ABSTRACT
BACKGROUND: Left ventricular (LV) diastolic function (DF) may play an important role in predicting fluid responsiveness. However, few studies assessed the role of diastolic function in predicting fluid responsiveness. The aim of this pilot study was to assess whether parameters of right and left diastolic function assessed with transesophageal echocardiography, including the mitral E/e' ratio, is associated with fluid responsiveness among patients undergoing elective bypass graft surgery. We also sought to compare other methods of fluid responsiveness assessment, including echocardiographic and hemodynamic parameters, pulse pressure variation, and stroke volume variation (SVV) (arterial pulse contour analysis, Flotrac/Vigileo system). RESULTS: We prospectively studied seventy patients undergoing coronary artery bypass grafting (CABG) monitored with a radial arterial catheter, transesophageal echocardiography (TEE), and a pulmonary artery catheter (for cardiac output measurements), before and after the administration of 500 mL of crystalloid over 10 min after the anesthetic induction. Thirteen patients were excluded (total of 57 patients). Fluid responsiveness was defined as an increase in cardiac index of ≥ 15%. There were 21 responders (36.8%) and 36 non-responders (63.2%). No difference in baseline pulsed wave Doppler echocardiographic measurements of any components of the mitral, tricuspid, and pulmonary and hepatic venous flows were found between responders and non-responders. There was no difference in MV tissue Doppler measurements between responders and non-responders, including E/e' ratio (8.7 ± 4.1 vs. 8.5 ± 2.8 in responders vs. non-responders, P = 0.85). SVV was the only independent variable to predict an increase in cardiac index by multivariate analysis (P = 0.0208, OR = 1.196, 95% CI (1.028-1.393)). CONCLUSIONS: In this pilot study, we found that no parameters of right and left ventricular diastolic function were associated with fluid responsiveness in patients undergoing CABG. SVV was the most useful parameter to predict fluid responsiveness. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02714244 . Registered 21 March 2016-retrospectively registered.
ABSTRACT
OBJECTIVES: The optimal temperature for blood cardioplegia remains unclear. METHODS: A retrospective analysis was performed on 138 patients undergoing isolated myocardial revascularization by a single surgeon in our institution over a period of 2 years. Patients operated on early in the study period received tepid (29°C) continuous minimally diluted blood cardioplegia (minicardioplegia), delivered in an antegrade continuous fashion. Later, our surgeon began using cold (7°C) blood minicardioplegia in all patients. Data pertaining to clinical outcomes and postoperative biochemical data were obtained, and the two groups were compared. RESULTS: Low cardiac output syndrome, defined as the need for intra-aortic balloon pump counter pulsation or inotropic medication for haemodynamic instability, was more frequent in the tepid cardioplegia group than in the cold cardioplegia group (16.0 vs 2.4%, P = 0.006). There was no difference in the maximal serum creatine kinase MB between the two groups (cold 25.4 ± 3.21 µg/ml vs tepid 36.5 ± 7.10 µg/ml, P = 0.62), in the rates of perioperative myocardial infarction (cold 1.2% vs tepid 6.0%, P = 0.15) and the need for postoperative insertion of an intra-aortic balloon pump (cold 4.8% vs tepid 0.0%, P = 0.3). There was no other statistically significant difference between the two groups in the measured parameters. CONCLUSIONS: A higher rate of low cardiac output syndrome in the tepid cardioplegia group suggests inferior myocardial protection with the tepid cardioplegia. Cold cardioplegia may provide better protection than tepid cardioplegia when minicardioplegia is used.
