Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Comparative Study Clinical TrialSmall-dose intrathecal lidocaine versus ropivacaine for anorectal surgery in an ambulatory setting.
Spinal anesthesia with the local anesthetic lidocaine has come under scrutiny because it is associated with transient neurologic symptoms (TNS). We designed this study to prospectively compare the efficacy of ropivacaine as an alternative to lidocaine in patients undergoing elective outpatient anorectal procedures. Seventy-two patients were randomized to receive either hyperbaric lidocaine 25 mg with fentanyl 20 microg (n = 37) or hyperbaric ropivacaine 4 mg with fentanyl 20 microg (n = 35). Patients were examined for motor block, sensory block, and block duration. Patients were contacted at 24, 48, 72, and 168 h and questioned about their perceptions of pain after the spinal with specific questions designed to diagnose TNS. There were no patients with TNS in either group. There was no significant difference between the lidocaine and ropivacaine groups in any of the outcomes studied. In conclusion, intrathecal hyperbaric small-dose ropivacaine with fentanyl is an acceptable anesthetic for anorectal surgery. ⋯ In this prospective trial, small-dose ropivacaine with fentanyl was as effective as small-dose lidocaine with fentanyl for anorectal procedures in the ambulatory setting.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Comparative Study Clinical TrialSevoflurane provides faster recovery and postoperative neurological assessment than isoflurane in long-duration neurosurgical cases.
Sevoflurane (SEVO) provides faster emergence than isoflurane (ISO). This advantage is thought to magnify with increased duration of exposure. In addition, SEVO has several of the characteristics of an ideal neuroanesthetic. We designed a prospective, randomized, double-blinded study to compare the recovery profile of SEVO versus ISO in neurosurgery. Sixty patients undergoing intracranial surgery were enrolled. They were randomized to receive SEVO or ISO in 40% oxygen as part of a balanced anesthetic regimen. The anesthetic concentration (0.5 to 1.0 minimum alveolar anesthetic concentration [MAC]) was adjusted to maintain mean arterial blood pressure within 20% of the preinduction baseline. At the end of the surgery, neuromuscular blockade was reversed, anesthetics were discontinued without prior tapering, and fresh gas flow was increased to 10 L/min. Recovery end-points were measured as the time from closure of the anesthetic vaporizer. Mean MAC-hours were identical in both groups (4.7). Patients in the SEVO group demonstrated a shorter time to emergence (P = 0.02) and for response to command (squeeze hand, P = 0.03; move feet, P = 0.01). Patients in the SEVO group obtained a Glasgow coma scale score of >/=10 5 min before patients in the ISO group (P = 0.04). Obtaining an early neurological examination can be critical in neurosurgical patients. The observed difference in emergence between SEVO and ISO could therefore be of clinical importance. ⋯ The low-solubility anesthetic, sevoflurane, provides faster recovery and postoperative neurological assessment than isoflurane after long-duration (4.7 MAC-h) intracranial surgery.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Clinical TrialCaudal anesthesia in children: effect of volume versus concentration of bupivacaine on blocking spermatic cord traction response during orchidopexy.
In this study we compared the intensity and level of caudal blockade when two different volumes and concentrations of a fixed dose of bupivacaine were used. Fifty children, 1-6 yr old, undergoing unilateral orchidopexy received a caudal block with a fixed 2 mg/kg dose of bupivacaine immediately after the induction. Group 1 (n = 23) received 0.8 mL/kg of 0.25% bupivacaine, whereas Group 2 (n = 27) received 1.0 mL/kg of 0.2% bupivacaine. Epinephrine 1:400,000 and 0.1 mL of sodium bicarbonate per 10 mL of local anesthetic solution were added. There were no statistically significant differences between the two groups in their anesthesia, surgery, recovery, and discharge times. Fifteen patients (65.2%) in Group 1 required an increase in inspired halothane concentration to block hemodynamic and/or ventilatory response during spermatic cord traction, as compared with 8 patients (29.6%) in Group 2 (P = 0.022). In the recovery room, four (17.4%) patients in Group 1 required rescue treatment with fentanyl, versus two (7.4%) in Group 2 (P = 0.372). In children undergoing orchidopexy, a caudal block with a larger volume of dilute bupivacaine is more effective than a smaller volume of the standard 0.25% solution in blocking the peritoneal response during spermatic cord traction, with no change in the quality of postoperative analgesia. ⋯ In children undergoing orchidopexy, a caudal block with a larger volume of dilute bupivacaine is more effective than a smaller volume of the more concentrated solution in blocking the peritoneal response during spermatic cord traction, with no change in the quality of postoperative analgesia.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Clinical TrialThe effect of the addition of epinephrine on early systemic absorption of epidural ropivacaine in humans.
The addition of epinephrine to ropivacaine has not been recommended because ropivacaine has intrinsic vasoconstrictor properties. However, few pharmacokinetic data are available on the addition of epinephrine to epidural ropivacaine in humans. In this prospective, double-blinded study, we randomized patients having elective abdominal hysterectomy to receive epidural ropivacaine 1.5 mg/kg, diluted in 15 mL, either with (epinephrine group, n = 12) or without (plain group, n = 12) epinephrine 5 microg/mL and then measured arterial and venous plasma concentrations of ropivacaine at intervals up to 180 min. We found that arterial and venous plasma ropivacaine concentrations were smaller in the epinephrine group compared with the plain group in the first 60 min after the drug administration (P < 0.01). Mean (+/- SD) maximum total plasma ropivacaine concentration was smaller in the epinephrine group (arterial, 0.92 +/- 0.32 microg/mL; venous, 0.82 +/- 0.33 microg/mL) compared with the plain group (1.31 +/- 0.39 microg/mL and 1.31 +/- 0.50 microg/mL, respectively; P = 0.01). Time to maximum total plasma ropivacaine concentration was not significantly different between groups (mean +/- SD; arterial, 16 +/- 2 min; venous, 23 +/- 2 min in the epinephrine group versus 9 +/- 2 min and 12 +/- 3 min, respectively, in the plain group; P = 0.08). Arterial plasma ropivacaine concentrations were larger than venous concentrations during the first hour (P < 0.01); the arterio-venous difference decreased exponentially, and the rate and magnitude of this decrease was unaffected by epinephrine. We conclude that the addition of epinephrine 5 microg/mL to ropivacaine reduced the early systemic plasma concentrations of ropivacaine after epidural injection and may be useful for decreasing the risk of toxicity from systemic absorption of epidural ropivacaine. ⋯ The addition of epinephrine 5 microg/mL to epidural ropivacaine reduced the systemic arterial and venous plasma concentrations of ropivacaine in the first hour and the maximum plasma concentration of ropivacaine. Epinephrine may be a useful additive for reducing the risk of systemic toxicity when large doses of ropivacaine are given epidurally.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Comparative Study Clinical TrialOndansetron and dolasetron provide equivalent postoperative vomiting control after ambulatory tonsillectomy in dexamethasone-pretreated children.
In this prospective, randomized, double-blinded, placebo-controlled study, we compared the incidence of emesis and 48-h recovery profiles after a single dose of preoperative ondansetron versus dolasetron in dexamethasone-pretreated children undergoing ambulatory tonsillectomy. One-hundred-forty-nine children, 2-12 yr old, ASA physical status I and II, completed the study. All children received standardized perioperative care, including premedication, surgical and anesthetic techniques, IV fluids, analgesics, and rescue antiemetic medications. Patients were randomized to receive ondansetron 0.15 mg/kg, maximum 4 mg (Group 1); dolasetron 0.5 mg/kg, maximum 25 mg (Group 2); or saline placebo (Group 3) IV before the initiation of surgery. In addition, all patients received dexamethasone 1 mg/kg (maximum 25 mg). Rescue antiemetics were administered for two or more episodes of retching/vomiting. The incidence of retching/vomiting before home discharge did not differ between the ondansetron and dolasetron groups and was significantly less frequent compared with the placebo group (10%, Group 1; 8%, Group 2; 30%, Group 3). Similar results were obtained at 24-48 h after discharge (6%, Groups 1 and 2; 18%, Group 3). The need for rescue antiemetics administered after the second retching/vomiting episode was significantly less in Groups 1 (4%) and 2 (6%) compared with Group 3 (22%) before home discharge. The complete response rate, defined as no retching/vomiting and no antiemetic for 48 h, was significantly increased in Groups 1 (76%) and 2 (74%) compared with Group 3 (44%). The antiemetic efficacy of prophylactic ondansetron and dolasetron was comparable in dexamethasone-pretreated children undergoing ambulatory tonsillectomy. ⋯ The efficacy of a single dose of prophylactic ondansetron versus dolasetron in conjunction with dexamethasone was studied on posttonsillectomy retching/vomiting and 48-h recovery in children 2-12 yr old. Compared with placebo, ondansetron and dolasetron produced comparable reductions in the incidence of retching/vomiting and the need for rescue antiemetics.