Titrated oxygen therapy compared to high‐flow oxygen therapy for acute exacerbations of chronic obstructive pulmonary disease

Patient or population: adults with acute exacerbations of chronic obstructive pulmonary disease
Setting: pre‐hospital setting
Intervention: titrated oxygen therapy
Comparison: high‐flow oxygen therapy

Mortality (respiratory‐ related and all‐cause

RR 0.22
(0.05 to 0.97)

214
(1 RCT)

⊕⊕⊝⊝
LOW ^{1, 2}

A difference in mortality was observed, with 11 deaths in the high‐flow oxygen arm compared to two deaths in the titrated oxygen arm (P = 0.05). This translates to a number needed to treat for an additional beneficial outcome (NNTB) of 14 (95% CI 12 to 355) with administration of titrated oxygen therapy, and is shown as a Cates plot in Figure 1. All deaths occurred after arrival at the hospital; two were in intensive care. Respiratory failure was the cause of mortality in all cases, with approximately 70% of deaths occurring within the first five days following admission for both treatment arms.

Arterial blood gas (pH)

‐

214
(1 RCT)

⊕⊕⊝⊝
LOW ^{1, 2}

Based on the intention‐to‐treat analysis for the COPD subgroup, no significant difference between treatment arms for blood gas measurements was observed between groups (P = 0.23). Only 11% of participants had this measurement performed according to protocol.

Ventilation of any type

RR 0.67
(0.29 to 1.55)

189
(1 RCT)

⊕⊕⊝⊝
LOW ¹

No significant difference observed between treatment arms for ventilation requirement for per protocol or intention‐to‐treat analyses.

Length of hospital stay

‐

214
(1 RCT)

⊕⊕⊝⊝
LOW ^{1, 2}

No significant difference was observed between treatment arms in length of hospital stay for the intention‐to‐treat analysis (P = 0.21).

Quality of life ‐ not measured

‐

‐

‐

This was not reported as an outcome in the single included study.

Lung function ‐ not measured

‐

‐

‐

This was not reported as an outcome in the single included study.

Dyspnoea score ‐ not measured

‐

‐

‐

This was not reported as an outcome in the single included study.

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: confidence interval; RR: risk ratio; MD: mean difference

GRADE Working Group grades of evidence
High certainty: We are very confident that the true effect lies close to that of the estimate of the effect
Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect
Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect