Curative effect of pleural lavage on open chest trauma caused by seawater immersion

Abstract

Background and objectives: Open chest trauma with seawater immersion can lead systematic inflammatory response and multiple organ dysfunction syndromes (MODS). Early intervention of seawater immersion significantly decreases mortality. This study aims to explore the curative effect of pleural lavage in the treatment of open chest trauma caused by seawater immersion on dogs.

Design and settings: An in vivo experimental study was performed in healthy cross-breeding adult dogs (n=20).

Subjects and methods: A dog model of open chest trauma caused by seawater immersion was established. All experimental dogs were divided into control group and pleural lavage group, with 10 dogs in each group. In the control group, dogs were performed ventilator-assisted breathing, and thoracic tube was kept open for adequate chest water drainage; in the pleural lavage group, dogs were further injected with 0.9% sodium chloride (35 mL/kg) immediately into the right side of the chest after the pleural effusion was drained off. The internal environment, oxygen partial pressure, and pathological changes of the lung tissue were observed and recorded.

Results: Following open chest trauma caused by seawater immersion, both groups showed obviously increased serum sodium and plasma osmolality and sharply decreased oxygen partial pressure. After treatment, the serum sodium and plasma osmolality decreased, whereas oxygen partial pressure increased in both groups. The pleural lavage group showed better improvement than the conventional treatment group. The pathological changes in the pleural group were lighter than in the conventional treatment group.

Conclusion: Compared with conventional treatment, repeated pleural lavage shows improved treatment in the correction of blood hypertonic state and hypoxemia in seawater-immersed open chest trauma.

Figure 1

Serum electrolytes levels and plasma crystal osmotic pressure values before and after the injury in the control group and the pleural lavage group (mmol/L). A) Animals in the pleural lavage group had significant lower serum sodium values than in the control group at 1 h, 2 h, and 4 h. B) There was no significant difference in serum potassium between two groups. C) There were no significant differences in urea nitrogen between two groups at any time points. D) No significant differences were found in blood sugar between two groups. E) Animals in the pleural lavage group had significant lower plasma crystal osmotic pressure values than in the control group at 1 h, 2 h, and 4 h. * indicates significant differences between the control group and the pleural lavage group at the same time points. BI: before injury. P<.05 is considered as statistically significant difference.

Figure 2

Arterial partial pressure of oxygen (pO₂) and partial pressure of carbon dioxide (pCO₂) before and after injuries in the control group and the pleural lavage group (mm Hg). A) Arterial pO2 were significantly lower in the pleural lavage group than in the control group at 1 h, 2 h, 4 h, and 8 h. B) There were no significant differences in arterial pCO₂ between the two groups at any time points. BI: before injury. P<.05 is considered as statistically significant difference.

Figure 3

Morphological changes of pulmonary tissue in animals with open chest trauma caused by seawater immersion (×400 magnification). A) Alveolar wall collapse, visible serous effusion, widened alveolar interval, lymphocyte infiltration, and capillary congestion were found in lung biopsy of the control group. B) Milder alveolar wall collapse, less alveolar exudates, less obvious widened alveolar interval, and no distinct capillary congestion were found in lung biopsy of the pleural lavage group.