ANESTHESIA FOR KIDNEY TRANSPLANTATION

Indications

•  Polycystic kidney disease

•  Diabetes mellitus–related kidney failure

•  Hypertensive kidney disease

•  Glomerular disease

•  Tubulointerstitial disease

•  Other familial or congenital diseases

Preoperative Evaluation

•  Check electrolytes the morning of surgery (delay surgery if K⁺ >6.0 mEq/L)

•  Should have dialysis within 24 hrs of surgery

•  Typical comorbidities

CAD = major cause of death in ESRD pts before & after transplant

Electrolyte abnl, HTN, DM, delayed gastric emptying, acidosis, anemia

CHF (from vol overload & compensatory concentric cardiomyopathy)

Coagulopathies (qualitative platelet defect in uremic pts), pericarditis

Intraoperative Management

•  Standard monitors (avoid placing BP cuff on fistula arm)

•  Consider A-line (if indicated by comorbidities)

•  Consider central line—CVP monitoring, ability to give thymoglobulin

May be difficult to place (prior dialysis lines)

Induction & Maintenance

•  Usually GA (RSI if gastroparesis suspected—i.e., long-standing diabetes)

•  Spinal & epidural not typically implemented (platelet dysfx in uremic pts)

•  Avoid enflurane & sevoflurane (inorganic fluoride byproduct may accumulate)

•  Paralytics

• Consider avoiding succinylcholine (may elev. K⁺ 0.5 mEq upon induction)

• Vecuronium & pancuronium may have prolonged effects

• Atracurium & cisatracurium not affected by ESRD (Hoffman degradation and nonenzymatic ester hydrolysis)

•  Narcotics

• Morphine, meperidine, oxycodone metabolites can accumulate & prolong duration

• Fentanyl, sufentanil, alfentanil, remifentanil may be safer alternatives

Surgical Procedure

•  8–10 cm arced incision from pubic symphysis to anterior superior iliac spine

•  Graft anastamoses usually made to external iliac vein & artery

External iliac artery & vein clamped for anastamoses

•  Graft warm ischemia time is usually about 15–30 min

•  Bladder filled via Foley catheter (to facilitate ureteral anastomosis to bladder)

•  Native kidney only removed if pt has intractable HTN or chronic infection

Specific Intraoperative Considerations

•  Hypotension may ensue with unclamping of iliac vessels & graft reperfusion

Avoid α-adrenergic agents that cause graft vessel vasoconstriction (phenylephrine)

Low-dose dopamine (3–5 mcg/kg/min) may be a better option

•  Heparin may be requested before clamping of iliac vessels

•  ↑ preload (CVP of 12–15 & MAP >60) before unclamping/reperfusion by administering 0.9 NS (3–5 L may be needed) or colloid

•  Mannitol may act as free radical scavenger & help diurese kidney after reperfusion (furosemide also used); goal urine output >0.5 mL/kg/hr

•  Ca-blocker admin before vessel anastomosis may prevent reperfusion injury

•  Consider bicarbonate infusion for significant metabolic acidosis (pH <7.2)

Immunosuppressive Agents

•  Typical combination: Corticosteroids, cyclosporine (or tacrolimus), & azathioprine (or mycophenolate mofetil)

•  Can delay cyclosporine & tacrolimus a few days & use antithymocyte globulin instead

Postoperative Management

•  Pt usually extubated

•  Goal urine output >0.5 mL/kg/hr

ANESTHESIA FOR LIVER TRANSPLANTATION (ALSO SEE CHAPTER 18, ANESTHESIA FOR GENERAL SURGERY)

General

•  1-yr survival following transplant 80–90%; 5-yr survival: 60–80%

•  Organ allocation: Based on MELD (model of end-stage liver dz) or PELD (pediatric) score

•  Increasing use of Non-Heart Beating Donation (NHBD), although still a small minority; also more use of extended donor criteria organs (age >70, DM, HTN, atherosclerotic heart dz) requiring more rapid reperfusion

Preoperative Evaluation

•  Underlying diagnoses of recipients

Hepatitis C (28%), EtOH (18%), cryptogenic cirrhosis (11%), primary biliary cirrhosis (9%), primary sclerosing cholangitis (8%), fulminant (6%), autoimmune (6%), hep B (4%), EtOH + hep C (4%), HCC (2%), metabolic (4%), other (4%)

•  Extrahepatic manifestations of liver disease: correctible problems include coagulopathy (platelet & FFP admin) pleural effusions (thoracentesis)

Intraoperative Management

•  Venous access

• Large-bore peripheral access (RICC line or 8.5 Fr peripheral IV)

• 8.5 or 9 Fr central venous catheter

• May need additional access if PA catheter is in lumen of 8.5 or 9 Fr central catheter

•  Standard monitors; A-line preinduction; CVP; consider PA catheter & TEE

•  Equipment

• Stat lab must be close by & available

• Rapid infuser systems (Level I, Belmont, etc.) set up & available

• Blood products available (usually 10 U FFP, 10 U PRBCs, & platelets)

• Venovenous bypass machine (with perfusionist) available

• Cell saver

Induction and Maintenance

•  Usually RSI (for “full stomach” precautions) or awake intubation

•  Pts often coagulopathic (use care when placing lines, ETT, NG tube)

•  Inhalational agents, narcotics, & muscle relaxants during maintenance

•  Avoid ketamine—can ↑ seizure activity

•  Moderate coagulopathy is permissible, provided there is no clinical bleeding

• Aggressive use of blood products may worsen outcome

• Conservative fluid management in selected patients

•  Maintain normothermia

Postoperative Management

•  Peripheral nerve injuries commonly due to positioning

•  Following skin closure, patient brought to ICU (usually intubated)

ANESTHESIA FOR LUNG TRANSPLANTATION

Indications

•  COPD, idiopathic pulmonary fibrosis, cystic fibrosis (CF), α1-antitrypsin deficiency, PPH (primary pulmonary HTN)

•  Terminally ill patients with end-stage lung disease

•  Less frequently: Sarcoidosis, retransplantation, Eisenmenger’s syndrome

Indications for Heart–Lung Transplantation (HLT)

•  Pts with lung transplant indication & significant left ventricular dz

•  Most commonly PPH, CF, & Eisenmenger’s syndrome

Single-Lung Transplantation (SLT) vs. Bilateral Sequential Lung Transplantation (BSLT)

•  BSLT = 1 lung transplanted (start with native lung with worse function) followed by a repeat procedure on contralateral side

Preoperative Evaluation

•  Lab values: ABO compatibility of donor & recipient

•  Radiography, echocardiography (RV failure)

• Functional data (including PFTs) & left heart cath (exclude CAD and intracardiac shunt)

•  Pts may have difficulty lying flat (poor pulm function)

Intraoperative Considerations

•  Standard monitors + A-line, central line, PA catheter; consider TEE (assess RV fx)

•  Lung isolation techniques (fiberoptic scope necessary)

•  2 large-bore IVs; ± epidural catheter

•  Be ready for emergent initiation of cardiopulmonary bypass

Induction and Maintenance

•  Lung isolation: Double-lumen tube, univent tube, or ETT + bronchial blocker

•  Avoid N₂O (presence of bullous emphysematous dz, pulm HTN, intraop hypoxemia)

•  Fluid management usually conservative (helps with postop management)

•  Permissive hypercapnea

•  Be vigilant for cardiac instability or pneumothorax on nonoperative side

Surgical Procedure for Single-Lung Transplantation

•  Posterolateral thoracotomy position (need for rapid access to cannulation sites for emergent cardiopulmonary bypass may affect positioning)

•  Incision usually anterior thoracotomy with partial sternotomy

•  Sequence of surgical events:

1. Structures for lung to be resected are dissected free

2. Pneumonectomy completed

3. Bronchial anastomosis first, PA anastomosis, atrial/pulm vein anastomosis last

4. Pulmonary circulation flushed & ventilation begun

5. Process repeated for other side during bilateral sequential lung transplantation

Specific Anesthetic Considerations

• Lung recipients susceptible to pulm HTN & R ventricular dysfx during 1-lung ventilation

•  Hypoxemia common in 1-lung ventilation; consider using:

• FiO₂ of 100%

• PEEP of 10 as tolerated to dependent lung

• CPAP to nondependent lung

•  Nitric oxide (NO)

• Advantages:

• ↓ pulm vascular resistance & improves oxygenation

• NO preferentially reaches ventilated areas, causing ↑ blood flow, improvements in V./Q. mismatch & improved oxygenation

• ↓ inflammatory response to surgery or trauma

• Impedes microbial growth

• Activates guanylate cyclase in platelets to attenuate platelet aggregation & adhesion

• Disadvantages:

• Methemoglobinemia, NO metabolite–related lung injury, ↓ sensitivity of exhaled N₂O monitoring

• Rapid discontinuation of NO in pulm vasculature prevents systemic vasoconstriction & results in systemic hypotension

•  Cardiopulmonary bypass (CPB) indications

• Adequate oxygenation cannot be maintained despite ventilatory/pharmacologic interventions & PA clamping by surgeons

• Inability to ventilate

• Development of RV dysfx

• CI <2 L/min/m², SvO₂ <60%, MAP <50–60 mm Hg, SaO₂ <85–90%, pH <7

•  May see hypotension with restoration of graft blood flow after anastomosis

•  At end of procedure, eval of pt for tube exchange to single lumen is performed, although high PEEP requirements & oropharyngeal edema may preclude it

ANESTHESIA FOR HEART TRANSPLANTATION

General Information

•  1-yr survival = 87%, 2-yr survival 78% from 1997–2004

•  Poor survival due to paucity of donor organs, devices (e.g., left ventricular-assist devices—LVAD) used to provide a bridge to transplant

Most Common Indications

•  New York Heart Association class III/IV heart failure (despite optimal therapy)

•  Heart failure survival scores high risk

•  Peak VO₂ <10 mL/kg/min after anaerobic threshold

•  Severely symptomatic ventricular arrhythmias refractory to medical, ICD, surgical Tx

• Severely limiting ischemia unresponsive to interventional or surg revascularization

Perioperative Assessment

•  Donor heart function worsens with ischemic time >6 hrs

•  Pt usually not NPO (owing to short notice of graft availability)

•  Pt may receive extensive levels of cardiovascular support

• Meds—warfarin, vasopressor support, ACE inhibitor, dobutamine, milrinone

• Devices—LVAD, pacemaker/AICD, IABP

•  Immunosuppressive meds & antibiotics

•  Ensure blood products available

Intraoperative Management

•  Large-bore IV access, std monitors, preinduction A-line, CVP & PA catheter, TEE

•  Induction and maintenance

• Consider high-dose narcotic rapid sequence induction

• Also etomidate (0.3 mg/kg), fentanyl 1 mcg/kg), succinylcholine (15 mg/kg)

• Neuromuscular blockade with nondepolarizing agent

• May need inotropic support upon induction

• Standard heparin dosing for pre-CPB anticoagulation

• See Chapter 16, Anesthesia for Cardiac Surgery, for detailed notes on CPB

•  Separation from CPB

• Transplanted heart denervated (will not mount tachy-/bradycardic responses)

• Only direct-acting sympathomimetics work for inotropic/chronotropic effects

• Isoproterenol, epinephrine, milrinone, dobutamine

• LV function is generally adequate, however, RV dysfunction often seen

• Strategies to lower PVR

• High FiO₂; avoid hypercapnia/hypothermia

• Optimize airway pressures & tidal volumes

• Use nitrates, PGE1, prostacyclin, & inhaled NO as indicated

• Use CVP/TEE to guide fluid management

• Consider use of RV assist device

Surgical Procedure

•  Incision median sternotomy

•  Aortic cannulation high, near the arch

•  Recipient heart excised (except for L atrial tissue with pulmonary veins)

• Biatrial approach—excises both atria (mandating bicaval anastomosis)

• Classic approach—atria transected at grooves

Specific Anesthetic Considerations

•  Anticipate previous cardiac surgery (redo sternotomy)

• Structures may be adhesed to sternum & ruptured upon entry

• Presence of LVAD/RVAD

•  Pts with hemodynamic instability may need extracorporeal membrane oxygenation (ECMO) prior to induction

•  Immunosuppressive agents need to be given including methylprednisolone 500 mg as last anastomosis is being completed

•  No specific anesthetic strategies for posttransplant anesthesia delivery

• May see a delayed response to catecholamines

• Anticipate a denervated heart with absence of vagal tone