LAUSR

T he polio virus struck Copenhagen suddenly in 1952. Thousands of children fell ill, while hundreds developed impending respiratory failure. Standard management for these patients relied upon negative pressure ventilation via “iron lungs,” which are mechanical respirators weighing more than 500 lbs. However, Copenhagen lacked sufficient iron lungs to care for all the children unable to breathe on their own. Moreover, physiology research in the 1940s implied that this technology failed to remove adequate quantities of carbon dioxide, contributing to acid-base imbalances and, occasionally, patient death. At the same time, small case studies suggested the promise of a new technique: positive pressure ventilation. Henri Lassen, the chief physician at BlegdamHospital, struggled to attend to these Danish children amid a frighteningly high mortality rate: 27 of the 31 patients admitted with bulbar polio had already died. With the urging of his senior registrar Mogens Bjørneboe and armed with the physiological knowledge of anesthesiologist Bjørn Ibsen, Lassen instituted a program of positive-pressure ventilation. Lacking endotracheal tubes, all these children received a tracheostomy. Without ventilators, hundreds of medical workers and students volunteered to breathe for the children manually, spending a cumulative 165,000 hours hand-bagging patients. This intervention demonstrably saved lives: mortality decreased from more than 90% to less than 25%. More importantly, it fundamentally reshaped not only the treatment of polio but also the broader management of respiratory distress. Positive pressure ventilation has since become standard of care, with the subsequent advent of increasingly complex machines designed for this purpose. Examples like this one highlight the potential of pandemics to transform the practice of medicine—in this instance, to promote the development of one of the most essential techniques and tools of critical care medicine. Oftentimes, medical responses to epidemics and pandemics echo innovations seen in wartime. The same sense of emergency drives scientists to work assiduously toward a common goal, mandates cooperation among previously competitive parties, loosens regulations, and provides significant monetary and material resources. Examples of war catalyzing medical modernization include the mass production of penicillin in World War II, rapid advances in vascular surgery in the Korean War that averted thousands of limb amputations, the deployment