Instructions
You are a medical student on placement in the emergency department. Stavroula Charalambous, 58, has been brought in by her husband after three days of vomiting and diarrhoea; over the last two days she has become confused and shaky. Her medicines, the triage handover, her bloods and her ECG are below.
Interpret the blood results and ECG provided
Outline to the examiner:
- Your most likely diagnosis and differentials
- Next steps in management, including relevant investigations
- You do not need to take a history or examine the patient
- You may ask the examiner about her current condition
Medicines (Webster pack, checked with her husband)
Lithium carbonate slow-release 450 mg twice daily (15 years) Perindopril 5 mg daily (4 years) Ibuprofen 400 mg three times daily, bought at the pharmacy 10 days ago for a sore right knee Paracetamol 1 g up to four times a day if needed Last lithium dose 8.30 pm yesterday
Triage handover
Bipolar disorder, well for years; high blood pressure. Grandchildren had a stomach bug; vomiting 4 to 5 times a day with watery diarrhoea for 3 days, keeping down only sips. Muddled for 2 days, hands shaking far more than her usual fine tremor; slurred speech and unsteady since this morning.
From her husband
She kept taking her tablets until this morning, when she was too muddled to take her lithium. He fills her Webster pack and no extra tablets are missing. No recent low mood or talk of self-harm. No fever, headache, fall or head injury. No alcohol. No known allergies.
Blood tests for Stavroula Charalambous, 9.30 am
Lithium 2.6 mmol/L (range 0.4 to 1.0; 0.7 three months ago), 13 hours after her last dose. Creatinine 190 umol/L (range 45 to 90; 85 three months ago). eGFR 26 mL/min/1.73m2 (68 three months ago). Urea 15.6 mmol/L (range 3.0 to 8.0).
Other bloods, 9.30 am
Sodium 132 mmol/L (135 to 145); potassium 3.4 mmol/L (3.5 to 5.2); chloride 98 mmol/L (95 to 110); bicarbonate 21 mmol/L (22 to 32). Glucose 6.0 mmol/L; corrected calcium 2.36 mmol/L; haemoglobin 146 g/L; white cells 9.4 x10^9/L; CRP 8 mg/L (under 5).
12-lead ECG, 9.20 am
Regular sinus rhythm at 92/min, a P wave before every QRS, PR 180 ms, QRS 90 ms, axis +30 degrees. Flattened T waves in II, aVF and V4 to V6; no U waves. QTc 470 ms (under 460).
Blood tests for Stavroula Charalambous, 58, taken in the emergency department at 9.30 am
| Item | Value | Reference range |
|---|---|---|
| Sodium | 132 mmol/L | 135-145 mmol/L |
| Potassium | 3.4 mmol/L | 3.5-5.2 mmol/L |
| Chloride | 98 mmol/L | 95-110 mmol/L |
| Bicarbonate | 21 mmol/L | 22-32 mmol/L |
| Urea | 15.6 mmol/L | 3.0-8.0 mmol/L |
| Creatinine | 190 umol/L (85 umol/L three months ago) | 45-90 umol/L |
| eGFR | 26 mL/min/1.73m2 (68 three months ago) | >90 mL/min/1.73m2 |
| Corrected calcium | 2.36 mmol/L | 2.10-2.60 mmol/L |
| Glucose (random) | 6.0 mmol/L | 3.0-7.8 mmol/L |
| Lithium (13 hours after the last dose) | 2.6 mmol/L (0.7 mmol/L three months ago) | 0.4-1.0 mmol/L |
| Haemoglobin | 146 g/L | 115-160 g/L |
| White cell count | 9.4 x10^9/L | 4.0-11.0 x10^9/L |
| CRP | 8 mg/L | <5 mg/L |
12-lead ECG for Stavroula Charalambous, 58, at 9.20 am
| Item | Value | Reference range |
|---|---|---|
| Rate | 92 /min | 60-100 /min |
| Rhythm | Regular, a P wave before every QRS | Regular sinus rhythm |
| Axis | +30 degrees | -30 to +90 degrees |
| P waves | Normal shape and size | Upright before every QRS |
| PR interval | 180 ms | 120-200 ms |
| QRS duration and morphology | 90 ms, narrow, normal shape | Narrow, under 120 ms |
| ST segments | On the baseline in all leads | Isoelectric |
| T waves | Low and flat in II, aVF and V4 to V6; no U waves | Upright in I, II and V3-V6 |
| QTc | 470 ms | <460 ms |