ABSTRACT
Objective In order to extrapolate the respiratory dysfunction of patients in early stage of acute organophosphorus pesticide poisoning (AOPP),transpulmonary thermodilution technique was used in swine models of severe acute dichlorvos poisoning (SADP) to evaluate respiratory function.Methods Twenty healthy female swine were randomly divided into dichlorvos ( n =7 ),atropine ( n =7 ) and control (n =6) groups.In the dichlorvos group,the swine were administered with 80％ emulsified dichlorvos (100mg/kg) via the gastric tube toinduce SADP.In the atropine group,swinewere administered with dichlorvos,and 0.5h later,atropine was injected to obtain and maintain atropinization.The swine of control group were administered with saline solution instead.Arterial and venous blood samples were collected 0,0.5,1,2,4 and 6 hours after modeling for blood gas analysis and detecting acetylcholinesterase levels.Both extravascular lung water index (EVLWI) and pulmonary vascular permeability index ( PVPI ) were measured by using PiCCO (pulse indicator continuous cardiac output ). At the termination of the experiment,the animals were sacrificed and the lung wet/dry weight ratio was determined and histopathological changes of lung tissue were also observed under microscope.Results In the dichlorvos group,EVLWI and PVPI were substantially increased from 0.5 h to 6 h after modeling but PaO2/FiO2 decreased from 0-6 h after modeling.In the atropine group,EVLWI and PVPI increased initially,but then they decreased 1 h afterwards and PaO2/FiO2 was also gradually decreased from 0-1 h.In both dichlorvos group and atropine group,the EVLWI was negatively correlated with PO2/FiO2 and positively correlated with PVPI.Compared with the control group,the lung wet/dry weight ratio increased markedly in the dichlorvos group and mildly increased in the atropine group.Meanwhile,the histopathological changes of lung tissue were obvious in the dichlorvos group and mild in the atropine group.Conclusions SADP swine experienced substantial changes in respiratory function. EVLWI was a reliable and valuable indicator for evaluating respiratory function in the early stage of AOPP.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate cardiac function and myocardial perfusion during 48 h after cardiopulmonary resuscitation (CPR), further to test myocardial stunning and seek indicators for long-term survival after CPR.</p><p><b>METHODS</b>After 4 min of untreated ventricular fibrillation, fifteen anesthetized pigs were studied at baseline and 2 h, 4 h, 24 h, and 48 h after restoration of spontaneous circulation (ROSC). Hemodynamic data, echocardiography and gated-single photon emission computed tomography myocardial perfusion images were carried out.</p><p><b>RESULTS</b>Mean arterial pressure (MAP), coronary perfusion pressure (CPP) and cardiac troponin I (CTNI) showed significant differences between eventual survival animals and non-survival animals at 4 h after ROSC (109.2 ± 10.7 mmHg vs. 94.8 ± 12.3 mmHg, P=0.048; 100.8 ± 6.9 mmHg vs. 84.4±12.6 mmHg, P=0.011; 1.60 ± 0.13 ug/L vs. 1.75 ± 0.10 ug/L, P=0.046). Mitral valve early-to-late diastolic peak velocity ratio, mitral valve deceleration time recovered 24 h; ejection faction and the summed rest score recovered 48 h after ROSC.</p><p><b>CONCLUSION</b>Cardiac systolic and early active relaxation dysfunctions were reversible within survival animals; cardiac stunning might be potentially adaptive and protective after CPR. The recovery of MAP, CPP, and CTNI could be the indicators for long-term survival after CPR.</p>
Subject(s)
Animals , Male , Blood Pressure , Cardiopulmonary Resuscitation , Coronary Circulation , Heart Arrest , Hemodynamics , Myocardial Contraction , Physiology , Myocardial Stunning , Swine , Time Factors , Ventricular FibrillationABSTRACT
Objective To investigate the effect of hypertensive perfusion which induced by norepinephrine on the TNF-α and IL-6 in serum and the activity of Na~+-K~+-ATPase in lung tissue and to observe the morphology of lung tissue. Method Ten domestic pigs were suffered from ventricular fibrillation for 4 minutes and applied cardiopulmonary resuscitation. The pigs they were divided into two groups. Hypertensive perfusion group( n = 5) :the mean arterial pressure, which induced by norepinephrine was maintained as 130% as baseline for 4 hours; nor-real perfusion group( n = 5) : the mean arterial pressure was maintained as baseline for 4 hours, too. Hemodynamic parameters was observed, blood samples were extracted to detect the TNF-α and IL-6 in serum at the time of baseline, 10 min, 2 h and 4 h after successful resuscitation. The expression of Na~+ -K~+ -ATPase in lung tissue and the change of ultrastmeture and pathology in lung tissue was detected at 24 h. All values were analyzed by student' s t test. Results There was no influence on hemodynamic parameters except the blood pressure and heart rate in hypertensive perfusion group. The release of TNF-α and IL-6 were reduced(P < 0.01 ) and the activity of Na~+-K~+ -ATPase was upgraded in hypertensive perfusion group. Hypertensive perfusion could play a protective role on the morphology of alveolar cell. Conclusions Hypertensive perfusion which induced by norepinephrine could reduce the release of inflammatory cytokines, upgrade the activity of the Na~+-K~+-ATPase, decrease the consumption of surfactant and have an important protective effect on lung tissue.