Effects of ATP-MgCl2 administration in hypovolemic dogs

Background. The aim of the study was to evaluate the efficacy of ATP-MgCl2 on myocardial insufficiency associated with hypovolemic shock in dogs. We d esigned the study as a controlled randomized study. Methods. Six mixed-breed dogs weighing 22+/-3 kg were included in the contr ol group and 20+/-3 kg in the ATP-MgCl2 group. After the animals were anest hetized 40 ml/kg of blood was withdrawn in 15 minutes. Animals were observe d for 45 minutes after removal of blood. Six animals received 45 ml/kg of l actated Ringer's solution and the other animals were treated with 45 ml/kg of lactated Ringer's solution and ATP-MgCl2. All measurements were made bef ore removal of blood, 45 min after exsanguination and at 1 hour intervals f or 3 Flours. The following parameters were measured; systemic and pulmonary arterial pressures, pulmonary capillary wedge pressure, central venous pre ssure, cardiac output, rectal temperature, arterial pH, PCO2 and PO2 and mi xed venous hemoglobin oxygen saturation. Tn addition blood samples were col lected for the analysis of lactate and tumor necrosis factor (TNF) concentr ations. Results. After hemorrhage, cardiac index (CI) decreased significantly from 122+/-9 to 52+/-9 ml/kg/min in the control group (p<0.0001) and from 124+/- 11 ml/kg/min to 50+/-6 ml/kg/min in the ATP-MgCl2 group, respectively (p<0. 0001). After volume replacement, Cl was 93+/-6 ml/kg/min in the control gro up and 111+/-4 ml/kg/min in the ATP-MgCl2 group 3 hours after the onset of reinfusion, respectively (p<0.05). TNF was 36+/-5 pg/ml in the control grou p and 21+/-3 pg/ml in the ATP-MgCl2 group (p<0.05). Three hours after the o nset of hemorrhagic shock, a oxygen consumption and delivery were 126+/-14 and 206+/-19 ml/min in the control group and 198+/-16 and 305+/-27 ml/min i n the ATP-MgCl2 group, respectively. At the same time point the oxygen extr action ratio was 0.49+/-0.04 in the control group and 0.61+/-0.03 in the AT P-MgCl2 group (p<0.01). Conclusions. Hemorrhagic shock causes TNF release which may cause multiple organ failure. Organ dysfunction still persists even after the appropriate treatment. ATP-MgCl2 attenuates the release of TNF which may improve the ad verse effects of hemorrhagic shock.