血液透析動靜脈壓合理上限值

Acceptable Limits of Venous and Arterial Pressures during Hemodialysis

血液透析機不但可偵測並顯示透析時幫浦之前動脈負壓和靜脈壓，同時，在壓力超過或低於設定值時會對透析護理人員發出警告。有關動、靜脈壓合理上限值的知識與瞭解，不僅幫助護理同仁正確地判斷機器所顯示的動、靜脈壓力值，而且也提供了血液透析病患高品質的照顧。然而，動、靜脈壓力上限值的設定於每一透析室卻有著極大的不同。在台灣，不知甚麼原因，幾乎所有廠牌的血液透析迴路管都不配備動脈壓力偵測，也不知從何時起，有關靜脈壓錯誤的認知，存在於大部份透析護理同仁，不管用幾號針或是甚麼血液流量透析，大家都將靜脈壓上限值設定在200mmHg，透析中護理同仁都竭盡所能地讓病患的靜脈壓低於200mmHg。（例如：把靜脈針改成比動脈針尺寸大的針，一再重覆穿刺靜脈，調降血流量等等。）若是每一透析中心能夠設定屬於自己透析室的合理動、靜脈壓力上限值讓護理同仁有所依循，就不會出現過於保守甚至不當的處置，而造成病患不適與透析不足。本文將簡介有關較高的動、靜脈壓力值形成原因與衍生問題並討論動靜脈壓的合理上限值。

Hemodialysis machines are able to measure and display arterial (pre-pump) and venous pressures as well as to warn the operator when these pressures fluctuate outside of an established alarm limit. The knowledge of acceptable pressure limits enables the nursing staff to interpret these pressure readings correctly and provide quality care to hemodialysis patients. However, these limits on pressures are very different in every hemodialysis unit. In Taiwan, for unknown reasons, almost all brands of hemodialysis blood lines are not equipped with arterial pressures monitoring. Moreover, it is unclear as to how long these misunderstandings about venous pressure have been occurring. Most of the nursing staff take 200mmHg as an acceptable upper limit of venous pressure, no matter what gauge of needles or what velocity of blood flow are prescribed. They do whatever they can do to keep venous pressure under 200mmHg during dialysis (e.g. increase venous needle size, repeat venous needle cannulation, reduce blood flow, etc). If every dialysis unit sets up its own limits on venous pressures for staff, it won't come out that the nursing staff conduct some too conservative or even inappropriate procedures to cause patents' discomforts and inadequacies of dialysis. We shall review the acceptable limits of arterial and venous pressures, and the etiologies and associated problems regarding higher arterial and venous pressures.