Search

To evaluate the influence of succinylcholine (Scc) on the neuromuscular blocking effect of subsequently administered vecuronium in children, 30 patients aged 2-14 years scheduled for elective surgery were studied after obtaining the informed consent from the parents. Anesthesia was induced with inhalation of sevoflurane, nitrous oxide and oxygen. T1 of the adductor pollicis muscle to ulnar nerve stimulation elicited by train of four stimulation at 2 Hz was monitored continuously by an acceleration transducer. The patients were divided into two groups; group V (16 patients) received vecuronium (0.03 mg.kg-1) and group SV (14 patients) received vecuronium (0.03 mg.kg-1) after 100% recovery of twitch from neuromuscular blockade induced with Scc (1.0 mg.kg-1). Short onset of action and potentiation of maximal block were demonstrated in group SV. After vecuronium administration, a complete suppression of T1 was observed in 8 patients of group SV and only 1 patient of group V. The present study demonstrates that the neuromuscular blockade of vecuronium can be potentiated with the prior administration of Scc in pediatric patients.

Sodium bicarbonate has been added to various local anesthetics for shortening the onset time. We often noticed the precipitate in the pH-adjusted local anesthetics several minutes after adding the bicarbonate. We confirmed that this drug interaction was caused by large changes in pH. We have analyzed the precipitates by mass spectrometry and infrared absorption spectrum and have revealed it as unionized base forms of local anesthetics. Since these forms tend to be insoluble, we must limit the amount of 7% sodium bicarbonate. This study proposes a guideline for adding 7% sodium bicarbonate to the various local anesthetics. The amount of 7% sodium bicarbonate which can be added to bupivacaine without precipitation is below 0.02 ml. In cases of mepivacaine and lidocaine, allowable amount of 7% sodium bicarbonate is 0.5 ml. It is not known whether this lower dose of 7% sodium bicarbonate compared with the recent reports is effective or not. Further clinical investigation may be necessary.

A patient with mild hypothyroidism underwent a repair of abdominal aortic aneurysm. Although the serum TSH level of this patient was very high and T4, free T4 levels were low, T3 level remained within normal ranges. Inhalation anesthesia with continuous epidural block was selected and there was no complication such as hypotension or hypothermia during perioperative period. Recently, several reports demonstrate that the preoperative supplemental therapy of the thyroid hormone should not be necessary in the case of mild hypothyroidism. Moreover, the biological potency of T3 is higher than that of T4. Thus, in patients whose T3 level is kept within normal ranges even if serum T4 level is low and serum TSH level is high, we may say that they are in euthyroid state. We think these patients can be anesthetized safely.

Excessively high concentration of halothane vapor was delivered to the inspiratory gas mixture due to the vaporizer malfunction (Fluotec 4). After disassembling the vaporizer, corrosion was observed on the internal components. This was considered as the reason for the high halothane output. Proper regular check up, use of appropriate monitoring devices, and a preuse equipment checklist may help improve the quality of patient care and decrease the morbidity and mortality associated with anesthesia equipment. Anesthesia machines should receive regular check up at least once a year and anesthesia providers should routinely use an equipment checklist. It is also important to realize that anesthesiologist's senses of sight, hearing, touch, and smell are exceedingly reliable monitors for decreasing the incidence of anesthesia mishaps.

A 46 year old male patient was admitted with fever and cough. A chest X-ray film revealed a foreign body shadow of a denture fragment in the right intermediate bronchus that he had swallowed one year and half ago. Rigid bronchoscopy was used to remove the foreign body under general anesthesia. During the procedure, massive hemorrhage occurred from bronchus, and the foreign body was not removed successfully and the patient sustained near cardiac arrest. Postoperatively, he recovered from the near fatal condition with support of mechanical ventilation in ICU for several days. After one month, pulmonary angiography was performed and it revealed the transfiguration of pulmonary artery and other vessels close to the foreign body. Granular tissue around the foreign body was observed by preoperative bronchoscopy. Disruption of such vessels and granular tissue by rigid and forced fiberscopy was suspected to have caused the massive bleeding. Later, the denture fragment was successfully removed by right thoracotomy. We should take this complication into consideration and preoperative fiberoptic bronchoscopy and pulmonary angiography may be beneficial to the anesthetic management of such patients.

The influence of prostaglandin E1 (PGE1) on PaO2 at doses that produced slight hypotension was evaluated in 176 patients scheduled for surgery. When systolic blood pressure was stabilized after induction of anesthesia, PGE1 infusion was started until 20% reduction of systolic blood pressure was achieved. Arterial blood gases were analyzed before infusion of PGE1 and 30 min after the completion of this hypotensive level respectively. The reductions in both PaO2 [from 177 +/- 64 mmHg to 164 +/- 65 mmHg (mean +/- SD) (P < 0.01)] and PaO2/FIO2 [from 486.5 +/- 144.4 to 437.6 +/- 121.6 (P < 0.01)] were observed with PGE1 infusion of 0.079 +/- 0.068 micrograms.kg-1.min-1. The results of this study show that PaO2 decreases during induced hypotension with PGE1 infusion, but this decrease is not clinically significant.

The relation between the patient's consciousness level and the change in electroencephalographic (EEG) activity during general anesthesia has not been well understood. In the present study, we evaluated such relationship quantitatively during the induction of high-dose fentanyl anesthesia in adult open-heart cases. There are significant increase in delta activity and significant decrease in alpha and beta activity in response to the induction of anesthesia. The loss of consciousness coincided with the sharp reduction in delta ratio and edge frequency (80%). Such reduction was more prominent in delta ratio than in edge frequency. These findings suggest that delta ratio could indicate the consciousness level during the induction of high-dose fentanyl anesthesia. Further study is needed to clarify the EEG response during inhalation and intravenous anesthesia in relation to EEG activity.

The present study was performed to evaluate postoperative hoarseness quantitatively by means of acoustic wave form analysis. Pitch and amplitude perturbation (PPQ, and APQ), and normalized noise energy (NNE) were measured along with the frequency characteristics in 51 adult patients undergoing elective surgery. The normal values for these acoustic parameters were less than 0.5%, less than 2.0%, and less than -10 dB, respectively. Vowel sound "E" was recorded and evaluated before the induction of anesthesia and on the morning of the day after the surgery. PPQ increased from 0.39% to 1.00% (P less than 0.05), APQ increased from 3.34% to 6.62% (P less than 0.05), and NNE increased from -9.19 dB to -4.74 dB (P less than 0.05). Eighteen percent of the patients showed abnormal values in all parameters preoperatively, but 45% of the patients postoperatively (P less than 0.05). These findings suggest that even the short term intubation resulted in the postoperative hoarseness, and this method is a useful and non-invasive bed-side test to evaluate postoperative hoarseness quantitatively.

This study was performed to investigate the effect of sevoflurane, a new inhalation anesthetic, on the respiratory impedance measured by forced oscillation method with random noise input. Random noise (1 to approximately 25Hz) oscillated by a loudspeaker was imposed on the respiratory system of dogs through a tracheostomy and the oscillatory pressure wave and flow wave were monitored at the same point with a pressure transducer and a pneumotachograph. This procedure was repeated during inhalation of 100%-oxygen, 2.0%-then 4.0%-sevoflurane-oxygen mixture, respectively. Impedance was calculated with fast Fourier transform by spectrum analyzer and a personal computer. During inhalation of 4.0%-sevoflurane-oxygen mixture, respiratory impedance especially respiratory resistance decreased at the high frequency area (6to approximately 20Hz), but 2.0%-sevoflurane-oxygen mixture did not cause a significant change of respiratory impedance. This study suggests that inhalation of an anesthetic concentration of sevoflurane produces weak bronchodilation compared with halothane or enflurane.

In this study, we have examined the availability of catheter tip type transducer for the partitioning of respiratory impedance. Total respiratory resistance and reactance from 1 to 20 Hz determined by forced oscillation method with random noise input in anesthetized dogs were partitioned by catheter tip type transducer into central airway resistance (Rc) and reactance (Xc) as well as peripheral resistance (Rp) and reactance (Xp). Intratracheal acetylcholine (0.1g) increased Rp at the wide frequency range (from about 1 to 20 Hz), although Rc did not change with it. The decreases of Rc at higher frequencies (over 12Hz) were produced by intratracheal salbutamol (10mg), whereas Rp did not change significantly. These results suggest that the predominant site of action of intratracheal acetylcholine and salbutamol is peripheral airway and central airway respectively. We have concluded that the respiratory impedance can be partitioned noninvasively with catheter tip type transducer without pneumothorax and hemorrhage caused with the retrograde catheter. This method can be applied clinically during general anesthesia or in intensive care.