1. www.cmft.nhs.uk/undergrad OSCE Data interpretation stations Dr Cathy Armstrong Consultant Anaesthetist Dec 2014

2. www.cmft.nhs.uk/undergrad Objectives The stations – Format – Tips Blood tests – Patterns to look for examples

3. www.cmft.nhs.uk/undergrad Format Instructions – Brief background – Study data – ‘after 5 minutes the examiner will ask you some questions on diagnosis & initial management’

4. www.cmft.nhs.uk/undergrad Format Data – Blood tests – ECG – CXR – Observations

5. www.cmft.nhs.uk/undergrad Format Questions from examiner – Structured / standardised ‘what do the blood tests show?’ ‘what does the CXR show?’ What is your most likely diagnosis? What is your top differential? What will your initial management be?

6. www.cmft.nhs.uk/undergrad Tips Use your thinking time wisely Use succinct language & be confident – Likely to be some normal investigations also Show reasoning behind your thoughts Flag up potential dangers

7. www.cmft.nhs.uk/undergrad Tips Differential diagnosis – Start with your top & why Initial management – Might include oxygen / fluids / nebulisers – Remember management packages – e.g septic 6 – Further detailed history – Other definitive investigations – e.g.echo, CT – Don’t forget SENIOR HELP / INPUT

8. www.cmft.nhs.uk/undergrad Investigations

9. www.cmft.nhs.uk/undergrad Full Blood Count Hb – Males 135 – 180g/l – Females 115 – 160 g/l WCC – 4.0 – 11 x 10 9 /l Platelets – 150 – 400 x 10 9 /l

10. www.cmft.nhs.uk/undergrad Anaemia classification by MCV MCV – mean cell volume (76 – 96 fl) Normal MCV (Normocytic) – Acute blood loss – Anaemia of chronic disease Low MCV (microcytic) – Iron deficiency – Thalassaemia High MCV (Macrocytic) – B12 or folate deficiency

11. www.cmft.nhs.uk/undergrad High wcc - neutrophilia Raised WCC most commonly due to neutrophilia Neutrophils account for 40 – 75% of WBC recognise & ingest foreign particles & microorganisms Causes of neutrophilia – Infection – Trauma – Infarction – Inflammation – Malignancy – Myeloproliferative disease – Physiological (exercise & pregnancy)

12. www.cmft.nhs.uk/undergrad Low wcc - neutropenia  Most commonly caused by neutropenia  Causes of neutropenia  Infection  Drugs  Autoimmune  Alcohol  congenital

13. www.cmft.nhs.uk/undergrad Thrombocytosis Reactive – Chronic inflammatory disorders – Malignant disease – Post-haemorrhage – Post-splenectomy – Haemolytic anaemias Malignant – Essential thrombocythaemia – Polycythaemia rubra vera – myelofibrosis

14. www.cmft.nhs.uk/undergrad Thrombocytopenia Marrow disorders – Hypoplasia – idiopathic, drug-induced – Infiltration Leukaemia, Myeloma, Carcinoma, Myelofibrosis – B12 / folated deficiency Increased consumption of platelets – DIC, ITP, viral infections, bacterial infections Hypersplenism – Lymphoma, liver disease

15. www.cmft.nhs.uk/undergrad Urea & electrolytes Na 135-145 mmol/l K 3.5 – 5.5 mmol/l Ur 2.5 – 6.7 mmol/l Cr 70 – 150 mmol/l

16. www.cmft.nhs.uk/undergrad Hyperkalaemia Mild 5.5 - 6.0 mmol/l Mod6.1 – 7.0 mmol/l Severe > 7.0 mmol/l Causes – ↑ intake Food ingestion / supplements Rapid blood transfusion – Intercompartmental shifts Trauma / crush injuries Burns Acidosis – Decreased excretion Acute / chronic renal failure Adrenocortical insufficiency (e.g. Addisons disease) – Medications Potassium sparing diuretics, digoxin

17. www.cmft.nhs.uk/undergrad Hyperkalaemia  ECG changes  Peaked T waves  Prolonged PR interval  Widened QRS  Loss of P wave  Loss of R wave amplitude  Sine wave pattern  Asystole  Management of mod / severe  Treat underlying cause  Calcium gluconate  Insulin dextrose infusion  Nebulised salbutamol  dialysis

18. www.cmft.nhs.uk/undergrad Hypokalaemia Mild 3.0 – 3.5 mmol/l Mod2.5 – 3.0 mmol/l Severe < 2.5 mmol/l Causes – ↓ intake Iatrogenic (no K in IV fluids) Malnutrition – Renal losses Renal tubular acidosis Hyperaldosteronism (Conn’s syndrome) – GI losses Diarrhoea, vomiting – Intercompartmental shifts insulin Alkalosis – Medications Diuretics, β2 agonists

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20. Hypernatraemia Usually due to water loss in excess of sodium loss Causes include: – Iatrogenic (too much IV N saline) – Diabetes Insipidus – Primary aldosteronism (Conn’s Syndrome)

21. www.cmft.nhs.uk/undergrad Diseases with electrolyte patterns Addisons disease (Primary adrenocortical insufficiency) – NaKCa Cushings syndrome (excess plasma cortisol) – NaKCa Conn’s Syndrome (hyperaldosteronism) – NaK

22. www.cmft.nhs.uk/undergrad Diseases with electrolyte patterns Addisons disease (Primary adrenocortical insufficiency) – Na ↓K ↑Ca ↑ Cushings syndrome (excess plasma cortisol) – Na ↑ K ↓ Ca ↓ Conn’s Syndrome (hyperaldosteronism) – Na ↑ ↔K ↓

23. www.cmft.nhs.uk/undergrad Raised Urea & creatinine Both raised in renal failure Alternative causes of a raised urea with relatively normal Cr – Dehydration – GI haemhorrhage – High protein diet

24. www.cmft.nhs.uk/undergrad Deciphering between acute & chronic renal failure using blood results  Chronic renal failure  Anaemia of chronic disease  Low calcium  High phosphate

25. www.cmft.nhs.uk/undergrad Liver Function tests Non-specific Bilirubin AST (Aspartate transaminase) ALP (Alkaline phophatase) γ – GT (Gamma –glutamyl transpeptidase) Albumin Specific ALT (Alanine aminotransferase)

26. www.cmft.nhs.uk/undergrad LFT patterns Hepatocellular Damage – Large ↑ in ALT with small ↑ in ALP Biliary obstruction – Small ↑ ALT with large ↑ in ALP & γ -GT

27. www.cmft.nhs.uk/undergrad Areas not covered Clotting studies – Anticoagulant monitoring CRP Blood cultures Specialist tests – E.g – vasculitis screens / immunology

28. www.cmft.nhs.uk/undergrad Normal ABG Values pH PaO 2 PaCO 2 HCO 3 Base Excess 7.35 - 7.45 10-12 kPa 4.5 - 6.0 kPa 22 – 26 mmol/l -2 - +2 mmol/l Many modern gas machines also measure K + Na + Cl - SaO 2 Hb COHb MetHb Lactate IN AIR

29. www.cmft.nhs.uk/undergrad Expected PO 2 on oxygen % oxygen – 10

30. www.cmft.nhs.uk/undergrad Examples

31. www.cmft.nhs.uk/undergrad Ryan Ryan is a 17 year old male. He has presented to A&E with a 2 month history of general malaise. Over the past few days he has been vomiting with stomach cramps. BP 110/70, Apyrexial, RR 39 Review the investigations provided. You will then be asked questions on diagnosis and initial management.

32. www.cmft.nhs.uk/undergrad Ryan

33. www.cmft.nhs.uk/undergrad Ryan Hb 12.9 (9.0 – 13.0) Wcc 7.0 (4.0 – 11.0) Plt 395 (150-400) Na 139 (135-145) K 4.5 (3.5-5.5) Ur 15.0 (3.3-6.6) Cr 140 (80-120) Blood glucose 35mmol/l ABG on air pH 7.12 (7.35-7.45) PCo2 3.0 (4.5-6.0) PO2 11.0 (10-12 in air) HCO3 17 (22-26) BE -23 (-2- +2)

34. www.cmft.nhs.uk/undergrad Ryan

35. www.cmft.nhs.uk/undergrad Jack Jack is a 77 year old male. He has presented to A&E with a 2 day history of abdominal pain and vomiting. BP 90/45, T 38.5. RR 30 Examination of the abdomen reveals a hard abdomen with generalised tenderness and guarding Review the investigations provided. You will then be asked questions on diagnosis and initial management.

36. www.cmft.nhs.uk/undergrad Jack Hb 9.0 (9.0 – 13.0) Wcc 22.3 (4.0 – 11.0) Plt 170 (150-400) Na 139 (135-145) K 4.5 (3.5-5.5) Ur 10.0 (3.3-6.6) Cr 130 (80-120) ABG on air pH 7.22 (7.35-7.45) PCo2 6.1 (4.5-6.0) PO2 7.5 (10-12 in air) HCO3 18 (22-26) BE -10 (-2- +2)

37. www.cmft.nhs.uk/undergrad Jack

38. www.cmft.nhs.uk/undergrad Jack

39. www.cmft.nhs.uk/undergrad Dorothy Dorothy is a 82 year old female. She has presented to A&E with a 5 day history of productive cough with green sputum and worsening shortness of breath. BP 93/50, T 38.5. RR 32 Review the investigations provided. You will then be asked questions on diagnosis and initial management.

40. www.cmft.nhs.uk/undergrad Dorothy Hb 11.0 (9.0 – 13.0) Wcc 21.0 (4.0 – 11.0) Plt 250 (150-400) Na 139 (135-145) K 4.5 (3.5-5.5) Ur 8.0 (3.3-6.6) Cr 90 (80-120) ABG on 60% oxygen pH 7.35 (7.35-7.45) PCo2 4.2 (4.5-6.0) PO2 13 (10-12 in air) HCO3 23 (22-26) BE -3 (-2- +2)

41. www.cmft.nhs.uk/undergrad Dorothy

42. www.cmft.nhs.uk/undergrad Dorothy

43. www.cmft.nhs.uk/undergrad CURB 65 Confusion Urea – 7.0 or over RR 30 or over BP – Systolic 90 or less OR – Diastolic 60 or less Age 65 or over

44. www.cmft.nhs.uk/undergrad Sepsis 6 Oxygen Blood cultures IV antibiotics Lactate & FBC IV fluids Measure UO

45. www.cmft.nhs.uk/undergrad Tom Tom is a 22 year old male. He has presented to A&E with shortness of breath and an audible wheeze BP 135/90, T 36.5. RR 38 Review the investigations provided. You will then be asked questions on diagnosis and initial management.

46. www.cmft.nhs.uk/undergrad Tom Hb 11.0 (9.0 – 13.0) Wcc 6.0 (4.0 – 11.0) Plt 250 (150-400) Na 139 (135-145) K 4.5 (3.5-5.5) Ur 5.9 (3.3-6.6) Cr 80 (80-120) ABG on 15L oxygen via non-rebreath mask pH 7.32 (7.35-7.45) PCo2 5.9 (4.5-6.0) PO2 9 (10-12 in air) HCO3 23 (22-26) BE -3 (-2- +2)

47. www.cmft.nhs.uk/undergrad Tom

48. www.cmft.nhs.uk/undergrad Tom

49. www.cmft.nhs.uk/undergrad summary  Read instructions carefully  Take time to look at data, formulate a differential diagnosis & initial management plan  Be confident in your approach  Remember senior input

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