Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2001
Randomized Controlled Trial Comparative Study Clinical TrialHyperbaric spinal ropivacaine for cesarean delivery: a comparison to hyperbaric bupivacaine.
We evaluated the clinical efficacy and safety of spinal anesthesia with 0.5% hyperbaric ropivacaine compared with 0.5% hyperbaric bupivacaine for elective cesarean delivery. Sixty healthy, full-term parturients were randomly assigned to receive either 12 mg of 0.5% hyperbaric bupivacaine or 18 mg of 0.5% hyperbaric ropivacaine intrathecally. There were no significant differences in demographic or surgical variables or neonatal outcomes between groups. Onset time of sensory block to T10 or to peak level was later in the Ropivacaine group (P < 0.05). The median (range) peak level of analgesia was T3 (T1-5) in the Bupivacaine group and T3 (T1-4) in the Ropivacaine group. Time for sensory block to recede to T10 did not differ between groups. Duration of sensory block was shorter in the Ropivacaine group (188.5 +/- 28.2 min vs 162.5 +/- 20.2 min; P < 0.05). Complete motor block of the lower extremities was obtained in all patients. Ropivacaine also produced a shorter duration of motor blockade than bupivacaine (113.7 +/- 18.6 min vs 158.7 +/- 31.2 min; P < 0.000). The intraoperative quality of anesthesia was excellent and similar in both groups. Side effects did not differ between groups. Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12 mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery ⋯ Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery.
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Anesthesia and analgesia · Jul 2001
Randomized Controlled Trial Clinical TrialUnderstanding the mechanisms by which isoflurane modifies the hyperglycemic response to surgery.
We studied the effect of anesthesia on the kinetics of perioperative glucose metabolism by using stable isotope tracers. Twenty-three patients undergoing cystoprostatectomy were randomly assigned to receive epidural analgesia combined with general anesthesia (n = 8), fentanyl and midazolam anesthesia (n = 8), or inhaled anesthesia with isoflurane (n = 7). Whole-body glucose production and glucose clearance were measured before and during surgery. Glucose clearance significantly decreased during surgery independent of the type of anesthesia. Epidural analgesia caused a significant decrease in glucose production from 10.2 +/- 0.4 to 9.0 +/- 0.4 micromol. kg(-1). min(-1) (P < 0.05), whereas the plasma glucose concentration was not altered (before surgery, 5.0 +/- 0.2 mmol/L; during surgery, 5.2 +/- 0.1 mmol/L). Glucose production did not significantly change during fentanyl/midazolam anesthesia (before surgery, 10.5 +/- 0.5 micromol. kg(-1). min(-1); during surgery, 10.1 +/- 0.5 micromol. kg(-1). min(-1)), but plasma glucose concentration significantly increased from 4.8 +/- 0.1 mmol/L to 5.3 +/- 0.2 mmol/L during surgery (P < 0.05). Isoflurane anesthesia caused a significant increase in plasma glucose concentration (from 5.2 +/- 0.1 mmol/L to 7.2 +/- 0.5 mmol/L) and glucose production (from 10.8 +/- 0.5 micromol. kg(-1). min(-1) to 12.4 +/- 1.0 micromol. kg(-1). min(-1)) (P < 0.05). Epidural analgesia prevented the hyperglycemic response to surgery by a decrease in glucose production. The increased glucose plasma concentration during fentanyl/midazolam anesthesia was caused by a decrease in whole-body glucose clearance. The hyperglycemic response observed during isoflurane anesthesia was a consequence of both impaired glucose clearance and increased glucose production. ⋯ Epidural analgesia combined with general anesthesia prevented the hyperglycemic response to surgery by decreasing endogenous glucose production. The increased glucose plasma concentration in patients receiving fentanyl/midazolam anesthesia was caused by a decrease in whole-body glucose clearance. The hyperglycemic response observed during inhaled anesthesia with isoflurane was a consequence of both impaired glucose clearance and increased glucose production.
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Anesthesia and analgesia · Jul 2001
Randomized Controlled Trial Clinical TrialResting esophageal sphincter pressures and deglutition frequency in awake subjects after oropharyngeal topical anesthesia and laryngeal mask device insertion.
We investigated the effects of oropharyngeal topical anesthesia and placement of the standard (LMA) and the ProSeal (PLMA) laryngeal mask airway on resting gastroesophageal barrier pressure (GEBP), upper esophageal sphincter pressure (UESP), and deglutition frequency in awake subjects. Each subject was studied on 2 consecutive days: 1 day with the LMA and the other with the PLMA, in random order. GEBP and UESP were measured between deglutitions by using a pull-through technique in five sequential conditions: 1) after acclimatization to the manometer, 2) after topical anesthesia, 3) after the LMA or PLMA was self-inserted and the cuff inflated with either 10 or 30 mL of air in random order, 4) after the cuff volume was adjusted to the other randomized volume, and 5) after LMA or PLMA removal. Deglutition frequency was determined between pressure measurements by using a neck microphone. UESP was always larger than GEBP (P < 0.001 for all). Topical anesthesia had no influence on GEBP, UESP, or deglutition frequency. LMA and PLMA placement did not influence GEBP or UESP, but deglutition frequency was higher (P < 0.02 for all). GEBP and UESP did not vary between devices for any condition. Cuff volume did not influence GEBP or UESP. Deglutition frequency was more frequent for the LMA than the PLMA at a 30-mL cuff volume (P = 0.008). We conclude that resting GEBP and UESP are unaffected by oropharyngeal topical anesthesia and the LMA or PLMA in awake subjects, but that deglutition frequency is increased by the LMA or PLMA. This may have implications for the incidence of regurgitation in these situations. ⋯ Resting gastroesophageal barrier pressure and upper esophageal sphincter pressure are unaffected by oropharyngeal topical anesthesia and laryngeal mask devices in awake subjects, but deglutition frequency is increased by laryngeal mask devices. This may have implications for the incidence of regurgitation in these situations.
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Anesthesia and analgesia · Jul 2001
Comparative Study Clinical TrialFast-tracking after outpatient laparoscopy: reasons for failure after propofol, sevoflurane, and desflurane anesthesia.
In this study, although 41%-94% of the patients were fast-track eligible after laparoscopic surgery, only 35%-53% of the patients actually bypassed the postanesthesia care unit (PACU) because of anesthetic-related factors and surgical complications. Residual sedation was the most common anesthetic-related cause of failure to bypass thePACU.
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Anesthesia and analgesia · Jul 2001
Comparative Study Clinical TrialA comparison of the transient hyperemic response test and the static autoregulation test to assess graded impairment in cerebral autoregulation during propofol, desflurane, and nitrous oxide anesthesia.
The transient hyperemic response (THR) test has been used to assess cerebral autoregulation in anesthesia and intensive care. To date it has not been compared with the static autoregulation test for assessing graded changes in cerebral autoregulation. We compared the two tests during propofol, desflurane, and nitrous oxide anesthesia. Seven subjects were studied. For the THR test, changes in the middle artery blood flow velocity were assessed during and after a 10-s compression of the ipsilateral common carotid artery. Two indices of autoregulation--THR ratio (THRR) and strength of autoregulation (SA)--were calculated. For the test of static autoregulation, changes in the middle cerebral artery flow velocity after a phenylephrine-induces increase in mean arterial pressure were assessed, and the static rate of regulation (sROR) was calculated. The tests were performed before induction and after equilibrium at 0.5 minimum alveolar anesthetic concentration (MAC) and then at 1.5 MAC of desflurane. THRR, SA and sROR decreased significantly (P < 0.001) at 0.5 MAC and then at 1.5 MAC desflurane. CHanges in THRR and SA reflected the changes in sROR with a sensitivity of 100%. ⋯ When compared with the established test of static autoregulation, the transient hyperemic response test provides a valid method for assessing graded impairment in cerebral autoregulation.