@article {Granchi1555, author = {Thomas Granchi and Ashley Lemere and Neil Mashruwala and Colette Galet and Kathleen S Romanowski}, title = {Increased Ratio of Dead Space to Tidal Volume in Subjects With Inhalation Injury}, volume = {65}, number = {10}, pages = {1555--1560}, year = {2020}, doi = {10.4187/respcare.07515}, publisher = {Respiratory Care}, abstract = {BACKGROUND: Inhalation injury increases morbidity and mortality in burn patients. Patients with inhalation injury present with large differences between end-tidal CO2 pressure and , an indirect measure of dead space. We aimed to investigate the relationships between increased dead space and inhalation injury outcomes.METHODS: This retrospective study included 51 adult subjects with burns and inhalation injuries. Demographics, size of burns, length of stay, ventilator days, blood gas results, end-tidal CO2 pressure, presence of ventilator-associated pneumonia, and mortality data were collected. Modified Baux scores and ratios of alveolar dead space to alveolar tidal volume (/) were calculated. Independent t tests were used to compare mean / of survivors to that of subjects who died and between subjects with and without pneumonia. The relationships between / and ventilator days or modified Baux score were assessed with bivariate correlation analysis.RESULTS: Our population had a mean age of 52 y and an average burn size of 17.5\%. The average length of stay and ventilator days were 12 d and 3.8 d, respectively. The mean modified Baux score was 87. The mean / was 0.38. Ten subjects died, and 6 subjects had pneumonia. The / of survivors was significantly smaller for survivors than for subjects who died (0.34 vs 0.52, P = .03). No significant difference was observed between subjects with and without pneumonia (0.36 vs 0.47, P = .26). / correlated significantly with modified Baux score (r = .524, P \< .001).CONCLUSIONS: Alveolar dead space (/) is easily calculated from and end-tidal CO2 pressure and may be useful in assessing severity of inhalation injury, the patient{\textquoteright}s prognosis, and the patient{\textquoteright}s response to treatment.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/65/10/1555}, eprint = {https://rc.rcjournal.com/content/65/10/1555.full.pdf}, journal = {Respiratory Care} }