Anesthesia and analgesia
-
Anesthesia and analgesia · Aug 1999
Randomized Controlled Trial Clinical TrialJugular bulb oxygen saturation during propofol and isoflurane/nitrous oxide anesthesia in patients undergoing brain tumor surgery.
We investigated, in brain tumor patients, the jugular bulb venous oxygen partial pressure (PjO2) and hemoglobin saturation (SjO2), the arterial to jugular bulb venous oxygen content difference (AJDO2), and middle cerebral artery blood flow velocity (Vmca) during anesthesia, and the effect of hyperventilation on these variables. Twenty patients were randomized to receive either isoflurane/ nitrous oxide/fentanyl (Group 1) or propofol/fentanyl (Group 2). At normoventilation (PacO2 35 +/- 2 mm Hg in Group 1 and 33 +/- 3 mm Hg in Group 2), SjO2 and PjO2 were significantly higher in Group 1 than in Group 2 (SjO2 60% +/- 6% and 49% +/- 13%, respectively; P = 0.019) (PjO2 32 +/- 3 and 27 +/- 5 mm Hg, respectively; P = 0.027). In Group 2, 5 of 10 patients had SjO2 < 50%, and 3 of these patients had SjO2 < 40% and AJDO2 > 9 mL/dL. All patients in Group 1 had SjO2 > 50%. During hyperventilation, there were no differences in SjO2, PjO2, or AJDO2 between the two groups. On hyperventilation, there was no correlation between the relative decreases of Vmca and 1/AJDO2 (r = 0.21, P = 0.41). The results indicate during propofol anesthesia, half of the brain tumor patients showed signs of cerebral hypoperfusion, but not during isoflurane/nitrous oxide anesthesia. Furthermore, during PacO2 manipulations, shifts in Vmca are inadequate to evaluate brian oxygen delivery in these patients. ⋯ During propofol anesthesia at normoventilation, 50% of brain tumor patients showed signs suggesting cerebral hypoperfusion, but this could not be demonstrated during isoflurane/nitrous oxide anesthesia. During PacO2 manipulations, consecutive measurements of the cerebral blood flow velocity may be inadequate to assess cerebral oxygenation.
-
Anesthesia and analgesia · Aug 1999
Epidural anesthesia and analgesia are not impaired after dural puncture with or without epidural blood patch.
Previous reports have noted a decrease in the success of subsequent epidural anesthesia and analgesia in patients who have undergone prior dural puncture with or without an epidural blood patch. Our retrospective study evaluated the success of epidural anesthesia and analgesia in all patients at the Mayo Clinic who had received a prior epidural blood patch over a 12-yr period. Each epidural blood patch patient was matched to two patients undergoing epidural anesthesia after previous dural puncture (without epidural blood patch) and to two patients undergoing epidural anesthesia after previous epidural anesthetic (without dural puncture/blood patch). These patients were matched for the duration of time between the initial procedure and subsequent epidural anesthetic and the indication (surgery, labor analgesia, postoperative analgesia) for which the subsequent epidural was performed. Subsequent epidural anesthesia was successful in 28 of 29 (96.6%, exact 95% CI 82.2%-99.9%) patients who had undergone prior blood patch, 55 of 58 (94.8%, 85.6%-98.9%) patients with a history of dural puncture, and 55 of 58 (94.8%, 85.6%-98.9%) patients who had had previous epidural anesthesia. There was no significant difference in the success rate of subsequent epidural anesthesia among groups. We conclude that prior dural puncture, with or without epidural blood patch, does not affect the success rate of subsequent epidural anesthesia. ⋯ Patients with postdural puncture headache should not be denied the benefits of an epidural blood patch because of concerns about the impairment of subsequent epidural anesthetics. The success rate of subsequent epidural anesthesia and analgesia in patients who have undergone dural puncture with or without epidural blood patch is similar to that of patients who have undergone two prior epidural anesthetics.
-
Anesthesia and analgesia · Aug 1999
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialThe effects of rapacuronium on histamine release and hemodynamics in adult patients undergoing general anesthesia.
Neuromuscular blocking drugs may have variable effects on heart rate (HR) and blood pressure. Rapacuronium is a rapid-acting, steroidal-derived neuromuscular blocking drug whose hemodynamic effects have not been characterized. We studied the effects of 1, 2, and 3 mg/kg rapacuronium on histamine release, HR, and blood pressure in 47 ASA physical status II or III adult patients after the induction of anesthesia with etomidate/fentanyl/N2O. Plasma histamine concentrations were measured before induction and immediately before and 1, 3, and 5 min after the rapid administration of rapacuronium. Mean arterial pressure (MAP) decreased after rapacuronium administration, but there were no significant differences among the groups for changes in HR or MAP, and there was no correlation between changes in MAP or HR and increases in histamine levels. There were no changes in HR or MAP among five patients who had significant (> or = 1 ng/mL) increases in histamine from baselin. Seven patients had bronchospasm without increases in plasma histamine levels. Rapacuronium 2-3 mg/kg increased plasma histamine levels. However, clinically significant histamine-related sequelae did not occur in this population with 1- to 3-mg/kg doses of rapacuronium, and cardiovascular changes were not directly correlated with histamine release. Rapacuronium administration can produce hypotension via mechanisms that do not seem to be related to histamine release. ⋯ Rapacuronium, a new steroidal-derived muscle relaxant, may release histamine and produce slight changes in blood pressure and heart rate after administration.
-
Anesthesia and analgesia · Aug 1999
Randomized Controlled Trial Comparative Study Clinical TrialPropofol versus propofol-ketamine sedation for retrobulbar nerve block: comparison of sedation quality, intraocular pressure changes, and recovery profiles.
We compared sedation quality, intraocular pressure (IOP) changes, and recovery profiles in patients who received propofol or propofol-ketamine sedation during placement of the retrobulbar nerve block (RBB). Seventy elderly patients undergoing cataract extraction according to a prospective, randomized, double-blinded protocol were preoperatively evaluated with a Mini-Mental State examination and baseline IOP. A hypnotic dose was provided with either propofol (Group P) or a propofol-ketamine (Group PK) combination. The IOP measurement was repeated, and the surgeon initiated the RBB. Supplemental study drug was given if needed. The level of sedation was considered acceptable if the patient exhibited minimal or no movement and grimacing with needle insertion. Patients were evaluated in terms of quality of sedation, cardiopulmonary stability, and recovery profile. Compared with patients in Group P, patients in Group PK had a significantly faster onset of acceptable sedation (Group P 235 +/- 137 s versus Group PK 164 +/- 67 s) and required significantly less supplemental sedation (Group P 1.1 +/- 1.9 mL versus Group PK 0.15 +/- 0.3 mL). Additionally, none of the Group PK patients required ventilatory assistance, but two patients in Group P required assisted mask ventilation. In conclusion, the addition of ketamine (13.2 +/- 3.3 mg) to propofol (44 +/- 11 mg) decreased the hypnotic requirement and improved the quality of sedation without prolonging recovery. ⋯ Anesthesiologists frequently perform retrobulbar blocks while simultaneously providing sedation. Using ketamine to supplement propofol sedation provided a faster onset and improved the quality of sedation during the retrobulbar block procedure.
-
Anesthesia and analgesia · Aug 1999
Randomized Controlled Trial Comparative Study Clinical TrialComparison of ramosetron and granisetron for preventing postoperative nausea and vomiting after gynecologic surgery.
In a prospective, randomized, double-blinded study, we evaluated the efficacy of granisetron and ramosetron for preventing postoperative nausea and vomiting (PONV) in major gynecologic surgery. One hundred twenty patients, ASA physical status I or II, aged 23-65 yr, received i.v. granisetron 2.5 mg or ramosetron 0.3 mg (n = 60 each) at the end of surgery. A standard general anesthetic technique and postoperative analgesia were used. The incidence of a complete response, defined as no PONV and no need for another rescue medication, 0-3 h after anesthesia was 87% with granisetron and 90% with ramosetron; the corresponding incidence 3-24 h after anesthesia was 85% and 90%; the corresponding incidence 24-48 h after anesthesia was 70% and 92% (P < 0.05). No clinically serious adverse events due to the drugs were observed in any of the groups. In conclusion, prophylactic therapy with ramosetron is more effective than granisetron for the longterm prevention of PONV after major gynecologic surgery. ⋯ We compared the efficacy of granisetron and ramosetron for preventing postoperative nausea and vomiting in major gynecologic surgery. Prophylactic therapy with ramosetron was more effective than granisetron for preventing postoperative nausea and vomiting 24-48 h after anesthesia.