An examination of the physiologic basis for "coronary precautions".

The only restriction in the list of coronary precautions that is well supported by research is the restriction of stimulant beverages. The restriction of taking rectal temperatures and the rationale usually given, vagal stimulation, are not supported by clinical studies. The restriction of iced beverages has some support only if the amount of fluid is about 600 to 800 cc and if the patients is in the supine position, allowing the heart to be cooled. Limiting the ingestion of ice water to a glass of less at a time would seem to be supported by the studies reviewed and by a recent study of healthy young adults. In contrast to the conclusions drawn in this study, a recent national survey of nurses who care for cardiac patients revealed that coronary precautions remain in practice. Mean importance and frequency ratings for the individual restrictions were comparable to ratings for other commonly practiced nursing activities; however, the standard deviations for the mean ratings were greater for coronary precaution items than for others. Hopefully this article will summarize needed information, and nurses will be able to make decisions for practice on the basis of research rather than tradition.