Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2004
Clinical TrialAuscultation of bilateral breath sounds does not rule out endobronchial intubation in children.
We performed orotracheal intubation in 153 consecutive pediatric patients undergoing cardiac catheterization. Auscultation of bilateral breath sounds was confirmed. By fluoroscopy, the tip of the endotracheal tube (ETT) was seen in the right mainstem bronchus in 18 patients (11.8%) and in a low position, defined as within 1 cm above the carina, in 29 patients (19.0%). ⋯ Suggested measures for preventing endobronchial intubation include maintaining increased awareness of the imperfection or lack of accuracy of the auscultatory method, assessing insertion depth by checking the length scale on the tube, and minimizing the patient's head and neck movement after intubation. When extreme flexion or extension of the neck is expected after ETT insertion, the resultant change in ETT final position must be anticipated and taken into consideration when deciding on the depth of ETT insertion. This approach resulted in a decrease in improper tube positioning from 20% when the study was initiated to 7.1% in the last 98 patients.
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Anesthesia and analgesia · Jul 2004
Case ReportsRecombinant factor VIIa for life-threatening bleeding in high-risk cardiac surgery despite full-dose aprotinin.
We report the case of an orthotopic heart transplant in a patient with multiple previous cardiac surgeries. The case was prolonged and complicated by severe coagulopathy and bleeding despite the use of full-dose aprotinin throughout. ⋯ There was no evidence of unwanted clot formation within the newly transplanted heart or around the intraaortic balloon pump that remained in situ for 72 h postoperatively. With the combined risks of coagulopathy and bleeding as well as acute right ventricular failure with increases in pulmonary vascular resistance, the re-do sternotomy for heart transplant seems to be an ideal situation in which to consider the use of recombinant factor VIIa.
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Anesthesia and analgesia · Jul 2004
Inhibition of spinal protein kinase C-epsilon or -gamma isozymes does not affect halothane minimum alveolar anesthetic concentration in rats.
Anesthetic effects on receptor or ion channel phosphorylation by enzymes such as protein kinase C (PKC) have been postulated to underlie some aspects of anesthesia. In vitro studies show that anesthetic effects on several receptors are mediated by PKC. To test the importance of PKC for the immobility produced by inhaled anesthetics, we measured the effect of intrathecal injections of PKC-epsilon and -gamma inhibitors on halothane minimum alveolar anesthetic concentration (MAC) in 7-day-old and 21-day-old Sprague-Dawley rats. ⋯ In P21 animals, the values were 1.20 +/- 0.0490, 1.31 +/- 0.0124, 1.27 +/- 0.0367, and 1.15 +/- 0.0483, respectively. Injection of the inhibitors did not change MAC in either age group. These results do not support an anesthetic effect on phosphorylation as a mechanism underlying the capacity of inhaled anesthetics to prevent movement in response to noxious stimulation, and they indirectly support a direct action on receptors or ion channels.
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Anesthesia and analgesia · Jul 2004
A neuronal mechanism of propofol-induced central respiratory depression in newborn rats.
The neural mechanisms of propofol-induced central respiratory depression remain poorly understood. In the present study, we studied these mechanisms and the involvement of gamma-aminobutyric acid (GABA)A receptors in propofol-induced central respiratory depression. The brainstem and the cervical spinal cord of 1- to 4-day-old rats were isolated, and preparations were maintained in vitro with oxygenated artificial cerebrospinal fluid. ⋯ In contrast, propofol had little effect on resting membrane potentials and action potential firing in inspiratory neurons. Our findings suggest that the depressive effects of propofol are, at least in part, mediated by the agonistic action of propofol on GABAA receptors. It is likely that the GABAA receptor-mediated hyperpolarization of preinspiratory neurons serves as the neuronal basis of propofol-induced respiratory depression in the newborn rat.