Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1996
Comparative Study Clinical Trial Controlled Clinical TrialFetal heart rate changes after intrathecal sufentanil or epidural bupivacaine for labor analgesia: incidence and clinical significance.
The objective of this study was to compare the incidence of intrapartum fetal heart tracing (FHT) abnormalities and the obstetric outcome after intrathecal sufentanil (ITS) versus epidural bupivacaine (EB). During the period from April to September 1994, 129 patients who met inclusion criteria were prospectively identified during labor at a single university-affiliated hospital. Inclusion criteria included: singleton, gestational age > or = 36 wk, and cephalic presentation. ⋯ This increased risk was associated with an increase in cesarean section for nonreassuring FHT in both groups (ITS 14.3% [2/14] versus 0% [0/51], P = 0.04; EB 13.3% [2/15] versus 0% [0/49], P = 0.05). These results support the conclusion that the incidence of clinically significant FHT abnormalities and hypotension is equivalent in patients receiving ITS when compared to EB within the first hour of administration. During this period, patients should have continuous FHT monitoring since a new onset FHT abnormality unveils and alerts the physicians to a possible compromised fetal condition and a corresponding increased risk of cesarean section.
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Comparative Study Clinical TrialClonidine for major vascular surgery in hypertensive patients: a double-blind, controlled, randomized study.
The utility of clonidine for hypertensive patients presenting for major vascular procedures remains debatable. Twenty-one hypertensive patients presenting for aortic surgery were given clonidine (n = 11) or placebo (n = 10) in a double-blind, randomized manner. Clonidine was administered 6 micrograms/kg per os 120 min before induction of anesthesia and 3 micrograms/kg intravenously (i.v.) over 60 min from aortic declamping to skin closure. ⋯ Plasma concentrations of clonidine, alfentanil, and vasoactive hormones were measured. When the clonidine group was compared with the placebo group, (a) isoflurane, alfentanil, and midazolam requirements were reduced by 38%, 42%, and 41%, respectively (P = 0.04, 0.03, 0.0002, respectively); (b) supplemental circulatory and anesthetic adjustments were reduced by 51% (P = 0.0006); (c) interventions with vasopressors were not significantly increased (placebo: two; clonidine: five); (d) systolic and mean arterial pressures and heart rate were reduced; (e) increases in norepinephrine, epinephrine, and plasma renin activity were suppressed, whereas vasopressin surge was attenuated; and (f) chronotropic response to isoproterenol was unaffected. Clonidine was effective in reducing anesthetic requirements and in improving circulatory stability in hypertensive patients presenting for major vascular procedures.
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Comparative Study Clinical TrialClonidine increases the sweating threshold, but does not reduce the gain of sweating.
We tested the hypothesis that clonidine produces a dose-dependent increase in the sweating threshold but does not reduce the gain of sweating. Six healthy male volunteers were evaluated, each on three separate days in random order. In one, saline was administered; in another, a 2-micrograms/kg bolus of clonidine was followed by an infusion at 2 micrograms.kg-1.h-1, and on a third day, a 4-micrograms/kg bolus was followed by an infusion at 4 micrograms.kg-1.h-1. ⋯ These data suggest that the antishivering effect of clonidine results from central thermoregulatory inhibition rather than a specific peripheral action on thermogenic muscular activity. Unlike other sedatives and anesthetics, the concentration-dependence of clonidine demonstrates a ceiling beyond which the administration of an additional drug fails to enhance the effect, suggesting that the thermoregulatory effect of clonidine may be limited, even at high plasma concentrations. The gain of sweating was well preserved indicating that this response remains effective in the presence of sedatives and anesthetics.
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialAxillary brachial plexus anesthesia: electrical versus cold saline stimulation.
The aim of this study was to investigate which of two methods of nerve stimulation, cold saline-induced paresthesia or use of a nerve stimulator, was more effective in increasing the successful brachial plexus block rate by the axillary approach. Twenty patients were randomly assigned to Group A (saline below 11 degrees C), and 20 patients to Group B (nerve stimulator). All blocks were performed by the same anesthesiologist using 40 mL of 1.5% mepivacaine and 4 mL of 8.4% sodium bicarbonate. ⋯ A motor response was evoked by a nerve stimulator in 17 patients (85%). Two patients (10%) had a paresthesia in the hand without a motor response with the current at less than 1 mA. A successful block was achieved in 19 patients in each group.
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Anesthesia and analgesia · Oct 1996
Practice patterns of anesthesiologists regarding situations in obstetric anesthesia where clinical management is controversial.
A survey consisting of 47 questions, 40 regarding clinical practice and 7 regarding demographics, was mailed to 153 directors of obstetric anesthesia in academic practice and to 153 anesthesiologists in private practice. Questions relating to the following areas of practice were asked: 1) preoperative laboratory testing; 2) preeclampsia and possible coagulopathies; 3) epidural catheter placement in women with "spinal problems"; and 4) use of epidural opioids and intravenous supplementation. ⋯ These eight questions related to preoperative laboratory testing in the healthy parturient, preoperative laboratory testing in the preeclamptic patient, and the use of intravenous supplementation during a cesarean section with regional anesthesia. Although there were some differences in the responses between anesthesiologists in academic and private practice, overall the responses were similar.