Evaluation of passive leg raising test for predicting fluid responsiveness in shock patients

Abstract

Introduction: Intravenous fluid administration remains the primary therapeutic intervention for haemodynamically unstable patients. However, studies have shown that about 50% of such patients would not respond to fluid therapy only. This study evaluates the predictive value of passive leg raising (PLR) test in predicting fluid responsiveness in shock patients.

Methods: Adult patients who were in a state of continuous shock (systolic blood pressure < 90mmHg) after initial fluid resuscitation in accident and emergency unit in a teaching hospital in Nigeria over a six-month period were enrolled.  All the patients underwent passive leg raising (PLR) test, and were then divided into PLR responders (systolic blood pressure >90mmHg) and PLR non-responders (systolic blood pressure <90mmHg) following PLR. This was followed by further re-categorization into two sub-groups; those who responded to fluid therapy to maintain blood pressure (FTG) and those who required cardiotonic drugs (CTG). The pre-intervention and post-intervention vital signs were then retrospectively analysed between the groups.

Results: Twenty-five patients’ results were analysed for the study. The mean age of the patients was 50.6±4.64 years with male to female ratio of 1.2:1. The mean age of the patients in FTG and CTG were comparable (51.67±3.54 vs49.53±5.28; p= 0.2378). Twelve patients responded to Passive Leg Raising (PLR) test and 13 patients failed to respond to PLR. Nine (75%) out of 12 patients that responded to PLR were successfully managed with fluid therapy as compared to 2 (15.38%) out of 13 non-responders who were successfully managed with fluid therapy only (p=0.0094) giving PLR  75% and 85% positive predictive value and negative predictive value respectively in predicting pre-load dependent circulation.

Conclusion: Passive leg rising can be used as a guide for fluid replacement in patients with shock. Other interventions should be considered early in patients who failed to respond to passive leg raising.