ABSTRACT
BACKGROUND: The extent to which insufflation of oxygen into the posterior pharynx during laryngoscopy prolongs adequate saturation in infants and small children remains unknown. Therefore, we compared oxygen saturation over time in preoxygenated small children with and without posterior pharynx oxygen insufflation. METHODS: After induction of anesthesia with sevoflurane and propofol, infants and small children were preoxygenated with 100% oxygen for 3 minutes. An AirTraq laryngoscope size 0 or 1 with an appropriately sized cuffed endotracheal tube positioned in the side channel was prepared. Oxygen tubing was connected to the endotracheal U-shaped tube. However, oxygen at a flow of 4 L/min was provided only to half of the randomly selected participating patients. The trachea was intubated, the tube cuff was inflated, and the laryngoscope was removed from the mouth. The oxygen tubing was disconnected from the endotracheal tube and left exposed to ambient air until oxygen saturation decreased to 95%. Thereafter, patients' lungs were manually ventilated with 100% oxygen until SpO2 returned to 100%. Subsequent anesthetic management was at the discretion of the attending anesthesiologist. RESULTS: Laryngoscopy took a median of 60 (Q1-Q3, 40-90) seconds. The mean time to 95% oxygen saturation was (mean ± SD) 166 ± 47 seconds in the oxygen insufflation group and 131 ± 39 seconds in small children without insufflation. Oxygen insufflation prolonged the mean time for saturation to decrease from 100% to 95% by an estimated 35 (95% confidence interval, 10-60) seconds, P = 0.01. CONCLUSIONS: Adding posterior pharyngeal oxygen insufflation to conventional preoxygenation prolonged the period of adequate oxygen saturation in infants and small children by an amount that is potentially clinically important.
Subject(s)
Insufflation/methods , Intubation, Intratracheal/methods , Laryngoscopy/methods , Oxygen/administration & dosage , Pharynx , Anesthesia, General/methods , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Methyl Ethers/administration & dosage , Pharynx/drug effects , Propofol/administration & dosage , SevofluraneABSTRACT
BACKGROUND: The intravenous anesthetic propofol is a gamma-aminobutyric acid A receptor agonist. Propofol promotes analgesia by depressing nociceptive transmission in peripheral neurons, antagonizing N-methyl-D-aspartate receptors, and activating gamma-aminobutyric acid A receptors in dorsal root ganglion receptor cells. Nevertheless, it remains unclear whether intraoperative propofol causes clinically meaningful postoperative analgesia. We therefore tested the hypothesis that patients anesthetized with sevoflurane require a greater quantity of postoperative opioids (from the end of surgery until the next postoperative morning) than those anesthetized with propofol. METHODS: With Institutional Review Board and EudraCT Number approval (2009-011038-82) and patients' informed consent, ninety patients scheduled for open vein stripping were randomized to either sevoflurane or propofol anesthesia at the Medical University of Vienna General Hospital and the Danube Hospital, the largest regional hospital in Vienna. Pain was treated with bolus piritramide and patient-controlled morphine hydrochloride. The primary outcome was total opioid use from the end of surgery until the first postoperative morning. For the initial four postoperative hours and on the first postoperative morning, a blinded investigator recorded pain scores on an 11-point Likert verbal response scale. RESULTS: The median [interquartile range] morphine sulfate equivalents were 9.8 [4-19] mg in the sevoflurane group and 10 [6-20] mg in the propofol group. Sevoflurane was not superior to propofol on postoperative opioid consumption, giving a ratio of means of 0.91 (95% interim-adjusted confidence interval [CI], 0.33 to 2.45; P = 0.74). Additionally, no difference in pain scores was found over time between the two groups, with a mean difference on an 11-point scale of 0.20 (95% interim-adjusted CI, -0.36 to 0.73; P = 0.31). CONCLUSION: Intraoperative sevoflurane did not reduce postoperative analgesia. This finding is consistent with the results in most previous reports. This trial was registered at ClinicalTrials.gov: NCT00712517.