ABSTRACT
Objective: To evaluate cardiac dysfunction of sheep models with decompression sickness with M-mode echocardiography for grading diagnosis combining with auxiliary indexes. Methods: Sixteen sheep were randomly divided into group A, B and C simulating mild, moderate and severe decompression sickness and group D (controls, each n=4). DWC150 animal experimental chamber was used to intervene with decompression scheme. Sheep in group A, B and C were compressed to 200 kPa with compressed air in uniform speed and then treated with light, medium and heavy level of atmospheric pressure simulating the environmental changes of decompression sickness in the speed of 200 kPa/min. The cardiac function was evaluated with echocardiography combined with auxiliary evaluation indexes. Results: The incidence rate of decompression sickness was 83.33% (10/12), and the mortality rate was 33.33% (4/12) in experimental group. After 2 h, 6 h and 24 h's decompression, Tarlov score reduced (F=4.25, 4.98, 5.67, all P<0.05).The white blood cell count and platelet count decreased (t=4.49, 30.92, both P<0.05), prothrombin time prolonged (t=-0.56, P<0.05), fibrin degradation products and D-dimer content increased (t=-20.31, -8.15, both P<0.05) 6 h after high pressure exposure. After decompression, the ejection fraction in experimental group decreased (F=4.00, P<0.05), while the diastolic ventricular diameter ratio (right/left) increased (F=81.31, P<0.05). Conclusion: M-mode echocardiography can be used to grade decompression sickness of sheep models combining with quantitative score and auxiliary evaluation indexes.