Benoit Barrucand

High-Flow Nasal Oxygen vs Noninvasive Positive Airway Pressure in Hypoxemic Patients After Cardiothoracic Surgery: A Randomized Clinical Trial

IMPORTANCE Noninvasive ventilation delivered as bilevel positive airway pressure (BiPAP) is often used to avoid reintubation and improve outcomes of patients with hypoxemia after cardiothoracic surgery. High-flow nasal oxygen therapy is increasingly used to improve oxygenation because of its ease of implementation, tolerance, and clinical effectiveness. OBJECTIVE To determine whether high-flow nasal oxygen therapy was not inferior to BiPAP for preventing or resolving acute respiratory failure after cardiothoracic surgery. DESIGN AND SETTING Multicenter, randomized, noninferiority trial (BiPOP Study) conducted between June 15, 2011, and January 15, 2014, at 6 French intensive care units. PARTICIPANTS A total of 830 patients who had undergone cardiothoracic surgery, of which coronary artery bypass, valvular repair, and pulmonary thromboendarterectomy were the most common, were included when they developed acute respiratory failure (failure of a spontaneous breathing trial or successful breathing trial but failed extubation) or were deemed at risk for respiratory failure after extubation due to preexisting risk factors. INTERVENTIONS Patients were randomly assigned to receive high-flow nasal oxygen therapy delivered continuously through a nasal cannula (flow, 50 L/min; fraction of inspired oxygen [FiO2], 50%) (n = 414) or BiPAP delivered with a full-face mask for at least 4 hours per day (pressure support level, 8 cm H2O; positive end-expiratory pressure, 4 cm H2O; FiO2, 50%) (n = 416). MAIN OUTCOMES AND MEASURES The primary outcome was treatment failure, defined as reintubation, switch to the other study treatment, or premature treatment discontinuation (patient request or adverse effects, including gastric distention). Noninferiority of high-flow nasal oxygen therapy would be demonstrated if the lower boundary of the 95% CI were less than 9%. Secondary outcomes included mortality during intensive care unit stay, changes in respiratory variables, and respiratory complications. RESULTS High-flow nasal oxygen therapy was not inferior to BiPAP: the treatment failed in 87 of 414 patients with high-flow nasal oxygen therapy (21.0%) and 91 of 416 patients with BiPAP (21.9%) (absolute difference, 0.9%; 95% CI, -4.9% to 6.6%; P = .003). No significant differences were found for intensive care unit mortality (23 patients with BiPAP [5.5%] and 28 with high-flow nasal oxygen therapy [6.8%]; P = .66) (absolute difference, 1.2% [95% CI, -2.3% to 4.8%]. Skin breakdown was significantly more common with BiPAP after 24 hours (10% vs 3%; 95% CI, 7.3%-13.4% vs 1.8%-5.6%; P < .001). CONCLUSIONS AND RELEVANCE Among cardiothoracic surgery patients with or at risk for respiratory failure, the use of high-flow nasal oxygen therapy compared with intermittent BiPAP did not result in a worse rate of treatment failure. The findings support the use of high-flow nasal oxygen therapy in similar patients. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01458444.

Is Endocan a Diagnostic Marker for Pneumonia After Cardiac Surgery? The ENDOLUNG Study

BACKGROUND Postoperative pneumonia is frequent after cardiac surgery and is associated with increased morbidity and mortality. We tested the hypothesis that endocan is an early biomarker for the detection of pneumonia after cardiac surgery. METHODS Between January and May 2016, 155 patients scheduled to undergo elective cardiac surgery with cardiopulmonary bypass were prospectively included in the study. Serum level of endocan was measured at five timepoints (preoperative, and at 6, 24, 48, and 72 hours after the end of surgery). Procalcitonin and C-reactive protein were measured at 24 and 72 hours. The preoperative and postoperative characteristics of the patients were recorded. Independent predictors of postoperative pneumonia were identified by logistic regression. Threshold values of endocan predictive of postoperative pneumonia were determined using receiver-operating characteristics curve analysis. RESULTS Seventeen patients (11%) had pneumonia after surgery. Endocan greater than 3.7 ng/mL before induction of anesthesia, or greater than 12.1 ng/mL at 6 hours after surgery, as well body mass index higher than 27 kg/m2 and duration of surgery were independent predictors of postoperative pneumonia. At induction of anesthesia, an endocan cutoff value of 3.7 ng/mL had 65% sensitivity and 72% specificity for the prediction of postoperative pneumonia; whereas at 6 hours, with a cutoff value of 12.1 ng/mL, these values were 71% and 75%, respectively. The time saved by endocan dosage compared with clinical diagnosis of postoperative pneumonia was 96 hours. CONCLUSIONS This study shows that endocan is an early marker of postoperative pneumonia in patients after cardiac surgery.

Relevance of Endothelial Cell-Specific Molecule 1 (Endocan) Plasma Levels for Predicting Pulmonary Infection after Cardiac Surgery in Chronic Kidney Disease Patients: The Endolung Pilot Study

Objectives: This pilot study aimed to evaluate the relevance of endocan plasma levels for predicting pulmonary infection after cardiac surgery in patients with chronic kidney disease (CKD). Methods: Serum collected in a previous prospective cohort study (from 166 patients with preoperative CKD who underwent cardiac surgery) was used. Five patients with postoperative pulmonary infection were compared with 15 randomly selected CKD patients with an uneventful outcome. Blood samples were tested at 4 time points (preoperatively and 6, 12, and 24 h after the end of surgery). Endocan, procalcitonin, and C-reactive protein plasma levels were compared between the two groups. Results: At 6 h, the patients with pulmonary infection had significantly higher levels of endocan than the patients without pulmonary infection (24.2 ± 15.6 vs. 6.4 ± 3.2 ng/mL; p = 0.03). A receiver operating characteristic curve analysis showed 80% sensitivity and 100% specificity for endocan to predict pulmonary infection (area under the curve 0.84), with a cutoff value of 15.9 ng/mL. The time saved by assessment of the endocan dosage compared to a clinical diagnosis of pulmonary infection was 47 h. Conclusion: This pilot study showed that a specific study to assess the link between endocan plasma levels and pulmonary infection after cardiac surgery in CKD patients is of potential utility.

Kinetics of endocan in patients undergoing cardiac surgery with and without cardiopulmonary bypass

HighlightsEndocan plays a major role in inflammation and infection.We describe kinetics of endocan in cardiac surgery with and without CPB.Kinetics of endocan release differs according to whether surgery is on‐ or off‐pump.In patients with CPB, endocan peaks and is significantly higher at 6 h after surgery.In off‐pump surgery, endocan peaks at 24 h after surgery, then declines gradually. Background: Endocan plays an important role in the processes of inflammation and infection. The use of cardiopulmonary bypass (CPB) during cardiac surgery can induce an inflammatory response. We aimed to describe the kinetics of endocan in patients undergoing cardiac surgery with and without the use of CPB. Methods: Single‐centre, observational study with retrospective analysis of prospectively collected data, to compare the kinetics of endocan in patients undergoing isolated coronary artery bypass graft (CABG) surgery. Endocan was measured at induction of general anesthesia (baseline), and at 6, 24, 48 and 72 h after the end of surgery. Patients were classified into two groups, namely those undergoing CPB (CPB group) and those without CPB (off‐pump group). Results: In total, 91 patients were included in this analysis: 61 patients in the CPB group and 30 in the off‐pump group. There were no major significant differences between groups. Patients with CPB had a significantly higher level of endocan at 6 h (9.7 ± 6.7 ng/ml vs 6.9 ± 3.3 ng/ml, p = 0.03), but the difference was no longer statistically significant at subsequent timepoints. Endocan values were not significantly correlated with the duration of CPB (p = 0.53). Conclusion: Endocan levels in patients undergoing isolated CABG surgery with CPB are significantly higher at 6 h than in patients with off‐pump surgery, and peaks earlier in those with CPB (6 h) than in those undergoing off‐pump surgery (24 h).

Clinical Effectiveness of Intravenous Exenatide Infusion in Perioperative Glycemic Control after Coronary Artery Bypass Graft Surgery: A Phase II/III Randomized Trial

Background: We aimed to assess the clinical effectiveness of intravenous exenatide compared to insulin in perioperative blood glucose control in coronary artery bypass grafting surgery patients. Methods: Patients more than 18 yr old admitted for elective coronary artery bypass grafting were included in a phase II/III nonblinded randomized superiority trial. Current insulin use and creatinine clearance of less than 60 ml/min were exclusion criteria. Two groups were compared: the exenatide group, receiving exenatide (1-h bolus of 0.05 µg/min followed by a constant infusion of 0.025 µg/min), and the control group, receiving insulin therapy. The blood glucose target range was 100 to 139 mg/dl. The primary outcome was the proportion of patients who spent at least 50% of the study period within the target range. The consumption of insulin (Cinsulin) and the time to start insulin (Tinsulin) were compared between the two groups. Results: In total, 53 and 51 patients were included and analyzed in the exenatide and control groups, respectively (age: 70 ± 9 vs. 68 ± 11 yr; diabetes mellitus: 12 [23%] vs. 10 [20%]). The primary outcome was observed in 38 (72%) patients in the exenatide group and in 41 (80%) patients in the control group (odds ratio [95% CI] = 0.85 [0.34 to 2.11]; P = 0.30). Cinsulin was significantly lower (60 [40 to 80] vs. 92 [63 to 121] U, P < 0.001), and Tinsulin was significantly longer (12 [7 to 16] vs. 7 [5 to 10] h, P = 0.02) in the exenatide group. Conclusions: Exenatide alone at the dose used was not enough to achieve adequate blood glucose control in coronary artery bypass grafting patients, but it reduces overall consumption of insulin and increases the time to initiation of insulin.

Acute Kidney Injury After Cardiac Surgery

Cardiac surgery remains one of the most common high-risk surgeries in the world. Acute kidney injury (AKI) is one of the most frequent and serious complications to occur following cardiac surgery, with an incidence ranging from 5 to 40% depending on specific definition of AKI, the preoperative renal status of the patient, and the type of surgery. Although postoperative AKI requiring dialysis is rare, it is independently associated with mortality, and the risk of mortality is high in these patients, averaging around 60–70%. The pathogenesis of AKI in cardiac surgery is complex and multifactorial, and results from mechanisms that can cause injury during the preoperative, intraoperative, and postoperative phases. Risk factors for AKI include preoperative (patient-related) risk factors (e.g., female gender, reduced left ventricular ejection fraction, congestive heart failure, advanced age, diabetes) and perioperative (procedure-related) factors (e.g., off-pump vs on-pump surgery, duration of cardiopulmonary bypass, hypothermia, volume status, anemia, hemodilution). The diagnosis of cardiac surgery associated AKI relies mainly on biomarkers, and serum creatinine remains the most important biomarker routinely used since no suitable substitute that is equally as feasible and inexpensive has been identified to date. However, the detective ability of serum creatinine is low, and its response to renal insult is slow and late. We discuss here new biomarkers for the detection of post-cardiac surgery AKI, including cystatin C, interleukin (IL)-18, L-type fatty acid-binding protein, and neutrophil gelatinase-associated lipocalin. We discuss options for pharmacological renal protection to prevent post-cardiac surgery AKI.