Orthostatic Effects of Midodrine Versus L-NAME on Cerebral Blood Flow and the Renin-Angiotensin-Aldosterone System in Tetraplegia

详细信息    查看全文

• 作者：Jill M. Wecht ; EdD^a ; ^b ; ^c ; ^d ; ^{jm.wecht@va.gov" class="auth_mail" title="E-mail the corresponding author} ; Miroslav Radulovic ; MD^a ; ^b ; ^c ; ^d ; Dwindally Rosado-Rivera ; EdD^a ; Run-Lin Zhang ; MD^a ; Michael F. LaFountaine ; EdD^a ; ^c ; William A. Bauman ; MD^a ; ^b ; ^c ; ^d
• 关键词：Blood pressure ; Hypotension ; orthostatic ; Rehabilitation ; Spinal cord injuries
• 刊名：Archives of Physical Medicine and Rehabilitation
• 出版年：2011
• 出版时间：November 2011
• 年：2011
• 卷：92
• 期：11
• 页码：1789-1795
• 全文大小：791 K

文摘

Wecht JM, Radulovic M, Rosado-Rivera D, Zhang RL, LaFountaine MF, Bauman WA. Orthostatic effects of midodrine versus L-NAME on cerebral blood flow and the renin-angiotensin-aldosterone system in tetraplegia.

Objective

To compare responses to head-up tilt (HUT) in individuals with chronic tetraplegia after midodrine hydrochloride (10mg) versus nitro-L-arginine methyl ester (L-NAME, 1mg/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 30min 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° 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.