Intralipid alterations in pulmonary prostaglandin metabolism and gas exchange.

To assess the role of Intralipid as a prostaglandin (PG) precursor, we infused Intralipid into 40 rabbits with long-term arterial and venous catheters; 24 other rabbits received a control saline infusion. One-half of the rabbits in both experimental and control groups had oleic acid-damaged lungs, and at least 5 in each of the 4 groups (Intralipid/saline in normal/damaged lungs) received indomethacin. Two vasodilating PGs (E2 and 6KF1 alpha) and one vasoconstricting PG (F2 alpha) were measured. Triglyceride levels increased significantly in all Intralipid groups, averaging 580 mg/dl. Intralipid-related alterations in PG levels and arterial oxygen tension (PaO2) were significant only in the lung-damaged group. The mean (+/- sem) decrease in PaO2 was 12 +/- 1.5 torr (p less than .001). For both vasodilating PGs, Intralipid infusion increased the pulmonary arteriovenous gradients for PG E2 and PG 6KF1 alpha by 960 pg/ml (p less than .05) and 697 pg/ml (p less than .10), respectively. Both the PaO2 decrease and the vasodilating PG increases were blocked by indomethacin. In summary, Intralipid infusion in lung-damaged rabbits increased pulmonary production of vasodilating PGs and associated hypoxemia, presumably caused by an unblocking of hypoxic vasoconstriction and resultant increase in intrapulmonary right-to-left shunt.

A two and one half year clinical experience with a mechanical left ventricular assist pump in the treatment of profound postoperative heart failure.

A sac-type paracorporeal left ventricular assist pump was implanted in 9 patients suffering from profound left ventricular failure following open heart surgery. Two patients had good recovery of left ventricular function and were weaned from assist. One survived 14 months postoperatively. Primary causes of death among the remaining patients were (1) primary right ventricular failure, (2) assist pump inlet cannula obstruction and (3) excessive bleeding. The strategies developed or proposed to deal with these problems include, respectively: (1) biventricular assist for patients with concomitant right ventricular failure; (2) cannulation of the left atrium to avoid inlet cannula obstruction by the left ventricular wall and intraventricular septum; (3) more rapid selection of left assist candidates and more rapid implantation techniques to reduce the coagulopathy associated with prolonged cardiopulmonary bypass, and an effective autotransfusion system to augment blood replacement.