Epidemiology and age-related mortality in critically ill patients with intra-abdominal infection or sepsis: an international cohort study.

OBJECTIVE

To describe epidemiology and age-related mortality in critically ill older adults with intra-abdominal infection.

METHODS

A secondary analysis was undertaken of a prospective, multi-national, observational study (Abdominal Sepsis Study, ClinicalTrials.gov #NCT03270345) including patients with intra-abdominal infection from 309 intensive care units (ICUs) in 42 countries between January and December 2016. Mortality was considered as ICU mortality, with a minimum of 28 days of observation when patients were discharged earlier. Relationships with mortality were assessed by logistic regression analysis.

RESULTS

The cohort included 2337 patients. Four age groups were defined: middle-aged patients [reference category; 40-59 years; n=659 (28.2%)], young-old patients [60-69 years; n=622 (26.6%)], middle-old patients [70-79 years; n=667 (28.5%)] and very old patients [≥80 years; n=389 (16.6%)]. Secondary peritonitis was the predominant infection (68.7%) and was equally prevalent across age groups. Mortality increased with age: 20.9% in middle-aged patients, 30.5% in young-old patients, 31.2% in middle-old patients, and 44.7% in very old patients (P<0.001). Compared with middle-aged patients, young-old age [odds ratio (OR) 1.62, 95% confidence interval (CI) 1.21-2.17], middle-old age (OR 1.80, 95% CI 1.35-2.41) and very old age (OR 3.69, 95% CI 2.66-5.12) were independently associated with mortality. Other independent risk factors for mortality included late-onset hospital-acquired intra-abdominal infection, diffuse peritonitis, sepsis/septic shock, source control failure, liver disease, congestive heart failure, diabetes and malnutrition.

CONCLUSIONS

For ICU patients with intra-abdominal infection, age >60 years was associated with mortality; patients aged ≥80 years had the worst prognosis. Comorbidities and overall disease severity further compromised survival. As all of these factors are non-modifiable, it remains unclear how to improve outcomes.