The Direct Effects of Norepinephrine Administration on Pressure Injuries in Intensive Care Patients: A Retrospective Cohort Study.

OBJECTIVE: To estimate the direct effects of norepinephrine administration on pressure injury (PI) incidence in intensive care patients. METHODS: This is a secondary and exploratory analysis of a retrospective cohort study of intensive care patients discharged in 2017 to 2018. Observational cases only included patients who received primary PI preventive care during intensive care (N = 479). As a first-choice vasopressor drug, norepinephrine administration was approximated with days of norepinephrine. Linear path models were examined from norepinephrine administration to PI development. The identification of confounding variables and instrumental variables was grounded on directed acyclic graph theory. Direct effects were estimated with instrumental variables to overcome bias from unobserved variables. As models were re-specified with data analysis, the robustness of path identification was improved by requiring graph invariance with sample split. RESULTS: Norepinephrine caused PI development from one stage to another after 4.0 to 6.3 days of administration in this cohort as a total effect (90% CI). The direct effect was estimated to advance the stage of PI at a rate of 0.140 per day of norepinephrine administered (standard error, 0.029; P < .001). The direct effect accounted for about 70% of the total effect on PI development. CONCLUSIONS: Estimations with instrumental variables and structural equation modeling showed that norepinephrine administration directly and substantially affected hospital-acquired PI incidence in intensive care patients in this cohort.

Singular Predictors of Hospital-Acquired Pressure Injuries Under Intensive Care: A Retrospective Cohort Study in a Medium-Complexity Hospital.

A retrospective cohort study of hospital-acquired pressure injuries (HAPI) reported an incidence rate of 34.3% based on 582 medical records of adult patients admitted to the intensive care unit (ICU) of a medium-complexity public hospital in 2017 and 2018. Sixty percent of the patients used respirators, 49.3% presented hypotension, and 48.1% used norepinephrine. The main individual predictors of HAPI in the ICU were "days of norepinephrine" with an odds ratio (OR) of 1.625 (95% CI: 1.473-1.792) and concordance statistic (AUC) of 0.818 (95% CI: 0.779-0.857), "days of mechanical ventilation" with an OR of 1.521 (1.416-1.634) and AUC of 0.879 (0.849-0.909), "ICU stay (days)" with an OR of 1.279 (1.218-1.342) and AUC of 0.846 (0.812-0.881), and "Braden's sensory perception" with an OR of 0.345 (95% CI: 0.278-0.429) and AUC of 0.760 (0.722-0.799). The duration of mechanical ventilation, norepinephrine administration, and ICU length of stay presented significant discriminative capacity for HAPI prediction.