Induction of anesthesia using propofol in comparison with etomidate

Etomidate and propofol were compared for induction of anesthesia in a controlled study, including 24 male patients (ASA groups I and II). Following oral premedication with lormetazepam, the patients received propofol (2.5 mg kg-1; n = 12) or etomidate (0.3 mg kg-1; n = 12) over 60 s. For statistical analysis of the cardiovascular data (blood pressure and heart rate) four blocks were set up: A, baseline value including atropine dosage; B, value after induction of anesthesia; C, value after administration of halothane and vecuronium before intubation; D, value after intubation. The blood pressure fell slightly on administration of propofol while the heart rate remained nearly unchanged. Etomidate was associated with unacceptably high increases in blood pressure and heart rate. Myoclonia occurred in seven patients after etomidate and in two patients after propofol. A smoother mask ventilation was rated as a further advantage of propofol. Because of the unfavorable cardiovascular profile, the occurrence of myoclonia and poor mask ventilation, etomidate proved to be unsuitable for induction of anesthesia unless supplemented by an opioid and/or benzodiazepine. The high incidence of pain upon injection was considered to be a disadvantage of propofol.     

A cost comparison of methohexital and propofol for ambulatory anesthesia.

Methohexital is eliminated more rapidly than thiopental, and early recovery compares favorably with propofol. We designed this study to evaluate the recovery profile when methohexital was used as an alternative to propofol for the induction of anesthesia before either sevoflurane or desflurane in combination with nitrous oxide. One hundred twenty patients were assigned randomly to one of four anesthetic groups: (I) methohexital-desflurane, (II) methohexital-sevoflurane, (III) propofol-desflurane, or (IV) propofol-sevoflurane. Recovery times after the anesthetic drugs, as well as the perioperative side effect profiles, were similar in all four groups. A cost-minimization analysis revealed that methohexital was less costly for the induction of anesthesia. At the fresh gas flow rates used during this study, the costs of the volatile anesthetics for maintenance of anesthesia did not differ among the four groups. However, at low flow rates (< or = 1 L/min), the methohexital-desflurane group would have been the least expensive anesthetic technique. In conclusion, methohexital is a cost-effective alternative to propofol for the induction of anesthesia in the ambulatory setting. At low fresh gas flow rates, the methohexital-desflurane combination was the most cost-effective for the induction and maintenance of general anesthesia. Implications: Using methohexital as an alternative to propofol for the induction of anesthesia for ambulatory surgery seems to reduce drug costs. When fresh gas flow rates < or = 1 L/min are used, the combination of methohexital for the induction and desflurane for maintenance may be the most cost-effective general anesthetic technique for ambulatory surgery.     

Patient-controlled drug administration during local anesthesia: A comparison of midazolam, propofol, and alfentanil

Study Objective: To evaluate the perioperative effects of alfentanil, midazolam, and propofol when administered using a patient-controlled analgesia (PCA) device during local anesthesia.

Design: Randomized, single-blind comparative study.

Setting: Outpatient surgery center at a university teaching hospital.

Patients: Ninety outpatients undergoing minor elective surgical procedures with local anesthetic infiltration were assigned to one of three treatment groups.

Interventions: After premedication with midazolam 1 mg intravenously (IV) and fentanyl 50 μg IV, patients were allowed to self-administer 2 ml bolus doses of either alfentanil 250 μg/ml, midazolam 0.4 mg/ml, or propofol 10 mg/ml at minimal intervals of 3 minutes to supplement a basal infusion rate of 5 ml/hr.

Measurements and Main Results: The total intraoperative dosages of alfentanil, midazolam, and propofol were 2.7 ± 1.1 mg, 4.7 ± 2.7 mg, and 114 ± 42 mg, respectively, for procedures lasting 48 ± 28 minutes to 51 ± 19 minutes (means ± SD). Propofol produced more pain on injection (39% vs. 4% and 6% in the alfentanil and midazolam groups, respectively). Episodes of arterial oxygen saturation less than 90% were more frequent with alfentanil (28%) than with midazolam (3%) or propofol (13%). Using the visual analog scale, patients reported comparable levels of discomfort, anxiety, and sedation during the operation in all three treatment groups. Postoperative picture recall was significantly decreased with midazolam versus alfentanil and propofol. Finally, postoperative nausea was reported more frequently in the alfentanil group (29%) than in the midazolam (10%) or propofol (18%) groups, contributing to a significant prolongation of the discharge time in the alfentanil-treated patients.

Conclusions: When self-administered as adjuvants during local anesthesia using a PCA delivery system, alfentanil, midazolam, and propofol were equally acceptable to patients. However, propofol and midazolam were associated with fewer perioperative complications than was alfentanil.     

Continuous intravenous propofol with nitrous oxide for ocular surgery. A comparison with etomidate, alfentanil, nitrous oxide and isoflurane.

Propofol, administered intravenously for induction and as a continuous maintenance anaesthetic with nitrous oxide, was compared, in a group of elderly patients scheduled for ophthalmic surgery, with an anaesthetic technique (etomidate, alfentanil, nitrous oxide and isoflurane) specifically chosen to be haemodynamically stable and evanescent in action. Both techniques resulted in similar effects on blood pressure after induction, intubation and surgical incision, but propofol did not prevent increases in heart rate as effectively at these times. Furthermore, during maintenance anaesthesia, cardiovascular stability and anaesthetic depth were more easily achieved in the group where etomidate, alfentanil and isoflurane were used. Propofol decreased intra-ocular pressure after intubation, while in both groups recovery was rapid with no significant complications. A subgroup of patients receiving alpha-methyldopa had significantly longer post-anaesthetic recovery times.     

A comparison of patient-controlled analgesia fentanyl and alfentanil for labour analgesia

PURPOSE: To determine the analgesic efficacy of equipotent doses of PCA (patient-controlled analgesia) fentanyl and PCA alfentanil for labour pain. METHODS: Twenty three, ASA I - II parturients between 32-42 wk gestational age in whom epidural analgesia was contraindicated were randomized to receive PCA fentanyl (Group F)or alfentanil (Group A). Plain numbered vials contained 21 ml fentanyl 50 microg x ml(-1) or alfentanil 500 microg x ml(-1). A one millilitre loading dose was administered. The PCA solution was prepared by diluting 10 ml study drug with 40 ml saline and the PCA pump was programmed to deliver a dose of 2 ml, delay of five minutes and a basal rate of 2 ml x hr(-1). Maternal measurements obtained were hourly drug dose, total dose, Visual Analog Pain Score (VAPS) q 30 min, sedation score q 1 hr and side effects. Neonates were assessed by 1,5, and 10-min Apgar scores, umbilical venous and arterial blood gases and neurobehavioural scores at four and 24 hr. RESULTS: Mean VAPS from 7 - 10 cm cervical dilatation were higher in Group A than in Group F (85.7+/-13.9 vs. 64.6+/-12.1; P<0.01) There were no inter-group differences in VAPS from 1-3 cm, or from 4-6 cm dilatation, in maternal sedation scores or side effects, or in neonatal outcomes. CONCLUSION: In the doses prescribed in this study, PCA fentanyl was found to provide more effective analgesia in late first stage labour than PCA alfentanil.     

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.     

Comparative hemodynamic study of anesthesia induction with propofol (Diprivan), thiopental, methohexital, etomidate and midazolam in patients with coronary disease

In patients undergoing cardiac surgery, the induction of anesthesia is not without risk because of specific cardiovascular effects of the anesthetic and the preoperative state of the patient. The hemodynamic effects of etomidate, midazolam, thiopental, and methohexital are well known: etomidate is an anesthetic that induces only minor cardiovascular changes; its influence on the endocrine system, however, has reduced its clinical indication. Barbiturates such as thiopental and methohexital produce negative inotropic effects in combination with an increase in heart rate and myocardial oxygen consumption; midazolam reduces pre- and afterload in patients with poor left ventricular function. Propofol, a new short-acting induction agent with good anesthetic properties, is said to diminish arterial pressure as well as myocardial oxygen consumption. METHODS: In a randomized study we investigated the hemodynamic effects of intravenous induction with propofol (2 mg/kg body wt.), thiopental (5 mg/kg), methohexital (1 mg/kg), etomidate (0.3 mg/kg), and midazolam (0.15 mg/kg) in 50 patients undergoing coronary artery bypass grafting. All patients were premedicated with flunitrazepam (0.03 mg/kg up to 2 mg) and morphine hydrochloride (0.2 mg/kg up to 15 mg) 100 min before the investigation. After 0.003 mg/kg fentanyl the patients received the induction agent in the above-mentioned dosage within 40 s followed by 0.1 mg/kg pancuronium bromide. Hemodynamic measurements were performed 1, 3, and 5 min after the end of the injection as well as 1 and 5 min after intubation.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of etomidate and thiopental anesthesia for cardioversion

Sixteen ASA class II or III male patients (aged, 52 to 66 years) undergoing elective cardioversion were randomly assigned to receive either thiopental or etomidate according to an observer-blinded, parallel study design. The appropriate drug was administered in 2-mL aliquots every 15 seconds until the patient no longer responded to verbal commands, at which time cardioversion was attempted. The total dose for induction was 0.22 +/- 0.2 mg/kg and 3.2 +/- 0.4 mg/kg for etomidate and thiopental, respectively. The cardiorespiratory data after induction were evaluated for maximal percent change from baseline. The baseline heart rate was 106 +/- 6 beats/min and 98 +/- 8 beats/min for the etomidate and thiopental groups, respectively (mean +/- SEM). The heart rate decreased 5% after induction with etomidate and increased 7% with thiopental (P less than 0.05). The baseline mean arterial pressure (MAP) was 96 +/- 3 mm Hg and 105 +/- 11 mm Hg for the etomidate and thiopental groups, respectively (mean +/- SEM). The MAP decreased 4% with etomidate and 3% with thiopental. Respiratory rate was significantly increased by 22% after etomidate compared with a 22% decrease in respiratory rate with thiopental (P less than 0.05). Seven of eight patients in the thiopental group required only one countershock, whereas four of eight patients in the etomidate group required only one shock. One patient in each group could not be successfully cardioverted. Recovery time and clinical side effects were similar between groups except for mild myoclonus in the etomidate group. Titration to effect of either etomidate or thiopental provided satisfactory anesthesia for elective cardioversion in hemodynamically stable patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Computer simulation of intracranial pressure changes during induction of anesthesia: comparison of thiopental, propofol, and etomidate

We have developed a computer model of cerebrovascular hemodynamics that interacts with a pharmacokinetic drug model. We used this model to examine the effects of various stimuli occurring during anesthesia on cerebral blood flow (CBF) and intracranial pressure (ICP). The model is a seven-compartment constant-volume system. A series of resistances and compliances relate blood and cerebrovascular fluid fluxes to pressure gradients between compartments. Variable arterial-arteriolar resistance (Ra-ar) and arteriolar-capillary resistance (Rar-c) simulate autoregulation and drug effects, respectively. Rar-c is also used to account for the effect of CO2 on the cerebral circulation. A three-compartment pharmacokinetic model predicts concentration-time profiles of intravenous induction agents. The effect-site compartment is included to account for disequilibrium between drug plasma and biophase concentrations. The simulation program is written in VisSim dynamic simulation language for an IBM-compatible personal computer. Using the model, we have predicted ICP responses during induction of anesthesia for a simulated patient with normal as well as elevated ICP. Simulation shows that the induction dose of intravenous anesthetic reduces ICP up to 30% (propofol > thiopental > etomidate). The duration of this effect is limited to less than 5 minutes by rapid drug redistribution and cerebral autoregulation. Subsequent laryngoscopy causes acute intracranial hypertension, exceeding the initial ICP. ICP elevation is more pronounced in a nonautoregulated cerebral circulation. Simulation results are in good agreement with the available experimental data. The presented model allows comparison of various drug administration schedules to control ICP.     

A comparison of midazolam, alfentanil and propofol for sedation in oupatient intraocular surgery

PURPOSE: To determine the ideal sedative regimen for intraocular surgery under peribulbar or retrobulbar block. The addition of alfentanil and or propofol to midazolam was evaluated with regard to hemodynamic variables, respiratory rate, pain, anxiety, sedation, postoperative recovery and patient satisfaction. METHODS: Eighty two patients aged between 50 and 85 were recruited into this prospective, randomised, double blind study. Patients, in four groups, received 0.015 mg x kg(-1) midazolam, 5 microg x kg(-1) alfentanil and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 5 microg x kg(-1) alfentanil or 0.015 mg x kg(-1) midazolam alone. Blood pressure, heart rate, respiratory rate, pain, anxiety and sedation scores were measured. Times to discharge from the Post Anesthesia Care Unit (PACU) and Day Surgery Unit (DSU) were documented. A 24 hr telephone interview was carried out to determine patient satisfaction. RESULT: Systolic blood pressure of patients in groups that had received alfentanil was 6% lower than that of patients who had not (P<0.05) at the time of insertion of intraocular block. Patients in the alfentanil groups also had lower respiratory rates during the first 15 min after drug administration, but all patients were given supplemental oxygen therefore oxygen saturation was unaffected. Pain scores of patients who had been given alfentanil were lower during the first postoperative hour than those who had not. CONCLUSION: The addition of alfentanil to midazolam is advantageous in providing sedation for insertion of intraocular block.     

Behavior of the histamine level in induction of anesthesia with propofol and methohexital

In a study of the effect of intravenous anesthetics on plasma histamine levels, propofol and methohexital were administered to patients. Histamine determination was performed using an improved fluometric method specific for imidazole derivatives. As a primary step, the plasma histamine concentration was determined in 60 healthy, fasting probands and used as a comparative value. The mean value obtained from 60 examinations was 0.38 +/- 0.12 ng/ml, the median value was 0.37 ng/ml (Table 1). The next step consisted in determination of plasma histamine values in 20 patients 1 h following premedication with fentanyl. In this group, the mean value was 0.33 +/- 0.11 ng/ml, the median value 0.316 ng/ml (Table 2). In another 20 patients the plasma histamine concentration was determined 1 h following intramuscular injection of 1.4 microgram fentanyl +0.07 mg/kg droperidol (Thalamonal). In this group, the mean value was 0.373 +/- 0.11 ng/ml and the median value was 0.736 ng/ml. Subsequently, the effect of 2.5 mg/kg propofol (Disoprivan) or 1 mg/kg methohexital (Brevimytal) on plasma histamine levels was examined in a randomized, prospective study in 22 patients of ASA class I and II (Table 3, Fig. 2). Two minutes prior to injection of the test substances and 2, 4, 8, and 13 min following injection, plasma histamine levels, blood pressure, and heart rate were examined. In both groups, no changes in plasma histamine levels were observed during the period of examination. Comparison of the individual time columns within a group as well as intergroup comparisons revealed no statistically significant differences in either the t test or the Wilcoxon-Mann-Whitney U test.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of propofol, midazolam, and methohexital for sedation during retrobulbar and peribulbar block.

STUDY OBJECTIVE: To compare the efficacy of propofol, methohexital, and midazalom in providing adequate sedation during administration of retrobulbar block and satisfactory postoperative amnesia. DESIGN: Retrospective chart review over a 4-month period. SETTING: Ambulatory patients in the main operating room of a university-affiliated hospital. PATIENTS: One hundred forty-seven ambulatory patients undergoing ophthalmologic surgery of less than 2 hours' duration under regional anesthesia consisting of retrobulbar or peribulbar block and intravenous (IV) sedation. INTERVENTIONS: One of three drugs--propofol 0.47 +/- 0.06 mg/kg, midazolam 0.02 +/- 0.005 mg/kg, or methohexital 0.45 +/- 0.16 mg/kg--was administered IV. Patients were observed for a minimum of 60 seconds or until adequate sedation was achieved, after which a retrobulbar or peribulbar block was performed. MEASUREMENTS AND MAIN RESULTS: Blood pressure, electrocardiogram, and oxygen saturation were monitored and recorded. Patients were observed for apnea, hiccups, pain on injection, excitement, tremor, grimacing, or verbal response during the block. The requirement for additional sedation intraoperatively was noted. Patients were questioned postoperatively in the ambulatory recovery room for recall of needle insertion or discomfort during the block, as well as about their satisfaction with the overall experience. CONCLUSIONS: Grimacing or verbal response during the retrobulbar or peribulbar block did not predict or correlate with patient recall. Propofol was equal to both midazolam and methohexital in providing adequate sedation and postoperative amnesia but possesses the added advantages of reduced postoperative vomiting, lower intraocular pressure, and earlier return-to-home readiness.     

A multicenter comparison of isoflurane and propofol as adjuncts to remifentanil-based anesthesia

STUDY OBJECTIVE: To compare recovery, hemodynamics, and side effects of remifentanil-based anesthesia with hypnotic concentrations of isoflurane or propofol. DESIGN: Multicenter, prospective, randomized, two-group study. SETTING: 15 university and 5 municipal hospitals. Patients: 249 ASA physical status I, II, and III adult patients scheduled for elective gynecological laparoscopy, varicose vein, or arthroscopic surgery of at least 30 minutes' duration. INTERVENTIONS: Anesthesia was induced in the same manner in both groups: remifentanil-bolus (1 microg/kg), start of remifentanil-infusion (0. 5 microg/kg/min), followed by propofol as needed for induction. Five minutes after intubation, remifentanil was reduced to 0.25 microg/kg/min, and it was combined with either a propofol-infusion (0.1 mg/kg/min) or with isoflurane (0.6 vol% end-tidal) in O(2)/air. Adverse hemodynamic responses of heart rate and systolic blood pressure were recorded and treated according to a predefined protocol. With termination of surgery, anesthetic delivery was discontinued simultaneously without tapering, and recovery times were recorded. MEASUREMENTS AND MAIN RESULTS: No significant differences were observed between the remifentanil-isoflurane or remifentanil-propofol treatment regimens. Recovery times (means +/- SD) were similar for spontaneous ventilation (5.8 +/- 3.2 min vs. 6. 3 +/- 3.7 min), extubation (7.6 +/- 3.5 vs. 8.5 +/- 4.2 min), eye opening (6.8 +/- 3.2 vs. 7.5 +/- 3.8 min), and arrival to the postanesthesia care unit (16.5 +/- 7.0 vs.18.0 +/- 7.2 min). There were no significant differences in adverse hemodynamic responses, postoperative shivering, nausea, or vomiting between the groups. CONCLUSIONS: Emergence after remifentanil-based anesthesia with 0.6 vol% of isoflurane is at least as rapid as with 0.1 mg/kg/min propofol. Both isoflurane and propofol are suitable adjuncts to remifentanil, and the applied dosages are clinically equivalent with respect to emergence and recovery. Therefore, both combinations should be appropriate, particularly in settings in which rapid recovery from anesthesia is desirable, such as fast tracking and/or ambulatory surgery.     

A cost-benefit evaluation of using propofol and alfentanil for a short gynecological procedure

It is well established that the immediate recovery after propofol or alfentanil anesthesia is short. Although the drugs themselves are more expensive than older drugs, a potential for saving costs arises. Concerning the benefits in terms of late recovery, less information is available. With vaginal termination of pregnancy (VTP), anesthesia is supposed to be the major cause of sick-leave. Does propofol and alfentanil anesthesia for VTP reduce sick-leave compared with thiopental and nitrous oxide anesthesia, and do the increased costs of the drugs outweigh the reduced costs of sick-leave? Data were obtained from 39 of 40 patients in ASA class I accepted for VTP and allocated to either propofol and alfentanil anesthesia (PA) or thiopental and nitrous oxide anesthesia (TN). A questionnaire was filled in by the patients at home after regaining full fitness. The number of patients with a sick-leave of 2 days or less in the groups was compared statistically with the number of patients with 3 days or more off work. The economic impact from the reported sick-leave was calculated for each study group, using data from national statistics. The figures were compared with the calculated costs of the drugs. The median number of days of sick-leave was 1 in the PA-group and 2 in the TN-group (range 0–3 and 0–5, respectively). Nineteen of the 20 patients in the PA-group and 13 of the 19 patients in the TN-group needed a short sick-leave period of 2 days or less (one-sided test of proportions, P<0.05). At the time of the study each patient was paid 210 SEK/day from the social insurance system and the mean cost of the drugs was 72 and 15 SEK/patient in the PA- and TN-groups, respectively. Using the mean difference in sick-leave between the groups of 0.8 days/patient (rather than the difference in median values of 1), a net gain of 111 SEK/patient was the result of changing from thiopental-nitrous oxide anesthesia to propofol-alfentanil anesthesia. Although the cost of drugs was higher, costs for the social insurance system and for the individuals themselves were reduced by almost 50%, when using the propofol and alfentanil combination, resulting in an overall benefit corresponding to almost twice the increase in the cost of anesthesia.     

Total intravenous anesthesia using propofol and alfentanil as compared to combined inhalation anesthesia reduces the flow velocity in the middle cerebral artery. A Doppler sonographic study]

Anesthesia for craniotomies should guarantee hemodynamic stability, preservation of cerebral autoregulation, and rapid postoperative recovery of consciousness. Increases in intracranial pressure (ICP) and postoperative respiratory depression should be avoided. Combined anesthesia (KA) with N2O and volatile anesthetics may increase cerebral blood flow (CBF), ICP, and cerebral oxygen consumption. According to recent studies, total intravenous anesthesia (TIVA) with propofol and alfentanil seems to best fulfill the requirements. Using transcranial Doppler sonography (TCD) (TC2-64, EME), we studied the influence of TIVA and KA under normo- and hyperventilation on the blood flow velocity (BFV) and pulsatility of the middle cerebral artery (MCA). METHODS. Two groups of 10 patients each undergoing craniotomy were investigated. Systolic and mean BFV, pulsatility index, mean arterial blood pressure, heart rate, and arterial CO2 tension were measured at four time intervals: (1) preoperatively; (2) 15 min after anesthesia induction under normoventilation, preoperatively; (3) 25 min after anesthesia induction under hyperventilation, preoperatively; and (4) 6 h postoperatively. The patients were premedicated with flunitrazepam 1 mg PO. TIVA was induced with 60 mg propofol, 1 mg alfentanil, and 6 mg vecuronium; simultaneously infusions of propofol (15 mg/min) and alfentanil (0.3 mg/min) were started and were maintained until the dura was completely opened. The infusion rates were then reduced to 6 mg/min propofol until skin suturing and 0.1 mg/min alfentanil until dural suturing was completed. Patients were ventilated with O2/air (fiO2 = 0.5). In the KA group anesthesia was induced with 4-6 mg/kg thiopental, 0.15 mg fentanyl, and 6 mg vecuronium and maintained with boluses of fentanyl, N2O (fiO2 = 0.5), and isoflurane (1.3 MAC). The time course is illustrated in Figs. 1 and 2 and the results are shown in Tables 1 and 2. They were tested using a one-factor analysis of variance and the Kruskal-Wallis range test. RESULTS. There was a significant decrease in systolic and mean BFV combined with an increase in pulsatility index after induction of TIVA, while KA induction effected no significant change in cerebral hemodynamics. The subsequent hyperventilation caused a similar decrease in mean BFV and increase in pulsatility index in both groups. CONCLUSION. Using the assumption that the diameter of the MCA is nearly constant, the reduction in BFV associated with an increase in pulsatility during TIVA is explainable as a decrease in CBF. By having a comparable influence on hemodynamics, the reduction in CBF with increase in cerebral vascular resistance seems to make TIVA the more advantageous anesthesia technique for patients with reduced intracranial compliance.     

The comparison of caudal ketamine,alfentanil and ketamine plus alfentanil administration for postoperative analgesia in children

BACKGROUND: Our aim was to compare the effect of single dose caudal ketamine, alfentanil or a mixture of both drugs in the treatment of pain after hypospadias repair surgery in children. METHODS: The group comprised 109 boys, ASA I-II, aged 1-9 years, who were undergoing hypospadias repair surgery as day cases. The children were randomly divided into three groups for postoperative analgesia: group 1, only alfentanil (20 microg x kg(-10) was given caudally; group 2, ketamine (0.5 mg x kg(-1)) alone; and group 3, alfentanil (20 microg x kg(-1))-ketamine (0.5 mg x kg(-1)) was given caudally. The analgesic effect of caudal block was evaluated using the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and sedation was assessed using a five-point sedation score. The first analgesic requirement time and the number of supplementary analgesics required by each child in a 24-h period were also recorded. RESULTS: No statistical differences were found in demographic characteristics, haemodynamic and respiratory parameters, objective pain scores, postoperative sedation scores and duration of surgery among the groups. The median time to first analgesia was significantly shorter in group 1 than in groups 2 and 3 (P=0.009, P=0.001). Significantly more patients in group 1 required additional postoperative analgesia (paracetamol 15 mg x kg(-1)) compared with groups 2 and 3 (P < 0.001). CONCLUSIONS: Caudal administration of ketamine 0.5 mg.kg-1 with or without alfentanil in children produced satisfactory postoperative analgesia without respiratory depression or other side-effects.     

QT interval of the ECG, heart rate and arterial pressure using propofol, methohexital or midazolam for induction of anaesthesia

The effects of propofol 2 mg/kg, methohexital 2 mg/kg or midazolam 0.3 mg/kg were studied on the QT interval of the ECG corrected by the heart rate (QTc), heart rate and arterial pressure during induction of anaesthesia in 87 ASA class I-(II)-patients. The patients were randomly allocated to one of the three anaesthetic groups. The incidence of the patients with a prolonged QTc interval (= more than 440 ms) ranged from 29 to 41% between the groups. In each group these patients were treated separately. After all anaesthetics, the QTc interval was significantly prolonged in the patients with a normal control QTc interval, whereas in the patients with a prolonged control QTc interval, it tended to be shortened both after propofol and methohexital and it was significantly shortened after midazolam. After injection of suxamethonium, no significant QTc interval changes occurred in the patients with a normal control QTc interval in either the propofol or the methohexital groups, whereas in the patients with a prolonged control QTc interval treated with propofol the QTc interval decreased significantly 60 s after suxamethonium when compared with the corresponding preceding values. The mean values in the propofol group in the patients with a normal control QTc interval were always below the upper limit of the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)     

Propofol anesthesia for craniotomy: a double-blind comparison of remifentanil, alfentanil, and fentanyl

For patients undergoing craniotomy, it is desirable to have stable and easily controllable hemodynamics during intense surgical stimulation. However, rapid postoperative recovery is essential to assess neurologic function. Remifentanil, an ultra-short-acting mu-opioid receptor agonist, may be the ideal agent to confer the above characteristics. In this prospective randomized study, we compared the hemodynamic stability, recovery characteristics, and the dose of propofol required for maintaining anesthesia supplemented with an infusion of remifentanil, alfentanil, or fentanyl in 34 patients scheduled for supratentorial craniotomy. With routine monitors in place, anesthesia was induced with propofol (2-3 mg/kg), atracurium (0.5 mg/kg), and either remifentanil (1 microg/kg), alfentanil (10 microg/kg), or fentanyl (2 micro/kg). The lungs were ventilated with O2/air to mild hypocapnia. Anesthesia was maintained with infusions of propofol (50-100 microg/kg/min) and either remifentanil (0.2 microg/kg/min), alfentanil (20 microg/kg/h), or fentanyl (2 microg/kg/h). There were no significant differences among the groups in the dose of propofol maintenance required, heart rate, or mean arterial pressure. However, the time to eye opening (minutes) was significantly shorter in the remifentanil compared to the alfentanil group (6+/-3; 21+/-14; P = 0.0027) but not the fentanyl group (15+/-9). We conclude that remifentanil is an appropriate opioid to use in combination with propofol during anesthesia for supratentorial craniotomy.