Comparison of Predictive Value of End-Expiratory Occlusion Test and Passive Leg Raising in Predicting Fluid Responsiveness in Postoperative Patients

Abstract

Background: Fluid management in postoperative patients is challenging due to physiological changes, surgical stress, and comorbidities. Accurate prediction of fluid responsiveness (FR) is essential to avoid complications from under- or over-resuscitation. Objectives: The present study compared the predictive value of two non-invasive methods — the end-expiratory occlusion (EEO) test and the passive leg raising (PLR) test — in assessing FR in mechanically ventilated postoperative patients. Methods: This prospective, non-randomized, interventional study enrolled 31 mechanically ventilated critically ill postoperative patients. Hemodynamic monitoring was performed using the PiCCO system. Baseline parameters were recorded (T0), followed by a 30-second EEO test (T1). After a 5-minute recovery period (T2), a 90-second PLR test was conducted (T3). Patients subsequently received 500 mL of crystalloid solution over 30 minutes, and post-infusion hemodynamic measurements were obtained (T4). Positive FR was defined as a Cardiac Index (CI) ≥ 15% increase in CI at T4 compared to T0. Results: Among the 31 patients, 24 (77.4%) were fluid responsive. Neither EEO nor PLR significantly altered heart rate; however, both increased blood pressure (EEO: 6.7 ± 5.86 mm Hg, PLR: 8.9 ± 8.7 mm Hg) and cardiac output (EEO: 8 ± 3%, PLR: 15 ± 6%). The EEO-induced ΔCI predicted positive FR with an area under the curve (AUC) of 0.898, a sensitivity of 95.8%, a specificity of 85.7%, and a cutoff of 5.3%. The PLR-induced ΔCI yielded an AUC of 0.786, a sensitivity of 66.6%, a specificity of 100%, and a cutoff value of 13.4%. No significant difference in FR prediction was observed between the two methods (P > 0.05). Conclusions: Both EEO and PLR demonstrate high predictive value for FR in postoperative patients. Although PLR induced greater hemodynamic changes than EEO, their predictive capacities were comparable.