Oxygenation and lung morphology in a rabbit pediatric ARDS- model under high peak pressure ventilation plus nitric oxide and surfactant compared with veno-venous ECMO.

Abstract

UNLABELLED:

The aim of the study is to investigate which of two treatment options of saline lavage induced ARDS in rabbits is better in terms of oxygenation and prevention of barotrauma: combined high peak pressure ventilation with surfactant administration and inhaled nitric oxide or veno-venous ECMO combined with low peak inspiratory pressure ventilation.

MATERIALS AND METHODS:

After saline lavage (10 cc/kg repeated as long as foamy retrieval was observed) two combined therapeutic strategies were examined: ventilation with high inspiratory pressures (35 cm H2O) with additional exogenous surfactant administration (100 mg/kg) and inhaled nitric oxide (10 PPM) (n=5, group 1) and low inspiratory pressure (20 cm H2O) ventilation under veno-venous ECMO support (n=5, group 2). The FiO2 was maintained at 1.0 in both groups. The paO2/FiO2 ratio was calculated in 30 minute intervals for 4 hours. After that the animals were sacrificed and the lungs examined macro- and microscopically. Aeration was described in a semiquantitative method using the alveolar expansion index. Oxygenation in group 1 was significantly better than in group 2, it increased significantly after surfactant but not after additional nitric oxide administration. However, the lungs in group 1 showed severe signs of baro/ergotrauma (Hyaline membranes, air leaks, infiltration of polymorphonuclear (PMN) granulocytes and macrophages, break down of alveolar capillary membranes) after 4 hrs of combined therapy, whereas the lungs in group 2 appeared normal. Adding surfactant and NO to a high tidal volume ventilation improved oxygenation, but did not prevent baro/ergotrauma. Ventilation with low inspiratory pressures combined with ECMO caused little baro/ergotrauma but adequate oxygenation could not be achieved, probably due to anatomical features of the rabbit which do not allow appropriate blood flow within the ECMO-circuit.

• Authors: J C Möller, I Reiss, T F Schaible, M Kohl, W Göpel, T Fischer, E M Nitsche, S Krüger
• Journal: The International journal of artificial organs (Int J Artif Organs) Vol. 22 Issue 11 Pg. 747-53 (Nov 1999) ISSN: 0391-3988 [Print] United States
• PMID: 10612302 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Pulmonary Surfactants
• Nitric Oxide
• Oxygen

Topics

• Animals
• Barotrauma (prevention & control)
• Disease Models, Animal
• Extracorporeal Membrane Oxygenation (methods)
• Humans
• Infant, Newborn
• Lung (pathology)
• Nitric Oxide (administration & dosage)
• Oxygen (metabolism)
• Pulmonary Surfactants (administration & dosage)
• Rabbits
• Respiration, Artificial (methods)
• Respiratory Distress Syndrome, Newborn (pathology, physiopathology, therapy)