Ehren Kathrin, Marx A, Wasmuth J-C
Medizinische Klinik 1, Universitätsklinikum Bonn, Bonn.
Dtsch Med Wochenschr. 2010 Oct;135(41):2021-3. doi: 10.1055/s-0030-1267476. Epub 2010 Oct 5.
The 27 year old female patient presented with chronic hypokalaemia known for 6 years and current potassium values of 1.8 mmol/l. She reported having diarrhea for a few days, fever was denied.
Physical examination revealed dry skin and mucosa and a slim nutritional status, laboratory investigations showed a hypokalaemic, hypochloraemic alkalosis and hypomagnesaemia. Our first suspicion was an eating disorder or abuse of diuretics or laxatives. Urine analysis showed a high concentration of potassium and chloride, a screening for diuretics was negative. Due to the electrolyte constellation we assumed a Gitelman's Syndrome which was confirmed by genetic testing.
After intravenous substitution of potassium and cessation of diarrhea the potassium values stabilised at 2.5 - 3.0 mmol/l. After being discharged she continued oral substitution of potassium and no such period of severe hypokalaemia occurred again.
Establishing a diagnosis for patients with chronic hypokalaemia may present difficulties. Urine analysis can help to find reasons for electrolyte disorders. Via measurement of urinary chloride concentration repetitious vomiting as stigmatising diagnosis could be excluded. Urine analysis also led to the diagnosis Gitelman syndrome, an inherited renal tubular disorder, which is suspected to count for 50 % of unexplained chronic hypokalemia.
该27岁女性患者有6年慢性低钾血症病史，当前血钾值为1.8mmol/L。她自述腹泻数日，否认发热。
体格检查发现皮肤和黏膜干燥，营养状况消瘦，实验室检查显示低钾性、低氯性碱中毒和低镁血症。我们首先怀疑是饮食失调或滥用利尿剂或泻药。尿液分析显示钾和氯浓度高，利尿剂筛查为阴性。鉴于电解质情况，我们推测为吉特林综合征，基因检测证实了这一诊断。
静脉补钾及腹泻停止后，血钾值稳定在2.5 - 3.0mmol/L。出院后她继续口服补钾，未再出现如此严重的低钾血症时期。
为慢性低钾血症患者确诊可能存在困难。尿液分析有助于找出电解质紊乱的原因。通过测量尿氯浓度可排除作为鉴别诊断的反复呕吐。尿液分析还得出了吉特林综合征的诊断，这是一种遗传性肾小管疾病，据推测占不明原因慢性低钾血症的50%。
