Serial overnight recordings of intracarpal canal pressure in carpal tunnel syndrome patients with and without wrist splinting.

In 15 carpal tunnel syndrome patients pressure was measured during the day and at 2-hourly intervals from midnight to 6 a.m., via a catheter introduced into the carpal canal, using the constant infusion technique. Intracarpal tunnel pressure of the patients always exceeded the critical pressure of 30 mmHg and the highest values were found at 6 a.m. Slightly lower pressures were found when the wrist was splinted, but the difference was not significant, nor were critical pressure levels prevented by splinting.