Alain Brusset

Comparison of monitoring performance of Bioreactance vs. pulse contour during lung recruitment maneuvers.

IntroductionThis study was designed to test the hypothesis of equivalence in cardiac output (CO) and stroke volume (SV) monitoring capabilities of two devices: non invasive transthoracic bioreactance (NICOM), and a pulse contour analysis (PICCO PC) coupled to transpulmonary thermodilution (PICCO TD).MethodsWe included consecutive patients of a single ICU following cardiac surgery. Continuous minute-by-minute hemodynamic variables obtained from NICOM and PICCO PC were recorded and compared in 20 patients at baseline, during a lung recruitment maneuver (20 cmH2O of PEEP) and following withdrawal of PEEP. PICCO TD measurements were also determined. We evaluated the accuracy of these two technologies at baseline using PICCO TD as reference and we estimated the precision by the fluctuation around the mean value (2SD/mean). Then, we assessed time response, amplitude response and reliability for detecting expected decreases when PEEP was applied. Type I and type II errors were analyzed.ResultsCO values (PICCO TD) ranged from 1.6 to 8.0 L.min-1. At baseline, CO values were comparable for NICOM, PICCO PC and PICCO TD: 5.0 ± 1.2, 4.7 ± 1.4 and 4.6 ± 1.3 L.min.-1, respectively (NS). Limits of agreements with PICCO TD were 1.52 L.min.-1 for NICOM and 1.77 L.min.-1 for PICCO PC, NS. The 95% statistical power gives an equivalence with a threshold of 0.52 L.min.-1 for NICOM vs. PICCO PC. The CO precision was 6 ± 3% and 6 ± 5% for NICOM and PICCO PC, respectively, NS. When PEEP was applied, CO was reduced by 33 ± 12%, 31 ± 14% and 32 ± 13%, for NICOM, PICCO PC and PICCO TD, respectively (NS). Time response was 3.2 ± 0.7 minute for NICOM vs. 2 ± 0.5 minute for PICCO PC (NS). SV results were comparable to those for CO.ConclusionsAlthough limited to 20 patients, this study has enough power to show comparable CO and SV monitoring capabilities of Bioreactance and pulse contour analysis calibrated by transpulmonary thermodilution.

Assessment of systematic use of intraoperative transesophageal echocardiography during cardiac surgery in adults: A prospective study of 203 patients

OBJECTIVE To determine the usefulness of systematic intraoperative transesophageal echocardiography in a cardiac surgical unit. DESIGN Open prospective observational survey. SETTING University Hospital. PARTICIPANTS Consecutive adult patients (n = 203) undergoing elective or urgent cardiac operations. MEASUREMENTS AND MAIN RESULTS Pre-cardiopulmonary bypass imaging yielded unsuspected findings in 26 patients (12.8%) and changed the planned surgery in 22 patients (10.8%). Transesophageal echocardiography modified the diagnosis in eight patients (17%) operated on for mitral valvulopathy, in seven patients (15.5%) with aortic valvular disease, in four patients (4.6%) with coronary artery disease, in five patients operated on for thoracic aorta diseases regardless of their localization (18.5%), and in two miscellaneous cases. On the basis of the data obtained from the transesophageal echocardiography carried out at the end of cardiopulmonary bypass, an immediate reintervention was required in five cases (2.5%). CONCLUSIONS It is concluded that systematic intraoperative transesophageal echocardiography significantly affected decision making in this cardiac surgical unit. Its routine use in all cardiac surgical patients is recommended.

High-dose alfentanil for myocardial revascularization: A hemodynamic and pharmacokinetic study

It has been suggested that high plasma levels of alfentanil are required in order to control hemodynamic responses to noxious stimuli in patients undergoing myocardial revascularization. The present study was designed to determine the hemodynamic profile in 10 patients and the time course of alfentanil plasma concentrations and pharmacokinetics (7 patients) during and following coronary artery surgery using alfentanil administration based on an overdosage principle. Premedication consisted of lorazepam, 0.07 mg/kg, given 2 hours before surgery. Ten milligrams of alfentanil was given over 5 minutes for anesthesia induction, followed by an infusion of 60 mg/h until sternotomy and 30 mg/h up to skin closure. Additional 5-mg boluses were given prior to noxious intraoperative events. Hemodynamic measurements were performed prior to cardiopulmonary bypass. Blood was sampled simultaneously prebypass and then during the postbypass period for determination of alfentanil plasma levels. The very high alfentanil plasma concentrations achieved provided satisfactory intraoperative conditions in most, but not all, patients. Recovery time was short, despite the large amounts of narcotic used. It is concluded that very high doses of alfentanil associated with lorazepam premedication resulted in hemodynamic stability and markedly elevated narcotic plasma concentrations in most patients. Such plasma levels seem to provide satisfactory anesthetic conditions.

Heart failure with preserved ejection fraction as an independent risk factor of mortality after cardiothoracic surgery

Background: The prognostic role of heart failure with preserved ejection fraction (HFpEF) remains unclear. This study aimed to assess HFpEF prognostic value after cardiothoracic surgery, adjusting for European System for Cardiac Operative Risk (EuroSCORE II) criteria. Methods: Patients with left ventricular ejection fraction (LVEF) ≥ 50% undergoing cardiothoracic surgery between 2012 and 2016 were included. Patients with HFpEF were compared to control patients with LVEF ≥ 50%. HFpEF was defined following 2016 European Society of Cardiology guidelines: LVEF ≥ 50%, symptomatic HF with New York Heart Association (NYHA) class 2 or greater, elevated brain natriuretic peptide (BNP) and relevant echocardiographic findings (LV hypertrophy, LA enlargement, or diastolic filling anomaly). The primary endpoint was in‐hospital mortality, and the secondary endpoint was postoperative shock. Multivariate analyses were performed to determine mortality and shock risk‐factors. Results: Among 1743 patients, 427 (24.5%) presented HFpEF. HFpEF was highly associated with in‐hospital mortality (hazard ratio = 1.86; 95% confidence interval [CI], 1.16‐2.98; P = .01). This association remained independent when adjusting for EuroSCORE II (adjusted hazard ratio = 1.6; 95% CI, 1.0‐2.6; P = .049). Postoperative shock occurred more in HFpEF than in control patients (17.8% vs 6.7%; P < .001). HFpEF was an independent risk factor of postoperative shock (adjusted odds ratio = 2.9; 95% CI, 1.5‐3.0; P < .001). Conclusions: HFpEF was an independent risk‐factor of mortality and postoperative shock after cardiothoracic surgery, after adjustment regarding EuroSCORE II.

Frequency of Recovery from Complete Atrioventricular Block After Cardiac Surgery

Best timing for permanent pacemaker implantation to treat complete atrioventricular block (AVB) after cardiac surgery is unclear, as late pacemaker dependency was found low in recent observational studies. This study aimed to identify factors associated with spontaneous recovery from AVB. In a prospective and observational cohort, all patients who underwent cardiothoracic surgery during a 14-month-period were included (n = 1,200). Risk factors of postoperative AVB were assessed by logistic regression. Among patients who developed AVB, variables associated with recovery from AVB were assessed by Cox and logistic regression. Overall incidence of postoperative AVB was 6.0%. Risk factors of AVB were age (OR 1.03 [1.00 to 1.06], p = 0.023); female gender (OR 2.06 [1.24 to 3.41], p = 0.005), active endocarditis (OR 3.31 [1.33 to 8.26], p = 0.01), and aortic valve replacement (OR 3.17 [1.92 to 5.25], p <0.001). Among aortic valve replacement, sutureless aortic valve replacement was associated with more AVB (26.7% vs 8.1%, p <0.01). Recovery from AVB occurred in 30 patients (41.7%) in a median period of 3 days [interquartile range = 1;5]. Among patients who would recover from AVB, 90% of patients did so before day 7. None of the studied variable was independently associated with recovery from AVB. In conclusion, identified risk factors of postoperative AVB after cardiac surgery were age, female gender, endocarditis, and aortic valve replacement. Because most patients who would recover did so before day 7, this study validates modern guidelines suggesting permanent pacemaker implantation on day 7.