Fundamentals of artificial ventilation of the lung

Abstract

HISTORY OF ARTIFICIAL VENTILATION Artificial ventilation of the lungs can be performed without any equipment at all. Early descriptions of resuscitation include the use of expired air ventilation, which was used in victims of drowning. This involved manipulation of the arms to expand the thorax and draw air into the lungs but has been superseded by ‘the kiss of life’ with ventilation using expired air. However, as long ago as 1788, Kite of Gravesend described oral and nasal intubation for the resuscitation of the apparently drowned patient. In 1871 Trendelenberg anaesthetized a patient through a tracheostomy wound and occluded the trachea with an inflatable cuff but it was Langton Hewer who, in 1939, reintroduced the concept of the pilot tube. In 1934 Guedel and Treweek introduced artificial ventilation of the lungs into anaesthesia and in 1936 Waters first used the term ‘controlled respiration’. Guedel and Treweek controlled breathing using deep ether anaesthesia to raise the threshold of the respiratory centre. Controlled ventilation was greatly facilitated by the development of muscle relaxants. Much of this work in the UK was done by Gray and Rees in Liverpool and resulted in the so-called ‘Liverpool Technique’ of anaesthesia. During the 1950s in Sweden there was a major epidemic of poliomyelitis. Medical students were paid to help with the ventilation of these patients and this event helped to speed up the development of mechanical ventilators. USES OF ARTIFICIAL VENTILATION Artificial ventilation of the lungs is used on a daily basis across the world, predominantly as part of an anaesthetic technique associated with muscular paralysis. Assisted ventilation is mainly used within intensive care units as a means of life support whilst recovery from disease or injury is awaited. Cardiopulmonary resuscitation also relies upon artificial ventilation until spontaneous respiration is restored. An infrequent but important use of artificial lung ventilation is for patients who have problems from which they are unlikely to recover and for whom artificial ventilation is a lifelong necessity.