Assessment of depth of anesthesia and postoperative respiratory recovery after remifentanil- versus alfentanil-based total intravenous anesthesia in patients undergoing ear-nose-throat surgery

BACKGROUND: The authors investigated whether total intravenous anesthesia (TIVA) with precalculated equipotent infusion schemes for remifentanil and alfentanil would ensure appropriate analgesia and that remifentanil would result in better recovery characteristics. METHODS: Forty consenting patients (classified as American Society of Anesthesiologists physical status I-III) scheduled for microlaryngoscopy were randomized to receive, in a double-blind manner, either remifentanil (loading dose 1 microg/kg; maintenance infusion, 0.25 microg x kg(-1) x min-1) or alfentanil (loading dose, 50 microg/kg; maintenance infusion, 1 microg x kg(-1) x min-1) as the analgesic component of TIVA. They were combined with propofol (loading dose, 2 mg/kg; maintenance infusion, 100 microg x kg(-1) min(-1)). To insure an equal state of anesthesia, the opioids were titrated to maintain heart rate and mean arterial pressure within 20% of baseline, and propofol was titrated to keep the bispectral index (BIS) less than 60. Neuromuscular blockade was achieved with succinylcholine. Drug dosages and the times from cessation of anesthesia to extubation, verbal response, recovery of ventilation, and neuropsychological testing, orientation, and discharge readiness were recorded. RESULTS: Demographics, duration of surgery, and anesthesia were similar between the two groups. Both groups received similar propofol doses. There were no difference in BIS values preoperatively (mean, 96), intraoperatively (mean, 55), and postoperatively (mean, 96). Recovery of BIS and times for verbal response did not differ. At 20, 30, and 40 min after terminating the opioid infusion, the peripheral oxygen saturation and respiratory rate were significantly higher in the remifentanil group compared with the alfentanil group. CONCLUSIONS: When both the hypnotic and analgesic components of a TIVA-based anesthetic are administered in equipotent doses, remifentanil provides a more rapid respiratory recovery, even after brief surgical procedures, compared with alfentanil.     

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.     

Comparison of propofol-alfentanil and propofol-remifentanil anaesthesia in percutaneous nephrolithotripsy

BACKGROUND AND OBJECTIVE: Percutaneous nephrolithotripsy (PCNL) is used for the fragmentation and removal of stones from the renal pelvis and renal calyceal systems. We compared the effects of propofol-alfentanil or propofol-remifentanil anaesthesia on haemodynamics, recovery characteristics and postoperative analgesic requirements during percutaneous nephrolithotripsy. METHODS: Thirty non-premedicated patients were randomly allocated to receive either propofol-alfentanil (Group A) or propofol-remifentanil (Group R). The loading dose of the study drug was administered over 60 s (alfentanil 10 microg kg(-1) or remifentanil 1 microg kg(-1)) followed by a continuous infusion (alfentanil 15 microg kg(-1) h(-1) or remifentanil 0.15 microg kg(-1) min(-1)). Propofol was administered until loss of consciousness and maintained with a continuous infusion of 75 microg kg(-1) min(-1) in both groups. Atracurium was given for endotracheal intubation at a dose of 0.5 mg kg(-1) and maintained with a continuous infusion of 0.4 mg kg(-1) h(-1). Mean arterial pressure heart rate, the total amount of propofol, time of recovery of spontaneous ventilation, extubation and eye opening in response to verbal stimulus and analgesic requirement were recorded. RESULTS: In Group A, mean arterial pressure was higher at the first minute in the prone position, and during skin incision and lithotripsy, and heart rate was higher during skin incision and lithotripsy when compared with Group R (P < 0.05). The total amount of propofol did not differ between groups. Time of recovery of spontaneous ventilation, extubation and eye opening were significantly shorter in Group R than Group A (P < 0.05). CONCLUSIONS: Both propofol-remifentanil and propofol-alfentanil anaesthesia provided stable haemodynamics during percutaneous nephrolithotripsy, whereas propofol-remifentanil allowed earlier extubation.     

Remifentanil provides better protection against noxious stimuli during cardiac surgery than alfentanil

BACKGROUND AND OBJECTIVE: We hypothesized that remifentanil-propofol cardiac anaesthesia, plus administration of pirinitramide (piritramide) upon cessation of the remifentanil infusion, would be associated with a shorter time to tracheal extubation than alfentanil-propofol anaesthesia, without the occurrence of major haemodynamic instability. METHODS: Haemodynamic stability and recovery characteristics of two remifentanil infusion regimens (0.5 microg kg(-1)min(-1); 0.25 microg kg(-1)min(-1)) were therefore compared with an alfentanil infusion regimen (1 microg kg(-1)min(-1)), in combination with target-controlled infusion of propofol, in a randomized blinded trial in 75 coronary artery surgery patients. RESULTS: Pirinitramide provided good postoperative analgesia without prolonging extubation times: median extubation time in minutes after stopping the opioid-sedative drugs was 300 in the higher-dose remifentanil group and 270 in the lower-dose remifentanil group and alfentanil group (P = 0.606). Significant time-by-treatment interactions were seen for systolic arterial pressure (P = 0.015), mean arterial pressure (P = 0.009) and diastolic arterial pressure (P = 0.006). No significant interaction (P = 0.489) and no constant treatment effect were seen for heart rate (P = 0.288). Time effects were highly significant (P < 0.0001) for all haemodynamic variables. Heart rate remained stable in all groups. In the higher-dose remifentanil group, blood pressure was significantly different and lower during surgery and in this group less bolus doses of the opioid-sedative drugs (P = 0.015) had to be given. CONCLUSION: The higher-dose remifentanil infusion provided superior suppression of haemodynamic responses to noxious stimuli with better haemodynamic stability.     

Assessment of Depth of Anesthesia and Postoperative Respiratory Recovery after Remifentanil-versus Alfentanil-based Total Intravenous Anesthesia in Patients Undergoing Ear-Nose-Throat Surgery

Background: The authors investigated whether total intravenous anesthesia (TIVA) with precalculated equipotent infusion schemes for remifentanil and alfentanil would ensure appropriate analgesia and that remifentanil would result in better recovery characteristics.

Methods: Forty consenting patients (classified as American Society of Anesthesiologists physical status I-III) scheduled for microlaryngoscopy were randomized to receive, in a double-blind manner, either remifentanil (loading dose 1 [mu]g/kg; maintenance infusion, 0.25 [mu]g [middle dot] kg-1 [middle dot] min-1) or alfentanil (loading dose, 50 [mu]g/kg; maintenance infusion, 1 [mu]g [middle dot] kg-1 [middle dot] min-1) as the analgesic component of TIVA. They were combined with propofol (loading dose, 2 mg/kg; maintenance infusion, 100 [mu]g [middle dot] kg-1 [middle dot] min-1). To insure an equal state of anesthesia, the opioids were titrated to maintain heart rate and mean arterial pressure within 20% of baseline, and propofol was titrated to keep the bispectral index (BIS) less than 60. Neuromuscular blockade was achieved with succinylcholine. Drug dosages and the times from cessation of anesthesia to extubation, verbal response, recovery of ventilation, and neuropsychological testing, orientation, and discharge readiness were recorded.

Results: Demographics, duration of surgery, and anesthesia were similar between the two groups. Both groups received similar propofol doses. There were no difference in BIS values preoperatively (mean, 96), intraoperatively (mean, 55), and postoperatively (mean, 96). Recovery of BIS and times for verbal response did not differ. At 20, 30, and 40 min after terminating the opioid infusion, the peripheral oxygen saturation and respiratory rate were significantly higher in the remifentanil group compared with the alfentanil group.     

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.     

A comparison of two different doses of ketamine with midazolam and midazolam alone as oral preanaesthetic medication on recovery after sevoflurane anaesthesia in children

BACKGROUND: This investigation prospectively evaluated the effect of oral premedication of two different doses of ketamine with midazolam and midazolam alone on the recovery of children after sevoflurane anaesthesia. METHODS: In a randomized, double-blind study, 79 children (aged 1-8 years, ASA physical status I or II) were assigned to receive one of three premedications in a volume of 0.5 ml x kg(-1): group 1 received midazolam 0.5 mg x kg(-1) (MD); group 2 received midazolam 0.5 mg x kg(-1) with ketamine 1.8 mg x kg(-1) (MK-1); and group 3 received midazolam 0.5 mg x kg(-1) with ketamine 3 mg x kg(-1) (MK-2). The reactions of the children during administration were noted. Anaesthesia was induced by facemask with incremental sevoflurane administration. All children received alfentanil (15 micro g x kg(-1)). Tracheal intubation was facilitated by mivacurium (0.2 mg x kg(-1)). Anaesthesia was maintained with sevoflurane and an additional dose of alfentanil, if necessary. During recovery, the time interval between discontinuation of anaesthesia and arousal (spontaneous ventilation, extubation) were recorded. RESULTS: Emergence (spontaneous ventilation, extubation) and recovery times (discharge, Aldrete score=9) did not differ significantly between groups (P=0.24, P=0.59 and P=0.145, respectively). CONCLUSIONS: The combination of midazolam and ketamine as oral preanaesthetic medication did not significantly affect the recovery time of children after sevoflurane anaesthesia.     

Recovery after total intravenous anaesthesia using combined midazolam/alfentanil infusion and reversal with flumazenil

One of the major problems with total intravenous anaesthesia (TIVA) is postoperative sedation, possibly with respiratory depression. The aim of the present study was to evaluate the recovery characteristics after TIVA using a continuous infusion of a mixture of midazolam and alfentanil with flumazenil reversal before extubation. This method was compared to balanced anaesthesia using midazolam, alfentanil and nitrous oxide without flumazenil reversal. The degree of sedation was measured by reaction time test, Glasgow Coma Scale, cipher copying test and subtraction test. We found significantly faster reaction times postoperatively in the TIVA group (n = 15) compared to the balanced group (n = 13), despite larger doses of both midazolam (median 21 mg versus 9 mg) and alfentanil (median 5.9 mg versus 4.5 mg). The other tests revealed no difference between the groups. One patient became resedated after flumazenil. We conclude that the TIVA technique described here resulted in slightly better recovery characteristics, offering a usable alternative to balanced anaesthesia.     

Propofol as a sole agent for paediatric day care diagnostic ophthalmic procedures: comparison with halothane anaesthesia

BACKGROUND: Our aim was to study the feasibility of total intravenous anaesthesia with propofol in spontaneously breathing children undergoing ophthalmic procedures. METHODS: Fifty-five children (aged 6 months to 5 years) were randomly allocated to receive either propofol bolus (until loss of eyelash reflex) followed by infusion [group P (n=29)] or halothane 3-4% for induction, followed by 1-2% in 70% nitrous oxide and oxygen via face mask [group H (n=28)]. Dose for induction and maintenance, intraoperative adverse events, time to recovery (on an Observer's Assessment of Alertness/Sedation Scale, 5 at each level) and duration of procedure were recorded. All children in both groups, were anaesthetized successfully. RESULTS: 4.0 +/- 0.7 mg x kg(-1) and 5.1 +/- 1.0 mg x kg(-1) of propofol were required for loss of eyelash reflex and tolerance of the ophthalmic speculum, respectively. An infusion rate of 8.3 +/- 1.7 mg x kg(-1) x h(-1) was needed for maintenance of anaesthesia; 3.4 +/- 0.5%, 3.6 +/- 0.4% and 1.4 +/- 0.4% halothane was needed for induction, tolerance of the eye speculum and maintenance of anaesthesia, respectively. Induction and recovery were significantly faster with halothane compared with propofol [induction - 38.3 +/- 6.6 s (group H)/60.9 +/- 15.2 s (group P) (P < 0.001); recovery 12.8 +/- 4.6 min (group H)/27.0 +/- 23.3 min (group P) (P < 0.001)]. Apnoea, coughing and breath-holding were seen only in group H. Group P had significantly higher incidence of involuntary movements (minor degree) (n=6) (P < 0.01). CONCLUSIONS: Propofol is a feasible option for paediatric diagnostic ophthalmic procedures with the advantage over halothane of providing complete access to the eye.     

The combined effect of ketamine and remifentanil infusions as total intravenous anesthesia for scoliosis surgery in children

BACKGROUND: This study was designed to assess the effect of combination of ketamine and remifentanil infusions as total intravenous anesthesia (TIVA) during scoliosis surgery in children. METHODS: Thirty two children, 8-14 yr of age, scheduled for posterior spinal fusion, were randomly allocated into two equal groups to receive either remifentanil infusion in a dose of 0.2 microg/kg/minutes or same dose of remifentanil infusion combined with ketamine infusion in a dose of 1 microg/kg/minutes after induction of general anesthesia. During surgery, hemodynamics, surgical bleeding, and electrophysiology monitors were recorded. After completion of surgery, recovery score, recovery time and rescue analgesia were assessed in post-anesthesia care unit (PACU) for 24 hours. RESULTS: The two groups were similar for age, weight, duration of surgery, and time to extubation. Intraoperative heart rate and arterial blood pressure were significantly decreased in remifentanil group when compated to remifentanil-ketamine group. The surgical bleeding and electrophysiological monitoring were not significantly affected by remifentanil-ketamine combination in second group. Recovery score and recovery time were not significantly increased in remifentanil-ketamine group. First pain scores recordings in arrival to (PACU) were significantly less in remifentanil-ketamine group than remifentanil group and the time passed to first patient controlled analgesia (PCA) demand dose was increased in remifentanil-ketamine group. The first 24 h morphine consumption was 38 +/- 17 and 28 +/- 10 mg (mean +/- SD) in remifentanil and remifentanil-ketamine groups, respectively. CONCLUSIONS: These data demonstrate that during posterior spinal fusion surgery in children, the combination of ketamine and remifentanil infusions as TIVA may provide hemodynamic stability, satisfactory surgical requirements with reliable electrophysiological monitoring and adequate post operative pain relief supplemented by PCA morphine.     

Comparison of hemodynamics,recovery profile,and early postoperative pain control and costs of remifentanil versus alfentanil-based total intravenous anesthesia (TIVA)

STUDY OBJECTIVE: To compare hemodynamics, recovery profiles, early postoperative pain control and costs of total intravenous anesthesia (TIVA) with propofol and remifentanil and propofol and alfentanil. DESIGN: Randomized, double-blind study. SETTING: University hospital. PATIENTS: 40 ASA physical status I and II adult patients scheduled for lumbar discectomy. INTERVENTIONS: Patients were randomly assigned to receive either remifentanil-propofol or alfentanil-propofol. Anesthesia was induced with remifentanil 1 microg kg(-1) or alfentanil 20 microg kg(-1) with propofol 2 mg kg(-1), and maintained with infusions of propofol 150 to 100 microg kg(-1)min(-1) and either remifentanil 0.1 microg kg(-1) min(-1) or alfentanil 0.5 microg kg(-1) min(-1). MEASUREMENTS: Hemodynamic parameters (heart rate and mean arterial pressure), times to awakening, and tracheal extubation were recorded. In the postanesthesia care unit, pain level, frequency of analgesic demand, frequency of postoperative nausea and vomiting (PONV), partial oxygen saturation (SpO2), and respiratory rates were noted. Drug dosages and costs of each technique were determined. MAIN RESULTS: The mean arterial pressure significantly decreased compared to baseline values 1 minute after induction (p < 0.05) in both groups, and it significantly decreased at 5, 15, and 30 minutes perioperatively in the remifentanil group compared to the alfentanil group (p < 0.05). Time of extubation, spontaneous eye opening, and response to verbal command were similar in both groups. Visual analog scale pain scores at 30 minutes and 60 minutes were significantly lower in the alfentanil group than remifentanil group (p < 0.05). At 15, 30, and 60 minutes after terminating the operation oxygen saturation and respiratory rate were significantly higher (p < 0.05) and analgesics were required sooner in the remifentanil group than the alfentanil group (p < 0.05). The frequency of PONV was similar in both groups. The remifentanil-propofol anesthesia was found to be slightly more expensive as compared to the alfentanil based TIVA (33.41 +/- 4.53 vs. 29.97 +/- 4.1 USD) (p < 0.05). CONCLUSIONS: Both remifentanil and alfentanil provided a reasonably rapid and reliable recovery. The remifentanil-based TIVA was associated with high intraoperative cost and early postoperative pain, but it allowed a more rapid respiratory recovery.     

Small doses of remifentanil and alfetanil in continuous total intravenous anesthesia in major abdominal surgery. A double blind comparison

AIM: The purpose of this study was to test the safety and efficacy of small doses of remifentanil and alfentanil in a continuous total intravenous anesthesia technique for patients undergoing major abdominal surgery. METHODS: Sixty patients were enrolled in the study, and received in a double blind fashion either remifentanil (0.1 microg/kg/min) or alfentanil (alfentanil 0.75 microg/kg/min) in association with propofol (12 mg/kg/h at induction; 6-9 mg/kg/h for maintenance) and cisatracurium. Hemodynamic data, hypnosis monitoring data (Bispectral Index Score), ventilatory parameters and settings, drug utilisation were monitored during stress moments and during all the intraoperative period. Patients were evaluated also in the first 6 postoperative hours. RESULTS: Mean amount of propofol for induction (BIS<60) was lower in the remifentanil group than in the alfentanil group. Significantly fewer patients receiving remifentanil responded to intubation in comparison with patients receiving alfentanil in terms of non invasive blood pressure (>30 mmHg) and heart rate variations. Significantly more patients receiving alfentanil had 1 or more responses to surgery. Incidence of hypotension was significantly higher in patients receiving remifentanil. There were no differences between the 2 groups in the times for spontaneous respiration, adequate respiration, adequate responsivness (OAA/s=5) and discharge from the recovery room. Time to extubation resulted slightly shorter (p<0.05) in patients who received remifentanil. CONCLUSIONS: The use of remifentanil and alfentanil in association with propofol, in a continuous infusion total intravenous anesthesia technique, demonstrated to be safe and reliable strategies.     

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.     

Total intravenous anesthesia with remifentanil, propofol and cisatracurium in end-stage renal failure

PURPOSE: To compare recovery parameters of total intravenous anesthesia (TIVA) with remifentanil and propofol, hemodynamic responses to perioperative events, and pharmacodynamic parameters of cisatracurium in 22 end-stage renal failure and 22 normal renal function patients. METHODS: Anesthesia was induced with 2-3 mg x kg(-1) propofol and 1 microg x kg(-1) remifentanil and maintained with 75 microg x kg(-1) x min(-1) propofol and propofol initial infusion of 0.2 microg x kg(-1) x min(-1) propofol. Arterial pressure and heart rate were maintained by remifentanil infusion rate adjustments. The first twitch (T1) was maintained at 25% by an infusion of cisatracurium. RESULTS: There was no difference in the time to maintenance of adequate respiration, date of birth recollection, first analgesic administration, between the renal failure (4.8+/-2.5, 7.8+/-3.2, 12.3+/-5.3 min respectively) and the control group (5.2+/-2.8, 8.1+/-3.1, 12.7+/-5.5 min): nor were there any differences in the time to 25% T1 recovery, T1 recovery from 25% to 75%, or cisatracurium infusion rate between the renal failure group (32.1 +/-10.8 min, 18.2+/-5.5 min, 0.89+/-0.29 microg x kg(-1) min(-1) respectively) and the control group (35.9 (7.9 min, 18.4+/-3.8 min, 0.95+/-0.22 microg x kg(-1) x min(-1)). CONCLUSION: End-stage renal failure does not prolong recovery from TIVA with remifentanil and propofol, or the recovery from cisatracurium neuromuscular block.     

Remifentanil-propofol versus sufentanil-propofol anaesthesia for supratentorial craniotomy: a randomized trial

BACKGROUND AND OBJECTIVE: Remifentanil has unique pharmacokinetics that might allow faster recovery after neurosurgery. We investigated the effects of a propofol/sufentanil versus a remifentanil/propofol regimen on the primary end-point tracheal extubation time. METHODS: In the Neurosurgery Department of a University Hospital, 36 patients awaiting craniotomy for supratentorial tumour resection were randomly assigned to one of two study groups. In the sufentanil/propofol group, anaesthesia was induced with 0.5 microg kg(-1) sufentanil and 1-2 mg kg(-1) propofol. Propofol infusion and boluses of sufentanil were administered for maintenance. In the remifentanil/propofol group, anaesthesia was started with an infusion of remifentanil (0.2-0.35 microg kg(-1) min(-1)) and a bolus of propofol (1.5-2 mg kg(-1)). Patients received a propofol infusion and a remifentanil infusion for maintenance of anaesthesia. Recovery times were taken from cessation of the propofol infusion. In addition, data about self-reported nausea and vomiting, pain and analgesic requirements were collected. RESULTS: Patients in the remifentanil/propofol group were extubated earlier (mean times 6.4 (+/- SD 4.7) versus 14.3 (+/- 9.2) min; P = 0.003). The two groups were similar with respect to postoperative nausea and vomiting, and patient-reported pain scores. Fifty per cent of the remifentanil/propofol patients and 88% of the sufentanil/propofol patients required no analgesics within 1 h after operation (P = 0.03). CONCLUSIONS: The remifentanil/propofol regimen provided quicker recovery. The two regimens were similar in terms of postoperative nausea and vomiting and patient-reported pain scores, but patients in the remifentanil/ propofol group required more analgesics within 1 h postoperatively.     

Preemptive diclofenac reduces morphine use after remifentanil-based anaesthesia for tonsillectomy

BACKGROUND: We investigated the effect of preincisional rectal diclofenac on pain scores and postoperative morphine requirements of children undergoing tonsillectomy after remifentanil-propofol anaesthesia in a randomized clinical trial. METHODS: Induction and maintenance of anaesthesia were with remifentanil and propofol. Forty children were randomly assigned into two groups before incision. The diclofenac group (n=20) received diclofenac suppositories (approximately 1 mg x kg(-1)) and the control group (n=20) received no treatment. Following discontinuation of remifentanil, patient-controlled analgesia (PCA) with morphine (a loading dose 50 micro g x kg(-1), a background infusion 4 micro g x kg(-1) x h(-1) and a demand dose 20 micro g x kg(-1) with 5-min intervals) was started. We assessed pain score [verbal analogue scales (VAS), 0-10] and sedation level at 5-min intervals and recorded the total morphine consumption of the first hour in the PACU. Patients were discharged to the ward with a new PCA morphine programme (a demand dose 20 micro g.kg-1 with a lockout time of 30 min, for 4 h), and total morphine consumption was recorded. RESULTS: The mean VAS score of the diclofenac group was significantly lower than the control group on arrival in the PACU (2.85 +/- 0.77, 7.60 +/- 0.83, respectively, P < 0.01) and it remained significantly lower in the PACU stay of the children. The mean total morphine consumption of the diclofenac group was less than the control group in the PACU (130.33 +/- 11.26 and 169.92 +/- 9.22, respectively, P=0.012) and the ward (50.80 +/- 11.38 and 87.77 +/- 10.55, respectively, P=0.021). CONCLUSIONS: Preemptive diclofenac given rectally reduced pain intensity and morphine requirements of children anaesthetized with remifentanil for tonsillectomy.     

The effects of remifentanil and alfentanil-based total intravenous anesthesia (TIVA) on the endocrine response to abdominal hysterectomy

STUDY OBJECTIVE: To compare the effects of remifentanil with alfentanil as a part of total intravenous anesthesia (TIVA) on plasma concentrations of cortisol, insulin, and glucose, and hemodynamic responses in patients undergoing abdominal hysterectomy. DESIGN: Randomized, double-blind study. SETTING: University hospital. PATIENTS: 24 ASA physical status I female patients scheduled for abdominal hysterectomy. INTERVENTIONS: Premedicated patients were randomly allocated to receive either remifentanil-propofol (Group R) or alfentanil-propofol (Group A). The loading dose of the study drug was administered over 60 seconds (remifentanil l microg kg(-l) or alfentanil 10 microg kg(-l)) followed by a continuous infusion (remifentanil 0.2 microg kg(-l) min(-l) or alfentanil 0.5 microg kg(-l) min(-l)). In both groups, propofol was administered until loss of consciousness and maintained with a propofol infusion rate of 100 microg kg(-l) min(-l). After induction of anesthesia, all patients were manually ventilated by mask with O2-air mixture for 20 minutes. Then rocuronium 0.6 mg kg(-l) was given for tracheal intubation. MEASUREMENTS: Mean arterial pressure (MAP) and heart rate (HR) were recorded. Plasma concentrations of cortisol, insulin, and glucose were measured during anesthesia and in the recovery room. MAIN RESULTS: In Group R, MAP and HR were lower after tracheal intubation and skin incision than in Group A (p < 0.05). Plasma cortisol concentrations decreased from baseline values at 20 minutes after induction, after tracheal intubation, and skin incision in Group R (p < 0.001). Plasma concentrations of cortisol and glucose increased from baseline values at 30 minutes after skin incision and continued to increase in both groups (p = 0.001). Plasma concentrations of cortisol, insulin, and glucose did not differ between groups at all sampling times. CONCLUSION: Remifentanil provided better hemodynamic stability than alfentanil during anesthesia and surgery. However, both remifentanil and alfentanil had similar effects on the stress endocrine response to abdominal hysterectomy.     

Remifentanil-sevoflurane anaesthesia for laparoscopic cholecystectomy: comparison of three dose regimens

The objective of this study was to determine a dosing regimen for remifentanil-sevoflurane anaesthesia that achieves an optimal balance between quality of anaesthesia and time to recovery. Patients undergoing elective laparoscopic cholecystectomy were randomly allocated to receive 0.4, 0.8 or 1.2 MAC (minimal alveolar concentration) of sevoflurane combined with remifentanil as required to maintain stable anaesthesia. For induction of anaesthesia, the remifentanil dose was 25 microg x kg(-1) x h(-1) and the mean propofol dose which was required to obtain loss of consciousness was 1.59 mg x kg(-1). During the maintenance phase, the mean remifentanil dose was 16.0, 14.1 and 13.0 microg x kg(-1) x h(-1) for the 0.4, 0.8 and 1.2 MAC groups, respectively. The mean sevoflurane maintenance dose was 0.91, 1.24 and 2.1% end-tidal for the 0.4, 0.8 and 1.2 MAC groups, respectively. The incidence of somatic responses was significantly higher in the 0.4 MAC sevoflurane group. Recovery times were significantly faster in the 0.4 compared to the 0.8 and 1.2 MAC groups and in the 0.8 compared to the 1.2 MAC group. The combination of 14 microg x kg(-1) x h(-1) remifentanil and 1.24% end-tidal sevoflurane achieved the optimal balance between the quality, and recovery from anaesthesia.     

Remifentanil versus alfentanil as analgesic adjuncts during placement of ophthalmologic nerve blocks.

BACKGROUND AND OBJECTIVES: Short-acting opioids are often used prior to the placement of ophthalmologic nerve blocks. This study examines whether remifentanil would provide superior analgesia compared with alfentanil, without oversedation or prolonged recovery when given either as a single dose over 30 seconds or as a single dose followed by a continuous infusion, in a dose ratio of 1:7 (remifentanil:alfentanil). METHODS: Seventy-nine ASA I-III patients scheduled for elective ophthalmologic surgery participated in this multicenter, double-blind study. Patients were randomized into three groups: remifentanil (remifentanil 1 microg/kg and placebo infusion); remifentanil infusion (remifentanil 1 microg/kg and infusion of 0.2 microg/kg/min); and alfentanil (alfentanil 7 microg/kg and placebo infusion). Supplemental doses of the respective opioid were given as needed. RESULTS: Seventy-seven percent of patients in the remifentanil group were pain-free at the time of the block placement compared with 44% in the alfentanil group (P < .05). Eighty percent of patients in the remifentanil infusion group were pain-free. Although the occurrence of respiratory depression (14%) was higher in the remifentanil infusion group, it was short-lived (< or = 5 minutes) and resolved spontaneously. More than 89% of patients were awake and alert prior to surgery, and > or = 85% bypassed the phase I recovery area. Nausea and vomiting were rare. CONCLUSIONS: Remifentanil 1 microg/kg results in superior analgesia compared with alfentanil 7 microg/kg when used during the placement of ophthalmologic nerve blocks. The combination of a single dose of remifentanil followed by a continuous infusion was equally effective but resulted in a higher incidence of respiratory depression.     

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.