Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1997
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of epidural fentanyl on hemodynamic responses during emergence from isoflurane anesthesia and tracheal extubation: a comparison with intravenous fentanyl.
To investigate the effects of epidural fentanyl infusion on hemodynamic responses to recovery of consciousness and tracheal extubation, we studied 50 unpremedicated patients scheduled for abdominal hysterectomy. All patients underwent epidural catheterization and blind infusion of placebo and study drug. Patients were assigned randomly to three groups: Group I received epidural and intravenous (i.v.) bolus injections and infusion of saline at the rate of 0.2 mL x kg(-1) x h(-1); Group II received an i.v. injection of fentanyl 2 microg/kg for 30 s followed by 25 ng x kg(-1) x min(-1), and Group III received epidural injection and infusion using the same administration regimen as Group II. ⋯ The incidence of coughing during and after extubation was also lower with Group III. Suppression of respiratory rate prior to tracheal extubation was similar in the two groups receiving fentanyl. These findings suggest that the significant reduction in arterial pressures responses to tracheal extubation due to epidural fentanyl infusion may arise from more suppression of cough reflex than i.v. fentanyl infusion, which could be provided by the spinal action of epidural fentanyl as well as the supraspinal action.
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Anesthesia and analgesia · Aug 1997
Randomized Controlled Trial Comparative Study Clinical TrialEffect of the intensity of transcutaneous acupoint electrical stimulation on the postoperative analgesic requirement.
Given the inherent side effects associated with both opioid and nonopioid analgesic drugs, a nonpharmacologic therapy that could decrease the need for analgesic medication would be valuable. We designed a sham-controlled study to assess the effect of the intensity of transcutaneous acupoint electrical stimulation (TAES) on postoperative patient-controlled analgesia (PCA) requirement for hydromorphone (HM), the incidence of opioid-related side effects, and the recovery profile after lower abdominal surgery. One hundred one healthy consenting women undergoing lower abdominal procedures with a standardized general anesthetic technique were randomly assigned to one of four postoperative analgesic treatment regimens: Group I (n = 26) PCA only; Group II (n = 25), PCA + sham-TAES (no electrical stimulation); Group III (n = 25), PCA + low-TAES (4-5 mA of electrical stimulation); Group IV (n = 25), PCA + high-TAES (9-12 mA of electrical stimulation). ⋯ High-TAES decreased the HM requirement by 65% and reduced the duration of PCA therapy, as well as the incidence of nausea, dizziness, and pruritus. Low-TAES produced a 34% decrease in the HM requirement compared with only 23% in the "sham" TAES group. We conclude that high-TAES produced a significant decrease in the PCA opioid requirement and opioid-related side effects after low intraabdominal surgery.
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Anesthesia and analgesia · Aug 1997
Randomized Controlled Trial Clinical TrialThe effect of ephedrine on the onset time of rocuronium.
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Anesthesia and analgesia · Aug 1997
Comparative StudyLaser Doppler skin blood flow and sympathetic nervous responses to surgical incision during halothane and isoflurane anesthesia.
The aim of the present study was to evaluate whether a sudden decrease in skin blood flow measured using a laser Doppler velocimeter reflects sympathetic nervous response to surgical skin incision during halothane (n = 17) and isoflurane (n = 16) anesthesia in 33 ASA physical status I or II patients scheduled for laparotomy. Plasma norepinephrine concentrations in the responding patients who showed a sudden decrease in the skin blood flow after surgical incision increased significantly and continued to increase 1-10 min after skin incision under halothane and isoflurane anesthesia. Although plasma norepinephrine concentrations in the nonresponders did not increase after surgical incision with halothane, the concentrations increased significantly at 1 min, but not at 3 and 10 min, after skin incision with isoflurane. ⋯ Plasma epinephrine concentration increased during skin incision, but the concentrations did not differ between the patients with and without a sudden decrease in skin blood flow. Increases in systolic blood pressure and rate-pressure product on skin incision were also significantly more in patients with skin blood flow response compared with those without the response. The magnitude of changes in plasma norepinephrine concentration and hemodynamic variables with skin incision was greater with isoflurane than with halothane at the same minimum alveolar anesthetic concentration level.
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Anesthesia and analgesia · Aug 1997
Comparative StudyRadial artery diameter decreases with increased femoral to radial arterial pressure gradient during cardiopulmonary bypass.
A clinically significant femoral to radial artery pressure gradient sometimes develops during cardiopulmonary bypass (CPB), but the mechanism responsible is not clear. We investigated when the pressure gradient developed and what mechanism could be responsible by comparing mean femoral to mean radial artery pressure and radial artery diameter in 75 male patients undergoing coronary artery bypass grafting. A pressure gradient > or =5 mm Hg (High-P) occurred in 38 patients, and the remaining 37 patients had pressure gradients <5 mm Hg (Low-P) at sternal closure. In High-P group, the pressure gradient was significantly greater (4.8 +/- 3.1 vs 1.0 +/- 3.1 mm Hg; P < 0.001) than in Low-P group, and the ratio of radial artery diameter to the diameter after induction of anesthesia was significantly decreased (0.79 +/- 0.12 vs 0.87 +/- 0.14; P = 0.006) at 5 min after aortic clamping. The pressure gradient and the arterial diameter changes persisted until sternal closure. There was a negative linear correlation between the pressure gradient (deltaP) and the radial artery diameter ratio (D) at sternal closure (D = -15.0deltaP + 16.6, r = 0.39, P < 0.001). In a subgroup of 11 High-P patients, palm temperature was significantly lower (P < 0.05) than that of 11 Low-P patients during and after CPB. We conclude that the femoral to radial artery pressure gradient develops by 5 min after aortic clamping during CPB and persists until sternal closure, and that radial artery constriction could be responsible for the pressure gradient. ⋯ A femoral to radial pressure gradient has been observed after cardiopulmonary bypass. Arterial vasodilation and vasoconstriction have been considered as causes for this gradient. We measured radial artery diameter using pulsed Doppler ultrasound and examined radial artery vasodilation versus vasoconstriction as possible mechanisms for the pressure gradient.