Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2002
Meta AnalysisA quantitative, systematic review of randomized controlled trials of ephedrine versus phenylephrine for the management of hypotension during spinal anesthesia for cesarean delivery.
This quantitative systematic review compared the efficacy and safety of ephedrine with phenylephrine for the prevention and treatment of hypotension during spinal anesthesia for cesarean delivery. Seven randomized controlled trials (n = 292) were identified after a systematic search of electronic databases (MEDLINE, EMBASE, The Cochrane Controlled Trials Registry), published articles, and contact with authors. Outcomes assessed were maternal hypotension, hypertension and bradycardia, and neonatal umbilical cord blood pH values and Apgar scores. For the management (prevention and treatment) of maternal hypotension, there was no difference between phenylephrine and ephedrine (relative risk [RR] of 1.00; 95% confidence interval [CI], 0.96-1.06). Maternal bradycardia was more likely to occur with phenylephrine than with ephedrine (RR of 4.79; 95% CI, 1.47-15.60). Women given phenylephrine had neonates with higher umbilical arterial pH values than those given ephedrine (weighted mean difference of 0.03; 95% CI, 0.02-0.04). There was no difference between the two vasopressors in the incidence of true fetal acidosis (umbilical arterial pH value of <7.2; RR of 0.78; 95% CI, 0.16-3.92) or Apgar score of <7 at 1 and 5 min. This systematic review does not support the traditional idea that ephedrine is the preferred choice for the management of maternal hypotension during spinal anesthesia for elective cesarean delivery in healthy, nonlaboring women. ⋯ Phenylephrine and ephedrine to manage hypotension during spinal anesthesia for elective cesarean delivery were compared in this systematic review. Women given ephedrine had neonates with lower umbilical cord blood pH values compared with those given phenylephrine. However, no differences in the incidence of fetal acidosis (pH value of <7.2) or neonatal Apgar scores were found.
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialIntubating laryngeal mask airway size selection: a randomized triple crossover study in paralyzed, anesthetized male and female adult patients.
We determined the optimal size of intubating laryngeal mask airway (ILM) for ventilation and blind tracheal intubation in men and women. We also determined the distance the tracheal tube needs to protrude beyond the distal aperture to ensure that the cuff is through the vocal cords. Fifty male and 50 female anesthetized, paralyzed patients (ASA physical status I or II, aged 18-80 yr) were studied. Three operators (A, B, and C) were involved for the purposes of blinding. The size 3, 4, or 5 ILM was inserted into each patient in random order by Operator A, and the quality of ventilation was scored (adequate, suboptimal, or failed) by Operator B. The fiberoptic position (correct, too shallow, or too deep) and the distance between the distal aperture and the vocal cords was determined by Operator B. A single attempt at blind intubation was made by Operator C. Operators B and C were blinded to the size of the ILM. Operator C was also blinded to the information recorded by Operator B. All ILMs were inserted into the laryngopharynx at the first attempt. For men and women, the ventilation score was smaller for the Size 3 than the Size 4 or 5 (all: P < 0.002). For men, correct positioning was less common with the Size 3 than the Size 4 or 5 (both: P < 0.02). For women, correct positioning was similar among sizes. For men, tracheal intubation was successful less frequently with the Size 3 (84%) than the Size 4 (100%) or 5 (98%) (both: P < or = 0.01). For women, tracheal intubation success was similar among sizes (Size 3, 4, and 5: 86%, 96%, and 92%, respectively). Intubation was always successful if the ILM was correctly positioned and always failed if it was too shallow or deep. In both male and female patients, the distance between the distal aperture and the vocal cords increased with increasing ILM size (all: P < 0.04) and patient height (P < 0.0001) and was always longer for men (all: P < 0.0001). The overall mean distance (95% confidence interval) that the tracheal tube needed to protrude was 10-12 cm (8-13 cm) in men and 8-11 cm (8-12 cm) in women. We conclude that for men, the Size 4 and 5 ILMs are better than the Size 3 for ventilation and blind intubation. For women, the Size 4 and 5 ILMs are better than the Size 3 for ventilation, but there is no difference among sizes for blind intubation. The length the tracheal tube must protrude from the distal aperture to ensure that the cuff is completely through the vocal cords is 8-13 cm, depending on ILM size, the tracheal tube size, and the sex and height of the patient. ⋯ For men, the Size 4 and 5 intubating laryngeal mask airways are better than the Size 3 for ventilation and blind tracheal intubation. For women, the Size 4 and 5 are better than the Size 3 for ventilation, but there is no difference among sizes for blind intubation. The length the tracheal tube must protrude from the distal aperture of the intubating laryngeal mask airway to ensure that the cuff is completely through the vocal cords is 8-13 cm, depending on the size of the mask and tracheal tube and on the sex and height of the patient.
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Anesthesia and analgesia · Apr 2002
Comment Letter Randomized Controlled Trial Comparative Study Clinical TrialReduction of pain on injection of propofol: a comparison of fentanyl with remifentanil.
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialThe effects of intravenous almitrine on oxygenation and hemodynamics during one-lung ventilation.
One-lung ventilation (OLV) induces an increase in pulmonary shunt sometimes associated with a decrease in PaO2 despite ventilation with 100% oxygen. PaO2 improvement has been reported in one-lung ventilated animals receiving IV almitrine, a pulmonary vasoconstrictor. We evaluated the ability of almitrine to prevent a decrease in PaO2 during OLV. Patients without pulmonary hypertension undergoing OLV for lung surgery were randomly assigned to receive either placebo (Group P, n = 8) or almitrine infusion at a rate of 8 microg x kg(-1) x min(-1) (Group A, n = 8) from the start of OLV. Gasometric and hemodynamic values were recorded with the patient in the lateral decubitus position during two-lung ventilation and at 10-min intervals during OLV over a 30-min period (OLV-10, OLV-20, OLV-30). Compared with the values found during two-lung ventilation (434 +/- 22 mm Hg in Group P and 426 +/- 23 mm Hg in Group A), PaO2 decreased at OLV-10 (305 +/- 46 mm Hg), OLV-20 (203 +/- 20 mm Hg), and OLV-30 (178 +/- 18 mm Hg) in Group P (P < 0.05) and at OLV-20 (354 +/- 25 mm Hg) and OLV-30 (325 +/- 17 mm Hg) in Group A (P < 0.05). PaO2 values differed between the groups at OLV-20 and OLV-30 (P < 0.05). Pulmonary artery pressure and cardiac output did not change. In conclusion, 8 microg x kg(-1) x min(-1) IV almitrine prevents and limits the OLV-induced decrease in PaO2 without causing any hemodynamic modification. ⋯ Eight microg x kg(-1) x min(-1) IV almitrine limits one-lung ventilation-induced decrease in PaO2 without causing any hemodynamic modification in patients without pulmonary hypertension.