Chapter 87: Cardiopulmonary Complications after Liver Transplantation

BACKGROUND

• Cardiopulmonary complications after orthotopic liver transplantation are common, at rates reported between 25% and 70%, which is higher than for other solid organ transplants.^1–3

• Represents the third leading cause of death behind infection and rejection (22% of all late mortalities).⁴

• Although the principal risk factors for development of these events are the intraoperative transfusion and the patient age, other causes of this higher rate among liver transplant patients remains unknown.

• Most occur within the first 6 months (early) after transplant.

• Attempts to avoid these events are mandatory, mainly because they represent a major source of morbidity and mortality after liver transplantation.

THE TRANSPLANT EVALUATION TEAM

• Cardiovascular events posttransplantation should be evaluated by a skilled multidisciplinary team, including the cardiology and pulmonology team.

• Risks, benefits, and the process from preoperative evaluation to postoperative evaluation and long-term follow-up should be reviewed with the patient (when appropriate) and the family/caregivers in each step in order to determine whether to proceed or not based on an informed decision.

PREDICTIVE RISK FACTORS ASSOCIATED WITH CARDIOVASCULAR COMPLICATIONS

• Pretransplant factors:^5,6

  • Recipient’s age⁷

  • Hypercholesterolemia

  • Systolic hypertension

  • Severe ascites

  • Metabolic disturbances before liver transplant

  • Hyponatremia

  • Hyperhomocysteinemia

  • Severity of liver dysfunction (high integrated Model for End-Stage Liver Disease [MELD] score, high MELD-Na score, high MELD score)

  • Diastolic dysfunction (low E/A ratio and prolonged EDT)⁸

  • Elevated serum troponin levels

  • Elevated blood urea nitrogen (BUN)

  • Elevated brain natriuretic peptide (BNP)

  • Abnormal spirometry findings

  • Chronic alcohol consumption

  • Smoking history

  • Acute renal failure

  • Mechanical ventilation due to severe respiratory failure

  • High values of international normalized ratio (INR)

  • Deceased donor source of organ transplantation

  • Cirrhotic encephalopathy

  • Cardiac disease history:

    • Coronary artery disease (CAD)

    • Coronary artery bypass graft (CABG)

    • Valvulopathy

    • Percutaneous transluminal coronary angioplasty with stent placement (PTCA-STENT)

• Major intraoperative risk factors:

  • Surgical procedure^9,10

  • Intraoperative fluid transfusion volume^9,11,12

  • Intraoperative blood transfusion volume^11,13

  • Perioperative fluid balance¹¹

  • Intraoperative fluid retention¹⁴

  • Intraoperative bleeding volumes¹⁴

• Posttransplant factors:

  • Surgical ischemic times

  • Graft quality

  • Amount of intraoperative transfused blood and plasma

  • Decreased high-density lipoprotein cholesterol (HDL-C)

  • Renal impairment

  • Concomitant cardiopulmonary toxic drugs

  • Excessive perioperative fluid administration⁹

  • Delayed weaning from mechanical ventilation^9,10,15

  • Acute rejection during the hospital stay⁹

  • Postoperative acute renal failure¹⁶

  • Postoperative hypoproteinemia

  • Onset of renal insufficiency

  • Poor postoperative myocardial function

  • Right hemidiaphragm paralysis¹⁷

  • Greater exposure to nosocomial agents¹⁸

  • Significant decline in the recipient’s immune function¹⁸

  • Surgical complications¹⁸

  • Reinterventions or need for retransplantation¹⁸

MANAGEMENT

• Prevention:⁵

  • Preoperative strategies:

    • Pulmonary rehabilitation prior to orthoptic liver transplant (OLT)

  • Intraoperative strategies:

    • Reduction in the degree of surgical insult

    • Reduction in the level of aggressiveness

    • Reduction in the duration of the procedure

    • Reduction in the amount of blood lost

  • Postoperative strategies:

    • Early extubation

    • Adequate postoperative pain relief

    • Optimal hemodynamic and fluid management

    • Improvement of general health and nutrition

    • Lung expansion maneuvers

    • Deep breathing ...