Objective: To estimate nursing workload from the patient acuity level (PAL) assigned to patients in a pediatric intensive care unit (PICU) and to determine its influence on unplanned extubations.
Design: Prospective cohort study.
Setting: The 19-bed PICU of an urban, university-affiliated, tertiary children's hospital.
Patients: All patients admitted to the PICU.
Measurements and main results: The study encompassed 2,193 nursing shifts and 1,919 admissions to the PICU over 24 months. The shift census averaged 12.0 patients (range 5-18) and was staffed by 9.4 nurses (range 4-16) for an average patient/nurse ratio of 1.3 +/- 0.2. Patients were assigned a PAL of 1-7 based on a classification system derived from time studies of 12 general nursing tasks. The total PALs per shift divided by the number of nursing staff yielded an average assignment of 5.8 +/- 0.7 PALs. Forty unplanned extubations (0.76 unplanned extubations/100 ventilator days) were observed during the study period. Logistic regression revealed positive associations between unplanned extubations and patient/nurse ratio (p = .03) and the shift PAL/nurse ratio (p = .01). The likelihood of an unplanned extubation when nurses covered >6.3 PALs was 3.8 times higher than during those shifts when they covered <5.3 PALs.
Conclusions: The likelihood of an unplanned extubation increased with higher patient/nurse and patient acuity/nurse ratios. Successful interventions to reduce the frequency of this medical error may need to address both nurse demand methodology and workload.