Anesthesiology
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An animal model was developed to evaluate the accuracy of pulse oximetry over a wide range of oxyhemoglobin desaturation. The fractional inspired oxygen concentration was varied from 0.03-1.0 in five anesthetized dogs. One hundred and twelve simultaneous pulse oximeter oxygen saturation measurements (SpO2) and IL 282 CO-Oximeter arterial oxygen saturation (SaO2) measurements were made. ⋯ Spectral analyses of oxygenated (O2Hb) and reduced (RHb) canine and human hemoglobins were performed. The absorption spectra of canine O2Hb and RHb were nearly identical to those of human O2Hb and RHb. Therefore, 1) SpO2 measurements in dogs at SaO2 greater than 22% are relatively accurate, and 2) hemoglobin absorption characteristics support the contention that such canine pulse oximeter studies can be extrapolated to humans.
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The treatment of venous air embolism by aspiration from central venous catheters is well established. However, some anesthesiologists prefer to use a pulmonary artery catheter to monitor patients undergoing a neurosurgical procedure in the sitting position. While offering certain advantages, pulmonary artery catheters may be of limited use in the treatment of venous air embolism because the small diameter of the proximal port is poorly suited for efficient air aspiration. ⋯ The rank order of flow rate was: Bunegin-Albin CVP greater than introducer sheath without side holes = introducer sheath with side holes greater than Sorenson CVP greater than pulmonary artery catheter (P = 0.0001). The introducer sheath was then compared to a pulmonary artery catheter for the treatment of a 4 ml/kg venous air embolism in sitting, anesthetized dogs. The mean proportion of air retrieved by the sheath with or without side holes, 57% and 80%, respectively, was significantly greater than that retrieved by simultaneous aspiration of atrial and distal ports of the pulmonary artery catheter, 16% (P = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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A prospective cohort study of 489 pediatric patients was performed to investigate the prevalence of perioperative respiratory complications and symptomatology in children presenting for myringotomy with upper respiratory tract infections (URIs). All children undergoing myringotomy received halothane N2O/O2 anesthesia administered via face mask. Information on complications and respiratory symptoms was obtained from the anesthesia and recovery room records, and by standardized questionnaire. ⋯ In addition, the prevalence and duration of respiratory symptoms was significantly less in children having received anesthesia and surgery than in a matched group of non-anesthetized controls who did not have surgery. Results from this study suggest that there is no increased morbidity for children presenting at minor surgery with acute uncomplicated URIs and who did not require tracheal intubation. In addition, the administration of general anesthesia and surgery to this group of patients was followed by a decrease in both the appearance and duration of a number of respiratory symptoms.