Janssen Joost W, van Fessem Joris M K, Ris Tijmen, Stolker Robert Jan, Klimek Markus
Department of Anesthesiology, Erasmus University Medical Center, Dr. Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands.
Perioper Med (Lond). 2021 Jun 8;10(1):15. doi: 10.1186/s13741-021-00186-4.
The superiority of either the traditional or Stewart based approach to acid-base balance has focused primarily on analyzing metabolic acidemia, with little attention given to patients with neutral pH. In this study, we evaluate metabolic disturbances in patients in the immediate postoperative period focusing on patients with neutral pH, while comparing the Stewart and traditional approach.
We conducted a single center retrospective observational cohort study. Over a 17-month period, data on arterial blood gas analysis, electrolytes, and albumin on the morning after surgery were retrieved from patients admitted to the postsurgical high dependency unit (HDU). Albumin-corrected anion gap (AG), apparent (SIDa) and effective strong ion difference (SIDe), and strong ion gap (SIG) were calculated.
Out of 1207 HDU admissions, 400 cases had a complete set of laboratory-data including albumin of which 281 presented with neutral pH (7.35 ≤ pH ≤ 7.45), 64 with acidemia (pH < 7.35) and 55 with alkalemia (pH > 7.45). In pH neutral patients, the following acidifying disturbances were found: SIDa was lowered in 101 (36%), and SIG was raised in 60 (21%). Base excess (BE) was decreased in 16 (6%) and corrected AG raised in 107 (38%). The alkalizing effect of hypoalbuminemia was present in 137 (49%). Out of 134 cases with normal BE and corrected AG, SIDa was lowered in 58 (43%). Out of 136 cases with normal SIDa and SIG, none had lowered BE and 28 increased AG (21%). Length of stay was significantly longer in patients with hypoalbuminemia, lowered SIDa, and increased corrected AG, but not decreased BE (hypoalbuminemia: 16 days vs. 10 days, P < 0.001; low SIDa: 15 days vs. 12 days, P = 0.015; increased AG: 16 days vs. 11 days, P < 0.001; low BE: 14 days vs. 13 days, P = 0.736).
Metabolic disturbances, characterized mainly by the presence of lowered SIDa, increased AG, and hypoalbuminemia, are frequent in our population with apparent neutral acid-base balance based on pH and base excess. These changes on the morning after surgery are associated with increased length of stay.
传统方法与基于斯图尔特法的酸碱平衡分析方法的优势主要集中在对代谢性酸血症的分析上，而对pH值正常的患者关注较少。在本研究中，我们评估术后即刻患者的代谢紊乱情况，重点关注pH值正常的患者，同时比较斯图尔特法和传统方法。
我们进行了一项单中心回顾性观察队列研究。在17个月的时间里，从入住术后高依赖病房（HDU）的患者中获取术后次日早晨的动脉血气分析、电解质和白蛋白数据。计算白蛋白校正阴离子间隙（AG）、表观强离子差（SIDa）、有效强离子差（SIDe）和强离子间隙（SIG）。
在1207例入住HDU的患者中，400例有完整的实验室数据，包括白蛋白，其中281例pH值正常（7.35≤pH≤7.45），64例为酸血症（pH<7.35），55例为碱血症（pH>7.45）。在pH值正常的患者中，发现以下酸化紊乱情况：101例（36%）SIDa降低，60例（21%）SIG升高。16例（6%）碱剩余（BE）降低，107例（38%）校正AG升高。137例（49%）存在低白蛋白血症的碱化作用。在134例BE和校正AG正常的病例中，58例（43%）SIDa降低。在136例SIDa和SIG正常的病例中，无BE降低者，28例AG升高（21%）。低白蛋白血症、SIDa降低和校正AG升高的患者住院时间明显延长，但BE降低者除外（低白蛋白血症：16天对10天，P<0.001；低SIDa：15天对12天，P = 0.015；AG升高：16天对11天，P<0.001；低BE：14天对13天，P = 0.736）。
在我们基于pH值和碱剩余看似酸碱平衡正常的人群中，以SIDa降低、AG升高和低白蛋白血症为主要特征的代谢紊乱很常见。术后次日的这些变化与住院时间延长有关。
