Outcomes of Older Adults Admitted to the ICU Following Trauma: A Scoping Review Identifying the Nonagenarian Evidence Gap.

As populations age, trauma-related intensive care unit (ICU) admissions among older adults are increasing, including nonagenarians who are increasingly offered ICU-level care. However, ICU outcomes for nonagenarians remain essentially undescribed, and existing trauma literature largely aggregates patients aged 65 years and older without age-specific analyses of the oldest cohorts. This scoping review sought to characterize ICU outcomes after traumatic injury in elderly and oldest adults, and to determine whether any evidence specifically addresses nonagenarians. We conducted a scoping review following the Arksey-O'Malley framework and the PRISMA-ScR guidance. MEDLINE (Ovid), the Cochrane Library, and gray literature sources were searched from inception to April 10, 2025. Studies were eligible if they reported mortality outcomes for adults aged ≥65 years admitted to the ICU following trauma. Data on age thresholds, injury severity scores (ISS), intubation, ICU length of stay, complications, surgical procedures, and trauma mechanisms were extracted by one reviewer and independently verified by a second. Given substantial clinical and methodological heterogeneity, findings were summarized using descriptive statistics only; a sample-size-weighted average mortality was calculated as a descriptive summary measure. Of 226 records screened, 7 retrospective cohort studies met the inclusion criteria. No study analyzed nonagenarians (≥90 years) as a distinct subgroup; included cohorts were defined using thresholds of >65, >70, >75, or >80 years. In-hospital mortality ranged from 3.9% to 20.2% across heterogeneous elderly ICU trauma populations, with higher mortality consistently observed in patients with higher ISS and those experiencing unplanned ICU admission or ICU readmission. A sample-size-weighted average in-hospital mortality of 10.5% was observed across all studies; this value is descriptive and must be interpreted cautiously in view of variations in age structure, injury patterns, admission criteria, and eras of care. Falls were the predominant trauma mechanism (44.8%-67.3%), followed by motor vehicle collisions. Median ISS ranged from 9 to 19, and median ICU length of stay from 2 to 10 days, with longer stays associated with mechanical ventilation and complications such as respiratory failure, pneumonia, and sepsis. Intubation rates ranged from 5% to 61%, and surgical intervention rates from 0.8% to 30.7%, most commonly chest drainage and orthopedic procedures. Current evidence on ICU outcomes after trauma in elderly patients is derived from heterogeneous cohorts aged ≥65-80+ years and does not provide nonagenarian-specific data. Within these broader elderly ICU trauma populations, higher ISS and unplanned ICU admission are consistently associated with increased in-hospital mortality, and respiratory complications are common. However, the absence of dedicated analyses for patients aged ≥90 years, the lack of long-term functional and quality-of-life outcomes, and the retrospective design of all available studies substantially limit inferences for nonagenarians. Future research should prioritize prospective, age-stratified cohorts including nonagenarians, incorporate frailty and baseline function as key prognostic variables, and report standardized mortality and functional outcomes to inform ICU triage, prognostication, and resource allocation for the oldest trauma patients.