Wet forced-air warming blankets are ineffective at maintaining normothermia.

BACKGROUND: Forced-air warming systems have proven effective in preventing perioperative hypothermia. To date, reported adverse events relate primarily to overheating and thermal injuries. This study uses a simple model to show that forced-air warming blankets become ineffective if they get wet. METHODS: Temperature sensor probes were inserted into three 1-liter fluid bags. Group C bags served as the control. Groups D (dry) and W (wet) bags were placed on Bair Hugger(R) Model 555 (Arizant Healthcare, Inc., Eden Prairie, MN, USA) pediatric underbody blankets. The warming blanket for Group W bags was subsequently wet with irrigation fluid. Temperature was documented every 5 min. This model was repeated two times for a total of three cycles. Statistical analysis was performed using anova for repeated measures. RESULTS: Starting temperatures for each model were within a 0.3 degrees C range. Group C demonstrated a steady decline in temperature. Group D maintained and slightly increased in temperature during the observation period, while Group W exhibited a decrease in temperature at a rate similar to Group C. These results were significant at P < 0.005. CONCLUSIONS: A wet forced-air warming blanket is ineffective at maintaining normothermia. Once wet, the warming blanket resulted in cooling similar to the control group.

The effects of isoflurane and desflurane titrated to a bispectral index of 60 on the cortical somatosensory evoked potential during pediatric scoliosis surgery.

In this study, we compared the effect of isoflurane and desflurane on the posterior tibial somatosensory evoked potential recorded by scalp electrodes during correction of idiopathic scoliosis in pediatric patients. Depth of sedation was controlled by maintaining bispectral index (BIS) at 60 throughout the study. Comparison of patients breathing desflurane and isoflurane showed an evoked cortical amplitude (N37-P45) of 0.53 +/- 0.3 microV versus 1.3 +/- 0.8 microV (P = 0.014), respectively. In addition to this comparison, a crossover design was included whereby the desflurane or isoflurane received in the first part of the study was changed to the other anesthetic. Substituting one anesthetic for another confirmed our initial finding that the cortical evoked amplitude is greater with isoflurane than with desflurane. No differential effect was found between desflurane and isoflurane on the evoked subcortical (N31-P34) amplitude or the P37 latency.

Tracheal extubation of deeply anesthetized pediatric patients: a comparison of desflurane and sevoflurane.

UNLABELLED: In this study, we examined the emergence characteristics of children tracheally extubated while deeply anesthetized with desflurane (Group D) or sevoflurane (Group S). Forty-eight children were randomly assigned to one of the two groups. At the end of the operation, all subjects were tracheally extubated while breathing 1.5 times the minimal effective concentration of assigned inhaled anesthetic. Recovery characteristics and complications were noted. Group D patients had higher arousal scores on arrival to the postanesthesia care unit than Group S patients. Later arousal scores were not significantly different. No serious complications occurred in either group. Coughing episodes and the overall incidence of complications after extubation were more frequent in Group D. Readiness for discharge and actual time to discharge were not significantly different between groups. Emergence agitation was common in both groups (33% overall, 46% for Group D, and 21% for Group S). Narcotic administration in the postanesthesia care unit occurred more frequently in Group D (10 of 24 patients) versus Group S (3 of 24 patients). Premedication with oral midazolam resulted in significantly longer emergence times regardless of the potent inhaled anesthetic administered. IMPLICATIONS: Deep extubation of children can be performed safely with desflurane or sevoflurane. Airway problems occur more frequently with desflurane. Awakening occurs more quickly with desflurane. Midazolam premedication has a greater effect on emergence times than does the choice of inhaled anesthetic. Emergence agitation occurs frequently with either technique.