In-flight stabilization of oxygen saturation by control of altitude for severe respiratory insufficiency.
A 4,907-mile medical air transport recently took place between Vancouver, Canada, and London, England. The patient was a 6-year-old boy with multiple pleural, pulmonary, and pericardial hemangiomata who required heart-lung transplant. Because his respiratory function was so poor (including oxygen-induced hypercarbia and sleep-induced hypoxia), a Lear 35 was used. The aircraft made a low altitude flight possible, allowing adjustment of cabin pressure to overcome the child's sensitivity to any significant reduction in partial pressure and to minimize his need for supplemental oxygen. Clinical observation and monitoring using oximetry and transcutaneous blood gas measurements were carried out en route to warn of excessive altitude effects. Sequential increases in altitude were made once oxygenation had stabilized at each cabin pressure. Cabin pressure was not allowed to rise above 3,700 ft to ensure an oxygen saturation level of at least 80%. The transport was accomplished successfully with no requirement for intervention. This approach to in-flight management has applications for other aero-medical transports.