Baraff L J, Schriger D L
Department of Pediatrics, University of California-Los Angeles School of Medicine.
Am J Emerg Med. 1992 Mar;10(2):99-103. doi: 10.1016/0735-6757(92)90038-y.
The authors conducted this study to: (1) determine the effect of age on orthostatic vital signs; and (2) to define the sensitivity and specificity of alternative definitions of "abnormal" orthostatic vital signs in blood donors sustaining an acute 450-mL blood loss. The population studied were 100 healthy adult volunteer blood donors and 100 self-sufficient ambulatory citizens attending a senior citizens daytime activity center. Subjects with a history of orthostatic hypotension were excluded. Subjects were first placed in the recumbent position and their rate pulse and blood pressure were determined after 1 minute; these same parameters were measured in the same arm beginning 30 seconds after standing. In blood donors measurement of orthostatic vital signs was repeated immediately after blood donation. Blood donors served as their own controls in the determination of sensitivities and specificities. Mean orthostatic vital sign changes were as follows: pulse rate, 2 +/- 7 beats per minute; systolic blood pressure, -3 +/- 9 mm Hg; and diastolic blood pressure, 1 +/- 7 mm Hg. There was no clinically meaningful variance in orthostatic blood pressure changes with age. For a given specificity, pulse rate increase was the most sensitive of the orthostatic vital signs used alone; a pulse rise of greater than 20 beats per minute had a sensitivity of 9% with a specificity of 98%.(ABSTRACT TRUNCATED AT 250 WORDS)
（1）确定年龄对直立位生命体征的影响；（2）明确在急性失血450毫升的献血者中，“异常”直立位生命体征的替代定义的敏感性和特异性。研究人群包括100名健康成年志愿献血者和100名在老年人日间活动中心活动的能独立行走的市民。有直立性低血压病史的受试者被排除。受试者首先被置于卧位，1分钟后测定其心率和血压；站立30秒后，在同一手臂测量相同参数。献血者在献血后立即重复测量直立位生命体征。在确定敏感性和特异性时，献血者自身作为对照。直立位生命体征的平均变化如下：心率，每分钟2±7次；收缩压，-3±9毫米汞柱；舒张压，1±7毫米汞柱。直立位血压变化在不同年龄之间无具有临床意义的差异。对于给定的特异性，单独使用时，心率增加是最敏感的直立位生命体征；心率上升大于每分钟20次时，敏感性为9%，特异性为98%。（摘要截选至250字）
