Comparisons of nursing hours and nurse-to-patient ratios required for patients with mechanical ventilation, CRRT, and ECMO in intensive care units: A cross-sectional study

Objectives: To examine nurse staffing requirements in intensive care units (ICUs) for mechanical ventilation (MV), continuous renal replacement therapy (CRRT), extracorporeal membrane oxygenation (ECMO), and their combinations, and analyze the effects of these procedures on staffing requirements across different types of ICU stay. Methods: A cross-sectional study was conducted to analyze data from patients discharged from adult ICUs at a tertiary hospital in Seoul, South Korea, between 2022 and 2023. Staffing requirements were evaluated using nursing hours per patient day (NHPPD) and nurse-to-patient ratios. Each ICU day was categorized into one of eight procedure groups: none of three procedures, one-procedure (MV, CRRT, or ECMO), two-procedure (MV & CRRT, MV & ECMO, or CRRT & ECMO), and three-procedure (MV, CRRT, & ECMO) groups. The impacts of these groups on NHPPD were analyzed using multilevel regression models. Results: Among a total of 51,226 ICU days from 8,541 patients, the MV group accounted for the largest proportion of ICU days (44.4%), followed by the no-procedure group (38.2%). The overall NHPPD was 14.8 h, with a nurseto-patient ratio of 1:1.6. The no-procedure group had the lowest NHPPD (12.8 h), while the three-procedure group had the highest (18.9 h). The overall NHPPD was highest on continuing-stay days, whereas two- and three-procedure groups tended to have the highest NHPPD on admission days. In multiple regression analyses, the three-procedure group exhibited the greatest increase in NHPPD (4.94 h), followed by the MV & CRRT group (4.42 h) and the MV & ECMO group (3.28 h), compared to the no-procedure group. Conclusions: Staffing requirements varied among procedure groups and types of ICU stay. The NHPPD for combined procedures exceeded the sum of the NHPPD for the individual procedures. Implications for Clinical Practice: Staffing requirements should be tailored to meet the increasing patient needs resulting from procedural complexity.