Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Comparative Study Clinical TrialComparison of desflurane with isoflurane or propofol in spontaneously breathing ambulatory patients.
Desflurane is a potentially useful anesthetic for ambulatory surgery, but it has had limited evaluation in spontaneously breathing patients. After the induction of anesthesia with propofol and laryngeal mask insertion, 90 patients were randomized to receive isoflurane (0.25%-1%), propofol (50-200 microg x kg(-1) x min(-1)), or desflurane (1.4%-6%) for anesthetic maintenance. Respiratory complications were uncommon; only six patients coughed (three who received isoflurane, one who received propofol, and two who received desflurane), and no anesthetic produced significant respiratory depression. Purposeful movement was significantly more common with propofol (19 patients; 63%) compared with isoflurane (7 patients; 23%) or desflurane (2 patients; 6.7%), but no patient had recall. Emergence times were similar in the isoflurane, propofol, and desflurane groups (5.1 +/- 2.3, 5.6 +/- 3.1, and 4.4 +/- 1.4 min, respectively). Later recovery end points and pain and sedation visual analog scale scores did not differ among groups. Overall, 85 patients (94%) were free from postoperative nausea and vomiting. Desflurane produced few respiratory complications in spontaneously breathing ambulatory patients but offered no improvement in emergence or recovery compared with isoflurane. Propofol also did not reduce recovery times or side effects; however, it was more difficult to maintain an adequate depth of anesthesia. We conclude that neither desflurane nor propofol offered any major advantages over the older anesthetic, isoflurane, under the conditions of our study. ⋯ The new inhaled anesthetic desflurane is acceptable in spontaneously breathing outpatients despite its known ability to irritate the airway. The i.v. anesthetic propofol was associated with more patient movement (without awareness) during surgery. Neither anesthetic conferred any clinically significant advantages over the older inhaled drug, isoflurane.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialThe efficacy of RS-25259, a long-acting selective 5-HT3 receptor antagonist, for preventing postoperative nausea and vomiting after hysterectomy procedures.
We evaluated the safety and efficacy of RS-25259, a potent and long-acting selective 5-HT3 receptor antagonist, for the prevention of postoperative nausea and vomiting (PONV) in women undergoing hysterectomy procedures. In this randomized, double-blind, placebo controlled, dose-ranging study, 218 healthy, consenting women were assigned to one of the six treatment groups: placebo or RS-25259 0.1, 0.3, 1.0, 3.0, or 30 microg/kg. All patients underwent a standardized general anesthetic technique. The study medication was administered i.v. 20-30 min before the end of surgery. During the initial 24-h period after surgery, the incidence of vomiting, the need for rescue antiemetics, the time to the first episode of emesis, and administration of rescue antiemetic medication, as well as a nausea visual analog scale and verbal categorical scale scores were recorded. In addition, recovery times from the end of anesthesia and the incidences of perioperative side effects were noted. Only 30 microg/kg RS-25259 significantly decreased the incidence of vomiting and the requirement for rescue antiemetics. The largest dose of RS-25259 also delayed the time to the first emetic episode and reduced the number of treatment failures. However, no differences were found in the severity of postoperative nausea (versus saline), and postoperative headaches were more common after the administration of RS-25259 0.3-30 microg/kg i.v. In conclusion, RS-25259 30 microg/kg i.v. was effective in reducing the incidence of PONV after major gynecologic surgery, but the occurrence of headaches with the larger doses of RS-25259 is a concern. ⋯ RS-25259, a long-acting 5-HT3 antagonist, was effective in reducing postoperative vomiting only at the largest dose studied (30 microg/kg). However, RS-25259 had no antinausea activity, and the larger doses were associated with an increased incidence of headaches in the postoperative period.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Comparative Study Clinical TrialTopical lidocaine-prilocaine cream (EMLA) versus local infiltration anesthesia for radial artery cannulation.
In a randomized trial, we compared topical anesthesia by a lidocaine-prilocaine cream (EMLA; Laboratorie ASTRA, Manterre, France) with subcutaneous local lidocaine infiltration for radial artery cannulation. Patients included 538 adults scheduled for coronary angiography using a radial approach. EMLA was applied 2 h before radial cannulation, and lidocaine infiltration was performed 5 min before cannulation. The primary end point was pain as assessed by a verbal numerical scale (0 = no pain, 10 = extreme pain). Pain was less severe in the EMLA group than in the lidocaine infiltration group (Score of 2 vs 7; P = 0.0001). Additional lidocaine infiltration was required significantly less frequently in the EMLA group (relative risk 0.19). The failure rate of cannulation was significantly lower in the EMLA group (relative risk 0.38), and insertion time was shorter (4 versus 6 min). We conclude that EMLA, compared with lidocaine infiltration, reduces pain associated with radial artery cannulation and improves the success rate of the procedure. Routine application of EMLA should be performed in awake patients 2 h before radial artery cannulation. ⋯ In a randomized trial, we compared topical anesthesia by a lidocaine-prilocaine cream (EMLA) with subcutaneous local lidocaine infiltration for radial artery cannulation in 538 adults patients. EMLA reduced pain associated with radial artery cannulation and improved the success rate of the procedure.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialThe influence of epidural needle bevel orientation on spread of sensory blockade in the laboring parturient.
Both asymmetrical sensory blockade and dural puncture are undesirable outcomes of epidural analgesia. Identifying the epidural space with the needle bevel oriented parallel to the longitudinal axis of the patient's back limits the risk of headache in the event of dural puncture. However, rotating the bevel to direct a catheter cephalad may risk dural puncture. We prospectively studied the effects of needle rotation on the success of labor epidural analgesia and on the incidence of dural puncture. One hundred sixty ASA physical status I or II laboring parturients were randomly assigned to one of four groups. The epidural space was identified with the bevel of an 18-gauge Hustead needle directed to the patient's left. It was then rotated as follows: Group 0 = no rotation, final bevel orientation left (n = 39); Group 90 = rotation 90 degrees clockwise, bevel cephalad (n = 43); Group 180 = rotation 180 degrees clockwise, bevel right (n = 36); Group 270 = rotation 270 degrees clockwise, bevel caudad (n = 42). A single-orifice catheter was inserted 3 cm, and analgesia was induced in a standardized fashion. Dural puncture was evenly distributed among the groups (4.4%). There were more dermatomal segments blocked, fewer one-sided blocks, and more patients comfortable at 30 min with the needle bevel directed cephalad. Using a catheter inserted through a needle oriented in the cephalad direction increases the success of epidural analgesia. ⋯ This prospective study shows that an epidural catheter inserted through a needle oriented in the cephalad direction increases the success of labor analgesia in the parturient. Carefully rotating the needle cephalad does not increase the risk of dural puncture, intravascular catheters, or failed blocks.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialTranexamic acid and aprotinin reduce postoperative bleeding and transfusions during primary coronary revascularization.
We evaluated the blood conservation effects of tranexamic acid (TA) or aprotinin administered before and during cardiopulmonary bypass (CPB) in a prospective, randomized, double-blind study of 150 adult patients undergoing primary coronary artery bypass grafting surgery. Patients received either TA (2 g) or large-dose aprotinin (7 million KIU). Thirty additional untreated patients otherwise managed in a similar fashion were included from a recently completed study for comparison of outcomes. Demographic, medical, surgical, laboratory, mediastinal chest tube drainage (MCTD), transfusion, and outcome data were collected. Allogeneic blood product administration was tightly controlled. The demographic, medical, and surgical characteristics did not significantly differ between the two therapy groups. The median postoperative MCTD loss in the TA group did not significantly differ from that in the aprotinin-treated group (708 vs 600 mL). The percentage of patients that received no allogeneic blood products was 25% for the TA group and 27% for the aprotinin group (P = not significant). The median number of allogeneic blood products administered to the TA group (0 U) did not significantly differ from that administered to the aprotinin group (0 U). The percentage of patients with excessive MCTD (>1000 mL/24 h) did not significantly differ between groups (19% and 17%, respectively). In comparison, the control group had a significantly greater (P < 0.05) median MCTD (1020 mL), median allogeneic blood product exposure (4.5 U), and incidence of excessive MCTD (66%) and transfusion therapy (66%). These data help to support the use of pharmacologic methods to improve clinically relevant indicators of blood conservation for primary CPB procedures. Furthermore, the data show that TA is equivalent to aprotinin for blood conservation in patients at risk of excessive post-CPB bleeding and transfusion therapy. ⋯ In a randomized, blind trial, we evaluated the effects of tranexamic acid or aprotinin on blood conservation after primary cardiopulmonary bypass surgery. Both drugs were equally effective in reducing blood loss, the incidence of transfusion, and the amount of blood products transfused compared with placebon.