Anesthesia and analgesia
-
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.
-
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.
-
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.
-
Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialPropofol and alfentanil prevent the increase in intraocular pressure caused by succinylcholine and endotracheal intubation during a rapid sequence induction of anesthesia.
The increase in intraocular pressure (IOP) associated with succinylcholine (Sch) has made its use in patients with open globe injuries controversial. Studies that have examined techniques to prevent the increase in IOP due to Sch have shown a larger increase in IOP from the stimulus of laryngoscopy and endotracheal intubation. The purpose of our study was to examine whether the combination of propofol and alfentanil would prevent the increase in IOP due to Sch as well as endotracheal intubation during a rapid sequence induction of anesthesia. ⋯ During the entire study period, the IOP in Group III never increased above baseline. The IOP in Groups I and II had already begun to decline by 15 s postintubation, suggesting that laryngoscopy and intubation have the greatest effect on increasing IOP. We conclude that the combination of propofol and alfentanil prevents the increase in IOP from Sch as well as the increase associated with endotracheal intubation during a rapid sequence induction of anesthesia.
-
Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialThe effects of desmopressin and 6% hydroxyethyl starch on factor VIII:C.
In moderate doses of 20 mL/kg (1.2 g/kg), hydroxyethyl starch (HES) 6% decreases factor VIII:C activity. Desmopressin (DDAVP) increases circulating levels of factor VIII:C by stimulating the release of factor VIII:C from peripheral storage sites. The objective of this study was to monitor the changes in factor VIII:C associated with sequential HES and DDAVP administration. ⋯ After HES administration, factor VIII:C levels decreased significantly, to 69% of baseline, in both groups. After study drug administration, factor VIII:C in Group 1 increased significantly to 135% of baseline at 30 min and 115% of baseline at 60 min while in Group 2 average factor VIII:C levels remained below baseline at 30 and 60 min. DDAVP produced an increase in factor VIII:C activity despite HES administration and should be considered a treatment option for the mild coagulopathy infrequently associated with HES administration.