Molnar Amber O, Killin Lauren, Bota Sarah, McArthur Eric, Dixon Stephanie N, Garg Amit X, Harris Claire, Thompson Stephanie, Tennankore Karthik, Blake Peter G, Bohm Clara, MacRae Jennifer, Silver Samuel A
Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON, Canada.
Institute for Clinical Evaluative Sciences, London, ON, Canada.
Can J Kidney Health Dis. 2024 May 30;11:20543581241256774. doi: 10.1177/20543581241256774. eCollection 2024.
It is unclear whether the use of higher dialysate bicarbonate concentrations is associated with clinically relevant changes in the pre-dialysis serum bicarbonate concentration.
The objective is to examine the association between the dialysate bicarbonate prescription and the pre-dialysis serum bicarbonate concentration.
This is a retrospective cohort study.
The study was performed using linked administrative health care databases in Ontario, Canada.
Prevalent adults receiving maintenance in-center hemodialysis as of April 1, 2020 (n = 5414) were included.
Patients were grouped into the following dialysate bicarbonate categories at the dialysis center-level: individualized (adjustment based on pre-dialysis serum bicarbonate concentration) or standardized (>90% of patients received the same dialysate bicarbonate concentration). The standardized category was stratified by concentration: 35, 36 to 37, and ≥38 mmol/L. The primary outcome was the mean outpatient pre-dialysis serum bicarbonate concentration at the patient level.
We examined the association between dialysate bicarbonate category and pre-dialysis serum bicarbonate using an adjusted linear mixed model.
All dialysate bicarbonate categories had a mean pre-dialysis serum bicarbonate concentration within the normal range. In the individualized category, 91% achieved a pre-dialysis serum bicarbonate ≥22 mmol/L, compared to 87% in the standardized category. Patients in the standardized category tended to have a serum bicarbonate that was 0.25 (95% confidence interval [CI] = -0.93, 0.43) mmol/L lower than patients in the individualized category. Relative to patients in the 35 mmol/L category, patients in the 36 to 37 and ≥38 mmol/L categories tended to have a serum bicarbonate that was 0.70 (95% CI = -0.30, 1.70) mmol/L and 0.87 (95% CI = 0.14, 1.60) mmol/L higher, respectively. There was no effect modification by age, sex, or history of chronic lung disease.
We could not directly confirm that all laboratory measurements were pre-dialysis. Data on prescribed dialysate bicarbonate concentrations for individual dialysis sessions were not available, which may have led to some misclassification, and adherence to a practice of individualization could not be measured. Residual confounding is possible.
We found no significant difference in the pre-dialysis serum bicarbonate concentration irrespective of whether an individualized or standardized dialysate bicarbonate was used. Dialysate bicarbonate concentrations ≥38 mmol/L (vs 35 mmol/L) may increase the pre-dialysis serum bicarbonate concentration by 0.9 mmol/L.
尚不清楚使用较高的透析液碳酸氢盐浓度是否与透析前血清碳酸氢盐浓度的临床相关变化有关。
研究透析液碳酸氢盐处方与透析前血清碳酸氢盐浓度之间的关联。
这是一项回顾性队列研究。
该研究使用了加拿大安大略省的关联行政医疗保健数据库。
纳入截至2020年4月1日接受维持性中心血液透析的成年患者（n = 5414）。
在透析中心层面，将患者分为以下透析液碳酸氢盐类别：个体化（根据透析前血清碳酸氢盐浓度进行调整）或标准化（>90%的患者接受相同的透析液碳酸氢盐浓度）。标准化类别按浓度分层：35、36至37以及≥38 mmol/L。主要结局是患者层面的门诊透析前血清碳酸氢盐浓度均值。
我们使用调整后的线性混合模型研究透析液碳酸氢盐类别与透析前血清碳酸氢盐之间的关联。
所有透析液碳酸氢盐类别透析前血清碳酸氢盐浓度均值均在正常范围内。在个体化类别中，91%的患者透析前血清碳酸氢盐≥22 mmol/L，而标准化类别中这一比例为87%。标准化类别患者的血清碳酸氢盐往往比个体化类别患者低0.25（95%置信区间[CI] = -0.93, 0.43）mmol/L。相对于35 mmol/L类别的患者，36至37 mmol/L和≥38 mmol/L类别的患者血清碳酸氢盐往往分别高0.70（95% CI = -0.30, 1.70）mmol/L和0.87（95% CI = 0.14, 1.60）mmol/L。年龄、性别或慢性肺病病史未产生效应修饰作用。
我们无法直接确认所有实验室测量均为透析前测量。无法获取各个透析疗程规定的透析液碳酸氢盐浓度数据，这可能导致一些错误分类，并且无法衡量对个体化做法的依从性。可能存在残余混杂因素。
我们发现，无论使用个体化还是标准化的透析液碳酸氢盐，透析前血清碳酸氢盐浓度均无显著差异。透析液碳酸氢盐浓度≥38 mmol/L（对比35 mmol/L）可能使透析前血清碳酸氢盐浓度升高0.9 mmol/L。
