Does the application of an algorithm for non-invasive ventilation in chronic obstructive pulmonary disease improve the initiation process and patient outcomes?

Objectives - Non-invasive ventilation (NIV) for acute hypercapnic respiratory failure in chronic obstructive pulmonary disease (COPD) has been shown to decrease endotracheal intubation and mortality; however, little guidance exists on NIV initiation. This study aimed to explore patient outcomes and the process of NIV initiation following the introduction of an algorithm.

Design - Prospective, modified time-series study. Baseline measures were performed during the control period and repeated in the algorithm phase.

Setting - Acute secondary care teaching hospital, wherever NIV was commenced (accident and emergency, medical assessment unit, thoracic medicine unit).

Participants - Thirty-four patients with COPD and acute hypercapnic respiratory failure.

Interventions - An algorithm was devised for use when initiating NIV, highlighting four aspects of care from the evidence base: synchronisation, tidal volume, oxygenation and comfort.

Main outcome measures - Arterial pH value, Borg scale rating of breathlessness, and a staff questionnaire on the process of NIV initiation.

Results - No significant difference was found in changes in pH or Borg score. However, three of the four aspects of care promoted by the algorithm were reported more frequently in the intervention phase. Increased assessment of tidal volume (5/17 cases in control phase, 95% confidence interval 0.05 to 0.54; 12/17 cases in algorithm phase, 95% confidence interval 0.46 to 0.95) reached statistical significance (P=0.038, Fisher's exact test).

Conclusions - This study presents an algorithm to assist the application of NIV, and has demonstrated changes in practice following its introduction. It is proposed that the algorithm is considered for use within services that initiate NIV. Further work is required to explore the effects of staff education and the promotion of ownership.