Research on weaning obese patients from mechanical ventilation has shown mixed results. Early studies linked obesity to prolonged ventilation, while later research, after adjusting for BMI and other biases, found a protective effect, such as faster extubation with no increase in reintubation rates. A recent meta-analysis, however, excluded BMI as a predictor for extubation failure, although higher BMI was associated with successful extubation.
Both noninvasive ventilation (NIV) and high-flow nasal cannula (HFNC) have been shown to benefit obese patients post-extubation. Some studies found that using NIV in post-extubation reduced reintubation rates in obese patients, but a large trial failed to show NIV’s superiority. Several factors contribute to these mixed outcomes, including NIV tolerance, obesity-related risks for respiratory complications, and variability in response depending on the type of respiratory failure (hypercapnic vs. hypoxaemic).
Given this complexity, a recent study aimed to test if prolonged, actively humidified NIV is more effective than HFNC in preventing hypoxaemic extubation failure in obese patients with a BMI ≥30 kg/m² who are at intermediate risk.
The study, conducted in two Spanish ICUs from June 2020 to June 2021, examined the effectiveness of NIV with active humidification versus HFNC in obese patients (BMI >30) who were ready for planned extubation and had three or fewer risk factors for reintubation. Patients with hypercapnia at the end of the spontaneous breathing trial were excluded. Participants were randomised to receive either NIV or HFNC for 48 hours post-extubation. The primary outcome was the reintubation rate within 7 days.
Of the 144 patients, 72 received NIV and 72 received HFNC after extubation. Reintubation was needed in 23.6% of the NIV group and 33.3% of the HFNC group, with a non-significant difference of 9.7% between groups. Secondary analyses also showed no significant differences. However, the analysis suggested a high probability of reduced reintubation with NIV.
Overall, these findings show that in adult obese critically ill patients at intermediate risk for extubation failure, NIV did not significantly reduce the reintubation rate compared to HFNC.
Source: AJRCCM
Image Credit: iStock
References:
Hernández G et al. (2024) Humidified Noninvasive Ventilation versus High-Flow Therapy to Prevent Reintubation in Obese Patients: A Randomized Clinical Trial. American Journal of Respiratory and Critical Care Medicine.
