Historical background

In the early 1950s an outbreak of poliomyelitis in Scandinavia highlighted for the first time the need for hospital units specialised in treating episodes of acute respiratory failure. The first intensive care units (ICUs), at that time utilising non-invasive techniques such as tank ventilators, were therefore built in Northern Europe. Later on positive pressure ventilation via an endotracheal tube or a tracheotomy became common and the modalities of non-invasive ventilation were progressively abandoned.1 Insertion of an endotracheal tube is usually performed after sedation and paralysis of the patient, and for this reason for many years mechanical ventilation was the exclusive field of anaesthetists so that in many European countries ICUs are still run mainly by anaesthetists rather than “organ specialists”. This clinical and management background has also conditioned respiratory medicine in Europe, and only a few European countries include specific training in emergency medicine and mechanical ventilation as part of the programme of the specialisation in respiratory medicine.2 This is not the case in North America where intensive care medicine has been closely linked to respiratory medicine for many years. In the middle of the 1960s, following the pioneering experience of Dr Petty,3 a growing number of specialised respiratory intensive care units (RICUs) started to spread all over the USA alongside, and not in competition with, “general” ICUs.4 The RICUs were designed to treat acute or acute-on-chronic respiratory failure due to any pulmonary disease with monitoring systems equal to those of the ICUs. These units necessitated a specialised environment and personnel, with increasing costs, so that in the 1980s a new class of “step down” or “intermediate” critical care units, the so-called non-invasive respiratory care units (NRCU) or high dependency units (HDU)5 were developed as a less costly option for patients receiving long term mechanical …