[Effects of amniotic fluid embolism-like plasma on isolated perfused rabbit lungs]

In order to investigate whether amniotic fluid could induce the release of mediators from blood cells which would damage the lungs, an isolated perfused rabbit lung (IPRL) was exposed to amniotic fluid embolism-like plasma (AFEP) and the injury of AFEP to lungs and the protective effects of ibuprofen were studied.

10 ml human amniotic fluid and 50 ml heparized rabbit blood were incubated together with or without ibuprofen (600 micrograms) at 37 degrees C for 30 min and centrifuged. Supernatants were taken and were referred to as AFEP or ibuprofen AFEP. IPRL was perfused with AFEP, ibuprofen AFEP, simple amniotic fluid (SAF), supernatant of amniotic fluid (SnAF), rabbit plasma (RP) and control NS. The changes of pulmonary artery pressure (PAP), respiratory pressure (RP) and lung weight were recorded by computer and compared with control NS group.

In groups of SAF, SnAF and RP PAPs were slightly elevated (0.13-0.6 kPa, P > 0.05), and lung weights were not changed. AFEP induced the increase of PAP (3.52 +/- 0.64 kPa, P < 0.05) and lung weight (4.0 +/- 1.0 g, P < 0.01) with the development of lung edema. Administration of ibuprofen prevented partially the APEP-induced increase of PAP (1.87 +/- 0.43 kPa, P < 0.05) and lung weight (0.4 +/- 0.3 g, P < 0.01).

Amniotic fluid may induce the release of mediators from blood cells, and the latter is the important cause resulting in the pathological changes of lungs in amniotic fluid embolism. Ibuprofen may reduce partially the APEP-induced lung injury.