Abstract P37: Pulmonary Dysfunction is Common After Cardiac Arrest
Objectives: Pulmonary injury following out of hospital cardiac arrest (OHCA) is common but incompletely described. We sought to characterize and determine the incidence of chest x-ray (CXR) abnormalities and pulmonary dysfunction in patients after OHCA.
Methods: Retrospective chart review of patients suffering OHCA between 1–1– 05 and 12–31– 08 was performed after IRB approval. Radiology interpretations of initial and 24-hour CXR abnormalities were recorded. Clinical data included use of hypothermia, antibiotic treatment, PaO2/FiO2 ratio obtained within 8 hours of the CXR, and survival to discharge. The PaO2/FiO2 ratio was coded as severe pulmonary dysfunction (SPD; PaO2/FiO2<200), moderate pulmonary dysfunction (MPD; PaO2/FiO2 201–300), or normal (PaO2/FiO2>300). Statistical comparisons between groups were assessed using Chi-squared analyses.
Results: Of 207 subjects, 201 (97.1%) had an initial CXR, 183 (88.4%) had repeat CXR, 128 (61.8%) had initial blood gas values, 83 (40.1%) had repeat blood gas values, and 87/198 (43.9%) patients survived to discharge. On initial CXR, 128 (61.8%) patients presented with an abnormality, including pulmonary edema (27.1%), atelectasis (20.4%), and consolidation (15.4%). SPD was initially present in 54/128 (42.2%) patients with 38/83 (45.8%) on repeat ABG. MPD was present in 22/128 (17.2%) patients and 21/83 (25.3%) on repeat ABG. In patients receiving hypothermia therapy (N=111, 54%), there were no differences in CXR abnormalities compared to normotheric patients (59% vs. 41%, χ2=1.86, p=0.17). Consolidation (27% vs. 10%, χ2=7.96, p<0.01) was more common on repeat CXR in the hypothermic cohort. Neither MPD nor SPD was more common in hypothermic patients than normothermic patients (MPD: 20% vs. 12%; SPD: 45% vs. 37%; χ2=11.5, p=0.22). Patients with consolidation on initial CXR were treated with antibiotics in 15/31 (48.4%) cases.
Conclusions: Lung injury after OCHA is common. SPD develops in over 40% of patients after OCHA. Hypothermic patients are more likely to demonstrate a consolidation on 24-hour CXR, but did not demonstrate increased rates of SPD or MPD. There is variability in clinical use of antibiotics in OHCA with consolidations on CXR.