Intramuscular deltoid pressure during shoulder arthroscopy.

A large amount of fluid extravasation into the surrounding muscle and soft tissue may occur during arthroscopy of the shoulder and particularly of the subacromial space. The tense swollen appearance of the shoulder has caused concern that the intramuscular deltoid pressure may become elevated to dangerous levels. Therefore, the intramuscular deltoid pressure was monitored in this study using a slit catheter. Although it was found that the intramuscular pressure became transiently elevated during the arthroscopic procedures, in every case the pressures promptly returned to normal levels within 30 min postoperatively. The clinical swelling and tenseness remained for a longer period. Despite a sometimes alarming amount of swelling during shoulder arthroscopy, intramuscular pressure elevations were only sustained for a short time and returned to normal levels very quickly after the cessation of fluid infusion.