The use of intravenous cannulae and the occurrence of thrombophlebitis.

The occurrence of thrombophlebitis in a coronary care unit was studied in relation to the use of short plastic intravenous cannulae. The incidence of thrombophlebitis was 51% in cases where cannulae were used for continuous infusion of glucose 5% and 13% for cannulae which were locked after the injection of heparin. Only one case of infectious thrombophlebitis was seen. The other cases of thrombophlebitis had a chemical or mechanical aetiology. Replacement of glucose 5% by a NaCl 0.9% solution for continuous infusion reduced the incidence of thrombophlebitis to 33%. Heparin-locked cannulae, to provide rapid access to the patient's circulation, proved to be a safe alternative to continuous infusion.