RT Journal Article
SR Electronic
T1 Severity of ventilator induced lung injury does not contribute to ventilator induced diaphragmatic dysfunction
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4643
VO 40
IS Suppl 56
A1 Christian Bruells
A1 Kathy Reiss
A1 Ashley Smuder
A1 Matthew Hudson
A1 Bradley Nelson
A1 Stefan Uhlig
A1 Scott Powers
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P4643.abstract
AB Mechanical ventilation (MV) is a life-saving intervention for patients with respiratory failure. Even 12h of MV can promote diaphragmatic contractile dysfunction and atrophy (referred to as ventilator-induced diaphragmatic dysfunction, VIDD).The pathophysiology remains unclear but could be linked to inactivity, the physiological impact of positive pressure ventilation (PPV) on the diaphragm and/or ventilator-induced lung injury (VILI).We tested the hypothesis, if negative pressure ventilation (NPV) compared to PPV will diminish VIDD.The concomitant influence of VILI on VIDD was also examined.Rats were ventilated with either PPV or NPV or breathed spontaneously (control) for 12h.We measured diaphragmatic contractile properties, fiber size and markers of oxidative damage. Lungs were histologically examined and cytokine levels were assayed in bronchoalveolar lavage for evidence of VILI.Compared to control, both PPV and NPV resulted in significant oxidative damage to the diaphragm along with fiber atrophy and contractile dysfunction. No significant differences existed in these measures between PPV and NPV groups. Both the PPV and NPV groups experienced VILI, graded by histologic scores or cytokines. Note, that the severity of VILI varied between animals within both the PPV and NPV groups. Nonetheless, the severity of VILI was not significantly correlated with the degree of VIDD.Both PPV and NPV promote VIDD and VILI. The magnitude of VILI is not correlated with the degree of VIDD. Although these findings do not eliminate the possibility that VILI may play a role in VIDD, our results are consistent with the concept that diaphragmatic inactivation as major contributor to VIDD.