Correction of orthostatic hypotension by respiratory effort

Case report.

To describe a role for breathing in maintenance for blood pressure in a tetraplegic man.

Veterans Administration Hospital, USA.

A 60-year-old man, tetraplegic for 14 years, was successfully treated for orthostatic hypotension (OH) by raising the head of his bed in the mornings before transfer to his wheelchair. To test the role of breathing in the compensation for OH, we monitored the nasal airflow with a thermistor clipped onto a naris and pulse pressure was measured with a transducer held against a supraorbital artery with an elastic band. On raising the head of the bed to 30 degrees the pulse pressure fell and breathing effort increased. Within 1 min, however, pulse pressure rose to baseline levels whereas increased breathing effort continued. On transfer to his wheelchair OH was avoided and medication was unnecessary.

For the tetraplegic subject the partial raising of the head of the bed for a period of time to be determined individually will recruit increased breathing effort and venous return to the chest, preventing OH on transfer to an upright position in a wheelchair.