The Amsterdam infant ventilator and the Ayre T-piece in mechanical ventilation

Keuskamp and the Amsterdam Infant Ventilator

At the First International Symposium on the History of Modern Anaesthesia (1982), Professor Keuskamp mentioned that the introduction of breathing machines for lung ventilation during operations had taken over 'the tiresome handwork of ventilation'. This paper traces some aspects of Keuskamp's professional career and his role in the development of the Amsterdam Infant Ventilator. In 1974, Urban and Weitzner from the State University of New York reported that the ventilator was a reliable and effective constant-volume paediatric ventilator. Other clinicians from the United States and Europe echoed this satisfactory clinical evaluation. At present, this paediatric ventilator is still in use for the initial ventilation of small infants and for the mechanical ventilation of different animal species in a variety of experimental settings.

High-frequency positive-pressure ventilation (HFPPV) in neonates and infants during neuroleptal analgesia and routine plastic surgery, and in postoperative management

The low pulmonary compliance, the high airway resistance and the "rapid" breathing pattern of neonatal and paediatric patients make it necessary to design special ventilators to match the pulmonary physiology of infants. A ventilator system which also in small children has a negligible compression volume was evaluated in a lung model and during repair of cleft lip and palate in 16 patients under general anaesthesia and in two other infants during other operations. High-frequency positive-pressure ventilation (HFPPV) was given with an insufflation frequency (f) of 60 per min and a relative insufflation time (t%) of 32%. In addition, two neonates treated postoperatively with HFPPV are reported. Despite the "open" character of the ventilator system both intra- and postoperative ventilation were uneventful in all patients. The arterial oxygenation was good in all cases, as judged from clinical signs or blood gas analyses. Postoperative ventilation required conventional clinical observation and intermittent analyses of blood. HFPPV has been shown to depress, or abolish, spontaneous respiration via reflex mechanisms. In all patients in this investigation respiratory movements were absent at normo- or slight hyperventilation during HFPPV.