Abstract

Background: Septic and hypovolemic shock are fatal conditions requiring prompt diagnosis and treatment. Differentiating between them at the bedside remains understudied. While lactate testing can help detect septic shock, its role in hypovolemic shock is unclear. This study assessed lactate changes in diarrheal patients with septic and hypovolemic shock post-fluid resuscitation.

Methods: A 19-month prospective observational study was conducted at the emergency ward of Dhaka Hospital, icddr,b, from October 2021 to May 2023, enrolling critically ill diarrheal adults 18 years). Patients with poor perfusion or hypotension due to septic shock (cases) and severe dehydration-induced hypovolemic shock (comparison group) were studied. POC lactate levels were measured at hours 0, 1, and 6 using StatStrip Lactate meters. Paired t-tests and odds ratios (OR) assessed lactate dynamics and associations. The study was approved by ethics committees (PR-21097) and registered (NCT05108467).

Findings: Among 435 patients, 135 had septic shock, 141 had hypovolemic shock, and 41 responded to fluid bolus. Mortality in the septic shock group was 25%, with none in the hypovolemic shock group. Patients from outside Dhaka had higher septic shock prevalence (55% vs. 28%; p<0.001). POC lactate levels significantly differed between groups at all time points: hour 0 (OR: 1.07; p=0.039), hour 1 (OR: 1.48; p<0.001), and hour 6 (OR: 2.36; p<0.001). The gradient between hours 1 and 2 also differed (OR: 0.74; p<0.001).

Interpretation: POC lactate testing effectively distinguishes septic shock from hypovolemic shock, enabling timely and reliable diagnosis and treatment of life-threatening conditions.

Keywords: Adults, Diarrhea, Hypovolemic Shock, POC Lactate Test, Mortality, Septic Shock