Effects of prone and supine position on oxygenation and inflammatory mediator in a hydrochloric acid-induced lung dysfunction in rats.
OBJECTIVE
To compare the effectiveness of mechanical ventilation of supine versus prone position in hydrochloric acid (HCl)-induced lung dysfunction.


METHODS
Twenty, adult, male, Wistar-EPM-1 rats were anesthetized and randomly grouped (n=5 animals per group) as follows: CS-MV (mechanical ventilation in supine position); CP-MV (mechanical ventilation in prone position); bilateral instillation of HCl and mechanical ventilation in supine position (HCl+S); and bilateral instillation of HCl and mechanical ventilation in prone position (HCl+P). All groups were ventilated for 180 minutes. The blood partial pressures of oxygen and carbon dioxide were measured in the time points 0 (zero; 10 minutes before lung injury for stabilization), and at the end of times acid injury, 60, 120 and 180 minutes of mechanical ventilation. At the end of experiment the animals were euthanized, and bronchoalveolar lavages (BALs) were taken to determine the contents of total proteins, inflammatory mediators, and lungs wet-to-dry ratios.


RESULTS
In the HCl+P group the partial pressure of oxygen increased when compared with HCl+S (128.0+/-2.9 mmHg and 111.0+/-6.7 mmHg, respectively) within 60 minutes. TNF-alpha levels in BAL do not differ significantly in the HCl+P group (516.0+/-5.9 pg/mL), and the HCl+S (513.0+/-10.6 pg/mL).


CONCLUSIONS
The use of prone position improved oxygenation, but did not reduce TNF-alpha in BAL upon lung dysfunction induced by HCl.
Oliveira
Wagner Rogério Souza de
WR
Division of Experimental and Technical, UNIFESP, Sao Paulo, Brazil. souza.oliveira@unifesp.br ijuniors@hotmail.com
Silva
Ivaldo da
Id
Simões
Ricardo Santos
RS
Fuchs
Luiz Fernando Portugal
LF
Oliveira-Filho
Ricardo Martins
RM
Oliveira-Júnior
Itamar Souza de
IS
D000818:Animals; D006851:Hydrochloric Acid / Q000494:pharmacology; D008171:Lung Diseases / Q000139:chemically induced / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D010100:Oxygen / Q000097:blood; D016684:Prone Position / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012121:Respiration, Artificial; D016683:Supine Position / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D014409:Tumor Necrosis Factor-alpha; D006851:Hydrochloric Acid; D010100:Oxygen