Alfentanil used to supplement propofol infusions for oesophagoscopy and bronchoscopy

This randomised double-blinded study compared the cardiovascular stability and rate of recovery when propofol infusions with or without alfentanil were used to provide anaesthesia for rigid oesophagoscopy and (or) bronchoscopy. Forty-six patients were allocated randomly to receive either alfentanil 10 micrograms/kg or saline just before a rapid sequence induction with propofol. Suxamethonium 1 mg/kg was given and infusions of suxamethonium 10 mg/minute and propofol (10 mg/kg/hour for 10 minutes, 8 mg/kg/hour for 10 minutes and then 6 mg/kg/hour thereafter) were started. There were 23 patients in each group with no significant demographic differences between the groups. A significantly mean lower induction dose of propofol was needed in the alfentanil group (1.7 mg/kg compared to 2.2 mg/kg). Cardiovascular measurements were made on the ward pre-operatively, just before induction, just after induction, just after intubation, and at 3-minute intervals thereafter. Arterial pressure was significantly lower during the procedure in the patients who received alfentanil and there was a significant incidence of hypotension. There was no significant difference between the groups in respect of heart rate, with a significant increase in both groups just after intubation compared to the baseline values. Recovery from anaesthesia was assessed using the critical flicker fusion threshold. No differences were found between the groups and patients in both groups had returned to baseline values by 60 minutes. No patient had any recall of intra-operative events, and there were no other adverse effects of any significance.     

Total intravenous anaesthesia with propofol or etomidate

In combination with fentanyl, propofol was compared with etomidate for total intravenous anaesthesia in 21 women (ASA Grades I-II) admitted for elective hysterectomy. They received either propofol (bolus 1.5 mg kg-1, infusion 9 mg kg-1 h-1 for 10 min thereafter 6 mg kg-1 h-1) or etomidate (bolus 0.10 mg kg-1, infusion 3 mg kg-1 h-1 reduced to 0.6 mg kg-1 h-1). Fentanyl 10 micrograms kg-1 was given for induction followed by an infusion of 30 micrograms kg-1 h-1 for 10 min reduced to 6 micrograms kg-1 h-1 for the first hour and successively reduced over time. Induction was smooth and maintenance easy to manage in both groups. There was no difference in time from end of infusion until extubation, but the time until the patients could report their date of birth was significantly shorter in the propofol group. Nausea and vomiting were more pronounced in the etomidate group, and mental side-effects were only seen after etomidate. After 3 months, more patients in the etomidate group complained of reduced power of concentration. We conclude that total intravenous anaesthesia with either propofol or etomidate is equally easy to manage, but in the recovery situation propofol was advantageous in time and quality.     

Propofol for induction and maintenance of anaesthesia at Caesarean section A comparison with thiopentone/enflurane

A propofol infusion regimen and a standard general anaesthetic were compared in 40 Chinese women undergoing elective Caesarean section. Twenty patients received propofol 2 mg/kg for induction of anaesthesia followed by propofol 6 mg/kg/hour, while 20 patients received thiopentone 4 mg/kg with enflurane 1% for maintenance of anaesthesia. All patients were given atracurium and their lungs ventilated with nitrous oxide 50% in oxygen until delivery of the neonate. The hypertensive response after intubation was of shorter duration in the propofol group compared with the thiopentone group. Induction to delivery times ranged from 5 to 14 minutes and neonates from both groups had similar and satisfactory Apgar scores. Neurologic and Adaptive Capacity Scores and umbilical cord blood gas analysis. However, a prolonged propofol infusion time before delivery may cause lower Neurologic and Adaptive Capacity Scores. There were no differences in maternal recovery times or psychomotor performance.     

Propofol and alfentanil infusion

In 42 patients undergoing major surgery, anaesthesia was induced by intravenous alfentanil 10 micrograms/kg together with methohexitone 1.5 mg/kg or propofol 2 mg/kg. An infusion of six times these doses per hour was then started; the rate was varied subsequently as indicated by the monitoring of arterial blood pressure, heart rate, EEG and frontalis electromyogram. The mean duration of infusion was 76.7 minutes for propofol and 74.5 minutes for methohexitone and the infusion was stopped about 10 minutes before the end of surgery in each group. The induction dose differed, but the total dose requirement for the two drugs was similar. In every case, anaesthesia was satisfactory. Methohexitone caused a significant rise in mean pulse rate throughout anaesthesia (p less than 0.05, paired t-test). There was no change in mean pulse rate during propofol infusion. The dose of alfentanil used provided excellent control of autonomic reflexes, with negligible respiratory depression. Naloxone was not required. Propofol provided better anaesthesia than methohexitone, with fewer side effects (p less than 0.05, Chi squared test), easier control of the level of narcosis and faster recovery (p less than 0.001, t-test after log transformation).     

Myocardial metabolism as affected by propofol in geriatric patients. A comparison with etomidate

This study was designed to compare the effects of propofol and etomidate on myocardial metabolism in elderly patients without clinical manifestations of heart failure or coronary artery disease. Twenty geriatric patients (age 65-82 years) scheduled to undergo elective major upper-abdominal surgery were studied and randomly allocated to two equal groups (propofol and etomidate). All patients were premedicated with piritramide, 7.5 mg, and promethazine, 25 mg, intramuscularly 1 h before arrival in the anesthesia room. Ten patients received propofol (1.5 mg/kg) for induction of anesthesia, followed by 10-min infusion of an induction dose; thereafter, anesthesia was maintained with a continuous infusion of 0.1 mg/kg per min. Ten patients received etomidate, 18 mg, for induction, followed by 2.4 mg/min for maintenance. Vecuronium was used for neuromuscular blockade. Cardiovascular dynamics were recorded while the patients were awake, 1-2 min after induction during apnoea, and 1, 5 and 30 min after tracheal intubation without surgical stimulation. Coronary blood flow (argon wash-in technique with sampling of blood from the coronary sinus), myocardial oxygen consumption and myocardial uptake of glucose, free fatty acids and lactate were determined in the awake state and 5 and 30 min after intubation. Arterial plasma concentrations of propofol (high-pressure liquid chromatography with fluorescence detection) and etomidate (gas chromatography) were measured every 5 min throughout the investigation period, which lasted 45 min. Overall mean plasma concentrations of propofol were 3.69 +/- 0.16 micrograms/ml and of etomidate 1.1 +/- 0.16 microgram/ml.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recovery from propofol infusion as the main agent for outpatient arthroscopy

Propofol by continuous intravenous infusion has been compared with isoflurane as the main anaesthetic agent for outpatient arthroscopy of the knee. In 40 unpremedicated patients, anaesthesia was induced with propofol 2 mg/kg and vecuronium bromide 0.1 mg/kg and maintained after tracheal intubation with nitrous oxide 66% in oxygen. One group received 3% isoflurane prior to intubation and 0.9% during maintenance, while the other received a continuous intravenous infusion of propofol at a rate of 10 mg/kg/hour. Recovery was assessed by the time to opening eyes, to be able to answer five questions correctly, to recovery of ocular balance (Maddox Wing test) and by comparing pre- and postoperative performance in a paper and pencil test (the p-deletion test). After 3 hours all the patients were fit for discharge. Recovery tests showed no differences between the groups. All patients were satisfied with the anaesthesia. Full recovery took on average 1.5 days (range between 1 hour and 14 days) in both groups. Patients' opinion 1 month after the procedure should be included in every study concerning recovery. Anaesthesia by continuous propofol infusion results in quick recovery comparable with that following isoflurane anaesthesia.     

Propofol combined with nitrous oxide-oxygen for induction and maintenance of anaesthesia

After a bolus of 2 mg/kg, propofol was given by continuous infusion (150 micrograms/kg/minute for 30 minutes and then 100 micrograms/kg/minute) supplemented with nitrous oxide for anaesthesia during ear surgery in 12 patients. Cardiovascular changes were not significant except for a decrease in heart rate after 60 minutes. Acid-base balance was unaffected by the amount of fatty emulsion. Cortisol levels showed a nonsignificant decrease during the prolonged administration of propofol but had recovered completely by one hour following anaesthesia. Mean blood concentrations of propofol were 10.5 micrograms/ml (SEM 1.2) at the onset of unconsciousness, between 3.4 and 4.5 micrograms/ml during continuous infusion and 2.9 micrograms/ml (SEM 0.3) on awakening. Patients opened their eyes 6 minutes (SEM 1) after discontinuation of the infusion, and were responsive at 7.5 minutes (SEM 0.5), which suggests that propofol infusion can be used safely for surgery of 2 hours' duration.     

Effects of nitrous oxide on haemodynamic and electroencephalographic responses induced by tetanic electrical stimulation during propofol anaesthesia

We studied the effect of nitrous oxide on haemodynamic and electroencephalographic responses caused by noxious stimulation during propofol anaesthesia. Thirty-four patients (ASA I-II) were anaesthetised with propofol 3 mg x kg(-1) and were randomly allocated to receive either 60% nitrous oxide in oxygen or 40% oxygen in air. Anaesthesia was maintained using propofol infusion of 10 mg x kg(-1) x h(-1) for the first 10 min, 8 mg x kg(-1) x h(-1) for the next 10 min and 6 mg x kg(-1) x h(-1) thereafter. Thirty minutes after the induction of anaesthesia, tetanic electrical stimulation (80 mA, 100 Hz) was applied to the ulnar nerve. Tetanic stimulation significantly increased blood pressure and heart rate in both groups (p < 0.005 or less), but did not induce any arousal pattern on the electroencephalograph. Nitrous oxide significantly attenuated the tetanic stimulation-induced increase in blood pressure (p < 0.05 or less), but not the heart rate.     

The use of propofol during diskectomy in neurosurgery]

The intravenous anaesthetic agent propofol has become more and more popular not only for induction but also for the maintenance of anaesthesia in all fields of surgery. For this purpose, different infusion rates and also combinations of propofol with opioids, nitrous oxide and volatile anaesthetic agents have been described. The present study was designed to find the best dosage regimen for short operations and rapid changes. The necessity for the frequently recommended standardized combination of propofol with opioids should be checked with respect to the cardiovascular effects. METHODS. A series of 60 patients (ASA I and II, age range 22-79 years) selected for discectomy were prospectively randomized to three groups. Half an hour before operation all patient received 0.5 mg atropine, 50 mg promethazine and 50 mg pethidine as i.m. premedication. In all groups anaesthesia was induced with propofol in a bolus dose of 2.5 mg/kg body weight over a period of approximately 45 s. After 5 mg atracurium the patients were intubated under 100 mg succinylcholine and normoventilated with 70% nitrous oxide and 30% oxygen. For relaxation 25 mg of atracurium were given. In group I propofol was administered in a dosage of 15 mg/kg body weight per hour for 10 min after induction. After this time the propofol infusion was reduced to 6 mg/kg body weight per hour. Group II received 0.1 mg fentanyl before induction. The dosage of propofol was similar to group I. In group III 0.1 mg of fentanyl was administered before induction and propofol was given with an infusion rate of 6 mg/kg body weight from the beginning. The following parameters were controlled and documented: systolic and diastolic blood pressure (SAP and DAP), heart rate (HF), end-expiratory carbon dioxide (eeCO2), inspiratory oxygen concentration (FiO2) and peripheral oxygen saturation (sO2). Recovery time was determined as the time from the end of the propofol infusion until eye-opening on command. RESULTS. In all groups anaesthesia could be induced and maintained without complications. There was a slight increase in SAP in group I after intubation, while in the groups with fentanyl a pronounced decrease of SAP was found simultaneously with induction of anaesthesia (Fig. 1). In group I HF showed significantly higher values after intubation and for the next 15 min than in group II and group III. A rapid and pronounced increase of end-tidal carbon dioxide occurred in the fentanyl groups with the beginning of spontaneous ventilation at the end of anaesthesia. There was a significantly longer recovery time in group II with fentanyl and initial higher propofol infusion rate. A correlation between dosage of propofol and recovery time could not be found. DISCUSSION. The results of this study demonstrate that a routine combination of propofol with opioids is not necessary even for painful surgical procedures if the propofol dosage is initially increased. There are differences in cardiovascular reactions between group I without and groups II and III with fentanyl, but in our patients these changes were of no clinical importance. An additional administration of fentanyl can prevent hypertensive reactions or tachycardia with intubation, but on the other hand fentanyl can also increase the cardial depression of propofol with a dangerous decrease in blood pressure and heart rate. Therefore in combination with opioids lower doses of propofol should be used for induction and maintenance of anaesthesia. If opioids are administered, signs of a residual postoperative respiratory depression have to be taken seriously.     

Propofol for intravenous sedation

This study investigated the properties of propofol when given by subanaesthetic infusion to provide sedation as an adjunct to spinal anaesthesia for lower limb surgery in 40 patients. Sedation, defined as sleep with preservation of eyelash reflex and purposeful reaction to verbal or mild physical stimulation, was satisfactorily achieved and maintained with minimal complications. The mean duration of infusion was 98 minutes and a mean infusion rate of 3.0 mg/kg/hour was required in patients over 65. This was significantly less (p less than 0.005) than the 4.1 mg/kg/hour required in younger patients. Recovery was impressively rapid; patients regained full consciousness approximately 4 minutes after the end of infusion, and were free from minor postoperative sequelae. Conversion to general anaesthesia was achieved in three patients where surgery encroached outside the analgesic field of the regional block, simply by increasing the infusion rate to approximately 10 mg/kg/hour.     

Anesthesia for heart catheterization in children. Comparison of 3 techniques]

A study was carried out to compare the haemodynamic and respiratory effects, as well as the quality of recovery, of anaesthesia with ketamine, sodium gamma-hydroxybutyrate (GOH) and etomidate in children undergoing cardiac catheterization. Thirty children, mean age 48 +/- 35 months, ranked ASA 2 or 3 on account of congenital heart disease, were assigned to one of three groups (n = 10). They were given: in group E1, a 0.3 mg.kg-1 bolus of etomidate, followed by 0.1 mg.kg-1.min-1 for 10 minutes, and 0.026 mg.kg-1.min-1 thereafter; in group G2, a 50 mg.kg-1 bolus of GOH, and in group K3, a 4 mg.kg-1 bolus of ketamine followed by a continuous infusion of 0.083 mg.kg-1.min-1. The patients breathed spontaneously. Monitoring included heart rate, systolic, diastolic and mean blood pressure, pulse oximetry, and capnography. Femoral venous or arterial catheterization was performed after local anaesthesia (with no more than 2 mg.kg-1 of lidocaine). Measurements were performed before induction, and then 1, 10, 30 and 60 minutes afterwards. The quality of anaesthesia was assessed according to Steward's scale. The investigation lasted between 50 and 100 min in all three groups. There were no significant differences in haemodynamic and respiratory parameters during the investigation between the groups. Recovery was shorter and of better quality in group E1. On the opposite, 30 minutes after the end of the catheterization, all the patients in group K3 were stuporous, with 5 of them displaying involuntary movements. The patients of the other two groups reacted correctly to stimuli, but those in group G2 went back to sleep very rapidly. There were no complications.(ABSTRACT TRUNCATED AT 250 WORDS)     

Propofol versus etomidate in short-time urologic surgery]

Thirty patients, scheduled for short urological surgical procedures and ranked ASA 1 or 2, were randomly assigned to two homogenous groups. In group P, they were given a 2 mg.kg-1 bolus of propofol and 10 micrograms.kg-1 of alfentanil, followed by a continuous infusion of propofol (5 mg.kg-1.h-1) and 5 micrograms.kg-1 doses of alfentanil. In group E, they were given a 0.3 mg.kg-1 bolus of etomidate, followed by an infusion (1.5 mg.kg-1.h-1). The doses of alfentanil were the same as in group P. Further doses of either propofol (0.5 mg.kg-1) or etomidate (0.2 mg.kg-1) were used should anaesthesia prove not to be deep enough. The patients were not intubated, and breathed spontaneously. Surgery lasted a mean of 18.3 +/- 11.8 min (group P) and 18.8 +/- 9.4 min (group E). The following parameters were studied: the amount of each agent required for maintenance of anaesthesia, the duration of apnoea at induction, the quality of anaesthesia and of muscle relaxation, adverse effects (coughing, trismus, restlessness, nausea, vomiting), the time required for recovery, and its quality. In group P, there was a 27% decrease in arterial pressure, without any tachycardia or hypoxia, together with a quick recovery of excellent quality. On the other hand, in group E, there was little or no haemodynamic alteration, but there often was a trismus at induction. Hypoxia also occurred during induction with etomidate, being severe enough in one case to require tracheal intubation and artificial ventilation. The reasons for this hypoxia seemed to be the apnoea and the trismus, which tends to hinder assisted ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Randomized comparison of outcome after propofol-nitrous oxide or enflurane-nitrous oxide anaesthesia in operations of long duration

A randomized, prospective, comparative study was performed to evaluate induction characteristics, haemodynamic changes and recovery in 60 ASA I-II patients undergoing mainly gynaecological laparotomies with either propofol or thiopentone-enflurane anaesthesia. The propofol group (n = 30) received 2 mg.kg-1 propofol for induction of anaesthesia followed by propofol infusion. The thiopentone-enflurane group (n = 30) received thiopentone 4 mg.kg-1 for induction followed by enflurane (0.5-2 per cent). All patients received nitrous oxide (66 per cent] in oxygen begun one minute after tracheal intubation, and fentanyl (1.5 micrograms.kg-1) four minutes prior to induction. Other drugs administered during or after anaesthesia were similar among the groups. Haemodynamic measurements were similar between propofol and enflurane groups except after tracheal intubation when the mean arterial pressure was lower in the propofol group (P less than 0.05). The propofol group had significantly less (P less than 0.01) emesis in the recovery room than the enflurane group. The propofol group experienced significantly less (P less than 0.05) dizziness, depression/sadness and hunger than the enflurane group in the postoperative period as assessed with a visual analogue questionnaire. We conclude that propofol provided better outcome than enflurane in terms of these nonvital but annoying outcome measures after relatively long intra-abdominal operations.     

The effects of speed of injection on induction with propofol A comparison with etomidate

One hundred and eighty female patients received either propofol 2.5 mg/kg or etomidate 0.3 mg/kg injected over 20, 40 or 80 seconds for induction of anaesthesia after premedication with temazepam 20 mg. The mean induction times for both etomidate and propofol were significantly reduced with increasing speed of injection. The mean induction times for etomidate were significantly less than propofol at the slower rates of injection. At each speed of injection, the decrease in systolic, mean and diastolic arterial blood pressures with etomidate were less than with propofol. The decrease in systolic blood pressure was not significantly affected by injection speed for either drug. Apnoea occurred significantly more frequently with propofol than with etomidate at each speed of injection and the incidence of apnoea greater than 60 seconds with propofol was significantly higher when injected over 20 seconds than 80 seconds. The incidence of pain on injection was unaffected by injection speed for either drug. The incidence of myoclonus and (or) hypertonus was significantly higher following etomidate.     

Comparison of the effects of fentanyl on respiratory mechanics under propofol or thiopental anaesthesia

Twenty patients were randomly anaesthetized with either thiopental 5 mg/kg followed by a 15 mg/kg/h continuous infusion, or propofol 2.5 mg/kg followed by a 9 mg/kg/h continuous infusion, paralysed with vecuronium 0.1 mg/kg, intubated and ventilated with nitrous oxide 50% in oxygen. Fifteen minutes after induction, fentanyl 5 micrograms/kg was injected. Inspiratory tracheal pressure (PT), gas flow (V) and volume (V) were continuously measured while the lungs were inflated with a constant inspiratory flow ventilator. Respiratory compliance (Crs) and resistance (Rrs) were calculated from the regression of PT on V. In both groups Crs decreased following anaesthesia. Fentanyl injection elicited an increase in Rrs (from 1.04 +/- 0.70 to 1.63 +/- 0.92 kPa x l-1 x s) and a further decrease in Crs (from 0.55 +/- 0.30 to 0.42 +/- 0.10 l x kPa-1) in the thiopental group but not in the propofol group (Rrs: 1.26 +/- 0.69 to 1.08 +/- 0.44 kPa x l-1 x s, Crs: 0.49 +/- 0.11 to 0.48 +/- 0.13 l x kPa-1). These results suggest that the dose of propofol administered in this study may prevent fentanyl-induced bronchoconstriction.     

Propofol auto-co-induction as an alternative to midazolam co-induction for ambulatory surgery

We propose the use of an intravenous propofol/propofol auto-co-induction technique as an alternative to propofol/midazolam for induction of anaesthesia. We have studied 54 unpremedicated ASA 1 or 2 patients undergoing day-stay anaesthesia for minor orthopaedic surgery. All received 10 micrograms.kg-1 or alfentanil before induction, followed by either midazolam 0.05 mg.kg-1, propofol 0.4 mg.kg-1 or saline, and 2 min later, a propofol infusion at a rate of 50 mg.kg-1.h-1 until loss of eyelash reflex. We compared pre- and postinduction haemodynamic changes, complications at insertion of a laryngeal mask airway and recovery from anaesthesia in the three groups. Both co-induction techniques showed less postinduction hypotension and significant reduction of the total induction dose of propofol when compared to the control group. In the propofol/propofol group there was a decreased incidence of apnoea during induction of anaesthesia. These patients were discharged from hospital 2 h after the end of anaesthesia whereas patients in the midazolam/propofol group were discharged after 2 1/2 h (p < 0.001).     

依托咪酯和异丙酚复合麻醉对腹部手术患者脑氧代谢影响的比较

目的 比较依托咪酯和异丙酚复合麻醉对腹部手术患者脑氧代谢的影响.方法 择期全麻下拟行腹部手术患者36例,ASA Ⅰ或Ⅱ级,随机分为异丙酚复合麻醉组(P组)和依托咪酯复合麻醉组(E组),每组18例.两组均静脉注射咪达唑仑0.08 mg/kg、芬太尼3μg/kg、维库溴铵0.1 mg/kg,P组静脉注射异丙酚1.5 mg/kg、E组静脉注射依托咪酯0.3 mg/kg行麻醉诱导,P组静脉输注异丙酚4～6mg·kg-1·h-1、E组静脉输注依托咪酯0.4～0.7 mg·kg-1·h-1,术中均间断注射维库溴铵和芬太尼维持麻醉.分别于麻醉前(T1)、气管插管后即刻(T2)、手术开始30 min(T3)及术毕即刻(T4)时监测HR、MAP和SpO2,抽取桡动脉血和颈内静脉球部血样行血气分析,测定乳酸浓度,计算动脉血氧含量(CaO2)、颈内静脉氧含量(cjvO2)、脑氧摄取率(CERO2).结果 两组HR、MAP和SpO2均在正常范围内.与T1时相比,两组SaO2、SjvO2、PaO2、PjvO2升高,T2-4时Da-jvO2和CERO2降低(P<0.01);两组问比较各时点SaO2、SjrO2、PaO2、PjvO2、CaO2、CjvO2、Da-jvO2、CERO2及乳酸水平差异均无统计学意义(P>0.05).结论 依托眯酯和异丙酚复合麻醉均可降低腹部手术患者的脑氧代谢率,且无明显差别.     

Etomidate vs. propofol to carry out suspension laryngoscopies

Patients about to undergo a suspension laryngoscopy were randomly assigned to one of two groups (n = 10). They were given either etomidate 1 mg kg-1 followed by 1 mg kg-1 h-1, or propofol 2.5 mg kg-1 followed by 9 mg kg-1 h-1. Alfentanil 10 micrograms kg-1 was given to provide analgesia with a further half dose if necessary. Duration of apnoea, quality of anaesthesia, times between stopping hypnotic administration and the moment when the patients opened their eyes, gave their name, date of birth and the day's date were noted. Heart rate, blood pressures, respiratory frequency and blood gases were noted before induction, before suspension and when hypnotic infusion was stopped. Clinical tolerance was good, the duration of surgery, apnoea and quality of anaesthesia were the same for both groups. Blood pressure was less depressed by etomidate, but ventilatory frequency was higher. Recovery was significantly faster after propofol. Propofol is recommended for patients who require good post-operative cooperation (chronic obstructive pulmonary disease) and etomidate for those who are haemodynamically compromised.     

Intravenous infusion of propofol for induction and maintenance of anaesthesia during endoscopic carbon dioxide laser ENT procedures with high frequency jet ventilation

Fourteen patients of ASA grades 1 3 were anaesthetised with continuous infusions of propofol and alfentanil for endoscopic carbon dioxide laser ENT microsurgery. Their lungs were ventilated with an oxygen-air mixture using a high frequency jet ventilator. Propofol was given at an initial rate of 120 μg/kg/minute for 10 minutes after a bolus dose of 2.6 mg/kg, and then at 80 fig μg/kg/minute. Alfentanil was given at a rate of 0.5 μg/kg/minute. Arterial pressure decreased significantly after the bolus dose. It increased significantly for a few minutes after laryngoscopy and returned to baseline values during maintenance of anaesthesia. Heart rate increased significantly during induction and until laryngoscopy was performed but it decreased below its initial value after 5 minutes of maintenance. Platelet count and the degree of aggregation did not change during infusion of propofol.     

A comparison of the course of anesthesia using a bolus application of propofol, methohexital or etomidate as hypnotics and alfentanil analgesia

The suitability of the analgesic-hypnotic combination alfentanil-propofol in nitrous oxide-oxygen IPPB for short-term and outpatient anesthesia was studied in 50 patients of ASA risk groups I and II. This study appeared pertinent since the two substances have the shortest half-lives of their respective classes of medication. For comparison, two groups of similar size were treated with the well-established combinations alfentanil-methohexital and alfentanil-etomidate. During the entire intra- and postoperative periods the circulatory parameters were frequently monitored as was the continuous recording of the compressed spectral array in the EEG. Thirty minutes after extubation three modified tests of recovery were carried out that were compared to the preoperative results. For a subjective evaluation, a multiple choice questionnaire was answered by each patient after the recovery tests. The mean duration of anaesthesia in all three groups was 1 h. All three combinations were found to be agreeable to the patients with the best results in the propofol group. These patients also showed the most rapid recovery; consequently, the combination of alfentanil and propofol would appear to be especially suitable for outpatients. For the induction of anesthesia alfentanil was administered in a dosage of 30 micrograms/kg body weight in combination with propofol 1.5 mg/kg, methohexital 1.0 mg/kg or etomidate 0.2 mg/kg. For anesthesia maintenance the following mean dosages were found to be suitable: Alfentanil 1 microgram/kg/min, propofol 46 micrograms/kg/min, methohexital 24 micrograms/kg/min, and etomidate 4 micrograms/kg/min.(ABSTRACT TRUNCATED AT 250 WORDS)