Hemodynamic Changes via the Lung Recruitment Maneuver Can Predict Fluid Responsiveness in Stroke Volume and Arterial Pressure During One-Lung Ventilation

BACKGROUND: We aimed to evaluate the ability of lung recruitment maneuver-induced hemodynamic changes to predict fluid responsiveness in patients undergoing lung-protective ventilation during one-lung ventilation (OLV). METHODS: Thirty patients undergoing thoracic surgery with OLV (tidal volume: 6 mL/kg of ideal body weight and positive end-expiratory pressure: 5 cm H2O) were enrolled. The study protocol began 30 minutes after starting OLV. Simultaneous recordings were performed for hemodynamic variables of heart rate, mean arterial pressure (MAP), stroke volume (SV), pulse pressure variation (PPV), and stroke volume variation (SVV) were recorded at 4 time points: before recruitment maneuver (continuous airway pressure: 30 cm H2O for 30 seconds), at the end of recruitment maneuver, and before and after volume loading (250 mL over 10 minutes). Patients were recognized as fluid responders if the increase in SV or MAP was >10%. Receiver operating characteristic curves for percent decrease in SV and MAP by recruitment maneuver (Delta SVRM and Delta MAP(RM), respectively) were generated to evaluate the ability to discriminate fluid responders from nonresponders. The gray-zone approach was applied for Delta SVRM and Delta MAP(RM). RESULTS: Of 30 patients, there were 17 SV-responders (57%) and 12 blood pressure (BP)-responders (40%). Area under the curve (AUC) for Delta SVRM to discriminate SV-responders from nonresponders was 0.84 (95% confidence interval [CI], 0.67-0.95; P < .001). The best threshold for Delta SVRM to discriminate the SV-responders was -23.7% (95% CI, -41.2 to -17.8; sensitivity, 76.5% [95% CI, 50.1-93.2]; specificity, 84.6% [95% CI, 54.6-98.1]). For BP-responders, AUC for Delta MAP(RM) was 0.80 (95% CI, 0.61-0.92, P < .001). The best threshold for Delta MAP(RM) was -17.3% (95% CI, -23.9 to -5.1; sensitivity, 75.0% [95% CI, 42.8-94.5]; specificity, 77.8% [95% CI, 52.4-93.6]). With the gray-zone approach, the inconclusive range of Delta SVRM for SV-responders was -40.1% to -13.8% including 13 (43%) patients, and that of Delta MAP(RM) was -23.9% to -5.1%, which included 16 (53%) patients. CONCLUSIONS: Delta SVRM and Delta MAP(RM) could predict hemodynamic responses after volume expansion during OLV.