Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1997
Comparative StudyComparison of end-tidal and arterial carbon dioxide in infants using laryngeal mask airway and endotracheal tube.
The laryngeal mask airway (LMA) has become a popular tool for airway management in selected adult and pediatric patients undergoing routine surgical procedures. The relationship between end-tidal and arterial carbon dioxide during controlled ventilation via the LMA in infants under 10 kg has not been reported. After induction of general anesthesia, the LMA was placed in 12 healthy infants and mechanical ventilation initiated. ⋯ The mean end-tidal carbon dioxide and arterial partial pressure of carbon dioxide obtained during ventilation were 42.2 +/- 7.9 and 47.1 +/- 11.0 (LMA) and 37.4 +/- 4.6 and 42.6 +/- 6.7 (endotracheal tube), respectively. Analysis of differences between partial pressure of carbon dioxide and end-tidal carbon dioxide using the Bland and Altman method revealed bias+/-precision of 4.9 +/- 3.9 and 5.3 +/- 3.2 with ventilation via the laryngeal mask and endotracheal tube. Our data indicate that, while ventilating infants under 10 kg with LMA, end-tidal carbon dioxide is an accurate indicator of arterial partial pressure of carbon dioxide.
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Anesthesia and analgesia · Jan 1997
Antinociceptive effect of bupivacaine encapsulated in poly(D,L)-lactide-co-glycolide microspheres in the acute inflammatory pain model of carrageenin-injected rats.
Encapsulating bupivacaine in poly(D,L)-lactide-coglycolide microspheres may prolong analgesia and diminish systemic toxicity. The antinociceptive effect of bupivacaine-loaded microspheres (1, 2.5, and 5 mg) and plain bupivacaine solutions (1, 2.5, and 5 mg) were compared using the vocalization threshold to paw pressure test (VTPP) in rats. Local anesthetic solutions were injected subcutaneously in the plantar hindpaw. ⋯ Duration of antinociception was 60 min with plain bupivacaine (1 mg) and increased to 90, 120, and 180 min, respectively, for the different doses of bupivacaine-loaded microspheres (1, 2.5, and 5 mg). Larger doses of plain bupivacaine (2.5 and 5 mg) induced systemic toxicity. The encapsulation of bupivacaine in microspheres induced a dose-dependent increase in duration of antinociception as compared with plain bupivacaine.