Refractory hypokalaemia in an elderly patientBMJ 2017; 357 doi: https://doi.org/10.1136/bmj.j1575 (Published 12 April 2017) Cite this as: BMJ 2017;357:j1575
- Subramaniam Nagasayi, consultant in geriatric medicine1,
- Sandra Hui Li Yan, year 3 internal medicine medical officer1,
- Cleo Chiong, year 5, medical student2
- 1Department of Geriatric Medicine, Changi General Hospital, Singapore
- 2NUS Yong Loo Lin School of Medicine, Singapore
- Correspondence to N Subramaniam
A 94 year old woman with mild dementia, peripheral vascular disease, and type 2 diabetes mellitus was discharged from hospital after completing antiviral treatment for a lower respiratory tract infection (influenza A3). She was readmitted four days later with secondary pneumonia and bacteraemia (meticillin sensitive Staphylococcus aureus, isolated from blood but not from lung or sputum samples). She was started on intravenous cloxacillin (2 g, every six hours) according to local guidelines. She had no episodes of diarrhoea, vomiting, respiratory muscle weakness, or paralytic ileus. On admission, her temperature was 38°C, blood pressure 141/70 mm Hg, respiratory rate 24 breaths/min, heart rate 114 beats/min, and peripheral capillary oxygen saturation 94%. Chest examination found normal heart sounds and right basal crepitations. Her abdomen was soft and non-tender; and her weight was 43 kg (body mass index 16 kg/m2).
By day five, her respiratory parameters had improved, but she had developed extreme fatigue with refractory hypokalaemia, despite oral and parenteral replacements (table 1⇓).
She continued on regular 100 mg aspirin and 20 mg omeprazole once daily and 250 mg tolbutamide twice daily. She was started on 600 mg slow release potassium chloride twice daily in addition to intravenous replacement.
Her haemoglobin level was 134 …