Raja Srinivasa N, Turnquist Jennifer L, Meleka Sherif, Campbell James N
Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Hospital, Baltimore, MD 21287, USA Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, MD 21287, USA.
Pain. 1996 Jan;64(1):197-204. doi: 10.1016/0304-3959(95)00099-2.
Systemic phentolamine administration has been suggested as a diagnostic tool for identifying patients with sympathetically maintained pain (SMP) (Raja et al. 1991). The dose of phentolamine to produce adequate blockade of peripheral alpha-adrenoceptor function has, however, not been previously determined. In this study, the effects of two different doses of phentolamine on peripheral sympathetic vasoconstrictor function were investigated. One-hundred and seventeen (117) patients with chronic extremity pain underwent 130 phentolamine diagnostic tests using two different doses of phentolamine (0.5 mg/kg over 20 min (n = 60) and 1 mg/kg over 10 min (n = 59)). Eleven (11) patients did not receive phentolamine during the test. Cutaneous temperature was measured in the distal extremity before and after administration of phentolamine. In a subset of patients, baseline blood flow and sympathetically mediated vasoconstrictor response (SMR) to deep inhalation were measured on glabrous skin using laser Doppler flowmetry. SMR was elicited with a 5-sec maximal inspiratory gasp. A dose-related increase in cutaneous temperature was observed. In addition, baseline blood flow increased and SMR was attenuated after both doses of phentolamine, but to a greater degree after the 1 mg/kg dose. However, SMR was not completely attenuated, even after administration of the higher phentolamine dose. These results indicate that a phentolamine dose of 1 mg/kg over 10 min more completely blocks alpha-adrenoceptor function than a dose of 0.5 mg/kg over 20 min. We therefore recommend that to ensure adequate alpha-adrenoceptor blockade the higher phentolamine dose be used in the phentolamine diagnostic test for SMP.
全身给予酚妥拉明已被提议作为一种诊断工具，用于识别患有交感神经维持性疼痛（SMP）的患者（拉贾等人，1991年）。然而，此前尚未确定产生外周α-肾上腺素能受体功能充分阻滞所需的酚妥拉明剂量。在本研究中，研究了两种不同剂量的酚妥拉明对外周交感神经血管收缩功能的影响。117例慢性肢体疼痛患者使用两种不同剂量的酚妥拉明（20分钟内给予0.5mg/kg（n = 60）和10分钟内给予1mg/kg（n = 59））进行了130次酚妥拉明诊断试验。11例患者在试验期间未接受酚妥拉明。在给予酚妥拉明前后测量远端肢体的皮肤温度。在一部分患者中，使用激光多普勒血流仪在无毛皮肤上测量基线血流和对深吸气的交感神经介导的血管收缩反应（SMR）。通过5秒的最大吸气喘息诱发SMR。观察到皮肤温度呈剂量相关增加。此外，两种剂量的酚妥拉明给药后，基线血流增加且SMR减弱，但1mg/kg剂量后减弱程度更大。然而，即使给予较高剂量的酚妥拉明，SMR也未完全减弱。这些结果表明，10分钟内给予1mg/kg的酚妥拉明剂量比20分钟内给予0.5mg/kg的剂量更能完全阻断α-肾上腺素能受体功能。因此，我们建议在用于SMP的酚妥拉明诊断试验中，为确保充分的α-肾上腺素能受体阻滞，应使用较高剂量的酚妥拉明。
