Volume Overload: Prevalence, Risk Factors, and Functional Outcome in Survivors of Septic Shock

Survivors of septic shock have impaired functional status. Volume overload is associated with poor outcomes in patients with septic shock, but the impact of volume overload on functional outcome and discharge destination of survivors is unknown.

This study describes patterns of fluid management both during and after septic shock. We examined factors associated with volume overload upon intensive care unit (ICU) discharge. We then examined associations between volume overload upon ICU discharge, mobility limitation, and discharge to a healthcare facility in septic shock survivors, with the hypothesis that volume overload is associated with increased odds of these outcomes.

We retrospectively reviewed the medical records of 247 patients admitted with septic shock to an academic county hospital between June 2009 and April 2012 who survived to ICU discharge. We defined volume overload as a fluid balance expected to increase the subject's admission weight by 10%. Statistical methods included unadjusted analyses and multivariable logistic regression.

Eighty-six percent of patients had a positive fluid balance, and 35% had volume overload upon ICU discharge. Factors associated with volume overload in unadjusted analyses included more severe illness, cirrhosis, blood transfusion during shock, and higher volumes of fluid administration both during and after shock. Blood transfusion during shock was independently associated with increased odds of volume overload (odds ratio [OR], 2.65; 95% confidence interval [CI], 1.33-5.27; P = 0.01) after adjusting for preexisting conditions and severity of illness. Only 42% of patients received at least one dose of a diuretic during their hospitalization. Volume overload upon ICU discharge was independently associated with inability to ambulate upon hospital discharge (OR, 2.29; 95% CI, 1.24-4.25; P = 0.01) and, in patients admitted from home, upon discharge to a healthcare facility (OR, 2.34; 95% CI, 1.1-4.98; P = 0.03).

Volume overload is independently associated with impaired mobility and discharge to a healthcare facility in survivors of septic shock. Prevention and treatment of volume overload in patients with septic shock warrants further investigation.