A profile of intravenous nitroglycerin use in cardiopulmonary bypass surgery.

We studied the indications for use, time to onset of effect, approximate effective concentration and therapeutic success of commercially prepared intravenous nitroglycerin (NTG) in 50 patients undergoing cardiopulmonary bypass (CPB) surgery. Nitroglycerin was used to treat systemic or pulmonary hypertension, myocardial ischaemia and ventricular failure. Twenty-one patients had more than one indication for NTG use. Nineteen of 22 patients with pulmonary hypertension, 12 of 13 patients with ischaemic changes, and 13 of 15 patients with ventricular failure improved during intravenous NTG administration. Hypertension during CPB was ameliorated in only six of ten instances. The time to onset of effect ranged from 4.1 +/- 0.8 to 7.8 +/- 2.8 minutes and the mean approximate effective NTG concentration varied from 1.7 +/- 0.3 to 2.9 +/- 0.7 micrograms . kg-1.min-1 (doses only approximate due to our use of an infusion system which absorbs NTG). Complications from intravenous NTG administration were not seen. We conclude that this NTG preparation facilitates treatment of prebypass hypertension, pulmonary hypertension, myocardial ischaemia and ventricular failure but is less effective for the treatment of hypertension during CPB.

Swan-Ganz catheter contamination: a protective sleeve for repositioning.

Valuable haemodynamic data can be derived from a properly positioned Swan-Ganz catheter. Unfortunately, a significant number of these catheters will, for one reason or another, become malpositioned. Withdrawing a catheter from a permanently wedged position presents little difficulty. Repositioning may, however, necessitate its advancement, with the attendant risk of bacterial contamination. We have solved this problem by making a protective sleeve from readily available latex drain and tubing, which fits securely over the haemostatic valve of a No. 8F Cordis introducer. Iodine solution is injected into the sleeve to provide a sterile environment for the Swan-Ganz catheter, which can then be repositioned as required without the risk of bacterial contamination, as verified by bacteriological studies.