Cardiovascular surgical patients' respiratory responses to narcotic analgesia prior to extubation.

摘要

Analgesia is commonly withheld from cardiovascular surgical patients soon to be withdrawn from mechanical ventilation to prevent respiratory depression that can postpone extubation. The effects of analgesia on respiration have been inadequately studied. In this study, weaning parameter measurements were obtained to determine the respiratory impact of a low dose of intravenous morphine in cardiovascular surgical patients ready to be weaned from the ventilator. A pretest-posttest, quasi-experimental, repeated measures design was used. The conceptual model consisted of the physiology of respiration and intrinsic and extrinsic factors affecting respiration. Eleven alert subjects who met two of five weaning parameter criteria received 1 to 5 mg of morphine. Weaning parameters were measured before the intervention and 15 and 30 minutes afterward. Using an alpha level of 0.05, dependent paired t tests were calculated to detect changes due to the morphine. As hypothesized, low dose morphine administration was not found to negatively influence weaning parameters.