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LFTs & U&Es

Easan Anand

Elissa Kaur

What are Liver Function Tests?

Marker Range

ALT 5-35 iU/L

AST 5-35 iU/L

ALP 30-150 iU/L

Y-GT 11-51 u/L (M) 7-33 u/L (F)

Albumin 35-50 g/L

Bilirubin 3-17 umol/L

Interpreting LFTs

HPC Abdo Pain, Jaundice, N+V, Bowel Habits (Diarrhoea, Constipation), Bleeding, Weight Loss, Appetite Change, Fever, Pruritis

Sx Travel Hx, IVDU, Tattoos, Blood Tx

Dx Dx-induced Liver Disease

O/E

Clubbing etc etc, Signs of Chronic Liver Disease: Clubbing, Leukonychia, Palmar Erythema, Asterixis, Excoriations, Jaundice, Spider Naevi, Paucity of Hair Distribution, Gynaecomastia, Ascites, Striae

Common Patterns of LFT abnormality

Most common Differentials

Rarer Causes

Raised ALT

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Common Rarer

Raised ALP only

Consider non-hepatic causes:

physiological (adolescence (due to rapid bone turnover) pregnancy (from the placenta)) Pagets disease Fractures

Bone metastases osteonecrosis

Common

Raised y-GT

Chronic hazardous alcohol consumption drugs including

some anticonvulsants rifampicin griseofulvin

Common

Hypoalbuminaemia

Decreased Synthesis - Acute Liver Failure -Chronic Liver Disease -Acute Phase Response - Malabsorption -Malnutrition -Malignancy Increased Loss -Nephrotic Syndrome -Protein-losing enteropathy - Burns Haemodilution

-Late pregnancy -Artefact -Drip Arm

Case 1

60 y/o M, 1/52 Hx Abdo Pain & Jaundice

Bilirubin 65

ALT 84

Y-GT 235

ALP 667

Albumin 30

Case 2

22 y/o 4/7 Hx RUQ pain + Jaundice

Bilirubin 70

ALT 900

Y-GT 110

ALP 160

Albumin 30

Case 3

40 y/o with Hx of Chronic Alcohol consumption

Bili 24

ALT 31

y-GT 64

ALP 104

Albumin 30

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Case 4

66 y/o 10/12 Hx Wt Loss + Irregular Hepatomegaly

Bili 45

ALT 100

Y-GT 400

ALP 4000

Alb 25

Urea and Electrolytes

U&Es

Investigation Reference Range

Sodium 135-140mmol/L

Potassium 3.5-5mmol/L

Urea 2.5-6.7mmol/L

Creatinine 79-118

eGFR >90

Calcium 2.1-2.65

Phosphate 0.8-1.45

Albumin 35-50

Bicarbonate 22-30

Na+ Na+

Na+

Na+ Na+

Na+

Na+

Na+ Na+ Na+

K+

K+

Na+ K+

K+ K+ K+

K+

K+

Sodium

HYPERNATRAEMIA

Water loss>sodium loss

Fluid loss diarrhoea, vomiting & burns

Incorrect IV fluid replacement (excess saline)

Diabetes Insipidus

Osmotic Diuresis

Primary Hyperaldosteronism

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Sodium HYPONATRAEMIA

Is the patient dehydrated?

Yes No

Check urinary Sodium

>20mmol/L Sodium and water are lost via the kidney Renal Failure Diuretic Excess Osmolar Diuresis

500mmol/kg SIADH

due to dehydration/GI bleed

eGFR Estimated glomerular filtration rate >sensitive

indication of the degree of renal impairment STAGE GFR (ml/min)

1 >90

2 60-89

3A 40-59

3B 30-44

4 15-29

5

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Creatinine Clearance

Creatinine clearance (CCr) is calculated from the creatinine concentration in the collected urine sample (UCr), urine flow rate (V), and the plasma concentration (PCr). Creatinine clearance is calculated as removal rate per min (UCrV) divided by the plasma creatinine concentration.

Calcium

Increased calcium > Bones, Stones, Groans and Psychic moans

Decreased >SPASMODIC

Questions A 72 year old man visits his doctor for a check up and repeat prescription

of anti-hypertensives. The doctor is concerned about this man's fluid status.

Temperature 37.1 degrees, HR 110bpm, BP 90/60mmHg, Capillary refill 4 secs, JVP not visible, Skin turgor reduced, Peripheral oedema minimal, Serum sodium = 125mmol/L and Urine sodium = 33mmol/L.

Which of the following is the most likely cause?

a) Cardiac failure

b) Dermal loss

c) Diuretic excess

d) Drip arm used

e) Addison's Disease

Questions

A 66 year old man has noticed a strange tingling around his mouth for the past few weeks. It was very subtle at first but has become increasingly apparent. He also feels tired, unmotivated and low in mood. He has type 1 diabetes mellitus and uses regular NSAIDS for osteoarthritis and gout. Which single examination finding is most likely to support the diagnosis?

a) Carotid bruit

b) Neck goitre

c) Nystagmus

d) Parotid gland swelling

e) Twitching facial muscles

Questions

A 46 year old woman has had 3 days of upper abdominal pain with nausea especially after eating. She is asked to remain NBM while awaiting ultrasound scan, and given IV fluid therapy.

Saline 0.9% 1L +20mmol/L KCl/8hours

Saline 0.9% 1L/8hours

Saline 0.9% 1L +20mmol/L KCl/8hours

The surgical registrar later says that she has not had the right fluid regimen. Which is the single most likely reason for the registrar's opinion?

a) Not enough glucose

b) Not enough fluid volume

c) Too much fluid volume

d) Too much potassium

e) Too much sodium