Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2000
Randomized Controlled Trial Comparative Study Clinical TrialAmbulatory labor epidural analgesia: bupivacaine versus ropivacaine.
Dilute concentrations of bupivacaine combined with fentanyl have recently been used to initiate labor epidural analgesia in an attempt to balance adequate analgesia and minimal maternal motor blockade. Similar concentrations of ropivacaine have not been evaluated. This prospective, randomized, double-blinded study was designed to compare the efficacy of 20 mL of either 0.08% bupivacaine plus 2 microg/mL fentanyl or 0.08% ropivacaine plus 2 microg/mL fentanyl to initiate ambulatory labor epidural analgesia. Forty nulliparous women in early (=5 cm) established labor received either 20 mL of 0.08% bupivacaine plus 2 microg/mL fentanyl (BF) or 0.08% ropivacaine plus 2 microg/mL fentanyl (RF) to initiate epidural analgesia. One woman (BF) required supplemental analgesia, and two (one BF and one RF) had visual analog scale scores > 0 but < 20 at 20 min. The time (mean +/- SD) to visual analog scale score = 0 was BF (n = 18): 12.0 +/- 4.5 min and RF (n = 19): 12.4 +/- 4.0 min (P > 0.05). Spontaneous micturition was observed in 65% (13 of 20) BF compared with 100% (20 of 20) RF (P < 0.01), and ambulation was demonstrated in 75% (15 of 20) BF compared with 100% (20 of 20) RF (P < 0.03). The incidence of forceps delivery was 35% (7 of 20) BF compared with 10% (2 of 20) RF (P < 0.04). The results of this study indicate that dilute ropivacaine combined with fentanyl effectively initiates epidural analgesia while concurrently preserving maternal ability to void and ambulate. ⋯ As compared with a similar dilute concentration of bupivacaine, 20 mL of dilute (0.08%) ropivacaine combined with fentanyl (2 microg/mL) effectively initiates epidural analgesia in nulliparous women in early, established labor while preserving their ability to micturate and ambulate. Of importance, it appears that a true ambulatory epidural analgesic for women in labor is now possible.
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Anesthesia and analgesia · Jun 2000
Clinical TrialHigh frequency jet ventilation in interventional fiberoptic bronchoscopy.
High frequency jet ventilation (HFJV) is a well accepted method for securing ventilation in rigid and interventional bronchoscopy. We describe a technique of HFJV using a 14F nylon insufflation catheter placed in the trachea to support stent implantation or endobronchial balloon dilation in endobronchial stenoses with the flexible fiberscope. One hundred sixty-one cases were treated with either a metal wire stent (n = 105) or with balloon dilation (n = 56). In addition to HFJV, IV anesthesia was applied in 132 cases. Driving pressure was 1125-1275 mm Hg, frequency 80-100/min, and inspiratory:expiratory ratio of 1:2. Fraction of inspired oxygen ranged from 0.3-1.0. The effects on alveolar ventilation were assessed by using blood-gas analysis and continuous monitoring of transcutaneous oxygen and carbon dioxide tension (P(tc)CO(2)). Complications consisted of hypertension (n = 8), hypotension (n = 6), bronchospasm (n = 5), and hypoxia (n = 6). In 52% of the cases, mild hypercarbia (P(tc)CO2 50-60mm Hg) was observed. In two cases, a P(tc)CO(2) > 80 mm Hg resolved spontaneously when the patients returned to normal breathing after intermittent superimposed ventilation with a face mask. During placement of stents in the proximal trachea, the jet catheter had to be withdrawn, resulting in displacement of the catheter into the pharynx in one case, which was managed safely with the bronchoscope. In conclusion, HFJV achieves satisfactory operating conditions and provides adequate gas exchange for interventional bronchoscopic procedures with the fiberscope. ⋯ Safe ventilation is desired when performing tracheobronchial stent implantation and balloon dilation with the fiberscope. High frequency jet ventilation, applied with a 14F insufflation catheter through the nasotracheal route, offers safe ventilatory support with minimal complications. This was evaluated in 161 procedures treating benign and malignant airway stenoses.
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Anesthesia and analgesia · Jun 2000
Toast and tea before elective surgery? A national survey on current practice.
A more tolerant approach to preoperative fasting guidelines for healthy adults undergoing elective surgery was recently recommended by a task force appointed by the American Society of Anesthesiologists. This recommendation liberalizes the intake of clear liquids and specifically allows a light breakfast (e.g., toast and tea or coffee) up to 6 h before elective surgery. We conducted a national survey to determine whether anesthesiologists giving anesthesia in an outpatient setting in the United States were currently following these recommendations, and whether institutional policy reflects these new guidelines. The population consisted of the entire active membership of the Society for Ambulatory Anesthesia, providing an initial sample size of 623 subjects. Most conservatively calculated, we had a response rate of 59.6%. A total of 62% of the respondents said they have an institutional policy in place to allow clear liquids orally 2-3 h before the induction of anesthesia. However, only 35% of the respondents said their institutions had a policy in place allowing a light breakfast 6 h before elective surgery. Nevertheless, only 3% of the responders said they would cancel the operation if a patient actually arrived at the facility after consuming a light breakfast, such as toast and tea 6 h before elective surgery, 32% would delay surgery to later that day, and 65% would proceed without delay. We concluded that most anesthesiologists practicing outpatient anesthesia in the United States have already changed their practice pattern to conform to the recent recommendations of the American Society of Anesthesiologists task force on preoperative fasting time. ⋯ Findings of this national survey conducted among active members of the Society for Ambulatory Anesthesia may encourage anesthesiologists throughout the world to take a more liberal attitude toward allowing clear liquids 2-3 h and a light breakfast 6 h before an elective surgery in healthy patients.
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Anesthesia and analgesia · Jun 2000
Case Reports Randomized Controlled Trial Clinical TrialDoes ketamine have preemptive effects in women undergoing abdominal hysterectomy procedures?
Ketamine may produce "preemptive" analgesia when administered before surgically induced trauma. Therefore, we hypothesized that pre- versus postincisional administration of ketamine would improve pain control after abdominal hysterectomy procedures. Eighty-nine patients were randomly assigned to one of three treatment groups according to a placebo-controlled, double-blinded protocol: Group 1 (placebo) received saline 0.04 mL/kg IV immediately before and after surgery; Group 2 (preincision), received ketamine 0.4 mg/kg IV before skin incision and saline at the end of the operation; and Group 3 (postincision), received saline before skin incision, and ketamine 0.4 mg/kg IV was given after skin closure. The general anesthetic technique was standardized in all three treatment groups. During the first postoperative hour, Group 3 experienced significantly less pain than Groups 1 and 2, as assessed by using both visual analog and verbal rating scales. There were no significant differences between Groups 1 and 2 with respect to pain scores, postoperative opioid analgesic requirements, and incidence of postoperative nausea and vomiting. We conclude that a single dose of ketamine 0.4 mg/kg IV fails to produce preemptive analgesic effects. ⋯ Even though ketamine 0.4 mg/kg IV has short-lasting acute analgesic effects, it failed to produce a preemptive effect when given before abdominal hysterectomy procedures.