Incidence/prevalence

• By the end of 2006, there were almost 40 000 people known to be alive with functioning LTs in the USA and over 6000 LTs are performed annually.
  
• Improved long-term survival is possible due to a better understanding of the pathophysiology related to ESLD, improvement in surgical techniques and post-operative care and novel therapeutic approaches.
  
• Immediately after completion of the transplantation operation most patients are transferred to an ICU where optimal post-operative care can only be provided by a dedicated multidisciplinary team.

Pathology/pathogenesis

• Patients with ESLD usually have a marked reduction in systemic vascular resistance, mean arterial pressure and increase in cardiac output. This hyperdynamic stage may last several weeks following LT.
  
• Moreover, myocardial contractility can be impaired due to a decreased number of adrenergic receptors in these patients. The progressive vasodilatation seen in cirrhosis leads to the activation of endogenous vasoconstrictors, sodium and water retention, and increasing renal vasoconstriction.
  
• Patients with cirrhosis usually demonstrate increased total body sodium, and dilutional hyponatremia. Other electrolyte abnormalities are common including hypomagnesemia and hypocalcemia.
  
• Renal perfusion may initially be maintained due to vasodilators such as prostaglandins and nitric oxide. However, the natural progression of liver disease overcomes these protective mechanisms, leading to progressive renal hypoperfusion, a gradual decline in the glomerular filtration rate, and, in some patients, hepatorenal syndrome. Up to 25% of LT candidates have impaired renal function. Continued loss of ascites during the operation and surgical bleeding increases intravascular hypovolemia and the risk of acute kidney injury.
  
• The respiratory system can also been compromised. Mild hypoxemia is common among cirrhotic patients, and can result from the compression of lung parenchyma by ascites or pleural fluid. Severe hypoxemia is less common and, in the absence of associated cardiopulmonary disease, strongly suggests hepatopulmonary syndrome – estimated to be present in 4–47% of patients with chronic liver disease. Hepatic hydrothorax and portopulmonary hypertension are other pulmonary complications that may develop in patients with cirrhosis. During the transplantation surgery, severe lung edema with hypoxemia may occur following reperfusion, or as a consequence of massive release of cytokines due to pre-existing antibodies against blood components causing transfusion-related acute lung injury.
  
• Coagulopathy in ESLD patients results from inadequate clotting factor synthesis, fibrinolysis and thrombocytopenia. Platelet dysfunction is also common in patients with coexisting renal insufficiency.
  
• Most ESLD patients present with hypoalbuminemia and many patients are severely malnourished before transplantation and will require significant nutritional support.

Initial evaluation and general considerations

Physical examination and initial tests

• On arrival in the ICU an initial assessment of the vital signs and complete physical examination must be performed. A chest radiograph is taken to confirm placement of lines and the endotracheal tube position. The nasogastric tube and Foley catheter output must be recorded and if intra-abdominal drains were left, the quantity and the characteristics of the drainage must be determined, whether it is clear, bloody or bilious stained. Patients may arrive hypothermic from the operation room to the ICU and attempts must be done to normalize the body temperature and keep it above 37 °C. Immediate laboratory tests should be ordered including arterial blood gas, CBC, serum electrolytes, glucose, blood urea nitrogen, creatinine, LFTs and serum lactic acid.

Cardiovascular system

• Most patients have a Swan-Ganz catheter and cardiac output and systemic vascular resistance can be calculated. The high cardiac output and low vascular resistance that characterize patients with ESLD can persist for several weeks following transplantation. Hemodynamic stabilization is clinically assessed by adequate organ and tissue perfusion. The intravascular hypovolemic state of these patients requires aggressive volume resuscitation with IV fluids. However, some patients may require vasoconstrictive therapy such as noradrenaline and vasopressin.

Respiratory system

• Pulmonary management consists of standard ventilator support. Some patients with good general condition and functional capacity with uncomplicated surgery can be awakened and extubated in the operating room. However, most of the patients are in a chronic debilitated state and they are typically extubated in the ICU after it has been determined that hemodynamic stability has been achieved and they fulfill the criteria for extubation. In our institution, this occurs most commonly within the first 24 hours after the operation. Patients with intracranial hypertension in the setting of ALF require particular attention to ventilation to prevent abrupt shifts in pressure and the arterial tension of carbon dioxide. Good pain control, chest physiotherapy and incentive spirometry following extubation are mandatory to avoid pulmonary complications.

Renal system

• Prior to transplantation 25% of patients have renal dysfunction and this is an independent predictor of post-transplantation morbidity and mortality. After LT, more than 50% of recipients will show impaired renal dysfunction. Oliguria may be the earliest warning sign. The etiology includes hepatorenal syndrome, perioperative hypotension, acute tubular necrosis, graft dysfunction and drug-induced injury. Those with hepatorenal syndrome are most likely to required renal replacement therapy. The initiation of renal replacement therapy remains a clinical decision where fluid overload, electrolyte disturbances and metabolic acidosis are the most common triggers. Continues venovenous hemodialysis is preferable soon after transplantation because it offers superior cardiovascular stability. If necessary, conventional hemodialysis can be used later. Nephrotoxicity is a known side effect of CNIs used to prevent rejection. Reducing the dose or delaying introduction of CNIs are useful strategies in long-term renal protection in those with a high probability of renal dysfunction.

Electrolytes

• Electrolyte abnormalities are common after transplantation. Hyponatremia is often seen in patients with fluid retention. Rapid correction can result in central pontine myelinolysis and could lead to permanent brain injury. Fluids high in sodium are generally avoided. However, they may be needed in cases of severe hyponatremia. Post-transplantation, fluids should be administered based on the serum sodium level. If the sodium concentration is <125 mEq/L, normal saline (0.9%) should be the fluid of choice. If serum sodium is >135 mg/mEq/L, half normal saline (0.45%) can be used. Plasmalyte solution resembles the electrolyte content of plasma and is often used for resuscitation and maintenance after transplantation. Hypomagnesemia is common in cirrhotic patients and may be exacerbated in the immediate post-operative period by blood loss or medications such as tacrolimus, cyclosporine or loop diuretics and should be corrected. A recovering graft has a high requirement for phosphate and magnesium and these should be replaced adequately. Citrate toxicity from transfusion of blood or blood products may cause a profound reduction in calcium levels. Ionized serum calcium levels should be monitored as total calcium levels depend on the albumin concentration.

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