Mechanical power of ventilation is associated with mortality in neurocritical patients: a cohort study

Abstract

This study aimed to determine the predictive relevance of mechanical power in the clinical outcomes (such as ICU mortality, hospital mortality, 90-day mortality, length of ICU stay, and number of ventilator-free days at day 28) of neurocritical patients. This is a retrospective cohort analysis of an open-access clinical database known as MIMIC–III. The study included patients who had sustained an acute brain injury and required invasive ventilation for at least 24 h. Demographic parameters, disease severity scores (Glasgow coma scale), comorbidities, vital signs, laboratory parameters and ventilator parameters were collected within the first 24 h of ICU admission. The main outcome was the relationship between MP and ICU mortality. A total of 529 patients were selected for the study. The critical value of MP was 12.16 J/min, with the area under the curve (AUC) of the MP was 0.678 (95% CI 0.637–0.718), and compared to the GCS scores, the MP performed significantly better in discrimination (DeLong’s test: p < 0.001). Among these patients elevated MP was associated to higher ICU mortality (OR 1.11; 95% CI 1.06–1.17; p < 0.001), enhanced the risk of hospital mortality, prolonged ICU stay, and decreased the number of ventilator-free days. In the subgroup analysis, high MP was associated with ICU mortality regardless of ARDS (OR 1.01, 95% CI 1.00–1.02, p = 0.009; OR 1.01, 95% CI 1.00–1.02, p = 0.018, respectively) or obesity (OR 1.01, 95% CI 1.00–1.02, p = 0.012; OR 1.01, 95% CI 1.01–1.02, p < 0.001, respectively). In neurocritical care patients undergoing invasive ventilation, elevated MP is linked to higher ICU mortality and a variety of other clinical outcomes.

Utilization of mechanical power and associations with clinical outcomes in brain injured patients: a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

“…Results of a large, prospective multicenter observational study (NCT04459884) are forthcoming [30], and randomized controlled trials (RCTs) are needed to provide more clarity on this topic. Overall, medians and ranges of MP observed in our study were similar to values described in another ABI cohort [16], but lower compared to those described in a large general critical care cohort [12] and a post-cardiac arrest cohort [15], possibly due to higher proportions of lung injury in these populations. Our results also suggest that MP utilization is mainly driven by concomitant lung injury and ARDS.…”

“…Recent studies have demonstrated an association between higher MP and mortality in mixed critical care populations [12], both with [13] and without ARDS [14], and in patients with hypoxemic-ischemic encephalopathy (HIE) after cardiac arrest [15]. However, limited data are available regarding the role of MP in other ABI populations, with only one retrospective, single-center study showing an association between MP in the first 24 h and mortality during the intensive care unit (ICU) stay [16].…”

Neurological and respiratory effects of lung protective ventilation in acute brain injury patients without lung injury: brain vent, a single centre randomized interventional study

“…MP is described as energy delivered to the respiratory system over time. In neurocritical care patients, increased MP may be related to higher ICU mortality [ 40 ]. The present study is the first one to analyse the relationship between MP and cerebral variables in patients with ABI.…”

Ventilatory targets following brain injury

“…Lower MP (<17 J/min) was also associated with reduced mortality in an observational study of patients without ARDS [57]. In the neurologic population, a single-center study including 529 patients with mixed subtypes of ABI found that higher MP was associated with increased ICU mortality in the overall cohort and in subgroups stratified by high vs. low body mass index and presence vs. absence of ARDS [58]. Finally, a secondary analysis of 1848 patients after cardiac arrest found that MP was independently associated with increased 6month mortality (omnibus P-value for nonlinear trajectory ¼ 0.026), but not worse neurologic outcome (OR 1.01, per 1-unit increase in MP; 95% CI 0.99-1.03).…”