tion the tube may connect only to an oxygen
source without a ventilator.
THE IRON LUNG
One of the first mechanical ventilators was nick-
named the iron lung. This device, which used a
vacuum pump within a sealed chamber to cause
the chest to rise, debuted during the POLIOMYELITIS
epidemics of the 1930s and 1940s. Though cum-
bersome (it encased the person from toes to
neck), the iron lung saved countless lives.
Complications of short-term mechanical venti-
lation are usually minor and may include sore
throat (from the endotracheal tube) and INFECTION.
Infection is a greater risk with long-term mechani-
cal ventilation, with PNEUMONIA being the most
common. The longer a person receives mechanical
ventilation, the more difficult it becomes to wean
the person to breathe independently. Long-term
mechanical ventilation becomes an element of life
support, which raises questions of QUALITY OF LIFE.
Doctors encourage adults to establish advance
directives to help guide life-support decisions.
See also ACUTE RESPIRATORY DISTRESS SYNDROME
(ARDS); CARDIOPULMONARY BYPASS; OXYGEN SATURATION.
middle lobe syndrome See ATELECTASIS.
middle lobe syndrome 215