Carl-Gunnar Engström

Carl Gunnar Engström (1912 – 1987) was a Swedish physician and engineer

Engström was inventor of the first positive pressure mechanical ventilator with efficient control of the gas volume delivered to the patient and also allows for active exhalation and allowed the delivery of inhalation anaesthetics. He was a pioneer on the use of ventilators in thoracic surgery and intensive care

The Engström universal respirator; one of the early intensive care ventilators to deliver intermittent positive pressure ventilation as well as inhalational anaesthetics. Engström’s invention is credited largely for its use in the treatment of severe respiratory failure secondary to polio which saw it supersede the iron lungs during the polio epidemic of the 1950s in Europe. 

  • Born on Sept 1, 1912 in Oskarshamn, Sweden
  • 1941 – MD, Karolinska Institutet; commences work at Epidemisjukhuset, Municipal Hospital for Infectious Diseases in Stockholm
  • 1950 – designs and develops the Engström universal ventilator after treating a patient suffering from poliomyelitis, recognising the need to build a machine capable of providing controlled insufflation volume and active expiration.
  • 1951 – Engström respirator patented US2699163A; Respirator used for the first time at Blegdams Hospital.
  • 1953 – Copenhagen polio epidemic; 55 cases of bulbo-spinal respiratory paralysis admitted to the Hospital for Infectious Diseases in Stockholm between July and November were treated with tracheotomy and the Engström respirator; publishes original article on his ventilator as ‘Respirator enligt ny princip
  • 1954 – the ventilator is formally launched with his BMJ publication in English – ‘Treatment of severe cases of respiratory paralysis by the Engström Universal Respirator.’; commercial production of the Engström respirator occurs by the Swedish company Mivab (now part of the Datex / Ohmeda division of General Electric Health Care)
  • 1956 – works in the Swedish Airforce
  • 1961 – completes PhD in medicine at Uppsala University with a thesis on ‘the clinical application of prolonged controlled ventilation mechanical ventilation’, published in full in 1963 in Acta Anaesthesiologica Scandinavica
  • Died January 9, 1987 in Stockholm, Sweden

Medical Eponyms
The Engström respirator (1953)

The poliomyelitis epidemic that ravaged Sweden during 1949 and 1950 became the inspiration for the Engström ventilator where high mortality from respiratory paralysis brought to the forefront the inadequacies of the current generation of negative pressure respirators – the iron lung.

In order to make it possible to apply the suggested prone postural drainage in cases of bulbar poliomyelitis accompanied by respiratory paralysis, a new aggregate for artificial respiration also applicable to the prone position was constructed. This unit gives active exhalation but also can be synchronised to give active inhalation by the use of a face mask or a tracheal cannula

Engström 1954 BMJ

The Engström respirator is a double circuit, piston type ventilator that could provide both positive and negative pressure in the airways during inspiration and expiration respectively. It was volume cycled and incorporated a water manometer to monitor airway pressures and thus lung mechanics. It could function as both an anaesthesia machine or ICU ventilator.

…it was recognised that these body respirators were not sufficient for artificial respiration of severe cases, especially with regard to proper elimination of carbon dioxide. At this point I started trials with intermittent insufflation, and it soon became clear that the unfavourable influence of (purely inspiratory) positive-pressure breathing on the circulation could be avoided by completing the respiratory cycle with an active expiration…

Engström 1954 BMJ

The Engström ventilator was first described in the BMJ in 1954 and touted as a ‘universal respirator.’ Seven mechanical and physiological requirements for the universal application of a ventilator to treat severe respiratory paralysis were described by Engstrom in his paper:

If a respirator is to have universal application in treating even severe respiratory paralysis, it must satisfy the following requirements: (1) exercise great ventilatory action; (2) produce uniform pulmonary ventilation; (3) act in such a way that no difficulty of synchronization occurs with the patient’s spontaneous breathing; (4) produce adequate ventilation without harmful effects on the circulation; (5) its method of operation should not be harmful to the elasticity of the lung tissue; (6) its application should be independent of the patient’s posture; and (7) it should produce a high degree of relative humidity in the respiratory gas administered directly into the air passages.

Engström 1954 BMJ

The Engström ventilator however was not truly universal. It was exceptionally large and expensive compared to other ventilators at the time; it was overlooked for smaller ventilators in patients requiring prolonged periods of ventilation as these could be easily tucked away at the bedside; lastly, the Engstrom ventilator was technologically more complex to operate. 

Major Publications



Eponymous terms


Emergency registrar at Sir Charles Gairdner Hospital, Perth

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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