Comparison of total intravenous anesthesia and sevoflurane-fentanyl anesthesia for outpatient otorhinolaryngeal surgery

STUDY OBJECTIVE: To compare the recovery characteristics of two widely used anesthetic techniques: remifentanyl-propofol and sevoflurane-fentanyl in a standardized ambulatory population.DESIGN: Randomized, single-blinded study. SETTING: University-affiliated medical center. PATIENTS: 50 ASA physical status I and II patients undergoing elective ambulatory otorhinolaryngeal surgery. INTERVENTIONS: Patients were randomized two groups to receive total intravenous anesthesia (TIVA group) with remifentanil and propofol or sevoflurane-fentanyl (SF group). TIVA patients received induction with propofol 1.5 mg/kg intravenously (IV) and remifentanil 0.5 microg/kg IV. The anesthesia was continued with a continuous infusion of propofol 100 microg/kg/min and remifentanil 0.0625-0.25 microg/kg/min. The SF group received, at induction, fentanyl 2 microg/kg followed by propofol 1.5 mg/kg IV. Maintenance was obtained with 1 to 1.5 minimum alveolar concentration of sevoflurane and bolus of fentanyl 1 microg/kg IV as needed. MEASUREMENTS AND MAIN RESULTS: Early recovery times (eye opening, response to commands, extubation, orientation, operating room stay after surgery, and Aldrete score > or =9) and patient satisfaction were similar between the two groups. Postanesthetic discharge scoring system (PADSS) > or = 9 was significantly shorter for the TIVA group (135.9 +/- 51 vs. 103 +/- 32 min) (p < 0.01) but this difference was not associated with a shorter postanesthesia care unit (PACU) length of stay. CONCLUSION: Early recovery times are comparable between total intravenous anesthesia and sevoflurane-based anesthesia. Even though patients in the TIVA group achieved home readiness criteria in a significantly shorter time, this technique does not shorten PACU length of stay, which depends instead on multiple nonmedical and administrative issues.     

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.     

The effect of propofol vs desflurane on recovery from anesthesia with remifentanil in outpatient surgery]

OBJECTIVES: To compare the effect on parameters of postanesthetic recovery of propofol and desflurane administered with high doses of remifentanil for major outpatient surgery. PATIENTS AND METHODS: Seventy patients were randomly assigned to receive propofol (target concentration 1.5-2 microg/ml) or desflurane in perfusion (end expiratory concentration 0.5 MAC) during maintenance of anesthesia with remifentanil (0.25-1 microg/kg/min). The anesthetic agents were withdrawn after surgery. We recorded the times until eye opening, respiration, tracheal extubation, ability to cough, response to verbal orders and orientation. We also recorded the time until a score of 10 on the Aldrete recovery scale was attained, pain on a visual analog scale, sedation on the Ramsay scale, and instances of nausea or vomiting during the first 24 h after surgery. RESULTS: No statistically significant differences in patient characteristics, type of surgery or anesthesia were found. Times until early signs of postanesthetic recovery (eye opening, spontaneous breathing, tracheal extubation) were significantly less (p < 0.05) in the desflurane group. The groups were similar for all other parameters compared (times until ability to cough, respond to verbal orders, orientation and a score of 10 on the Aldrete scale). Duration of stay in the postanesthetic recovery unit, time in the day surgery ward and intensity of postoperative pain were also similar. The rate of postoperative nausea or vomiting was significantly lower in the propofol group. CONCLUSION: During anesthesia with remifentanil, the administration of desflurane is associated with better psychomotor recovery parameters than is propofol, but the rate of nausea and vomiting is higher with desflurane.     

Effects of remifentanil and fentanyl on intraocular pressure during the maintenance and recovery of anaesthesia in patients undergoing non-ophthalmic surgery

BACKGROUND AND OBJECTIVE: To compare the effects of remifentanil and fentanyl on intraocular pressure during the maintenance and recovery of anaesthesia in patients undergoing elective non-ophthalmic surgery. METHODS: Thirty-two patients (ASA I-II) were randomized into two groups to receive either a continuous infusion of remifentanil (0.25-0.5 microg kg(-1) min(-1), n =16, Group R) or an intermittent bolus of fentanyl (2-5 microg kg(-1), n = 16, Group F) during the maintenance of anaesthesia. For the induction of anaesthesia, Group R received remifentanil 1 microg kg(-1) and Group F received fentanyl 2 microg kg(-1); both groups then received propofol 2 mg kg(-1) with vecuronium 0.1 mg kg(-1). Anaesthesia in both groups was maintained with a continuous infusion of propofol 4-8 mg kg(-1) h(-1). Ventilation of the lungs was controlled to a constant end-tidal PCO2 of 4.7-5.4 kPa. Blood pressure, electrocardiography, heart rate and oxygen saturation were monitored throughout anaesthesia. Intraocular pressure was determined before surgery, during the maintenance of anaesthesia, 2 min after emergence and in the recovery room using a Perkins hand-held applanation tonometer by an ophthalmologist blinded to the anaesthetic technique. RESULTS: After induction of anaesthesia, a significant decrease in intraocular pressure in the remifentanil group from 13.6 +/- 2.6 to 7.1 +/- 3.1 mmHg (P < 0.001) and in the fentanyl group from 13.7 +/- 2.2 to 9.7 +/- 3.4 mmHg (P < 0.001) was observed and maintained during anaesthesia. Thirty minutes after the end of anaesthesia, intraocular pressure returned to baseline values in both groups (remifentanil: 13.9 +/- 2.8 mmHg, P = 0.28; fentanyl: 13.6 +/- 2.3 mmHg, P = 0.59). The intraocular pressure and haemodynamic variables did not differ significantly between the two groups (intraocular pressure, P = 0.7327; blood pressure, P = 0.1295; heart rate, P = 0.8601). CONCLUSIONS: Remifentanil maintains intraocular pressure at an equally reduced level compared with fentanyl.     

Remifentanil vs fentanyl with a target controlled propofol infusion in patients undergoing craniotomy for supratentorial lesions

AIM: Remifentanil hydrochloride is an ultra-short acting m-opioid receptor agonist. This study compared the use of remifentanil with that of fentanyl during elective supratentorial craniotomy in a target controlled infusion (TCI)-propofol anesthesia regimen and evaluated the quality of recovery from anesthesia. METHODS: After written informed consent for this prospective study, 40 adult patients were randomly divided into 2 groups: in group F analgesia was provided with fentanyl 2-3 mg kg(-1) h(-1) and in group R with remifentanil 0.25 mg kg(-1) h(-1). Anesthesia was induced with thiopental and pancuronium bromide, and maintained with propofol-TCI, pancuronium, air and oxygen and fentanyl (group F) or remifentanil (group R), respectively. After tracheal intubation, infusion rate of remifentanil was reduced and then adjusted to maintain stable hemodynamics. Hemodynamics and recovery time were monitored for 60 min after surgery. Analgesic requirements, propofol intraoperative consumption, nausea and vomiting in postoperative period were monitored. Recovery was evaluated according to a modified Aldrete score. RESULTS: Baseline hemodynamics were similar in both groups. Mean arterial pressure differed between the 2 groups (P<0.05) with the greatest decrease in group R during dura opening (P<0.001). Postoperative mean arterial pressure was higher in group R. Patients in group R exhibited a faster recovery. The incidence of nausea and vomiting was similar in the 2 groups. Noteworthy, there was a reduction in the amount of propofol used in group R. CONCLUSIONS: Remifentanil appears to be a reasonable alternative to fentanyl during elective surgery of supratentorial lesions.     

Fentanyl or remifentanil to potentiate a single dose of rocuronium in patients anesthetized with propofol with evaluation by accelerometry

OBJECTIVE: To compare the increase in potency of a single dose of rocuronium during anesthesia with propofol combined with either fentanyl or remifentanil. PATIENTS AND METHODS: Forty patients scheduled for plastic surgery were distributed in 2 groups of 20 according to the opioid drug assigned: fentanyl or remifentanil. Induction with propofol was accomplished by computer-controlled infusion, with response measured in the adductor pollicis muscle. After calibration, a dose of 0.6 mg/Kg of rocuronium was infused. Anesthesia was maintained with propofol, oxygen in air, and an equipotent dose of either fentanyl or remifentanil, which was modified to maintain heart rate and systolic arterial pressure within 30% above or below baseline levels. Patient characteristics recorded were age, sex, height, weight, ASA class, type of surgery, and the propofol and opioid doses consumed. Intubation conditions and time to onset of action of rocuronium (T1), of recovery of the first response in a train of four (RT1), and of recovery of 25% of the first response or clinical duration. RESULTS: The groups were statistically similar in terms of demographic variables, type of surgery, propofol and opioid consumption, intubation conditions, and rocuronium T1 and RT1. Clinical duration of anesthesia was longer (p<0.05) in the remifentanil group (33.1 +/- 10 minutes) than in the fentanyl group (27.1 +/- 7.4 minutes). CONCLUSIONS: Remifentanil administered in combination with propofol for anesthesia does not affect time of onset of a single dose of 0.6 mg/Kg dose of rocuronium, but clinical duration of anesthesia is longer with remifentanil and propofol than with the fentanyl and propofol combination. The surgical and intubation conditions achieved with both combinations are adequate and similar.     

Bispectral index-guided administration of anaesthesia: comparison between remifentanil/propofol and remifentanil/isoflurane

BACKGROUND AND OBJECTIVE: The bispectral index of the electroencephalogram is a measure of the hypnotic component of anaesthesia and can be used to guide the administration of anaesthesia. This study compares bispectral index-guided anaesthesia with remifentanil and either propofol or isoflurane. METHODS: Eighty consenting patients were randomly assigned to two groups. Following induction with propofol and remifentanil, anaesthesia was maintained with remifentanil/propofol or remifentanil/isoflurane. Remifentanil infusion rates were guided by haemodynamic responses--maintaining mean arterial pressure and heart rate within 20% of baseline. Propofol and isoflurane administration was guided using the bispectral index (45-60). Thirty minutes before the end of surgery, morphine was administered (0.15 mg kg(-1) intravenously). Fifteen minutes before end of surgery, propofol and isoflurane were reduced (bispectral index 60-75). At the end of surgery, the anaesthetic agents were discontinued. Groups were compared for recovery, remifentanil doses and signs of inadequate anaesthesia using the chi2-test and ANOVA (P < 0.05). RESULTS: The duration of surgery was longer in the propofol/remifentanil group (121 +/- 53 versus 94 +/- 40 min). Recovery data were not different between groups. The remifentanil infusion rate was significantly lower with additional isoflurane (0.18 +/- 0.06 microg kg(-1) min(-1)) than with additional propofol (0.31 +/- 0.20 microg kg(-1) min(-1)). The propofol infusion rate was 123 +/- 48 microg kg(-1) min(-1); isoflurane concentration was 0.66 +/- 0.13%. CONCLUSIONS: Bispectral index-guided anaesthesia with remifentanil plus propofol or isoflurane results in the absence of postoperative recall and a fast recovery with both drug combinations. In our patients, at comparable bispectral index-levels, haemodynamic control requires higher doses of remifentanil with propofol than with isoflurane.     

Remifentanil versus alfentanil in total intravenous anaesthesia for day case surgery

BACKGROUND AND OBJECTIVE: We assessed the intraoperative haemodynamic responses and recovery profiles of total intravenous anaesthesia with remifentanil and alfentanil for outpatient surgery. METHODS: Patients in Group 1 (n = 20) received alfentanil 20 microg kg(-1) followed by 2 microg kg(-1) min(-1) intravenously; patients in Group 2 (n = 20) received remifentanil 1 microg kg(-1) followed by 0.5 microg kg(-1) min(-1) intravenously. Both groups then received propofol 2 mg kg(-1) followed by 9 mg kg(-1) h(-1) intravenously. Five minutes after skin incision, infusion rates were decreased, and at the end of surgery, all infusions were discontinued. Early recovery was assessed by the Aldrete score, whereas intermediate recovery was assessed with the postanaesthetic discharge scoring system (PADS). RESULTS: Perioperative arterial pressure was similar in both groups; heart rate was lower in Group 2 (P < 0.05). The times to spontaneous and adequate respiration, response to verbal commands, extubation and times for Aldrete score > or = 9 were shorter in Group 2 patients (P < 0.05). Pain scores were higher in Group 2 patients (P < 0.05). Overall times for postanaesthetic discharge scores > or = 9 were similar. CONCLUSIONS: Early recovery of patients after day surgery is significantly shorter after total intravenous anaesthesia with remifentanil compared with that with alfentanil but postoperative pain management must be planned ahead.     

Comparison of the effects of remifentanil or fentanyl on anaesthetic induction characteristics of propofol,thiopental or etomidate

BACKGROUND AND OBJECTIVE: This prospective, randomized, double-blinded study was designed to compare the effects of remifentanil or fentanyl on anaesthetic induction characteristics of propofol, thiopental or etomidate. METHODS: Seventy-two patients were enrolled in six groups of 12 individuals each. In three groups, fentanyl was given as a bolus dose of 1.5 microg kg(-1), whereas the others received a remifentanil infusion at 0.5 microg kg(-1) min(-1). Five minutes later, propofol, thiopental or etomidate were titrated to a state of unresponsiveness. Assessment included the amounts of drug necessary for induction, haemodynamics and the times to apnoea, loss of eyelash reflex, and the release of a water-filled syringe held in the patient's hand. RESULTS: Induction times to loss of the eyelash reflex were significantly shorter in the remifentanil than in the fentanyl groups: with propofol 50.7 +/- 13.6s (mean +/- SD) versus 74.9 +/- 27.0s (P < 0.01), with thiopental 42.9 +/- 16.8s versus 77.2 +/- 27.8s (P < 0.01) and with etomidate 54.7 +/- 17.6s versus 72.3 +/- 24.0s (P < 0.05). The times to respiratory arrest or for the syringe to fall were significantly shorter with remifentanil than with fentanyl for propofol and for thiopental, but not for etomidate. In terms of dosages per kg body weight necessary to achieve unresponsiveness, less propofol (-29%, P < 0.05), thiopental (-25%, P < 0.05) or etomidate (-32%, P < 0.01) was necessary with remifentanil than with fentanyl. Haemodynamic responses to tracheal intubation were controlled more effectively with remifentanil. However, within the remifentanil groups, mean arterial pressure significantly decreased during induction: -26% with propofol, -181% with thiopental and -14% with etomidate (all P < 0.01). CONCLUSIONS: During anaesthetic induction, a remifentanil infusion of 0.5 microg kg(-1) min(-1) over 5 min is a suitable alternative to a 1.5 microg kg(-1) bolus dose of fentanyl: induction times are shorter with reduced amounts of propofol, thiopental or etomidate.     

A comparison of remifentanil and fentanyl in patients undergoing carotid endarterectomy

BACKGROUND AND AIM: We investigated the haemodynamic stability and emergence characteristics of isoflurane/nitrous oxide anaesthesia supplemented with remifentanil or fentanyl in patients undergoing carotid endarterectomy. METHODS: Anaesthesia was induced with propofol (1-2 mg kg-1) and either remifentanil (0.5 microgram kg-1) or fentanyl (1 microgram kg-1), followed by an infusion of remifentanil (0.2 microgram kg-1 min-1) or fentanyl (2 micrograms kg-1 h-1). RESULTS: There were no significant differences between the groups in haemodynamic variables, postoperative pain, nausea or vomiting. After induction there was a significant decrease in mean arterial pressure for both groups (P < 0.001) and a decrease in heart rate (P = 0.001) in the remifentanil group. In both groups these haemodynamic changes continued during maintenance of anaesthesia (P < 0.05). The time to eye opening after surgery was significantly shorter with remifentanil compared with fentanyl (6.62 +/- 3.89 vs. 18.0 +/- 15.18 min, P = 0.015). CONCLUSION: Remifentanil appears to be a comparable opioid to fentanyl when supplementing isoflurane/nitrous oxide anaesthesia for carotid endarterectomy.     

Postoperative analgesia after preincisional administration of remifentanil

AIM: The aim of this study was to assess postoperative analgesia after preincisional and postincisional administration of remifentanil. METHODS: Randomized trial, 24 hours. Setting: University hospital, hospitalized care. Patients: 48 adult patients scheduled for lumbar vertebral surgery. Interventions: in group R5, patients received an infusion of 0.2 microg kg(-1) min(-1) remifentanil over 5 minutes, followed by a break of 15 minutes before anesthesia was started. Anesthesia was induced by infusion of 0.25 microg kg(-1) min(-1) remifentanil and a bolus of 1.5 microg kg(-1) propofol, followed by a continuous infusion of 2 to 3 microg kg(-1) h-1 propofol and 0.25 microg kg(-1) min(-1) remifentanil until end of anesthesia. In group R20, patients received 0.05 microg kg(-1) min(-1) remifentanil over 20 minutes before the induction of anesthesia. In group RL, anesthesia was induced and maintained with propofol. After surgery began, a remifentanil infusion of 0.5 microg kg(-1) min(-1) was given for 50 minutes, then reduced to 0.25 microg kg(-1) min(-1). The total remifentanil doses were similar in the 3 groups. Measures: patients used patient-controlled analgesia (piritramide) for postoperative pain management. They recorded pain on a numeric rating scale every half hour. Statistics: Kruskal-Wallis test, pairwise Mann-Withney U-test, orthogonal polynomials (pain scores). RESULTS: Patients given postincisional remifentanil (RL) had the slowest decrease in postoperative pain scores (p<0.01) and the highest cumulative piritramide consumption (p<0.08). CONCLUSION: The preincisional administration of remifentanil followed by a continuous infusion of 0.25 microg kg(-1) min(-1) appears to reduce pain scores and piritramid consumption when compared with a postincisional regimen.     

A randomized double-blinded multicenter comparison of remifentanil versus fentanyl when combined with isoflurane/propofol for early extubation in coronary artery bypass graft surgery

We compared a fentanyl/isoflurane/propofol regimen with a remifentanil/isoflurane/propofol regimen for fast-track cardiac anesthesia in a prospective, randomized, double-blinded study on patients undergoing elective coronary artery bypass graft surgery. Anesthesia was induced with a 1-min infusion of 0.5 mg/kg propofol followed by 10-mg boluses of propofol every 30 s until loss of consciousness. After 0.2 mg/kg cisatracurium, a blinded continuous infusion of remifentanil at 1 microg. kg(-1). min(-1) or the equivalent volume rate of normal saline was then started. In addition, a blinded bolus syringe of 1 microg/kg remifentanil or 10 microg/kg fentanyl, respectively, was given over 3 min. Blinded remifentanil, 1 microg. kg(-1). min(-1) (or the equivalent volume rate of normal saline), together with 0.5% isoflurane, were used to maintain anesthesia. Significantly more patients (P < 0.01) in the fentanyl regimen experienced hypertension during skin incision and maximum sternal spread compared with patients in the remifentanil regimen. There were no differences between the groups in time until extubation, discharge from the surgical intensive care unit, ST segment and other electrocardiogram changes, catecholamine levels, or cardiac enzymes. The remifentanil-based anesthetic (consisting of a bolus followed by a continuous infusion) resulted in significantly less response to surgical stimulation and less need for anesthetic interventions compared with the fentanyl regimen (consisting of an initial bolus, and followed by subsequent boluses only to treat hemodynamic responses) with both drug regimens allowing early extubation. IMPLICATIONS: Both fentanyl and the newer opioid remifentanil, when each is combined with isoflurane and propofol, allowed for fast-track cardiac anesthesia. The remifentanil regimen used in this study resulted in significantly less hemodynamic response to surgical stimulation.     

Target-controlled infusion for remifentanil in vascular patients improves hemodynamics and decreases remifentanil requirement

Remifentanil is a potent ultra-short-acting opioid, which permits rapid emergence. However, remifentanil is expensive and may have detrimental effects on hemodynamics in case of overdose. Target-controlled infusion (TCI) permits adapting infusion to pharmacokinetic models. In this prospective randomized study, we compared intra- and postoperative hemodynamics, remifentanil requirement during anesthesia, and postoperative morphine requirement in patients scheduled for carotid surgery, and receiving either continuous IV weight-adjusted infusion of remifentanil (RIVA) or TCI for remifentanil (TCIR). Forty-six patients were enrolled in this study: all were anesthetized by using TCI for propofol. Twenty-three received RIVA (0.5 micro g. kg(-1) x min(-1)) for the induction of anesthesia and endotracheal intubation, with the infusion rate decreased to 0.25 micro g x kg(-1) x min(-1) after intubation, then adapted by step of 0.05 micro g x kg(-1) x min(-1) according to hemodynamics. Twenty-three patients received TCIR (Minto model, Rugloop), with an effect-site concentration at 4 ng/mL during induction, then adapted by step of 1 ng/mL according to hemodynamics. All patients received atracurium and a 50% mixture of N(2)O/O(2). Hemodynamic variables were recorded each minute. The number and duration of hemodynamic events were collected, and total doses of anesthetics (remifentanil and propofol) and vasoactive drugs were noted in both groups of patients. Data were analyzed by using unpaired t-tests. RIVA was significantly associated with more frequent episodes of intraoperative hypotension (16 versus 6, P < 0.001) and more frequent episodes of postoperative hypertension and/or tachycardia requiring more frequent administration of beta-adrenergic blockers (16 vs 10, P < 0.04) in comparison with TCIR. The need for morphine titration was not significantly different between groups. TCIR led to a significantly smaller requirement of remifentanil (700 +/- 290 versus 1390 +/- 555 micro g, P < 0.001) without difference in propofol requirement. This prospective randomized study demonstrated that, during carotid endarterectomy, in comparison with patients receiving remifentanil using continuous RIVA, TCI results in less hypotensive episodes during the induction of anesthesia, in fewer episodes of tachycardia and/or hypertension and a smaller beta-adrenergic blocker requirement during recovery, and a decrease in remifentanil requirement. Recommendations to prefer TCI for remifentanil administration during carotid endarterectomy may be justified. IMPLICATIONS: Remifentanil for intraoperative analgesia in carotid artery surgery is associated with a better stability in perioperative hemodynamics when administered in target-controlled infusion compared with continuous weight-adjusted infusion. This may be related to a smaller requirement of this drug when using target-controlled infusion, as well as a smooth mode of administration.     

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.     

Midazolam premedication delays recovery from propofol-induced sevoflurane anesthesia in children 1–3 yr

PURPOSE: To study the effect of midazolam premedication on the recovery characteristics of sevoflurane anesthesia induced with propofol in pediatric outpatients. METHODS: Sixty children, one to three years, presenting for ambulatory adenoidectomy were randomly assigned , in a double-blind fashion, to receive either 0.5 mg x kg(-1) midazolam (Group M) or placebo (Group P) p.o. 30 min before anesthesia. Anesthesia was induced with 10 microg x kg(-1) atropine, 10 microg x kg(-1) alfentanil, and 3-4 mg x kg(-1) propofol i.v.. Tracheal intubation was facilitated with 0.2 mg x kg(-1) mivacurium. Anesthesia was maintained with nitrous oxide/oxygen (FiO2 0.3) and sevoflurane with controlled ventilation. Recovery characteristics were compared using the modified Aldrete scoring system, the Pain/Discomfort scale and measuring specific recovery end-points (emergence, full Aldrete score, discharge). A postoperative questionnaire was used to evaluate the children's well-being at home until 24 hr after discharge. RESULTS: Emergence from anesthesia (22 +/- 9 vs 16 +/- 6 min (mean +/- SD), P = 0.005) and achieving full Aldrete scores (30 +/- 11 vs 24 +/- 16 min, P = 0.006) were delayed in patients receiving midazolam. Children in the placebo group were given postoperative analgesia sooner than those in the midazolam group (18 +/- 11 vs 23 +/- 8 min, P = 0.009). More children premedicated with midazolam suffered from arousal distress (20% vs 3%, P = 0.04) and scored higher on the Pain/Discomfort scale (P = 0.004) at 20 min after arrival in the recovery room. Discharge was not affected by premedication and well-being at home was similar in the groups. CONCLUSIONS: Oral premedication with midazolam delays early recovery but not discharge after ambulatory sevoflurane anesthesia induced with propofol in children one to three years. Midazolam did not improve the quality of recovery.     

Hemodynamic stability,myocardial ischemia,and perioperative outcome after carotid surgery with remifentanil/propofol or isoflurane/fentanyl anesthesia

This study compares remifentanil/propofol (remi/prop) with isoflurane/fentanyl (iso/fen) anesthesia to determine which provides the greater hemodynamic stability, lesser myocardial ischemia, and morbidity with better postoperative outcomes after carotid endarterectomy. Sixty patients undergoing unilateral carotid endarterectomy were randomized to receive either a remi/prop or iso/fen anesthetic. Hemodynamic variables were recorded during the surgical procedure. In addition, transesophageal echocardiography was used to assess evidence of intraoperative regional wall motion abnormalities suggestive of cardiac ischemia. Emergence and extubation times, recovery from anesthesia, hemodynamic instability, nausea, vomiting, and pain in post anesthesia recovery, discharge delays, ICU admittance, hospital discharge, and preoperative and postoperative troponin levels were compared using appropriate statistical methods with P < 0.05 considered significant. The groups were demographically alike. Hemodynamic variables were similar during intubation and throughout surgery. Twenty-two percent of patients receiving iso/fen developed intraoperative regional wall motion abnormalities suggestive of ischemia, whereas no remi/prop patients had changes (P < 0.05). There was no difference in ST-T wave changes after surgery, and no patient had an elevation in troponin I levels. Postoperative variables were similar except that patients who received iso/fen had lower Stewart recovery scores during the first 15 minutes after post anesthesia care unit admission and a higher incidence of nausea and vomiting the day after surgery, whereas patients receiving remi/prop had discharge delays secondary to hypertension. ICU admittance, time to first void, oral intake, and time to hospital discharge were similar between the groups. At 9 times the cost of an iso/fen anesthesia technique, remi/prop offers little advantage over inhalational anesthesia for carotid endarterectomy.     

Hemodynamics and emergence profile of remifentanil versus fentanyl prospectively compared in a large population of surgical patients

STUDY OBJECTIVE: To compare the responses to, and hemodynamics associated with surgical stress, recovery profiles, and anesthesiologists' satisfaction following balanced general anesthesia using either remifentanil or fentanyl in a large-scale population. DESIGN: Prospective, 1:1 single blind, randomized, controlled effectiveness study in which patients received either remifentanil or fentanyl in combination with a hypnotic-based anesthesia regimen of either isoflurane or propofol. SETTING: Multicenter study including 156 hospitals and ambulatory surgery facilities. PATIENTS: 2,438 patients (1,496 outpatients and 942 inpatients), 18 years of age or older, scheduled for elective surgeries under general endotracheal anesthesia, with an expected duration of unconsciousness > or =30 minutes. INTERVENTIONS: Patients were randomized to receive either intravenous (IV) remifentanil (0.5 microg/kg/min for induction and intubation, with the infusion rate decreased to 0.25 microg/kg/min after intubation) or IV fentanyl (administered according to anesthesiologists' usual practice) as the opioid during surgery. Concomitant hypnotic drugs were either propofol and/or isoflurane (with or without nitrous oxide) titrated according to protocol. Transition analgesia with either morphine or fentanyl was given to the remifentanil patients and, at the anesthesiologists' discretion, in the fentanyl patients. MEASUREMENTS: Vital signs, adverse events, and emergence profiles were assessed and recorded. Recovery profile was assessed by recording time spent in the postanesthesia care unit and step-down recovery unit, number and timing of adverse events, timing and dosage of rescue medications, and time to eligibility for discharge (to home or to hospital room). Anesthesiologists' satisfaction with the anesthetic regimen was assessed at the end of surgery. MAIN RESULTS: Remifentanil-treated patients exhibited lower systolic and diastolic blood pressures (by 10-15 mmHg) and lower heart rates (by 10-15 bpm) intraoperatively compared to the fentanyl-treated patients. This difference promptly disappeared on emergence. Remifentanil-treated patients responded to verbal command, left the operating room, and (for outpatients) were discharged home sooner than fentanyl-treated patients. Anesthesiologists rated the predictability of response to intraoperative titration, assessment of hemodynamic profiles, and the quality of anesthesia higher in the remifentanil-treated patients. CONCLUSIONS: This study confirms previous observations on the hemodynamic properties associated with remifentanil and extends these to a wider context than previously reported. These characteristics provide clinicians with an alternative in opioid-based anesthesia.     

Postoperative pain management and recovery after remifentanil-based anaesthesia with isoflurane or propofol for major abdominal surgery. Remifentanil Study Group

We have assessed if recovery times after morphine or fentanyl, given before terminating remifentanil anaesthesia with isoflurane or propofol, are compromised. We studied patients undergoing elective, major abdominal surgery, allocated randomly to receive remifentanil and isoflurane (n = 277) or remifentanil and propofol (n = 274) anaesthesia. Twenty-five minutes before the end of surgery, patients received fentanyl 0.15 mg or morphine 15 mg in a randomized, double- blind manner followed by a second dose (fentanyl 0.05 mg, morphine 7 mg) for moderate or severe pain in recovery. Recovery was rapid and at an Aldrete score > or = 9 (median 12-15 min), 42-51% of patients reported none or mild pain. However, 26-35% of patients reported severe pain and > 90% required a second dose of opioid within 21-27 min after anaesthesia.      

Recovery of cognitive function after remifentanil-propofol anesthesia: a comparison with desflurane and sevoflurane anesthesia

We compared the recovery characteristics of remifentanil, desflurane, and sevoflurane when used for anesthesia in elective operative procedures. Sixty ASA physical status I and II patients, aged 18-65 yr, were randomly assigned to receive remifentanil-propofol, desflurane-N2O, or sevoflurane-N2O anesthesia. Before the induction of anesthesia, the patients of the desflurane and sevoflurane groups received fentanyl 2 microg/kg. In all groups, anesthesia was induced with propofol and maintained either with remifentanil 0.25 microg x kg(-1) x min(-1), desflurane, or sevoflurane 0.85 MAC with 65% nitrous oxide in oxygen. Anesthetics were titrated to achieve an adequate level of surgical anesthesia and to maintain mean arterial pressure within 20% of baseline values. Early recovery times and a modified Aldrete Recovery Score > 9 were recorded. Trieger Dot Test and Digit Substitution Test (DSST) were performed the day before surgery and in the postanesthesia care unit to evaluate intermediate recovery. The remifentanil-propofol group had a significantly faster emergence than desflurane or sevoflurane, with no difference between both inhaled anesthetics. Thirty min after anesthesia administration, patients in the remifentanil-propofol and in the desflurane groups gave significantly more correct responses in the DSST compared with sevoflurane (remifentanil 87%, desflurane 83%, sevoflurane 56%), the impairment in the sevoflurane patients corresponding to the effects of a blood alcohol level of approximately 0.1% and, thus, being of clinical importance. Ninety minutes after anesthesia administration, no significant difference could be demonstrated among the groups in the DSST scores. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration. IMPLICATIONS: We compared awakening and intermediate recovery times after remifentanil-propofol anesthesia to desflurane-N2O and sevoflurane-N2O anesthesia. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration.     

Continuous infusion of remifentanil and target-controlled infusion of propofol for patients undergoing cardiac surgery: a new approach for scheduled early extubation

OBJECTIVE: To assess hemodynamic stability, postoperative pain management, and the control and timing of early extubation of a total intravenous anesthetic technique using propofol target-controlled infusion (TCI) and remifentanil in cardiac surgery. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Fifty patients scheduled for elective cardiac surgery. INTERVENTIONS: Premedication consisted of oral midazolam, 0.1 mg/kg. Anesthesia was induced with propofol TCI at a target concentration of 1.5 to 2 microg/mL; remifentanil, 1 microg/kg; and rocuronium. Anesthesia was maintained with propofol at the same target concentration and remifentanil titrated between 0.25 and 1 microg/kg/min. Thirty minutes before the end of surgery, a 0.1-mg/kg bolus of morphine was administered intravenously. Postoperative sedation was achieved by maintaining the propofol infusion until the patient was deemed ready for extubation. Postoperative pain relief was evaluated using a visual analog scale. The intervals between arrival in the intensive care unit, spontaneous ventilation, and extubation were recorded. MEASUREMENTS AND MAIN RESULTS: Included in this study were 36 men and 14 women (American Society of Anesthesiologist = III; New York Heart Association = II) scheduled for cardiac surgery. All patients remained hemodynamically stable throughout the perioperative period. Thirty-seven patients were successfully extubated during the first 4 postoperative hours. Spontaneous breathing was achieved at a mean interval of 15+/-5 minutes after propofol discontinuation. The mean interval to extubation was 163+/-45 minutes after arrival in the intensive care unit. Extubation was performed 48+/-12 minutes after patients were considered ready to awaken. During spontaneous ventilation, 36 patients received additional boluses of morphine (mean, 2.5+/-1 mg). Subsequently, all patients achieved a visual analog scale less than 40 mm. CONCLUSION: The combination of remifentanil and propofol TCI resulted in hemodynamic stability and good postoperative analgesia. This technique allows physicians to schedule the time of extubation in patients undergoing cardiac anesthesia.