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Mutual control of breathing and blood pressure: case report
1Research Service, Boston Healthcare Center and Harvard Medical School, Boston, MA, USA.
Study Design:
Trial outcome.
Objectives:
To demonstrate the relationship between circulation and breathing with orthostasis in a tetraplegic man.
Setting:
A long-term care unit at a Veterans Administration Hospital, USA.
Method:
A tetraplegic patient with a history of orthostatic hypotension was monitored for blood flow at the level of the supraorbital artery, for breathing by nasal air flow, and for pulse oxymetry on a tilt table at 0, 45 and 0 degrees of head elevation.
Results:
Tilting up caused a coincidental reduction in blood flow and enhanced breathing. These effects were coincidentally reversed by tilting down. Oxyhemoglobin concentration and pulse rates increased with orthostasis and returned to baseline on tilting down.
Conclusion:
A reciprocal relationship between breathing and circulation has been demonstrated in a tetraplegic patient challenged by orthostasis.
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