Early History of Ancient times
Ancient writings by the Egyptians and Greeks described theories of respiration. In the Old testament there is a mention of Prophet Elisha inducing pressure breathing from his mouth into the mouth of a child who was dying–(Kings 4:34-35).
Hippocrates (460-375 BC) wrote the first description of endotracheal intubation his book –‘Treatise on Air’ “One should introduce a cannula into the trachea along the jaw bone so that air can be drawn into the lungs”.
Paracelsus (1493-1541) used ‘Fire Bellows’ connected to a tube inserted into patient’s mouth as a device for assisted ventilation. This was the first study (1550) which credited him with the first form of mechanical ventilation. Vesalius (1543) performed ventilation via a tracheostomy in a pig. Hook (1667) used bellows via a tracheostomy in a dog. John Fathergill in 1744 reported a successful case of ‘mouth to mouth’ resuscitation.
John Hunter developed double bellows for resuscitation in 1775 - one for blowing air in and the other for drawing bad air out. Draeger Medical designed an artificial breathing device“Draeger Pulmoter” in 1911 that was used by fire and police units (see below).
Negative Pressure Ventilators
From the mid 1800-1900s a large number of devices were invented that applied negative pressure around the body or thoracic cavity – these devices became known as negative pressure ventilators or 'iron lungs'. Two successful designs became popular; in one, the body of the patient was enclosed in an iron box or cylinder and the patient’s head protruded out of the end. The second design was a box or shell that fitted over the thoracic area only (chest cuirass). Patients with chronic paralytic disorders were successfully ventilated on this cuirass ventilators at home for 25-30 years.
Scandinavian Polio Epidemic - 1952
Between July-December of 1952, in Copenhagen, 2722 patients with poliomyelitis were treated in the Community Disease Hospital of which 315 patients required ventilatory support. Many principles of IPPV were defined during that time –including the use of cuffed tubes, periodic sigh breaths and weaning by reduction of assisted breaths. Towards the end of the epidemic a few positive pressure ventilators were invented (the Engstrom, Lundi and the Bang) which became popularly known as mechanical students.
Era of Respiratory Intensive Care
After polio epidemics, the 1960’s became an era of respiratory intensive care. Positive pressure ventilation with use of an artificial airway replaced the bulky and cumbersome negative pressure technology of respiratory support. Two types of ventilators and two modes of mechanical ventilation evolved during this period; the first type of ventilator was pressure cycled (PCV).
Two ventilators were commonly used for PCV in the 1960’s and 1970’s; the Bird Mark 7 and the Bennet PR2. The second type of ventilator that evolved from a historical perspective is the volume cycled ventilator – VCV. The first fluidic ventilator utilizing moving streams of liquid or gas for sensing, logic, amplification and controls was designed for the US army in 1964 by Barila and the first commercial versatile fluidic ventilator “Hamilton standard PAD” appeared in 1970. The term ‘weaning’ was used to explain various techniques to test the quality of patient’s spontaneous ventilation before extubation.
A mechanical change of substantial importance in the late 1960’s and early 1970’s that shaped the present era was the introduction of Positive End Expiratory Pressure (PEEP). Two modes of ventilation Assisted Ventilation (AV) and Controlled Mechanical Ventilation (CMV) came together in a single piece of equipment and the modern era of multiple choice respiratory support was born. The introduction of IMV permitted spontaneous respiration in the midst of substantial respiratory failure which paved the way for a means of weaning i.e. SIMV. PSV proved to be an addition to IMV that facilitated spontaneously breathing patients.
100 Years of Artificial Ventilation