Incidence, Risk Factors and Outcome Associations of Intra-Abdominal Hypertension in Critically Ill Patients

Abstract

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are significantly associated with morbidity and mortality. We performed a prospective observational study and applied recently published consensus criteria to measure and describe the incidence of IAH and ACS, identify risk factors for their development and define their association with outcomes. We studied 100 consecutive patients admitted to our general intensive care unit. We recorded relevant demographic, clinical data and maximal (max) and mean intra-abdominal pressure (IAP). We measured and defined IAH and ACS using consensus guidelines. Of our study patients, 42% (by IAPmax) and 38% (by IAPmean) had IAH. Patients with IAH had greater mean body mass index (30.4±9.6 vs 25.4±5.6 kg/m2, P=0.005), Acute Physiology and Chronic Health Evaluation III score (78.2±28.5 vs 65.5±29.2, P=0.03) and central venous pressure (12.8±4.8 vs 9.2±3.5 mmHg, P <0.001), lower abdominal perfusion pressure (67.6±13.5 vs 79.3±17.3 mmHg, P <0.001) and lower filtration gradient (51.2±14.8 vs 71.6±17.7 mmHg; P <0.001). Risk factors associated with IAH were body mass index ≥30 (P <0.001), higher central venous pressure (P <0.001), presence of abdominal infection (P=0.005) and presence of sepsis on admission (P=0.035). Abdominal compartment syndrome developed in 4% of patients. IAP was not associated with an increased risk of mortality after adjusting for other confounders. We conclude that, in a general population of critically ill patients, using consensus guidelines, IAH was common and significantly associated with obesity and sepsis on admission. In a minority of patients, IAH was associated with abdominal compartment syndrome. In this cohort IAH was not associated with an increased risk of mortality.

Short-term Effects of Acute Kidney Injury

“…Thus, volume overload may already be seen at early stages of AKI. [46][47][48][49][50][51][52] The major pathophysiologic aspect of fluid overload is interstitial edema, which significantly impairs oxygen and metabolite diffusion, distorts tissue architecture, and obstructs capillary blood flow and lymphatic drainage, resulting in disturbed cell-cell interactions and potentially contributing to progressive organ dysfunction. In encapsulated organs, this process increases interstitial pressure.…”

“…49 Most critically, fluid overload of the lungs results in impaired gas exchange early, often requiring mechanical ventilation, which itself must be seen as a proinflammatory intervention contributing to the systemic inflammatory load of critically ill patients. 50,51 In addition, severe volume overload results in visceral edema, causing intra-abdominal hypertension 52 and potentially even reducing cerebral perfusion pressure (cerebral edema). The definition of volume overload usually relies on increase of body weight or cumulative positive fluid balance compared with baseline.…”

Acute elevation of intra-abdominal pressure contributes to extravascular shift of fluid and proteins in an experimental porcine model

“…Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are known to affect morbidity and mortality in the critically ill patient [1, 2]. Depending on the patient populations, the incidence of IAH has been reported in the range of 32-50% [2–4].…”

“…Depending on the patient populations, the incidence of IAH has been reported in the range of 32-50% [2–4]. …”

“…The occurrence of ACS also varies among specific groups of patients, with an incidence found to be around 4% in a general medical-surgical population [2, 5]. …”