Table 2.

Summary of potential consequences of hyperoxia in medical emergencies and recommendations for its avoidance. CPR, cardiopulmonary resuscitation; MI, myocardial infarction.

Medical condition	Potential consequences	Recommendations
Resuscitation and ventilation in neonates	Retinopathy Bronchopulmonary dysplasia	Use of air for resuscitation, and if needed, judicious use of supplementary oxygen guided by pulse oximetry.13
Respiratory failure	Hypercapnia Ventilatory support Acute lung injury	Target Spo2 to 94–98% or 88–92% if patient is considered at risk of hypercapnia2: • COPD with previous hypercapnic respiratory failure • Cystic fibrosis or bronchiectasis • Morbid obesity (BMI >40 kg m−2) • Musculoskeletal disorders associated with respiratory muscle weakness • Therapy with opioids or benzodiazepines.
Myocardial Infarction	Increased infarct size Recurrent MI Arrhythmias	Oxygen should only be administered if there is evidence of hypoxia, but there is no agreement on the absolute definition of hypoxia in this situation. The routine use of oxygen in patients with suspected myocardial infarction and Spo2 ≥90% does not reduce mortality at 1 yr, which suggests that this may be a suitable target.14
Stroke	Increased disability Mortality	Patients who have had a stroke should receive supplemental oxygen only if their Spo2 decreases below 95%. The most recent trial suggests no benefit from oxygen if Spo2 is ≥93%.15
Adult resuscitation	Neurological outcome Survival	Highest possible oxygen concentration during CPR. With return of spontaneous circulation titrate oxygen to Spo2 values of 94–98%.