The risk factors for intra-abdominal hypertension in a mixed population of critically ill patients

The intra-abdominal pressure (IAP) is an important indicator of the patient's physiologic status because even a slight increase of IAP can have deleterious effects.

The aim of this study was to evaluate in all the new patients admitted to general ICUs, during 4 weeks, the incidence of IAP and the possible associated risk factors.

At admission, the APACHE II score, etiologic factors (abdominal surgery, hemoperitoneum, abdominal infection, massive fluid resuscitation, ileus, pneumonia and bacteraemia), predisposing conditions (acidosis, polytransfusion, coagulopathy, sepsis and liver dysfunction) and type of admission were evaluated. The IAP was measured twice every day for 7 days, or less if the patient was ICU-discharged or death occurred.

Two hundred and sixty-five patients were enrolled from 13 ICUs: mean age 62.8 ± 17.7 years, body mass index 25.9 ± 17.7 kg/m², APACHE II 17.8 ± 8.7, IAP 9.7 ± 5.0 mmHg, medical patients 132 (49.8%), surgical patients 71 (26.8%), emergency patients 42 (15.8%), trauma patients 20 (7.6%); 62 patients died in the ICU (23.4%). Intra-abdominal hypertension (IAH) was classified as a mean IAP of 12 mmHg or more at admission. There were 80 (30.2%) patients with IAH and 185 (69.8%) without IAH.

The only independent risk factors present at admission significantly related to IAH were the number of organ failures (odds ratio [OR] = 1.5, confidence interval [CI] = 1.1-2.0), the abdominal surgery (OR = 2.6, CI = 1.4-5.1), ileus (OR = 2.6, CI = 1.4-4.7) and liver dysfunction (OR = 3.2, CI = 1.6-6.5).

These data suggest that either an abdominal problem or the number of organ failures are associated with the IAH.