Measurement of coronary sinus flow using transesophageal echocardiography in patients undergoing coronary artery bypass grafting.

STUDY OBJECTIVE: To measure coronary sinus blood flow during coronary artery bypass graft (CABG) with transesophageal echocardiography (TEE). DESIGN: Prospective study. SETTING: Elective cardiac surgery at a university hospital. PATIENTS: Thirty-one ASA physical status III and IV adult patients free of significant coexisting disease and undergoing CABG. INTERVENTION: We measured coronary sinus blood flow velocity by using TEE and hemodynamic variables, before and after cardiopulmonary bypass (CPB) and after CPB. MEASUREMENTS AND MAIN RESULTS: We obtained a complete set of control measurements for 29 subjects (94%) and a complete set of post-CPB measurements in 28 patients (90%). In the normal group, peak velocity, and velocity time integral (VTI) of coronary sinus blood flow in the post-CPB period increased significantly compared with the pre-CPB period with CABG (n = 23). In the group of new regional wall motion abnormalities in the post-CPB period, peak velocity and VTI of coronary sinus blood flow in the post-CPB period did not increase significantly compared with the pre-CPB period by CABG (n = 5). CONCLUSIONS: We were able to measure the coronary sinus flow velocity by pulse-Doppler TEE during CABG. The peak velocity and VTI of coronary sinus blood flow in the post-CPB period increased significantly compared with in the pre-CPB period by CABG. The results of this preliminary study show the feasibility of clinical evaluation of CABG intraoperatively.

Sevoflurane exposure time and the neuromuscular blocking effect of vecuronium.

PURPOSE: To determine the effect of sevoflurane exposure time on the duration of vecuronium neuromuscular blockade. METHODS: In 40 adult patients anesthesia was induced with 1.5-2 mg x kg(-1) propofol and 3-5 microg x kg(-1) fentanyl and the trachea was intubated without the aid of muscle relaxant. Patients were randomized into four groups of 10. In group 1, 0.05 mg x kg(-1) vecuronium was administered with N2O and anesthesia was maintained by propofol infusion and fentanyl. Vecuronium was administered with sevoflurane 2% in 30 patients, commencing at the same time (group 2) and at 30, and 60 min after sevoflurane (groups 3, 4). Adductor pollicis force of contraction to train-of-four ulnar nerve stimulation was recorded. Times from vecuronium injection to 95%, maximal block, and recovery times to 25% recovery were recorded. RESULTS: There were no differences in times to 95% and maximal block in the four groups. Recovery times were longer in groups 3 and 4 than in groups 2 and 1 (P < 0.01). Times to 5% recovery were 15.0 +/- 3.7, 17.8 +/- 4.8, 28.2 +/- 9.9, and 29.5 +/- 9.5, and to 25% recovery were 22.3 +/- 5.2, 27.2 +/- 6.4, 42.3 +/- 16.3, and 50.5 +/- 16.4 in groups 1, 2, 3, and 4 respectively. No differences were found between group 1 and group 2 nor between group 3 and group 4. CONCLUSION: Sevoflurane produced time-dependent potentiation of vecuronium. After 30 min exposure, 25% recovery was prolonged by 89% and after 60 min by more than 100% compared with the control group.

A new approach for brachial plexus block under fluoroscopic guidance.

UNLABELLED: We performed the subclavian perivascular approach to the brachial plexus using contrast medium to confirm the location of the tip of the needle and the spread of the injected solution to obtain a high success rate and to minimize the risk of pneumothorax. Review of the cases led to the hypothesis that the solution injected inside the costal attachment of the middle scalene muscle spreads into the interscalene space. Because of the difference in the placement of the tip of the needle using our technique and the supraclavicular approach, including the subclavian perivascular approach, we termed our technique the supracostal approach. We conducted the present study to establish the supracostal approach by proving this hypothesis. A total of 173 blocks in 149 adult patients were studied. Eighty-four blocks in 74 patients were achieved by using the supracostal approach with contrast medium. The needle was inserted 1 cm lateral to the palpated subclavian artery and 1-2 cm above to the clavicle to touch a specific part of the first rib, which we believed to correspond to the inside of the costal attachment of the middle scalene muscle. After injecting the anesthetic solution with contrast medium, radiographs were obtained for each block, while computed tomographic (CT) studies were performed for five blocks. Five blocks in five patients were achieved by using the subclavian perivascular approach with contrast medium and both radiographs and CT studies. In addition, the anatomical difference between the two approaches was evaluated in five adult cadavers. Based on these studies, we determined the proper part of the first rib that corresponded to the inside of the costal attachment of the middle scalene muscle. Eighty-four blocks in the remaining 70 patients were performed with the supracostal approach without contrast medium. Of the 84 blocks with contrast medium, 80 (95%) produced successful blockade defined by sensory and motor examination. The radiological studies showed that, with the supracostal approach, the injected solution, which spread from the middle scalene muscle into the interscalene space, did not spread below the first rib. However, with the subclavian perivascular approach, the solution was confined within the perineural sheath and spread below the first rib to the axilla. The anatomical studies could explain this difference, revealing that the perineural space of the brachial plexus is not identical to the interscalene space. There was no failure in the 84 blocks performed with the supracostal approach without contrast medium after we determined the proper part of the first rib. We conclude that the supracostal approach to the brachial plexus is reliable, easy to perform, and associated with a low complication rate. IMPLICATIONS: A new fluoroscopically guided approach for brachial plexus block has been established on the basis of anatomical and radiological studies to be reliable, easy to perform, and associated with a low complication rate.

Role of wall tension in hypoxic responses of isolated rat pulmonary arteries.

The changes in force developed during 40-min exposures to hypoxia (37 +/- 1 mmHg) were recorded in large (0.84 +/- 0.02-mm-diameter) and small (0.39 +/- 0.01-mm-diameter) intrapulmonary arteries during combinations of mechanical wall stretch tensions (passive + active myogenic components), equivalent to transmural vascular pressures of 5, 15, 30, 50, and 100 mmHg, and active (vasoconstriction) tensions, stimulated by PGF2alpha in doses of 0, 25, 50, and 75% effective concentrations. Constriction was observed in all arteries during the first minute; however, at any active tension, the pattern of the subsequent response was a function of the stretch tension. At 5, 15, and 30 mmHg, the constriction decreased slightly at 5 min and then increased again to remain constrictor throughout. At 50 and 100 mmHg, the initial constriction was followed by persistent dilation. Hypoxic constrictor responses, most resembling those observed in lungs in vivo and in vitro, were observed when the mechanical stretch wall tension was equivalent to 15 or 30 mmHg and the dose of PGF2alpha was 25 or 50% effective concentration. These observations reconcile many apparently contradictory results reported previously.

[Propofol anesthesia for a patient with insulinoma].

We experienced the anesthetic management of a 47-year-old woman with insulinoma. Removal of the tumor was performed under propofol, nitrous oxide, and epidural anesthesia. We tried the continuous infusion of glucose to maintain normal blood glucose level and to avoid intraoperative hypoglycemic event. The blood glucose and immunoreactive insulin (IRI) level were measured intermittently. After the removal of the insulinoma, the IRI level decreased rapidly to the normal range. In this case, neither hyperglycemic nor hypoglycemic episode was observed. The perioperative course was uneventful. Propofol has not been shown to significantly affect the release of insulin and glucose regulation. This case suggests that under the condition of continuous glucose infusion and blood glucose monitoring, propofol is an useful anesthetic agent for a patient with insulinoma.

Hemodynamic evaluation of the prone position by transesophageal echocardiography.

STUDY OBJECTIVE: To evaluate the hemodynamic response in the prone position in surgical patients by measuring the effects of prone positioning on cardiac function using transesophageal echocardiography (TEE). DESIGN: Prospective study. SETTING: Elective surgery at a university hospital. PATIENTS: 15 adult ASA physical status I and II patients free of significant coexisting disease undergoing lumbar laminectomy. INTERVENTIONS AND MEASUREMENTS: Approximately 15 minutes after the induction of general anesthesia, we measured heart rate, blood pressure, and central venous pressure. We also measured left ventricular area (LVA) and fractional area change (FAC) automatically and calculated left ventricular volume (LVV), stroke volume index (SVI), cardiac index (CI), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), pulmonary venous flow velocity (PVFV), and pulmonary venous velocity time integral (PVVTI) via TEE. The same measurements were performed approximately 15 minutes after changing to the prone position with longitudinal bolsters. MAIN RESULTS: In the prone position, there was significant reduction in end-systolic and end-diastolic LVA and LVV. There was a significant increase in LVEF, LVFS, and FAC in the prone position. In addition, there was diminishment of systolic PVFV and PVVTI and enhancement of diastolic PVFV and PVVTI. SVI and CI did not change significantly in the prone position. CONCLUSION: The prone position caused LVV to decrease. The prone position also led to decreased systolic PVFV and PVVTI and enhancement of diastolic PVFV and PVVTI. These changes were probably due to a decrease in the venous return due to inferior vena caval compression, and decreased left ventricular compliance due to increased intrathoracic pressure in the prone position.

[The problems of Japanese home care for cancer pain patients].

Terminal stage was informed to the incurable cancer patient, suffering severe pain and riding wheel chair in the hospital. Whether her therapy had been continued in the hospital or in her house has been discussed several times with patient her self or her family. We decided to continue her final therapy in her house, however we had to give up the therapy in her house because of so many problems. These experience taught us that house health care system may produces so many unsolved problems in Japan.

Effect of anaesthetic agents on the phagocytic function of human polymorphonuclear leukocytes through analysis with a phagocytic plaque method.

We examined the effects of the intravenous anaesthetic agents, thiamylal and ketamine, on the phagocytic function of polymorphonuclear leukocytes (PMN) in heparinized peripheral blood from healthy individuals using the phagocytic plaque method. Subclinical doses of thiamylal caused enhancement of the phagocytic activity of PMN and super-clinical doses of thiamylal inhibited phagocytic activity of PMN. Ketamine did not adversely affect phagocytic function at relevant therapeutic concentrations. The results presented in this manuscript indicate the phagocytic plaque method can provide a quantitative assessment of the phagocytic function of leukocytes. This method may prove useful in determining whether anaesthetic agents and other drugs adversely affect leukocyte function and hence help prevent the increased susceptibility to infection which can occur in anaesthetized patients. Conversely, the phagocytic plaque method may prove useful in the search for immune-enhancing drugs.

[A comparison between neuromuscular blocking effects of pipecuronium and vecuronium; a double blind controlled study in collaboration with 5 departments of anesthesiology].

Neuromuscular blocking effects of pipecuronium bromide 0.04 mg.kg-1 were compared those of vecuronium bromide 0.08 mg.kg-1 in a double blind study. Fifty surgical patients (ASA I or II) were allocated randomly to two groups of each 25 cases and they were anesthetized with nitrous oxide 4 l.min-1, oxygen 2 l.min-1 and isoflurane 1 MAC. Neuromuscular blockade was monitored by using mechanical twitch responses of the thumb to electrical stimulations of the ulnar nerve. Adequate neuromuscular relaxation for surgery of 85.8% to 100% block was obtained by this dose of pipecuronium. The duration of action and recovery time from 75% to 25% block were longer than those produced by twice the dosage of vecuronium (62.3 +/- 37.15 vs. 40.4 +/- 16.09 min, and 48.1 +/- 22.0 vs. 19.9 +/- 10.8 min, P < 0.05). The blocks by both drugs responded to neostigmine. Cardiovascular side effects of the both agents were not found. From these results, it is concluded that pipecuronium is a useful nondepolarizing relaxant with a long duration of action and negligible side effects.

[Differential reactivities of three kinds of carbon dioxide absorbents with sevoflurane].

The differential reactivities of three kinds of carbon dioxide absorbents, Soda lime, Soda lime A, and Baralyme with sevoflurane were investigated. Sevoflurane was made to react with each carbon dioxide absorbents in a glass vial or in a closed system under administration of carbon dioxide. Glass vials were kept at 55 degrees C and 70 degrees C, and three kinds of carbon dioxide absorbents were compared regarding their reactivity under each temperature. In a closed system, we also monitored the temperature of glass container which was filled with each carbon dioxide absorbent. In a glass vial, the highest reactivity of sevoflurane was found with Baralyme. Although Soda lime A decomposed sevoflurane less than Baralyme or Soda lime in glass vial, the highest reactivity of sevoflurane in a closed system was found with Soda lime A. On the other hand, Soda lime A increased the temperature of glass container most. As increasing temperature tends to promote reaction, the possibility that the high temperature of the glass container contributes to the reactivity of sevoflurane with carbon dioxide absorbents exists. These results suggest that the highest reactivity of Soda lime A with sevoflurane was caused by the highest temperature of glass container although its chemical composition makes it most reactive with sevoflurane than the others.

Role of cysteine residues in esterase from Bacillus stearothermophilus and increasing its thermostability by the replacement of cysteines.

Bacillus stearothermophilus esterase contains two free cysteine residues at positions of 45 and 115, which react with sulfhydryl reagents resulting in a significant decrease in the enzymatic activity. To understand the role of the cysteine residues in catalytic regions of the esterase, the residues were replaced with serine or alanine by site-directed mutagenesis to construct four single-mutated enzymes (C45A, C45S, C115A, C115S) and two double-mutated ones (C45/115A and C45/115S). Wild-type and mutant enzymes were produced in Escherichia coli cells and purified to homogeneity to examine their chemical and kinetic properties. These mutant enzymes had esterase activity, which suggested that none of the cysteines were required for its activity. Moreover, replacement of both two-cysteine residues made the enzyme insensitive to p-chloromercuribenzoic acid and extensively stabilized it at high temperatures of around 70 degrees C. These results demonstrate that replacement of free cysteine residues by site-directed mutagenesis can improve the thermostability of thermophilic enzymes.

[Evaluation of pipecuronium bromide during halothane or enflurane anesthesia--a comparison with pancuronium regarding the optimal dose and the effect of volatile anesthetics on neuromuscular blockade].

Pipecuronium, a new muscle relaxant, was examined in surgical patients in a multi-center cooperative study. Neuromuscular blocking action, circulatory effect and side effects of pipecuronium were investigated in comparison with those of pancuronium bromide. Mechanical twitch responses of adductor pollicis muscle evoked by supramaximal stimulation of the ulnar nerve every ten seconds were recorded. The following results were obtained. 1. Approximately 100% twitch depression was obtained after the administration of pipecuronium 0.04 mg.kg-1. 2. Enflurane and halothane did not influence the onset time and recovery time. But enflurane showed more prolonging effect on the duration of pipecuronium induced block than halothane. 3. No clinically significant changes in heart rate and blood pressure were observed. It was concluded that the minimum of 0.04 mg.kg-1 of pipecuronium is necessary for an initial dose and the maintenance dose of pipecuronium can be reduced under enflurane anesthesia.

[A 5-year-old patient with allergic diseases responsive to stellate ganglion block].

We examined a 5-year-old boy with allergic rhinitis, chronic sinusitis, atopic dermatitis, and tendency to suffer common cold, who responded to stellate ganglion block (SGB). SGB therapy was extremely effective for this patient. The result suggests that SGB therapy should be performed on patients with allergic diseases resistant to drug and diet therapy. Furthermore, the indication for nerve block therapy, such as SGB, may be extended even to pediatric patients.