Masui. The Japanese journal of anesthesiology
-
Case Reports
[Anesthesia for the intraoperative electrocorticography of patients with uncontrollable epilepsy].
For the surgical treatment of uncontrollable epilepsy, it is essential to delineate the epileptogenic focus by the use of intraoperative electrocorticography. Most general anesthetic agents, however, suppress the epileptogenic focus. Therefore, such a patient is usually kept awake during the procedure using local anesthesia. ⋯ In 2 patients, electrocorticographical focal seizure status was identified following the intraoperative electrocorticography. After the focus resection, seizure attacks were controlled only by the application of regular medical regimen in these patients. Low nitrous oxide and intermittent fentanyl administration can be recommended as a superior anesthesia technique for intraoperative electrocorticography.
-
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. ⋯ 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.
-
[The effects of fresh gas flow rate on the work of breathing during semi-closed circuit anesthesia].
To evaluate the effects of fresh gas flow rate on the work of breathing during semi-closed circuit anesthesia, we measured respiratory frequency, tidal volume, inspiratory work of breathing, peak inspiratory and expiratory flow rate and fluctuations in airway pressure during breathing with fresh gas flow of 6 l.min-1, 3 l.min-1 and 1.5 l.min-1. There was no significant difference among three flow rates in terms of tidal volume, respiratory frequency, inspiratory work of breathing, peak inspiratory flow rate and fluctuation in airway pressure at inspiration. On the other hand, in the expiratory phase, peak expiratory flow rate was lower and fluctuation in airway pressure at expiration was higher at 6 l.min-1 than those at 3 l.min-1 and 1.5 l.min-1, which may be indicative of increased expiratory work of breathing. The present study shows that low fresh gas flow rate does not increase the inspiratory work of breathing and high fresh gas flow rate may increase the expiratory work of breathing, implying that lowering the fresh gas flow is profitable for the work of breathing during semi-closed circuit anesthesia.
-
Comparative Study
[Differential effects of muscle relaxants on the evoked electromyogram of the thenar and hypothenar muscles].
This study compares the neuromuscular blocking effect of nondepolarizing relaxants on the thenar and hypothenar muscles in 14 anesthetized patients with nitrous oxide-halothane. Vecuronium (60 micrograms.kg-1 iv) or pancuronium (60 micrograms.kg-1 iv) was given and supramaximal stimulation was applied to ulnar nerve at the wrist. The evoked compound action potentials were measured over the thenar and hypothenar muscles of the right hand simultaneously. ⋯ There was significant higher T1/Tc and T1/T4 ratio for the hypothenar muscle than for the thenar muscle within 60 minutes from pancuronium administration. These data suggest that relative potency of muscle relaxant on these two muscles seems to be drug specific. This phenomenon brings certain practical difficulties on monitoring of neuromuscular function with evoked electromyogram during anesthesia.
-
We investigated the effects of arterial carbon dioxide tension on myocardial blood flow, tissue oxygen tension and metabolism in the anesthetized dogs. Eighteen adult mongrel dogs weighing 13.4 +/- 3.6 kg were anesthetized with 0.5% isoflurane, intubated and ventilated mechanically with 50% oxygen to maintain normocapnia. Endtidal CO2 fraction (FECO2) was monitored continuously by capnograph. ⋯ After normocapnic ventilation, hypocapnia was induced by increasing the respiratory rate, and hypercapnia was induced by adding 10% carbon dioxide to the inspired gas. The coronary blood flow and myocardial tissue oxygen tension increased during hypercapnia and the myocardial lactate extraction decreased, while excess lactate and cardiac venous L/P ratio increased during hypercapnia. These results indicate that hypercapnia increase coronary flow and myocardial tissue oxygen tension but myocardial aerobic metabolism is impaired during hypercapnia.