Showing papers in "Masui. The Japanese journal of anesthesiology in 1990"

Plasma catecholamine response to tracheal intubation after midazolam and vecuronium in elderly patients with hypertension

Abstract: This study was undertaken to determine whether midazolam alleviates sympathoadrenal response evoked by tracheal intubation in elderly patients with hypertension. Anesthesia was induced with midazolam in a sleep dose followed by vecuronium 0.1 mg.kg-1. Heart rate and blood pressure were recorded before, 1 and 3 minutes after induction with intubation. Free and total catecholamine (CA) in plasma were measured at each time. Dopamine, norepinephrine and epinephrine (EN) were determined using fluorescence derivatization with diphenylethylenediamine by HPLC. Although heart rate and diastolic pressure rose in some degree 1 min after intubation, free and total CA concentrations did not increase during study period. Free and total EN levels decreased significantly 3 min after intubation. The absence of elevation in plasma CA concentrations, especially in free CA, which is physiologically active, would contribute to produce circulatory stability on laryngoscopy and tracheal intubation. However, the mystery of why hyperdynamic state was produced without the increase in CA concentrations remains to be solved, even though it occurred for a short period of time.

Antibacterial activity of local anesthetics

Abstract: In order to study the antibacterial activity of local anesthetics quantitatively, we procured their minimum inhibitory concentration (MIC), killing curves and postantibiotic effect (PAE), using the standard colony of Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 14990 and Pseudomonas aeruginosa NCTC 10490. Both bupivacaine and lidocaine had bactericidal activity at a clinical concentration. MIC of the former was lower than that of the latter, and it means that bupivacaine has a greater antibacterial activity than lidocaine. At the same concentration, the commercial solutions, such as Xylocaine and Marcain, which contain preservatives, showed a greater antibacterial activity than the pure anesthetic solutions which contain no preservatives. However, the preservatives had no bactericidal activity, but weak bacteriostatic activity.

[Macroglossia after neck clipping of a VA-PICA (vertebral artery-posterior inferior cerebellar artery) aneurysm].

Abstract: A case of macroglossia following neck clipping of VA-PICA aneurysm is described. The etiology of this rare complication has been thought to be venous obstruction related to extreme flexion of the head in the sitting position. On the other hand, Moore et al recently proposed that the primary mechanism of macroglossia after posterior fossa exploration might be neurogenic origin. We consider that our case supports the latter hypothesis. In our case, the lingual swelling was aggravated for four consecutive days following the operation and then began to improve rapidly. The swelling resolved completely after 4 weeks. Glyceol and methylprednisolone sodium succinate were administered in an attempt to decrease the lingual swelling. But these drugs did not effectively minimize the swelling. It seemed that the lingual swelling resolved spontaneously. If macroglossia following posterior fossa exploration can be caused by abnormal autonomic nervous system discharges, stellate ganglion block, glossopharyngeal nerve block or vagus nerve block is thought to be indicated as treatment for the lingual swelling.

Effects of intratracheal lidocaine spray on circulatory responses to endotracheal intubation

Abstract: The effect of intratracheal lidocaine spray (0.5, 1.0, 2.0 mg.kg-1) on blood pressure and heart rate changes to endotracheal intubation was evaluated in 20 ASA I-II patients. After thiamylal induction, 15 patients received lidocaine spray with LTA kit. Mean arterial blood pressure and heart rate were recorded for 10 min every 30 sec and analysis of plasma lidocaine concentrations were also performed. In the control group, mean arterial blood pressure increased significantly compared with the pre-anesthetic values for one min, and with all spray groups at one min after intubation. Heart rate increased significantly at 30 sec after intubation only in the control group. Since the plasma lidocaine concentrations at intubation were below 1.5 micrograms.ml-1, we conclude that intratracheal lidocaine spray depresses the circulatory response to intubation by its local surface analgesic effect.

[Skin disinfectants for nerve blocks and their long-lasting antimicrobial effects].

Abstract: Although epidural catheterization has many advantages in anesthesia and in the treatment of acute pain, spinal epidural abscess is a serious complication after the procedure. Since it is presumed that the epidural space is contaminated by bacteria on the skin via the space around the catheter, it seems important to clarify bacterial re-growth after application of skin disinfectant. Therefore, bacterial growths on human back 1, 2 days, and 1 week after application of disinfectants were studied in summer and winter to elucidate whether there are differences between the two seasons. Four disinfectants, 0.5% chlorhexidine in 80% ethyl alcohol (CA), 0.2% benzalkonium in 80% ethyl alcohol (BA), 10% povidone iodine (PI), and 80% ethyl alcohol (EA) were applied on the back of 76 adult healthy volunteers, and the specimens were taken by agar-contact method. The frequencies of positive cultures for bacteria were higher in summer than in winter. The frequencies of positive culture in summer after the applications of CA, BA, PI, and EA were as follows, respectively: 50%, 20%, 5%, and 40% after 1 day; 47%, 50%, 60%, and 50% after 2 days; and 82%, 82%, 70%, and 64% after 1 week. In winter, these frequencies after the application of CA, BA, PI, and EA were as follows, respectively: 0%, 0%, 18%, and 18% after 1 day; 5%, 26%, 32%, and 58% after 2 days; and 21%, 21%, 32%, and 42% after 1 week. We conclude that when an epidural catheter is in situ, more frequent skin disinfection has to be carried out, preferably by CA, in summer than in winter, since the presence of sweat on the back seems to hasten the re-growth of bacteria.

Reaction products of sevoflurane with components of sodalime under various conditions

Abstract: Sevoflurane is reported to react with sodalime to resolve into several products. We examined the reaction products of sevoflurane when this anesthetic reacted with components of sodalime under various conditions. Analysis of reaction products was performed by gas chromatography using a 2m column packed with DOP. Six peaks including sevoflurane were detected on the gas chromatogram of sevoflurane after reaction with sodalime and five reaction products were obtained. These peaks were from P1 with the shortest retention time to P5 with the longest retention time. When sevoflurane was sealed with sodalime in a test tube at room temperature, only P1 was detected and all reaction products of P1 to P5 were identified when the test tube was heated at 50 degree C for 3 hours. Sodalime contains Ca (OH)2, NaOH, KOH and silicon dioxide. Reaction of sevoflurane with KOH produced P1 to P5 products even at room temperature. After the reaction of sevoflurane with NaOH or Ca (OH)2 at 50 degrees C, P1 to P5 or P1 only were detected on the chromatogram respectively. No peak of any reaction products was obtained after the reaction with silicon dioxide under various conditions. These results suggest that hydroxy group of sodalime component would increase reaction products of sevoflurane.

A case report of postoperative thyroid crisis accompanied with struma ovarii

Abstract: A 39-year-old female without any specific past history was scheduled to receive an operation for myoma uteri and ovarian cyst. She was premedicated with atropine. Anesthesia was induced with thiopental and was maintained with nitrous oxide and enflurane. Tachycardia shortly after premedication with atropine and remarkable sweat during the operation were observed. On the 1st postoperative day an outbreak of thyroid crisis as well tachycardia of 180.min-1 and fever (39.3 degrees C) were observed. Such outbreak of thyroid crisis indicated that the patient had been suffering from Grave disease. Pathological diagnosis of extirpated ovarian cyst was struma ovarii. It is, however, still uncertain whether struma ovarii induced thyroid crisis in this case. It might be concluded that screening of hyperthyroidism at preoperative rounds is essential for prevention of thyroid crisis.

Anesthetic management of a patient with a giant ovarian tumor complicated with cerebral palsy

Abstract: The anesthetic management of a patient with a giant ovarian tumor (16.5kg) was reported. The patient was a 32 year old female with cerebral palsy and severe mental retardation. The management of anesthesia in this case including induction of anesthesia, intra-operative hypotension due to removal of tumor and post operative pulmonary complication, should be considered carefully. Especially, the monitoring of central venous pressure was essential, because the venous return fluctuates markedly depending on the surgical procedure. Patient had no premedication. Anesthesia was induced with halothane, nitrous oxide and oxygen by mask with the monitoring of ECG, and radial arterial as well as central venous pressure. Following easy tracheal intubation, bronchospasm occurred, which induced multifocal PVC's. This PVC turned to bigeminy and treatment with such drug as lidocaine was not effective. Anesthesia was maintained with enflurane, nitrous oxide and oxygen. Bigeminy disappeared 5 minutes after discontinuing enflurane anesthesia. Post-operative course was uneventful. The merit of slow induction method with halothane, nitrous oxide and oxygen has not been proved in this special case.

[Intraoperative coronary artery spasm--retrospective review of 10 cases]

Abstract: Ten cases of intraoperative coronary artery spasm were reviewed retrospectively. Four cases were open heart surgeries, one was a surgery for aortic dissecting aneurysm, and the other five were abdominal ones. In the cases of open heart surgery under anesthesia with high dose fentanyl, coronary artery spasm occurred at weaning period from cardio-pulmonary bypass. In the cases of abdominal surgery, all under neuroleptanesthesia with continuous epidural block, coronary artery spasm occurred within one hour after the beginning or before the end of operation. In four of five abdominal surgeries, systolic blood pressure became less than 90 mmHg when coronary artery spasm occurred. Coronary artery spasm brought severe depression of myocardial contractility and life threatening arrhythmias by which weaning from cardiopulmonary bypass became difficult during open heart surgery. There was a case which required several hours before hemodynamics became stable also in abdominal surgery. It was suggested that general anesthesia with continuous epidural block could be a triggering factor of coronary artery spasm when hypotension and insufficient depth of general anesthesia are present simultaneously.

Effects of dopamine and dobutamine on hepatic circulation and metabolism in hemorrhagic hypotensive pigs

Abstract: Effects of dopamine and dobutamine in a dose of 5, 10 or 20 micrograms.kg-1.min-1 on hepatic blood flow and hepatic metabolism were studied in normotensive and hemorrhagic hypotensive (MAP 50mmHg) pigs during 1 MAC enflurane anesthesia. PaCO2 was maintained within a physiological range (30-35mmHg) by controlled ventilation. Portal venous blood flow and hepatic arterial blood flow were measured by ultrasonic blood flowmetry. Hepatic oxygen supply and consumption were calculated from blood flows and oxygen contents. Each dose of dopamine and dobutamine did not change significantly MAP and cardiac output in both normotensive and hypotensive pigs. In the normotensive state, dopamine increased significantly total hepatic blood flow and hepatic oxygen supply, by raising portal venous blood flow, but dobutamine did not increase them. Also in the hemorrhagic hypotensive state, dopamine increased significantly total hepatic blood flow and hepatic oxygen supply by increasing both portal venous blood flow and hepatic arterial blood flow, but dobutamine did not produce similar increase. On the other hand, there was no significant change in hepatic oxygen consumption in both normotensive and hypotensive pigs by dopamine and dobutamine administration. These results suggest that dopamine is superior to dobutamine for hepatic circulation and hepatic metabolism especially in the hemorrhagic hypotensive state.

Ketamine infusion for control of pain in patients with advanced cancer

Abstract: The effect of ketamine infusion to control the intractable pain which had not responded to ordinary procedures in 12 patients with advanced cancer were evaluated. Ketamine 250 mg or 500 mg in 500 ml of transfusion fluid with or without 10 to 20 mg of droperidol was administered intravenously at the rate of 3 to 20mg of ketamine per hour. The pain scores by VAS in most of the patients decreased significantly with an averaged value of 8.3 before the treatment to 1 during the procedure. The durations of this therapy lasted from over 6 hours to 48 days. Slight disorientation in one patient and drowsiness in 5 were seen during the infusion. No cardiovascular or respiratory complications were noted. These results indicate that ketamine infusion is a useful therapeutic procedure to treat cancer pain which resist ordinary pain therapies.

[Reaction products of sevoflurane with new soda lime-A under various conditions].

Abstract: Sevoflurane is reported to react with sodalime, a common carbon dioxide absorber which resolves into several products. We measured the reaction products of sevoflurane when this anesthetic reacted with sodalime-A, a new carbon dioxide absorber under various conditions. Analysis of reaction products was done by gas chromatography using a 2 m column packed with DOP. Six peaks including sevoflurane were detected on the gas chromatogram of sevoflurane after reaction with sodalime-A and five reaction products were obtained. These peaks were from P1 with the shortest retention time to P5 with the longest retention time. When sevoflurane was sealed with sodalime-A in a test tube at room temperature, 40 degrees C and 45 degrees C, only P1 was detected and two reaction products of P3 and P5 were identified when the test tube was heated at 50 degrees C. Sodalime contains Ca(OH)2, NaOH, KOH and silicon dioxide, and sodalime-A contains Ca(OH)2 and NaOH only. We reported previously that sevoflurane reacted with KOH to produce P1 to P5 even at room temperature and KOH was the most contributing factor to produce these reaction compounds. Reaction products of sevoflurane with two types of carbon dioxide absorber were checked with gas chromatography. Degradation products except P1 with sodalime-A was less than with conventional sodalime at any conditions. P1 production was about twice to three times more than that with sodalime.

Anesthetic management of a patient with osteogenesis imperfecta congenita

Abstract: We experienced anesthetic management of three cases of osteogenesis imperfecta. Case 1: A 2-year-old boy weighing 8.6 kg was premedicated with chloral hydrate 250 mg intrarectally, but he was very excited on arrival at the operating room. Induction of anesthesia was performed by intramuscular injection of ketamine 40 mg. Case 2: A 4-year-old girl underwent three surgeries (2 osteomies and 1 intramedullary nailing of the tibias) during the past two years. On the second and third procedures, marked hyperthermia (over 39.2 degrees C as rectal temperature) developed during halothane (1-2%) and enflurane (1.5-2.5%) anesthesia. However, on the first surgery, hyperthermia did not occur under combined light halothane (0.3-0.5%) anesthesia with caudal epidural block. Case 3: A 14-year-old female underwent osteotomy of the radius under brachial plexus block without any anesthetic complications. In conclusion, anesthetic considerations for children with this disease are as follows; 1) It is necessary to premedicate to provide good preoperative sedation. 2) Care should be taken to use inhaled anesthetic agents (halothane and enflurane) because of tendency to develop abnormal hyperthermia. 3) It is desirable to use regional anesthesia.

Endocrine effects of hypotension induced by nicardipine in rabbits

Abstract: Endocrine effects of hypotension induced by nicardipine, a calcium antagonist, were studied in 18 male rabbits under halothane anesthesia. They were randomly divided into two groups; nicardipine (group N; n = 10) and controls (group C; n = 8). No change was noted in plasma catecholamines in group C throughout the experiment, but plasma renin activity decreased progressively. During and after induced hypotension, in group N, plasma epinephrine was significantly higher than the control value. The highest level of plasma epinephrine was seven times of the control value during 30 minutes after induction of hypotension. Plasma norepinephrine of group N was significantly higher than the controls. The maximum increase occurred 60 minutes after induction of hypotension. Plasma renin activity of group N was significantly higher than the control value. Compared with the control value (15.1 +/- 1.8 ng.ml-1.hr-1), plasma renin activity was activated 30 and 60 minutes after induction of hypotension (55.5 +/- 6.0 ng.ml-1.hr-1, P less than 0.001, 50.3 +/- 7.1 ng.ml-1.hr-1, P less than 0.01, respectively). In conclusion, our data show that hypotension by nicardipine activates the renin-angiotensin-sympathetic system.

[Plasma cortisol levels during abdominal surgery under sevoflurane anesthesia: comparison between gastrointestinal and gynecological surgery].

Abstract: Plasma cortisol levels during abdominal surgery under sevoflurane anesthesia were evaluated in 22 patients who ranged in ages from 37 to 65. They underwent either gastrointestinal or gynecological abdominal surgery. Anesthesia was induced and maintained with sevoflurane (1-5%) in nitrous oxide (4 l.min-1) and oxygen (2 l.min-1). Succinylcholine was administered intravenously to facilitate tracheal intubation and pancuronium was given intravenously during surgery. Lactated Ringer's solution at a speed of 10-15 ml.kg-1.hr-1 was also administered intravenously throughout the surgical procedures. Plasma cortisol levels were unchanged with the induction of sevoflurane anesthesia alone, but they increased significantly 2-3 times of the preanesthetic levels during and after surgery in both groups. However, the concentrations of plasma cortisol after recovery from anesthesia were significantly higher in the gastrointestinal group than in the gynecological group. The findings suggest that plasma cortisol levels after surgery reflect the difference in magnitude of stress response between gastrointestinal and gynecological surgery.

Cardiovascular effects of apnea test in the diagnosis of brain death

Abstract: Cardiovascular effects of apnea test were investigated in 12 patients suspected of brain death. Arterial blood gas and cardiovascular hemodynamics were measured just before and after 10-minute apnea. Apnea test induced respiratory acidosis without hypoxemia. Cardiac index increased by 34% (2.3 to 3.1 l.min-1.m-2; P less than 0.01) and systemic vascular resistance index decreased by 30% (3608 to 2519 dynes.sec.cm-5.m-2; P less than 0.01), whereas heart rate and mean arterial pressure were unchanged. Significant increases in mean pulmonary arterial pressure (17.6 to 29.1 mmHg; P less than 0.01), pulmonary vascular resistance index (381 to 616 dynes.sec.cm-5.m-2; P less than 0.01) and right ventricular stroke work index (4.0 to 10.5 g.m.m-2; P less than 0.01) suggest that apnea test increases right ventricular afterload.

Anesthesia for a patient with spinocerebellar degeneration who developed atrioventricular block

Abstract: A 54-year-old female with a history of spinocerebellar degeneration (SCD) and myoma uteri had general anesthesia for the abdominal total hysterectomy. Though the operation was uneventfully performed, various atrioventricular blocks occurred. These might be related to the SCD. Hypertonic state of the vagus was considered to be the quite possible cause of the block. Myocardial degeneration associated with the SCD was also an undeniable factor of the block. No arrhythmia occurred and symptoms of the SCD were not aggravative after the anesthesia and the patient was discharged uneventfully.

Hemodynamic features of hypotension induced by nicardipine in dogs

Abstract: Hemodynamic features of hypotension induced by nicardipine were studied in 18 mongrel dogs under 0.87% halothane in oxygen (1MAC). They were randomly allocated to one of two groups. Group C received no vasodilator therapy and served as control and group N received infusion of nicardipine. Mean arterial pressure decreased and was maintained at 60 mmHg for 60 minutes in group N. No change was noted in hemodynamic variables measured in group C throughout the experiment. During and after induced hypotension in group N, cardiac index (CI), stroke volume index (SVI), central venous pressure (CVP), and right ventricular stroke work index (RVSWI) increased significantly compared with the control values. On the other hand, systemic vascular resistance (SVR) was significantly reduced, reaching 25% of the control value at the end of hypotension period. Heart rate showed a progressive increase but not significantly. Left ventricular maximum dp/dt showed a moderate increase during hypotension, but then decreased gradually to the control value after induced hypotension. Left ventricular stroke work index (LVSWI) and pulmonary vascular resistant (PVR) were unchanged from the control value during and after induced hypotension. The data indicate that nicardipine is a potent systemic vasodilator with hyperdynamic hemodynamic effects in addition to significant increase in right ventricular function.

[Dermal anesthesia: comparison of the analgesic effects of 2% and 10% lidocaine gel patch].

Abstract: The analgesic effects of aqueous gel containing 2% or 10% lidocaine with 3% glycyrrhetinic acid mono 3-0 hemiphthalate sodium as an absorption promoter were compared in two volunteer groups of 12 persons each A round sponge (25 mm in diameter and 1mm in thickness) filled with approximately 03g of either gel was applied on the volar surface of the forearm and kept covered with an adhesive plastic film (Tegaderm) for two hours The analgesic effect was assessed every 30 min by pin-prick method at five places under the coverage for two hours, and after the gel was wiped away The result from each place was scored 0 (no pain) or 1 (needle pain) The mean pain scores at 1 hr and 15 hr in the 10% group were 10 and 07, and significantly lower than 22 and 13 of the 2% group (P less than 005) Two hour application of the gel, five volunteers in the 2% group and eight volunteers in the 10% group produced a pain score under 10 In these subjects, a 26 gauge needle was stuck into the skin for further pain analysis Four of the 5 subjects in the 2% group and 7 of the 8 subjects in the 10% group did not complain of any pain Transient local redness under the coverage was observed in 3 subjects in each group They were all known to be sensitive to alcoholic beverages No other side effects were found The plasma concentration of lidocaine was lower than 001 microgramml-1 at all times

The effect of corticosteroids on the recovery from vecuronium induced block

Abstract: The effects of corticosteroids (hydrocortisone, methylprednisolone) on the recovery time from the vecuronium induced neuromuscular block were studied using evoked potential measurements by stimulating ulnar nerve. Plasma concentrations of vecuronium were examined after the administration of hydrocortisone and methylprednisolone using high performance liquid chromatography in 78 surgical patients. Recovery time from the block induced by vecuronium was prolonged by corticosteroids. In case of hydrocortisone, this prolongation effect was significant (P less than 0.01). In the study of plasma concentration, blood samples were taken 40 minutes after administration of vecuronium, plasma concentration of vecuronium is significantly higher in patients given hydrocortisone (124 +/- 8.32 ng.ml-1) (mean +/- SE) than control patients (68.2 +/- 4.71 ng.ml-1) (P less than 0.001). It is speculated that corticosteroids lower the clearance of vecuronium. Prolongation of recovery time from vecuronium induced block after the administration of corticosteroids may be explained not only by the direct effect of hydrocortisone on the neuromuscular junction but also by the effect of hydrocortisone to prolong the elimination of vecuronium from plasma.

A comparison of 7 types of epidural catheters

Abstract: The stiffness on bending of 7 types of epidural catheters was measured with the help of a cantilever beam. 1415 patients scheduled for lithotripsy, requiring epidural anesthesia, were selected and randomly assigned to receive one of the catheters. The patients were divided into 2 groups according to the resistance to insertion. The incidence of intravenous insertion, subarachnoid location and paresthesia during catheter insertion were assessed. The position of epidural catheters was studied radiographically in 1276 of 1415 patients. There were no significant difference among 7 types of epidural catheters as far as the incidence of intravenous insertion, subarachnoid insertion or straight lying of catheter in epidural space were concerned. When the catheter was hard or pushed against the resistance to insertion, the incidence of paresthesia increased. When the catheter was hard and pushed against the resistance to insertion, transforaminal escape increased. A soft catheter should be chosen to minimize the incidence of paresthesia or transforaminal escape.

Sudden cardiac arrest during percutaneous nephrostolithotomy (PNL) under epidural anesthesia

Abstract: There have been few major complications of percutaneous nephrostolithotomy (PNL) reported. We recently experienced cardiac arrest during PNL under epidural anesthesia. The patient was a 52 year old man weighing 64 kg who had been suffering from right renal pelvic stone for years. He was scheduled for PLN under epidural anesthesia. Analgesia was obtained to the level of Th6. The operation proceeded uneventfully for about 60 min. By this time, he suddenly complained nausea, and hypotension with bradycardia occurred. Blood pressure and pulse rate returned immediately to the normal level by IV atropine and ephedrine. But after three minutes, blood pressure and pulse rate went down again. This hypotension with bradycardia was unresponsive to epinephrine, calcium chloride and sodium bicarbonate. This was followed by asystole. Resuscitation was successful with the addition of epinephrine, calcium chloride, and sodium bicarbonate about 15 min after cardiac massage had started. The patient was, on the fifth postoperative day, with no evidence of impairment of renal, cardiac and respiratory functions but a slight impairment of neurologic function. Several possible causes for this cardiac arrest and anesthetic management of percutaneous nephrostolithotomy are discussed.

Differentiation of brain stem anesthesia from high spinal anesthesia using auditory brain stem response

Abstract: A 67-year old woman having intractable chronic postherpetic neuralgia at the neck to forearm for two years was treated with subarachnoid block. Initially, bolus of 1% lidocaine 8 ml, with methylprednisolone acetate 20 mg was injected intrathecally at 6th cervical intervertebral space. The auditory brain stem response (ABR) during high spinal block with intact consciousness was not depressed in its wave height. ABR recorded showed prolongation of latency of 3 and 5 waves and prolongation of 1-3 phase to phase interval without prolongation of 3-5 phase to phase interval. Intrathecal nerve block was then performed with 1% lidocaine 15 ml and methylprednisolone acetate 20 mg, because she complained awareness and shocking sensation with controlled respiration during the first block. She assured that she felt nothing during the second block. The ABR recorded during the second block showed near complete suppression in its height of all waves and prolongation of all wave latencies. During recovery period, 1-3 and 3-5 phase to phase interval prolongation was recorded. One can differentiate brain stem anesthesia from other state that induces unconsciousness after block which is capable of inducing accidental brain stem anesthesia. These two blocks improved activity of daily living of the patient and severity of her pain decreased to 1/5 to 1/10.

Effects of controlled hypotension induced by prostaglandin E1 on the cerebral blood flow

Abstract: The effect of controlled hypotension induced by prostaglandin E1 (PGE1) on the cerebral blood flow (CBF) was studied in 14 patients undergoing neurosurgery. CBF was measured by thermal diffusion using a flow probe with a Peltier stack. PGE1 was injected i.v. continuously, at a dose of 0.05, 0.1 and 0.2 micrograms.kg-1.min-1. CBF tended to increase dose-dependently but not significantly by PGE1 administration. Cerebral vascular resistance was reduced significantly by every dose of PGE1 administered. Therefore, the results indicate that the cerebral vascular beds are dilated directly by PGE1. In conclusion, this study suggests that PGE1 can be used safely to control hypotension without reducing CBF during neurosurgery.

[The changes in EEG, evoked potentials and neurological recovery after global brain ischemia in dogs].

Abstract: Electroencephalography (EEG), evoked potentials and neurological recovery score were compared between 10 min and 15 min transient global brain ischemia in 18 dogs. The transient global brain ischemia was induced by occluding aorta, superior and inferior caval veins. The grade of EEG (1: normal approximately 5: flat) 2 hrs after ischemia was significantly lower with the 10 min ischemic group (n = 9) than with the 15 min group (n = 9) (3.7 +/- 0.5 vs 4.1 +/- 0.3, P less than 0.05). The rate of reappearance in evoked potential waves 2 hrs after ischemia was higher with the 10 min ischemic group than with the 15 min group (auditory brainstem response 5 wave: 100% vs 33%, middle latency response Pa wave: 80% vs 0%, somatosensory evoked potential N2 wave: 83% vs 78%, N3 wave: 67% vs 33%). The neurological recovery score (0: death approximately 100: normal) 7 days after ischemia was significantly higher with the 10 min group than with the 15 min group (58 +/- 34 vs 27 +/- 23, P less than 0.05). In both groups, there was a significant correlation (r = +0.85, P less than 0.01) between the total score of EEG and evoked potential waves (0: no wave appeared approximately 6: all waves appeared) 2 hours after ischemia and the neurological recovery score 7 days after ischemia. These results suggest that the neurological recovery after transient global brain ischemia would be estimated by EEG and evoked potential waves.

Epidural morphine and buprenorphine for postoperative pain relief after hepatectomy

Abstract: Postoperative pain relief with epidural morphine and buprenorphine was studied in 33 patients following hepatectomy. Morphine 2mg or buprenorphine 0.06mg in 10ml of normal saline was administered through an epidural catheter inserted at the Th10-11 or L3-4 interspace. Morphine injected at the lumbar level, as well as that injected at the thoracic level produced excellent and long-lasting (20.8 +/- 8.6 hours) pain relief. Respiratory rate decreased significantly following epidural morphine at the L3-4, but PaCO2 did not change. Buprenorphine injected at the thoracic level produced good and long-lasting (22.6 +/- 9.9 hours) pain relief, although buprenorphine injected at the lumbar level produced incomplete analgesia. The epidural administration of morphine 2mg at L3-4 or buprenorphine 0.06mg at Th10-11 may be recommended for postoperative analgesia following hepatectomy.

Continuous epidural infusion of bupivacaine and morphine for postoperative pain relief

Abstract: Forty-five patients admitted to the intensive care unit following thoracic or abdominal surgery received continuous epidural infusion of bupivacaine and morphine for 48 hours. During the first 10 hours, the patients received 0.25% bupivacaine solution with 0.005% morphine at the rate of 4 ml.h-1, and bupivacaine concentration was decreased to 0.125% with the same morphine concentration. The mean infusion rate of bupivacaine during 48 hours was 0.12 +/- 0.03 (SD) mg.kg-1.h-1 and that of morphine was 4.0 +/- 1.0 micrograms.kg-1.h-1. Thirty-one patients (69%) complained no pain on deep breathing at 24 hours and 33 patients (74%) required no other type of analgesics during this study. The mean plasma bupivacaine concentration was 0.6 +/- 0.3 microgram.ml-1 at 48 hours. Hypotension defined as systolic arterial pressure below 90 mmHg and itching were observed in 15 patients (33%), but no other severe side effects were noted. Continuous epidural infusion of bupivacaine and morphine mixture for 48 hours postoperatively provided effective pain relief with a low incidence of side effects.

[Study of neuromuscular transmission with evoked electromyography--10. Comparison of the responses during partial blockade by bungarotoxin and non-depolarizing relaxants].

Abstract: Effects of alpha-bungarotoxin (alpha BuTX) on muscle compound action potentials (CAPs) which were elicited from gastrocnemius muscle by sciatic nerve stimulation in cats were studied, and the results were compared with those of non-depolarizing relaxants including d-tubocurarine, pancuronium and vecuronium. The amplitude of CAP by the second member of the paired stimuli (test response) was compared with that evoked by the first component (conditioning response). The interval between the two components of the paired stimuli (the pair interval) was increased stepwise from 7 to 1,000 msec and a curve (recovery curve, RC) was obtained by relating the changes in pair interval to the difference in amplitude of the test and conditioning responses. The following results were obtained. (1) A progressive and irreversible neuromuscular block was observed after intravenous administration of alpha BuTX. During the progress of the blockade, RC of CAPs showed a pattern which was characterized by profound potentiations of test responses at shorter intervals of paired stimuli, followed by gradual recovery to similar amplitude with conditioning responses at 500 msec or over of pair interval. (2) With non-depolarizing relaxants, RC changed to the pattern of slight potentiation at a very short interval of stimuli, followed by a notable depression at longer intervals. (3) The mechanism of the development of these difference of RCs between alpha BuTX and the relaxants was discussed, and it is concluded that the notable depression of RCs derived from muscle relaxants may be caused by inhibitory effect on nerve terminals of these relaxants, and the inhibition was more prominent with d-tubocurarine than with other two relaxants.

Clinical study of propofol in male volunteers

Abstract: A clinical phase 1 study of intravenous anesthetic, propofol, was carried out in 6 male volunteers. Propofol, 1, 2, and 2.5 mg.kg-1, was administered intravenously. Anesthetic effects and effects on vital signs, such as blood pressure, heart rate, respiratory rate and body temperature, were investigated. Any adverse effects or abnormal laboratory findings were also investigated. Venous blood samples were obtained frequently for 12 hours to measure blood propofol concentrations. One volunteer out of 6 lost consciousness with 1 mg.kg-1 and the remaining with 2 mg.kg-1 within 1.5 min. In 2 volunteers the duration of anesthesia was inadequate for clinical practice with 2 mg.kg-1. Therefore, 2.5 mg.kg-1 was given. Rhythmic high voltage slow waves appeared immediately after the loss of consciousness in EEG and then basic activity changed to 11 approximately 16 Hz, 30 approximately 60 microV. Blood pressure decreased and heart rate increased but no profound hypotension was observed. Body temperature decreased. No adverse effect, such as laryngospasm, bronchospasm or hiccough, occurred. Laboratory test showed no abnormal result. Pharmacokinetic analysis was carried out using a 3 compartment open model. The half time of distribution phase, 2.6 min, was short, and total clearance, 1.68 l.min-1, was high. We conclude that the proper induction dose of this agent is 2 approximately 2.5 mg.kg-1, which is similar to the values previously reported in European investigations, and that this agent is safe and useful for induction of anesthesia.