Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2001
Clinical TrialA simple and inexpensive nasal cannula to prevent rebreathing for spontaneously breathing patients under surgical drapes.
A new nasal cannula that provides oxygenation and suctioning simultaneously prevents rebreathing during surgery in spontaneously breathing patients under surgical drapes. When air is not suctioned, inspired CO(2) levels increase significantly, whereas suctioning prevents this increase. Expiratory CO(2), respiratory rate, heart rate, and arterial blood pressure remain stable regardless of suctioning.
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Anesthesia and analgesia · Sep 2001
Randomized Controlled Trial Clinical TrialThe pressor response and airway effects of cricoid pressure during induction of general anesthesia.
Cricoid pressure (CP) has been used to protect the patient from regurgitation and gastric insufflation. Because the hemodynamic effects of CP have not been evaluated independently, we designed this prospective study. Eighty ASA I adult patients were prospectively included in the study. ⋯ Peak inspiratory pressure increased and tidal volume decreased significantly after the application of CP compared with the Control group and baseline values. Arterial blood pressure and heart rate increased significantly after the application of CP compared with the baseline values and with those of the Control group. The result of this study shows that CP can cause a relatively strong pressor response.
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Anesthesia and analgesia · Sep 2001
Randomized Controlled Trial Clinical TrialWhat constitutes an effective but safe initial dose of lidocaine to test a thoracic epidural catheter?
To investigate the effects of age and dose on the spread of thoracic epidural anesthesia, we placed thoracic epidural catheters in 50 surgical patients divided into groups by age (Group I [young], 18-51 yr; Group II [old], 56-80 yr) and randomly assigned patients to receive either 5 mL (A) or 9 mL (B) of 2% lidocaine (plain) injected via the epidural catheter. Hemodynamic variables were measured (heart rate, mean arterial blood pressure, noninvasive impedance cardiac index) at baseline and every 5 min for 30 min. Detectable blockade occurred within 8 min after injection of 3 + 2 mL or 3 + 6 mL in 48 of 50 patients. ⋯ Minor decreases in mean arterial blood pressure (8%-17%) and heart rate (4%-11%) were noted. Two patients in the Old 9 group required IV ephedrine or ephedrine/atropine to treat hypotension and bradycardia. We conclude that given the rapid onset (3-8 min), extensive spread (11-14 dermatomal segments), and consistent hemodynamic stability, thoracic epidural anesthesia should be initiated with lidocaine 100 mg (5 mL 2% lidocaine) to establish proper location of the catheter in the epidural space in both younger and older patients.
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Anesthesia and analgesia · Sep 2001
The injectable cyclooxygenase-2-specific inhibitor parecoxib sodium has analgesic efficacy when administered preoperatively.
Preoperative administration of analgesics may prevent or reduce hyperalgesia and inhibit inflammation and pain by reducing the synthesis of prostaglandins in response to surgical injury. We evaluated in this placebo-controlled study the analgesic efficacy and safety of single doses of parecoxib sodium (20, 40, and 80 mg IV) when administered before oral surgery. Efficacy assessments were recorded during the 24-h period after completion of surgery. ⋯ Forty-eight percent of the Parecoxib Sodium 40-mg group required rescue medication in the 24-h study period, compared with 93% of patients in the Placebo group. Overall, there were fewer adverse events in parecoxib sodium-treated patients compared with placebo. These findings suggest that preoperative administration of parecoxib sodium, the injectable prodrug of the cyclooxygenase-2 specific inhibitor valdecoxib, is effective, safe, and well tolerated for treating postoperative pain.
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Anesthesia and analgesia · Sep 2001
Comparative StudyThe in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria.
Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. ⋯ Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.