Karen Swecker, RN, MedFlight Infection Control Liaison
Ventilators have become a common piece of equipment in healthcare, saving lives and providing respiratory assistance for those who may be depending on it to stay alive. Like most equipment in healthcare someone saw a need and started work on coming up with a solution.
The ventilator has a history that begins in the 16th century by Andreas Vesalius, who at the age of 23 taught anatomy. Due to his dissection of human cadavers, his ideas were greatly frowned upon by the church. In 1543, Vesalius published a series of books on the human anatomy, describing a tracheotomy and blowing air into the hole to cause the lungs to “rise again”. Prior to Vesalius, common belief was that the act of breathing caused the heart to beat.
In 1667, scientist Robert Hook demonstrated that blowing air into the lungs kept one alive. However, it still wasn’t clear why people breathed or why they became pulseless. The most common belief was that people became unconscious due to a lack of stimulation. Treatment for this included rolling the person over barrels, putting them over a trotting horse, hanging them upside down, or using a fumigator that blew smoke up the rectum.
During the 1730s, a Scottish surgeon, Wm. Tossach successfully resuscitated a coal miner with mouth to mouth breathing, describing the process in medical literature. The process included pinching the nose and blowing as hard as he could into the patient’s mouth. Once the patient regained a pulse the doctor “pushed, pulled, and rubbed” the patient to stimulate circulation. Mouth to mouth resuscitation became popular until oxygen was discovered in the 1770s. The belief was that any exhaled air was depleted of oxygen therefore mouth to mouth was of no use to a person in respiratory distress.
Ventilators based on negative pressure were developed in the late 1800s.
In 1876, the first iron lung was developed and place along the Seine River to save drowning victims. The first iron lung to treat polio victims was used in Boston in 1929. One difficulty with the iron lung was figuring out how to access the patient’s body for care. To solve this a respirator room was created where the patient’s body lay inside the room with the head sticking out. Pistons were used to create pressure changes causing air to move in and out of the lungs. Multi patient ventilation rooms were developed for use during polio epidemics.
During the 1940s and 1950s, positive pressure invasive ventilation was developed which provided volume controlled ventilation. There were no alarms or monitors and no specific settings. Total volume was measure separately. Soon, a double circuit ventilator was used in both OR and ICU, it included monitoring for pressure and tidal volume, and machine triggered inspiration. In the 1960s, PEEP became standard care. By the early 1970s, second generation ventilators monitored tidal volume, respiratory rate and allowed patient triggered inspiration. Improvements continued at a fast past, developing into the ventilators now in use. Speculation of the future of ventilators include the ability of the ventilator to integrate with other bedside technology, smart alarms, and decision support.
The ventilator has come a long way in a short time.