Postoperative intra-abdominal Pressure and renal Function After Liver Transplantation

Hypothesis Intra-abdominal hypertension frequently threatens renal function early after orthotopic liver transplantation (OLT). Design A prospective study of consecutive patients who underwent OLT. Setting The intensive care unit of a National Health Service teaching hospital. Patients and Main Outcome Measures The intra-abdominal pressure (IAP) of 108 consecutive patients who underwent OLT was postoperatively measured 3 times a day for 72 hours using the urinary bladder technique. Intra-abdominal hypertension was defined as an IAP of 25 mm Hg or higher. Results Thirty-four patients (31%) had a high IAP. Acute renal failure developed in 17 recipients (16%), 11 (65%) of whom had intra-abdominal hypertension (P<.01), with a mean ± SD IAP of 27.9 ± 9.9 mm Hg vs 18.6 ± 5.2 mm Hg in those without acute renal failure (P<.001). The subjects with a high IAP were more frequently administered loop diuretics to maintain adequate diuresis (P<.001) and had a low mean arterial pressure on the day of surgery (P<.01), despite the fact that they were given more intravenous fluids (P<.01) and did not differ in the need for inotropic drugs. Logistic regression analysis showed that intraoperative transfusions of more than 15 U, respiratory failure, and intra-abdominal hypertension (P<.01) were independent risk factors for renal failure. The length of intensive care unit stay was similar in the patients with a normal and a high IAP, but mortality was higher among the latter (P = .02). Conclusions Intra-abdominal hypertension is common after OLT and is significantly associated with renal failure, reduced urinary output, and intensive care unit mortality. It is, therefore, worth monitoring IAP in those undergoing OLT. ALTHOUGH THE measurement of intra-abdominal pressure (IAP) is not new, its importance for critically ill patients is still under investigation. The association between renal impairment and increased IAP was first reported in 1876,8 but little attention was given to it and our understanding of the clinical significance of IAP remained poor until the second half of the past century, when numerous studies6- 7 revealed the deleterious effects of high IAP on almost every organ and function within the abdominal cavity. Evidence of the clinical importance of intra-abdominal hypertension (IAH) has increased more recently, but, possibly because of some skepticism concerning its value, IAP is still not routinely measured in critically ill patients. Subjects undergoing orthotopic liver transplantation (OLT) are at risk for IAH not only because of the pathophysiological features of the chronic liver disease (tense ascites)14 but also because of the particular characteristics of transplantation (intra-abdominal hemorrhaging leading to the accumulation of blood and clots, the use of perihepatic or retroperitoneal packs to control nonsurgical bleeding, bowel edema or congestion due to portal hypertension or massive fluid resuscitation, and the use of pneumatic antishock garments). The renal function of patients undergoing OLT may be frequently threatened by an impending hepatorenal syndrome, problems of hydroelectrolytic homeostasis, or the frequent use of diuretics and nephrotoxic drugs; once renal failure is established, it severely affects patient outcome. Given that, to the best of our knowledge, there is no published article concerning the relationship between IAH and renal function in subjects undergoing OLT. This study investigates the possible association between increased IAP and renal function impairment in the days immediately following OLT.