OSCE Flashcards
What is acute kidney injury?
-Significant decline in renal function over hours or days manifesting as an abrupt and sustained increase in serum urea and creatinine
What are pre-renal causes of AKI?
- Shock
- Renalvascular compromise eg NSAIDs, ACE I, renal artery stenosis
Give the main causes of renal AKI
- Acute tubulonecrosis caused by ischeamia, hypertension, thrombotic thrombocytopenia purpura
- Interstitial nephritis by drugs (NSAIDs, Abx) and toxins
- Nephritic syndrome
Post Renal causes of AKI
-Stones, neoplasm, stricture, prostate
Describe some possible clinical signs of an AKI
- Oedema
- Altered BP
- Raised JVP
- Postural hypotension
- Raised Urea, creatinine, low urine output, acidosis/hyperkalaemia
What investigations would you do in AKI?
- Bloods -> FBCs, U+Es, LFTs, glucose, Ca, clotting, ESR
- ABG to look for acidosis, hypoxia and hyperkalaemia
- urine dip
- ECG, CXR and renal US
Describe the ECG features in order of hyperkalaemia
- Peaked T waves
- Flattened P waves
- Increased PR interval
- Widened QRS
- VF
Describe the stages of alcoholic liver disease. At what stage is it irreversible?
- Fatty liver -> hepatitis -> cirrhosis
- Cirrhosis
Which liver enzymes are commonly raised in alcoholic liver disease?
- GGT
- AST:ALT >2
What is liver cirrhosis?
-Hepatocellular damage producing areas of nodular regeneration separated by fibrous septae
List some clinical signs of Alcoholic liver disease
- Hands -> Clubbing, leuconychia (low albumin), dupytens contracture, palmar erythema,
- Face -> pallor (ACD)
- Trunk -> Spider naevi, gynaecomastia (decreased liver metabolism)
- Abdo -> hepatosplenomegaly, caput medusa, ascites
- General -> jaundice, bruising (coagulopathy), anorexia
What is portal hypertension? Describe the main features
- Raised portal blood pressure >20mmHg
- SAVE (splenomegaly, ascites, varices (oesophageal, caput medusa, worsening piles) and encephalopathy
Describe portosystemic shunting in portal hypertension. Give the vessels involved in all 3 varices
- Raised portal pressure causes a backflow and increased pressure of blood as blood cannot enter portal system. portal vessels become engorged and dilated causing shifting of blood from the portal system into the systemic system.
- Oesophageal -> Left gastric vein to inferior oesophageal veins
- Caput medusa -> peri-umbilical to superficial abdo
- Haemorrhoids -> superficial rectal to inferior/middle rectal
What can be confused for caput medusa on the abdomen and how do you tell these apart?
- IVC obstruction
- blood flow down below umbilicus = portal hypertension
- Blood flow up below umbilicus = ivc obstruction
Why does portal hypertension cause encephalopathy?
- Decreased blood flow through liver decreases detoxification of blood.
- Build up of toxins in systemic system including ammonia ->cross bbb -> astrocytes clear causing glutamate to glutamine -> osmotic imbalance -> cerebral oedema
Describe the pathophysiology of ascites in liver disease
-Back pressure due to accumulation of blood causes increased hydrostatic pressure leading to fluid exudation. This causes a decrease in circulating volume and RAAS activation which enters a cycle of increased exudation and further RAAS activation. Also decreased albumin and impaired aldosterone metabolism
In broad terms what is anaemia? What general symptoms/signs does it produce?
- Decreased capacity of the haemoglobin to carry oxygen
- Fatigue, pallor, palpitations, light headedness
What are the causes of microcytic anaemia?
- TAILS
- Thalassaemia
- Anaemia of chronic disease
- Iron deficiency Anaemia
- Lead Poisoning
- Sideroblastic anaemia
Describe causes of normocytic anaemia
- Recent blood loss
- Bone marrow failure
- Early ACD
- Pregnancy
What are causes of macrocytic anaemia?
- Vit B12 deficiency
- Folate deficiency
- Reticulocytosis
- liver disease
Give some causes of haemolytic anaemia
- Autoimmune
- Malaria
- Hereditary spherocytosis/elliptosis
- burns
- G6PD deficiency
- Destruction by mechanical heart valves
Give 3 differentials for causes of iron deficiency anaemia
- Poor diet
- Menorrhagia
- Coeliac
Give 2 signs specific for iron deficiency anaemia
- Koilonychia
- Angular stomatitis
What are the causes of b12 deficiency?
- Bacterial overgrowth syndrome (increased use of b12)
- Crohns
- Pernicious anaemia
- Veganism
What are the causes of folate deficiency?
- Pregnancy
- Poor diet
- Haemolysis
- Malignancy
What are the specific symptoms in b12 deficiency?
- Glossitis
- Peripheral neuropathy
Describe the pathophysiology of asthma
-Bronchial hypersensitivity causing an exaggerated response to normally non-allergenic non-noxious stimuli resulting in mucosal oedema, mucus hypersecretion and bronchoconstriction which leads to reversible airway narrowing. Over time this lead to goblet cell hyperplasia, smooth muscle hypertrophy and airway remodelling .
What cellular/immune components are involved in asthma
- Histamine release from mast cells
- IgE and eosinophils
- Lymphocytes
Name some precipitants of asthma
- Atopy -> t1 hypersensitivity to dust, pollen, animals
- Stress -> cold air, viral urti, exercise, emotion
- Toxins -> smoking, hairspray
What are the signs and symptoms of asthma
- Cough +/- sputum
- Wheeze
- Dysponea
- Diurnal variation
What things would you want to illicit in a history to point towards asthma?
- Precipitants
- diurnal variation
- Exercise tolerance
- Life Effects
- Other Atopy
- Home/job environment
Give 2 differentials for asthma
- COPD
- Pulmonary oedema
- Bronchiectasis
Differentials of acute severe asthma
- Pneumothorax
- Pulmonary embolism
- Pulmonary oedema
- Acute exacerbation of COPD
What is atrial fibrillation? Give common signs and symptoms
- Recurrent uncoordinated contraction of the atria, normally at over 300bpm. Most beats filtered out by avn allowing ventricles to not beat at 300bpm
- Asymptomatic, chest pain, palpitations, dysponea, faintness
- Signs = irregularly irregular pulse/loss of pulse
Give some causes of AF
- Alcohol
- Ischaemic heart disease
- Thyrotoxicosis
- Hypertension
- PE/Pneumonia
- Rheumatic heart disease
What is the treatment for acute AF?
-Electrical or pharmacological cardioversion
1st line->flecainide or diltiazem
2nd line -> amiodarone
-LMWH
What does AF look like on ECG
- Narrow complex tachycardia
- Loss of P waves
- Loss of isoelectric baseline
What is cerebrovascular disease and how does it commonly present? State the main risk factor and how it causes cerebrovascular disease
- A disease of the arteries which supply the brain often resulting in a stroke of TIA.
- Often caused by hypertension which damages the blood vessels lining exposing collagen causing platelet aggregation and thrombus formation
Give 3 risk factors of cerbrovascular disease
- Hypertension
- Diabetes mellitus
- Smoking
- Family History
- Hyperlipidaemia
- AF
- Peripheral vascular disease
What are the symptoms of a total anterior stroke? Which vessel(s) is most likely involved?
- Contralateral Hemiparesis and/or sensory deficit to >2 face, arm and leg
- Contralateral homonymous hemianopia
- Higher cortical dysfunction eg dysphasia, hemispatial neglect
- Large infact in carotid/MCA
What are the symptoms of a PACS?
-2/3 of TACS usually contralateral hemiparesis and higher cortical function but deficit is less dense or incomplete
What are the symptoms of a POCS and which vessels are involved?
-One of: Cerebellar syndrome Brainstem syndrome Contralateral homonymous hemianopia -Vertebrobasilar territory
What are the symptoms of a lacuna stroke and what vessels are involved?
- Depends on where lesion is
- Pure motor (commenest) or pure sensory or mixed sensorimotor or dysarthria/decreased coordination or ataxic hemiparesis
- Involves perforating arteries around basal ganglia, thalamus, pons and internal capsule
Give 3 differential diagnoses of stroke
- SOL
- Head injury
- Altered glucose
- Infection eg encaphalitis, abscess
What is the difference between a stroke and a TIA?
-Sudden onset focal neurology which lasts less than 24 hours due to temporary occlusion of part of the cerebral circulationm Mainly caused by atherothromboelbolism from carotids
What is the ABCD2 score used for?
-Predict the risk of a stroke following a TIA
Describe how predicted FEV1 is used to assess severity
All categories are FEV/FVC<70% and symptomatic
- Mild = FEV1>80%
- Mod = FEV1 50-79%
- Sev = FEV1 30-49%
- Very Sev = FEV1<30%
What 2 conditions does COPD generally encompass? Briefly describe each
- Emyphysema -> destruction of alveolar walls producing enlarged air spaces
- Chronic bronchitis -> smooth muscle hypertrophy and mucus hypersecretion causing airway narrowing and a productive cough
What are the major causes of COPD?
- Smoking
- A1-antitrypsin deficiency
Describe the signs and symptoms of COPD. What are pink puffers and blue bloaters
- Symptoms = cough, sputum, wheeze, dysponea,
- Signs = tachyponea, hyperinflation, cyanosis, cor pulmonale,
- Pink puffer -> emphysema causing breathlessness but not cyanosis -> progressing to T1 respiratory failure
- Blue bloater -> chronic bronchitis -> Cyanosed but not breathless, rely on hypoxic drive -> type 2 resp failure
What is the MRC Dysponea score? describe its classification
- A systematic approach to grading breathlessness
1) only on vigorous exercise
2) On hurrying/walking up stairs
3) Walking slowly/has to stop
4) stops after a few mminutes
5) In normal ADLs/struggles to leave the house
Name some complications associated with COPD
- Acute exacerbations +/- infection
- Pneumothorax
- Cor Pulmonale
- Lung Carcinoma
What investigations would you perform if you suspected COPD?
- Bloods (FBCs, A1-antitrypsin, ABG)
- CXR
- ECG
- Spirometry
What signs may you see on a CXR of someone with COPD
- Hyperinflation -> >6 ribs anteriorly
- Flattened diaphragm
- Cardiomegaly
- Prominent pulmonary arteries
State the main differences between COPD and asthma
- COPD nearly always smoker
- COPD commonly presents over 35 asthma is under
- COPD common to have chronic productive cough
- COPD persistent and progressive breathlessness, asthma is variable
- Asthma wakes from nightime cough and wheeze
- Asthma has diurnal symptom pattern or day-day variability
How is an acute COPD exacerbation treated?
- O2 (titrated be careful of hypoxic drive)
- Salbutamol
- Hydrocortisone or prednisolone
- Ipratropium
- Thephylline
- Abx
- Physiotherapy
What bacterium is associated with pneumonia in a COPD patient?
-Haemophilus influenzae
What is diabetes?
- Multisystem disorder due to an absolute or relative lack of endogenous insulin resulting in metabolic and vascular complications
- T1 -> autoimmune destruction of b cells causing absolute insulin deficiency, onset is usually before puberty with polyuria, polydipsia and weightloss
- T2 -> insulin resistance resulting in b cell dysfunction causing a relative insulin deficiency, onset is in older patients with polyuria, polydipsia or coplications
What are the diagnostic tests and criteria for DM?
-Symptomatic with fasting plasma glucose >7, random plama glucose >11.1 or OGTT >11.1
What is first line teatment in T2 DM? What is its mechanism of action? Give some side effects of metformin
- Metformin
- Inhibits hepatic gluconeogenesis and increases insulin sensitivity
- NV, abdo pain, lactic acidosis
What is the second step in managing T2 DM? How does this drug work?
- Add a sulphonylurea eg gliclazide
- Stimulates B cells to produce insulin by binding to closed ATP sensitive K channels. This prevents K from exiting the cel causing depolarisation and a rise in intracellular calcium. This causes increased insulin vesicle fusion and subsequent release
How do thiazolidinediones work and give an example?
- Pioglitazone
- Stimulates PPAR-g which ultimately reduces insulin resistance by regulating adipose, muscle and liver gene expression. Also decreases hepatic gluconeogenesis,
What are GLP-1 agonists? Give an example
- Exenatide
- Stimulates GLP-1 receptors in order to enhance insulin secretion, promote satiety, slow gastric emptying and suppress glucagon secretion