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H Tobata

Publications and source records attributed to H Tobata.

5 recordsLinked to original sources
PubMed1994

Double burst stimulation with submaximal current.

The present study evaluated responses to double burst stimulation (DBS) at supramaximal and submaximal currents in 30 adult patients. Usually, DBS is applied with supramaximal stimulation, but this may be quite uncomfortable for the awake patient. Therefore, the authors investigated whether it is possible to obtain an accurate assessment of significant residual neuromuscular blockade if the stimulus current is reduced to 30 mA. In all patients, neuromuscular response to DBS three three (DBS3.3), DBS three two (DBS3.2) and train-of-four (TOF) stimulation at supramaximal and/or submaximal currents was recorded using a mechanomyograph, and the ratios of the fourth to the first twitch (T4/T1) induced by TOF stimulation at supramaximal current, and the height of the second response to the first (D2/D1) induced by DBS at 30 mA and supramaximal current were calculated. The relations between control T4/T1 ratios determined by supramaximal TOF stimulation and D2/D1 ratios determined by supramaximal DBS3.3 and submaximal DBS3.3 were Y = 0.99X + 0.08 and Y = 1.01X + 0.04, respectively, and there was no statistical difference between the two regression lines. The same relation between T4/T1 ratios and D2/D1 ratios by DBS3.2 were Y = 0.69X + 0.05 and Y = 0.72X + 0.02, respectively, and there was no significant difference. It is concluded that evaluation of the response to DBS at 30 mA has the same reliability as evaluation with supramaximal current.

Adult↗
PubMed1994

[A new neuromuscular transmission monitor (TOF Guard): the rationale behind the method and its clinical usefulness].

TOF Guard is one of the latest developments in the field of neuromuscular monitoring equipment. This system uses a miniature acceleration transducer (a piezo-electric ceramic wafer is used), simply fastened to the thumb with tape. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. In this study, authors assessed the accuracy of this system in clinical use, comparing with the force transducer method (Myograph 2000). The result showed that there was a very close positive correlation between the values of T1, TOF ratio and posttetanic count simultaneously measured by both methods. The coefficient of correlation was 0.96, and its significance level was P < 0.001. From the clinical view point, it is concluded that TOF Guard is very useful because of its accuracy and because the equipment is easy to handle, compact and of low price as a neuromuscular monitoring system for routine anesthesia.

Adult↗
PubMed1993

Determining the optimal time for endotracheal intubation during onset of neuromuscular blockade.

The disappearance of the response to single twitch stimulation (STS), double burst stimulation (DBS) and zero post-tetanic count (PTC) were evaluated to determine which best indicated the optimal time of endotracheal intubation during onset of neuromuscular blockade induced by vecuronium (0.08 mg kg-1) in 199 patients under thiopentone and halothane anaesthesia. Evaluations were performed by mechanomyographic and manual methods using a Myograph and a peripheral nerve stimulator. The study consisted of six parts. In part 1 (n = 30) and part 2 (n = 30), the response to STS (0.1 Hz) were evaluated mechanically and manually, respectively. In part 3 (n = 64), post-tetanic count (PTC) changes were evaluated mechanically. In part 4 (n = 30) and part 5 (n = 30), response to DBS were evaluated mechanically and manually, respectively. Intubation was performed immediately after obtaining zero PTC, or absence of response to STS (0.1 Hz) and DBS, and the intubation score was determined. In the control group of patients, intubation was performed under the same anaesthetic conditions as in parts 1-5 but without the administration of any muscle relaxant. The time from administration of any muscle relaxant. The time from administration of vecuronium until disappearance of response was 2.16 +/- 0.56, 2.49 +/- 0.68, 2.04 +/- 0.29, 2.20 +/- 0.53, and 2.97 +/- 0.61 min in parts 1-5, respectively. Excellent intubation conditions were not established in any of the control patients, and in 50.0, 70.0, 55.0, 70.0 and 90.0% of the patients in parts 1-5, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

QRS complex changes in the V5 ECG lead during cardiac surgery.

The QRS complex in lead V5 was studied during cardiac surgery. R wave amplitude decreased after induction of anesthesia to approximately 50% to 60% of the preanesthetic level before the institution of CPB (P < 0.001). An rS complex appeared immediately after cardioversion and changed in configuration to an Rs complex 15 to 30 minutes after aortic declamping. The R wave continued to recover toward the preanesthetic level at sternal closure. Patients with coronary artery disease had a poorer recovery of the R wave (P < 0.05) than patients with valvular heart disease; the former recovered to only 50% of the preanesthetic level at sternal closure. Nonsurvivors had much smaller R waves (26.1 +/- 20.5%) than survivors (P < 0.001). The R wave peaked 30 to 40 ms after initiation of the QRS complex, which indicates recovery of conductivity and the activation sequence of the left ventricular (LV) free wall, which is easily disturbed by hypothermia, cardioplegia, and ischemia during aortic cross-clamping. Monitoring QRS complex changes in lead V5 appears to be important on weaning from cardiopulmonary bypass to detect regional ischemia, and also to observe electrophysiologic recovery of the LV free wall.

Adult↗