Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialPropofol-sufentanil anesthesia for thyroid surgery: optimal concentrations for hemodynamic and electroencephalogram stability, and recovery features.
Hypnotics and opioids interact synergistically to block responses to surgery and different dose combinations may be used to provide adequate anesthesia. In this study, we sought to determine the optimal concentrations of propofol and sufentanil, given by target-controlled infusions, to ensure hemodynamic stability, adequate hypnosis (assessed by electroencephalogram bispectral index), and fast recovery for a moderately painful operation. Forty-five patients, ASA physical status I or II, undergoing thyroidectomy, were randomly assigned to a sufentanil target concentration (STC) that was maintained throughout surgery (0.1, 0.2, or 0.3 ng/mL). The propofol target concentration was adjusted to keep mean arterial blood pressure within 30% of a reference value, and bispectral index between 40 and 60. Adequate anesthesia was obtained in all groups. Hypertension and clinically dangerous movements were more frequent with the small STC, and hypotension requiring treatment was more frequent with the large STC. Propofol target concentration during surgery decreased significantly with increasing STC (median at thyroid removal 5.0, 4.0, and 2.5 microg/mL, respectively) as well as the propofol consumption (740, 668, 474 mg/h). The 0.3 ng/mL STC significantly delayed the return of spontaneous breathing. ⋯ Given as a target-controlled infusion for thyroid surgery, sufentanil 0.3 ng/mL for intubation and 0.2 ng/mL during surgery, combined with propofol 4 microg/mL (corresponding to a maintenance infusion rate of approximately 7-10 mg. kg(-1). h(-1)), is recommended to ensure both optimal intraoperative stability and fast recovery.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialThe dose-sparing effect of clonidine added to ropivacaine for labor epidural analgesia.
To determine the effects of clonidine with ropivacaine during epidural labor analgesia, we studied 66 nulliparous women in early active labor. Women were randomized to receive ropivacaine 0.1% 8 mL plus 75 microg of clonidine (Group 1), ropivacaine 0.2% 8 mL plus 0.5 mL of NaCl 0.9% (Group 2), or ropivacaine 0.2% 8 mL plus 75 microg of clonidine (Group 3) 5 min after a bupivacaine 7.5 mg with epinephrine 15 microg test dose. Upon request, additional analgesia with ropivacaine 0.1% 8 mL followed by ropivacaine 0.2% 8 mL/h was administered. With clonidine, duration of analgesia was increased (132 +/- 48 min [Group 1] and 154 +/- 42 min [Group 3] versus 91 +/- 44 min [Group 2]; P < 0.05), and total ropivacaine dose over the first 4 h was significantly reduced (40.5 +/- 15 mg [Group 1] and 47.0 +/- 16 mg [Group 3] versus 72.5 +/- 18 mg [Group 2]; P < 0.01). The incidence of more profound motor block was more frequent in Group 2 (P < 0.05). Although there was a trend for more women receiving clonidine to require ephedrine for treatment of hypotension, this did not seem to have an impact on fetal outcome or incidence of cesarean deliveries for nonreassuring fetal heart rate tracings. This study demonstrates the dose-sparing effect of clonidine when added to ropivacaine. ⋯ The effect of adding 75 microg of clonidine to ropivacaine for epidural labor analgesia was studied. Clonidine increased analgesia duration and produced dose sparing compared with ropivacaine alone. Despite a tendency for hypotension in women receiving clonidine, there was no apparent effect on delivery mode or neonatal outcome.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialProphylactic IM small-dose phenylephrine blunts spinal anesthesia-induced hypotensive response during surgical repair of hip fracture in the elderly.
In a double-blinded, placebo-controlled, randomized study, we evaluated the effect of prophylactic IM phenylephrine at doses of 1.5 and 3 mg on hyperbaric tetracaine spinal anesthesia-induced hypotension in 90 normotensive and hypertensive patients aged >65 yr undergoing surgery for hip fracture. Thirty normotensive patients received 1.5 or 3 mg of phenylephrine IM (N/P-1.5 and N/P-3.0 groups; n = 15 in each), whereas controls received saline (N/C group; n = 15), and 45 hypertensive patients were treated in a similar manner (H/P-1.5, H/P-3.0, and H/C groups; n = 15 in each). All groups had a peak sensory block height of T9, with a range of T8 to T10. The incidence of hypotension (>25% decrease in mean arterial blood pressure [MAP] from baseline) was significantly lower in the patients who received phenylephrine 1.5 or 3 mg than in the controls, both in the normotensive and hypertensive groups (P < 0.01). The N/P-3.0 and N/P-1.5 groups and the H/P-3.0 group had significantly lower percentage reductions in MAP (P < 0.05) and required significantly smaller doses of rescue IV ephedrine (P < 0.05) than did the N/C group or the H/C group. The H/P-1.5 group also required significantly less rescue IV ephedrine (P < 0.05), although it was not sufficient to significantly attenuate the percentage decrease in MAP compared with that in the H/C group. Bradycardia (heart rate <50 bpm) as an adverse effect after IM administration of phenylephrine was not observed in any of the groups. Hypertension (MAP >20% increase from baseline) after medication occurred in the N/P-3.0 and H/P-3.0 groups, but not in the N/P-1.5 and H/P-1.5 groups. We conclude that prophylactic IM injection of 1.5 mg of phenylephrine is a safe (defined as the inhibition of bradycardia and hypertension) and effective means of reducing the incidence of hypotension associated with spinal anesthesia in normotensive and hypertensive elderly patients. ⋯ We evaluated the efficacy and safety of small-dose IM phenylephrine for prophylaxis against spinal anesthesia-induced hypotension in normotensive and hypertensive elderly patients. Phenylephrine 1.5 mg IM was effective for reducing the incidence of hypotension and avoided adverse effects.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Comparative Study Clinical TrialBispectral index in patients with target-controlled or manually-controlled infusion of propofol.
In this prospective, randomized study we compared bispectral index (BIS), hemodynamics, time to extubation, and the costs of target-controlled infusion (TCI) and manually-controlled infusion (MCI) of propofol. Forty patients undergoing first-time implantation of a cardioverter-defibrillator were included. Anesthesia was performed with remifentanil (0.2-0.3 micro g. kg(-1). min(-1)) and propofol. Propofol was used as TCI (plasma target concentration, 2.5-3.5 micro g/mL; n = 20) or MCI (3.0-4.0 mg. kg(-1). h(-1); n = 20). BIS, heart rate, and arterial blood pressure were measured at six data points: T1, before anesthesia; T2, after intubation; T3, after skin incision; T4, after first defibrillation; T5, after third defibrillation; and T6, after extubation. There were no significant hemodynamic differences between the two groups. BIS was significantly lower at T3 and T4 in the TCI group than in the MCI group. The mean dose of propofol was larger in TCI patients (5.8 +/- 1.4 mg. kg(-1). h(-1)) than in the MCI patients (3.7 +/- 0.6 mg. kg(-1). h(-1)) (P < 0.05), whereas doses of remifentanil did not differ. Time to extubation did not differ between the two groups (TCI, 13.7 +/- 5.3 min; MCI, 12.3 +/- 3.5 min). One patient in the MCI group had signs of intraoperative awareness without explicit memory after first defibrillation (BIS before shock, 49; after shock, 83). Costs were significantly less in the MCI group (34.83 US dollars) than in the TCI group (39.73 US dollars). BIS failed to predict the adequacy of anesthesia for the next painful stimulus. ⋯ In this prospective, randomized study, bispectral index (BIS), hemodynamics, time to extubation, and costs of target-controlled infusion (TCI) and manually-controlled infusion of propofol were compared. TCI increased the amount of propofol used. BIS failed to predict the adequacy of anesthesia for the next painful stimulus.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialPrehospital analgesia with acupressure in victims of minor trauma: a prospective, randomized, double-blinded trial.
Untreated pain during the transportation of patients after minor trauma is a common problem in emergency medicine. Because paramedics usually are not allowed to perform invasive procedures or to give drugs for pain treatment, a noninvasive, nondrug-based method would be helpful. Acupressure is a traditional Chinese treatment for pain that is based on pain relief followed by a short mechanical stimulation of specific points. Consequently, we tested the hypothesis that effective pain therapy is possible by paramedics who are trained in acupressure. In a double-blinded trial we included 60 trauma patients. We randomly assigned them into three groups ("true points," "sham-points," and "no acupressure"). An independent observer, blinded to the treatment assignment, recorded vital variables and visual analog scales for pain and anxiety before and after treatment. At the end of transport, we asked for ratings of overall satisfaction. For statistical evaluation, one-way analysis of variance and the Scheffé F test were used. P < 0.05 was considered statistically significant. Morphometric and demographic data and potential confounding factors such as age, sex, pain, anxiety, blood pressure, and heart rate before treatment did not differ among the groups. At the end of transport we found significantly less pain, anxiety, and heart rate and a greater satisfaction in the "true points" groups (P < 0.01). Our results show that acupressure is an effective and simple-to-learn treatment of pain in emergency trauma care and leads to an improvement of the quality of care in emergency transport. We suggest that this technique is easy to learn and risk free and may improve paramedic-based rescue systems. ⋯ We tested, in a double-blinded manner, the hypothesis that acupressure could be an effective pain therapy in minor-trauma patients. Our results show that acupressure is an effective and simple-to-learn treatment of pain in emergency medical care and can improve the quality of care.