The effect of fentanyl on the emergence characteristics after desflurane or sevoflurane anesthesia in children

Desflurane and sevoflurane anesthesia are associated with emergence agitation in children. In this study, we examined the effect of a single intraoperative dose of fentanyl on emergence characteristics in children undergoing adenoidectomy. One hundred children, 2-7 yr old, were randomly assigned to receive desflurane or sevoflurane for maintenance of general anesthesia after an inhaled induction with sevoflurane and a 2.5 microg/kg dose of fentanyl. An observer blind-ed to the anesthetic technique assessed the times to achieve emergence, extubation and recovery criteria, as well as emergence behaviors. The results showed a similar incidence of severe emergence agitation after general anesthesia with desflurane (24%) and sevoflurane (18%). Times to achieve extubation and postanesthesia care unit discharge criteria were shorter with desflurane than with sevoflurane. With this technique, desflurane allows for a more rapid emergence and recovery than sevoflurane. In children receiving desflurane or sevoflurane, the concurrent use of fentanyl in a dose of 2.5 microg/kg results in a small incidence of emergence agitation. IMPLICATIONS: The concurrent use of fentanyl in a dose of 2.5 microg/kg in children receiving desflurane or sevoflurane results in a low incidence of emergence agitation. Desflurane allows for a more rapid emergence and recovery than sevoflurane.     

Premedication with midazolam delays recovery after ambulatory sevoflurane anesthesia in children.

We studied the effect of oral premedication with midazolam on the recovery characteristics of sevoflurane anesthesia in small children. In a randomized, double-blinded study, 60 children (1-3 yr, ASA physical status I or II) undergoing ambulatory adenoidectomy received either midazolam 0.5 mg/kg (Group M) or placebo (Group P) PO approximately 30 min before the induction of anesthesia. All children received atropine 0.01 mg/kg IV and alfentanil 10 microg/kg IV before the induction of anesthesia with sevoflurane up to 8 vol% inspired concentration in N2O 67% in O2. Tracheal intubation was facilitated with mivacurium 0.2 mg/kg. Anesthesia was continued with sevoflurane adjusted to maintain hemodynamic stability. In the postanesthesia care unit, predetermined recovery end points (emergence, recovery, discharge) were recorded. A pain/ discomfort scale was used to determine the quality of recovery. A postoperative questionnaire was used to evaluate the well-being of the patient at home 24 h after surgery. Emergence (spontaneous eye opening), recovery (full points on the modified Aldrete scale), and discharge were achieved later in Group M than in Group P (15+/-6 vs. 11+/-3 min [P = 0.002], 25+/-17 vs. 16+/-6 min [P = 0.01], and 80+/-23 vs. 70+/-23 min [P = 0.03]). Side effects, postanesthetic excitement, and analgesic treatment did not differ significantly between groups. At home, more children in Group P (30%) experienced disturbed sleep during the night compared with those in Group M (4%) (P = 0.007). IMPLICATIONS: In this randomized, double-blinded, placebo-controlled study, premedication with midazolam 0.5 mg/kg PO delayed recovery in children 1-3 yr of age after brief (<30 min) sevoflurane anesthesia. Except for more peaceful sleep at home, premedication did not affect the quality of recovery.     

Rocuronium duration of action under sevoflurane, desflurane or propofol anaesthesia

BACKGROUND AND OBJECTIVE: We conducted a prospective randomized study to evaluate whether the duration of action of a single bolus dose of rocuronium is influenced by maintenance of anaesthesia with sevoflurane, desflurane or propofol infusion. METHODS: Fifty-seven ASA I-II patients undergoing elective abdominal surgery were enrolled in this study. Anaesthesia was induced with thiopental 3-5 mg kg(-1) or propofol 2.5 mg kg(-1) and fentanyl 5 microg kg(-1) and tracheal intubation was facilitated with rocuronium 0.9 mg kg(-1). Thereafter patients were randomly allocated to three different groups to receive sevoflurane, desflurane or propofol for maintenance of anaesthesia. Recovery of neuromuscular function was monitored by single twitch stimulation of the ulnar nerve and by recording the adductor pollicis response using accelerometry. Intergroup recovery times to 5% of control value of single twitch were analysed using analysis of variance with Bonferroni correction. RESULTS: The mean (95% confidence interval) recovery time to 5% of control value of single twitch during desflurane anaesthesia was 90.18 (86.11-94.25) min. Significantly shorter recovery times were observed during sevoflurane or propofol anaesthesia, 58.86 (54.73-62.99) min and 51.11 (45.47-56.74) min, respectively (P < 0.001). There were also significant differences in the recovery time between groups receiving desflurane vs. sevoflurane (P < 0.001) and desflurane vs. propofol (P < 0.001). CONCLUSIONS: Desflurane anaesthesia significantly prolongs the duration of action of rocuronium at 0.9 mg kg(-1) single bolus dose, compared to sevoflurane or propofol anaesthesia maintenance regimens.     

Parental presence during induction enhances the effect of oral midazolam on emergence behavior of children undergoing general anesthesia

Background:  Pre-anesthetic anxiety and emergence agitation are major challenges for anesthesiologists in pediatric anesthesia. Thus, sedative premedication and parental presence during induction of anesthesia (PPIA) are used to treat pre-anesthetic anxiety in children. The aim of the present study was to test if a combination of mother presence and midazolam premedication is effective for improving emergence condition in children undergoing general anesthesia.
Methods:  Sixty children were allocated to one of three groups: a sedative group (0.5 mg/kg oral midazolam), a PPIA group or a sedative and PPIA group. When anesthesia was induced with 7% sevoflurane in 100% oxygen, qualities of mask induction were rated. Anesthesia was maintained with sevoflurane (1.5–2.5%) in 60% oxygen and intravenous fentanyl 4 μg/kg. During emergence from anesthesia, the score of the child's emergence behavior was rated.
Results:  The children in the midazolam group showed a better quality of mask induction compared with those in the PPIA group, the addition of parental presence to oral midazolam did not provide additional improvement of mask induction. In contrast, the children in the midazolam + PPIA group were less agitated than those in the other groups at emergence from anesthesia.
Conclusion:  Parental presence during induction of anesthesia enhanced the effect of oral midazolam on emergence behavior of children undergoing general anesthesia.     

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.     

Use of intranasal fentanyl in children undergoing myringotomy and tube placement during halothane and sevoflurane anesthesia

BACKGROUND: Many children are restless, disoriented, and inconsolable immediately after bilateral myringotomy and tympanosotomy tube placement (BMT). Rapid emergence from sevoflurane anesthesia and postoperative pain may increase emergence agitation. The authors first determined serum fentanyl concentrations in a two-phase study of intranasal fentanyl. The second phase was a prospective, placebo-controlled, double-blind study to determine the efficacy of intranasal fentanyl in reducing emergence agitation after sevoflurane or halothane anesthesia. METHODS: In phase 1, 26 children with American Society of Anesthesiologists (ASA) physical status I or II who were scheduled for BMT received intranasal fentanyl, 2 microg/kg, during a standardized anesthetic. Serum fentanyl concentrations in blood samples drawn at emergence and at postanesthesia care unit (PACU) discharge were determined by radioimmunoassay. In phase 2, 265 children with ASA physical status I or II were randomized to receive sevoflurane or halothane anesthesia along with either intranasal fentanyl (2 microg/kg) or saline. Postoperative agitation, Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores, and satisfaction of PACU nurses and parents with the anesthetic technique were evaluated. RESULTS: In phase 1, the mean fentanyl concentrations at 10 +/- 4 min (mean +/- SD) and 34 +/- 9 min after administering intranasal fentanyl were 0.80 +/- 0.28 and 0.64 +/- 0.25 ng/ml, respectively. In phase 2, the incidence of severe agitation, highest CHEOPS scores, and heart rate in the PACU were decreased with intranasal fentanyl. There were no differences between sevoflurane and halothane in these measures and in times to hospital discharge. The incidence of postoperative vomiting, hypoxemia, and slow respiratory rates were not increased with fentanyl. CONCLUSIONS: Serum fentanyl concentrations after intranasal administration exceed the minimum effective steady state concentration for analgesia in adults. The use of intranasal fentanyl during halothane or sevoflurane anesthesia for BMT is associated with diminished postoperative agitation without an increase in vomiting, hypoxemia, or discharge times.     

Comparison of a combination of midazolam and diazepam and midazolam alone as oral premedication on preanesthetic and emergence condition in children

BACKGROUND: Preanesthetic anxiety and emergence agitation are major challenges for anesthesiologists in pediatric anesthesia. Thus, midazolam has been used as premedication for children. However, midazolam alone is not effective for emergence agitation. The present study tested the effect of a combination of midazolam and diazepam on the preanesthetic condition and emergence behavior in children. METHODS: Forty-two children were allocated to one of three groups: the NoPre group received no premedication; the Mi group received midazolam 0.5 mg kg(-1) orally; and the Mi + Di group received midazolam 0.25 mg kg(-1) and diazepam 0.25 mg kg(-1) orally. When anesthesia was induced with 7% sevoflurane in 100% oxygen, qualities of mask induction and sedation were rated. Anesthesia was maintained with sevoflurane (3-5%) in 100% oxygen. During emergence from anesthesia, the score of the child's emergence behavior was rated. RESULTS: Children in the Mi and Mi + Di groups were more sedated than those in the NoPre group. A combination of midazolam and diazepam provided a better quality of mask induction, when compared with no premedication. Also, the children in the Mi + Di group were less agitated than those in the other groups during the emergence. CONCLUSION: Children in the Mi + Di group were significantly more sedated at induction of anesthesia and less agitated during emergence from anesthesia.     

Oral ketamine premedication can prevent emergence agitation in children after desflurane anaesthesia

BACKGROUND: The purpose of the present study was to determine whether oral ketamine premedication affected the incidence of emergence agitation in children. METHODS: Thirty minutes before induction of anaesthesia, 80 children who were undergoing adenotonsillectomy with or without bilateral myringotomy and insertion of tubes received either ketamine 6 mg.kg(-1) per oral in group K or sour cherry juice alone in group C. Anaesthesia was maintained with desflurane. Emergence and recovery times were recorded. Tramadol was used for postoperative analgesia. Fentanyl (1 microg.kg(-1)) was administered for the treatment of emergence agitation or severe pain that still continued after tramadol administration. Postoperative behaviour was evaluated using a 5-point agitation scale. RESULTS: The incidence of emergence agitation was 56% in group C, and 18% in group K (P = 0.001). There was no significant difference with respect to emergence times except from time to eye opening that was significantly longer in group K (P < 0.0001). CONCLUSION: Oral ketamine premedication reduced the incidence of postanaesthesia emergence agitation in children without delaying recovery.     

The incidence of emergence agitation associated with desflurane anesthesia in children is reduced by fentanyl.

The rapid emergence and recovery from general anesthesia provided by desflurane is associated with a frequent incidence of emergence agitation in children. We sought to determine the mean effective dose of fentanyl that would significantly reduce the incidence of emergence agitation while preserving rapid recovery. Thirty-two children undergoing adenoidectomy received general anesthesia with desflurane and a dose of fentanyl (1.25, 1.87, 2.8, and 4.2 microg/kg) determined by the classic up-down method. Recovery characteristics, including time to extubation, recovery, hospital discharge, agitation, pain, and vomiting, were recorded. Demographics and recovery features were assessed by analysis of variance and Kruskal-Wallis tests. The mean effective dose of fentanyl to reduce agitation was calculated with the Dixon-Massey method to be 2.5 +/- 6.2 microg. There were no significant differences when treatment groups were compared for recovery criteria. Postoperative emesis occurred in 75% of patients. The results of this study demonstrate that a dose of 2.5 microg/kg of fentanyl is sufficient to prevent emergence agitation while preserving the rapid recovery associated with desflurane anesthesia in children undergoing adenoidectomy. Implications: A dose of 2.5 microg/kg of fentanyl prevents emergence agitation associated with desflurane anesthesia in children undergoing adenoidectomy without delaying emergence.     

Desflurane anesthesia after sevoflurane inhaled induction reduces severity of emergence agitation in children undergoing minor ear-nose-throat surgery compared with sevoflurane induction and maintenance

Emergence agitation may occur after general anesthesia with volatile anesthetics in children. We designed this study to examine the emergence behavior of children undergoing ear-nose-throat surgery after sevoflurane induction and desflurane maintenance versus both sevoflurane induction and maintenance using a recently published Pediatric Anesthesia Emergence Delirium (PAED) scale. In 38 premedicated children aged 12 mo to 7 yr mask induction with sevoflurane was performed and they were randomly assigned to receive either sevoflurane (n = 19) or desflurane (n = 19) for maintenance of general anesthesia. Time to tracheal extubation, modified Aldrete score, emergence behavior, recovery complications, and pain scores were assessed. The PAED scale showed a significant advantage for desflurane (6 [0-15] versus 12 [2-20], maximum total score of 20 for severe agitation). Time to extubation was significantly shorter with desflurane than with sevoflurane (5.4 +/- 1.4 versus 13.4 +/- 1.8 min). The modified Aldrete score on arrival in the postanesthesia care unit (PACU) was significantly lower in children receiving sevoflurane for maintenance. Time to discharge from PACU to normal ward and the incidence of adverse effects were not significantly different between the groups. In conclusion, the use of desflurane for maintenance of anesthesia after sevoflurane induction in children is associated with less severe emergence agitation and faster emergence times.     

Desflurane enhances reactivity during the use of the laryngeal mask airway

BACKGROUND: Desflurane and sevoflurane have markedly different pungencies. The tested hypothesis was that patients breathing equivalent concentrations of desflurane or sevoflurane through a laryngeal mask airway (LMA) would have similar responses. METHODS: After institutional review board approval and informed consent were obtained, 60 patients were enrolled and given intravenous midazolam (14 microg/kg) and fentanyl (1 microg/kg) 5 min before induction of anesthesia. The LMA was inserted at loss of consciousness after 2 mg/kg propofol. When spontaneous breathing returned, a randomly assigned volatile anesthetic was started at an inspired concentration of either 1.8% sevoflurane or 6% desflurane at a fresh gas flow of 6 l/min in air:oxygen (50:50). After 5 min, a controlled movement of the LMA took place. Three minutes later, the inspiratory anesthetic concentration was changed to either 3.6% sevoflurane or 12% desflurane for 3 min. A blinded observer recorded movements and airway events during the start of anesthetic, LMA movement, deepening of the anesthetic, and emergence before LMA removal. RESULTS: There were no differences at anesthetic start and LMA movement. Desflurane titration to 12% increased heart rate, increased mean arterial blood pressure, and initiated frequent coughing (53% vs. 0% sevoflurane) and body movements (47% vs. 0% sevoflurane). During emergence, there was a twofold greater incidence of coughing and a fivefold increase in breath holding in the desflurane group. CONCLUSIONS: When airway responses to sevoflurane and desflurane were compared in elective surgical patients breathing through an LMA, there were significantly more adverse responses with desflurane at 12% concentrations and during emergence.     

The effect of epidural bupivacaine on maintenance requirements of sevoflurane evaluated by bispectral index in children

BACKGROUND AND OBJECTIVE: Combined (local and general) anaesthesia or Balanced (intravenous analgesics and inhalational hypnotics) anaesthesia are commonly used in paediatrics. The authors have investigated the influence of both types of anaesthesia on the requirements of sevoflurane to maintain an adequate level of hypnosis as measured by Bispectral index (at around 50) monitoring in paediatric orthopaedic patients. METHODS: Twenty-six orthopaedic surgery patients aged 2-15 yr were randomized to receive, during general sevoflurane anaesthesia, 5 microg kg-1 of intravenous fentanyl (Balanced anaesthesia group) or 1 mL kg-1 of caudal-epidural bupivacaine 0.25% (Combined anaesthesia group). The end-tidal sevoflurane concentration was adjusted every 5 min in order to maintain Bispectral index values at around 50. RESULTS: Patients showed very similar Bispectral index values (P > 0.05) in both the Combined and the Balanced groups before anaesthesia (96.7 +/- 2.7 vs. 96.9 +/- 1.8), after induction (48.5 +/- 2.9 vs. 49.8 +/- 3.6) and after administration of analgesia (50.9 +/- 3.8 vs. 50.3 +/- 4.3). The sevoflurane end-tidal concentration requirements were similar in both the Combined and Balanced groups before administration of analgesia (2.1 +/- 0.2 vs. 2.1 +/- 0.4, P = 0.9415), but lower end-tidal concentrations were required by the Combined group than by the Balanced group (0.81 +/- 0.4 vs. 1.5 +/- 0.5, P < 0.0001) in the first 20 min after administration of analgesia. CONCLUSION: Combined anaesthesia with epidural bupivacaine maintains the same Bispectral index values as Balanced anaesthesia during orthopaedic surgery in children without fentanyl and with a lower sevoflurane requirement.     

Quality of recovery in children: sevoflurane versus propofol

BACKGROUND: Sevoflurane, with its low pungency and low blood and tissue solubility, is an attractive anaesthetic in paediatric outpatient surgery. Propofol-anaesthesia is recognised for its rapid and clear-headed emergence. This study was designed to compare emergence and recovery characteristics of sevoflurane and propofol anaesthesia for tonsillectomy in children. METHODS: Children aged 3-10 years, undergoing elective tonsillectomy, were randomly assigned to receive propofol (n=25, induction with 3 mg x kg(-1), maintenance with 100-250 microg x kg(-1) min(-1)) or sevoflurane anaesthesia (n=25, induction 7 vol.%, maintenance 2-3 vol.%). Tracheal intubation was performed with alfentanil 20 microg x kg(-1) and atracurium 0.5 mg x kg(-1). Ventilation was controlled to maintain normocapnia and all patients received N2O/O2 (60:40 vol.%) for induction and maintenance of anaesthesia. At the end of surgery infiltration of the operative sites with bupivacaine 2 mg x kg(-1) was provided for postoperative analgesia. Emergence, recovery, discharge times, and incidence of side effects were compared between the two groups. RESULTS: Time to extubation (14 vs 15 min), time to response to simple verbal command (21 vs 21 min) and time to discharge from the recovery room (45 vs 50 min) were similar in the sevoflurane and propofol groups, respectively. There was a significantly greater incidence of postoperative agitation in the sevoflurane group (46%) compared with the propofol group (9%) (P=0.008). This did not, however, delay discharge from the recovery room. The incidence of nausea and vomiting was not significantly different (8% vs 0%; P=0.49). CONCLUSION: In children, recovery from anaesthesia with sevoflurane results in a higher incidence of agitation compared with propofol.     

Ondansetron does not modify emergence agitation in children

In this prospective, placebo-controlled study, we evaluated the effect of prophylactic ondansetron therapy on emergence agitation of children who underwent minor surgery below the umbilicus. Seventy children aged one to six years and American Society of Anesthesiologists physical status I were studied. Children were premedicated with midazolam rectally and were randomly assigned to receive either ondansetron (Group O) or placebo (Group P) in combination with caudal anaesthesia. Children in Group O received intravenous ondansetron (0.1 mg/kg for children weighing < 40 kg, 4 mg for children weighing > 40 kg) and Group P (n = 35) received normal saline 2 ml following anaesthesia induction with sevoflurane. Airway management was provided with LMA-Proseal without muscle relaxation and anaesthesia maintenance was provided with a 60:40 N2O:O2 mixture and sevoflurane. Emergence agitation was evaluated with a ten point scale and pain level was assessed every 10 minutes for the first 30 minutes after admission to the recovery room. There were no significant differences between the placebo and ondansetron groups with respect to demographic, anaesthetic and surgical details. Incidences of emergence agitation in ondansetron and placebo groups were similar (32.4% and 30.3% at 10 minutes respectively). Mean modified Children's Hospital of Eastern Ontario pain scale scores and mean ten-point scale scores and emergence agitation incidences decreased similarly after 10 minutes in both groups. Ready time for discharge was similar between the groups. Agitated patients had significantly increased ready time for discharge compared to non-agitated patients (P = 0.001). Prophylactic intravenous ondansetron administration does not reduce emergence agitation comparing to placebo after sevoflurane anaesthesia.     

Epidural lidocaine decreases sevoflurane requirement for adequate depth of anesthesia as measured by the Bispectral Index monitor

BACKGROUND: Epidural anesthesia potentiates sedative drug effects and decreases minimum alveolar concentration (MAC). The authors hypothesized that epidural anesthesia also decreases the general anesthetic requirements for adequate depth of anesthesia as measured by Bispectral Index (BIS). METHODS: After premedication with 0.02 mg/kg midazolam and 1 microg/kg fentanyl, 30 patients aged 20-65 yr were randomized in a double-blinded fashion to receive general anesthesia with either intravenous saline placebo or intravenous lidocaine control (1-mg/kg bolus dose; 25 microg x kg(-1) x min(-1)). A matched group was prospectively assigned to receive epidural lidocaine (15 ml; 2%) with intravenous saline placebo. All patients received 4 mg/kg thiopental and 1 mg/kg rocuronium for tracheal intubation. After 10 min of a predetermined end-tidal sevoflurane concentration, BIS was measured. The ED50 of sevoflurane for each group was determined by up-down methodology based on BIS less than 50 (MAC(BIS50)). Plasma lidocaine concentrations were measured. RESULTS: The MAC(BIS50) of sevoflurane (0.59% end tidal) was significantly decreased with lidocaine epidural anesthesia compared with general anesthesia alone (0.92%) or with intravenous lidocaine (1%; P < 0.0001). Plasma lidocaine concentrations in the intravenous lidocaine group (1.9 microg/ml) were similar to those in the epidural lidocaine group (2.0 microg/ml). CONCLUSIONS: Epidural anesthesia reduced by 34% the sevoflurane required for adequate depth of anesthesia. This effect was not a result of systemic lidocaine absorbtion, but may have been caused by deafferentation by epidural anesthesia or direct rostral spread of local anesthetic within the cerebrospinal fluid. Lower-than-expected concentrations of volatile agents may be sufficient during combined epidural-general anesthesia.     

Bispectral index guided timing of intubation without neuromuscular blockade during sevoflurane induction of anaesthesia in adults

The aim of this study was to assess the effectiveness of bispectral index monitoring (BIS) as a guide to the timing of intubation during sevoflurane induction of anaesthesia without the use of neuromuscular blocking agents in adults, and specifically, whether a target BIS value of 25 provides better intubating conditions than a target BIS of 40. Forty patients were randomized into one of two groups, a target BIS 25 (n =21) or a target BIS 40 (n =19). Patients received premedication with midazolam 20 microg/kg and fentanyl 0.5 microg/kg. Sevoflurane induction of anaesthesia was initiated and titrated to reach the target BIS value and maintained within the target range for two minutes. The trachea was then intubated, with intubating conditions being assessed using a standardized scale. The BIS 25 group had a superior median intubating score of 4 (range 3-9,[IQR 4-5]) vs the BIS 40 group with a median of 7 (5-10, [6-9], P<0.001). The time to reach target BIS values was not statistically different (BIS 25 group 6.6 min, BIS 40 group 5.1 min, P=0.054). End-tidal sevoflurane concentration upon reaching the target BIS was higher in the BIS 25 group (5.3% +/- 1.2%) vs the BIS 40 group (3.5% +/- 0.95) (P<0.001). There was no statistical difference in haemodynamic parameters between groups. A target BIS value of 25 provides good to excellent intubating conditions and better intubating conditions than a target BIS of 40 during sevoflurane induction of anaesthesia without the use of neuromuscular blocking agents.     

Low flow desflurane and sevoflurane anaesthesia in children

BACKGROUND AND OBJECTIVE: Low flow desflurane and sevoflurane anaesthesia were administered to children and compared for haemodynamic response, renal and hepatic function, recovery time and postoperative nausea and vomiting. METHODS: Eighty ASA I-II patients aged 5-15 yr were included in the study. Midazolam was given for premedication. Anaesthesia induction was performed with fentanyl, propofol and atracurium. After intubation, the first group received desflurane, oxygen and nitrous oxide at 6 L min(-1) and the second sevoflurane, oxygen and nitrous oxide at 6L min(-1). Ten minutes after induction the flow was decreased to 1 L min(-1) in both groups. Haemodynamic parameters, preoperative and postoperative renal and hepatic function, the times of operation and anaesthesia, and early recovery data were recorded. Modified Aldrete scores were noted at the 10th and 30th minutes postoperatively and postoperative nausea, and vomiting were assessed. RESULTS: There were no significant differences in haemodynamic parameters, renal and hepatic functions, postoperative recovery and postoperative nausea and vomiting between groups. The recovery time was shorter in the desflurane group compared to the sevoflurane group. CONCLUSION: Low flow desflurane and sevoflurane anaesthesia do not adversely affect haemodynamic parameters, hepatic and renal function in children. Desflurane may be preferred when early recovery from anaesthesia is warranted.     

Prophylactic use of midazolam or propofol at the end of surgery may reduce the incidence of emergence agitation after sevoflurane anaesthesia

Sevoflurane is associated with a high incidence of emergence agitation in children. Midazolam and propofol have been examined with the aim of reducing emergence agitation after sevoflurane anaesthesia. However the effect of both drugs on emergence agitation is still controversial. Therefore we designed this study to measure the effect of midazolam or propofol at the end of surgery on emergence agitation during the recovery period. One hundred and one children, aged one to 13 years, undergoing strabismus surgery were enrolled in this randomised double-blind study. Anaesthesia was induced and maintained with sevoflurane in N2O/O2. Children were randomly assigned to receive midazolam 0.05 mg/kg (group M, n = 35), propofol 1 mg/kg (group P, n = 31) or saline (group S, n = 35). A four-point scale was used to evaluate recovery characteristics upon awakening and during the first hour after emergence from anaesthesia. The incidence of emergence agitation in group M was 42.9% (15/35), in group P 48.4% (15/31) and in group S 74.3% (26/35). The incidence of emergence agitation in groups M and P was significantly less than in group S. The emergence time was prolonged for patients in groups M and P compared to group S. There was no significant difference in the incidence of emergence agitation or in emergence times between the groups P and M. We conclude that propofol or midazolam administration before the end of surgery may be effective in reducing the incidence of emergence agitation in children undergoing strabismus surgery under sevoflurane anaesthesia.     

Emergence and recovery characteristics of desflurane versus sevoflurane in morbidly obese adult surgical patients: a prospective, randomized study

We compared postoperative recovery after desflurane (n = 25) versus sevoflurane (n = 25) anesthesia in morbidly obese adults (body mass index >/=35) who underwent gastrointestinal bypass surgery via an open laparotomy. After premedication with midazolam and metoclopramide 1 h before surgery, epidural catheter placement, induction of anesthesia with fentanyl and propofol, and tracheal intubation facilitated with succinylcholine, anesthesia was maintained with age-adjusted 1 minimum alveolar concentration (MAC) desflurane or sevoflurane. Fentanyl IV, morphine or local anesthetics epidurally, and vasoactive drugs as needed were used to maintain arterial blood pressure at +/-20% of baseline value and to keep bispectral index of the electroencephalogram values between 40 to 60 U. Although patients were anesthetized with desflurane for a longer time (261 +/- 50 min versus 234 +/- 37 min, mean +/- sd; P < 0.05, desflurane versus sevoflurane, respectively) and for more MAC-hours (4.2 +/- 0.9 h versus 3.7 +/- 0.8 h; P < 0.05), significantly earlier recovery of response to command and tracheal extubation occurred in patients given desflurane than in patients given sevoflurane. The modified Aldrete score was greater in desflurane-anesthetized patients on admission to the postanesthesia care unit (PACU) (P = 0.01) but not at discharge (P = 0.47). On admission to PACU, patients given desflurane had higher oxygen saturations (97.0% +/- 2.4%) than patients given sevoflurane (94.8% +/- 4.4%, P = 0.035). Overall, the incidence of postoperative nausea and vomiting and the use of antiemetics did not differ between the two anesthetic groups. We conclude that morbidly obese adult patients who underwent major abdominal surgery in a prospective, randomized study awoke significantly faster after desflurane than after sevoflurane anesthesia and the patients anesthetized with desflurane had higher oxygen saturation on entry to the PACU.     

Diclofenac or paracetamol for analgesia in paediatric myringotomy outpatients

This prospective, randomized, double-blind study compared the analgesic efficacy of oral diclofenac resinate 0.5 mg.kg(-1) with paracetamol 15 mg/kg(-1) for control of postoperative pain in paediatric patients for outpatient bilateral myringotomy and tube insertion. Paracetamol, the most commonly used oral analgesic for paediatric patients, was compared with a new palatable syrup formulation of diclofenac. Sixty-three ASA 1 orA SA 2 children aged one year and above were randomly assigned to receive diclofenac (Group A) or paracetamol (Group B). The study drug was given 30 to 60 minutes before induction of anaesthesia. Anaesthesia was induced with either inhalational sevoflurane or intravenous thiopentone. All subjects received intravenous fentanyl 1 microg/kg(-1) intraoperatively. Postoperative pain was assessed by a blinded observer using the CHEOPS score on eye-opening, and then at 10, 30 and 60 minutes. Children with a CHEOPS score > 7 received further fentanyl 1 microg x kg(-1). The number of cases requiring this "rescue" analgesia was recorded. Both groups were comparable in demographics, induction technique, duration of anaesthesia and time between premedication and induction of anaesthesia. Overall, CHEOPS scores were low for both groups at all times and did not differ between the groups at any time. Twenty per cent of the diclofenac group and 27% of the paracetamol group required rescue analgesia (not statistically significant). The efficacy of diclofenac 0.5 mg x kg(-1) and paracetamol 15 mg x kg(-1) as oral analgesic premedication for BMT was comparable in children receiving an anaesthetic which included intraoperative administration of fentanyl 1 microg x kg(-1).