Fluid distribution and pulmonary dysfunction following burn shock.

Respiratory function and body fluid changes were measured in 46 burned patients for up to 7 days postburn (DPB). The patients in this prospective study were divided into an HLS group [n = 17, burn size 61 +/- 0.5% BSA (mean +/- SEM), resuscitated with hypertonic lactated saline] and an iso-Na group (n = 29, burn size 60 +/- 4.5% BSA, resuscitated with lactated Ringer's solution). During DPB 3 to 5, the Respiratory Index (A-aDO2/PaO2), functional extracellular fluid volume (f-ECFV), an ratio of plasma volume to interstitial fluid volume (PV/ISFV) were increased in the iso-Na group compared with the HLS group. During the same period, the Respiratory Index and PV/ISFV correlated significantly; respiratory dysfunction was less in the HLS group. Nearly 50% of the iso-Na group required endotracheal intubation. Sodium loads were the same in both groups; the HLS group required less water. These results suggest that extracellular fluid distribution differs between the two treatments; HLS may be associated with ameliorated respiratory function not only because of less volume loading during resuscitation, but also because the PV/ISFV ratio is less than when lactated Ringer's is administered.