Factors affecting thirty-day mortality in patients diagnosed with pneumonia in the emergency department

Pneumonia is an inflammatory condition of the lung that occurs as a result of inadequate host defenses and the consequent spread of different pathogenic microorganisms into the lower respiratory tract. It ranks first among the causes of mortality due to infectious diseases in all age groups. Shock index (SI), modified shock index (mSI), age-related shock index (ASI) and respiratory-related shock index (RASI) scores calculated using vital signs have been the subject of several studies and have been associated with severity and mortality in various diseases. The fact that pneumonia is an important health problem, is frequently seen in the community and has a high mortality rate shows the importance of determining the factors affecting mortality and predicting mortality. The aim of our study was to determine the factors affecting mortality in patients admitted to the emergency department (ED) and diagnosed with pneumonia, and to determine the importance of these factors on 30-day mortality. This single-center, prospective, cross-sectional analytical study was conducted in Pamukkale University, Department of Emergency Medicine, between February 2023 and January 2024. Demographic information, mode of admission, whether the patient was a nursing home resident or not, complaints on admission, comorbidities and drug treatments, state of consciousness, vital signs, SI, mSI, ASI, RASI values, laboratory parameters, imaging results if obtained, length of stay in the ED were noted. The study outcome was mortality within 30 days of admission. Of the 378 patients admitted with the diagnosis of pneumonia 35.2% were female. The mean age of the patients was 70,28±12,94. The most common complaint was shortness of breath (69%), followed by cough (63.2%), sputum (39.4%), fever (36.5%), weakness (29.1%), chest pain (12.7%), and confusion (12.2%). The most common comorbidity was hypertension with 40.7%, followed by diabetes mellitus (27%), chronic obstructive pulmonary disease (24.1%), malignancy (22.8%), and the others. The mean systolic blood pressure was 133.08±29.10 mmHg, mean diastolic blood pressure was 72.84±15.06 mmHg, mean pulse rate was 102.34±21.07 beats/min, mean respiratory rate was 24.61±6.94 breaths/min, mean body temperature was 36.75±0.6 ºC and mean fingertip O2 saturation was 89.75±7.14%. The mean SI was calculated as 0.81±0.26, mSI was 1.14±0.34, ASI was 56.80±21.61, and the mean RASI was 2.03±0.98. 81% of the patients were conscious on admission. While 30.2% of the patients were discharged with the recommendation of outpatient treatment, 29.1% were hospitalized in the ward and 37% in the intensive care unit. Of 365 patients who underwent thoracic computed tomography, 115 had lobar and 203 had multilobar pneumonia. Thirty-day mortality rate was 23.5%. SI (O.R: 4,303), mSI (O.R: 3,163), ASI (O.R: 1,020) and RASI (O.R: 1,385) are all valuable parameters in predicting mortality in patients admitted to the ED and diagnosed with pneumonia. In the regression model we created with SI, the presence of sputum (O.R.=1.919), presence of malignancy (O.R.=1.998) and blood urea nitrogen (BUN) values (O.R.=1.024) were found to have an effect on mortality. In the regression model we created with MSI, the presence of sputum (O.R.=1.944), presence of malignancy (O.R.=1.993) and BUN values (O.R.=1.024) were found to have an effect on mortality. In the regression model we created with RASI, the presence of sputum (O.R.=1.891), presence of malignancy (O.R.=2.273), fingertip O2 saturation (O.R.=0.96) and BUN values (O.R.=1.023) were found to have an effect on mortality. In the regression model that we created with the ASI, the presence of sputum (O.R.=1.896), presence of malignancy (O.R.=2.411) and BUN values (O.R.=1.021) were also found to have an effect on mortality. In patients with pneumonia admitted to the ED, we found that each of the SI, mSI, ASI and RASI, which we investigated as our main objective, increased the thirty-day mortality. In addition, presence of sputum, presence of malignancy, BUN value, and fingertip O2 saturation are among the factors that increase mortality.