Transesophageal tissue Doppler echocardiography for evaluation of myocardial function during aortic valve replacement.

OBJECTIVE: Tissue Doppler imaging is an evolving ultrasound technology that, compared with traditional echocardiography, promises reduced subjectivity in the assessment of myocardial performance and contributes new information on myocardial function. The aim of this study was to evaluate the feasibility of transesophageal tissue Doppler imaging in the setting of aortic valve replacement. DESIGN: Feasibility study. SETTING: Aarhus University Hospital, Denmark. PARTICIPANTS: Twelve patients with isolated aortic valve stenosis or combined ischemic cardiomyopathy and aortic valve stenosis scheduled for elective aortic valve replacement were included. INTERVENTION: Transgastric short-axis recordings of the left ventricular anterior wall were performed using Vivid-7 technology (GE Healthcare, Horten, Norway) with activated tissue Doppler imaging before sternotomy, at intervals during progressive withdrawal of cardiopulmonary bypass, and within 1 hour after transfer to the postoperative care unit. Data were postprocessed for assessment of systolic radial function with the tissue Doppler modalities, tissue velocity, end-systolic strain rate, and strain by using dedicated software. RESULTS: Accurate tissue Doppler data were obtained for all patients at baseline and postoperatively. During the gradual loading of the left ventricle, velocity measurements were all obtained accurately, whereas 8% to 25 % of strain and strain-rate measurements were considered unreliable. Immediately after cardioplegia, 33% to 58% of measurements were unreliable. CONCLUSIONS: Transesophageal tissue Doppler is feasible in the intraoperative setting, although unreliable data acquisition occurs during cardiopulmonary bypass. Tissue Doppler is a promising quantitative tool for monitoring of myocardial function within minutes and may also reveal new information on myocardial function in patients undergoing thoracic surgery.

Reversal of rocuronium-induced neuromuscular block by the selective relaxant binding agent sugammadex: a dose-finding and safety study.

BACKGROUND: Sugammadex (Org 25969) forms a complex with steroidal neuromuscular blocking agents, thereby reversing neuromuscular block. This study investigated the dose-response relation, safety, and pharmacokinetics of sugammadex to reverse rocuronium-induced block. METHODS: Twenty-seven male surgical patients aged 18-64 yr were randomly assigned to receive placebo or sugammadex (0.5, 1.0, 2.0, 3.0, or 4.0 mg/kg) for reversal of 0.6 mg/kg rocuronium-induced neuromuscular block. Anesthesia was induced and maintained using intravenous fentanyl and propofol. Neuromuscular function was assessed using acceleromyography. Sugammadex or placebo was administered at reappearance of T2 of the train-of-four. The primary efficacy variable was the time required for recovery to a train-of-four ratio of 0.9. RESULTS: Sugammadex decreased median recovery time in a dose-dependent manner from 21.0 min in the placebo group to 1.1 min in the group receiving 4.0 mg/kg sugammadex. Doses of sugammadex of 2.0 mg/kg or greater reversed rocuronium-induced neuromuscular block within 3 min. A median of 59-77% of sugammadex was excreted unchanged in the urine within 16 h, mostly in the first 8 h. Sugammadex increased the proportion of the rocuronium dose excreted unchanged in the urine (from a median of 19% in the placebo group to 53% in the 4.0-mg/kg group within 16 h). Sugammadex was safe and well tolerated. No evidence of recurarization was observed in any patient. CONCLUSION: At doses of 2.0 mg/kg or greater, sugammadex safely reversed 0.6 mg/kg rocuronium-induced neuromuscular block in a dose-dependent manner. Sugammadex enhanced renal excretion of rocuronium and was excreted unchanged by the kidneys.