Experimental Study on Acute Heart Failure Following Seawater Immersion in Dog with Open Abdominal Injury

Background of previous reports indicate seawater immersion wound injuries: compression symptoms caused seawater into the chest and abdominal cavity, hypertonic dehydration, hypothermia and pathogen infection, resulting in various systems of the human body appears unique pathological different from the general trauma physiological and clinical manifestations. Seawater immersion wound field of study, the research priorities of the foreign soaked in sea water caused by hypothermia, and reported a variety of methods of rewarming. Third Military Medical University, Institute of Field Surgery, Navy General Hospital naval battle injury research center is in the country to carry out extensive seawater immersion wound research earlier and more in-depth institutions, the impact of different organs and tissues of the body, but for immersion wound caused reported heart damage (heart failure) mechanism still is rare. Complex pathogenesis of heart failure, the Frank-Starling mechanism and neurohumoral compensatory mechanisms, depletion of myocardial energy point of view, does not fully explain the progress of heart failure. Heart failure largely occur at the molecular level mechanism, research has shown that cytokines such as tumor necrosis factor-α (tumor necrosis factor-α, TNF-α), etc. are also involved in the pathogenesis of heart failure, heart failure plays an important role in the occurrence and development. This topic is based on the above content designed. On the basis of injuries combined with seawater immersion canine heart failure model in the successful establishment of the abdomen open, observe the open abdominal injury and seawater immersion the canine plasma tumor necrosis factor-alpha (tumor necrosis factor-α, TNF-α), nitric oxide (nitric oxide changes in NO) and brain natriuretic peptide (B-type natriuretic peptide, BNP), aims to explore the mechanism of acute heart failure development may open abdominal injury and seawater immersion (especially the possible future for the clinical treatment of seawater immersion wound acute heart failure after the war in the Taiwan Strait) to provide new experimental evidence and clinical treatment methods. Purpose. Establish open abdominal injury and seawater immersion induced experimental animal model of acute heart failure in dogs. 2. Preliminary inquiry open abdominal injury and seawater immersion result in the pathogenesis of acute heart failure. Methods adult mongrel dogs 16 Preparation of open abdominal injury in animal models, were randomly divided into seawater immersion group and the control group, n = 8. Respectively in injury, after injury, soak 0.5h, 1h, 2h and water immediately, 1h, 2h each time point were monitored dogs mean arterial pressure (MAP), pulmonary capillary wedge pressure (PAWP), central venous pressure ( CVP), cardiac output (CO), plasma K, Na, CL-osmotic pressure, PH value, HCO3-, PaCO2, BNP, TNF-α and NO in content measured before the injury, soak 2h ultrasound echocardiography left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), Bo output (SV), left ventricular ejection fraction (LVEF) values. Results 1. Seawater immersion merger abdomen open hurt dogs hemodynamic changes significantly: immersion group dog during the experiment, mean arterial pressure (MAP), central venous pressure (CVP), cardiac output (CO) were persistent decline, to soak 2h when, PAWP up to the highest value (25mmHg), significantly higher than pre-injury and control group, CO decreased by 60.61% than the pre-injury, reduced by 55.17% compared with the control group, and PAWP for, CO before injury and the control group compared were significantly difference (p lt; 0.01), the immersion group dog MAP, CVP declining. Seawater immersion merger abdomen open injury in dogs ultrasound heart diagram abnormal cardiac function parameters were significantly: the soaked group soaked for 2 h LVESV increased by 72.73% compared with before the injury, SV decreased 30.88%, 39.16% decline in LVEF were significant changes ( P lt; 0.01). Significantly higher (P lt; 0.01) compared with the control group, the same time, LVESV, SV, LVEF was significantly lower (P lt; 0.01): and LVESV increased 42.77%, the SV reduce 25.98%, 29.12% reduction in LVEF. No significant change in the control group before and after the above indicators of injury (P gt; 0.05). The seawater immersion merger abdomen open injury significant water and electrolyte acid-base balance disorders in dogs: the immersion group dog soaked Na ^{K Cl - level and blood osmolality levels increased significantly, no significant change in the control group dogs; the immersion group degree of acidosis gradually increased during the experiment. Blood PH value, HCO3 - were reduced, than the injury before and the same point in time in the control group showed a significant difference (P lt; 0, 05). Has always been no significant change in the PH value of the control group and the HCO ₃ - , acidosis occurs. The two sets of arterial PaCO ₂ injured back and forth between the two groups had no significant difference. Seawater immersion combined open abdominal injury and dog plasma cytokine changes: the immersion group dog plasma BNP levels gradually increased effluent instantly reached the highest value (447.95 pg / ml) after not continue to rise, and there is no obvious decline. No significant change in the control group dog plasma BNP; immersion group dog soak TNF-α levels gradually increased to soak 0.5h with the control group, the same point in time and the injury before the comparative change significantly (P lt; 0, 05), water 1h up to the highest value (5.68 ug / L), no significant change in the control group dogs TNF-α; plasma NO were significantly increased in the the immersion group dog soaked, the water instantly reached the highest value (156.75 umol / L), with the injury before the control group compared to the same point in time there is a significant change (P lt; 0.01), and no significant change in the control group dog plasma NO level. Conclusion 1 open abdominal injury established animal models of acute heart failure after seawater immersion. Seawater into the abdominal cavity can aggravate the progression of open abdominal injury and seawater immersion and open abdominal injury a double blow caused by experimental animals with acute heart failure: relative to pure open abdominal injury and seawater immersion wound the animals reduced effective circulating blood volume , Na , K , Cl - , the level of blood osmolality increased significantly, PH value, HCO ₃ - decreased gradually increased the degree of acidosis. Various cytokines were significantly changes: plasma BNP, TNF-α, NO levels were significantly increased. The combined effects of many factors causing myocardial ischemia and hypoxia, to severe energy metabolism, reduced myocardial contractility, heart function suppression, eventually leading to the failure of the pump function.}