Evaluation of end-tidal carbon dioxide gradient as a predictor of volume responsiveness in spontaneously breathing healthy adults

Abstract

BackgroundMethods to guide fluid therapy in spontaneously breathing patients are scarce. No studies have reported the accuracy of end-tidal CO2 (ET-CO2) to predict volume responsiveness in these patients. We sought to evaluate the ET-CO2 gradient (ΔET-CO2) after a passive leg rise (PLR) maneuver to predict volume responsiveness in spontaneously breathing healthy adults.MethodsWe conducted a prospective study in healthy adult human volunteers. A PLR maneuver was performed and cardiac output (CO) was measured by transthoracic echocardiography. ET-CO2 was measured with non-invasive capnographs. Volume responsiveness was defined as an increase in cardiac output (CO) > 12% at 90 s after PLR.ResultsOf the 50 volunteers, 32% were classified as volume responders. In this group, the left ventricle outflow tract velocity time integral (VTILVOT) increased from 17.9 ± 3.0 to 20.4 ± 3.4 (p = 0.0004), CO increased from 4.4 ± 1.5 to 5.5 ± 1.6 (p = 0.0), and ET-CO2 rose from 32 ± 4.84 to 33 ± 5.07 (p = 0.135). Within the entire population, PLR-induced percentage ∆CO was not correlated with percentage ∆ET-CO2 (R2 = 0.13; p = 0.36). The area under the receiver operating curve for the ability of ET-CO2 to discriminate responders from non-responders was of 0.67 ± 0.09 (95% CI 0.498–0.853). A ΔET-CO2 ≥ 2 mmHg had a sensitivity of 50%, specificity of 97.06%, positive likelihood ratio of 17.00, negative likelihood ratio of 0.51, positive predictive value of 88.9%, and negative predictive value of 80.5% for the prediction of fluid responsiveness.ConclusionsΔET-CO2 after a PLR has limited utility to discriminate responders from non-responders among healthy spontaneously breathing adults.Electronic supplementary materialThe online version of this article (10.1186/s40635-018-0187-0) contains supplementary material, which is available to authorized users.

Change in left ventricular velocity time integral during Trendelenburg maneuver predicts fluid responsiveness in cardiac surgical patients in the operating room

“…Monnet et al reported that a PLR-induced increase in EtCO 2 ≥5% predicted a fluid induced increase in CI ≥15% with an AUC of 0.93 (0.81-0.99), a sensitivity of 71 % and a specificity of 100%. In contrast to the above findings, Arango-Granados et al reported that variation in EtCO 2 after PLR has limited utility to discriminate fluid responders among healthy spontaneously breathing adults (32). In the current study, the changes in EtCO 2 induced by TP (ΔEtCO 2 -TP) could not predict fluid responsiveness with an AUC of 0.532 (95% CI: 0.391-0.674).…”

Assessment of Fluid Responsiveness With End Tidal Carbon Dioxide Using A Simplified LegRaising Maneuver in Non-Cardiac Patients Admitted in Medical Intensive Care Unit

“…Granados et al, in their study concluded that mean arterial pressure was significantly different in the responders and non-responders of PLR maneuver. 21 Illyas et al, in a local study concluded that mean arterial pressure has no relationship with hemody-namic response. 12 Our results supported the results of Granados et al…”

Use of noninvasive volume assessment methods to predict acute blood loss in spontaneously breathing volunteers

“…There was a significant increase in the delta EtCO2 in the volume responded group (5.9±7.6% vs. 1.4±4.4%, P=0.02). A similar study by Arango-Granados et al [ 12 ] evaluated the predictive ability of delta EtCO2 for PLR-induced volume responsiveness in spontaneously breathing volunteers and reported a weak correlation of PLR-induced changes in cardiac output (CO) with delta EtCO2. In our study, we observed a significant postdonation and post-PLR decrease and increase, respectively, in the mean EtCO2.…”

“…10 End-tidal carbon dioxide (EtCO2) is an important metabolism indicator that could be used to assess various conditions of critically ill patients, including volume status and responsiveness. 11,12 EtCO2 utility in noninvasive monitoring of patients in shock has been reported 13 ; however, there have been few studies on EtCO2 accuracy in early-stage hypovolemia. 14,15 Previous studies have reported the role of the vena cava collapsibility index (VCCI) in volume status prediction.…”