Mandatory ethics consultation is automatically activated whenever predefined institutional criteria are met. Medical and surgical ICUs differ substantially in case mix, illness trajectories, and decision-making dynamics. Evidence comparing the effects of mandatory ethics consultation across these two settings remains sparse. This study was designed to assess how compulsory ethics consultation influences resource consumption, the frequency and resolution of ethical disputes, and family satisfaction among critically ill patients in medical versus surgical intensive care units, and to determine the key predictors of these outcomes. This study employed a hybrid retrospective–prospective cohort design and was performed at a university-affiliated tertiary referral hospital. All adult patients admitted to intensive care units who received a clinical ethics consultation (CEC) from January 1, 2013, to December 31, 2020, were considered for inclusion. The final sample consisted of 1,150 individuals: 822 managed in the medical ICU and 328 in the surgical ICU. After the adoption of compulsory CEC, overall resource consumption in both units fell progressively every two years. Patients in the medical ICU had markedly longer total hospital stays, more days on mechanical ventilation, and a longer delay between ICU admission and CEC compared to their surgical counterparts. In the medical ICU, the presence of metastatic or terminal malignancy and episodes of cardiac arrest were the dominant drivers of extended stay and greater resource demands, while in the surgical ICU, the Glasgow Coma Scale (GCS) score was the strongest independent predictor. Over the study period, the frequency of documented ethical conflicts declined steadily every two years in both settings. Paradoxically, the surgical ICU recorded higher overall rates of ethical disputes. In the medical ICU, risk factors for ethical conflict included advanced age, incurable cancer, vasopressor/inotrope requirement, and lower GCS scores. In the surgical ICU, only marital status and GCS score consistently predicted such conflicts. Across both units, family members expressed strong satisfaction with the performance and support provided by the ethics consultation service. The introduction of mandatory CECs affected medical and surgical ICUs differently in terms of resource utilization and the types of ethical challenges encountered. These findings can help ethics consultants and clinical teams tailor their approaches to the unique needs of each specialty. Institutions may benefit from adopting mandatory CEC policies and creating specialty-specific education and training initiatives to enhance the quality of end-of-life care provided in intensive care settings.
