Anesthesia and analgesia
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Anesthesia and analgesia · May 1976
Analysis of tasks and human factors in anesthesia for coronary-artery bypass.
A comprehensive task analysis of the anesthetist's activities during coronary-artery bypass procedures was carried out using time-lapse cinematography. This film was analyzed frame by frame to detect types of activities and the proportion of time spent on each. Link analysis was used to reveal recurring sequences of activities. ⋯ Ten to 15% of the time is spent logging data on the anesthetic record. The challenge for the anesthetist is to optimize his performance, and those under his direction, in the face of the changing workload resulting from variations in patients' conditions. Use of an automated monitoring system that charts patient vital signs would allow the anesthetist to apportion this time among other tasks.
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Ketamine given IV in a dose of 2 mg/kg caused a significant reduction in Pao2 in 7 patients spontaneously breathing with an unassisted airway. Under the same conditions, in 7 patients, ketamine (2 mg/kg IV) preceded by diazepam (0.2 mg/kg IV) also caused a reduction in Pao2 not significantly different from that caused by ketamine. In some patients, alarmingly low levels of Pao2 ( less than or equal to 40 torr) were seen following ketamine administration. Based on these findings, the authors recommend that O2 and ventilatory assistance accompany ketamine given IV for anesthesia.
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Anesthesia and analgesia · Mar 1976
A comparative study of enflurane and halothane using systolic time intervals.
The effects of enflurane and halothane anesthesia on systolic time intervals were studied in 12 healthy patients. Cardiovascular measurements were made at equipotent levels of anesthesia: enflurane 1.23% end-tidal and halothane 0.65% end-tidal. ⋯ However, halothane caused significantly more myocardial depression than enflurane, as indicated by a larger preejection period (PEP) and preejection period/left ventricular ejection time (PEP/LVET) and a smaller 1/PEP2 and ejection fraction. When N2O was discontinued, both agents increased PEP and PEP/LVET and decreased 1/PEP2 and the ejection fraction.
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Anesthesia and analgesia · Mar 1976
Comparative StudyCardiovascular dynamics after large doses of fentanyl and fentanyl plus N2O in the dog.
The effects of large doses of fentanyl (0.05 to 2 mg/kg) and fentanyl plus N2O on cardiovascular dynamics were determined in 10 unpremedicated dogs breathing 100% O2. Using computer analysis of the central aortic pulsepressure curve, stroke volume (SV), cardiac output, heart rate (HR), peripheral vascular resistance (PVR), and systolic, diastolic, and mean arterial blood pressures (BP) were determined while fentanyl was being given at a rate of 0.3 to 0.44 mg/min. Fentanyl caused a dose-related decrease in HR, which was significant at 0.05 mg/kg. ⋯ Addition of N2O after fentanyl did not significantly change any parameter, although SV, cardiac output, and HR were usually increased and PVR decreased. These data demonstrate that, while large doses of fentanyl or fentanyl plus N2O do alter cardiovascular dynamics in dogs, the changes appear to be less profound than those produced by equianalgesic doses of morphine. Our findings suggest that large doses of fentanyl-O2 may be an attractive alternative to morphine-O2 anethesia in critically ill patients.
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Anesthesia and analgesia · Mar 1976
A technic of general anesthesia for blepharoplasty and rhytidectomy.
A series of 66 consecutive cases of blepharoplasty and rhytidectomy are reported, 60 of which were performed with a general anesthesia technic utilizing local anesthesia with epinephrine, in association with enflurane inhalation delivered via bilateral nasopharyngeal airways (BNPA). Six cases were not suitable candidates for the technic because of physical status or for anatomic reasons. The technic has teh advantage of providing airway control without tracheal intubation, light depth of anesthesia, compatibility with epinephrine, and highly acceptable limits of intraoperative bleeding and postoperative hematoma.