Slope analysis for the prediction of fluid responsiveness by a stepwise PEEP elevation recruitment maneuver in mechanically ventilated patients.

OBJECTIVE: Assessment of fluid responsiveness is problematic in intensive care unit patients. Lung recruitment maneuvers (LRM) can be used as a functional test to predict fluid responsiveness. We propose a new test to predict fluid responsiveness in mechanically ventilated patients by analyzing the variations in central venous pressure (CVP) and systemic arterial parameters during a prolonged sigh breath LRM without the use of a cardiac output measuring device. DESIGN: Prospective observational cohort study. SETTING: Intensive Care Unit, Saint-Etienne University Central Hospital. PATIENTS: Patients under mechanical ventilation, equipped with invasive arterial blood pressure, CVP, pulse contour analysis (PICCO™), requiring volume expansion, with no right ventricular dysfunction. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: CVP, systemic arterial parameters and stroke volume (SV) were recorded during prolonged LRM followed by a 500 mL fluid expansion to asses fluid responsiveness. 25 patients were screened and 18 patients analyzed. 9 patients were responders to volume expansion and 9 were not. Evaluation of hemodynamic parameters suggested the use of a linear regression model. Slopes for systolic arterial pressure, pulse pressure (PP), CVP and SV were all significantly different between responders and non-responders during the pressure increase phase of LRM (STEP-UP) (p = 0.022, p = 0.014, p = 0.006 and p = 0.038, respectively). PP and CVP slopes during STEP-UP were strongly predictive of fluid responsiveness with an AUC of 0.926 (95% CI, 0.78 to 1.00), sensitivity = 100%, specificity = 89% and an AUC = 0.901 (95% CI, 0.76 to 1.00), sensibility = 78%, specificity = 100%, respectively. Combining sensitivity of PP and specificity of CVP, prediction of fluid responsiveness can be achieved with 100% sensitivity and 100% specificity (AUC = 0.96; 95% CI, 0.90 to 1.00). One patient showed inconclusive values using the grey zone approach (5.5%). CONCLUSIONS: In patients under mechanical ventilation with no right heart dysfunction, the association of PP and CVP slope analysis during a prolonged sigh breath LRM seems to offer a very promising method for prediction of fluid responsiveness without the use and associated cost of a cardiac output measurement device. TRIAL REGISTRATION: NCT04304521 , IRBN902018/CHUSTE. Registered 11 March 2020, Fluid responsiveness predicted by a stepwise PEEP elevation recruitment maneuver in mechanically ventilated patients (STEP-PEEP).

Prevention of cardiac surgery-associated acute kidney injury by risk stratification using (TIMP-2)*(IGFBP7).

Aim: The purpose of this study was to assess urinary (TIMP-2)*(IGFBP7) for prevention of acute kidney injury (AKI) in patients undergoing elective cardiac surgery. Materials & methods: Two retrospective cohorts were analyzed before and after the implementation of urinary (TIMP-2)*(IGFBP7). The control cohort had a standard supportive care. For the (TIMP-2)*(IGFBP7) cohort, patients with the (TIMP-2)*(IGFBP7) >0.3 received renal supportive measures. Results: A total of 382 patients were included, 197 in the control cohort and 185 in intervention cohort. The incidence of AKI was significantly reduced in the (TIMP-2)*(IGFBP7) cohort (20.5 vs 29.9%, p < 0.05). In multivariate analysis, patients of the (TIMP-2)*(IGFBP7) cohort had a lower risk of developing AKI (p = 0.029). Conclusion: In conclusion, renal supporting care based on AKI risk stratification using urinary (TIMP-2)*(IGFBP7) may reduce AKI incidence.

Quality of Life After Cardiac Operations Based on the Minimal Clinically Important Difference Concept.

BACKGROUND: Health-related quality of life (HRQOL) is an increasingly important issue in assessing the consequences of any surgical or medical intervention. Our study aimed to evaluate change in HRQOL 6 months after elective cardiac operations and to identify specific predictors of poor HRQOL. METHODS: In this prospective, single-center study, HRQOL was evaluated before and 6 months after the operation using the Medical Outcome Study 36-Item Short Form Health Survey questionnaire and its two components: the Physical Component Summary and the Mental Component Summary. We distinguished patients with worsening of HRQOL according to the minimal clinically important difference. All consecutive adult patients undergoing cardiac operations were included. RESULTS: The preoperative and postoperative 36-Item Short Form Health Survey questionnaires were completed by 326 patients, and 24 patients died before completing follow-up questionnaires. On the basis of the definition used, clinically significant deterioration of HRQOL was observed in 93 patients (26.6%) for the Physical Component Summary and in 99 patients (28.2%) for the Mental Component Summary. Renal replacement for acute renal failure and mechanical ventilation for longer than 48 hours were independent risk factors for Physical Component Summary and Mental Component Summary worsening or death. CONCLUSIONS: Although our study showed overall improvement of quality of life after cardiac operations, more than one-quarter of the patients manifested deterioration of HRQOL at 6 months postoperatively. The findings from this study should help clinicians to inform patients about their likely postoperative functional status and quality of life.

High veno-arterial carbon dioxide gradient is not predictive of worst outcome after an elective cardiac surgery: a retrospective cohort study.

Alteration of tissue perfusion is a main contributor of organ dysfunction. In cardiac surgery, the importance of organ dysfunction is associated with worse outcome. Central venous-arterial difference in CO2 tension (ΔCO2) has been proposed as a global marker of the adequacy of tissue perfusion in shock states. We hypothesized that ΔCO2 could be increased in case of postoperative organ failure or worse outcome. In this monocentric retrospective cohort study, we retrieved, from our database, 220 consecutive patients admitted in intensive care after an elective cardiac surgery. Four time points were formed: ICU admission, and 6, 24 and 48 h after. A ΔCO2 below 6 mmHg defined the normal range values. The SOFA score, intensive care unit and hospital length of stay, hospital and 6-month mortality rate were recorded. We compared patient with low ΔCO2 (<6 mmHg) and high ΔCO2 (≥6 mmHg). We included 55 (25 %) and 165 patients in low and high ΔCO2 groups, respectively. The SOFA score, the hospital and 6 months mortality rate were higher in patients with low ΔCO2. Surprisingly, we did not find results previously published in other surgical settings. In cardiac surgery, ΔCO2 has a low predictive value of outcome.

Bedside assessment of passive leg raising effects on venous return.

OBJECTIVE: Passive leg raising (PLR) provides a reversible fluid-loading challenge and can be used to predict fluid responsiveness. The amount of blood volume recruited by this maneuver called stressed volume (Vs) is unknown. The present study aims to assess the quantitative effects of passive leg raising on venous return at bedside. METHODS: We conducted a prospective interventional study. Nine mechanically ventilated postoperative cardiac surgery patients with preserved left ventricular function were enrolled. Cardiac output (CO) was continuously monitored by PiCCO™ via the pulse contour method. Ten second intervals of inspiratory breath holding at four plateau pressures (5, 15, 25 and 35 cm H(2)O) were performed to measure the relationship between blood flow (CO) and central venous pressure (CVP). These were used to determine mean systemic filling pressure (Pmsf) and Vs. Patients were studied at three successive steps: semirecumbent position, after PLR and back in the semirecumbent position after volume expansion (VE). RESULTS: Similar to VE, PLR significantly increased Pmsf from 19.7 (17.0-22.6) mmHg at baseline to 22.0 (18.5-27.8) mmHg (p <0.05). CO increased 11.1% (9.5-20) with PLR and 14.8% (4.2-19.9) with VE. Venous return resistance was unchanged throughout the three conditions, whereas the the pressure gradient for venous return (Pmsf-CVP) increased during PLR (p = 0.058) and during VE (p < 0.05). Baseline circulatory compliance was 1.14 (0.52-2.65) ml mm Hg(-1) kg(-1). Vs increased to 3.5 (1.1-3.9) ml kg(-1) with PLR. CONCLUSIONS: The effect of transient hemodynamic changes on venous return induced by passive leg raising can be directly measured in intensive care patients using inspiratory-hold procedures. This technique makes quantification of PLR feasible and could be used clinically to assess fluid responsiveness.