Periodic paralysis: An unusual presentation of drug-induced hyperkalemia
A 67-year-old woman presented to emergency department with complaints of episodes of inability to walk for the past 5 days, happening 4-5 times a day. Each episode lasted for 15-20 minutes and was associated with restlessness and breathlessness. Patient was apparently alright one month before, since then she started feeling generalized weakness on and off. However, for past 5 days symptoms were exaggerated and she started feeling sudden loss of power in both the lower limbs simultaneously and inability to walk. She could walk normally after the episode subsided. This episode was not associated with pain in the limbs. Patient was totally conscious during the entire episode. Her medical history was significant for diabetes and hypertension for the past 5 years. The patient's drug therapy consisted of insulin nova mixtard 30/70 (for the past 10 years), olmesartan 20 mg per day (for past 2 years), perindopril 4 mg per day (for past 16 months), and torsemide 10 mg per day (for past 6 months).\nOn examination she was found to be alert and fully oriented. Vital signs revealed a regular pulse rate of 93 beats per minute, blood pressure of 130/80 mmHg, temperature of 36.8°C, a respiratory rate of 14/min and oxygen saturation of 100% on room air by pulse oxymetry. Cardiac auscultation revealed normal heart sounds, respiratory examination revealed bilateral vesicular breath sounds with bilateral basal crepitations. Complete neurological examination did not reveal significant finding.\nThe results of laboratory examination were as follows: 10.6 g%, Total Leukocyte Count: 10,500, Differential Leukocyte Count: N70 L26 M3 E1 B0, ESR: 12 mm/hr, Random blood sugar: 98 mg/dl, Urea: 24 mg/dl, Creatinine: 1.2 mg/dl, Total Cholesterol: 198 mg/dl, Triglyceride: 112 mg/dl, HDL: 38 mg/dl, LDL: 138 mg/dl, Serum sodium: 134 mEq/L, Serum potassium: 8.6 mEq/L, Total calcium: 11 mg/dl, Ionized calcium: 1.30 mEq/L, Serum Magnesium: 2.5 mg/dl, Serum chloride: 104 mmol/L, Serum Bicarbonate: 24 mmol/l. ECG showed normal sinus rhythm, normal axis, and tall T waves. CT scan and EMG were not done.\nDiabetic neuropathy, Gullian Barre Syndrome, metabolic cause of periodic paralysis.\nThe diagnosis of drug-induced hyperkalemia presenting as periodic paralysis was suggested by very high serum potassium concentration during the attack and also persistent hyperkalemia between attacks.\nPatient was immediately admitted and the treatment for hyperkalemia was instituted. Drugs causing potassium retention were immediately stopped. Medical measures were started to lower down the level of serum K+ which included K+ bind sachet (calcium polystyrene sulfonate) thrice daily. Lactulose syrup and magnesium sulfate was given to avoid constipation. Her K+ started decreasing progressively and within 24 h K+ got reduced from 8.4 mEq/L to 6.8 mEq/L. In the next 24 h serum K+ further lowered from 6.8 to 5.4 mEq/L.\nThere was progressive fall of blood pressure during the course of the treatment and patient was overall drowsy and disoriented. Measures were taken to maintain her blood pressure.\nPatient responded well to the treatment and was discharged in a stable state with serum K+ level of 5.1 mEq/L, and blood pressure of 120/80 mmHg on 5th day of admission.\nThe patient has been followed-up on an outpatient basis, her serum potassium has been stable with no further episodes of periodic paralysis.