Anesthesiology
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Multicenter Study
Frequency and Risk Factors for Difficult Intubation in Women Undergoing General Anesthesia for Cesarean Delivery: A Multicenter Retrospective Cohort Analysis.
Estimates for the incidence of difficult intubation in the obstetric population vary widely, although previous studies reporting rates of difficult intubation in obstetrics are older and limited by smaller samples. The goals of this study were to provide a contemporary estimate of the frequency of difficult and failed intubation in women undergoing general anesthesia for cesarean delivery and to elucidate risk factors for difficult intubation in women undergoing general anesthesia for cesarean delivery. ⋯ In this large, multicenter, contemporary study of more than 14,000 general anesthetics for cesarean delivery, an overall risk of difficult intubation of 1:49 and a risk of failed intubation of 1:808 were observed. Most risk factors for difficult intubation were nonobstetric in nature. These data demonstrate that difficult intubation in obstetrics remains an ongoing concern.
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Ketamine produces potent analgesia combined with psychedelic effects. It has been suggested that these two effects are associated and possibly that analgesia is generated by ketamine-induced dissociation. The authors performed a post hoc analysis of previously published data to quantify the pharmacodynamic properties of ketamine-induced antinociception and psychedelic symptoms. The hypothesis was that ketamine pharmacodynamics (i.e., concentration-effect relationship as well as effect onset and offset times) are not different for these two endpoints. ⋯ The authors conclude that their data support an association or connectivity between ketamine analgesia and dissociation. Given the intricacies of the study related to the pain model, measurement of dissociation, and complex modeling of the combination of ketamine and norketamine, it is the opinion of the authors that further studies are needed to detect functional connectivity between brain areas that produce the different ketamine effects.
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Effect of Nitrous Oxide and of Narcotic Premedication on the Alveolar Concentration Required for Anesthesia. By , Eger EI II. Anesthesiology 1964; 25:302-6. ⋯ A rare side effect of a volatile anesthetic is that in some patients, malignant hyperthermia may occur with or without succinylcholine use. This phenomenon was detected in a patient in whom halothane MAC was being measured. The availability of the Severinghaus blood gas device allowed for the first ever measurement of the metabolic and respiratory acidemia that accompanies malignant hyperthermia.
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Vigorous spontaneous effort can potentially worsen lung injury. This study hypothesized that the prone position would diminish a maldistribution of lung stress and inflation after diaphragmatic contraction and reduce spontaneous effort, resulting in less lung injury. ⋯ Prone position, independent of positive end-expiratory pressure levels, diminishes a maldistribution of lung stress and inflation imposed by spontaneous effort and mitigates spontaneous effort, resulting in less effort-dependent lung injury.