INTRA‐ABDOMINAL PRESSURE AND RENAL FUNCTION AFTER SURGERY TO THE ABDOMINAL AORTA

Abstract

It has been suggested that an elevated intra‐abdominal pressure (IAP) can impair renal function. In a prospective longitudinal study, the IAP of 42 patients admitted to an intensive care unit after abdominal aortic surgery was monitored. When compared with the other patients, the 22 patients (53%) who developed renal impairment had higher IAP (17.8 ± 6.0 mmHg versus 14.1 ± 4.8 mmHg: P < 0.01) and APACHE II scores (15.6 ± 6.0 versus 9.8 ± 4.6; P < 0.01). Each of the 10 patients who were re‐explored because of haemodynamic instability and oliguria had an IAP of > 18 mmHg (positive predictive value = 85%, negative predictive value = 62%). Following re‐exploration, the urinary output increased by 115 ± 40 mL/h (P < 0.01), and the IAP decreased by 10 ± 3 mmHg (P < 0.01). Although it is concluded that an IAP > 18 mmHg is a significant risk factor for the development of impaired renal function, it was not possible to prove a causal relationship between these events. Nevertheless, such a relationship has been demonstrated in animal and human models.