. Patients with ESLD generally have very low systemic vascular resistance, high cardiac index, and increased mixed venous oxygen saturation. Echocardiography is also used to screen patients for portopulmonary hypertension and intracardiac shunts.
2. There is general agreement that mean pulmonary artery pressure above 50 mm Hg is an absolute contraindication to liver transplantation.
B. Intraoperative Procedures
1. Rapid sequence induction of general anesthesia is indicated because patients with ESLD often have gastroparesis in addition to increased intra-abdominal pressure from ascites.
2. A rapid infusion system with the ability to deliver at least 500 mL/min of warmed blood is primed and in the room. Normothermia, which is essential for optimal hemostasis, is maintained with fluid warmers and convective air blankets over the legs and upper body.
TABLE 51-6 MULTISYSTEM COMPLICATIONS OF END-STAGE LIVER DISEASE
FFP = fresh-frozen plasma; SVR = systemic vascular resistance.
3. Liver transplantation is traditionally described in three phases: the dissection, anhepatic, and neohepatic phases, with reperfusion of the graft marking the start of the neohepatic phase.
C. Coagulation Management
1. FFP is used to maintain an INR at ≤1.5 in patients with anticipated or ongoing bleeding.
2. Maintaining fibrinogen >150 mg/dL with cryoprecipitate is critical for hemostasis.
3. Perioperative renal dysfunction, with hypovolemia and anesthetic-induced reduction of RBF, is a major challenge in liver transplantation. Hepatorenal syndrome is a functional renal disorder that is associated with liver disease.
D. Pediatric Liver Transplantation. Indications for pediatric liver transplantation differ considerably from those in adults, with biliary atresia the most common indication. Portopulmonary hypertension is rare in children, but biliary atresia is associated with atrial septal defects and situs inversus.
E. Acute Liver Failure. Anesthetic considerations for both adults and children with acute liver failure are focused on protection of the brain. Patients with acute or fulminate hepatic failure may have a rapidly progressive course of elevated intracranial pressure (ICP), leading to herniation and death. Mannitol is used for osmotherapy to an end point of 310 mOsm/L, and hyperventilation is commonly used to manage ICP. Hypothermia is also considered brain protective in patients with acute liver failure.
VIII. PANCREAS AND ISLET TRANSPLANTATION
A. The majority of pancreas transplants (∼75%) are done as simultaneous pancreas and kidney transplants from a single deceased donor.
B. The major difference between pancreas transplantation and other procedures is that strict attention to control of blood glucose is indicated to protect newly transplanted β cells from hyperglycemic damage.
IX. SMALL BOWEL AND MULTIVISCERAL TRANSPLANTATION
A. In general, intestinal transplantation should only be considered in patients with life-threatening complications from intestinal failure.
B. For anesthesiologists, a major hurdle for these transplants is line placement that is adequate for transfusion of blood products and fluids, which may be substantial during these long procedures. Ultrasound devices are helpful in identifying the known patent vessels for cannulation, but surgical cutdowns for venous access may be necessary.
C. As in liver transplantation, nitrous oxide should be avoided.
D. Common complications of intestinal failure include dehydration and electrolyte abnormalities, gastric acid hypersecretion, pancreatic insufficiency, bone disease, and total parenteral nutrition–induced liver failure.
X. LUNG TRANSPLANTATION. Chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, and α1-antitrypsin deficiency are the most common indications for lung transplantation. Surgical options for lung transplantation are single-lung transplant, en bloc double-lung transplants, sequential double-lung transplants, and heart–lung transplantation.
A. Recipient Selection (Tables 51-7 and 51-8). Pulmonary function tests, left and right heart catheterization, and transthoracic echocardiography are routinely used for evaluating recipients.
B. Preanesthetic Considerations
1. By definition, lung transplant candidates have poor pulmonary status and are frequently receiving multiple therapies, including oxygen, inhaled bronchodilators, steroids, and vasodilators.
2. After determining oxygen saturation, slow, incremental dosing of a short-acting benzodiazepine (0.25–1.0 mg midazolam) is used for anxiolysis.
C. Intraoperative Management: Single-Lung Transplantation
1. Lung transplant recipients tend to be chronically intravascularly volume depleted, and anesthetic induction can be associated with hypotension.
2. Nitrous oxide is rarely an anesthetic option because of bullous emphysematous disease, pulmonary hypertension, or intraoperative hypoxemia.
3. Lung isolation, preferably with a double-lumen endotracheal tube, is necessary for single and bilateral sequential lung transplantation.
4. Lung recipients are susceptible to development of pulmonary hypertension and right ventricular dysfunction or failure during one-lung ventilation. Vasodilator or inotropic support may be required. Inhaled nitric oxide is another option for improving respiratory and right ventricular status.
TABLE 51-7 LUNG RECIPIENT SELECTION GUIDELINES
General Indications
End-stage lung disease
Failed maximal medical treatment of lung disease
Age within limits for planned transplant
Life expectancy <2–3 yrs
Ability to walk and undergo rehabilitation
Sound nutritional status (70%–130% of ideal body weight)
Stable psychosocial profile
No significant comorbid disease
Disease-Specific Indications
COPD
FEV1 <25% of predicted value after bronchodilators
PaCO2 >55 mm Hg
Pulmonary hypertension (especially with cor pulmonale)
Chronic oxygen therapy
Cystic fibrosis
FEV1 <30% predicted
Hypoxemia, hypercapnia, or rapidly declining lung function
Weight loss and hemoptysis
Frequent exacerbations, especially in young women
Absence of antibiotic-resistant organisms
Idiopathic pulmonary fibrosis
Vital capacity <60%–65% of predicted
Resting hypoxemia
Progression of disease despite therapy (steroids)
Pulmonary hypertension
NYHA functional status class III or IV despite prostacyclin therapy
Mean right atrial pressure <15 mm Hg
Mean pulmonary artery pressure <55 mm Hg
Cardiac index <2 L/min/m2
Eisenmenger syndrome
NYHA class III or IV despite optimal therapy
Pediatric
NYHA class III or IV
Disease unresponsive to maximal therapy
Cor pulmonale, cyanosis, low cardiac output
COPD = chronic obstructive pulmonary disease; FEV1 = forced expiratory volume in 1 second; NYHA = New York Heart Association.
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