Article

OBJECTIVE: To compare responses to head-up tilt (HUT) in individuals with chronic
tetraplegia after midodrine hydrochloride (10 mg) versus nitro-L-arginine methyl
ester (L-NAME, 1 mg/kg) administration. DESIGN: Prospective comparative drug
trial. SETTING: Veterans Affairs medical center. PARTICIPANTS: Participants (N=7)
were studied during 3 laboratory visits: no drug, midodrine (administered orally
30 min before HUT), and L-NAME (infused over a 60-min period). INTERVENTIONS:
Anti-hypotensive agents, midodrine, and L-NAME. MAIN OUTCOME MEASURES: Mean
arterial pressure (MAP), cerebral blood flow (CBF), and markers of the
renin-angiotensin-aldosterone system (RAAS, plasma renin and serum aldosterone)
were measured in the supine position at baseline (BL) and during a 45 degrees HUT
maneuver. Data were compared between BL and the average of 3 assessments
collected during HUT. RESULTS: Orthostatic MAP and CBF were increased with the
midodrine and L-NAME groups compared with the no drug trial and the relationship
between the change in MAP and CBF was significant (r=0.770; P<0.001). Both L-NAME
and midodrine appeared to suppress the post-HUT RAAS response compared with no
drug. CONCLUSIONS: Increasing orthostatic blood pressure with L-NAME or midodrine
appears to increase CBF and suppress the RAAS during HUT in persons with
tetraplegia, although more data are needed to confirm these preliminary findings.
CI - Copyright (c) 2011 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS