Articles: general-anesthesia.
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We have studied the effects of anaesthesia on atelectasis formation and gas exchange in 45 patients of both sexes, smokers and nonsmokers, aged 23-69 yr. None of the patients showed clinical signs of pulmonary disease, and preoperative spirometry was normal. In the awake patient, partial pressure of arterial oxygen (PaO2) decreased with increasing age (P less than 0.001) and the alveolar-arterial oxygen partial pressure difference (PAO2-PaO2) increased with age (P less than 0.001). ⋯ Atelectasis and shunt did not increase significantly with age, whereas log SD Q and perfusion of regions with low VA/Q ratios did (r = 0.55, P less than 0.001 and r = 0.35, P less than 0.05, respectively). Awake, the major determinant of PaO2 was perfusion of regions of low VA/Q ratios, which increased with age. During anaesthesia shunt influenced PaO2 most, low VA/Q being a secondary factor which, however, was increasingly important with increasing age, thus explaining the well-known age-dependent deterioration of arterial oxygenation during anaesthesia.
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Comparative Study Clinical Trial Controlled Clinical Trial
Spontaneous EMG activity for detection of arousal during general anaesthesia--comparison between recordings from frontal and neck musculature.
Monitoring of the spontaneous electromyographic activity of the frontal muscles (FEMG) is used for detection of impending arousal during general anaesthesia. Since the irritation caused by an endotracheal tube in situ might enhance the sensitivity of neck muscles in detecting arousal, EMG recordings from sternocleidomastoid muscles (NEMG) were compared to FEMG recordings under five different clinical conditions with 10 patients in each group. ⋯ The results thus support our initial hypothesis and favour the use of neck muscles for monitoring. This, however, does not allow simultaneous recording of EEG through the same electrodes.
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Propofol was used for the induction and maintenance of anesthesia in a patient undergoing a laparoscopic tubal ligation. This new anesthetic has not been associated with postoperative ventricular arrhythmias. This report demonstrates the occurrence of supraventricular tachycardia deteriorating to ventricular tachycardia in a patient who received propofol. Included is a discussion of the possible causes of this event.
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Comparative Study Clinical Trial Controlled Clinical Trial
Neuromuscular effects of pipecuronium bromide.
The neuromuscular effects of pipecuronium bromide have been evaluated in 90 adult patients anaesthetized with thiopentone, nitrous oxide in oxygen and intravenous fentanyl with or without halothane. Eighty patients received pipecuronium 45 micrograms kg-1 and the remaining ten 70 micrograms kg-1. A separate group of 10 patients received pancuronium in a dose of 60 micrograms kg-1 (equipotent to pipecuronium 45 micrograms kg-1). ⋯ The time to onset of complete block with 70 micrograms kg-1 of pipecuronium averaged 2.5 min and the duration to 25% recovery 95 min. There were no significant changes in heart rate and arterial pressure with the use of pipecuronium. The results show pipecuronium to be a drug resembling pancuronium in its neuromuscular effects when used in equipotent doses.