Renin-aldosterone system and atrial natriuretic peptide during anesthesia in orthopedic patients over 80 years of age

STUDY OBJECTIVES

To investigate the changes in plasma atrial natriuretic peptide, renin activity, and aldosterone during isoflurane anesthesia in patients over 80 years.

DESIGN

Prospective, randomized, controlled study.

SETTING

Operating rooms and postanesthesia recovery room of Hirosaki University Hospital and Hakodate Watanabe Hospital.

PATIENTS

36 patients undergoing reduction of femur neck fracture (18 patients ranging in age from 80 to 99 years and 18 patients ranging in age from 40 to 59 years as control).

INTERVENTION

In all patients, anesthesia was induced with intravenous (i.v.) thiopental sodium 3 to 5 mg/kg succinylcholine 0.5 to 1.0 mg/kg for facilitating tracheal intubation and was maintained with 1.2% to 2.0% isoflurane in 50% oxygen.

MEASUREMENTS AND MAIN RESULTS

Plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA), and plasma aldosterone (PA) levels were assayed. Blood samples were obtained on the following occasions: before the induction of anesthesia, 15 minutes after skin incision, 90 minutes after anesthesia induction, and the 60 minutes after the end of surgery. Plasma renin activity and PA levels in patients from 40 to 59 years increased significantly 90 minutes after induction, whereas PRA and PA levels in patients over 80 years were unchanged. There were significant differences in PRA and PA levels between both groups at any time of measurements. Plasma ANP levels of patients over 80 years were significantly elevated at 90 minutes induction. Plasma ANP levels in patients over 80 years at 90 minutes after the induction and 60 minutes after the end of surgery were significantly higher than those of patients from 40 to 59 years. Plasma renin activity in hypertensive patients over 80 years at 90 minutes after the induction was significantly lower than that observed in normotensive patients. The renal loss of sodium was increased in the hypertensive patients.

CONCLUSIONS

Orthopedic patients over 80 years of age have decreased PRA and PA, increased ANP, and renal loss of sodium as compared with patients 40 to 59 years, during isoflurane anesthesia. Plasma renin activity at 90 minutes after induction was decreased in hypertensive patients over 80 years, but PA and ANP were not affected by hypertension during anesthesia.

Detection of histamine-induced capillary protein leakage and hypovolaemia by determination of indocyanine green and glucose dilution method in dogs

OBJECTIVE

The plasma volume of histamine-induced protein capillary leakage may be overestimated when this is determined using the indocyanine green (ICG) dilution method (Vd-ICG), since this dye binds to plasma proteins. The initial distribution volume of glucose (IDVG) has been shown to indicate the central extracellular fluid volume including plasma. Accordingly, the overestimation would be detected by a higher Vd-ICG/IDVG ratio. Our study was intended to examine whether the simultaneous measurement of these two variables can evaluate histamine-induced protein leakage and associated hypovolaemia.

DESIGN

Prospective animal study.

SETTING

Institutional animal research laboratory.

SUBJECTS

Twenty-four anaesthetized and ventilated mongrel dogs.

INTERVENTIONS

Anaesthetized animals were mechanically ventilated and received infusions of normal saline (n = 8), histamine 50 microg/kg per h (n = 8), or histamine 100 microg/kg per h. The Vd-ICG and IDVG were calculated using a one-compartment model by simultaneous administration of ICG 0.5 mg/kg, and glucose 100 mg/kg followed by serial arterial blood sampling.

MEASUREMENTS AND RESULTS

In both histamine groups, a significant elevation of haematocrit and a decrease of plasma albumin concentration were found (p<0.05). Although the IDVG decreased following histamine administration (p<0.05), the Vd-ICG remained unchanged. The Vd-ICG/IDVG ratio increased in a dose-dependent manner after histamine administration (p<0.05), but remained unchanged following normal saline administration.

CONCLUSION

The results suggest that the Vd-ICG/IDVG ratio and the IDVG are useful in evaluating the magnitude of the leakage and hypovolaemia.

Mutations in the p53 and scid genes do not cooperate in lymphomagenesis in doubly heterozygous mice

Analysis of double mutant mice of the p53 and scid genes, which have a combination of cell cycle checkpoint/apoptosis and DNA repair defects, shows that the latter defect synergistically enhances lymphoma development with loss of the former function. These mice lack the ability to eliminate lymphocytes predisposed to neoplastic transformation resulting from faulty antigen receptor gene rearrangement. Here we examine the cooperativity in double heterozygotes of p53 and scid in which normal development of lymphocytes is not impaired. MSM mice carrying a p53-knockout allele were crossed with BALB/c mice heterozygous for the scid locus and 129 offspring were obtained. They were subjected to gamma-ray irradiation, 84 thymic lymphomas being generated. The tumors and host mice were genotyped of p53 and scid. Among 42 mice developing p53-deficient lymphomas, scid/+ and +/+ genotypes did not provide difference in onset and latency. Besides, allelic loss of the Scid gene occurred at a high frequency in those lymphomas but the loss exhibited no allelic bias. The results suggest that the scid/+ genotype is not a modifier of loss of p53 function in the double heterozygotes.

[Total intravenous anesthesia for two patients complicated with myotonic dystrophy]

Total intravenous anesthesia with propofol, fentanyl and ketamine (PFK) was given to two patients complicated with myotonic dystrophy. Case-1: A 42-year-old female underwent a hemithyroidectomy. Anesthesia was induced slowly with intravenous ketamine 20 mg and propofol 60 mg. Her tracheal intubation was performed smoothly without any muscle relaxants. Anesthesia was maintained with propofol infusion of 5 mg.kg-1.h-1, ketamine infusion of 0.3 mg.kg-1.h-1 and fentanyl 200 micrograms in total. She regained consciousness 20 minutes after the end of propofol infusion, and 15 minutes later, her trachea was extubated without any troubles. Case-2: A 41-year-old female underwent a removal of left parotid tumor. Anesthesia was induced slowly with ketamine 40 mg and propofol 100 mg intravenously. Anesthesia was maintained with propofol infusion of 5-10 mg.kg-1.h-1, ketamine infusion of 0.5 mg.kg-1.h-1 and fentanyl 350 micrograms in total. No muscle relaxant was used through the surgical procedure. Emergence from anesthesia was observed 10 minutes after the end of propofol infusion and her trachea was extubated. When a nasogastric tube was pulled out, her respiration stopped suddenly and she was intubated again only for two hours without any troubles. In both cases their serum CPK levels and rectal temperatures were very stable. PFK method would be a choice for patients with myotonic dystrophy.

The effect of ketamine on clinical endpoints of hypnosis and EEG variables during propofol infusion

BACKGROUND

We studied the effect of variable doses of ketamine on the endpoints of hypnosis, e.g., unresponsiveness to verbal commands (UVC), loss of eyelash reflex (LER), and inhibition of body movement response with or without sneezing to nasal membrane stimulation (INBMR), and processed EEG variables, e.g., bispectral index (BIS), 95% spectral edge frequency (SEF) and median frequency (MF) during propofol infusion.

METHODS

Forty-eight patients received either propofol infusion, 30 mg.kg-1.h-1 (Group P; n = 12) or ketamine bolus, 0.25, 0.5 or 0.75 mg i.v., followed by propofol infusion, 30 mg.kg-1.h-1 + variable dose ketamine infusion, 0.25, 0.5 or 0.75 mg.kg-1.h-1 (Groups PK0.25, PK0.5 and PK0.75; n = 12 each) until UVC, LER and INBMR. BIS, 95% SEF and MF values were monitored and recorded at the endpoints of hypnosis. Propofol and ketamine concentrations were measured at INBMR.

RESULTS

Propofol infusion, 30 mg.kg-1.h-1, induced UVC, LER and INBMR at BIS: 65 +/- 2, 63 +/- 9 and 33 +/- 7; 95% SEF: 17 +/- 3, 17 +/- 4 and 14 +/- 3; and MF values of 5 +/- 2, 5 +/- 3 and 3 +/- 2, respectively. With adjunctive ketamine (Groups PK0.5 and PK0.75), the hypnotic endpoints were achieved at higher BIS and 95% SEF values and lower propofol doses and concentrations as compared to Groups P and PK0.25 (9.9 +/- 5.8 and 9.4 +/- 3.4 vs. 13.4 +/- 4.5 and 14 +/- 5.8 micrograms.ml-1).

CONCLUSIONS

Our results suggest additive interaction between propofol and ketamine (Groups PK0.5 and PK0.75) for achieving the hypnotic endpoints; however, ketamine did not depress the EEG variables in proportion to its hypnotic effect. The paradoxically higher BIS and 95% SEF values at the hypnotic endpoints may be due to lower propofol concentrations and/or no effect of ketamine on the EEG variables.

I.v. lidocaine worsens histamine-induced bronchoconstriction in dogs

We have assessed the effect of lidocaine (lignocaine) on histamine-induced bronchoconstriction by direct visualization with a superfine fibreoptic bronchoscope. Seven mongrel dogs were anaesthetized with pentobarbital (pentobarbitone) 30 mg kg-1 followed by 2 mg kg-1 h-1 and pancuronium 200 micrograms kg-1 h-1. The trachea was intubated with a tracheal tube containing a second lumen for insertion of a 2.2-mm fibreoptic bronchoscope. This allowed estimation of the bronchial cross-sectional area (BCA) of the third bronchial bifurcation of the right lung. We used NIH image, a public domain image processing and analysis program. Bronchoconstriction was produced with a bolus dose of histamine 10 micrograms kg-1 i.v. followed by continuous infusion of 500 micrograms kg-1 h-1. After 30 min the following i.v. doses of lidocaine were given: lidocaine 0 (saline), 0.01, 0.1, 1.0 and 10 mg kg-1 at 10-min intervals. BCA was assessed 90 s after each dose. Arterial blood sampling was performed for measurement of plasma catecholamines. Lidocaine 1.0 and 10 mg kg-1 significantly reduced histamine-decreased BCA from 69.7 (SEM 4.1)% to 59.8 (7.3)% and 34.3 (6.8)%, respectively. Plasma concentrations of catecholamines decreased significantly after lidocaine 10 mg kg-1 i.v. In addition, there was a significant correlation between percentage decreases in plasma concentrations of epinephrine (adrenaline) and norepinephrine (noradrenaline) and reduction in %BCA (epinephrine-BCA, P < 0.01, r = 0.674; norepinephrine-BCA, P < 0.01, r = 0.510). This study suggests that i.v. lidocaine may exacerbate histamine-induced bronchoconstriction by a sympatholytic effect. This may have therapeutic implications for patients with acute asthma or anaphylactic shock who may become dependent on circulating catecholamines.

Hypnotic endpoints vs. the bispectral index, 95% spectral edge frequency and median frequency during propofol infusion with or without fentanyl

Hypnotic endpoints and/or EEG variables, e.g. bispectral index, 95% spectral edge frequency and median frequency, have been studied to monitor anaesthetic (hypnotic) depth during total intravenous anaesthesia. In this study, the relation between the hypnotic endpoints of unresponsiveness to verbal commands, loss of eyelash reflex and body movement response to mechanical nasal membrane stimulation vs. bispectral index, 95% spectral edge frequency and median frequency during propofol anaesthesia with or without fentanyl is presented. Forty-two patients were randomly assigned to receive either propofol infusion, 30 mg kg-1 h-1 (n = 22), or propofol infusion, 30 mg kg-1 h-1 + fentanyl bolus, 2 micrograms kg-1 i.v. (n = 20). Bispectral index, 95% spectral edge frequency and median frequency and propofol doses were monitored and recorded at unresponsiveness to verbal commands, loss of eyelash reflex and inhibition of nasal body movement response. The bispectral index values were significantly higher in the propofol + fentanyl compared with the propofol group, i.e. 74.7 +/- 10.9, 73.1 +/- 10.5 and 47.1 +/- 9.2 vs. 65.8 +/- 9.8, 59.6 +/- 10 and 33.8 +/- 5.7 at unresponsiveness to verbal commands, loss of eyelash reflex and inhibition of nasal body movement response respectively. Doses of propofol for achieving the hypnotic endpoints were significantly lower in the propofol + fentanyl compared with the propofol group. Plasma propofol concentrations at inhibition of nasal body movement response were lower in the propofol + fentanyl compared with the propofol group (9.2 +/- 2.0 micrograms mL-1 vs. 14.1 +/- 4.2 micrograms mL-1). Our results suggest that fentanyl pretreatment potentiates the effects of propofol and achieves the hypnotic endpoints at higher bispectral index values and lower propofol doses and concentrations (measured at inhibition of nasal body movement response).

The role of the N-methyl-D-aspartic acid receptor in the relaxant effect of ketamine on tracheal smooth muscle

Ketamine and magnesium (Mg2+), well known bronchodilators, have been used to treat patients with status asthmaticus. Both can block the N-methyl-D-aspartic acid (NMDA) receptor. NMDA receptors exist in the airway, and their activation seems to be linked to the release actions of sensory neuropeptides resulting in increased airway tone. We sought to determine whether ketamine relaxes the guinea pig trachea contracted by histamine by blocking the NMDA receptor. Female guinea pigs (250-400 g) were killed with an overdose of pentobarbital. The trachea was removed and cut spirally into strips 3 mm wide and 15 mm long. The strips were mounted in a 10-mL organ bath filled with Tyrode's solution bubbled through with 95% O2/5% CO2 at 37 degrees C. Strip contractions were measured isometrically with a force displacement transducer. We then studied the effect of NMDA receptor antagonists on histamine-induced tracheal contraction. In this protocol, we examined the effect of ketamine, Mg2+, zinc (Zn2+), or MK-801 (a noncompetitive NMDA receptor blocker) on strips contracted by 10(-5) M histamine. After full contraction was attained, ketamine (0.5-1.5 mM), MgSO4 (2-8 mM), ZnCl2(0.2-0.8 mM), or MK-801 (1.5-6 x 10(-5) M) was added, and the strip tension was measured again. We also studied the effect of NMDA on the relaxation by ketamine. After full contraction by 10(-5) M histamine, 0.5-1.5 mM KET was added alone or in combination with 0.1 mM NMDA, and the strip tension was measured again. Finally, we measured the effect of MK-801 on the relaxant effect of ketamine. After full contraction by 10(-5) M histamine, 0.5-2 mM ketamine was added alone or in combination with 0.75 or 1.5 x 10(-5) M MK-801, and the strip tension was measured again. All NMDA receptor antagonists tested reversed the tracheal contraction induced by histamine in a dose-dependent manner. However, neither the agonist NMDA nor the noncompetitive receptor blocker MK-801 affected tracheal relaxation induced by ketamine. We conclude that ketamine relaxes the tracheal smooth muscle contracted by histamine through a mechanism independent of NMDA receptors. The decreased bronchomotor tone induced by ketamine is probably due to interference with a Ca2+-requiring step necessary to maintain the contraction caused by histamine.

IMPLICATIONS

Stimulation of the N-methyl-D-aspartic acid (NMDA) receptor in the airway results in airway constriction. The bronchodilator ketamine blocks the NMDA receptor. However, ketamine relaxes the guinea pig trachea contracted by histamine through a mechanism independent of the NMDA receptor.

Intraoperative modulation of alveolar macrophage function during isoflurane and propofol anesthesia

BACKGROUND

Alveolar macrophages are a critical part of the defense against pulmonary infection. Thus the authors determined time-dependent changes in alveolar macrophage functions in patients having surgery who were anesthetized with isoflurane or propofol.

METHODS

Patients anesthetized with propofol (n = 30) or isoflurane (n = 30) during orthopedic surgery were studied. Alveolar macrophages were harvested by bronchoalveolar lavage immediately, and 2, 4, and 6 h after induction anesthesia and at the end of surgery. The fraction of aggregated and nonviable macrophages was determined. Then phagocytosis was measured by ingestion of opsonized and unopsonized particles. Finally, microbicidal activity was determined as the ability of the macrophages to kill Listeria monocytogenes directly.

RESULTS

Demographic and morphometric characteristics of the patients given propofol and isoflurane were similar, as were their levels of pulmonary function and hemodynamic responses. The fraction of alveolar macrophages ingesting opsonized and unopsonized particles, and the number of particles ingested, decreased significantly over time, with the decrease slightly but significantly greater during isoflurane anesthesia. Microbicidal function decreased progressively during anesthesia and surgery, with the decrease almost twice as great during isoflurane compared with propofol anesthesia. The fraction of aggregated macrophages and recovered neutrophils increased over time in the patients given each anesthetic.

CONCLUSIONS

Pulmonary immunologic function changed progressively during anesthesia and surgery. The data from this study suggest that pulmonary defenses are modulated by the type of anesthesia and by the duration of anesthesia and surgery.

[Effect of propofol as an agent for anesthetic induction on pituitary-adrenocortical function during anesthesia and surgery]

Effect of propofol as an agent for anesthetic induction on plasma levels of cortisol, beta-endorphin-like immunoreactivity (beta-ELI), growth hormone (GH) and prolactin were evaluated in 20 non-abdominal surgical patients ranged in ages from 19 to 64 years. Anesthesia was induced with either intravenous propofol 2-2.5 mg in ten patients or intravenous thiopental 4-5 mg in the remaining 10 patients as the control group, and succinylcholine was administered intravenously to facilitate tracheal intubation. Enflurane-nitrous oxide-oxygen was then given to maintain anesthesia in all the patients of both groups. Plasma cortisol levels decreased slightly with anesthesia in the propofol group, but they increased slightly after anesthetic induction in the control group. Therefore they were significantly lower in the propofol group than those in the control group. They tended to increase gradually during surgery and reached the peak value after the emergence from anesthesia in both groups. Plasma beta-ELI levels were unchanged with anesthesia alone in the patients of both groups. They tended to increase gradually during surgery and reached the peak value after the emergence from anesthesia in both groups. Plasma GH levels were not affected with anesthesia, but they increased slightly during surgery in both groups. Plasma prolactin levels increased significantly during anesthesia and surgery in both groups, and they decreased after the emergence from anesthesia but were still significantly higher than the preanesthetic values in both groups. The authors' findings suggest that effects of propofol as an agent for anesthetic induction on pituitary-adrenocortical function during anesthesia and surgery are comparable to those of thiopental, and that propofol does not exert inhibitory effect on pituitary-adrenocortical function during anesthesia and surgery.

[Electroconvulsive therapy decreased bispectral index--a case report]

A 28-year old female schizophrenic patient underwent electroconvulsive therapy (ECT) under propofol anesthesia. She received ECT five times, and Bispectral Index (BIS) was recorded four times out of the five ECT. BIS values (mean +/- SD) were 95.3 +/- 1.3 before anesthesia, 38.0 +/- 13.1 after loss of consciousness, 45.3 +/- 12.7 immediately after ECT and 27.3 +/- 11.6 about two minutes after ECT. In conclusion, ECT may decrease BIS during continuous propofol infusion.

Detection of capillary protein leakage by glucose and indocyanine green dilutions during the early post-burn period

Overestimation of the plasma volume determined by the indocyanine green (ICG) dilution method (PV-ICG) may occur after burns, since this dye has the potential of extravasation in the presence of the capillary protein leakage. Assuming that the initial distribution volume of glucose (IDVG) consistently indicates the extracellular fluid volume of highly perfused organs including plasma, overestimation of the PV-ICG can be detected by a higher PV-ICG/IDVG ratio. The present study was designed to test whether a higher PV-ICG/IDVG ratio is observed within 24 h post-burn compared to the subsequent days. Ten severely burned adult patients admitted to the ICU were studied through the 2nd post-burn day. The daily IDVG and PV-ICG were calculated using a one compartment model by simultaneous administration of glucose, 5 g, and ICG, 25 mg. Although the IDVG increased on the 1st post-burn day (p < 0.05), the PV-ICG remained unchanged. The PV-ICG/IDVG ratio within 24 h post-burn was significantly higher than that on the 1st post-burn day (p < 0.01). Results indicate that overestimation of the PV-ICG can occur within 24 h post-burn and suggest that simultaneous measurement of the IDVG and the PV-ICG would help predict the generalized capillary protein leakage after burns.

[Two cases of circulatory failure after local infiltration of epinephrine during tonsillectomy]

We experienced two cases of circulatory failure after local infiltration of 0.0005% epinephrine solution for the purpose of prophylactic hemostasis during tonsillectomy under sevoflurane anesthesia. Case 1: A 14 year-old girl developed ventricular bigeminy, tachycardia and hypertension following infiltration of the epinephrine solution 6ml around the tonsil. Sinus rhythm returned with intravenous lidocaine 40 mg and propranolol 0.4 mg. However, the patient showed gradually decreasing heart rate, depressed ST segments and inverted T waves and poor peripheral circulation. Her blood pressure decreased abruptly at the same time and finally the pulsation of the radial and femoral arteries was not palpable. She was treated with intravenous ephedrine in vain. Therefore, she received intravenous epinephrine and cardiac massage, and then recovered from the circulatory failure with her ECG showing normal sinus rhythms. Emergence from the anesthesia was smooth. Her cardiac failure may have been caused by the decreasing cardiac contraction and the increasing afterload due to the vasoconstriction after the intravenous beta-blocker. Case 2: An eleven year-old boy showed ventricular tachycardia and hypertension after infiltration of the epinephrine solution 11.5 ml around the tonsil. Lidocaine was given intravenously. This restored sinus rhythm but the ST segments on his ECG were elevated. ST segments became normalized after intravenous nitroglycerin. However, pulmonary edema developed suddenly, and it was cured by intensive treatment. His ventricular tachycardia and hypertension after the local administration of epinephrine were presumably responsible for the acute heart failure causing the pulmonary edema. Our experience suggests that the maintenance of cardiac function and the reduction of afterload are important to overcome the circulatory disaster following the local infiltration of epinephrine.

Ratio of indocyanine green and glucose dilutions detects capillary protein leakage following endotoxin injection in dogs

This study was designed to determine whether endotoxin-induced generalized capillary protein leakage can be detected using the ratio of indocyanine green (ICG) and glucose dilutions. Plasma volume determined by the ICG dilution method (Vd-ICG) and the initial distribution volume of glucose (IDVG) were assessed simultaneously before and after either the administration of lipopolysaccharide (LPS) 0.3 mg kg-1 or equal amounts of isotonic saline in two groups of eight dogs, using a one-compartment model after simultaneous infusions of both ICG 0.5 mg kg-1 and glucose 100 mg kg-1. The IDVG has been shown to indicate the extracellular fluid volume of highly perfused organs including plasma. All post-treatment values decreased compared with the pre-treatment values (P < 0.05), except Vd-ICG in the LPS group, even though the post-treatment total plasma protein concentration of the LPS group decreased significantly compared with the pre-treatment value (P < 0.05). The post-treatment Vd-ICG/IDVG ratio of the saline group remained unchanged compared with that of the pre-treatment, and the post-treatment ratio of the LPS group increased significantly (P < 0.01). It can be concluded that overestimation of the Vd-ICG can occur after endotoxin injection, which can be detected by simultaneous measurements of the Vd-ICG and the IDVG.

Effects of thiopental on airway calibre in dogs: direct visualization method using a superfine fibreoptic bronchoscope

Induction of anaesthesia with thiopental sometimes causes bronchospasm. Although the mechanism by which thiopental induces bronchospasm may involve cholinergic stimulation, direct spastic effect and histamine release, the spastic effects of thiopental have not been comprehensively defined. In this study, we have assessed the effect of thiopental on in vivo airway smooth muscle tone using direct visualization method with a superfine fibreoptic bronchoscope as previously reported. Twenty-one mongrel dogs were anaesthetized with pentobarbital (30 mg kg-1) and paralysed with pancuronium (200 micrograms kg-1 h-1). The trachea was intubated with a tube that had a second lumen for insertion of the bronchoscope (od: 2.2 mm) to continuously measure bronchial cross-sectional area. The tip of the bronchoscope was placed between the second and third bronchial bifurcation of the right lung. The dogs were allocated to three groups of seven: group T, A+T, H+T. In group T, thiopental 0 (saline), 0.1, 1.0 and 10 mg kg-1 was given i.v. In group A+T, saline i.v., 5 min later atropine 0.1 mg kg-1 i.v., and 5 min later thiopental 10 mg kg-1 was administered. In group H+T, bronchoconstriction was produced with histamine 10 micrograms kg-1 i.v. followed by infusion at 500 micrograms kg-1 h-1. Thirty minutes later, thiopental 0, 1.0 and 10 mg kg-1 were given. Arterial blood sampling was performed for measurement of plasma catecholamines and histamine. In group T, thiopental significantly reduced bronchial cross-sectional area (maximally by 28.7 (5.6% at 0.5 min after thiopental 10 mg kg-1), which returned to the baseline in 3 min, while any changes in plasma concentrations of catecholamines and histamine were not observed except norepinephrine level at 1 min following thiopental 10 mg kg-1 i.v. Atropine pretreatment completely prevented thiopental-induced bronchospasm in group A+T. In group H+T, thiopental 10 mg kg-1 transiently but significantly decreases bronchial cross-sectional area. Therefore, the present study indicates that the mechanism of thiopental bronchospasm may result from cholinergic nerve stimulation.

Inhibited hypothalamic histamine metabolism during isoflurane and sevoflurane anesthesia in rats

BACKGROUND

Histamine is most densely distributed in the hypothalamus and has an important effect on consciousness or wakefulness. It has been little considered whether general anesthetics could exert their effects on hypothalamic histamine metabolism. The present study was conducted to investigate the effects of isoflurane and sevoflurane anesthesia on hypothalamic histamine metabolism.

METHODS

Sixty male Wistar rats were divided equally into isoflurane and sevoflurane anesthesia groups. Each group was divided into three equal sub-groups: the control, anesthesia and recovery groups. The rats of the anesthesia and recovery groups were exposed to either 2% isoflurane or 3% sevoflurane for 30 min. The recovery group was kept in air for 30 min after anesthesia. The rats were decapitated to dissect out hypothalamus which was divided into the fore and rear portion. The contents of histamine and 1-methylhistamine, which is a main histamine metabolite, were determined by high-performance liquid chromatography. The obtained data were analyzed by one-way analysis of variance followed by Bonferoni's test.

RESULTS

Histamine contents of the anterior and posterior hypothalamus in both isoflurane and sevoflurane groups increased significantly during the anesthesia and 1-methylhistamine contents of the anterior and posterior hypothalamus in sevoflurane group increased remarkably after anesthesia. The increases of histamine contents supposedly reflected inhibited histamine metabolism and the increases of 1-methylhistamine would be caused by acceleration of histamine degradation.

CONCLUSIONS

Histamine metabolism was inhibited during both isoflurane and sevoflurane anesthesia and accelerated only in the posterior hypothalamus during the emergence from these anesthetics.

Ketamine inhibits the tonic response to carbachol and histamine in the guinea pig trachea

The contractile response of smooth muscles to spasmogens can be divided into two components by modifying the extracellular Ca2+ concentration. The phasic component depends on the mobilization of Ca2+ from intracellular stores whereas the tonic component depends, to a large extent, on the influx of extracellular Ca2+. The present study was designed to investigate the effect of ketamine on the tonic response to carbachol or histamine in the guinea pig trachea. Tracheal spirals from female guinea pigs were mounted in organ baths filled with aerated physiological buffer, and their isometric tension was measured. The phasic response to 10(-7) M carbachol or 10(-5) M histamine in Ca(2+)-free, ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid-containing buffer and the tonic response to each spasmogen after restoring [Ca2+] in the buffer was measured in the absence or presence of ketamine. In the presence of normal physiological buffer, ketamine decreased the contractions induced by carbachol or histamine in a dose-dependent fashion. No measurable phasic response to either carbachol or histamine was obtained in our preparation. Ketamine (5 x 10(-5) M-10(-3) M) reduced the tonic response to 10(-7) M carbachol to 79.5 +/- 2.7-4.3 +/- 0.7% of the response without ketamine. Similarly, ketamine (5 x 10(-4) M-2 x 10(-3) M) decreased the tonic response to 10(-5) M histamine to 80.7 +/- 3.9-23.0 +/- 3.2% of the response in the absence of ketamine. Our findings support the hypothesis that ketamine inhibits the paracrine agent-induced contractions of smooth muscles by interfering with the influx of extracellular Ca2+ or with an intracellular event(s) requiring extracellular Ca2+.

Effect of carbamazepine on pain scores of unipolar depressed patients with chronic pain: a trial of off-on-off-on design

OBJECTIVE

The purpose of this study was to evaluate the effect of carbamazepine on chronic pain in patients with major depression.

DESIGN

Off-on-off-on carbamazepine treatment design.

SETTING

Department of Anesthesiology, Hirosaki University Hospital, Japan.

PATIENTS

Fifteen patients with a diagnosis of major depression and chronic pain.

INTERVENTION

Depressed patients maintained on antidepressants that had failed to help depression or pain were initially placed on 450 mg carbamazepine at 150 mg three times per day. Carbamazepine was then increased until the patients experienced satisfactory relief of pain. This dose was then maintained for 3 weeks. Afterward, the medication was stopped, and a lactose placebo was administered orally three times per day for 3 weeks. Thereafter, carbamazepine was given for 3 additional weeks at the dose that previously produced satisfactory pain relief.

OUTCOME MEASURE

Pain scores were assessed four times during the course of the study: before and after the first and the second treatments with carbamazepine, using a visual analog scale in which 0 represents no pain and 10 unbearable pain. The Hamilton Depression scale was used to judge improvement in the symptoms of depression.

RESULTS

Carbamazepine produced a statistically significant reduction in the pain scores, from 8.2 +/- 2.3 to 4.0 +/- 1.1 after the first treatment. The pain score significantly increased to 8.0 +/- 1.0 after stopping carbamazepine, but it decreased significantly to 4.1 +/- 1.8 after the second treatment. The Hamilton scores significantly decreased from 27.4 +/- 7.2 to 20.2 +/- 6.1 after the carbamazepine treatment.

CONCLUSIONS

These results may indicate that carbamazepine has both an antidepressive and an analgesic action in depressed patients. Thus, carbamazepine may offer an acceptable therapeutic option in depressed patients with chronic pain that is unresponsive to antidepressants. Alternatively, these results may indicate that carbamazepine appears to help depression in this group of pain patients because of its analgesic effect (i.e., helps depression as a result of helping pain or vice versa).

[Pharmacokinetics of propofol and ketamine during and after total intravenous anesthesia with propofol, fentanyl and ketamine for pediatric patients]

Pharmacokinetics of propofol and ketamine during propofol-fentanyl-ketamine (PFK) anesthesia for pediatric surgery was studied. Plasma levels of propofol (Pp) were maintained approximately at 2.5 micrograms.ml-1 during surgery. Fifteen minutes after the cessation of propofol infusion, Pp decreased to 1.5 micrograms.ml-1. Plasma levels of ketamine (Pk) were maintained at 150-200 ng.ml-1 during the surgery. After the cessation of ketamine infusion, Pk decreased as quickly as Pp. Pk values at 15 minutes and 120 minutes after the cessation of the infusion were 93 ng.ml-1, 24 ng.ml-1, respectively. On the other hand, plasma norketamine (Pn) levels increased gradually during surgery and stayed at 100-150 ng.ml-1 after the end of ketamine infusion to play an important role in post-operative sedation and pain relief. In conclusion, pharmacokinetics of propofol and ketamine in pediatric patients was similar to that in adult patients. PFK anesthesia can be used safely for pediatric as well as for adult patients.

[Clinical indication of propofol for pediatric patients--pharmacokinetics of propofol and ketamine during and after total intravenous anesthesia with propofol, fentanyl and ketamine (PFK) in a neonate]

A 60-day-old neonate boy received hepatic portojejunostomy for biliary atresia under PFK. Pharmacokinetics of propofol and ketamine during and after PFK was also studied. Plasma levels of propofol (Cp) and ketamine (Ck) were maintained at 2 to 3 micrograms ml-1 and at 200 to 300 ng ml-1 during surgery, respectively. Both Cp and Ck decreased quickly after the end of infusions. From the pharmacokinetic point of view, PFK may be safely applied even for neonates.

[Preanesthetic assessment of a patient with giant negative T waves on ECG following subarachnoid hemorrhage]

Giant negative T waves on ECG are associated with intracranial hemorrhage such as subarachnoid hemorrhage, ischemic heart disease such as subendocardial infarction, myocardial disease and others. They embarrass us in anesthetic management of urgent neurosurgical patients because of the requirement of making differential diagnosis among these diseases accompanying the ECG abnormality. An 80 year old woman undergoing radical clipping for cerebral artery aneurysm showed giant negative T waves on ECG. Although the ECG taken on admission to the hospital had been normal, huge giant negative T waves of 2 mV and QTc prolongation were detected on arrival in the operating room. Therefore, her cardiac function was evaluated by echocardiography to rule out subendocardial infarction. The echocardiogram revealed that wall motion of the left ventricle was mildly depressed, but her cardiac function was well maintained since the cardiac output was 4.1 l.min-1 and the ejection fraction was 59%. We thought that giant negative T waves were caused by subarachnoid hemorrhage and decided to perform anesthesia and surgery. Circulation during anesthesia and surgery was stable except a transient decrease in blood pressure due to massive hemorrhage during rupture of the aneurysm. We conclude that preanesthetic assessment of cardiac function by echocardiography is useful for anesthetic management of patients with giant negative T waves on ECG undergoing urgent radical operation for cerebral aneurysm.

In vivo spasmolytic effect of ketamine and adrenaline on histamine-induced airway constriction. Direct visualization method with a superfine fibreoptic bronchoscope

BACKGROUND

Ketamine (K) has been reported to produce bronchodilation in patients suffering from asthma. Although most researchers have used indirect measurements to study the effect of K in vivo, the reliability of these indirect methods are controversial. We have developed a new technique to measure the bronchial cross-sectional area (BCA) in vivo with a superfine fibreoptic bronchoscope (SFB). Employing this method, we evaluated in vivo spasmolytic effect of K and adrenaline (A).

METHODS

Twenty-one mongrel dogs were anaesthetized with pentobarbitone (30 mg.kg-1) and paralyzed with pancuronium (200 micrograms.kg-1.h-1). The trachea was intubated with an endotracheal tube that has a second lumen for insertion of a SFB (OD: 2.2 mm) to measure the BCA continuously. The tip of the SFB was placed between the 2nd and 3rd bronchial bifurcation of the right lung. A videoprinter printed the BCA, which was then measured with NIH Image. Bronchoconstriction was produced with histamine (H: 10 micrograms.kg-1 + 500 micrograms.kg-1.h-1) which was administered until the end of the experiment. The BCA was assessed before and 30 min after the start of H infusion. The dogs were randomly allocated to 3 groups of 7 dogs each. In group K, K (0-10 mg.kg-1) was given i.v., and the BCA was measured 5 min after each K dose. In group A, A (0-0.4 microgram.kg-1) was given i.v., and the BCA was measured 1 min after each A dose. In group A + K, K (1 mg.kg-1 i.v. + 1 mg.kg-1.h-1 i.v.) was given followed, 30 min after, by A i.v. in the same doses as in group A. The BCA was assessed 30 min after the start of K and again 1 min after each A dose.

RESULTS

K 10 mg.kg-1 reversed H-induced bronchoconstriction. A subthreshold dose of K significantly potentiated the effect of A, reversing the decrease in BCA by H.

CONCLUSION

We have found that K could reverse the H-induced bronchoconstriction and potentiate the A-induced bronchial relaxation.

[Perioperative management of a patient with cryoglobulinemia for open heart surgery]

A 57-year-old male with cryoglobulinemia underwent an aortic valve replacement for aortic regurgitation under total intravenous anesthesia with droperidol, fentanyl and ketamine in combination with mild hypothermic cardiopulmonary bypass (esophageal temperature = 34 degrees C). Preoperative steroid therapy with prednisolone of daily dose from 40 to 7.5 mg for six months and plasma exchange (3200 ml) on the day before the operation were performed to attenuate the degree of cryoglobulinemia. He showed an uneventful intraoperative course and there was no postoperative complication associated with cryoglobulinemia.

Haemodynamic and electroencephalograph responses to intubation during induction with propofol or propofol/fentanyl

PURPOSE

To observe the changes in EEG bispectral index (BIS), 95% spectral edge frequency (95% SEF) and median frequency (MF) with haemodynamic changes to intubation during induction with propofol or propofol and 2 micrograms.kg-1 fentanyl i.v.

METHODS

Twenty four ASA I-II patients were randomized to receive either propofol infusion preceded by normal saline (group P, n = 12) or propofol preceded by 2 micrograms.kg-1 fentanyl (group PF, n = 12). Intubation was performed five minutes after maintenance of BIS within 45 +/- 5. EEG and haemodynamic variables were recorded at before induction, and before and after intubation.

RESULTS

Haemodynamic responses to intubation were greater in group P than in group PF (P < 0.05). Postintubation SBP, DBP and HR increased, compared with preinduction values, more in group P than in group PF. Postintubation BIS values increased from 45.5 +/- 3.5 and 44.2 +/- 4.1 to 51.1 +/- 4.1 and 50.9 +/- 5.3 in groups P and PF, respectively, compared with preintubation values. The BIS values were not different between treatment groups before and after intubation, and 95% SEF and MF values did not increase after intubation.

CONCLUSION

Fentanyl, 2 micrograms.kg-1 i.v., blunted the haemodynamic responses to intubation, but failed to attenuate the arousal of cerebral cortical activity. The different haemodynamic responses postintubation but similar BIS and 95% SEF changes in the two groups suggest that BIS or 95% SEF cannot predict the haemodynamic responses to intubation during anaesthesia induction with propofol and fentanyl.

ONO-5046, an elastase inhibitor, attenuates liver mitochondrial dysfunction after endotoxin

OBJECTIVE

To investigate the effect of ONO-5046, an elastase inhibitor, on liver mitochondrial dysfunction after endotoxin administration.

DESIGN

Prospective, randomized, controlled animal study.

SETTING

Research laboratory.

SUBJECTS

Male Hartley guinea pigs.

INTERVENTIONS

Endotoxin shock was induced by intravenous infusion of Escherichia coli lipopolysaccharide endotoxin (50 mg/kg). Six guinea pigs were treated with endotoxin and saline. Twenty-four guinea pigs received 5, 10, and 30 mg/kg/hr of ONO-5046 after endotoxin administration. Six guinea pigs received only saline.

MEASUREMENTS AND MAIN RESULTS

We measured oxygen uptake in state 3 (substrate and adenosine 5'-diphosphate [ADP]) and state 4 (excess substrate, no ADP), as well as the respiratory control ratio (state 3/state 4), adenosine 5'-diphosphate/oxygen ratio (ADP/O), and arterial ketone body ratio. ONO-5046 was dose dependently effective in liver mitochondrial oxidative phosphorylation, such as oxygen uptake in stage 4, respiratory control ratio, adenosine triphosphate synthesis, ADP/O, and arterial ketone body ratio when ONO-5046 was started 30 mins after endotoxin. The administration of 30 mg/kg/hr of ONO-5046 improved mean blood pressure, which had decreased after endotoxin.

CONCLUSION

ONO-5046 attenuates the endotoxin-induced liver mitochondrial dysfunctions that may be related to increased liver blood flow.

Depressed pituitary-adrenal response to surgical stress in chronic schizophrenic patients

We evaluated whether pituitary-adrenal response to surgical stress is modified in chronic schizophrenic patients. Twenty-two schizophrenic patients on chronic antipsychotic therapy of phenothiazine derivatives over 10 years underwent orthopedic surgery of the extremities under general anesthesia by isoflurane and nitrous oxide. In chronic schizophrenic patients, responses of plasma epinephrine, norepinephrine, ACTH and cortisol levels during surgical stress were significantly lower than those of control patients. The attenuated response to surgical stress in these patients may be associated with their autonomic dysfunction and decreased pituitary-adrenal activity due to chronic administration of antipsychotic agents.

Midazolam reverses histamine-induced bronchoconstriction in dogs

PURPOSE

Midazolam has been used clinically as a sedative and as an anaesthetic induction agent. However, the bronchodilating effects of midazolam have not been comprehensively evaluated. We sought to determine relaxant effects of midazolam on the airway.

METHODS

After our Animal Care Committee approved the study, eight mongrel dogs were anaesthetized with 30 mg.kg-1 pentobarbitone iv, and were paralysed with 200 micrograms.kg-1.hr-1 pancuronium. The trachea was intubated with an endotracheal tube (ID 7 mm) that had a second lumen for insertion of a superfine fibreoptic bronchoscope (OD 2.2 mm) to measure the bronchial cross-sectional area (BCA) continuously. The tip of the bronchoscope was placed at the level of the second or third bronchial bifurcation of the right bronchus. A videoprinter printed the BCA which was then measured with a NIH image program. Bronchoconstriction was produced with histamine (H) 10 micrograms.kg-1 followed by 500 micrograms.kg-1.hr-1. Thirty minutes later, 0 [saline], 0.01, 0.1 and 1.0 mg.kg-1 midazolam and 25 micrograms.kg-1 flumazenil were given. The BCA was assessed before (basal area) and 30 min after the start of H infusion, and was also measured five minutes after each midazolam and flumazenil iv. At the same time, arterial blood was sampled for plasma catecholamine measurement.

RESULTS

Histamine infusion decreased BCA to 49.7 +/- 17.3% of basal BCA. More than 0.1 mg.kg-1 midazolam increased BCA up to 71.7 +/- 15.3% of the basal (1.0 mg.kg-1) (P < 0.01). Plasma adrenaline concentration was decreased from 6.9 +/- 3.8 to 3.7 +/- 1.9 ng.ml-1 by 1.0 mg.kg-1 midazolam (P < 0.05). Flumazenil did not antagonize the relaxant effect of midazolam but reversed the inhibitory effect of midazolam on histamine-induced adrenaline release.

CONCLUSION

Midazolam has a spasmolytic effect on constricted airways but this bronchodilatation was not reversed by flumazenil.

A rapid increase in foot tissue temperature predicts cardiovascular collapse during anaphylactic and anaphylactoid reactions

BACKGROUND

Cardiovascular collapse during anaphylactic and anaphylactoid reactions results from release of histamine and other vasoactive substances. Intense arteriolar vasodilation associated with severe allergic reactions is likely to increase convective transfer of heat and peripheral tissue temperature, and finally to provoke cardiovascular collapse. Therefore the authors tested the hypothesis that during anaphylactic and anaphylactoid reactions, an acute increase in peripheral tissue temperature precedes cardiovascular collapse and that the magnitude of the increase correlates with the severity of the reaction.

METHODS

During a 13-yr period, approximately 120,000 patients were screened for clinical evidence of intraoperative anaphylactic and anaphylactoid reactions. Core temperature was measured in the distal esophagus, and "deep" foot tissue temperature was measured on the sole of one foot in all these patients. Otherwise unexplained cardiovascular collapse accompanied by bronchospasm and/or cutaneous signs such as urticaria, flushing, or angioedema occurred in 32 patients who were entered into a prospective diagnostic protocol. Among these, 15 met laboratory criteria for anaphylactic or anaphylactoid reactions. Anaphylaxis was confirmed in nine of them by a positive skin test to the suspected agent, the in vitro leukocyte histamine-release test, or the Praunitz-Küstner test. Reactions were considered anaphylactoid in six others when laboratory evidence did not support anaphylaxis, but plasma histamine or tryptase concentrations were much greater during episodes than 6 weeks later.

RESULTS

Development of anaphylactic and anaphylactoid reactions followed a characteristic pattern: (1) Foot temperature, which was initially 3.3 +/- 1.7 degrees C less than core temperature, increased to within 0.3 degrees C of core temperature 3.2 +/- 1.4 min after drug administration; (2) onset of cardiovascular collapse ensued 1.8 +/- 0.8 min later; and (3) core temperature increased from 34.7 +/- 1.0 degrees C to peak values 37.1 +/- 0.6 degrees C 13 +/- 5 min after drug administration. The most severe reactions were associated with shorter times to comparable core and foot temperatures, faster onset of cardiovascular collapse, and higher maximum core temperatures.

CONCLUSIONS

The normal core-to-peripheral tissue temperature gradient was obliterated several minutes before hemodynamic consequences associated with anaphylactic and anaphylactoid reactions. Further, a rapid increase in deep foot temperature and maximum core temperature correlated with clinical severity.

[Changes in epidural pressure during total intravenous anesthesia with propofol, fentanyl and ketamine]

Although ketamine elevates cerebrospinal fluid pressure (CSFP) with an increase in cerebral blood flow, sedatives such as benzodiazepines, barbiturates and opioids have been reported to inhibit it. In this study, we evaluated the changes in epidural pressure (EP) as a good index for CSFP during total intravenous anesthesia with propofol-fentanyl-ketamine (PFK) compared to isofluranenitrous oxide anesthesia (GOI). Twelve patients for gastrectomy were allocated to two groups: PFK (n = 6) and GOI group (n = 6). In PFK group, epidural pressure did not increase during the anesthesia, and was significantly lower than in GOI group (30 and 180 min after induction of anesthesia, and 0, 30 and 60 min after stopping anesthetic administration). The present data suggest that PFK may safely be used for patients with intracranial hypertension.

Elimination of FK-506 by continuous hemodiafiltration in a liver transplant patient

A liver transplant patient who developed renal failure postoperatively was treated using continuous hemodiafiltration (CHDF). Doses ranging from 0.01 to 0.06 mg/kg/day of FK-506 had been administered intravenously. FK-506 concentrations before and after the filter, and in the ultradiafiltrate were 45.3 +/- 2.9, 56.0 +/- 5.3, and 9.1 +/- 3.1 ng/ml (mean, +/- S.D.), respectively. The filtration rate was 23.6 +/- 6.4%, and extracted FK-506 amounted to 522.0 micrograms (11.3% of administered dose). A part of the FK-506 administered was eliminated through the filter during CHDF.

[Preanesthetic meals in elective surgical patients]

This study investigated the effect of preanesthetic meals on the volume and pH of gastric contents in forty elective surgical patients ranging in ages from 20 to 60 years. Twenty patients who were given either isotonic beverage 250 ml or apple juice 250 ml on the morning of the operative day were subjected as control group and twenty patients of the breakfast group took two slices of bread with the above drink. About seven hours following drinking and feeding, the mean values of gastric volume were 20.9 +/- 18.3 ml in the control group and 19.2 +/- 16.3 ml in the breakfast group. The mean values of gastric pH were 4.3 +/- 2.3 in the drink group and 4.6 +/- 2.3 in the breakfast group. There were no significant differences in the gastric volume and pH between the two groups. However, very small amount of the bread was detected in the gastric fluid of three patients in the breakfast group. As preanesthetic drinking and feeding are advantageous for reducing the anxieties of preoperative patients and also for their nutrition during operation, it is encouraging that eating two slices of bread did not induce a significant effect of gastric volume or pH. The minute fragment of bread seems to have no clinically significant effect.

Measurement of bronchodilatation using a superfine fibreoptic bronchoscope

In this study, we report the development and accuracy of a direct technique to measure airway calibre using a superfine fibreoptic bronchoscope. Ten mongrel dogs were anaesthetized with pentobarbitone and the trachea intubated with a tracheal tube; the small lumen of the tube allowed passage of a superfine fibreoptic bronchoscope (od 2.2 mm). Bronchial cross-sectional area and airway pressure were recorded continuously and dynamic pulmonary compliance and airway resistance calculated. The dogs were allocated to one of two groups. In the first group (six dogs), bronchoconstriction was induced with histamine 10 micrograms kg-1 i.v. and 500 micrograms kg-1 h-1 c.i.v. Thirty minutes later, adrenaline 0-0.4 mg kg-1 was given i.v. Bronchial cross-sectional area, dynamic pulmonary compliance and airway resistance were assessed simultaneously. In the second group, 0.9% saline was given 30 min after placement of the superfine fibreoptic bronchoscope and 10 min later atropine 0.1 microgram kg-1 was administered. In the first group, histamine decreased mean percentage bronchial cross-sectional area by 49.2 (SD 11.5) %, reduced dynamic pulmonary compliance from 32.1 (12.6) to 22.3 (5.2) ml cm H2O-1 and increased airway resistance from 39.1 (11.6) to 57.2 (10.2) cm H2O litre-1 s-1. Adrenaline produced a dose-dependent increase in percentage bronchial cross-sectional area and dynamic pulmonary compliance to 119.4 (31.3)% and 27.4 (5.5) ml cm H2O-1, respectively, and a decrease in airway resistance to 43.9 (7.2) cm H2O litre-1 s-1. There were significant correlations between percentage bronchial cross-sectional area and dynamic pulmonary compliance (r = 0.720, P < 0.0001) and airway resistance (r = 0.727, P < 0.0001). Atropine 0.1 mg kg-1 increased basal bronchial cross-sectional area to 137.5 (16.9) %. These data indicate that adrenaline reversed histamine- and pentobarbitone-induced bronchoconstriction.

Ketamine relaxes airway smooth muscle contracted by endothelin

Endothelins (ETs) are synthesized not only in vascular endothelial cells but also in airway epithelial cells. Increased ET-1 has been demonstrated in bronchial epithelium of asthmatic patients, and, in severe asthma attacks, ET-1 increases in plasma and bronchoalveolar lavage fluid. In this study, we investigated whether ketamine (KET) relaxes ET-induced tracheal contractions. Female guinea pigs were killed with an overdose of pentobarbital. The trachea was removed and cut spirally into two strips that were mounted in an organ bath filled with Krebs-bicarbonate buffer. The response of each strip to 10(-7) M carbachol was taken as 100% contraction to which the response to ET was referred. The contribution of the epithelium to the relaxant effect of KET was studied in denuded tracheae or in the presence of 5 x 10(-5) M indomethacin. ET-1 (3 x 10(-8) M) induced contractions that were 76 +/- 3% of those induced by carbachol. KET reversed the response to ET-1 in a dose-dependent fashion. Similarly, ET-2 (3 x 10(-8) M) induced contractions that were 74 +/- 5% of those induced by carbachol, and KET also reversed this response in a dose-dependent manner. In epithelium-denuded strips, ET-1 induced contractions that were 104 +/- 3% of those induced by carbachol, and KET still reversed this response. The tonic phase of the response to ET-1 was equal (100 +/- 6%) to the response to carbachol, and KET did not affect it significantly. In the presence of ryanodine, KET reduced the ET-1-induced contraction from 67 +/- 2% to 36 +/- 3.%, P < 0.01. In the presence of nicardipine, KET also inhibited the ET-1-induced contraction. We conclude that KET relaxes the tracheal smooth muscle contracted by ETs via a mechanism that is independent of the tracheal epithelium. The relaxant effect of KET on the ET-induced contraction of the trachealis muscle is not dependent upon blockade of 1) sarcolemma influx of Ca2+ through the dihydropyridine Ca2+ channel or 2) the release of intracellular Ca2+ through the ryanodine-sensitive intracellular Ca2+ channel. It is likely that the action of KET relaxing ET-induced tracheal contractions is at some point of the inositol 1,4,5-trisphosphate signaling pathway.

[Therapeutic drug monitoring in perioperative period--management of atrial fibrillation in a patient with bradycardia due to relative overdose of digitalis]

We reported a 79 year old man with preoperative bradycardia due to relative overdose of digitalis prior to undergoing subtotal gastrectomy. The patient had received metildigoxin 0.2 mg.day-1 for atrial fibrillation preoperatively and severe bradycardia of 35-41 bpm was found on the preoperative ECG examination. Serum digoxin level was detected to be 1.91 ng.ml-1 on the day before surgery. We thought this serum level must be toxic for him, even though it was within normal limits for the majority. As we thought that his bradycardia had been caused by relative overdose of digitalis, he was withheld to receive metildigoxin on the day before surgery and thereafter. Heart rate on arrival at the operating theater was around 40-45 bpm, and therefore the patient was placed on a temporary pacemaker catheter before the anesthetic induction to prevent aggravating bradycardia during anesthesia and surgery. Heart rate during procedure was 50-70 bpm and hemodynamics was stable. Intravenous digoxin was restarted on the 2nd postoperative day because of decrease in serum digoxin level to 0.84 ng.ml-1 and it was converted to metildigoxin 0.1 mg.day-1 when he was permitted to take pills per os. Our experience demonstrates that perioperative therapeutic drug monitoring is clinically important for anesthesiologists to make proper pharmacological management of surgical patients who have received digitalis.

Increase in serum creatine phosphokinase concentrations after suxamethonium during sevoflurane or isoflurane anaesthesia in children

We have studied whether sevoflurane or isoflurane anaesthesia modulates the effect of suxamethonium on serum concentrations of enzyme markers of skeletal muscle function in paediatric patients. Eighty patients undergoing bilateral tonsillectomy, aged 5-12 yr, were allocated randomly to receive anaesthesia with either sevoflurane and nitrous oxide or isoflurane and nitrous oxide. Serum creatine phosphokinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) concentrations were measured before, and at 30 min and 20 h after induction of anaesthesia. Mean CK concentrations increased from 97.0 (SD 17.3) to 478 (170) iu litre-1 in the sevoflurane group and from 86.9 (22.4) to 628 (223) iu litre-1 in the isoflurane group, 20 h after induction of anaesthesia. Mean peak serum CK concentration in the sevoflurane group (478 (170) iu litre-1) was significantly less (P < 0.05) than that in the isoflurane group (628 (223) iu litre-1). Mean serum AST concentration increased from 17.5 (4.9) to 31.7 (3.5) iu litre-1 in the sevoflurane group and from 17.3 (2.4) to 34.8 (5.7) iu litre-1 in the isoflurane group, 20 h after induction of anaesthesia. Mean peak serum AST concentrations in the sevoflurane group were significantly lower (P < 0.05) than those in the isoflurane group. There were no significant differences in serum ALT or LDH concentrations between the groups either before or after anaesthesia. We conclude that administration of suxamethonium during either sevoflurane or isoflurane anaesthesia caused a marked increase in serum CK concentrations in paediatric patients. The clinical significance of this finding is uncertain.

The relaxant effect of ketamine on guinea pig airway smooth muscle is epithelium-independent

Airway epithelial cells and vascular endothelial cells modulate the tone of the underlying smooth muscle by releasing relaxing factors such as prostanoids and nitric oxide (NO). In the present study, we investigated whether the relaxant effect of ketamine depends on any of the epithelium-derived relaxing factors. Tracheae of female guinea pigs were cut spirally into strips (15 x 3 mm) and mounted in water-jacketed organ baths filled with Krebs-bicarbonate buffer aerated with a mixture of 95% O2 and 5% CO2 at 37 degrees C. Changes in the tension of the strips were measured isometrically with a force displacement transducer and recorded with a polygraph. In the first set of experiments, we examined the effect of ketamine on the concentration-response curves for histamine and carbachol in strips in which the epithelium was kept intact and in strips with denuded epithelium. In the second and third set of experiments, we studied the effect of indomethacin, a cyclooxygenase inhibitor, and N-omega-nitro-L-arginine methylester(L-NAME), a NO synthase inhibitor, on the relaxant activity of ketamine on tracheal strips contracted by histamine or carbachol. The following results were obtained: 1. Mechanical denudation of the tracheal epithelium shifted the concentration-response curve for histamine to the left (the 50% effective concentration [EC50] value of histamine decreased from 3.5 +/- 0.02 x 10(-6) M in the intact strips to 0.98 +/- 0.01 x 10(-6) M in denuded strips, P < 0.001). However, removal of the tracheal epithelium did not change the response to carbachol (the EC50 for carbachol was 1.1 +/- 0.02 x 10(-7) M in intact strips versus 0.88 +/- 0.01 x 10(-7) M after epithelial removal, P > 0.05). 2. Ketamine shifted to the right the concentration-response curves for histamine and carbachol in both intact and denuded tracheae. 3. Indomethacin did not alter the relaxant effect of ketamine on the tracheae contracted by either histamine (the concentration that inhibits 50% [IC50] of ketamine = 1.5 +/- 0.01 x 10(-3) M in control strips and 1.3 +/- 0.04 x 10(-3) M in strips pretreated with indomethacin, P > 0.05) or carbachol (the IC50 of ketamine was 2.5 +/- 0.02 x 10(-4) M in control strips and 2.4 +/- 0.01 x 10(-4) M in strips pretreated with indomethacin, P > 0.05). 4. L-NAME did not influence the relaxant effect of ketamine on tracheae contracted by either histamine (the IC50 of ketamine = 1.6 +/- 0.05 x 10(-3) M in control strips and 1.6 +/- 0.05 x 10(-3) M in strips pretreated with L-NAME, P > 0.05) or carbachol (the IC50 of ketamine = 2.6 +/- 0.04 x 10(-4) M in control strips and 2.3 +/- 0.01 x 10(-4) M in trips pretreated with L-NAME, P > 0.05). These results indicate that neither the mechanical removal of the tracheal epithelium nor the blockade of the release of potent mediators from tracheal epithelial cells influence the relaxant effect of ketamine on guinea pig tracheal strips contracted by histamine or carbachol. We conclude that ketamine relaxes the airway smooth muscle by an epithelium-independent mechanism.

Analgesic effect of a herbal medicine for treatment of primary dysmenorrhea--a double-blind study

We evaluated the analgesic effect of Toki-shakuyaku-san (TSS) in women who had a combination of "deficiency," of "Yin," "cold," and "stagnated blood" syndromes, and were suffering from dysmenorrhea. A diagnostic scoring system was used for determination of these conditions. We treated patients with either TSS or placebo during 2 menstrual cycles with a double-blind technique, and we followed them for 2 additional cycles. A significant alleviation of dysmenorrhea was observed in patients treated with TSS as compared to those treated with placebo. Our results suggest that TSS is effective for treatment of dysmenorrhea in patients with the above-mentioned conditions.

Uneventful total intravenous anaesthesia with ketamine for schizophrenic surgical patients

Ketamine has been considered to be contraindicated for schizophrenic patients because it may induce psychological emergence reactions and psychiatric deterioration. Total intravenous anaesthesia (TIVA) with ketamine combined with droperidol and fentanyl (DFK) has been used in 14 schizophrenic patients undergoing various surgical procedures. Two patients died post-operatively of concomitant severe disease rather than from schizophrenia related pathophysiology or anaesthetic complication. One patient showed transient mild anxiety in the early post-operative period soon relieved by the patient's routine medication. However, no patient developed exacerbations of psychosis or psychological emergence reactions during the first post-operative month. The cardiovascular state during and after DFK remained stable in all cases. It is concluded that ketamine when combined with droperidol and fentanyl is a satisfactory anaesthetic for patients with schizophrenia.

Possible Overestimation of Plasma Volume Determined by the Indocyanine Green Dilution Method in the Presence of Protein Leak From Capillary Beds – A Discussion of Two Clinical Cases

Indocyanine green (ICG) has been demonstrated to be a reliable indicator for the estimation of plasma volume in man. Since this dye is bound to plasma protein when administered intravenously, overestimation of the plasma volume would occur during the presence of protein leak from plasma. However, to our knowledge, up to now no report has described whether or not plasma volume determined by the indocyanine green dilution method (PV_ICG) is clinically significantly overestimated under such conditions. We report two burned patients who temporally had an unusual large PV_ICG even though other clinical variables did not support the presence of hypervolemia. From the case described it can be concluded that a possible overestimation of PV_ICG occurs when the vascular permeability for proteins is increased.

[A case of the foreign body due to "coring"]

A case of the foreign body due to coring from the rubbercap of a 50 ml Diprivan vial was reported. Furthermore, how the fragment is made and how to decrease the incidence are discussed. The incidence of coring should decrease by improvement of the needle and by sticking vials vertically. However, even if the improvement of the rubber, needles and sticking technique is achieved, the occurrence of coring can not be eliminated completely. The best way to avoid coring will be to furnish "50 ml syringes containing Diprivan" commercially.

Cortisol and catecholamine kinetics during continuous hemodiafiltration in patients with multiple organ dysfunction syndrome

OBJECTIVE

To assess the influence of continuous hemodiafiltration (CHDF) on cortisol and catecholamine kinetics in multiple organ dysfunction syndrome.

DESIGN

Consecutive clinical study.

SETTING

General intensive care unit of a university hospital.

PATIENTS

Ten adult patients with multiple organ dysfunction syndrome requiring CHDF.

MEASUREMENTS AND RESULTS

A total of 40 samples were collected during CHDF for cortisol and catecholamine assays. The clearances for cortisol, epinephrine, norepinephrine and dopamine were 2.5 +/- 1.7 ml/min, 26.3 +/- 2.7 ml/min, 16.7 +/- 4.2 ml/min and 26.3 +/- 2.6 ml/min (Mean +/_ SE), and their daily extractions were 1.8 +/- 0.2 mg/day, 11.4 +/- 4.8 micrograms/day, 1.0 +/- 0.1 micrograms and 2.3 +/- 0.3 micrograms/day, respectively. There were no significant changes in blood cortisol and catecholamine levels during CHDF conducted for 48 h.

CONCLUSIONS

The cortisol and catecholamine losses during CHDF were small and unlikely to lead to hemodynamic disturbances.

[Spread of Hanaoka's method of general anesthesia with Mafutsu-san: a discussion of surgical operations by Sanai Hashimoto]

It had been generally accepted that Hanoaka's secretiveness was the most contributory factor in preventing his method of general anesthesia with Mafutsusan from becoming wide spread in Japan. However, the author found several cases of the use of general anesthetic according to his method in various areas in Japan. For instance, Doryu Mikami, a surgeon of the Tsugaru feudal clan entered Hanaoka's school to study his medicine for several years and came back to Tsugaru to perform an amputation of the nose of a young lady with syphilis in about 1864. Hanaoka's method of general anesthesia was also practised safely in the Saga area of Kyushu even in the year of about 1900. The author studied in detail two cases of surgical operation under general anesthesia performed by Sanai Hashimoto, a physician of the Fukui feudal clan. One case was an amputation of the penis but no further detailed information was given to us. The other was an excision of the breast cancer of Toko Yoshida's wife. Yoshida was Hashimoto's teacher of Chinese literature. The operation was successful and the patient was reported to have survived three years after the operation. These facts strongly suggest that the method had been transmitted and practised in many districts in Japan by many disciples of his school. However, such cases have not been reported in detail. Thus the widely rumoured evaluation of Hanaoka's secretiveness is incorrect.