Abdominal Edema and Inflammation in a Ventilator-Induced Lung Injury Model: Comparison Between Spontaneous Breathing and Mechanical Ventilation
2016 (English)In: American Journal of Respiratory and Critical Care Medicine, ISSN 1073-449X, E-ISSN 1535-4970, Vol. 193, A5224Article in journal, Meeting abstract (Other academic) Published
RATIONALE. The amount of abdominal edema and inflammation were investigated in a porcine model of ventilator-induced lung injury,VILI, and potential differences between spontaneously breathing and mechanically ventilated animals were studied.METHODS. Twelve piglets were submitted to a double hit lung injury. Five lung lavages with warm saline were followed by one hour ofinjurious ventilation: peak airway pressure 32 cmH2O, PEEP 0 and oxygen fraction (FIO2) 1. The animals were randomized into two groups:1. Mechanical ventilation (MV) group (tidal volume: 6 ml/kg, PEEP 15, respiratory rate around 40 and FIO2 0,5); 2. Spontaneous breathing(SB) group (CPAP mode with PEEP 15 and FIO2 0,5). Remifentanil infusion was provided in the SB group, to maintain analgesia while stillenabling spontaneous breathing.After six hours, the piglets were sacrificed and samples from intestine, liver and spleen were collected for histopathological analysis ofinflammation and measurement of wet-dry weight ratio to quantitate the degree of edema.RESULTS. No difference in hemodynamic parameters was observed between the groups.Tidal volume was slightly higher in the SB group (7,3 vs 6 ml/kg in the MV group). Respiratory rate was similar in both groups.Arterial oxygen pressure-fraction (P/F) ratio was higher in spontaneously breathing animals 5 hours after creation of VILI (Group 1: 455 ±27; Group 2: 506 ± 34; p < 0,05). The spontaneous breathing group returned to baseline values of P/F on an average of 3,3 hours (only oneanimal did not reach the baseline value). In the mechanical ventilation group only two animals reached the baseline value during theobservation period of 5 hours.Acute inflammation was present in all three studied abdominal organs and tended to be higher in intestine (Fig. 1) in the MV than SBgroup, but with no difference in liver or spleen. The wet-dry weight ratio showed no difference between the groups.CONCLUSION. The difference in P/F ratio may suggest that the animals on SB with high CPAP recovered faster than the MV group from thelung injury.The tendency to less intestinal inflammation in the SB than MV group may suggest reduced spread of inflammation from the lung and/orbetter intestinal immune response during SB.
Place, publisher, year, edition, pages
2016. Vol. 193, A5224
Respiratory Medicine and Allergy
IdentifiersURN: urn:nbn:se:uu:diva-307948ISI: 000390749604738OAI: oai:DiVA.org:uu-307948DiVA: diva2:1049000
International Conference of the American-Thoracic-Society (ATS), San Francisco, CA, MAY 13-18, 2016