Clinical warning signs for intra-abdominal hypertension in septic shock patients

Background
The latest World Society of the Abdominal Compartment (WSACS) guideline published in 2013 states that risk factors are the most reliable predictors for the diagnosis of intra-abdominal hypertension (IAH) and the bottom line to guide propaedeutic and clinical practice. The objective of this study is to search for clinical, laboratory, and ventilator-associated factors in order to warn medical staff for prompt IAH diagnosis in septic shock patients beyond risk factors simply.

Methods
This is a prospective, observational study, involving all admitted intensive care unit septic shock patients of a single teaching hospital between April and October 2016. All enrolled patients met Sepsis III and Surviving Sepsis Campaign diagnostic criteria. Patients with primary abdominal conditions were excluded, in order to avoid possible bias. Intra-abdominal pressure (IAP) was measured every 6 hours in accordance with WSACS guidelines.

Results
25 sequential patients were included and followed for 10 days after admission. Median age was 51.13 ± 16.52 years old, 64% male. Pulmonary infection was the most frequent etiology of sepsis, representing 76% of the cases. Elevated IAP correlated with higher central venous pressure (CVP) (P = 0.0421); positive end-expiratory pressure (PEEP) (P = 0.0056); elevated airway pressure (P = 0.0015); accumulated fluid balance (P = 0.0273), and elevated SOFA (P = 0.0393) in all septic patients. Reduction of acidosis (P = 0.0096) and increase of serum bicarbonate (P = 0.0247) correlated with lower IAP values.

Conclusions
Elevated CVP, PEEP, SOFA, airway pressure and accumulated fluid balance are correlated with elevated IAP in septic shock patients. Acidosis correction appears to decrease the risk for IAH. Multicentric randomized studies are needed to confirm this hypothesis in a large population.