Ventilators in the Intensive Care Unit

The earliest ventilator, the Fell-O'Dwyer apparatus, was described in 1892.^[374] It was used as early as 1896 to provide respiratory support in cases of opium poisoning. Rudolph Matas, a surgeon in New Orleans who contributed significantly to the early development of regional anesthesia in the United States, was one of the first to use the Fell-O'Dwyer ventilator during thoracic surgery.^[375] During the polio epidemic, thousands of afflicted patients were kept alive with the Drinker respirator,^[376] often referred to as the iron lung, a negative-pressure device that surrounded the patient and provided for air movement in and out of the lungs. A Swedish ventilator called the Spiropulsator was introduced in 1934 and modified in 1947 by E. Trier Moerch.^[377] This ventilator used a piston pump to deliver a fixed volume of gas. Ventilators today are usually an integral part of the anesthesia machine and direct compressed air into a rigid container containing a bellows that inflates the lungs. Bjørn Ibsen^[378] (1915-), a Danish anesthesiologist, initiated the concept of intensive care units in the early 1950s to care for polio patients and guided the transition from iron lungs to modern ventilators. Intensive care units have since become an integral part of the modern hospital, with anesthesiologists actively involved in their daily operation.