Clonidine-ephedrine combination reduces pain on injection of propofol and blunts hemodynamic stress responses during the induction sequence.

STUDY OBJECTIVES: To evaluate the effects of clonidine and ephedrine on propofol-induced pain and on hemodynamic changes during the induction sequence. DESIGN: This was a prospective, randomized, double-blind study. SETTING: The study was conducted at a university hospital. PATIENTS: 200 ASA physical status I or II adult patients scheduled for elective surgery. INTERVENTIONS: Patients were randomly allocated to one of 4 groups (50 patients per group): clonidine-ephedrine (CE), clonidine-saline (CS), diazepam-ephedrine (DE), and diazepam-saline (DS). Thirty seconds after the administration of ephedrine or saline, propofol 2 mg/kg was infused at a rate of 18.3 mL/min. MEASUREMENTS: Patients were asked whether they had pain due to propofol injection. A blinded investigator evaluated the pain score: 0 = no pain, 1 = mild pain, 2 = severe pain without behavioral signs such as grimace or arm withdrawal movement, and 3 = severe pain accompanied by behavioral signs. Mean arterial blood pressure (MAP) and heart rate (HR) were measured at 1-minute intervals from just before the administration of ephedrine or saline to 5 minutes after the tracheal intubation. MAIN RESULTS: Median pain score in CE was significantly lower than those in the other groups (P < 0.0001). Pain scores in CS and DE were significantly lower than that in DS (P < 0.05). Ephedrine increased HR in CE and DE (P < 0.05), but clonidine did not augment the effect. Mean arterial blood pressure before tracheal intubation decreased to comparable values in all groups. After the intubation, mean arterial blood pressure and HR in CE and CS were significantly lower than those in DE and DS (P < 0.05). CONCLUSIONS: Combination of clonidine and ephedrine effectively reduced propofol-induced pain, but did not prevent propofol-induced hypotension. Clonidine did not augment low dose of ephedrine-induced increase in HR and produced stable hemodynamic condition during the induction sequence.

[Anesthetic managements of the patients receiving catheterizable cecostomy].

To improve the quality of life of patients suffering from spinal cord injury, "Catheterizable cecostomy" operation have recently been carried out. In the procedure, cathetelizable stoma is opened and patients are able to control the excretion by injecting enema solution through the stoma. Although operations are usually performed under general anesthesia with tracheal intubation, special considerations sometimes need to be taken for airway management. In such cases, we select spinal anesthesia. Because the surgery is achieved on a fixed charge, efficiency of pre-operative assessment should be done for the cost-cutting with shortening of perioperative period. Diseases including hypertension, diabetes mellitus, etc., must be controlled before admission to the hospital. With these considerations, proper pre-operative assessment can be made.

[Effects of clonidine and midazolam on postoperative shivering, nausea, and vomiting].

BACKGROUND: Postoperative shivering, nausea, and vomiting are common problems after general anesthesia. We compared the effects of clonidine and those of midazolam on postoperative shivering, nausea and vomiting in elderly patients. METHODS: We studied 40 elderly patients (age > 60 yr) undergoing elective surgery under general anesthesia combined with epidural anesthesia. Patients were allocated randomly to receive oral clonidine 3-4 microg x kg(-1) (clonidine group) or intramuscular midazolam 0.04-0.05 mg x kg(-1) (midazolam group). Anesthesia was maintained with sevoflurane in a nitrous oxide and oxygen mixture, and fentanyl as needed, combined with epidural anesthesia with mepivacaine. Shivering, nausea, and vomiting were recorded at recovery from anesthesia, 3 h after the transference to the ward, and the next morning. Shivering was graded by using a three-point rating scale, whereas nausea and vomiting were assessed by means of a four-point rating. RESULTS: The incidence of shivering was lower at recovery from anesthesia in the clonidine group (P < 0.05). Likewise, the incidence of nausea was lower at recovery from anesthesia in the clonidine group (P < 0.05). There were no differences in shivering and nausea at other recording points. One patient in each group had vomiting. CONCLUSIONS: Clonidine premedication is effective for preventing shivering and nausea after general anesthesia combined with epidural anesthesia.

Epidural ropivacaine anesthesia decreases the bispectral index during the awake phase and sevoflurane general anesthesia.

The sedative effects of epidural anesthesia without volatile and IV anesthetics and quantification of the degree of epidural anesthesia-induced sedation have not been investigated. In the current study we evaluated the effects of epidural anesthesia on the bispectral index (BIS) during the awake phase and during general anesthesia. After placing the epidural catheter, the patients were randomly allocated to 2 groups receiving either 5 mL of epidural saline (group S) or the same volume of 0.75% ropivacaine (group R). The BIS measurements during the awake phase were performed at 7, 12, 13, 14, 22, and 23 min after the epidural injection. General anesthesia was then induced with propofol and vecuronium and maintained with 0.75% sevoflurane. From approximately 10 min after tracheal intubation, the BIS measurements were made at 1-min intervals for 10 min. The BIS during the awake phase was significantly lower in group R than in group S (P < 0.05). The BIS during general anesthesia was significantly lower in group R than in group S (P < 0.0001). Epidural anesthesia decreased the BIS during the awake phase and during general anesthesia. The decrease of the BIS associated with epidural anesthesia was more prominent during general anesthesia than during the awake phase.

[Refractory generalized convulsions in a patient undergoing brain tumor resection during propofol anesthesia].

Propofol has been used to treat convulsions, while the drug is known to induce convulsions. We described a case of generalized convulsions during brain tumor resection under propofol anesthesia. A 24-year-old man was scheduled to undergo brain tumor resection. He had no history of epilepsy. Anesthesia was induced and maintained with propofol and fentanyl. During the craniotomy, the patient developed generalized convulsions. Diazepam, thiamylal, and phenytoin were given intravenously and the seizure activity resolved. Generalized convulsions recurred three times during the operation. Postoperative course was uneventful. On the 16 th postoperative day, the patient underwent ventriculoperitoneal shunt under general anesthesia using sevoflurane, nitrous oxide and oxygen. Convulsions were not noted intra- and postoperatively. Because convulsions did not occur during sevoflurane anesthesia and the patient had no history of epilepsy, propofol may have induced a generalized convulsions on the first operation.

[Anesthetic management of three patients with myotonic dystrophy in a family].

Case-1: A 24-year-old woman was admitted because of pressing hydramnion. She was treated by ritodrine hydrochlorides leading to rhabdomyolysis, and she was diagnosed as myotonic dystrophy. She underwent cesarean section because of urgent premature birth. The surgery was performed with spinal anesthesia using tetracaine. Case-2: A 1-year-old boy, the son of Case 1, underwent orchiopexy. He showed respiratory distress at birth and needed respiratory support for 140 days. The surgery was performed under general anesthesia combined with caudal anesthesia. Anesthesia was induced with nitrous oxide-oxygen-sevoflurane. He was intubated without muscle relaxants. Since he recovered consciousness soon after the surgery, he was extubated and returned to the ward. Case-3: A 30-year-old woman, the sister of Case 1, underwent tonsillectomy. At the age of 27 she underwent salpingectomy under general anesthesia with nitrous oxide-oxygen-halothane, after which she was diagnosed as myotonic dystrophy. She was anesthetized with propofol and fentanyl. Because severity of the myotonic dystrophy varies among the patients, the strategy for anesthesia should be planned on each patient. Generally speaking, regional anesthesia including spinal and epidural anesthesia is preferable.

[Double-lumen tracheostomy tube (Tracheopart) used in two patients for one-lung ventilation under general anesthesia].

Double-lumen tracheostomy tube (Tracheopart, RUSCH) is now available in Japan. We used the device to perform one-lung ventilation in two patients with previous laryngectomy and permanent tracheostomy. Reliable fixation and observation of the right position during the operation are especially important throughout the procedure. We think that this device needs more improvements regarding its size and length.

[Two occasions of anesthetic management for a patient with Williams syndrome].

A 5-year-old boy with Williams syndrome received open reduction of fracture of the antebrachium twice. He had been diagnosed as having Williams syndrome with some characteristic symptoms, including elfin face, mental retardation and primary pulmonary hypertension. Williams syndrome has a tetrad of cardiovascular disease, elfin face, mental retardation and hypercalcemia. Operations were performed twice under general anesthesia. Airway management with mask technique was easily performed. Tracheal intubation was accomplished successfully. Anesthesia was induced with propofol, fentanyl, and vecuronium, and maintained with propofol, fentanyl and the inhalation of oxygen with nitrous oxide. Both anesthetic courses were uneventful and he was discharged without any complications. Special anesthetic considerations should be taken for difficulties of intubation, management of circulatory system, malignant hyperthermia, and hypercalcemia in this syndrome.

Doxapram produces a dose-dependent reduction in the shivering threshold in rabbits.

Dopamine is a thermoregulatory neurotransmitter that provokes hypothermia when injected in or near the hypothalamus. Doxapram stimulates release of dopamine from carotid bodies, but is known to have central effects that are probably, at least in part, similarly mediated. We thus tested the hypothesis that doxapram produces a substantial, dose-dependent reduction in the shivering threshold in rabbits. Twenty-four rabbits, anesthetized with isoflurane, were randomly assigned to 1) saline (control), 2) 0.25 mg x kg(-1) x h(-1) doxapram, or 3) 0.50 mg x kg(-1) x h(-1) doxapram. These doses are within the recommended range for humans. Body temperature was reduced at a rate of 2 degrees to 3 degrees C/h by perfusing water at 10 degrees C through a U-shaped thermode positioned in the colon. Core temperatures were recorded from the distal esophagus. A blinded observer evaluated shivering. Core temperature at the onset of shivering defined the threshold. Data were analyzed with a one-way analysis of variance; P < 0.05 was considered statistically significant. Hemodynamic and respiratory responses were comparable in the groups. The control rabbits shivered at 36.3 degrees +/- 0.3 degrees C, those given 0.25 mg x kg(-1) x h(-1) doxapram shivered at 34.8 degrees +/- 0.5 degrees C, and those given 0.50 mg x kg(-1) x h(-1) shivered at 33.7 degrees +/- 0.6 degrees C. All the shivering thresholds significantly (P < 0.001) differed from one another. The magnitude of this inhibition, if similar in humans, would be clinically important.

Ephedrine, but not phenylephrine, increases bispectral index values during combined general and epidural anesthesia.

Ephedrine and phenylephrine are used to treat hypotension during combined general and epidural anesthesia, and they may change anesthetic depth. In the current study, we evaluated the effects of ephedrine versus phenylephrine on bispectral index (BIS) during combined general and epidural anesthesia. After injection of ropivacaine through the epidural catheter, general anesthesia was induced with propofol and vecuronium, and was maintained with 0.75% sevoflurane. Approximately 10 min after the intubation, BIS was recorded as a baseline value. Patients with decreases in arterial blood pressure <30% of the preanesthetic values were defined as control group (n = 9). Patients who had to be treated for larger decreases in arterial blood pressure were randomly assigned to receive ephedrine 0.1 mg/kg (n = 17) or phenylephrine 2 micro g/kg (n = 17). BIS values were recorded at 1-min intervals for 10 min. BIS in the ephedrine group was significantly larger from 7 to 10 min than that in the control and phenylephrine groups (P < 0.05). Seven patients in the ephedrine group had BIS >60, whereas no patient in the control and phenylephrine groups had BIS >60 (P < 0.005). Ephedrine, but not phenylephrine, increased BIS during general anesthesia combined with epidural anesthesia.

[Effect of prostaglandin E1 infusion during and after total hip arthroplasty under hypotensive anesthesia on postoperative renal function and urine volume].

BACKGROUND: We evaluated the effect of prostaglandin E1 (PGE1) on the renal function and urine volume after total hip arthroplasty (THA). METHODS: Twenty patients with normal renal function were randomly divided into two groups. The patients were anesthetized with spinal anesthesia using 0.5% bupivacaine 4 ml and epidural anesthesia. The laryngeal mask was inserted after administrations of 1.5-2 mg.kg-1 of propofol and 0.8 mg.kg-1 of suxamethonium. PGE1 was infused in the PGE1 group at a rate of 0.01 microgram.kg-1.min-1 (PGE1 group) during and after the operation (60-80 hrs). BUN and Crt values were evaluated before, and at the end of operation, and on 1, 4, and 7 postoperative days in each group. The amount of urine volume was measured at the end of operation and on 0, 1, 2, 3, and 4 postoperative days in each group. RESULTS: BUN and Crt values after the operation did not differ significantly between the two groups. The amounts of urine volume on 2, 3, and 4 postoperative days in PGE1 group were significantly higher than those in the control group. Moreover, total urine volume in PGE1 group was significantly higher than that in the control group. CONCLUSIONS: These results suggest that PGE1 may prevent postoperative decrease of urine volume, but it may not affect postoperative renal function.

Core temperature monitoring with new ventilatory devices.

UNLABELLED: Widespread use of new airway devices, such as the laryngeal mask airway (LMA) and the cuffed oropharyngeal airway (COPA), preclude measuring core temperature in the distal esophagus. Therefore, we tested the hypothesis that core temperature measured with a thermocouple positioned on a LMA or COPA is sufficiently accurate and precise for clinical use. Temperatures were recorded from thermocouples positioned on the cuffs of LMAs or COPAs in 36 patients scheduled for prolonged orthopedic surgery or therapeutic hyperthermia for cancer. These temperatures, recorded at 15-min intervals, were compared with simultaneously obtained nasopharynx and tympanic membrane temperatures. Data were compared by linear regression and the bias calculated. Temperatures measured on the LMA correlated well with both nasopharyngeal (r(2) = 0.94) and tympanic membrane (r(2) = 0.94) temperatures. Temperatures measured on the COPA also correlated well with those on the nasopharynx (r(2) = 0.97) and tympanic membrane (r(2) = 0.96). The fraction of temperatures that differed from nasopharynx temperature by more than +/-0.5 degrees C was 8% with LMA and 11% with COPA; the fraction of temperatures that differed from tympanic temperature by more than +/-0.5 degrees C was 7% with LMA and 10% with COPA. These results suggest that body temperature measured from the cuffs of COPA or LMAs is sufficiently accurate for routine clinical use. IMPLICATIONS: Temperatures measured on airway devices correlated well with independent measurements of core body temperature. Thus, body temperature measured on the cuffs of airway devices is sufficiently accurate for routine use.

Systemic, but not pulmonary, hemodynamics are depressed during combined high thoraco-cervical epidural and general anesthesia in dogs.

PURPOSE: An epidural block is frequently combined with general anesthesia. Both systemic and pulmonary hemodynamics may be affected by high epidural anesthesia and the combined general anesthetic. These effects were investigated in a canine model. METHODS: Systemic and pulmonary hemodynamics during a combined high thoraco-cervical epidural and general anesthesia were studied in dogs; the animals were anesthetized with propofol, 10 mg.kg(-1).hr(-1), or 2% sevoflurane, and then 1% mepivacaine, 5 mL, was injected epidurally between T1 and T2. Cardiac output (CO), pulmonary capillary wedge pressure (PCWP), pulmonary arterial pressure (PAP), mean arterial pressure (MAP), central venous pressure (CVP), electrocardiogram, and arterial and mixed venous gases were monitored for over 90 min after epidural mepivacaine. The interval between sevoflurane and propofol studies was two hours. RESULTS: Baseline measurement of MAP with sevoflurane anesthesia was significantly lower (P < 0.05-0.01) at every time point than with propofol anesthesia. After epidural mepivacaine (C1)-T7/8 blockade), MAP (P < 0.05-0.01), CO (P < 0.05-0.01), and heart rate (P < 0.05-0.01) decreased significantly during both propofol and sevoflurane anesthesia. In the sevoflurane group, stroke volume decreased significantly (P < 0.05-0.01) but recovered; however, MAP (P < 0.01) and CO (P < 0.05) did not recover 90 min after the injection. Mean CVP and systemic vascular resistance were not altered. There were no changes in mean PAP, mean PCWP, and pulmonary vascular resistance. CONCLUSION: A combined high thoracic/general anesthesia depressed systemic hemodynamics, whereas the pulmonary circulation was not affected. The extent of the depression varied with the general anesthetics used, sevoflurane and propofol.

[Anesthetic management in a patient complicated with left coronary artery-left ventricular fistulae].

We have experienced anesthetic management for posterior lumbar interbody fusion in a 76-year-old female with left coronary artery-left ventricular fistulae. She was admitted to our hospital because of chest pain and was found to have left coronary artery-left ventricular fistulae 6 months before this operation. The electrocardiogram at rest showed T-wave inversions in leads V3-V6. Selective coronary angiography showed the contrast medium streaming into the left ventricle via a maze of fine vessels from the distal left anterior descending coronary artery. Cardiac catheterization revealed left ventricular end-diastolic pressure of 30 mmHg and mean pulmonary capillary wedge pressure of 16 mmHg. Anesthesia was induced with intravenous propofol 60 mmHg, fentanyl 0.1 mg and vecuronium 6 mg, and maintained with 50% nitrous oxide and isoflurane (0.5-1.5%) in oxygen with meticulous intravenous administration of fentanyl. Cardiac function was evaluated with Swan-Ganz catheter during anesthesia. Dopamine and prostaglandin E1 ware continuously infused intravenously to decrease high afterload and maintain cardiac output. The operative and post-operative courses were uneventful. Coronary artery-left ventricular fistulae are extremely rare and can cause myocardial ischemia from coronary steal. A careful management with meticulous anesthetic care is emphasized for patients with coronary artery-left ventricular fistulae.

The effects of clonidine premedication on the blood pressure and tachycardiac responses to ephedrine in elderly and young patients during propofol anesthesia.

UNLABELLED: We studied the pressor and tachycardiac responses to ephedrine in elderly and young patients given either clonidine or midazolam during propofol anesthesia. In the first experiment, elderly (>60 yr) and young (20-45 yr) patients were randomly allocated to one of four groups according to age and premedicated regimens (n = 16 each; elderly-clonidine [EC], elderly-midazolam [EM], young-clonidine [YC], and young-midazolam [YM]). Under propofol anesthesia, ephedrine was injected, and hemodynamic measurements were made. In the second experiment, with clonidine premedication, elderly patients (n = 16) were given a reduced dose of propofol (EC-LP) and young patients (n = 16) were given an increased dose of propofol (YC-HP). Ephedrine was injected, and he- modynamic measurements were performed. The in-creases in mean blood pressure and heart rate were larger in the EC group than in the EM, YM, and EC-LP groups (P < 0.05). In the YC-HP group, the pressor response to ephedrine tended to be augmented as compared with the YC group but was not statistically significant. These results suggest that clonidine premedication augmented the pressor and tachycardiac responses to ephedrine, especially in elderly patients during a standard dose of propofol anesthesia, and that clonidine, age, and propofol could be involved in the augmentation of the blood pressure and tachycardiac responses to ephedrine. IMPLICATIONS: Clonidine premedication augments the pressor and tachycardiac responses to ephedrine in elderly patients during standard or large doses of propofol anesthesia but does not augment during small doses of propofol anesthesia. Clonidine, age, and propofol could be involved in the augmentation of the pressor and tachycardiac responses to ephedrine.

[Compartment syndrome in a young male caused by acute alcoholic rhabdomyolysis].

We report a case of young male who developed compartment syndrome of his left leg caused by rhabdomyolysis following a heavy binge of alcohol. The laboratory data on his admission revealed extremely elevated serum levels of CPK (108,021 IU.l-1). The serum levels of potassium and creatinine were within normal ranges. He also had myoglobinuria. He required fasciotomy after admission. Diuretics and a large volume of fluids were given to prevent the renal failure. His postoperative course was uneventful. The direct toxic effects of alcohol and the prolonged ischemia of his lower leg induced by acute alcoholic intoxication, are thought to have played a major role in the triggering of the acute rhabdomyolysis. Acute alcoholic rhabdomyolysis should be considered in any intoxicated patient who presents muscle tenderness and weakness. The early recognition and prompt treatment are essential to prevent serious complications.

[Pretreatment with lidocaine accelerates onset of vecuronium-induced neuromuscular blockade].

The purpose of this study was to investigate the effect of pre-treatment with lidocaine on the onset of vecuronium-induced neuromuscular block in a randomized, double-blinded trial. Thirty-one patients were randomly allocated to one of two groups according to the agents administrated 3 min prior to vecuronium injection; Group C, normal saline 0.75 ml.kg-1 and Group L, 2% lidocaine 1.5 mg.kg-1. Anesthesia was induced with propofol 1.5 mg.kg-1 followed by continuous infusion at 8 mg.kg-1.hr-1. Neuromuscular blockade was evaluated with accelerometry, which measured a train-of-four (TOF) pattern of abductor policies muscle. The disappearance of the first response in TOF was regarded as onset of neuromuscular block. Changes in systolic and diastolic arterial pressure (SBP, DBP) and heart rate (HR) were measured before and after tracheal intubation. Times to onset of neuromuscular blockade induced by vecuronium in Group L and Group C were 115 +/- 20 sec and 174 +/- 45 sec, respectively. After tracheal intubation, SBP, DBP and HR in both groups increased compared with those before tracheal intubation, but the changes were not significant. Changes in SBP, DBP and HR did not differ between Group L and Group C. The mechanisms by which lidocaine reduced the time to onset of neuromuscular block caused by vecuronium could not be clarified from our study, but this may be related to pre- and post-junctional effects of lidocaine at neuromuscular junction. In conclusion, administration of lidocaine prior to tracheal intubation reduces the time to onset of neuromuscular block caused by vecuronium, but does not attenuate changes in blood pressure and heart rate caused by tracheal intubation.

[Anesthetic management of two patients with the history of SMON].

Patients of subacute myelo-optico-neuropathy (SMON) suffer from neurological disorders for a long time. The authors report anesthetic management of two patients with SMON. One patient was a 82-year-old woman suffering from SMON for 49 years. Sensory examination revealed numbness and hypesthesia in the both lower extremities. She underwent open reduction for femoral neck fracture. The other patient was a 91-year-old man suffered from SMON for 31 years. Sensory examination revealed weakness of leg muscles. He underwent transurethral resection of prostate. We chose general anesthesia for both patients instead of spinal anesthesia because of reported complications related to spinal anesthesia in patients with the disease. Intraoperative courses were uneventful and there were no neurological deteriorations postoperatively in both patients. One of the chief symptoms of patients with SMON is numbness of the lower extremity. Therefore patients of SMON may feel uncomfortable to the numbness by spinal or epidural anesthesia. This is the main reason we recommend general anesthesia for patients with SMON.