Ability of short-time low peep challenge to predict fluid responsiveness in mechanically ventilated patients in the intensive care

Abstract

Short-time low PEEP challenge (SLPC, application of additional 5 cmH 2 O PEEP to patients for 30 s) is a novel functional hemodynamic test presented in the literature. We hypothesized that SLPC could predict fluid responsiveness better than stroke volume variation (SVV) in mechanically ventilated intensive care patients. Heart rate, mean arterial pressure, stroke volume index (SVI) and SVV were recorded before SLPC, during SLPC and before and after 500 mL fluid loading. Patients whose SVI increased more than 15% after the fluid loading were defined as fluid responders. Reciever operating characteristics (ROC) curves were generated to evaluate the abilities of the methods to predict fluid responsiveness. Fifty-five patients completed the study. Twenty-five (46%) of them were responders. Decrease percentage in SVI during SLPC (SVIΔ%-SLPC) was 11.6 ± 5.2% and 4.3 ± 2.2% in responders and non-responders, respectively (p < 0.001). A good correlation was found between SVIΔ%-SLPC and percentage change in SVI after fluid loading (r = 0.728, P < 0.001). Areas under the ROC curves (ROC-AUC) of SVIΔ%-SLPC and SVV were 0.951 (95% CI 0.857-0.991) and 0.747 (95% CI 0.611-0.854), respectively. The ROC-AUC of SVIΔ%-SLPC was significantly higher than that of SVV (p = 0.0045). The best cut-off value of SVIΔ%-SLPC was 7.5% with 90% sensitivity and 96% specificity. The percentage change in SVI during SLPC predicts fluid responsiveness in intensive care patients who are ventilated with low tidal volumes; the sensitivity and specificity values are higher than those of SVV.

The increase in cardiac output induced by a decrease in positive end-expiratory pressure reliably detects volume responsiveness: the PEEP-test study

“…A study in critically ill patients showed that the response of stroke volume to a systematic increase in PEEP by 5 cmH 2 O for 30 seconds detected uid responsiveness [24]. Our results con rm that volume responsiveness can be assessed by manipulating PEEP.…”

“…The latter study was conducted mainly in postoperative patients. Accordingly, the PEEP at baseline was low (6 cmH 2 O) [24]. Our study was conducted in a wider population of patients with circulatory failure.…”

“…In particular, by increasing the intrathoracic pressure, which surrounds the cardiac chambers, it may decrease cardiac preload and cardiac output [22,23]. In this connection, a transient increase in PEEP was proposed as a volume responsiveness test in patients without low lung compliance and ventilated with a low level of PEEP [24,25]. In patients ventilated with high levels of PEEP and altered lung compliance, increasing PEEP further could lead to misleading results due potential increase in the right ventricular afterload [22].…”

Individualizing Fluid Management in Patients with Acute Respiratory Distress Syndrome and with Reduced Lung Tissue Due to Surgery—A Narrative Review

“…Further tests may be used in routine: end-expiratory occlusion test (15 s lasting expiratory hold leading to increased stroke volume by 10% [ 38 ]). PEEP induced a decrease in flow parameters (14% decrease in stroke volume after the increase in PEEP by 5 cm H 2 O [ 39 ]). Some degree of fluid responsiveness may be diagnosed by performing lung recruitment—a 30% drop of stroke volume after 30 s lasting 30 cm H 2 O recruitment maneuver [ 40 ].…”

The increase in cardiac output induced by a decrease in positive end-expiratory pressure reliably detects volume responsiveness: the PEEP-test study

“…In mechanically ventilated patients, positive end-expiratory pressure (PEEP) has a two-fold effect [ 13 ]: on the one hand it may increase the pulmonary vascular resistance and the right ventricular afterload by increasing the transpulmonary pressure, and on the other hand by increasing the intrathoracic pressure, it may decrease cardiac preload [ 14 , 15 ]. Considering the latter effect, a transient increase in PEEP was proposed as a volume responsiveness test in ventilated patients without low lung compliance and a low PEEP level [ 16 , 17 ]. However, in patients ventilated with high levels of PEEP and low lung compliance, the test reliability may be impaired, because increasing PEEP further may significantly increase the right ventricular afterload [ 14 ], altering the effects of PEEP changes on cardiac output.…”