OTHER THERAPEUTIC MODALITIES



The development of pharmacological agents to treat or, more importantly, prevent ARDS would represent a major advancement. Early adminis­tration of high-dose corticosteriods over a brief period is of questionable value in gram-negative sepsis and has no proven efficacy in ARDS due to other etiologies. Antiprostaglandin agents, e.g., ibuprofen, affect the course of experimental dis­ease leading to ARDS, but extension to the bed­side is premature.

Antibiotics are the most important group of agents, as correct treatment of infection may be lifesaving while the failure to recognize infection ensures the continuation of the pulmonary cap­illary leak. As far as possible, antibiotics should be selected on the basis of reliable microbial stud­ies, but until the results are known empiric ther­apy is not only appropriate but necessary. Con­tinued sepsis in the face of appropriate antibiotics raises the spectre of an abscess and should lead to an aggressive diagnostic search, as this is a com­mon cause of persistent ARDS and a fatal out­come. The lungs and the peritoneal cavity are the commonest sites of undiagnosed infection.

Appropriate fluid management is important to ensure adequate cardiac output and thus 02 de­livery. Fluid loading to maintain adequate cardiac filling pressures in the face of the high intrathor­acic pressures generated during mechanical ven­tilation must be balanced against the resultant in­crease in microvascular pressure and its tendency to increase the extravascular lung water accu­mulation. The controversy over the use of colloid vs. crystalloid therapy is moot in the presence of such marked alterations in microvascular perme­ability. Until more is known concerning the dy­namics of fluid movement in this disease, a good rule of thumb is to maintain filling pressures in a normal range (pulmonary artery wedge pres­sures of about 10 cm H20).