ABSTRACT
STUDY OBJECTIVE: To determine, for two different age groups, the effect of duration of sevoflurane administration on the amount of propofol needed when performing tracheal intubation. DESIGN: Classic Dixon's Up-and-Down sequential method. SETTING: University based operating rooms. PATIENTS: 106 ASA physical status 1 and 2 patients aged one to 11 years. INTERVENTIONS: Patients were allocated to the 1-6 year (≥ 12 and < 72 mos) and 6-11 year (≥ 72 and < 132 mos) age groups. Midazolam 0.5 mg/kg was given orally to the 1-6 year group, and all patients were induced with 8% dialed sevoflurane and 67% nitrous oxide (N2O), with N2O discontinued and sevoflurane dialed to 5% after one minute and 1.5 minutes for the younger and older age groups, respectively. Intravenous access was obtained and propofol was promptly administered. Propofol dose was determined according to age group and whether propofol was given 2-4, 4-6, or 6-8 minutes after the start of sevoflurane induction, with Dixon's Up and Down Method used separately for each specific age/time group. Tracheal intubation conditions one minute after propofol were evaluated. MEASUREMENTS: Isotonic regression determined propofol ED50 estimates for excellent tracheal intubation conditions, and linear regression determined the effect of propofol dose on change in systolic blood pressure (SBP). MAIN RESULTS: Estimated propofol ED50 doses for 1-6 year olds, with 95% confidence intervals (CIs), were 1.48 mg/kg (0.80, 2.03), 0.00 mg/kg (0.00, 0.38), and 0.07 mg/kg (0.00, 0.68) in the 2-4, 4-6, and 6-8 minute groups, respectively, with estimated differences between the 2-4 minute group versus the 4-6 and 6-8 minute groups being 1.47 mg/kg (95% CI = 1.04, 2.06) and 1.41 mg/kg (95% CI = 0.74, 2.04), respectively. Estimated propofol ED50 doses for 6-11 year olds, with 95% CIs, were 2.35 mg/kg (1.97, 2.45) and 2.33 mg/kg (1.59, 2.45) in the 2-4 and 4-6 minute groups, respectively. Diminutions in SBP at one minute and two minutes after propofol administration were dose dependent for children 1-6 years of age, decreasing 5.3% and 8.1% for each 1 mg/kg of propofol, respectively. CONCLUSION: The amount of propofol needed to supplement sevoflurane in children 1-6 years of age can be expected to decrease after 4 minutes of sevoflurane.
Subject(s)
Deep Sedation/methods , Drug Dosage Calculations , Intubation, Intratracheal/methods , Methyl Ethers/administration & dosage , Propofol/administration & dosage , Age Factors , Anesthetics, Inhalation/administration & dosage , Anesthetics, Intravenous/administration & dosage , Blood Pressure/drug effects , Child , Child, Preschool , Female , Heart Rate/drug effects , Humans , Infant , Male , Pediatrics/methods , Sevoflurane , Time FactorsABSTRACT
Postoperative pain control in patients undergoing spine surgery remains a challenge for the anesthesiologist. In addition to incisional pain, these patients experience pain arising from deeper tissues such as bones, ligaments, muscles, intervertebral disks, facet joints, and damaged nerve roots. The pain from these structures may be more severe and can lead to neural sensitization and release of mediators both peripherally and centrally. The problem is compounded by the fact that many of these patients are either opioid dependent or opioid tolerant, making them less responsive to the most commonly used therapy for postoperative pain (opioid-based intermittent or patient-controlled analgesia). The purpose of this review was to compare all published treatment options available that go beyond intravenous opiates and attempt to find the best possible treatment modality.
