Department of Emergency Medicine, University of California, Irvine, CA, USA.
Department of Medicine Statistics Core, University of California, Los Angeles, CA, USA.
J Intensive Care Med. 2020 May;35(5):511-518. doi: 10.1177/0885066618762335. Epub 2018 Mar 7.
In severe circulatory failure agreement between arterial and mixed venous or central venous values is poor; venous values are more reflective of tissue acid-base imbalance. No prior study has examined the relationship between peripheral venous blood gas (VBG) values and arterial blood gas (ABG) values in hemodynamic compromise. The objective of this study was to examine the correlation between hemodynamic parameters, specifically systolic blood pressure (SBP) and the arterial-peripheral venous (A-PV) difference for all commonly used acid-base parameters (pH, Pco , and bicarbonate).
DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Data were obtained prospectively from adult patients with trauma. When an ABG was obtained for clinical purposes, a VBG was drawn as soon as possible. Patients were excluded if the ABG and VBG were drawn >10 minutes apart.
The correlations between A-PV pH, A-PV Pco , and A-PV bicarbonate and SBP were not statistically significant ( = .55, .17, and .09, respectively). Although patients with hypotension had a lower mean arterial and peripheral venous pH and bicarbonate compared to hemodynamically stable patients, mean A-PV differences for pH and Pco were not statistically different ( = .24 and .16, respectively) between hypotensive and normotensive groups.
In hypovolemic shock, the peripheral VBG does not demonstrate a higher CO concentration and lower pH compared to arterial blood. Therefore, the peripheral VBG is not a surrogate for the tissue acid-base status in hypovolemic shock, likely due to peripheral vasoconstriction and central shunting of blood to essential organs. This contrasts with the selective venous respiratory acidosis previously demonstrated in central venous and mixed venous measurements in circulatory failure, which is more reflective of acid-base imbalance at the tissue level than arterial blood. Further work needs to be done to better define the relationship between ABG and both central and peripheral VBG values in various types of shock.
在严重循环衰竭的情况下，动脉和混合静脉或中心静脉值之间的一致性较差；静脉值更能反映组织酸碱失衡。之前没有研究检查过血流动力学障碍时外周静脉血气（VBG）值与动脉血气（ABG）值之间的关系。本研究的目的是检查血流动力学参数（特别是收缩压[SBP]）与所有常用酸碱参数（pH 值、Pco2 和碳酸氢盐）的动脉-外周静脉（A-PV）差值之间的相关性。
设计、地点、参与者和测量：数据是从患有创伤的成年患者中前瞻性获得的。当出于临床目的获得 ABG 时，尽快抽取 VBG。如果 ABG 和 VBG 相隔>10 分钟，则排除患者。
A-PV pH 值、A-PV Pco2 和 A-PV 碳酸氢盐与 SBP 之间的相关性没有统计学意义（分别为=.55、.17 和.09）。尽管低血压患者的平均动脉和外周静脉 pH 值和碳酸氢盐值均低于血流动力学稳定的患者，但低血压和正常血压组之间的 pH 值和 Pco2 的平均 A-PV 差值没有统计学差异（分别为=.24 和.16）。
在低血容量性休克中，外周 VBG 与动脉血相比并未显示出更高的 CO 浓度和更低的 pH 值。因此，外周 VBG 不能替代低血容量性休克时的组织酸碱状态，这可能是由于外周血管收缩和血液向重要器官的中心分流所致。这与之前在循环衰竭时中央静脉和混合静脉测量中观察到的选择性静脉呼吸性酸中毒形成对比，后者更能反映组织水平的酸碱失衡，而不是动脉血。需要进一步研究以更好地定义 ABG 与各种类型休克时中央和外周 VBG 值之间的关系。
