Anesthesia for Organ Transplant and Harvest dictated slides 33-67

Liver transplant: 

Liver transplant Considered for patients in hepatic failure and for treatment of hepatoma, biliary tract tumor, and genetic metabolic conditions

Liver transplant (cont’d): 

Liver transplant (cont’d) Physiologic derangements often present before transplant Encephalopathy (confusion to coma) CHF Hypoxemia Anemia Thrombocytopenia DIC Hypokalemia, hypocalcemia Glucose intolerance Oliguria Ascites

Liver transplant (cont’d): 

Liver transplant (cont’d) Patients often very sick, especially with coagulopathies and portal hypertension Reperfusing the new liver will release a large load of toxins directly into the heart, which can cause complete arrest if potassium load high; push pressure way up from the start and have inotropic support ready

Liver transplant (cont’d): 

Liver transplant (cont’d) Positioned supine GETA +/- epidural (Check coags first) Surgeon makes large chevron incision in upper abdomen and dissects down to portal hepatis Hepatic artery, portal vein, proximal and distal IVC and bile duct are clamped, and old liver removed Donor liver placed and above reconnected Liver then reperfused and surgeon starts on biliary anastomosis, which is either an end-to-end anastomosis with the old bile duct or into a Roux-en-Y segment of jejunum

Liver transplant (cont’d): 

Liver transplant (cont’d) Takes approx 8 hours EBL: up to 5000 ml; T&C for 10 units of PRBC’s, FFP, and platelets Utilize RIS and cell saver for fluids Monitors: Standard plus Aline, CVP, PAC Radial artery preferred since abdominal aorta may be cross-clamped during hepatic artery anastomosis

Liver transplant (cont’d): 

Liver transplant (cont’d) Surgeons may use left arm for venovenous bypass procedures; femoral or portal vein to left axillary bypass is used to decompress the liver and lower extremities during clamping of the IVC; consider this when placing IV access Commonly place three introducers: one in each IJ and one in antecubital vein

Liver transplant (cont’d) : 

Liver transplant (cont’d) Characterized by three phases: Preanhepatic phase: involves mobilization and removal of native liver Cardiovascular instability due to hemorrhage, venous pooling due to sudden decreases in intra-abdominal pressure, and impaired venous return due to surgical retraction are part of this phase Hypocalcemia, hyperkalemia, and metabolic acidosis can occur Oliguria common

Liver transplant (cont’d): 

Liver transplant (cont’d) Anhepatic phase: Begins when native liver is removed after transection of blood supply and occlusion of suprahepatic and infrahepatic portions of the IVC To avoid drastic decreases in venous return and cardiac output as well as venous congestion (GI tract, kidneys), venovenous bypass may be utilized Can utilize IVC clamping or venovenous bypass Calcium administered to prevent hypocalcemia and citrate intoxication Placement of donor liver may require extensive retraction near diaphragm, impairing ventilation and oxygenation

Liver transplant (cont’d): 

Liver transplant (cont’d) Neohepatic phase: Begins with reanastomoses of major vascular structures Before removal of vascular clamps, donor liver flushed of air, debris, and preservative solution; despite this, unclamping can cause large release of potassium and metabolic acids Administration of clotting factors and Amicar for fibrinolysis may be given

Other considerations related to Liver transplant: 

Other considerations related to Liver transplant In pediatric patients or smaller adults (< 100#), liver lobe (left) segments can be utilized for partial transplant In adults, donor right lobectomy needed TIPS: transjuglar intrahepatic portosystemic shunt Procedure for treatment of esophageal varices Shunt placed radiographically and does not involve hepatic vascular anatomy

Pancreas transplant: 

Pancreas transplant Usually done for end-stage diabetics who are very sick preoperatively Commonly performed with kidney transplant from same donor (~75%) Takes approx 7 hours together (or 5 hours alone) EBL: 500 ml; T&C 2 units

Pancreas transplant (cont’d): 

Pancreas transplant (cont’d) Native pancreas left alone As with all transplants, keep perfusion pressure adequate, hydrate and transfuse early Large-bore IV access essential Monitors: Standard, Aline GETA +/- epidural

Pancreas transplant management: 

Pancreas transplant management Requires strict attention to glucose control Important to protect newly transplanted Beta cells from hyperglycemic damage Brittle diabetics  RSI May partially occlude aorta for anastomosis so BP will increase Reperfusion may elicit dysrhththmiasdecreased BP, increased HR, increased EtCO2

Pancreas transplant management: 

Pancreas transplant management Surgeon usually wants SBP ~120 after reperfusion Maintain with Neo/PRBC May request Dextran so have in room  start at 20 ml/hr Surgeon usually does not want glucose tx does not want Insulin gtt because after new pancreas in, produces insulin and patient becomes hypoglycemic

Small bowel transplant: 

Small bowel transplant Only considered with life-threatening intestinal failure Long procedure Complications Dehydration Electrolyte imbalances Gastric acid hypersecretion Pancreatic insufficiency Bone disease TPN-induced liver failure

Heart transplant: 

Heart transplant Only effective treatment for patients with end-stage heart disease due to CAD or cardiomyopathy Severe and irreversible pulmonary hypertension is an absolute contraindication to transplant because the normal right ventricle of donor heart is unable to abruptly compensate to a fixed and elevated PVR →heart and lung transplants are the only option in these patients EF < 20% and supported by inotropes oral or IV

Heart transplant (cont’d): 

Heart transplant (cont’d) Positioned supine Approx 6 hours EBL: 2000 ml; T&C 10 units PRBC’s, FFP, platelets, cryoprecipitate Increased bleeding when compared to other open heart surgery due to extent of exposed suture lines, length of bypass, preoperative GETA; remains intubated usually 24 hours postop

Heart transplant (cont’d): 

Heart transplant (cont’d) Monitors: Standard, Aline, CVP or PAC, TEE Place central lines in left IJ to save the right IJ for multiple endocardial biopsies post-transplant Will be necessary to pull back CVP or PAC into internal jugular when heart removed; catheter then repositioned into donor heart

Heart transplant (cont’d): 

Heart transplant (cont’d) Midsternal incision; bypass initiated and native heart removed at a line halfway across the atria; remaining atrial flaps sewn to transplanted atria, great vessels connected, patient rewarmed, and separation from bypass attempted May be complicated by right heart failure; treat with hyperventilation and pulmonary vasodilators (Isuprel or PGE1) Administer any vasoconstrictors via left atrial line so they will affect right heart AV node dysfunction may necessitate AV pacing

Heart transplant (cont’d): 

Heart transplant (cont’d) Transplanted heart is denervated Denervated heart has intrinsic rate of 70 May need drugs/pacing to increase rate to 90 to support cardiac output Inotropic drugs such as Isuprel may be needed to maintain contractility and heart rate Transplanted heart responds to direct-acting catecholamines with indirect drugs (Ephedrine) having less effect Heart rate responses do not occur with administration of anticholinergics or anticholinestarases

Heart transplant (cont’d): 

Heart transplant (cont’d) Most common cause of death post-transplant is opportunistic infection, possibly due to immunosuppressant therapy Cyclosporine-induced hypertension is present in majority of transplant patients ½ of patients develop CAD within 3 years post-transplant

Lung transplant: 

Lung transplant Selection criteria End-stage pulmonary disease with life expectancy < 18 months No other significant systemic disorder or psychiatric disorder No contraindication to immunosuppressant therapy Adequate support system Age < 60 (not always) Negative HIV No cigarette smoking, alcohol or drug abuse

Lung transplant (cont’d): 

Lung transplant (cont’d) Single-lung transplant (SLT) indicated for patients with end-stage respiratory failure, especially chronic interstitial pulmonary fibrosis Involves anastomosis of mainstem bronchus, left atrial cuff, and pulmonary artery Double-lung transplant (DLT) indicated for patients with COPD, cystic fibrosis, alpha 1-antitrypsin disease, idiopathic pulmonary hypertension Involves anastomosis of trachea, left atrium, and pulmonary artery

Heart-lung transplant: 

Heart-lung transplant Heart-lung transplant Involves anastomosis of trachea, aorta, right atrium

Lung transplant (cont’d): 

Lung transplant (cont’d) Exercise tolerance is zero May be admitted, induced and lined up then go home if tissue type is wrong or lung unsuitable Double lumen left-sided tube required Surgeon makes transverse thoractomy extended, dissects lung and removes it; donor lung reanastomosed and lung perfused while bronchial anastomosis completed; flap of omentum brought up from abdomen to secure around bronchial anastomosis

Lung transplant (cont’d): 

Lung transplant (cont’d) Positioned supine for DLT and lateral for SLT Takes approx 6 hours EBL: 500 ml; T&C 4 units PRBC’s,FFP, platelets GETA with epidural Monitors: Standard, Aline, PAC May have fair amount of hypoxia and hypercarbia with one lung ventilation; must tolerate it until ischemic shock passes Denervated donor lung deprives patient of normal cough reflex and predisposes to pneumonia

Pathophysiology of transplanted lung: 

Pathophysiology of transplanted lung Vagal denervation Decreased response to hypercapnia Increased sensitivity to narcotics Bronchodilation No change in HPV Occasional RLN damage Increased aspiration risk; Decreased pulmonary clearance →less effective cough Absence of lymphatics Risk of O 2 toxicity Release of free radical scavengers

Bone marrow transplant (BMT): 

Bone marrow transplant (BMT) Potential cure for fatal leukemias Combined with chemotherapy and total body radiation Donor bone marrow (1500 ml) harvested by multiple aspirations from superior iliac spines and crests GETA or regional Avoid N20 due to potential bone marrow depression

Graft-versus-host disease: 

Graft-versus-host disease Life-threatening complication of BMT Oral ulcers and mucositis Esophageal ulcers Fluid and electrolyte loss due to diarrhea Hepatic failure Coagulopathy Pancytopenia Acute respiratory failure Renal failure

Anesthetic considerations for post-transplant patients: 

Anesthetic considerations for post-transplant patients Must consider pathophysiology related to transplant Appropriate drug selection Denervation principles IV access Maintain adequate perfusion to transplanted organ Consider concomitant immunosuppressant regimen Strict aseptic technique! Most centers will have established protocols for management of transplant patients (pre and post transplant)