Risk factors for intra-abdominal hypertension in mechanically ventilated patients.

BACKGROUND: Intra-abdominal hypertension (IAH) in intensive care patients is associated with an adverse outcome, but the risk factors for development of IAH have not been extensively studied. We aimed to identify independent risk factors for IAH in mechanically ventilated (MV) patients.
METHODS: In this prospective observational study, 563 MV patients staying in the general intensive care unit (ICU) of a university hospital for more than 24 h were observed during their ICU stay. Repeated intermittent measurements of intra-abdominal pressure (IAP) via the urinary bladder were performed.
RESULTS: IAH (sustained or repeated IAP≥12 mmHg) developed in 182 patients (32.3%). From all the study patients, 44.4% had a primary pathology in the abdomino-pelvic region. Two thirds of all IAH cases developed in this group. Obesity [body mass index (BMI)>30], high positive end-expiratory pressure (PEEP>10), respiratory failure (PaO(2)/FiO(2) <300), use of vasopressors/inotropes, pancreatitis, hepatic failure/cirrhosis with ascites, gastrointestinal bleeding and laparotomy on admission day were identified as independent risk factors for IAH. None of the patients without any of these risk factors (26 patients) developed IAH.
CONCLUSION: The precise prediction of development IAH in mixed ICU population remains difficult. In the absence of BMI>30, PEEP>10 cmH(2)O, PaO(2)/FiO(2) <300, use of vasopressors/inotropes, pancreatitis, hepatic failure/cirrhosis with ascites, gastrointestinal bleeding and laparotomy on admission day, the risk for development of IAH in MV ICU patients is minimal.