Objective: To investigate the instigating effect of "shock heart" on injury to liver, kidney and intestine at early stage of severe burn in rat.
Methods: Fifty-six healthy male Wistar rats were enrolled in the study and randomly divided into normal control (n=8, without treatment, NC) and burn (n=48, inflicted with 30% TBSA full-thickness scald, B) groups. The rats in B group were intraperitoneally injected with Ringer's lactate solution (4 ml x kg(-1) x 1% TBSA(-1) 30 minutes after burn following the Parkland formula, and they were observed at 0.5, 1.0, 3.0, 6.0, 12.0, 24.0 post-burn hour (PBH), with 8 rats at each time point. The parameters concerning myocardial mechanics, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure( LVEDP), +/-dp/dt max were recorded. The volume of blood flow in liver, kidney and intestine were detected. The serum contents of cTnI, TBA, 32-MG, DAO were determined.
Results: In B group, LVSP and +/- dp/dt max decreased at 1.0 PBH, SBP, DBP and MAP decreased at 3.0 PBH ,all parameters of myocardial mechanics, decreased at 6.0 PBH and still lower than those in NC group at 24.0 PBH (P < 0.01). The volume of blood flow in liver, kidney and intestine in B group were markedly decreased at 1.0 PBH, and gradually decreased during 1.0-12.0 PBH, which were still lower than those in NC group at 24.0 PBH (P < 0.05 or P < 0.01). Compared with that in NC group (1.71 +/- 0.07 microg/L), the serum content of cTnI in B group were increased at 0.5 PBH (2.22 +/- 0.08 microg/ L, P < 0.01), and peaked at 12.0 PBH (7.07 +/- 0.44 microg/L), and persisted at high level (4.57 +/- 0.30 microg/L) at 24.0 PBH. The serum contents of TBA at 3.0 PBH, beta2-MG at 1.0 PBH, DAO at 1.0 PBH was obviously higher than those in NC group (P < 0.05 or P < 0.01), which all showed ascending tendency during 1.0-12.0 PBH.
Conclusion: Myocardial damage is earlier than other organs after severe burn, which is significantly correlated with the parameters of other organs damage and their blood flow volume. Shock heart may be one initiate factor to induce the damage of liver, kidney and intestine and decrease of their blood flow volume after severe burn.