A comparison of alfentanil, halothane and enflurane for day-case gynaecological surgery

Sixty patients received either alfentanil, halothane or enflurane for maintenance of anaesthesia during short day-case gynaecological procedures. The alfentanil group recovered more rapidly but there was no difference between halothane and enflurane in terms of recovery time. Apnoea and movement during surgery only occurred in the patients who received alfentanil. The incidence of other side effects was the same in each group, including late subjective feelings of drowsiness and unsteadiness.     

A comparison of alfentanil, halothane and enflurane as supplements for outpatient urological surgery

Seventy-seven patients presenting for outpatient cystoscopy participated in a trial to assess postoperative recovery when either alfentanil, halothane, or enflurane were used in combination with nitrous oxide/oxygen anaesthesia. Anaesthesia was uneventful in all cases. Apnoea occurred once with alfentanil, but naloxone was not required. Vomiting occurred once with alfentanil and once with enflurane. Anti-emetics were not required. Blood pressure and pulse rate variations from preoperative levels occurred with similar frequency in all groups. Times to open eyes, show left thumb, and give correct date of birth were significantly less with alfentanil than with the other agents tested. Trieger testing failed to demonstrate an advantage of alfentanil, although two patients in each of the halothane and enflurane groups were insufficiently recovered to complete the tests. As tested, alfentanil represents a useful alternative to halothane or enflurane as postoperative recovery of mental function is significantly more rapid than with the inhalational agents.     

Comparison of alfentanil,fentanyl and enflurane as supplements to general anaesthesia for outpatient gynaecologic surgery

We compared two narcotic/N2O anaesthetic techniques and an inhalational anaesthesia/N2O technique for outpatient surgery in 59 women undergoing short gynaecological procedures. All patients received droperidol 0.625 mg IV, thiopentone and 70 per cent N2O in O2 plus either alfentanil (15 micrograms.kg-1), fentanyl (1.5 microgram.kg-1) or enflurane. The narcotics were given in a double-blind fashion and all anaesthetic techniques were assigned randomly. Cardiorespiratory parameters remained stable in all groups, with few clinically important changes occurring. Recovery was significantly faster in the group receiving alfentanil, with the time to respond to verbal commands and the time to establish alertness significantly faster than with either fentanyl or enflurane. All techniques provided satisfactory anaesthesia; however, the patients receiving alfentanil had significantly more adverse events than those receiving fentanyl.     

A comparison of anaesthesia using remifentanil combined with either isoflurane, enflurane or propofol in patients undergoing gynaecological laparoscopy, varicose vein or arthroscopic surgery

BACKGROUND: Anaesthesia comprising remifentanil plus isoflurane, enflurane or propofol was randomly evaluated in 285, 285 and 284 patients, respectively, undergoing short-procedure surgery. METHODS: Anaesthesia was induced with propofol (0.5 mg x kg(-1) and 10 mg x 10 s(-1)), and a remifentanil bolus (1 microg x kg(-1)) and infusion at 0.5 microg x g(-1) x min(-1). Five minutes after intubation, remifentanil infusion was halved and 0.5 MAC of isoflurane or enflurane, or propofol at 100 microg x kg(-1) x min(-1) were started and titrated for maintenance. RESULTS: Patient demography and anaesthesia duration were similar between the groups. Surgery was performed as daycases (52%) or inpatients (48%). The median times (5-7 min) to extubation and postoperative recovery were similar between the groups. Responses to tracheal intubation (15% vs 8%) and skin incision (13% vs 7%) were significantly greater in the total intravenous anaesthesia (TIVA) group (P<0.05). Fewer patients given remifentanil and isoflurane (21%) or enflurane (19%) experienced > or =1 intraoperative stress response compared to the TIVA group (28%) (P<0.05). Median times to qualification for and actual recovery room discharge were 0.5-0.6 h and 1.1-1.2 h, respectively. The most common remifentanil-related symptoms were muscle rigidity (6-7%) at induction, hypotension (3-5%) and bradycardia (1-4%) intraoperatively and, shivering (6-7%), nausea and vomiting postoperatively. Nausea (7%) and vomiting (3%) were significantly lower with TIVA compared with inhaled anaesthetic groups (14-15% and 6-8%, respectively; P<0.05). CONCLUSION: Anaesthesia combining remifentanil with volatile hypnotics or TIVA with propofol was effective and well tolerated. Times of extubation, postanaesthesia recovery and recovery room discharge were rapid, consistent and similar for all three regimens.     

A comparison between isoflurane and alfentanil supplemented anaesthesia for short procedures

Sixty unpremedicated patients undergoing short urological and gynaecological procedures were randomly allocated to three groups to receive either methohexitone, alfentanil, nitrous oxide and oxygen, methohexitone, isoflurane and oxygen or methohexitone, isoflurane, nitrous oxide and oxygen. The group receiving methohexitone, isoflurane and oxygen was abandoned after 11 patients had been studied, due to poor conditions during induction of anaesthesia. Therefore, data from only 51 patients are presented. Early recovery was assessed by time to opening eyes, giving correct name and date of birth; later, recovery was assessed by using the postbox test and deletion of 'p's. During anaesthesia and surgery, there was a high incidence of coughing and laryngospasm in the isoflurane groups. The patients in the alfentanil group opened their eyes and gave their names and dates of birth significantly faster postoperatively (p less than 0.01) than those in the isoflurane groups. However, there were no significant differences between the three groups regarding the later tests of recovery. The late recovery after isoflurane was equal to that obtained using an intravenous technique with alfentanil, although the peroperative complication rate was higher.     

Propofol and alfentanil total intravenous anaesthesia: a comparison of techniques for major thoracic surgery

Background : Previous work has highlighted the disadvantages of propofol as a sole agent for total intravenous anaesthesia (TIVA). This randomised study investigated three combinations of propofol and alfentanil as TIVA for major thoracic surgery.
Methods : In 73 patients undergoing elective thoracic surgery, anaesthesia was conducted either with sodium thiopentone induction and inhalational maintenance (incorporating isoflurane) or with TIVA using propofol with alfentanil (by infusion at one of two rates or in incremental doses). Vital signs and recovery characteristics were recorded.
Results : There were no significant differences in heart rate or blood pressure between groups during either induction or maintenance. Depth of anaesthesia was controlled satisfactorily in all groups. Recovery characteristics were similar between treatment groups, although there was a trend towards earlier orientation
Conclusion : Continuous infusions of propofol and alfentanil provide safe and reliable TIVA for major thoracic surgery. TIVA was found to be a satisfactory technique in more elderly patients than previously described. The higher of the two alfentanil infusion rates may result in a better combination of propofol and alfentanil with respect to recovery times than the lower.     

Clinical experience with alfentanil for induction of anaesthesia; a comparison with thiopentone

Alfentanil, a new short-acting narcotic was clinically evaluated as an intravenous anaesthetic induction agent in 19 patients and compared to 20 patients receiving thiopentone. Alfentanil was superior to thiopentone in cardiovascular stability, both during induction of anaesthesia and tracheal intubation. However, alfentanil does not behave like a typical induction agent, time to unconsciousness is longer and more variable and is often accompanied by muscle rigidity. The results of this study suggest that alfentanil is more difficult to use as an induction agent than thiopentone, but alfentanil is recommended for short procedures when haemodynamic stability is important.     

A comparison of the incidence and nature of cardiac dysrhythmias occurring during enflurane and isoflurane anaesthesia for dental surgery

The incidence and nature of dysrhythmias with equipotent concentrations of enflurane and isoflurane during dental surgery were compared. Seventy-six Chinese patients between 17-30 years, of ASA Grade I, randomly received either enflurane or isoflurane with N2O and O2 for spontaneous ventilation during third molar extractions. The cardiac rhythm and the blood pressure were continuously monitored during the procedure. The incidence of dysrhythmias with both enflurane and isoflurane was low and the difference not statistically significant. During surgery one patient exhibited unifocal ventricular ectopics with isoflurane. Sinus tachycardia was common with both agents. No life-threatening dysrhythmias were seen with either agent and no clinically significant lowering of blood pressure occurred in association with the exhibited dysrhythmias. In this Chinese population, as in other studies, the incidence of dysrhythmias with both agents was low thus showing no difference between the races.     

Myocardial metabolism and haemodynamic responses with enflurane anaesthesia for coronary artery surgery

Ten patients were studied before, during and after enflurane anaesthesia for coronary vein grafting. All had good ventricular function and nine were receiving effective beta blockade. Cardiac output and vascular pressures were measured, plus coronary sinus blood flow (CBF), myocardial oxygen consumption (MVO2) and lactate extraction (MLE). Enflurane induction (10 minutes, mean 1.72 per cent end tidal) reduced blood pressure (MAP), due to decreased cardiac index (CI), with no change in heart rate or systemic resistance. Intubation returned MAP and CI to control level but the heart rate increased. Subsequently, enflurane kept MAP, CI and stroke work below the awake level. CBF decreased on induction, rose again on intubation and remained normal before bypass. MVO2 fell on induction from an increase in CS oxygen content, which remained elevated. Normal MLE continued in every patient. There was no evidence of myocardial ischaemia in patients on beta blockade, when haemodynamics were maintained at or below those of the sedated, awake state.     

Intravenous anaesthesia for cystoscopy: a comparison of propofol or methohexitone with alfentanil

Sixty out-patients undergoing cystoscopy were allocated randomly into two groups. No premedication was given. Induction of anaesthesia was preceded by intravenous alfentanil 7 micrograms kg-1 given over 20 s, followed by methohexitone 1.5-2 mg kg-1 or propofol 2 mg kg-1, given over 20 s. Anaesthesia was maintained by increments of alfentanil, methohexitone or propofol, given as required.     

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.     

Out-patient laparoscopy in general anaesthesia with alfentanil and atracurium A comparison with fentanyl and pancuronium

The effects of the new intravenous anaesthetic drugs alfentanil (50 micrograms/kg) and atracurium (0.5 mg/kg) on per- and post-operative function in out-patients clinics were compared with fentanyl (5 micrograms/kg) and pancuronium (0.07 mg/kg). Sixty-two healthy female patients submitted for out-patient sterilization by laparoscopy participated in the study. Thirty patients receiving alfentanil and atracurium (the AA-group) had significantly less pain during analgetic injection, less coughing during intubation, and faster and more pronounced muscle relaxation during induction of anaesthesia, compared with 32 patients receiving fentanyl and pancuronium (the FP-group). The AA-group had less adrenocortical stress-response judged by systolic blood pressure and pulse rate during anaesthesia. Reversal of anaesthesia and neuromuscular blockade were performed without differences in awakening parameters between the two groups. The AA-group had a significantly better score on P-deletion test 45 min after reversal of anaesthesia, a better street fitness score in the afternoon after the procedure and a better day-life function score at home in the evening. There was no difference between the groups in postoperative complaints and in function after the day of operation.     

The independent metabolic effects of enflurane anaesthesia and surgery

The metabolic effects of enflurane anaesthesia (1MAC) in air/oxygen were investigated in six healthy unpremedicated women scheduled for total abdominal hysterectomy (TAH). The changes in acid-base status, CO2 production, and circulating concentration of total protein, albumin and a variety of metabolites (glucose, lactate, glycerol and alanine) were measured before and during a 2-h period of anaesthesia alone, during 1 h of anaesthesia plus surgery, and in the recovery period. The subjects were maintained normothermic (36.5 +/- 0.3 degrees C), and with an arterial SaO2 above 95% throughout the period of study. The circulating concentration of all metabolites changed little as a result of anaesthesia alone, but the glucose and lactate levels rose rapidly after the onset of surgery (P less than 0.05). Plasma albumin and total protein concentration decreased during the study, reaching values that were significantly lower than the pre-anaesthetic values (P less than 0.05). CO2 production decreased by 9% during anaesthesia and surgery, but returned towards preoperative values during recovery. This study provides no evidence of any significant effect of enflurane anaesthesia alone on human intermediary metabolism. Most of the changes in circulating metabolite concentrations observed during and after anaesthesia and surgery are likely to be due to the surgical stress.     

A multicentre trial in spontaneously breathing patients. A comparison of recovery following alfentanil or enflurane

Recovery from anesthesia and the effect of premedication, induction agent and the individual anesthetist on the measure of recovery was assessed in 707 patients scheduled to undergo short surgical procedures. Patients were randomly allocated to receive either alfentanil or enflurane as a supplement to an induction agent, nitrous oxide/oxygen anesthetic technique with or without premedication. Patients who received alfentanil had a faster immediate recovery than those who received enflurane (p less than 0.001). Total anesthetic time was shorter in the alfentanil group (p = 0.02). For 36 of 37 anesthetists recovery was faster in the alfentanil group compared to the enflurane group. Choice of premedication and induction agent had a significant effect on recovery, thiopentone or lorazepam prolonged recovery time in each group. Although the alfentanil group had a higher incidence of apnoea, movement and vomiting (p less than 0.001), the enflurane group had a higher incidence of coughing (p less than 0.001) and shivering (p = 0.004). Overall the anesthetists assessed the alfentanil technique as excellent or good in more patients than the enflurane technique.     

A comparison of enflurane and propofol in thoracic surgery

Comparisons between propofol and inhalational anesthetics for maintenance of anesthesia are limited. The purpose of our prospective study was to examine differences between enflurane and propofol during pulmonary resections with one-lung ventilation (1LV). METHOD. 28 patients, ASA risk group II-III, gave written informed consent for inclusion in this institutionally approved study. The patients were randomly allocated to one of the following groups: A: propofol 10 mg kg-1 h-1, B: 1 MAC enflurane, for maintenance of anesthesia. In both groups analgesia was achieved by fentanyl and muscle relaxation, by pancuronium. Ventilation via a double-lumen tube was controlled (FiO2 = 1.0, PaCO2 35-40 mmHg). Measurements, including hemodynamics and arterial and mixed venous blood gases, were obtained before induction (I), during two-lung ventilation (2LV) 15 min after induction in the supine position (II) and 20 min after surgical opening of the chest in the lateral decubitus position (III), 20 min after starting 1LV (IV), and after extubation (V). RESULTS. No significant differences between the two groups were found before induction (I), during 2LV (II, III), or after extubation (V). The only significant differences between the two groups were observed during 1LV (IV): the shunt fraction was 33.9 +/- 2.5% in A and 38.5 +/- 2.6% in B (P less than or equal to 0.05). Hypoxic pulmonary vasoconstriction was not inhibited in A, but was inhibited by 21.5% in group B during 1LV. Since no case of hypoxemia occurred in group A during 1LV (range of PaO2: 75.2-417.0 mmHg), but four patients developed hypoxemia in group B (Range of PaO2: 46.6-431.0 mmHg), regimen A might be of value in high-risk patients during thoracic surgery when 1LV is planned.