End-Expiratory Occlusion Test to Predict Fluid Responsiveness Is Not Suitable for Laparotomic Surgery

Assessment of fluid responsiveness using pulse pressure variation, stroke volume variation, plethysmographic variability index, central venous pressure, and inferior vena cava variation in patients undergoing mechanical ventilation: a systematic review and meta-analysis

IMPORTANCE

Maneuvers assessing fluid responsiveness before an intravascular volume expansion may limit useless fluid administration, which in turn may improve outcomes.

OBJECTIVE

To describe maneuvers for assessing fluid responsiveness in mechanically ventilated patients.

REGISTRATION

The protocol was registered at PROSPERO: CRD42019146781.

INFORMATION SOURCES AND SEARCH

PubMed, EMBASE, CINAHL, SCOPUS, and Web of Science were search from inception to 08/08/2023.

STUDY SELECTION AND DATA COLLECTION

Prospective and intervention studies were selected.

STATISTICAL ANALYSIS

Data for each maneuver were reported individually and data from the five most employed maneuvers were aggregated. A traditional and a Bayesian meta-analysis approach were performed.

RESULTS

A total of 69 studies, encompassing 3185 fluid challenges and 2711 patients were analyzed. The prevalence of fluid responsiveness was 49.9%. Pulse pressure variation (PPV) was studied in 40 studies, mean threshold with 95% confidence intervals (95% CI) = 11.5 (10.5-12.4)%, and area under the receiver operating characteristics curve (AUC) with 95% CI was 0.87 (0.84-0.90). Stroke volume variation (SVV) was studied in 24 studies, mean threshold with 95% CI = 12.1 (10.9-13.3)%, and AUC with 95% CI was 0.87 (0.84-0.91). The plethysmographic variability index (PVI) was studied in 17 studies, mean threshold = 13.8 (12.3-15.3)%, and AUC was 0.88 (0.82-0.94). Central venous pressure (CVP) was studied in 12 studies, mean threshold with 95% CI = 9.0 (7.7-10.1) mmHg, and AUC with 95% CI was 0.77 (0.69-0.87). Inferior vena cava variation (∆IVC) was studied in 8 studies, mean threshold = 15.4 (13.3-17.6)%, and AUC with 95% CI was 0.83 (0.78-0.89).

CONCLUSIONS

Fluid responsiveness can be reliably assessed in adult patients under mechanical ventilation. Among the five maneuvers compared in predicting fluid responsiveness, PPV, SVV, and PVI were superior to CVP and ∆IVC. However, there is no data supporting any of the above mentioned as being the best maneuver. Additionally, other well-established tests, such as the passive leg raising test, end-expiratory occlusion test, and tidal volume challenge, are also reliable.

Reliability of pulse pressure and stroke volume variation in assessing fluid responsiveness in the operating room: a metanalysis and a metaregression

BACKGROUND

Pulse pressure and stroke volume variation (PPV and SVV) have been widely used in surgical patients as predictors of fluid challenge (FC) response. Several factors may affect the reliability of these indices in predicting fluid responsiveness, such as the position of the patient, the use of laparoscopy and the opening of the abdomen or the chest, combined FC characteristics, the tidal volume (Vt) and the type of anesthesia.

METHODS

Systematic review and metanalysis of PPV and SVV use in surgical adult patients. The QUADAS-2 scale was used to assess the risk of bias of included studies. We adopted a metanalysis pooling of aggregate data from 5 subgroups of studies with random effects models using the common-effect inverse variance model. The area under the curve (AUC) of pooled receiving operating characteristics (ROC) curves was reported. A metaregression was performed using FC type, volume, and rate as independent variables.

RESULTS

We selected 59 studies enrolling 2,947 patients, with a median of fluid responders of 55% (46-63). The pooled AUC for the PPV was 0.77 (0.73-0.80), with a mean threshold of 10.8 (10.6-11.0). The pooled AUC for the SVV was 0.76 (0.72-0.80), with a mean threshold of 12.1 (11.6-12.7); 19 studies (32.2%) reported the grey zone of PPV or SVV, with a median of 56% (40-62) and 57% (46-83) of patients included, respectively. In the different subgroups, the AUC and the best thresholds ranged from 0.69 and 0.81 and from 6.9 to 11.5% for the PPV, and from 0.73 to 0.79 and 9.9 to 10.8% for the SVV. A high Vt and the choice of colloids positively impacted on PPV performance, especially among patients with closed chest and abdomen, or in prone position.

CONCLUSION

The overall performance of PPV and SVV in operating room in predicting fluid responsiveness is moderate, ranging close to an AUC of 0.80 only some subgroups of surgical patients. The grey zone of these dynamic indices is wide and should be carefully considered during the assessment of fluid responsiveness. A high Vt and the choice of colloids for the FC are factors potentially influencing PPV reliability.

TRIAL REGISTRATION

PROSPERO (CRD42022379120), December 2022. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=379120.

Predictors of fluid responsiveness in the operating room: a narrative review

Prediction of fluid responsiveness has been considered an essential tool for modern fluid management. However, most studies in this field have focused on patients in intensive care unit despite numerous research throughout several decades. Therefore, the present narrative review aims to show the representative method's feasibility, advantages, and limitations in predicting fluid responsiveness, focusing on the operating room environments. Firstly, we described the predictors of fluid responsiveness based on heart-lung interaction, including pulse pressure and stroke volume variations, the measurement of respiratory variations of inferior vena cava diameter, and the end-expiratory occlusion test and addressed their limitations. Subsequently, the passive leg raising test and mini-fluid challenge tests were also mentioned, which assess fluid responsiveness by mimicking a classic fluid challenge. In the last part of this review, we pointed out the pitfalls of fluid management based on fluid responsiveness prediction, which emphasized the importance of individualized decision-making. Understanding the available representative methods to predict fluid responsiveness and their associated benefits and drawbacks through this review will aid anesthesiologists in choosing the most reliable methods for optimal fluid administration in each patient during anesthesia in the operating room.

Prediction of fluid responsiveness. What’s new?

Although the administration of fluid is the first treatment considered in almost all cases of circulatory failure, this therapeutic option poses two essential problems: the increase in cardiac output induced by a bolus of fluid is inconstant, and the deleterious effects of fluid overload are now clearly demonstrated. This is why many tests and indices have been developed to detect preload dependence and predict fluid responsiveness. In this review, we take stock of the data published in the field over the past three years. Regarding the passive leg raising test, we detail the different stroke volume surrogates that have recently been described to measure its effects using minimally invasive and easily accessible methods. We review the limits of the test, especially in patients with intra-abdominal hypertension. Regarding the end-expiratory occlusion test, we also present recent investigations that have sought to measure its effects without an invasive measurement of cardiac output. Although the limits of interpretation of the respiratory variation of pulse pressure and of the diameter of the vena cava during mechanical ventilation are now well known, several recent studies have shown how changes in pulse pressure variation itself during other tests reflect simultaneous changes in cardiac output, allowing these tests to be carried out without its direct measurement. This is particularly the case during the tidal volume challenge, a relatively recent test whose reliability is increasingly well established. The mini-fluid challenge has the advantage of being easy to perform, but it requires direct measurement of cardiac output, like the classic fluid challenge. Initially described with echocardiography, recent studies have investigated other means of judging its effects. We highlight the problem of their precision, which is necessary to evidence small changes in cardiac output. Finally, we point out other tests that have appeared more recently, such as the Trendelenburg manoeuvre, a potentially interesting alternative for patients in the prone position.

Changes in peripheral perfusion index during intraoperative end-expiratory occlusion tests do not predict the response to fluid administration in patients undergoing lung protective ventilation

INTRODUCTION

The end-expiratory occlusion test (EEOT) may predict the response to fluid administration in patients undergoing lung-protective ventilation, but arterial catheter insertion is necessary to evaluate changes in stroke volume (SV). The peripheral perfusion index is a potential noninvasive alternative to evaluate SV. The aim of this study is to investigate whether changes in perfusion index during an intraoperative EEOT can predict the response to fluid administration in patients undergoing lung-protective ventilation (tidal volume 7 ml/kg predicted body weight).

METHODS

Forty-one elective surgical patients were enrolled. The SV and perfusion index were recorded before (baseline), during a 40-s EEOT and after volume expansion (250 ml of lactated Ringer's solution over 10 min). Patients with an increase in SV greater than 10% after volume expansion were defined as responders. ΔPI (change in perfusion index between baseline and 20 (ΔPI₂₀) or 40 s (ΔPI₄₀) after the beginning of EEOT were calculated using: ΔPI₂₀ (%) = [(PI at 20 s after EEOT beginning - PI_baseline)/PI_baseline] × 100, ΔPI₄₀ (%) = [(PI at 40 s after EEO beginning - PI_baseline)/PI_baseline] × 100).

RESULTS

Sixteen patients were responders, and 25 were non-responders. The area under the receiver operating characteristics curves generated for ΔPI₂₀ and ΔPI₄₀ to predict response to a fluid challenge were 0.561 (95% CI 0.374-0.749) and 0.688 (95% CI 0.523-0.852), respectively.

CONCLUSION

Changes in perfusion index during intraoperative EEOT in patients undergoing lung-protective ventilation (7 ml/kg) were unable to predict the response to fluid administration.

Mini fluid chAllenge aNd End-expiratory occlusion test to assess flUid responsiVEness in the opeRating room (MANEUVER study): A multicentre cohort study

BACKGROUND

The fluid challenge response in surgical patients can be predicted by functional haemodynamic tests. Two tests, the mini-fluid challenge (mini-FC) and end-expiratory occlusion test (EEOT), have been assessed in a few small single-centre studies with conflicting results. In general, functional haemodynamic tests have not performed reliably in predicting fluid responsiveness in patients undergoing laparotomy.

OBJECTIVE

This trial is designed to address and compare the reliability of the EEOT and the mini-FC in predicting fluid responsiveness during laparotomy.

DESIGN

Prospective, multicentre study.

SETTING

Three university hospitals in Italy.

PATIENTS

A total of 103 adults patients scheduled for elective laparotomy with invasive arterial monitoring.

INTERVENTIONS

The study protocol evaluated the changes in the stroke volume index (SVI) 20 s (EEOT20) and 30 s (EEOT30) after an expiratory hold and after a mini-FC of 100 ml over 1 min. Fluid responsiveness required an increase in SVI at least 10% following 4 ml kg-1 of Ringer's solution fluid challenge infused over 10 min.

MAIN OUTCOME MEASUREMENTS

Haemodynamic data, including SVI, were obtained from pulse contour analysis. The area under the receiver operating characteristic curves of the tests were compared with assess fluid responsiveness.

RESULTS

Fluid challenge administration induced an increase in SVI at least 10% in 51.5% of patients. The rate of fluid responsiveness was comparable among the three participant centres (P = 0.10). The area under the receiver operating characteristic curves (95% CI) of the changes in SVI after mini-FC was 0.95 (0.88 to 0.98), sensitivity 98.0% (89.5 to 99.6) and specificity 86.8% (75.1 to 93.4) for a cut-off value of 4% of increase in SVI. This was higher than the SVI changes after EEOT20, 0.67 (0.57 to 0.76) and after EEOT30, 0.73 (0.63 to 0.81).

CONCLUSION

In patients undergoing laparotomy the mini-FC reliably predicted fluid responsiveness with high-sensitivity and specificity. The EEOT showed poor discriminative value and cannot be recommended for assessment of fluid responsiveness in this surgical setting.

TRIAL REGISTRATION

NCT03808753.