Clinical features and outcomes of patients with hospital acquired pneumonia in a 12-month service evaluation project of a UK cohort

RationaleHospital Acquired Pneumonia (HAP) is a significant burden on patients worldwide, representing an estimated 28.1% of hospital acquiredinfections. It is defined as a lung infection in a non-intubated patient with new infiltrates on X-ray >48hours after hospital admission. HAPis thought to have high morbidity and mortality, though there is little published literature regarding demographics, clinical features,prognostic factors and outcomes. This service evaluation project reviewed all HAP cases admitted to Heart of England NHS Trust hospitalsin 2013 and aimed to establish clinical features and outcomes.
MethodAll patients diagnosed with HAP in Heart of England NHS trust in 2013 were identified using the hospital coding system. For each case, thechest X-ray (including radiologist’s report) and patient notes were reviewed to confirm HAP diagnosis. Cases not meeting HAP diagnosticcriteria were excluded. Data was subsequently collected regarding demographics, co-morbidities, blood-test results, and outcomes.
Results293 cases of HAP were identified using the coding system, 141 patients were excluded due to absence of new infiltrates on chest x-ray; 11patients were excluded as the diagnosis was made within 48 hours of hospital admission. Of the remaining 141 cases, mean age was 81.6years (range 52-98). Mean number of co-morbidities was 5; only one patient had no co-morbidities. 133(94.3%) cases had available pastmedical history 41(30.8%) had respiratory co-morbidities; 37(27.8%) had COPD, 7 (5.3%) had asthma, 3(2.3%) had Interstitial Lung Disease,2(1.5%) had lung cancer, 3(2.3%) had bronchiectasis, 2(1.5%) had chronic pleural effusion.Blood test results from day of diagnosis were available for 138(98%). Mean hemoglobin was 110.87g/L, 121(85.8%) were anemic. MeanWCC was 13.68x109/L. Mean CRP was 120.9mg/L. Mean urea was 10.5mmol/L.Sixty-four cases (44%) died during admission; a further 32(22.6%) died within a year of admission, indicating an overall mortality rate of67% for the first year post-diagnosis. Mean inpatient stay was 24.8 days (range 1-104). Raised blood urea was significantly associated withdeath during admission (P=0.002). Age >65 years was not significantly associated with death during admission (p=0.159), nor was numberof co-morbidities.
ConclusionThe vast majority of HAP patients were over 65 and had multiple co-morbidities, though age >65 and number of comorbidities was notlinked to subsequent mortality. Those with raised urea were significantly more likely to die during admission. Further study is warranted toidentify those at risk of HAP and to identify predictors of the associated mortality and morbidity.