OBJECTIVETo investigate the influence of delayed rapid fluid resuscitation on oxygen metabolism in dogs with burn shock.

METHODSTwenty-four mongrel dogs inflicted with 40% TBSA full thickness scald were enrolled in the study and randomly divided into burn control (C), delayed even fluid replacement (E), and delayed rapid fluid replacement (R) groups, with 8 dogs in each group. The changes in oxygen delivery (DO(2)), oxygen consumption (VO(2)), oxygen extraction (O(2)ext) and blood base deficit (BD), and lactate (LA) were determined before scalding and at 2, 6, 8, 12, 24, 36 and 48 post scalding hours (PSHs).

RESULTSThe DO(2) in each group was decreased obviously after scalding and was evidently lower than that before injury (P < 0.01), while the O(2)ext value markedly increased compared with that before scalding (P < 0.01). After fluid resuscitation, DO(2) and VO(2) in E and R groups increased, but O(2)ext decreased. The values of DO(2), VO(2) and O(2)ext showed significant differences between R and E groups at 8 PSH (R group vs E group, DO(2): 7.35 +/- 0.21 L.min(-1).m(2) vs 5.32 +/- 0.96 L.min(-1).m(2), P < 0.01; VO(2): 2.02 +/- 0.58 L.min(-1).m(2) vs 1.71 +/- 0.38 L.min(-1).m(2), P < 0.01); The blood BD levels in each group were remarkably lower after scald than that before scald (P < 0.01), and they gradually increased after fluid replacement. The blood BD level in R group at 8 PSH (-6.5 +/- 0.7 mmol/L) was obviously higher than that in E group (-9.3 +/- 1.4 mmol/L, P < 0.01). The blood LA level in each group were evidently higher than that before scald (P < 0.01), and they decreased after fluid replacement. The blood LA level in R group at 8 PSH (2.30 +/- 0.20 mmol/L) was obviously lower than that in E group (2.67 +/- 0.30 mmol/L, P < 0.01)

CONCLUSIONRapid fluid replacement could improve tissue oxygen metabolism, which was beneficial to the correction of tissue oxygen supply when fluid resuscitation was delayed.