Published in:
Open Access 01-12-2013 | Research article
Age-related differences in symptoms, diagnosis and prognosis of bacteremia
Published in: BMC Infectious Diseases | Issue 1/2013
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Background
Elderly patients are at particular risk for bacteremia and sepsis. Atypicalpresentation may complicate the diagnosis. We studied patients withbacteremia, in order to assess possible age-related effects on the clinicalpresentation and course of severe infections.
Methods
We reviewed the records of 680 patients hospitalized between 1994 and 2004.All patients were diagnosed with bacteremia, 450 caused by Escherichiacoli and 230 by Streptococcus pneumoniae. Descriptiveanalyses were performed for three age groups (< 65 years,65–84 years, ≥ 85 years). In multivariate analyses age wasdichotomized (< 65, ≥ 65 years). Symptoms werecategorized into atypical or typical. Prognostic sensitivity of CRP and SIRSin identifying early organ failure was studied at different cut-off values.Outcome variables were organ failure within one day after admission andin-hospital mortality.
Results
The higher age-groups more often presented atypical symptoms (p <0.001),decline in general health (p=0.029), and higher in-hospital mortality(p<0.001). The prognostic sensitivity of CRP did not differ between agegroups, but in those ≥ 85 years the prognostic sensitivity oftwo SIRS criteria was lower than that of three criteria. Classical symptomswere protective for early organ failure (OR 0.67, 95% CI 0.45-0.99), andrisk factors included; age ≥ 65 years (OR 1.65, 95% CI1.09-2.49), comorbid illnesses (OR 1.19, 95% CI 1.02-1.40 per diagnosis),decline in general health (OR 2.28, 95% CI 1.58-3.27), tachycardia (OR 1.50,95% CI 1.02-2.20), tachypnea (OR 3.86, 95% CI 2.64-5.66), and leukopenia (OR4.16, 95% CI 1.59-10.91). Fever was protective for in-hospital mortality (OR0.46, 95% CI 0.24-0.89), and risk factors included; age ≥ 65years (OR 15.02, 95% CI 3.68-61.29), ≥ 1 comorbid illness (OR2.61, 95% CI 1.11-6.14), bacteremia caused by S.pneumoniae (OR 2.79, 95% CI 1.43-5.46), leukopenia (OR 4.62,95% CI 1.88-11.37), and number of early failing organs (OR 3.06, 95% CI2.20-4.27 per failing organ).
Conclusions
Elderly patients with bacteremia more often present with atypical symptomsand reduced general health. The SIRS-criteria have poorer sensitivity foridentifying organ failure in these patients. Advanced age, comorbidity,decline in general health, pneumococcal infection, and absence of classicalsymptoms are markers of a poor prognosis.