Published online Feb 4, 2016. doi: 10.5492/wjccm.v5.i1.65
Peer-review started: August 10, 2015
First decision: September 16, 2015
Revised: October 8, 2015
Accepted: December 10, 2015
Article in press: December 11, 2015
Published online: February 4, 2016
Processing time: 169 Days and 17.7 Hours
Several clinical and experimental studies have shown that lung injury occurs shortly after brain damage. The responsible mechanisms involve neurogenic pulmonary edema, inflammation, the harmful action of neurotransmitters, or autonomic system dysfunction. Mechanical ventilation, an essential component of life support in brain-damaged patients (BD), may be an additional traumatic factor to the already injured or susceptible to injury lungs of these patients thus worsening lung injury, in case that non lung protective ventilator settings are applied. Measurement of respiratory mechanics in BD patients, as well as assessment of their evolution during mechanical ventilation, may lead to preclinical lung injury detection early enough, allowing thus the selection of the appropriate ventilator settings to avoid ventilator-induced lung injury. The aim of this review is to explore the mechanical properties of the respiratory system in BD patients along with the underlying mechanisms, and to translate the evidence of animal and clinical studies into therapeutic implications regarding the mechanical ventilation of these critically ill patients.
Core tip: Clinical and experimental evidence supports that preclinical lung injury occurs shortly after brain damage. Brain-damaged patients exhibit altered respiratory system mechanics and hypoxemia, even in the absence of clinically evident lung injury. Measurement of respiratory mechanics in such patients may reveal brain damage related lung injury early enough, and facilitate selection of the appropriate ventilator settings to avoid ventilator induced lung injury. Lung protective ventilation, consisting of low tidal volume and moderate levels of positive end-expiratory pressure, may prevent a further deterioration of respiratory dysfunction, and could be possibly associated with improved outcome.