In August 2018, Wilson and colleagues published the results of a systemic review and meta-analysis in Critical Care Medicine titled “Noninvasive Ventilation in Patients With Do-Not-Intubate and Comfort-Measures-Only Orders: A Systematic Review and Meta-Analysis.”
The analysis focused on:
- the impact of non-invasive ventilation (NIV) on the survival, quality of life, and tolerance of treatment for patients with acute respiratory failure and a do-not-intubate (DNI) status, and
- tolerance of treatment, survival, dyspnea control, and opioid requirements for patients receiving NIV treatment for acute respiratory failure in patients with comfort measures only (CMO) status.
The analysis included 27 eligible studies of DNI (2,020 patients) and another 3 studies of CMO (200 patients). In patients with DNI orders, the survival rate was 56% (95% CI, 49–64%) at hospital discharge and 32% (95% CI, 21–45%) at 1 year. There was no significant difference for patients treated in a ward versus the ICU and based on the available data, the quality of life for survivors was not lowered by comparison to baseline. Only one study evaluated dyspnea control in patients with CMO status and found that the impact of NIV treatment was statistically significant only in cases of hypercapnia (PCO2 > 45 mm Hg) (p = 0.045). CMO status patients treated with NIV also received fewer opioids within the first 48 hours compared to patients treated with just oxygen (26.9 vs 59.3 mg; mean [95% CI] difference, –32.4 [–47.5 to –17.4] mg).
Tolerance of NIV for DNI patients was largely good, with just one study reporting only 32% of patients tolerated it and six studies reporting 77-96% of patients tolerated it. The two studies that reported tolerance of NIV for CMO patients indicated that 9.7-11.1% of patients were taken off the therapy due to intolerance. In one study 76.4% of patients reported poor sleep while on NIV.
The authors note limitations of their analysis, including the high risk for bias of the studies they reviewed, stemming from factors like small sample sizes, observational studies, and single-center trials. However, they also state that the meta-analysis shows the benefit of NIV treatment for patients in acute respiratory failure on DNI orders, demonstrating that contrary to some experts’ views, this treatment does not merely prolong the dying process.
Although several questions remain unanswered, this meta-analysis indicates that NIV may be a useful and tolerable tool for clinicians treating respiratory failure patients on DNI orders — particularly for patients receiving NIV to manage COPD or Cardiogenic Pulmonary Edema.
While Wilson and colleagues’ review did not assess any tools other than NIV, it may be of interest to note that a recent multi-center, randomized controlled trial demonstrated that High Velocity Nasal Insufflation (HVNI) is noninferior to NIV/NIPPV in the treatment of undifferentiated respiratory distress. This randomized, controlled trial also found that clinicians rated HVNI more highly than NIV in terms of patient comfort and clinicians’ ease of use.
Learn more about treating undifferentiated respiratory distress with a nasal cannula
 Wilson ME, Majzoub AM, Dobler CC, et al. Noninvasive Ventilation in Patients With Do-Not-Intubate and Comfort-Measures-Only Orders: A Systematic Review and Meta-Analysis. 2018:1209-1215.
 Doshi P, Whittle JS, Bublewicz M, et al. High-Velocity Nasal Insufflation in the Treatment of Respiratory Failure: A Randomized Clinical Trial. Ann Emerg Med 2018;72:73-83 e5.