Peripheral vasoconstriction after open-heart surgery.

, , 338-342. Great toe temperatures have been recorded serially after open-heart surgery on 148 patients in order to study the change from a peripherally vasoconstricted to a peripherally vasodilated state. The results in 81 `normals' show a remarkably consistent warm-up pattern which is independent of the duration or nature of operation and of many other potential variables. The reproducibility of this event has enabled us to construct a nomogram which predicts the limits of time within which a patient should warm up if he is recovering normally from operation. In our unit patients should reach a toe temperature of 34°C within 6·5 hours of return to the intensive care unit if they are breathing spontaneously and within 8 hours if they are on intermittent positive-pressure ventilation, time limits at lower temperatures also being defined by the nomogram. It is anticipated that the recognition of the normal postoperative warm-up pattern will facilitate the early detection and effective treatment of circulatory insufficiency after open-heart surgery.