Assadi Farahnak
Department of Pediatrics, Division of Nephrology, Rush University Medical Center, Chicago, Illinois, USA.
Pediatr Pulmonol. 2023 Jun;58(6):1815-1817. doi: 10.1002/ppul.26392. Epub 2023 Mar 23.
Low plasma bicarbonate concentration due to chronic respiratory alkalosis may be misdiagnosed as metabolic acidosis and mistreated with administration of alkali therapy, particularly when arterial blood gas is not available.
We measured urine anion gap [urine (Na + K ) - (Cl )], as a surrogate of renal ammonium excretion in 15 patients presenting with hyperventilation and low serum bicarbonate concentration to distinguish chronic respiratory alkalosis (CRA) from metabolic acidosis (MA) when blood gas was unavailable.
Hyperventilation and low serum bicarbonate concentrations were associated with urine pH above 5.5 and positive urine anion gap in all, suggesting CRA. The diagnosis was later confirmed by obtaining capillary blood gas, which showed a decrease in PCO and high normal pH values.
The use of urine anion gap can help to differentiate between chronic respiratory alkalosis and metabolic acidosis, especially when arterial blood gas is not obtained.
由于慢性呼吸性碱中毒导致的低血浆碳酸氢盐浓度可能被误诊为代谢性酸中毒，并给予碱疗法进行错误治疗，尤其是在无法获得动脉血气分析结果时。
我们测量了15例出现通气过度和低血清碳酸氢盐浓度患者的尿阴离子间隙[尿（钠+钾）-氯]，作为肾脏铵排泄的替代指标，以便在无法进行血气分析时区分慢性呼吸性碱中毒（CRA）和代谢性酸中毒（MA）。
通气过度和低血清碳酸氢盐浓度与所有患者尿pH高于5.5及尿阴离子间隙阳性相关，提示为CRA。随后通过采集毛细血管血气分析确诊，结果显示二氧化碳分压降低且pH值略高于正常。
尿阴离子间隙的应用有助于区分慢性呼吸性碱中毒和代谢性酸中毒，特别是在未获取动脉血气分析结果时。
