4 ERS Practical Handbook Noninvasive Ventilation Introduction single limb of tubing, meaning that the carbon dioxide in the exhaled breath was rebreathed, which could eventually result in asphyxiation. Fortunately, Heinrich’s son Bernard redesigned the circuitry with two sets of tubing, one for inhalation, the other for exhalation, which solved that problem this modification went into production and 30 years later, the 12 000th Pulmotor rolled off the production line in Lubeck. The Pulmotors were supplied to mines for poisoning accidents, to deal with victims of fires and for other acute uses. This is crucial, as the stimulus for ventilator use had been entirely for ARF up to this point. It was not until the 1970s and 1980s that long-term chronic use began to be the spur to ventilatory progress. This was partly related to better understanding of the physiology of breathing during sleep, the rediscovery of sleep apnoea and CPAP therapy, and underlying global trends in the switch from acute to chronic healthcare. OSA is associated with recurrent episodes of upper airway obstruc- tion, which can lead to a number of vascular complications if not addressed, but which Sullivan showed in 1981 could be effectively treated with CPAP, as the air- flow splints the airway open. In addition, developments in masks and technology extended NIV to respiratory failure in patients with neuromuscular disease. The original CPAP machines were very large – about the size of a vacuum cleaner – but have improved, and become smaller and portable over time. Importantly, mask design and comfort have improved too. To complete the timeline, the devel- opments from the end of the 1980s to the present are shown in figure 3. A great deal of progress has occurred such that NIV is now one of the most evidence-based areas of respiratory medicine, as this handbook will describe. Really significant interventions are the discovery and confirmation by RCT that NIV halves mortality and morbidity in acute exacerbations of COPD, and this Chronic Acute 1980s 1990s Late 1990s 2000 2005 2014 CPAP, neuromuscular disease NIV in restrictive disorders Improved outcome in Duchenne MD NIV in motor neurone disease Paediatric NIV NIV in acute COPD NIV in acute hypoxaemic respiratory failure, pulmonary oedema and weaning NIV in chronic COPD Figure 3. Timeline of developments in NIV from the 1980s to the present day. MD: muscular dystrophy.