Instructions
You are a medical student on placement in the sleep medicine clinic. Hoa Dinh, 54, a school canteen worker from Kalgoorlie, has been referred by her GP with loud snoring, morning headaches and swollen ankles. Her GP letter and results are printed for you.
Interpret the results provided
Outline to the examiner:
- Your findings
- 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 do not need to explain the results to the patient
- Vital signs are given on request
GP letter: sleep
Loud snoring for years; her husband says she stops breathing and gasps in her sleep. Wakes unrefreshed with a headache most mornings. Epworth score 17 out of 24. No previous sleep study.
GP letter: daytime
Dozes off in front of the TV; has twice nodded off at traffic lights driving to work. Ankles swollen for 6 months; puffed walking up the slope to the canteen.
GP letter: background
Raised blood pressure for 8 years. Never smoked. A glass or two of wine most evenings.
GP letter: medicines
Amlodipine 10 mg and perindopril 10 mg daily (the GP wonders if the amlodipine is causing the swelling). Temazepam 10 mg at night for 2 months, for poor sleep. No known allergies.
Arterial blood gas (room air, awake, seated at rest)
| Item | Value | Reference range |
|---|---|---|
| pH | 7.37 | 7.35-7.45 |
| pCO2 | 56 mmHg | 35-45 mmHg |
| pO2 | 58 mmHg | 80-100 mmHg |
| HCO3 | 32 mmol/L | 22-26 mmol/L |
| Base excess | +6 mmol/L | -2 to 2 mmol/L |
| Lactate | 0.9 mmol/L | 0.5-2.0 mmol/L |
| Na | 139 mmol/L | 135-145 mmol/L |
| K | 4.2 mmol/L | 3.5-5.2 mmol/L |
| Glucose | 6.4 mmol/L | 3.0-7.8 mmol/L |
Taken at 10 am in the clinic, breathing room air (FiO2 0.21), awake and seated at rest.
Bloods
| Item | Value | Reference range |
|---|---|---|
| Haemoglobin | 172 g/L | 115-165 g/L |
| Haematocrit | 0.52 | 0.35-0.47 |
| White cells | 7.4 x10^9/L | 4.0-11.0 x10^9/L |
| Platelets | 248 x10^9/L | 150-400 x10^9/L |
| TSH | 2.1 mIU/L | 0.4-4.0 mIU/L |
| Creatinine | 68 umol/L | 45-90 umol/L |
ECG
| Item | Value | Reference range |
|---|---|---|
| Rate | 88 /min | 60-100 /min |
| Rhythm | Sinus rhythm | - |
| Axis | +110 degrees | - |
| P waves | Peaked, 3 mm tall in lead II | - |
| PR interval | 160 ms | 120-200 ms |
| QRS duration and morphology | 92 ms; R:S ratio above 1 in V1; deep S waves in V5 and V6 | - |
| ST segments | Isoelectric | - |
| T waves | Inverted in V1 to V3 | - |
| QTc | 438 ms | <460 ms |
Echocardiogram
| Item | Value | Reference range |
|---|---|---|
| Image quality | Limited windows due to body habitus | - |
| Left ventricle | Normal size and wall thickness; LVEF 60% | - |
| Right ventricle | Mildly dilated; TAPSE 16 mm | >=17 mm |
| Right atrium | Mildly dilated | - |
| Tricuspid regurgitant velocity | 3.0 m/s | <2.8 m/s |
| Estimated RV systolic pressure | 51 mmHg | <35 mmHg |
| Inferior vena cava | 23 mm; collapses less than 50% on sniff | - |
| Valves and pericardium | Mild tricuspid regurgitation; other valves normal; no effusion | - |
Spirometry
| Item | Value | Reference range |
|---|---|---|
| FEV1 | 76% predicted (2.02 L) | 80-120% |
| FVC | 74% predicted (2.43 L) | 80-120% |
| FEV1/FVC | 0.83 | >0.70 |
| Post-bronchodilator change | FEV1 +3% (60 mL) | <12% and 200 mL |