Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1993
Electroencephalographic burst suppression by propofol infusion in humans: hemodynamic consequences.
The hemodynamic effects of a propofol infusion adjusted to achieve and maintain a burst-suppression pattern [episodes of depressed background activity (electrical silence) more than 4 s alternating with a high-voltage slow activity], were studied in 10 patients without cardiorespiratory disease undergoing elective neurosurgical interventions. Propofol infusion was started after a bolus dose of 1 mg/kg at a rate of 20 mg.kg-1 x h-1, reduced after 30 min to 15 mg.kg-1 x h-1, and terminated after 60 min (1926 +/- 346 mg cumulative propofol dose, maximal serum concentration 9.2 +/- 2.9 micrograms/dL; mean +/- SD). Hemodynamic data and arterial blood samples were collected during a sedated, resting control period, and then every 15 min during drug infusion. ⋯ No adverse consequences were caused by the propofol or crystalloid infusion. The results demonstrate that doses of propofol sufficient to silence the electroencephalogram are associated with venodilating and myocardial depressant properties. However, propofol can be administered with minimal hemodynamic risk in healthy patients when cardiac filling pressures are maintained by intravenous fluid administration.
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Anesthesia and analgesia · Jul 1993
Laboratory evaluation of the Baxter Patient-Controlled Analgesia Infusor System: a disposable patient-controlled analgesia device.
The purpose of this study was to determine the accuracy of bolus-demand volumes obtained from the Baxter Patient-Controlled Analgesia Infusor System, a disposable patient-controlled analgesia device. An automated system was used to make demands in a pattern designed to simulate those made by a patient in the first 24 postoperative hours. Following this, a pattern of varying short interdemand intervals was used to evaluate performance of the device when demands were made near the nominal lockout interval of 6 min. ⋯ Evaluation near the nominal lockout interval revealed a departure of delivered volume from nominal (worst = 73.9% at an interdemand interval of 6 min). As the reservoir became exhausted, delivery increased to a maximum value, ranging from 118% to 137% of nominal, before falling to zero. In general, the devices performed consistently and the departures from nominal delivery were not considered to be of clinical significance.
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Anesthesia and analgesia · Jul 1993
Randomized Controlled Trial Comparative Study Clinical TrialForced-air warming maintains intraoperative normothermia better than circulating-water mattresses.
The hypothesis that forced-air warming preserves core temperature better than circulating-water mattresses was tested in: (a) 16 adults undergoing major maxillofacial surgery, including radical node resection and flap reconstruction; (b) 53 adults undergoing hip arthroplasty, having approximately 25% of their body surface area available for warming; (c) 20 infants undergoing minor maxillofacial surgery; and (d) 10 young children undergoing pelvic or femoral osteotomies. Patients having each type of surgery were randomly assigned to forced-air warming (approximately 40 degrees C) or conductive warming using a full-length circulating-water mattress at 40 degrees C. Forced-air warming was applied to the legs of the adults undergoing maxillofacial surgery and to one arm, the shoulders, and the neck in the adults undergoing hip arthroplasty; a U-shaped, tubular forced-air cover was positioned around the pediatric patients. ⋯ Furthermore, we needed to decrease the temperature of the warmer from high to medium (approximately 37 degrees C) in most patients assigned to forced-air warming to prevent hyperthermia. After 15 h of anesthesia, rectal temperatures in the adults undergoing maxillofacial surgery were 3.4 degrees C higher in the forced-air group (P < 0.01). After 4 h of anesthesia, esophageal temperatures had increased 0.8 +/- 0.5 degrees C in the patients warmed with forced-air and decreased 0.8 +/- 0.3 degrees C in those warmed by circulating-water mattresses (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Jul 1993
Comparative StudyManagement of intractable pain with percutaneous epidural spinal cord stimulation: differences in pain-relieving effects among diseases and sites of pain.
This study is a survey of the overall clinical results achieved with our pain treatment method, percutaneous epidural low-frequency (1.6-8.0 Hz) spinal cord stimulation. It examines the relationship between the effectiveness of epidural spinal cord stimulation (ESCS) and diseases or sites of pain. Continuous indwelling of the catheter electrodes in the posterior epidural space ranged from 3 to 67 days, and the duration of percutaneous ESCS varied from less than 1 wk to more than 1 yr. ⋯ Alleviation of pain by ESCS was lower when the verbal pain score was high. There were no major complications in percutaneous ESCS. Thus, we have demonstrated that pain-alleviating effects of ESCS varies significantly by disease and site of pain, and that this simple percutaneous method can be used for a relatively long period.
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Anesthesia and analgesia · Jul 1993
Psychosocial and pharmacologic predictors of satisfaction with intravenous patient-controlled analgesia.
Despite intravenous patient-controlled analgesia's (IV-PCA) increasing popularity, the psychological and pharmacological factors upon which patient satisfaction with IV-PCA are based are unknown. Sixty-eight women scheduled for abdominal hysterectomy completed a series of questionnaires measuring emotional distress, locus of control, perceived support, and optimism before their surgery. Postoperative ratings of pain intensity, emotional distress, anticipated recovery time, nightmares, and satisfaction with IV-PCA were taken 1 and 3 days after surgery. ⋯ Degree of dissatisfaction with IV-PCA was significantly correlated with pain intensity, nightmares, patient's perceptions of support, expectations of recovery, preoperative anxiety, and postoperative depression. Dose/demand ratio and hourly analgesic usage were significantly related to pre- and postoperative emotional distress factors. Perioperative management of anxiety, perceptions, and expectations may prove valuable in improving pain control and satisfaction with IV-PCA.