Journal of anesthesia
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Journal of anesthesia · Mar 1995
RETRACTED ARTICLE: Effects of nicardipine on diaphragmatic fatigue in the dog: The relationship between dosage and fatigability.
We examined the dose-related effects of nicardipine on the diaphragmatic fatigability in 24 anesthetized, mechanically ventilated dogs. Animals were divided into three groups of eight each: the control group (group C), the nicardipine 3 μg·kg(-1) I. V. group (group N1) and the nicardipine 5 μg·kg(-1)·min(-1) I. ⋯ The speed of recovery of Pdi at 20 Hz stimulation was dose dependent. The integrated diaphragmatic electric activity (Edi) in each group did not change at any frequency of stimulation throughout the study. Our results demonstrate that nicardipine causes a dose-dependent reduction of the contractility of the fatigued diaphragm.
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Journal of anesthesia · Mar 1995
Spinal function monitoring by evoked spinal cord potentials in aortic aneurysm surgery.
Evoked spinal cord potentials (ESCPs) were monitored in 12 patients who underwent repair of thoracoabdominal aortic aneurysm with a high risk of spinal ischemia. A pair of bipolar catheter electrodes were introduced into the epidural space, one at the level of the C5-T2 vertebrae and the other at the level of T11-L2. Conductive mixed ESCP in seven patients, conductive sensory ESCP in one patient, and segmental descending ESCP in three patients were observed by applying a rectangular electric current to one of each pair of epidural electrodes and recording through the other. ⋯ The N wave of segmental descending ESCP subsequently flattened in two of the three patients and the N1 wave of segmental ESCP in the one patient. Three of the four patients in whom the ESCPs disappeared during aorta clamping recovered the ESCPs after declamping and showed no neurological disorders postoperatively. Intraoperative ESCP monitoring appears to be useful to detect spinal cord ischemia in the early stage and to alert surgeons and anesthesiologists so that timely resuscitative steps can be taken.
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Journal of anesthesia · Mar 1995
Ischemia may be less detrimental than anemia for O2 transport because of CO 2 transport: A model analysis.
We analyzed the relationship between oxygen delivery (Do2) and Pto2 (tissue Po2). We found an important factor which has not been specified before. In the previous O2 transport model, Do2 was a dependent variable, calculated from hemoglobin, blood flow, Pao2, and the oxygen dissociation curve (ODC). ⋯ In ischemia the CO2 transport is disturbed, leading a higher draining venous Pco2, which in turn maintains a higher Po2 the capillary, resulting in a higher gradient for Po2 between capillary and the tissue. Between ischemia and anemia, ischemia is less detrimental than anemia. In ischemia, the CO2 transport is disturbed, which in turn maintains a higher Po2 at the capillary.
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Journal of anesthesia · Mar 1995
The patency of the airway via each upper airway orifice during general anesthesia.
The patency of the airway via each orifice was examined during general anesthesia in 112 patients by occluding other orifices in order to develop a method in which fiberoptic endotracheal intubation (FEI) and ventilation could be performed via different orifices. Ventilation was well maintained via the mouth in 61 (54.5%), via bilateral nostrils in 87 (77.7%), and via the unilateral right and left nostril in 67 (59.8%) and 73 (65.2%) patients, respectively. With the aid of an artificial airway, ventilation was well maintained via the mouth in 112 (100.0%), via bilateral nostrils in 111 (99.1%), and via the unilateral right and left nostril in 106 (94.6%) and 105 (93.8%) patients, respectively. Based on these findings, we developed a method in which FEI is performed via the nostril, while ventilation is performed with a mask applied over only the mouth.
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Journal of anesthesia · Mar 1995
Optimal administration time of intramuscular midazolam premedication.
The optimal administration time for intramuscular injection of midazolam as premedication was studied. Sixty patients ranging in age from 40 to 65 were included. A combination of atropine 0.3-0.5 mg and midazolam 0.08 mg·kg(-1) was given to four groups of 15 subjects each in intramuscular injections 45, 30, 15 min, and immediately before entering the operating room. ⋯ The depression of the root of the tongue, disappearance of verbal response, and eyelash reflex were found in the 30- and 45-min groups. The degree of sedation and amnestic effect were good except for the group who received midazolam immediately before entering the operating room. From the above results, intramuscular injection of midazolam 0.08 mg·kg(-1) with atropine 0.3-0.5 mg is considered best when administered 15 min before entering the operating room.