Mohapatra Biranchi Narayan, Lenka Sujit Kumar, Acharya Manoranjan, Majhi Chakradhar, Oram Gouri, Tudu Khetra Mohan
Professor.
Junior Resident.
J Assoc Physicians India. 2016 May;64(5):52-58.
To study the clinical profile of hypokalemic flaccid paralysis (HKFP) and to evaluate its causes.
Fifty cases of hypokalemic flaccid paralysis (HKFP) admitted between November 2012 to October 2014 were taken up in the study. Serum potassium level < 3.5 mmol/ltr has been taken as hypokalemia. All cases were studied for spot and/or 24 hour urinary sodium / potassium, serum potassium / calcium / magnesium. Hypokalemic periodic paralysis (HPP) were diagnosed if there was spot/24 hour urine potassium excretion < 20mmol/ltr in presence of hypokalemia and flaccid weakness without other causes. EMG and nerve conduction study were done to exclude polyneuropathy and myopathic cases.
Out of 50 cases of HKFP, male gender predominated (88%). Maximum number of cases (70%) occurred in 21 to 40 years of age. It occurred in all seasons but more in summer (58%). The precipitating factors were present in 76% of cases out of which high carbohydrate meal (28%), vomiting (16%), excessive sweating (8%), diarrhea (8%) and increased urination (12%) were present. Twenty percent of cases had recurrence (2 to 3 episodes most often) and 6% of cases had family history. Quadriparesis was seen in (54%), paraparesis (36%), hemiparesis (10%) and neck muscle weakness (32%). No case was present with respiratory paralysis or cranial nerve palsy. Twenty-one cases (42%) have very low potassium < 2.5 mmol/ltr, 11 cases (22%) with potassium level between 2.5 to 2.9 mmol/ltr and 18 cases (36%) with 3 to 3.5 mmol/ltr. There was no correlation between severity weakness and potassium level. Eleven cases (22%) had thyrotoxicosis and 3 cases (6%) were hypothyroid. Thirteen cases (26%) have excess urinary loss of potassium (≥20 mmol/ltr) of which 5 cases (10%) were distal renal tubular acidosis (dRTA), four cases (8%) were Gitelman's syndrome (GS) and in 4 cases exact cause could not be diagnosed. Non-renal / prior renal loss of potassium like diarrhea and excessive sweating was responsible in 8% cases each and vomiting in 10% of cases. One unique case of hypernatraemic hypokalemic paralysis (HHP) was found. Only 9 (18%) cases are hypokalemic periodic paralysis (HPP).
HKFP is a hetergenous group of disease of which a significant number of patients had thyroid disorders mostly in the form of thyrotoxicosis followed by renal tubular dysfunctions like dRTA and GS; non-renal and prior renal loss of potassium like diarrhea, excessive sweating and vomiting respectively. Early recognition and prompt management of these conditions will give gratifying result and prevent further attacks in some cases.
研究低钾性软瘫（HKFP）的临床特征并评估其病因。
本研究纳入了2012年11月至2014年10月期间收治的50例低钾性软瘫患者。血清钾水平<3.5 mmol/l被视为低钾血症。对所有病例进行即时和/或24小时尿钠/钾、血清钾/钙/镁的检测。如果在低钾血症和软瘫无力且无其他病因的情况下，即时/24小时尿钾排泄<20mmol/l，则诊断为低钾性周期性麻痹（HPP）。进行肌电图和神经传导研究以排除多发性神经病和肌病病例。
在50例HKFP患者中，男性占主导（88%）。最大病例数（70%）发生在21至40岁年龄段。该病全年均可发生，但夏季更多见（58%）。76%的病例存在诱发因素，其中高碳水化合物餐（28%）、呕吐（16%）、多汗（8%）、腹泻（8%）和多尿（12%）。20%的病例有复发（最常见2至3次发作），6%的病例有家族史。四肢瘫见于（54%）、截瘫（36%）、偏瘫（10%）和颈部肌肉无力（32%）。无呼吸麻痹或颅神经麻痹病例。21例（42%）血钾极低<2.5 mmol/l，11例（22%）血钾水平在2.5至2.9 mmol/l之间，18例（36%）血钾在3至3.5 mmol/l之间。肌无力严重程度与血钾水平之间无相关性。11例（22%）有甲状腺毒症，3例（6%）为甲状腺功能减退。13例（26%）有钾的尿排泄过多（≥20 mmol/l），其中5例（10%）为远端肾小管酸中毒（dRTA），4例（8%）为吉特林综合征（GS），4例确切病因无法诊断。非肾性/既往肾性钾丢失如腹泻和多汗各占8%的病例，呕吐占10%的病例。发现1例独特的高钠血症性低钾性麻痹（HHP）病例。仅9例（18%）为低钾性周期性麻痹（HPP）。
HKFP是一组异质性疾病，其中相当数量的患者患有甲状腺疾病，大多表现为甲状腺毒症，其次是肾小管功能障碍如dRTA和GS；非肾性和既往肾性钾丢失分别如腹泻、多汗和呕吐。对这些情况的早期识别和及时处理将取得满意结果，并在某些情况下预防进一步发作。
