X3.3 Invasive ventilation (intubation)

NIV is contraindicated in patients who are unable to protect their airways, are not spontaneously breathing or who have severe facial injury or burns (Esteban 2000). Relative contrain­dications (situations where NIV may be less effective) include life-threatening refractory hypoxaemia (PaO2 < 60 mmHg, or 8 kPa on 100% inspired oxygen), bron­chiectasis with copious secretions, severe pneumonia, and haemodynamic instability. These patients may require intu­bation. Patients who need mechanical ventilation have an inpatient mortality of up to 39% (Wildman 2009). A multi-centre Spanish study (Rivera-Fernandez 2006) that followed surviving patients for 6 years found that subsequent mortality was related to age, Acute Physiology And Chronic Health Evaluation (APACHE) score and quality of life. Although quality of life deteriorated over time, 72% of the survivors remained self sufficient [evidence level III-2]. A multi-centre UK study (Wildman 2009) that followed surviving patients up to 180 days found that 80% rated their quality of life unchanged compared to pre-admission and 96% would elect to receive the same treatment again under similar circumstances. Overall patients’ functional capacity was slightly reduced at 180 days, but broadly predicted by, pre-admission function. Doctors’ prediction of survivors’ quality of life was pessimistic and agreed poorly with their patients rating.

Weaning from invasive ventilation can be facilitated by the use of non-invasive  ventilation. In a Cochrane meta-analysis of patients with predominantly COPD, the use of non-invasive ventilation for weaning resulted in decreased mortality (RR 0.55, 95% CI 0.38 to 0.79), reduced ventilator-assisted pneumonia (RR 0.29, 95% CI 0.19 to 0.45), reduced length of stay in ICU (WMD -6.27 days, 95% CI -8.77 to -3.78)  and reduced hospital length of stay (WMD -7.19 days, 95% CI -10.8 to -3.58) (Burns 2013).

The patient’s wishes regarding intubation and resuscita­tion should ideally be documented before an admission for management of respiratory failure. Patients who require ventilatory support during exacerbations of COPD may have impaired control of breathing or apnoeas during sleep, even when well. Therefore, performing a diagnostic sleep study when the patient’s condition is stable should be considered. Narcotic analgesics and sedatives should be avoided, as these may worsen ventilatory failure and hasten the need for positive pressure ventilation.