Evaluation of awakening and recovery characteristics following anaesthesia with nitrous oxide and halothane fentanyl or both for brief outpatient procedures in infants.

This study compared recovery characteristics and postoperative ventilatory function when halothane, fentanyl or combination of halothane and fentanyl in addition to N2O were used for intraoperative anaesthesia in term infants undergoing hernia repair as outpatients. Sixty-six full term ASA PS I infants ages 1-12 months were studied. All received inhalation induction with N2O, O2 and halothane, followed by intravenous atropine and atracurium, tracheal intubation, and controlled ventilation. For anaesthesia maintenance, patients were randomized into one of three groups. Group I received 70% N2O, 30% O2 and halothane. Group II received 70% N2O, 30% O2, halothane and 2 micrograms.kg-1 fentanyl. Group III received 70% N2O, 30% O2 and 10 micrograms.kg-1 fentanyl. Awakening times were similar in all three groups, however, Group I patients had significantly shorter recovery and discharge times than those of Group II and III. None of the patients experienced postoperative apnoea or periodic breathing. One patient in Group III experienced two brief episodes of bradycardia not associated with apnoea or arterial desaturation (SpO2 > 90% for greater than 30 s). Decreased SpO2 occurred less frequently in Group I (5.9%) compared to Group II (22.7%) and Group III (19.0%) patients, however, the group differences were not significant. Transcutaneous CO2 (TcCO2) values were not statistically different among the three groups. Pain scores were initially lower in Groups II and III, but at 120 min the differences were not significant. Postoperative apnoea was not observed in this study. SpO2 < 90% and TcCO2 > 9 kPa (70 mmHg) was more common in infants receiving 2 and 10 micrograms.kg-1 fentanyl than in infants receiving halothane and nitrous oxide anaesthesia. Infants < 3 months old did not have a higher incidence of SpO2 < 90% or significantly higher TcCO2 values when compared to infants > 3 months old. Fentanyl in doses used in this study did not prolong awakening time but did prolong recovery and discharge times in outpatient infants.

Comparison of emergence and recovery characteristics of sevoflurane, desflurane, and halothane in pediatric ambulatory patients.

This study compares the emergence and recovery characteristics of sevoflurane, desflurane, and halothane in children undergoing adenoidectomy with bilateral myringotomy and the insertion of tubes. Eighty children 1-7 yr of age were studied. Thirty minutes prior to the induction of anesthesia, all patients received 0.5 mg/kg midazolam orally. Patients were randomly assigned to one of four groups: Group 1, sevoflurane induction and maintenance (S:S); Group 2, halothane induction and sevoflurane maintenance (H:S); Group 3, halothane induction and maintenance (H:H); or Group 4, halothane induction and desflurane maintenance (H:D). Tracheal intubation was facilitated with the use of a single dose of 0.2 mg/kg mivacurium. A Mapelson D circuit was used, and all patients received N2O:O2 60:40 for induction and maintenance at standardized appropriate fresh gas flow. Ventilation was controlled to maintain normocapnia. End-tidal concentration of anesthetics was maintained at approximately 1.3 minimum alveolar anesthetic concentration (MAC) (halothane: 0.56; sevoflurane: 2.6; desflurane: 8.3) until the end of surgery when all anesthetics were discontinued. Emergence (extubation), recovery (Steward score 6), and discharge times were compared among patients in the four groups using analysis of variance and Newman-Keuls tests P < 0.05 was considered significant. There were no significant differences among the four groups with respect to age, weight, duration of surgery, or duration of anesthesia. Emergence and recovery from anesthesia were significantly faster in the desflurane group (Group 4) compared with the sevoflurane and halothane groups (Groups 1, 2, and 3) (5 +/- 1.6 min vs 11 +/- 3.7, 11 +/- 4.0, 10 +/- 4.0 min and 11 +/- 3.9 min vs 17 +/- 5.5, 19 +/- 7.1, 21 +/- 8.5 min, respectively). There was a significantly greater incidence of postoperative agitation and excitement in patients who received desflurane (55%) versus sevoflurane (10%) and halothane (25%). There were no significant differences among the four groups with respect to the time to meet home discharge criteria (134 +/- 36.9, 129 +/- 53.3, 117 +/- 64.6, 137 +/- 22.6 in Groups 1, 2, 3, and 4, respectively), in the time to drink oral fluids (139 +/- 31.6, 136 +/- 53.8, 123 +/- 65.0, 142 +/- 29.4 min, respectively), or in the incidence of postoperative vomiting. It is concluded that, although desflurane resulted in the fastest early emergence from anesthesia, it was associated with a greater incidence of postoperative agitation. Sevoflurane resulted in similar emergence and recovery compared with halothane. Desflurane and sevoflurane did not result in faster discharge times than halothane in this patient population.

Comparison of sevoflurane and halothane anesthesia in children undergoing outpatient ear, nose, and throat surgery.

STUDY OBJECTIVE: To compare the induction, maintenance, and recovery characteristics of sevoflurane and halothane in pediatric ambulatory patients undergoing adenoidectomy with or without myringotomies (BMTs). To compare the hemodynamic effects of the two drugs. DESIGN: Open, randomized study. SETTING: University-affiliated pediatric hospital. PATIENTS: 39 ASA physical status I children aged 12 months to 12 years undergoing adenoidectomies with or without BMTs. INTERVENTIONS: Patients were randomized to receive sevoflurane or halothane in 60% nitrous oxide (N2O) for induction and maintenance of anesthesia. All patients received midazolam 0.5 mg/kg orally as premedication, as well as fentanyl 1 mcg/kg intravenously (i.v.) immediately following induction. Tracheal intubation was facilitated with mivacurium 0.2 mg/kg i.v. Anesthesia was maintained with an end-tidal concentration corresponding to 1 minimum alveolar concentration (MAC) of each drug until the end of surgery, at which time all anesthetic gases were discontinued simultaneously. Emergence (extubation), recovery (Steward score = 6), and discharge times were compared among patients in both groups. Heart rate (HR) and mean arterial pressure were compared at predetermined intervals. Additional fentanyl was administered after full recovery was documented for an objective pain score of at least 6. MEASUREMENTS AND MAIN RESULTS: Emergence from anesthesia was significantly faster (7.11 +/- 3.05 minutes vs. 9.58 +/- 5.12 minutes) and recovery (19.89 +/- 10.07 minutes vs. 31.08 +/- 9.81 minutes) more rapid in the sevoflurane group. However, there was no difference in the time to meet home discharge criteria (184 +/- 49 minutes vs. 189 +/- 48 minutes). HR was consistently maintained at or above baseline in the sevoflurane group. Blood pressure was significantly more depressed after fentanyl administration in the halothane group. There were no significant differences in the incidence of postoperative vomiting between the two groups. CONCLUSION: Sevoflurane provides a faster anesthetic emergence and recovery than halothane in premedicated patients but it does not expedite meeting current home discharge criteria.

Comparison of propofol and thiopental for rapid anesthesia induction in infants.

We compared the hemodynamic response to laryngoscopy and intubation, as well as emergence and recovery times, when propofol or thiopental were used for rapid intravenous induction of anesthesia in 59 infants undergoing repair of inguinal hernia. An intravenous catheter was inserted under N2O analgesia and atropine 0.01 mg/kg was administered to all patients. Subsequent induction with propofol (3 mg/kg), thiopental (5 mg/kg), or halothane (2%) was followed with succinylcholine (2 mg/kg) and tracheal intubation. Ventilation was manually assisted during surgery, and tracheas were extubated when patients were completely awake. Infants who received propofol showed less hypertensive response to intubation than those who received thiopental or halothane. In the 1- to 6-mo age group, emergence (extubation) time was significantly longer for infants who received thiopental (10.2 +/- 1.4 min) than for those who received propofol or halothane (5.5 +/- 2.5 and 6.2 +/- 1.3 min, respectively). Infants who received thiopental induction had a higher incidence of perioperative airway complications than all others. There was no significant difference in the recovery and discharge times among the three groups. We conclude that when rapid intravenous induction is required for infants, propofol is more effective than thiopental in obtunding the hypertensive response to intubation, and in young infants (1-6 mo) it results in more prompt emergence after short surgical procedures.

Propofol anaesthesia in paediatric ambulatory patients: a comparison with thiopentone and halothane.

The purpose of this study was to evaluate the haemodynamic changes during induction, as well as the speed and quality of recovery when propofol (vs thiopentone and/or halothane) was used for induction and maintenance of anaesthesia in paediatric outpatients. One hundred unmedicated children, 3-12-yr-old, scheduled for ambulatory surgery were studied. The most common surgical procedures performed were eye muscle surgery (42%), plastic surgery (21%), dental restoration (15%), and urological procedures (15%). The children were randomized to an anaesthetic regimen for induction/maintenance as follows: propofol/propofol infusion; propofol/halothane; thiopentone/halothane; halothane for both induction and maintenance. Succinylcholine 1.5 mg.kg-1 was used to facilitate tracheal intubation and N2O/O2 were used as the carrier gases in each case. All maintenance drugs were titrated according to the clinical response of the patient to prevent movement and/or maintain BP +/- 20% of baseline. Two patients (4%) who received propofol expressed discomfort during injection. The mean propofol dose required to prevent movement was 267 +/- 83 micrograms.kg-1.min-1. The overall pattern of haemodynamic changes, as well as awakening (extubation) times were not different among the four groups. Children who received propofol recovered faster (22 vs 29-36 min) (P < 0.05), were discharged home sooner (101 vs 127-144 min) (P < 0.05), and had less postoperative vomiting (4 vs 24-48%) (P < 0.05) than all others.(ABSTRACT TRUNCATED AT 250 WORDS)

Propofol: effective dose and induction characteristics in unpremedicated children.

The induction dose, induction characteristics, and cardiovascular and respiratory effects of propofol were studied in 90 unpremedicated children 3-12 yr old. Propofol in a dose of 1-3 mg.kg-1 was injected in an antecubital vein over 10-30 s. Successful induction was defined by loss of eyelash reflex occurring within 50 s of the conclusion of propofol injection and followed by subsequent acceptance of face mask without excessive movement. The effective dose of propofol resulting in loss of eyelash reflex in 50% (ED50) and 95% (ED95) of children were 1.3 (1.1-1.4) and 2.0 (1.7-2.6) mg.kg-1 (95% confidence interval). The corresponding ED50 and ED95 for a successful induction that included acceptance of face mask were 1.5 (1.3-1.7) and 2.3 (2.1-3.0), respectively. There was a 6.6% incidence of mild to moderate pain on injection and a 12.7% incidence of involuntary movement. Apnea (cessation of breathing greater than 20 s) was seen in 21% of patients. Blood pressure decreased by more than 20% of baseline value in 48% of patients who received halothane (1-3%) after the bolus injection of propofol. It is concluded that propofol is an effective induction agent in children. A dose of 2.5-3.0 mg.kg-1 is recommended to ensure a smooth transition to an inhalational maintenance technique. The use of antecubital veins is associated with a low incidence of pain on injection.

A comparison between bupivacaine instillation versus ilioinguinal/iliohypogastric nerve block for postoperative analgesia following inguinal herniorrhaphy in children.

This study compared the postoperative pain relief provided by simple instillation of bupivacaine into a hernia wound with that provided by ilioinguinal/iliohypogastric (IG/IH) nerve block. Sixty children undergoing inguinal hernia repair under general anesthesia were randomized to receive 0.25 ml/kg of 0.25% bupivacaine for either IG/IH nerve block or up to 0.5 ml/kg of the same solution for instillation nerve blocks. In the postanesthesia care unit (PACU), a trained blinded observer evaluated the patient's level of postoperative pain using a standardized 10-point objective pain scale. Fentanyl 1-2 micrograms/kg was administered intravenously to any child scoring 6 or more points on the pain scale. The difference in pain scores among the two groups were compared. The two groups were not significantly different in age, duration of surgery, or anesthesia. There was no significant difference between patients who received the two treatment modalities in their pain scores, analgesic requirements in the PACU, recovery times, and discharge times. These results demonstrate that the simple instillation of local anesthetics into a wound provides postoperative pain relief following hernia repair, which is as effective as that provided by intraoperative IG/IH nerve block.