Hirotoshi Egawa

The effect of epidural saline injection on analgesic level during combined spinal and epidural anesthesia assessed clinically and myelographically

An epidural injection of physiological saline solution after spinal anesthesia may produce a higher level of analgesia than spinal anesthesia alone because of a volume effect.The purpose of this study was to clarify the volume effect caused by epidural injection of saline after spinal anesthesia. Twenty patients undergoing combined spinal and epidural anesthesia for elective surgery whose analgesic levels did not reach the surgical regions 10 min after spinal anesthesia at the L4-5 interspace were randomly assigned to two groups. The control group (n = 10) received no epidural saline injection. The saline group (n = 10) received 10 mL of saline through an epidural catheter at the L2-3 or L3-4 interspace 10 min after spinal anesthesia. In the saline group, the levels of analgesia 15 and 20 min after spinal anesthesia were significantly higher than those in the control group (P < 0.05). Next, we examined the volume effect of epidural injection of saline with myelography using two adult volunteers. In both volunteers, the upper level of the contrast medium, which was injected in the lumbar subarachnoid space, began to increase concurrently with lumbar epidural injection of saline, reaching from L3 to L1 and from L2 to T12. The diameter of the subarachnoid space diminished to less than 25% after injection of saline. We conclude that lumbar epidural injection of saline increases the analgesic level 10 min after spinal anesthesia, probably because of a volume effect. Implications: In this study, using surgical patients and volunteers, we determined that a lumbar epidural injection of physiological saline solution 10 min after spinal anesthesia produces a higher analgesic level than spinal anesthesia alone because of a volume effect. (Anesth Analg 1997;85:1097-100)

A combination of heparin and an intermittent pneumatic compression device may be more effective to prevent deep-vein thrombosis in the lower extremities after laparoscopic cholecystectomy

BackgroundThe purpose of this study was to clarify the effect of a combination of heparin and an intermittent pneumatic compression device on thrombogenesis and platelet activation in the upper and lower extremities after laparoscopy.MethodsA blinded study was performed on 30 patients. Patients were randomly injected with either heparin or physiological saline solution (PSS) subcutaneously. The intermittent compression boot was used during surgery. Plasma D-dimer (D-D), a, marker of thrombogenesis, and β-thromboglobulin (β-TG), a marker of platelet activation, were measured in the upper and lower extremities.ResultsIn the heparin group, D-Ds in the upper and lower extremities increased significantly 24 h after surgery, but they were significantly lower than those of the PSS group. β-TG in the low-r extremities of patients in the PSS group increased significantly 24 h after surgery.ConclusionA combination of low-molecular-weight heparin and intermittent pneumatic compression may be more effective to prevent deep-vein thrombosis in the legs.

Effects of head-up tilt after stellate ganglion block on QT interval and QT dispersion.

Background and Objectives The aim of this study is to examine the effects of head-up tilt (70°) 30 minutes after right or left stellate ganglion block (SGB) on RR interval, QT interval, the rate-corrected QT (QTc) interval, QT dispersion (QTD), and the rate-corrected QT dispersion (QTcD) using computerized measurement. Methods Ten healthy volunteers underwent both right and left SGBs using 7 mL 1% mepivacaine with a 7-day interval between the two blocks. A 12-lead electrocardiogram was monitored to measure parameters before SGB; 30 minutes after SGB (before head-up tilt); and immediately, 5, 10, and 15 minutes after head-up tilt. Results Right SGB induced significant increases in QT interval, QTc interval, QTD, and QTcD from 30 minutes after the block through 15 minutes after head-up tilt. There were significant increases of QT interval, QTc interval, and QTcD between before and immediately after head-up tilt in right SGB. Left SGB induced significant decreases of QT interval and QTc interval from 30 minutes after SGB through 15 minutes after head-up tilt. Left SGB also induced a significant decrease of QTD from immediately after through 10 minutes after head-up tilt. Conclusions Significant increases of QT interval, QTc interval, and QTcD, which are associated with an increased risk of ventricular arrhythmias and cardiac events, occur immediately after head-up tilt in right SGB. However, head-up tilt does not induce increases of QT interval, QTc interval, QTD, and QTcD in left SGB.

Assessment of QT interval and QT dispersion following stellate ganglion block using computerized measurements.

Background and Objectives Prolongation of QT interval and QT dispersion (QTD) may be associated with an increased risk of arrhythmias. This study was designed to investigate the effects of right or left stellate ganglion block (SGB) on RR interval, QT interval, the rate-corrected QT (QTc) interval, QTD and the rate-corrected QTD (QTcD) using computerized measurements. Methods Ten healthy volunteers underwent both right and left SGBs using 7 mL 1% mepivacaine with a 7-day interval between the 2 blocks. The measurement from the 12-lead electrocardiogram was performed for 60 minutes after SGB. Results Right SGB induced a significant decrease of RR interval immediately after the block, and significant increases of QT interval, QTc interval, QTD, and QTcD from immediately through 50 minutes after the block (P < .01). Left SGB induced a significant decrease of RR interval, and significant increases of QTc interval and QTD immediately after the block (P < .01). Left SGB also produced a significant decrease of QT interval from 20 through 50 minutes after the block, and a significant decrease of QTc interval from 30 through 50 minutes after the block (P < .05). Conclusions Right SGB induces increases of the QT interval, QTc interval, QTD, and QTcD, and left SGB induces decreases of the QT interval and QTc interval.

Assessment of Qt Interval and Qt Dispersion During Electroconvulsive Therapy Using Computerized Measurements

Background: Electroconvulsive therapy (ECT) used in the treatment of severe psychiatric disorders induces stimulation of the autonomic nervous system with initial parasympathetic outflow immediately followed by a sympathetic response. These responses induce an initial bradycardia, arrhythmias, and hypertension. QT dispersion (QTD), defined as maximal QT interval minus minimal QT interval on 12 leads of the surface electrocardiogram, reflects regional heterogeneity of ventricular repolarization. The effects of electrical stimulus due to ECT on QT interval and QTD are of considerable interest. Objective: This study was designed to investigate the effects of electrical stimulation caused by ECT on RR interval, QT interval, the rate-corrected QT (QTc) interval, QTD, and the rate-corrected QTD (QTcD) under general anesthesia using computerized measurements. Methods: Thirty psychiatric patients scheduled for ECT were studied under propofol anesthesia. A 12-lead electrocardiogram was monitored to measure parameters. Muscle paralysis was achieved by administering succinylcholine 1 mg/kg intravenously, and the efficacy of ECT was determined by the tourniquet technique. Results: The RR interval and QT interval decreased significantly immediately after electrical stimulus, and returned to the baseline level 1 minute after electrical stimulus. In 25 out of 30 patients, the baseline value of QTc interval was higher than the normal limits, and the QTc interval decreased significantly for 2 minutes after electrical stimulus. In 27 out of 30 patients, the baseline values of QTD and QTcD were higher than the normal limits, and the QTD and QTcD increased significantly from immediately after electrical stimulus to 5 minutes after electrical stimulus. Conclusions: The QTc interval, QTD, and QTcD, which were associated with increased risks of ventricular arrhythmias, increased significantly before anesthetic induction in patients with major depression. Electrical stimulus during ECT induced further increases of the QTD and QTcD.

High concentration sevoflurane induction of anesthesia accelerates onset of vecuronium neuromuscular blockade

Purpose: To investigate neuromuscular block using accelography after administration of vecuronium under sevoflurane 8% induction and maintenance with sevoflurane 2% in adults.Methods: Patients were allocated to three groups: (1) group I: anesthesia was induced and maintained with propofol and fentanyl (n=15), (2) group II: anesthesia was induced with propofol and maintained with N2O(66%)-O2-sevoflurane 2% (n=15), (3) group III: anesthesia was induced with sevoflurane 8% using a vital capacity inhalation induction and maintained with N2O(66%)-O2-sevoflurane 2% (n=15). 0.1 mg·kg−1 vecuronium was used for paralysis three minutes after anesthetic induction and reversed using intravenous 0.04 mg·kg−1 neostigmine with 0.02 mg·kg−1 atropine when the train-of-four (TOF) ratio returned to 25%.Results: The onset time from initial administration of vecuronium to maximal block in the group III was shorter than that in the groups I and II (139±35, 193±35 and 188±47s, respectively:P<0.05). The clinical duration from maximal block to 25% recovery of TOF ratio in group II and III was longer than that in the group I (47±15, 48±14 and 36±10 min, respectively:P<0.05). The reversal times from administration of neostigmine to 75% of TOF ratio in groups II and III were longer than that in the group I (196±53, 208±64 and 136±28s, respectively:P<0.05).Conclusions: Vital capacity inhalation induction of anesthesia with sevoflurane accelerates onset and prolongs duration of vecuronium neuromuscular block compared with propofol-fentanyl anesthesia.RésuméObjectif: Étudier le blocage neuromusculaire à l’aide de l’accélographie après l’administration de vécuronium pendant l’anesthésie induite avec du sévoflurane à 8% et maintenue avec du sévoflurane à 2% chez des adultes.Méthode: Les patients ont été répartis en trois groupes: le groupe I: l’anesthésie est induite et maintenue avec du propofol et du fentanyl (n=15); le groupe II: l’anesthésie est induite avec du propofol et maintenue avec N2O(66%)-O2-sévoflurane 2% (n=15); le group III: l’anesthésie est induite avec du sévoflurane à 8% en utilisant la technique de la capacité vitale et maintenue avec N2O(66%)-O2-sévoflurane 2% (n=15). Une dose de 0,1 mg·kg−1de vécuronium a été utilisée pour provoquer le bloc, trois minutes après l’induction anesthésique. Ce bloc a été renversé avec une dose intraveineuse de 0,04 mg·kg−1 de néostigmine avec 0,02 mg·kg−1 d’atropine quand le train-de-quatre (TDQ) était revenu à 25%.Résultats: Le délai d’installation, de l’administration initiale de vécuronium jusqu’au bloc maximal, a été plus court dans le groupe III que dans les groupes I et II (139±35, 193±35 et 188±47s, respectivement:P<0,05). La durée clinique, du bloc maximal jusqu’à une récupération de 25% du ratio du TDQ, a été plus longue dans les groupes II et III que dans le groupe I (47±15, 48±14 et 36±10 min, respectivement:P<0,05). Le temps de renversement du bloc, de l’administration de néostigmine jusqu’au retour de 75% du ratio du TDQ, a été plus long dans les groupes II et III que dans le groupe I (196±53, 208±64 et 136±28s, respectivement:P<0,05).Conclusion: L’induction de l’anesthésie par inhalation avec du sévoflurane, selon la technique de la capacité vitale, permet un début d’action plus rapide et prolonge la durée du bloc neuromusculaire réalisé avec du vécuronium comparé au mélange de propofol et de fentanyl.

QT interval and QT dispersion increase in the elderly during laparoscopic cholecystectomy: a preliminary study

PurposeTo compare the influence of a longer duration of intraperitoneal CO2 insufflation with head-up tilt on electrocardiogram indices during laparoscopic cholecystectomy between elderly and younger patients.MethodsTwelve elderly and 12 younger patients were studied. In all patients, intraperitoneal CO2 insufflation was performed for more than 150 min in the head-up position. RR interval, QT interval, the rate-corrected QT (QTc) interval, QT dispersion (QTD) and the rate-corrected QTD (QTcD) were measured.ResultsThe QT interval and the QTc interval increased significantly from 120 to 150 min after CO2 insufflation in the elderly. The QTD and QTcD increased significantly during CO2 insufflation in both groups. Those were significantly greater in the elderly than in younger patients from 120 to 150 min after CO2 insufflation.ConclusionLonger duration of CO2 insufflation with head-up tilt is associated with a prolongation of the QT interval and the QTD in elderly patients. The clinical significance of these findings remains to be determined.RésuméObjectifComparer l’influence d’une insufflation intrapéritonéale prolongée de CO2 en position de Fowler, sur les indices de l’électrocardiogramme pendant la cholécystectomie laparoscopique, entre les patients âgés et de jeunes patients.MéthodeDouze patients âgés et douze jeunes patients ont participé à l’étude, L’insufflation de CO2 a été réalisée pendant plus de 150 min en position de Fowler chez tous les patients. L’intervalle RR, l’intervalle QT, l’intervalle QT corrigé pour la fréquence (QTc), la dispersion QT (QTd) et la QTd corrigée pour la fréquence (QTcD) ontété mesurés.RésultatsL’intervalle QT et l’intervalle QTc ont augmenté significativement de 120 à 150 min après l’insufflation de CO2 chez les patients âgés. Le QTD et le QTcD ont augmenté de façon significative pendant l’insufflation de CO2 chez tous les patients. Ces résultats ont été plus élevés chez les patients âgés comparés aux jeunes patients, entre 120 et 150 min après l’insufflation de CO2.ConclusionUne insufflation prolongée de CO2 en position de Fowler est associée à des intervalles QT et QTD également prolongés chez les patients âgés. La portée clinique de ces résultats demeure indéterminée.

Bispectral monitoring during vital capacity rapid inhalation induction with sevoflurane

STUDY OBJECTIVE To evaluate the variables of bispectral index (BIS) values during vital capacity rapid inhalation induction (VCRII) with sevoflurane. DESIGN Randomized, prospective study. SETTING University hospital. PATIENTS 40 ASA physical status I and II patients scheduled for elective orthopedic surgery with general anesthesia. INTERVENTIONS Patients was divided into two groups, both of which received intravenous (IV) injection of propofol 2 mg/kg followed by inhalation of sevoflurane 3% (Group P), or vital capacity inhalation induction with sevoflurane 8% (Group S). After loss of consciousness, tracheal intubation was performed with vecuronium 0.1 mg/kg. MEASUREMENTS AND MAIN RESULTS The induction times in Group P were significantly shorter than those in Group S (p < 0.01). In Group S, BIS values were gradually decreased and maintained the adequate hypnotic levels were maintained during induction. In Group P, although BIS values were rapidly decreased, the values remained higher compared with Group S. The BIS value before intubation in Group S was significantly lower than that in Group P (25 +/- 9 and 38 +/- 7, respectively; p < 0.01). Five of 20 Group P patients had BIS values exceeding 60 before tracheal intubation, but no patient in Group S had a BIS value as high. Mean arterial pressure immediately after intubation in Group S was significantly lower than that in Group P (p < 0.05). CONCLUSION VCRII with a high concentration of sevoflurane provided adequate BIS values during induction, suggesting that it may allow smoother transition from anesthesia induction to maintenance, and also maintain an adequate hypnotic level in readiness for certain stimuli such as laryngoscopy and tracheal intubation.

Use of a fiberscope and closed-circuit television for teaching laryngeal mask insertion.

The laryngeal mask often allows adequate ventilation, even if the mask position is suboptimal. However, it is important to master correct positioning of the mask, because a suboptimally positioned mask is associated with increased risk of complications and with difficulty in intubating the trachea through it (1–3). Fiberscopy after insertion of the laryngeal mask can help assess the mask position and has been reported to be useful for training (4). One problem with this method is that if ventilation through the laryngeal mask has failed, it may be practically difficult to assess the cause of the failure, because fiberscopy after insertion of the mask prolongs apnea time. Therefore, the cause of failed ventilation is often not elucidated. We suggest that after a fiberscope, which is connected to a closed-circuit television, is inserted into the laryngeal mask, the mask is inserted while the fiberoptic view is being shown on the television (Figure 1). This method enables one to see the anatomical course of the mask, in relation to the tongue, epiglottis or glottis during insertion. The cause for airway obstruction, if any, can be detected without prolonging the apnea time.