An epidemic overwhelms respiratory care

The Copenhagen poliomyelitis epidemic of 1952 became a turning point in the organization of care for critically ill patients. At Blegdam Hospital, physicians confronted an exceptional concentration of patients unable to breathe adequately or swallow safely. H. C. A. Lassen, who directed the hospital’s response, reported approximately 3,000 admissions with a diagnosis of poliomyelitis during the final five months of the year. That admission figure should not be confused with the number of confirmed or paralytic cases. The hospital initially possessed only one tank respirator and six cuirass respirators. Lassen’s contemporary account.

The emergency continued beyond the epidemic’s peak. Lassen recorded patients still dependent on artificial respiration in April 1953. Survival therefore created obligations extending well beyond initial rescue: sustained nursing, continued respiratory assistance and planning for prolonged disability. The episode belongs to the history of hospital organization and patients’ continuing needs as well as to the history of medical equipment.

Anaesthetic knowledge enters the epidemic ward

Anaesthetist Bjørn Ibsen was consulted in late August 1952. His subsequent report described 31 patients with bulbar poliomyelitis treated in respirators during the preceding three weeks, of whom 27 had died. He brought operating-theatre experience in maintaining an airway and assisting ventilation into an infectious-disease emergency. His approach combined a tracheotomy, a cuffed airway tube and manually delivered positive-pressure ventilation. Ibsen’s report.

A crucial distinction concerned oxygenation and ventilation. In Ibsen’s account, supplemental oxygen could improve a patient’s colour while carbon dioxide continued to accumulate. Moving sufficient air through the lungs was a separate requirement. This helped redirect attention from outward appearance alone toward the adequacy of breathing and the physiological consequences of respiratory failure. The account illustrates how clinical observations challenged assumptions during an emergency; it is a historical description, not a treatment protocol.

A precise anniversary date requires caution. Lassen’s account places the first treatment on 27 August, while other historical accounts have used 26 August. Describing the intervention as occurring in late August preserves the established sequence without concealing disagreement over the day.

Continuous care as an organized service

Manual ventilation required people to remain continuously available at the bedside. Lassen described medical students working in relays alongside a greatly expanded nursing and medical workforce. The response depended on training, supervision and reliable handovers, as well as on the apparatus itself. Lassen’s staffing account.

Erik Wainø Andersen and Ibsen’s joint report described another organizational change: patients considered likely to develop respiratory complications were transferred to special observation wards, where staff recorded their condition. Their account presented the epidemic as the beginning of extensive cooperation between epidemiologists and anaesthetists in Denmark. Andersen and Ibsen’s clinical report.

The historical significance lies partly in this combination of concentrated observation, specialist cooperation and sustained assistance with a failing bodily function. Read together, these reports suggest that the innovation was a service requiring coordinated labour. A breathing device alone could not reproduce the system that made prolonged treatment possible.

Interpreting outcomes and credit

Contemporary reports document severe early mortality and the subsequent adoption of a new treatment system. Andersen and Ibsen also described measures intended to intensify observation and improve results. These were reports of an evolving emergency response, rather than a randomized comparison of otherwise identical patients. Their published account.

Consequently, a historical interpretation should not attribute every change in survival to one isolated intervention. Airway management, ventilation, observation and growing staff experience formed a combined response. Comparisons also require attention to which patients were counted and how long outcomes were followed. These qualifications do not erase the achievement; they make its evidential basis clearer.

Credit likewise extends beyond a single inventor. Louise Reisner-Sénélar’s research, drawing on a patient’s medical record and an interview with Ibsen, emphasizes epidemiologist Mogens Bjørneboe’s role in bringing anaesthetic expertise into the crisis. Its evidence supports treating the breakthrough as collaboration across professional boundaries, while recognizing Ibsen’s distinctive contribution. Research on Ibsen’s records.

From epidemic response to intensive care

The emergency wards of 1952 should be distinguished from the subsequent establishment of a dedicated intensive care unit. Reisner-Sénélar traces a process extending through the epidemic of 1952–1953 to a unit established in Copenhagen in December 1953. This chronology makes the epidemic a formative episode in intensive care, rather than equating every later feature of the specialty with one bedside intervention. Reisner-Sénélar’s historical study.

The broader legacy is the possibility of organizing hospital care around the intensity of a patient’s needs and the sustained support of vital functions. Interpreted in that light, Copenhagen illustrates how an improvised emergency service could point toward a durable institutional form. Its history also keeps patients and bedside workers visible alongside celebrated physicians: prolonged survival depended on continuing care after the dramatic moment of rescue had passed.

For the wider development of respiratory support and critical-care services, see History of Intensive Care and Mechanical Ventilation.

Historical evidence and further reading