ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Postoperative adrenocortical function was compared in 23 outpatients receiving either thiopental, 4 mg/kg, for induction and a thiopental infusion, 0.26 mg·kg−1min−1in combination with nitrous oxide 70% for maintenance of anesthesia (control); etomidate, 0.4 mg/kg, for induction followed by an etomidate infusion, 0.02 mg·kg−1·min−1, and nitrous oxide 70% for maintenance (etomidate 1); or etomidate, 0.4 mg/kg, for induction and a thiopental infusion, 0.22 mg·kg−1·min−1, in combination with nitrous oxide 70% for maintenance (etomidate II). The norepinephrine response to anesthesia and surgery did not differ significantly between the three groups. The postoperative cortisol response to ACTH stimulation was normal in the control group (maximum rise in plasma cortisol was 20.1 ± 2.9 μg/dl [mean ± SEM]), however, it was decreased in all patients receiving etomidate, whether by a short infusion (mean change in plasma cortisol was −3.8 ± 1.9 μg/dl) or as a single induction dose (mean change in plasma cortisol was −4.0 ± 2.0 μg/dl). Similarly, the postoperative aldosterone levels in the control group increased normally in response to ACTH (+10.2 ± 3.0 ng/dl) but decreased in both the etomidate I and etomidate II groups (−3.0 ± 0.7 ng/dl and −3.3 ± 1.0 ng/dl, respectively). Because ACTH was administered exogenously, etomidate-induced suppression of adrenocortical response appeared to be a direct effect on the adrenal gland, which was present at a time when the serum etomidate levels were in the subhypnotic range. Anesthetists using etomidate should be aware that biochemical adrenocortical suppression may follow even a single induction dose of this drug. Furthermore, adrenal steroid supplementation may be required if patients receiving etomidate develop an unexpected stress during the early postoperative period.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The hormonal responses to surgical stress were examined in 10 patients scheduled for elective gynecologic laparotomy. Anesthesia was induced with either thiopental, 4 mg/kg, or etomidate, 0.35 mg/kg, and maintained with nitrous oxide and enflurane. Plasma cortisol, aldosterone, ACTH, and catecholamines were measured during the 24 h after the induction of anesthesia. The catecholamine responses of the patients whose anesthesia was induced with either drug were similar. The plasma ACTH concentrations for the etomidate group were greater than baseline values and the concentrations in the thiopental group (P< 0.05) in the fourth and fifth hours. In the patients receiving thiopental, both cortisol and aldosterone concentrations were greater than the baseline value (P< 0.05) in the second to fourth hours after induction. In the etomidate group, the plasma concentrations of cortisol were less than baseline values (P< 0.05) in the first and second hours after induction of anesthesia and both cortisol and aldosterone were lower than those in the thiopental group (P< 0.05) in the half to fourth hours after induction. These results confirm an earlier report of the suppression of cortisol after etomidate administration and, because aldosterone also was suppressed, suggests that etomidate exerts its effect by inhibiting early stages of steroidogenesis in the adrenal cortex.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Halothane, enflurane, and isoflurane were evaluated for antifibrillatory efficacy and compared with lidocaine, propranolol, procainamide, and verapamil in a canine acute left anterior descending (LAD) coronary artery occlusion/reperfusion model with basal pentobarbital anesthesia. Of the antiarrhythmic drugs, only verapamil prevented ventricular fibrillation during occlusion and reperfusion. Halothane 1% inspired after 15 min showed similar protection. Enflurane 2.5% inspired after 15 min resulted in significant protection but caused hypotension after occlusion in 4 of 17 dogs. Isoflurane 1.7% inspired after 15 min showed intermediate results. At inspired concentrations of 0.5% and 1.25%, respectively, halothane and enflurane protected against ventricular fibrillation without hypotension. It is concluded that the volatile anesthetics have antifibrillatory effects in this canine model but differ in their ability to cause hypotension in the presence of proximal LAD coronary artery occlusion.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The authors studied the effect of lidocaine infusion on the ventilatory response to isocapnic hypoxia in nine healthy male subjects. Lidocaine infusion (serum concentration 3.6 ± 0.1 μg/ml) was associated with a decrease in the shape factor, “A,” of the hypoxic ventilatory response in eight of our nine subjects (P< 0.02). Overall, “A” decreased from 419 ± 102 1·min−1·mmHg before lidocaine to 335 ± 77 1·min−1·mmHg during lidocaine infusion (&OV0335; ± SEM, N = 9). The authors conclude that despite significant intersubject variability, clinically useful serum lidocaine concentrations depress hypoxic ventilatory drive. Patients with carbon dioxide retention, whose resting ventilation depends on hypoxic drive, may be at risk of ventilatory failure when lidocaine is administered for arrhythmia control or regional anesthesia.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Thiopental pharmacokinetics and protein binding were determined in 24 pediatric surgical patients with normal hepatic and renal function, ranging in age from 5 months to 13 yr. These pharmacokinetic data were compared with those from 11 adult patients previously studied at our institution. All pediatric patients received a single intravenous bolus of thiopental, 4.0 ± 0.08 mg·kg−1(mean ± SD), while the adult patients received 6.0 ± 0.74 mg·kg−1. Distribution phase kinetics and volume of distribution at steady state (Vd,,) did not differ statistically between the two groups. The degree of serum protein binding of thiopental also was similar in pediatric and adult patients with free fractions of 13.2% ± 1.5% and 13.6% ± 1.3%, respectively. The two patient groups showed a marked difference in elimination half-time and clearance of thiopental. Total drug clearance was 6.6 ± 2.2 ml·kg−1·min−1for pediatric patients and 3.1 ± 0.5 ml·kg−1·min−1for adults (P< 0.001). The elimination half-time of 6.1 ± 3.3 hours found in pediatric patients was significantly shorter (P< 0.005) than that for adults, 12 ± 6 hours. Linear regression of the pediatric data failed to achieve significance (P= 0.06) for elimination half-time to increase with age, while clearance decreased (P< 0.001) with increasing age. The shorter elimination half-time seen in infants and children was due solely to greater hepatic clearance. Thus, recovery time after large or repeated doses may be more rapid for infants and children than for adults because of the higher clearance.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The ability of halothane (used in “sub-MAC” concentrations) to modify the effect of morphine on motor response threshold to pressure was studied and compared with pentobarbital in 241 rat experiments. It was found that halothane (0.5–0.7%, insp.) decreased the reaction threshold to pressure, as did pentobarbital. Halothane (0.5%) increased morphine ED50for the reaction threshold to pressure from 0.21 mg·kg−1(95% fiducial limits: 0.13–0.29 mg·kg−1) to 0.52 mg·kg−1(0.28–0.73 mg·kg−1,P< 0.0001). Pentobarbital in a dose of 3 mg·kg−1demonstrated a similar antanalgesic effect. Neither halothane nor pentobarbital antagonized the effect of morphine with motor response to the tail clamp. On the contrary, both agents strengthened this effect. It has been suggested that the effect of morphine on the motor response threshold to pressure results primarily from activation of inhibitory control mechanisms concerned with this response; halothane in a subanesthetic concentration depresses the inhibitory control mechanisms and, therefore, weakens the effect of morphine.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The effects of intrathecal (IT) administration of two doses of morphine (Group 1: 2 mg, n = 9; Group 2: 5 mg, n = 10) were studied in 19 patients after upper abdominal surgery. The ventilatory variables and occlusion pressure (P0.1) were recorded during room air breathing and during CO2rebreathing tests prior to surgery, 24 h after surgery before IT morphine (n = 12), and 3, 5, 7, 11, and 24 h after injection. During room air breathing, minute ventilation (VE) did not change significantly in Group 1 and decreased significantly 3, 5, 7, and 11 h after injection in Group 2. During the rebreathing tests, there was a significant shift to the right of the ventilatory response to CO2in both groups. The peak of the ventilatory depression was delayed, occurring 7 h and 11 h postinjection in Groups 1 and 2, respectively. Two patients in Group 2 developed clinically significant ventilatory depression. The shallow breathing observed after surgery was not changed after analgesia. In group 2, 5, mg IT morphine was responsible for a significant decrease in f60(respiratory frequency for a PETCO2of 60 mmHg). P0.1increased markedly after surgery during both room air breathing and the rebreathing tests. After IT morphine, compared with the postoperative preanalgesic values, P0.160(P0.1at a PetCO2of 60 mmHg) did not change in Group 1 and decreased significantly in Group 2. It is concluded that IT morphine is responsible for a ventilatory depression that is delayed and seems to be dose related and that analgesia does not abolish the shallow breathing observed after upper abdominal surgery.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Forty-six male Sprague-Dawley rats were divided in five groups: awake animals and those receiving ketamine, halothane, enflurane, or isoflurane anesthesia. Cannulae were inserted into the left femoral artery and vein and the left ventricle. Inspired concentrations of the volatile anesthetics were adjusted to achieve the minimal alveolar concentration (MAC) of each drug. Ketamine, 125 mg·kg−1, was injected intraperitoneally and then infused at a rate of 1 mg·kg−1·min−1. All animals breathed spontaneously throughout the experiment (Flo2= 0.3). Following a 2-h stabilization period, 30% of estimated blood volume was withdrawn gradually over 10 min. Immediately before and 20 min after hemorrhage, cardiac output and regional blood flows were measured by the microsphere method (85Sr,141Ce-labeled 15-μm microspheres, respectively). Arterial blood samples were analyzed for Po2, Pco2,pH, lactate, and pyruvate at these times also. Prior to hemorrhage, cardiac output (CO) values were similar in awake rats and those receiving ketamine or isoflurane, but CO was reduced moderately by enflurane and to a greater extent by halothane. After hemorrhage, CO was greatest in awake animals and those receiving isoflurane, and awake rats tended to have the greatest organ blood flows. Values of lactate/pyruvate and excess lactate were least in awake animals. Overall results suggested that, in terms of cardiac output and regional blood flows, ketamine approximates the awake state most closely in normovolemic animals, whereas isoflurane anesthesia is most like the awake condition after hemorrhage.

ISSN:0003-3022    

出版商:OVID    

年代:1984

数据来源: OVID