Onizuka Chisato, Niimi Yuki, Sato Motohiko, Sugenoya Junichi
Department of Physiology, Aichi Medical University, Nagakute, Aichi, 480-1195, Japan,
Environ Health Prev Med. 2015 Jul;20(4):262-70. doi: 10.1007/s12199-015-0455-5. Epub 2015 Apr 17.
High tolerance to postural changes was examined in nurses.
Twelve female nurses and 12 healthy controls underwent a 70° head-up tilt (HUT) test for 10 min. Blood pressure (BP), heart rate (HR), pulse pressure, and hormone levels were measured. Baroreceptor sensitivity (BRS) was calculated using a sequence technique.
HR increased during HUT in both subject groups, with no difference between groups. Systolic BP was rapidly increased by HUT in both subject groups, and was higher in the nurse group than in the control group during the first 2 min of HUT. Pulse pressure decreased during 1-2.5 min of HUT in the control group, but there was no decrease in the nurse group. BRS was decreased by HUT in the nurse group, while it tended to be decreased in the control group. Both during baseline and HUT, BRS was lower in the nurse group than in the control group. Plasma noradrenaline increased with HUT, and the increase was greater in the nurse group than in the control group.
Although nurse subjects had a lower BRS during HUT than control subjects, they were able to effectively maintain BP during HUT, suggesting that nurse subjects had higher orthostatic tolerance. The better maintenance of BP in nurse subjects appeared to be associated with a compensatory mechanism other than the arterial baroreflex and/or a hemodynamic mechanism.
研究护士对体位变化的高耐受性。
12名女性护士和12名健康对照者进行了70°头高位倾斜（HUT）试验，持续10分钟。测量血压（BP）、心率（HR）、脉压和激素水平。采用序列技术计算压力感受器敏感性（BRS）。
两组受试者在HUT期间HR均升高，组间无差异。两组受试者在HUT期间收缩压均迅速升高，且在HUT的前2分钟内护士组高于对照组。对照组在HUT的1 - 2.5分钟内脉压下降，但护士组无下降。护士组的BRS在HUT时降低，而对照组有降低趋势。在基线期和HUT期间，护士组的BRS均低于对照组。血浆去甲肾上腺素随HUT升高，且护士组升高幅度大于对照组。
尽管护士受试者在HUT期间的BRS低于对照受试者，但他们在HUT期间能够有效维持血压，提示护士受试者具有更高的直立耐受性。护士受试者血压的更好维持似乎与除动脉压力反射和/或血流动力学机制之外的代偿机制有关。
