The Mechanism of Mitral Regurgitant Jets Identified by 3-Dimensional Transesophageal Echocardiography.

This study is a case report, which presents a case of severe mitral regurgitation in a 77-year-old man. Two-dimensional transesophageal echocardiography (TEE), regurgitant jets directed anteriorly in early systole and centrally to laterally in late systole were seen, while three-dimensional TEE showed a flail posterior middle scallop not only angulated centrally, but also laterally, which provided insight into the mechanism of mitral regurgitant jet direction. This case demonstrates the clinical usefulness of 3-dimensional TEE for identifying the mechanism of mitral regurgitant jets. The institution where the figures and the videos were recorded: Division of Cardiology, Mazankowski Alberta Heart Institute, University of Alberta Hospital, Edmonton, Alberta, Canada.

Effects of cardiac output on the onset of rocuronium-induced neuromuscular block in elderly patients.

PURPOSE: The aim of this study was to elucidate the relationship between the onset of rocuronium-induced neuromuscular block and arterial pressure-based cardiac output (CO) in elderly patients. METHODS: Forty elderly patients aged 65-83 years were enrolled in this study. After induction of anesthesia, contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation were acceleromyographically evaluated and 1 mg/kg rocuronium was administered following CO measurement. The correlation between onset of rocuronium action and CO was analyzed. RESULTS: The mean [SD] CO reduced after induction of anesthesia from 5.1 [1.8] L/min to 3.8 [1.1] L/min. The onset time of rocuronium-induced neuromuscular block was 110.3 [23.9] s (range 60-165). There was a statistically significant inverse correlation between the onset time of rocuronium and CO [onset time (s) = - 13.2·CO + 159.7, R2 = 0.376]. CONCLUSIONS: In the elderly, CO influences the onset of action of rocuronium.

Effectiveness of the timing principle with high-dose rocuronium during rapid sequence induction with lidocaine, remifentanil and propofol.

PURPOSE: The main purpose of this study was to examine the effectiveness of the timing principle with 1 mg kg(-1) rocuronium for rapid sequence intubation. As secondary outcomes, propofol and lidocaine with or without remifentanil were examined to note their effects on the cardiovascular responses to laryngoscopy and intubation. METHODS: Thirty patients were randomly allocated to one of two groups of 15 patients each: a lidocaine-treated group (L) and a lidocaine/remifentanil-treated group (LR). Thirty seconds after lidocaine 1 mg kg(-1) with or without infusion of remifentanil 1 microg kg(-1) min(-1), all patients received a bolus of rocuronium 1 mg kg(-1). Shortly afterwards, patients were given propofol 2-2.5 mg kg(-1). Intubating conditions and cardiovascular responses were observed 60 s after rocuronium. The time to spontaneous recovery of visible train-of-four (TOF) counts of 4 was observed at the thumb during 1.0-1.5% end-tidal sevoflurane and remifentanil anesthesia. RESULTS: All patients had excellent or good intubating conditions. Hypertension and tachycardia during laryngoscopy were well prevented in group LR, whereas they were significantly observed in group L. The times to reappearance of TOF counts of 4 were comparable in all groups [mean (SD); 63.6 (8.6) min in group L and 63.5 (11.6) min in group LR]. CONCLUSION: Application of the timing principle with 1 mg kg(-1) rocuronium is beneficial for rapid tracheal intubation. Co-administered lidocaine, remifentanil and propofol can definitely suppress cardiovascular responses during laryngoscopy and intubation.

Effect of landiolol hydrochloride on suxamethonium-induced neuromuscular block.

PURPOSE: The aim of this study was to examine the effect of landiolol hydrochloride, an ultrashort-acting beta(1)-blocker, on suxamethonium-induced neuromuscular block. METHODS: Thirty patients were randomly allocated to receive a loading dose of landiolol, 0.125 mg x kg(-1) x min(-1) for 1 min, followed by an infusion at 0.04 mg x kg(-1) x min(-1), or placebo. Twenty minutes after the infusion of landiolol or placebo, suxamethonium 1 mg x kg(-1) was administered during propofolfentanyl-nitrous oxide anesthesia. Neuromuscular block was monitored by train-of-four (TOF) responses of the adductor pollicis muscle, applying acceleromyographic stimuli to the ulnar nerve. RESULTS: The onset of neuromuscular block did not differ between the groups. The time from administration of suxamethonium to spontaneous recovery to the first twitch of TOF (T1) of control was significantly longer in the landiolol group (mean [SD]; 12.2 [2.5] min), when compared with the control group (9.8 [2.6] min). However, the TOF ratios measured when the T1 had spontaneously recovered to 10%, 25%, 50%, 75%, 90%, and 100% of control was comparable between the groups. CONCLUSION: Landiolol delayed recovery from suxamethonium-induced paralysis. However, the interaction between the drugs seemed to be small in the clinical setting.