Data interpretation Flashcards
Cause of microcytic anaemia.
Shown by low MCV – Iron deficiency.
Causes of normocytic anaemia.
Anaemia of chronic disease.
Acute blood loss.
Causes of macrocytic anaemia.
B12/folate deficiency.
Alcohol excess.
Liver disease.
Causes of thrombocytopenia.
Reduced production – infection, drugs, myelodysplasia.
Increased destruction – heparin, hypersplenism, DIC
Causes of thrombocytosis.
Reactive – bleeding, tissue damage, post-splenectomy.
Primary – myeloproliferative disorders.
Causes of hyponatraemia.
Hypovolaemic – fluid loss, Addison’s disease, diuretics.
Euvolaemic – SIADH, psychogenic polydipsia, hypothyroid.
Hypervolaemic – heart/renal/liver/nutritional/thyroid failure.
Causes of hypernatraemia.
Dehydration, drips, drugs, diabetes insipidus (opposite of SIADH).
Causes of hypokalaemia.
DIRE: Drugs (loop and thiazide diuretics). Inadequate intake. Renal tubular acidosis. Endocrine (Cushing's and Conn's syndromes).
Causes of hyperkalaemia.
DREAD: Drugs (K+ sparing diuretics, ACEi) Renal failure. Endocrine (Addison's). Artefact (clotted sample) DKA (after giving insulin K+ will drop).
Differentiating types of AKI.
Pre-renal: urea rise»creatinine rise.
Renal: urea rise «_space;creatinine rise.
Post-renal: urea rise «_space;creatinine rise and bladder/hydronephrosis may be palpable.
What can a raised urea indicate?
Kidney injury or upper GI bleed (the break down of blood releases urea into the stomach and it is absorbed into the blood stream). If a patient has a raised urea but a normal creatinine, investigate their haemoglobin.
How to identify hepatocyte injury.
Bilirubin.
ALT AST.
Alkaline phosphate.
How to identify liver function changes.
Albumin.
Vitamin K dependent clotting factors (II, VII, IX, X) – PT and INR.
Differentiating between pre-hepatic, hepatic and post-hepatic liver problems.
Pre-hepatic: raised bilirubin only.
Hepatic: raised bilirubin and AST/ALT.
Post-hepatic: raised bilirubin and ALP.
Causes of raised bilirubin only.
PRE-HEPATIC PROBLEMS.
Haemolysis – red blood cell break down.
Causes of raised bilirubin and AST/ALT.
HEPATIC PROBLEMS. Fatty liver. Hepatitis. Cirrhosis. Malignancy. Metabolic: Wilson’s disease. Heart failure.
Causes of raised bilirubin and ALP.
POST-HEPATIC PROBLEMS.
Lumen: stones, drugs causing cholestasis.
In wall: tumour, PBC, sclerosing cholangitis.
Extrinsic pressure: pancreatic/gastric cancer, lymph node.
When a patient is taking levothyroxine, what range of TSH concentration are you aiming for?
0.5-5mlU/L
Always change the dose by the smallest increment.
Decreased T4 and raised TSH.
Primary hypothyroidism – Hashimoto’s thyroiditis, drug-induced hypothyroidism.
Decreased T4 and decreased TSH.
Secondary hypothyroidism – due to pituitary tumour/damage.
Increased T4 and decreased TSH.
Primary hyperthyroidism – Grave’s disease and toxic nodular goitre.
Increased T4 and increased TSH.
Secondary hyperthyroidism – pituitary tumour.
Signs of pleural effusion on chest x-ray.
Alveolar oedema (bat wings). kerley B lines. Cardiomegaly. Diversion of blood to the upper lobes. pleural Effusion.
Normal ABG ranges.
pH 7.35-7.45 PaCO2 4.7-6.0kPa PaO2 11-13kPa HCO3- 22-26 Base excess -2 to +2
If a patient is on high flow oxygen, what should their FiO2 be?
The % O2 they’re on - 10. So if they’re on 40% O2 their FiO2 should be 30.
Levels of hypoxia.
O2 <10kPa = hypoxic.
O2 <8kPa = severely hypoxic, in respiratory failure.
Blood gases in T1 RF.
Hypoxaemia <8kPa.
Normocapnia 4.7-6.0kPa.
Blood gases in T2 RF.
Hypoxaemia <8kPa.
Hypercapnia >6.0kPa.
Blood gases in compensated T2 RF.
Hypoxaemia <8kPa.
Hypercapnia >6.0kPa.
With raised HCO3.
Cause of respiratory acidosis.
Slow shallow breathing (blue bloaters).
Cause of respiratory alkalosis.
Rapid breathing – disease or anxiety driven.
Causes of metabolic alkalosis.
Caused by vomiting, diuretics and Conn’s syndrome.
Frequent causes of metabolic acidosis.
DKA, lactic acidosis, renal failure, ethanol intoxication.
If heart rate 150 what should you consider?
Atrial flutter: 2:1 atrial contractions to ventricular so 150 (ventricular rate) may be 300 atrial.
Degrees of heart block.
First – constant PR interval >1 big square.
Second T1 – increasing PR interval, then QRS missed.
Second T2 – 2/3 P waves for each QRS.
Third (complete) – no connection between P and QRS waves.
Common drugs with narrow therapeutic index’s
Digoxin. Phenytoin. Lithium. Theophylline. Gentamicin and vancomycin.
What do you do if a patient has a high serum-gentamicin concentration?
Decrease the frequency of drug by 12h.
Management of paracetamol overdose.
Supportive – fluids.
Specific – N-acetyl cystine.
Levels of warfarin over anticoagulation and how to respond.
INR <6 – reduce dose.
INR 6-8 – stop warfarin for 2 days then reduce dose.
INR >8 – stop warfarin, give 1-5mg oral vitamin K.
What do you do if someone is bleeding when on warfarin?
– Stop warfarin.
– Give vitamin K 5-10mg IV.
– Give prothrombin complex (Beriplex).
Target INRs in patients on warfarin.
Most – 2.5
Patients with metallic heart valves or with recent thromboembolism – 3.5
