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Objective To establish an animal model for study on early oral fluid resuscitation of burn shock so as to provide experimental basis for oral fluid resuscitation of burn shock in wars, accidents or disasters. Methods Male Beagle dogs weighing 11-13 kg were used in the study and the carotis, jugular and duodenum were cannulated respectively for measurement of homodynamics, tissue perfusion and gastrointestinal function. Dogs were subjected to a 35% TBSA full thickness flame injury with 10-mi-nute anesthesia by intravenous injection of propofol 24 hours later, and then randomly and equally divided into two groups(8 dogs in each group) : no fluid resuscitation group (NR group) undergoing no treatment in the first 24 hours post burn and oral fluid resuscitation group ( OR group) undergoing gastric infusion of glucose electrolyte solution (GES) according to Parkland formula. From the second 24 hours post burn, animals in two groups were given delayed Ⅳ fluid resuscitation, and then intravenous nutritional support was initiated at the 72nd hour. The mean arterial pressures (MAP), cardiac output (CO), dp/dt max of left ventricular contractility (dp/dtmax) and plasma volume (PV) were monitored continuously. The pa-rameters of gastrointestinal tissue peffusion, the rates of gastric emptying and intestinal absorption of GES were determined, the morbidity was also recorded at the end of 5-day experiment. Results After 35% TBSA burn injury, MAP, CO,dp/dt max and PV dropped markedly and gastrointestinal tissue perfusion reduced obviously. CO and PV in OR group were significantly higher than those in NG group at 4, 8 and 24 hours after burn. Homodynamic parameters and gastrointestinal tissue perfusion in OR group were pro-moted to pre-injury level at 48 and 72 hours respectively, while homodynamic parameters in NR group did not return to pre-injury level till 72 hours, and gastrointestinal tissue perfusion kept lower than pre-injury till 120 hours post burn. Rates of gastric emptying and intestinal absorption of GES significantly reduced to the lowest level (42% and 37% of pre-injury) at about 4 hours post bum, but did not return to pre-in-jury level till eight hours post bum. Over five days, two out of eight dogs (25%) died in NG group but none in OR group. Conclusions The animal model can exactly simulate the actual circumstance, where oral resuscitation is superior to Ⅳ resuscitation in some aspects in treating early bum shock in wars, accidents and disasters, and provide practical and reliable method for measurement of homodynamic parameters, tissue perfusion, gastric emptying and intestinal absorptive function.
RESUMO
Objective To investigate the effect of oral fluid resuscitation on circulatory oxygen dynamic parameters in dogs with burn shock.Method Eighteen male Beagle dogs were surgically prepared for the cannulation of carotid cartery and jugular vein,subjected to flame injury 50%total body surface area(TBSA)with fullthick ness 24 hours later,and they then randomly divided into 3 equal groups.The oral fluid resuscitation group (OR group)was intragastrieally injected with infusion of glucose-electrolyte solution(GES)according to parkland formula 0.5h after burn with a dose of 4mL·kg-1·% TBSA-1.Intravenous (IV) GES resuscitation group (VR group)was intravenously injected with infusion of GES as the same dose as OR group,and no-fluid resuscitation (NR)group did not receive any treatment during the first 24 hotrs.In the second 24 hours,all dogs received Ⅳ fluid resuscitation.At the end of 72 hours of injury.the mortality in each group was recorded.The mean arterial arterial pressure(MAP),hematocrit(HCT)and blood lactic acid(LAC)were determined,and blood gas analysis was evaluated for oxygen delivery(DO2),oxygen consumption(VO2)and oxygen uptake(O2ext)before injury and 2,4,8,24,48 and 72 hours after injury.Results Burn injury resulted in a 77.1%decrease in MAP,and a 48.5% increase in HCT and 533.7%increase in LAC in NR group,followed by pngressively lowering of DO2,VO2 and Oext till all animals died with in 24 hours after burn.MAP and HCT levels oftwo resuscitation groups gradually returned to the pre-injury levels within 72 hours after burn,but the LAC levels sill remained significantly higher than the pte-injury levels(P＜0.01).The MAPs of OR group were higher at corresponding intervals within 24 hours post burn than those of NR group(P＜0.01),but they were lower than those of VR group(P＜0.01).The serum LAC in OR group was markedly lowered than that in NR group,but it was higher than that in VR group.Twenty-four hours after burn injury,the DO2 level in OR group showed no significant differences compared with that of the VR group,but the levels of the VO2 and Oext were still much lower than those of VR group (P＜0.01).At the end of 72 hours,3 dogs of NR group died and none of IV group died.Caadusions Oral fluid resuscitation improves oxygen dynamic,alleviates hyperlactacidemia and reduces the mortality of animals with severe burn shock.
RESUMO
Objective To investigate the effect of carbachol on local gut inflammation during entetal resuscitation of rats with bum shock. Method Thirty-eight Wistar rats were subjected to 35%TBSA full thickness scald injury, and enteral fluid was infused into animal intestines via duodenal stomas 30 minutes post bum. The animals were randomly divided into four groups: no resuscitation (Control, n = 8), enteral resuscitation using either a glucose electrolyte solution (GES, n = 10) or GES plus carbachol (60 μg·kg-1,GES/CAR, n = 10), or carbachol alone (CAR, n = 10) .The volumeof GES infusion was based on the Parkland formula (4 ml· 1% TB-SA-1·Kg-1) - All animals were sacrificed 4 hours post bum, and specimens of jejunal tissue were collected to determine the levels of tumor necrosis factor (TNF)-α, nitric oxide (NO), nitric oxide synthase (NOS) and myeloperoxidase (MPO). Serum assays for plasma diamine oxidase (DAO) activities were also performed. Results There were no statistical differences in the intestinal levels of NOS, NO, TNF-α and MPO, and plasma OAO activities, between the GES group and the control group. Compared to the GES group, the GES/CAR group showed significantly lowered levels of intestinal NOS (1.276 ±0.391 vs. 1.818 ±0.436, P＜0.05), NO (0.925 ±0.402 vs. 1.561 ±0.190, P ＜ 0.05, TNF-α (0.87±0.13 vs. 1.94±0.47, P ＜0.01) and MPO (0.465 ±0.092 vs. 0.832±0.214, P＜0.05),and reduction in plasma DAO activites (0.732±0.192 vs. 1.381 ±0.564, P ＜0.05). The CAR group also showed significantly lowered levels of intestinal NOS, NO, TNF-α and MPO and reduced plasma DAO activites, compared to the GES group. Conclusions Theses results suggest that carbachol significantly inhibits the release of proinflammatory mediator and attenuates local inflammation in gut during enteral fluid resuscitation of rats in rats with bum shock. We postulate that carbachol may exert its and-inflammatory effects via the cholinergic anti-inflammatory pathway.
RESUMO
Objective To study the resuscitative effect of hypertonic electrolyte glucose solution (HEGS) on the haemodynamics pa-rameters in enteral resuscitation of burn shock. Methods Eighteen beagle dogs with 35% TBSA third degree burned were used in this stud-y. They were random divided into no-resuscitation group (NR group), enteral resuscitation with HEGS group (EH group) and intravenous resuscitation with isotonic electrolyte glucose solution (lEGS) group (Ⅱ group). The fluid resuscitation was given from half an hour after TBSA). The haemodynamics parameters (cardiac index, mean arterial pressure, intrathoracic blood volume index, and systemic vascular re-sistance index) were continuously assessed by PICCO. Result The cardiac output index reduced markedly after bum in the three groups, and then returned after 2h in two resuscitation groups, which were higher than that in the NR group( P<0.05). The mean arterial pressure reduced in the three groups, which was higher in the two resuscitation groups than that in NR group(P < 0.05). The intrathoracic blood volume index was rapidly reduced in the three groups. It returned in EH group from 2 hours after burned, which was still higher than that in the other two groups (P < 0.05). Meanwhile the systemic vascular resistance index was increased quickly. It was reduced in EH group from 2 hours after burned, which was lower than that in the other two groups (P < 0.05). Conclusion The results show that it was feasible for 35% TBSAⅢ° burn-injury dogs to be resuscitated with 1.8% hypertonic electrolyte-glucose solution by enteral, which can markedly reduce liquid quantity needed.
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Objective To observe the effects of carbachol(a cholinergic agent)on gastric emptying and gastric blood flow in resuscitation of early shock with oral administration of glucose-electrolyte solution(GES)in scalded rats.Methods Seventy-eight male Wistar rats were randomly assigned into five groups:shame scald(n=6),scald without fluid resuscitation(n=18),scald resuscitated with oral GES alone(n=18),scald resuscitated with oral carbachol alone(CAL,n=18),and scald resuscitated with oral carbachol plus GES(GES/CAL,n=18).About 35% TBSA scalded injury on back of rats was produced with boiling water(100℃,15s)in the latter four groups.GES(2ml/kg,which is equivalent to half volume of fluid infusion in first 24 hour according to Parkland' formula)was given twice in two-hour intervals by gavage beginning from 30min after the injury in GES and GES/CAL group.Carbachol(60?g/kg)was gavaged 30min after the injury in CAL and GES/CAL group.The gastric emptying rate was determined by phenol red emptying method and gastric blood flow was measured with laser Doppler at 2h,4h and 6h after the scald injury.Results The gastric emptying was obviously delayed and gastric blood flow was significantly reduced in scald animals compared with those in sham group(P