ASA Physical Status, Anesthetic Technique, and ICU Admission After Elective Surgery in Older Adults: A Prospective Multicenter Indonesian Cohort

Abstract

Background. Postoperative intensive care unit (ICU) beds are scarce in Indonesia while the number of older surgical patients grows.

Objective. We quantified postoperative ICU admission among older adults undergoing elective surgery and its association with American Society of Anesthesiologists (ASA) physical status and anesthetic technique.

Methods. Prospective cohort of consecutive patients aged ≥60 years undergoing elective non-cardiac surgery in 15 Indonesian tertiary hospitals (February–April 2021). Proportions with Wilson 95% confidence intervals (CI), exact and trend tests were computed from the recorded outcome-by-predictor tables. Because predictors were not cross-classified, adjusted associations were bounded across all 4,207,140 datasets consistent with the recorded margins and within clinically plausible limits.

Results. Of 893 patients, 168 (18.8%; 95% CI 16.4–21.5) were admitted to the ICU. Admission rose from 10.4% in ASA II to 31.5% in ASA III and 84.6% in ASA IV (trend p<0.001); the adjusted odds ratio (OR) for ASA III versus II was at least 2.84 in every admissible dataset. Admission was 23.0% after general and 10.6% after regional anesthesia (crude OR 2.51, 95% CI 1.66–3.79). The ASA-adjusted OR ranged from 0.95 to 243 across all datasets, but from 1.82 to 6.74 when general-anesthesia use differed by ≤20 percentage points between ASA strata; with comorbidity added, the lowest value found was 1.34. ASA ≥III identified 63.7% of admissions.

Conclusion. ASA physical status is robustly associated with postoperative ICU admission in older Indonesians. Excess admission after general anesthesia persists under plausible case-mix scenarios but cannot be separated from the unrecorded surgical procedure.