Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2004
Randomized Controlled Trial Clinical TrialProphylactic phenylephrine infusion for preventing hypotension during spinal anesthesia for cesarean delivery.
In a randomized, double-blinded, controlled trial, we investigated the prophylactic infusion of IV phenylephrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. Immediately after intrathecal injection, phenylephrine was infused at 100 microg/min (n = 26) for 3 min. From that point until delivery, phenylephrine was infused at 100 microg/min whenever systolic arterial blood pressure (SAP), measured each minute, was less than baseline. A control group (n = 24) received IV bolus phenylephrine 100 microg after each measurement of SAP <80% of baseline. Phenylephrine infusion decreased the incidence (6 [23%] of 26 versus 21 [88%] of 24; P < 0.0001), frequency, and magnitude (median minimum SAP, 106 mm Hg; interquartile range, 95-111 mm Hg; versus median, 80 mm Hg; range, 73-93 mm Hg; P < 0.0001) of hypotension compared with control. Heart rate was significantly slower over time in the infusion group compared with the control group (P < 0.0001). Despite a large total dose of phenylephrine administered to the infusion group compared with the control group (median, 1260 microg; interquartile range, 1010-1640 microg; versus median, 450 microg; interquartile range, 300-750 microg; P < 0.0001), umbilical cord blood gases and Apgar scores were similar. One patient in each group had umbilical arterial pH <7.2. Prophylactic phenylephrine infusion is a simple, safe, and effective method of maintaining arterial blood pressure during spinal anesthesia for cesarean delivery. ⋯ In patients receiving spinal anesthesia for elective cesarean delivery, a prophylactic infusion of phenylephrine 100 microg/min decreased the incidence, frequency, and magnitude of hypotension with equivalent neonatal outcome compared with a control group receiving IV bolus phenylephrine.
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Anesthesia and analgesia · Mar 2004
Randomized Controlled Trial Clinical TrialThe influence of ambulation time on the incidence of transient neurologic symptoms after lidocaine spinal anesthesia.
The cause of transient neurologic symptoms (TNSs) after lidocaine spinal anesthesia remains unclear. It has been proposed that early ambulation after spinal anesthesia contributes to the development of TNSs. We evaluated the influence of ambulation time on the occurrence of TNSs after spinal anesthesia with 50 mg of 2% plain lidocaine for knee arthroscopy. One-hundred-twenty patients undergoing knee arthroscopy (ASA physical status 1-2) were randomized into 3 groups, i.e., early (Group E), 6-h (Group 6-h), or late ambulation (Group L) groups. In Group E, ambulation was allowed as early as possible after regression of spinal block (on average 229 +/- 21 min; range, 135-247 min). In Group 6-h, the patients remained in bed for approximately 6 h after the block and in Group L until the next morning. The patient groups were comparable with respect to demographic, anesthetic, and surgical variables. The overall incidence of TNSs was 16%. TNSs occurred in 3 patients of Group E (7.5%), in 11 patients of Group 6-h (28%), and in 5 patients of Group L (13%). No significant differences were detected between the patients with and without TNSs. Early ambulation was not found to be a risk factor for TNSs after spinal anesthesia with 50 mg of 2% lidocaine. ⋯ This study shows that early ambulation time does not increase the incidence of transient neurologic symptoms after spinal anesthesia with 50 mg of 2% lidocaine for elective knee arthroscopy.
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Anesthesia and analgesia · Mar 2004
Randomized Controlled Trial Comparative Study Clinical TrialDextromethorphan-associated epidural patient-controlled analgesia provides better pain- and analgesics-sparing effects than dextromethorphan-associated intravenous patient-controlled analgesia after bone-malignancy resection: a randomized, placebo-controlled, double-blinded study.
Pain after bone malignancy surgery is intense and requires large amounts of analgesics. The augmented antinociceptive effects of dextromethorphan (DM), a N-methyl-D-aspartate receptor antagonist, were demonstrated previously. We assessed the use of postoperative patient-controlled epidural analgesia (PCEA) or IV patient-controlled analgesia (PCA) in patients undergoing surgery for bone malignancy under standardized combined general and epidural anesthesia with or without DM. Patients (n = 120) were randomly allocated to receive PCEA (ropivacaine 3.2 mg plus fentanyl 8 microg/dose) or IV-PCA (morphine 2 mg/dose) postoperatively, starting at subjective visual analog scale pain intensity >or=4 of 10 for up to 96 h. Placebo or DM 90 mg orally (30 patients/group/set) was given in a double-blinded manner before surgery and for 2 days afterwards. Diclofenac 75 mg IM was available as a rescue drug. DM patients used PCA and rated their pain >50% less than their placebo counterparts in each set, especially during the first 2 postoperative days (P < 0.01). Hourly and overall maximal pain intensity among PCEA patients was approximately 50% less than in the IV-PCA set (P < 0.01). Diclofenac was used 42% less (P < 0.01) by the PCA-DM patients compared with their placebo counterparts. Seven PCEA-DM and 11 IV-PCA-DM individuals reported having side effects compared with 44 in the PCEA-placebo and the IV-PCA-placebo groups (P < 0.01). Time to first ambulation was similar with both analgesia techniques but shorter among the DM-treated patients compared with the placebo recipients (1.5 +/- 0.8 versus 2.1 +/- 1.1 days, P = 0.02). Thus, DM afforded better pain control and reduced the demand for analgesics, augmented the PCEA effect versus IV-PCA, and was associated with minimal untoward effects in each analgesia set. DM patients ambulated earlier than placebo recipients. ⋯ Patients undergoing bone-malignancy surgery under combined general and epidural anesthesia received randomly patient-controlled epidural analgesia (PCEA) or IV patient-controlled analgesia (PCA) postoperatively and dextromethorphan (DM) 90 mg or placebo double-blindly for 3 days (n = 30/group/set). The DM effect was recorded with minimal untoward effects: it afforded better pain control and reduced the demand for analgesics compared with the placebo, especially when associated with PCEA. DM patients ambulated earlier than placebo recipients.
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Anesthesia and analgesia · Mar 2004
Randomized Controlled Trial Clinical TrialThe effects of different ventilatory settings on pulmonary and systemic inflammatory responses during major surgery.
Mechanical ventilation with high tidal volumes (V(T)) and zero or low positive end-expiratory pressure increased mediator release to inflammatory stimuli or acute lung injury. We studied whether mechanical ventilation modifies the inflammatory responses during major thoracic or abdominal surgery. Sixty-four patients undergoing elective thoracotomy (n = 34) or laparotomy (n = 30) were randomized to receive either mechanical ventilation with V(T) = 12 or 15 mL/kg ideal body weight, respectively, and zero end-expiratory pressure, or V(T) = 6 mL/kg ideal body weight with positive end-expiratory pressure of 10 cm H(2)O. In 62 patients who completed the study, arterial oxygenation was not different between groups. Tumor necrosis factor, interleukin (IL)-1, IL-6, IL-8, IL-10, and IL-12 were determined by cytometric bead array in plasma after 0, 1, 2, and 3 h and in tracheal aspirates after 3 h of mechanical ventilation. Data were log-transformed and analyzed using parametric or nonparametric tests, as indicated. All plasma mediators increased more during abdominal than during thoracic surgery, although the differences were small. However, neither time course nor concentrations of pulmonary or systemic mediators differed between the two ventilatory settings. Our data suggest that the ventilatory settings we studied do not affect inflammatory reactions during major surgery within 3 h. ⋯ In 62 patients undergoing elective major thoracic or abdominal surgery, mechanical ventilation with low tidal volumes and positive end-expiratory pressure or high tidal volumes and zero end-expiratory pressure did not result in different pulmonary or systemic levels of measured inflammatory markers.
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Anesthesia and analgesia · Mar 2004
Clinical TrialThe intubating laryngeal mask airway facilitates tracheal intubation in the lateral position.
Although the difficulty of tracheal intubation in the lateral position has not been systematically evaluated, airway loss during surgery in a laterally positioned patient may have hazardous consequences. We explored whether the intubating laryngeal mask airway (ILMA) facilitates tracheal intubation in patients with normal airway anatomy, i.e., Mallampati grade