Articles: general-anesthesia.
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Anesthesia and analgesia · Sep 1990
Modulation of pain-related somatosensory evoked potentials by general anesthesia.
The aim of the present study was to assess if late somatosensory evoked cerebral potentials (SEPs) in response to painful electrical stimuli are a sensitive indicator for analgesic treatment during general anesthesia. For this purpose, a pain model developed for the quantification of drug-induced analgesia in awake volunteers was used in 10 patients scheduled for elective abdominal hysterectomy. Before induction of anesthesia, stimuli were adjusted to two and three times the pain threshold for each individual. ⋯ However, AEP components remained suppressed with increased auditory stimulus intensity. Addition of fentanyl (HF) suppressed SEP amplitudes and stimulus-induced hemodynamic responses. Our results suggest that late SEPs in response to painful stimuli change with different analgesic levels.
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It has been shown that a variable percentage of patients who receive a general anesthetic are significantly hypoxemic when they arrive at the recovery room. Pulse oximetry has proved to be a reliable method to determine arterial oxygen saturation when compared to arterial or mixed venous blood oxygen saturation measurements. The authors determined the incidence and severity of hypoxemia by pulse oximetry in 45 healthy adult patients, (non obese, non smokers) who underwent non thoracic surgery under general anesthesia. ⋯ The authors conclude that a significant number of healthy adult patients who are given a general anesthetic show severe hypoxemia when they arrive at the recovery room. The severe hypothermia found in these patients can aggravate the hypoxemia. They consider it is mandatory to control the temperature of and to administer oxygen in the recovery room to all patients who receive a general anesthetic.
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We have investigated the value of lower oesophageal contractility (LOC) in detecting awareness during anaesthesia in 20 human volunteer patients. LOC was measured either with subjects awake or after induction with propofol, during induction with propofol, and then as consciousness returned. Statistically significant changes were observed in the frequency of spontaneous contractions, peak and mean amplitude of spontaneous and provoked contractions, and the oesophageal contractility index as subjects lost consciousness and also as it was regained. The differences in LOC which occurred when subjects were conscious and unconscious support the view that LOC is related to the depth of anaesthesia, but its unreliability at the interface between consciousness and unconsciousness prevents selective detection of awareness, although the response in the presence of painful stimuli has not been tested.
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Ketamine was used as the sole anaesthetic during the induction-to-delivery interval in 20 full-term patients undergoing elective Caesarean section. The intravenous administration of ketamine 1.5 mg.kg-1 was followed by succinylcholine 1.5 mg.kg-1 and tracheal intubation. The mother's lungs were then ventilated using 100 per cent oxygen until the baby was delivered. ⋯ The isolated arm test was negative in all patients having an I-D interval less than 10 min, and was positive in three patients when the I-D interval exceeded ten minutes. The newborns of group A showed higher Apgar scores at one minute, as well as higher umbilical vein PO2 than was achieved in Group B. It was concluded that the technique used was not associated with maternal awareness or neonatal depression, provided that the I-D interval was less than 10 min and the U-D interval was less than 90 sec.
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J. Oral Maxillofac. Surg. · Aug 1990
Randomized Controlled Trial Comparative Study Clinical TrialPreanesthetic medication with rectal midazolam in children undergoing dental extractions.
Three different dosages (0.25, 0.35, and 0.45 mg/kg) of rectally administered midazolam were compared with each other and with placebo for preanesthetic medication in children undergoing dental extractions. Eighty patients between the ages of 2 and 10 years were randomly allocated into four groups in this double-blind study. ⋯ A high prevalence (23%) of disinhibition reactions was observed, particularly in the 0.45 mg/kg group. For this reason, 0.25 or 0.35 mg/kg appears to be the dose of choice when rectal midazolam is used for premedication in children.