5. Interactive Cases in General Internal Medicine 4 Flashcards
Signs of immediate transfusion reaction.
Fever Rigor Increased HR Decreased BP Chest pain Dark urine
(Haemolysis)
Polycythaemia DDx
Primary Polycythaemia:
Polycythaemia rubra vera
Secondary Polycythaemia:
Appropriate increase in erythropoietin:
-Chronic hypoxia e.g COPD
Inappropriate increase in erythropoietin:
- Renal (carcinoma, cysts, hydronephrosis)
- Hepatocellular carcinoma
- Fibroids
- Cerebellar haemangioblastoma
- Erythropoietin abuse amongst athletes
Relative polycythaemia:
- Dehydration
- Gaisbock’s syndrome (in obese, HTN causes hypovolaemia)
Subclassifications of Anaemia
Macrocytic Microcytic Normocytic Haemolytic (hereditary and acquired) Aplastic
Macrocytic anaemia DDx
Alcoholics May Have Liver Failure:
Alcohol
- Hx
- Raised GGT
Myelodysplasia
- Pancytopenia (low platelets/Hb/WCC)
- Bone marrow problems
Hypothyroidism
- Hx (lethargy, weight gain, constipation)
- Low T4
- High TSH
Liver disease
-Hx and Examination
Folate/B12 deficiency
-Hx (small bowel disease, ? Gastrectomy - lack of intrinsic factor produced by stomach required for B12 absorption)
[Alcohol Folate/B12 deficiency Haemolytic anaemia Hypothyroidism Liver disease Myelodysplasia Drugs: methotrexate, hydroxyurea, azathioprine, zidovudine]
Microcytic anaemia DDx
Iron Deficiency (low ferritin)
- Diet
- Blood loss (GI/UG)
Beta thalassaemia heterozygosity
[Iron deficiency: blood loss (GI - peptic ulcer, malignancy, etc; Urogenital - menorrhagia, haematuria; Hookworm; Decreased absorption - gastrectomy, small bowel disease; Increased demands - growth, pregnancy; Decreased intake - vegans)
Thalassaemia
Sideroblastic anaemia: congenital (X-linked), alcohol, drugs (isoniazid, chloramphenicol), lead, myelodysplasia
Lead poisoning
Anaemia of chronic disease (often normocytic but may be microcytic)]
Normocytic anaemia DDx
Chronic disease
- Infection, inflammation, malignancy. eg. RA
- Normal or high ferritin.
[Anaemia of chronic disease (chronic infection, inflammatory/connective tissue diseases, malignancy)
Haemolytic anaemia (may also cause macrocytic anaemia)
Hypothyoidism (may also cause macrocytic anaemia)
Pregnancy
Renal failure
Bone marrow failure]
Haemolytic anaemia DDx
Hereditary:
Haemoglobinopathies: sickle cell anaemia, thalassaemia
Membrane defects: spherocytosis, elliptocytosis
Metabolic defects: pyruvate kinase deficiency, glucose-6-phosphate dehydrogenase deficiency.
Acquired:
Autoimmune: Warm antibodies (idiopathic, SLE, lymphoma, drugs e.g. methyldopa), Cold antibodies (idiopathic, infections e.g. Mycoplasma, EBV, lymphoma)
Alloimmune: Transfusion reaction, haemolytic disease of newborn
Drugs: penicillin, quinidine
Microangiopathic haemolytic anaemia: TTP, HUS, DIC, malignant hypertension, malignancy (widespread adenocarcinoma), pregnancy complications (preeclampsia, HELLP syndrome: haemolysis, incrased liver enzymes, decreased platelets)
Artificial heart valves
March haemoglobinuria
Infection: malaria, clostridia
Paroxysmal nocturnal haemoglobinuria
Secondary to liver and renal failure
Aplastic anaemia DDx
Idiopathic
Inherited: Fanconi anaemia, dykeratosis congenita
Acquired: Drugs (cytotoxics, chloramphenicol, gold, methotrexate) chemicals, radiation, viral infection, paroxysmal nocturnal haemoglobinuria, sepsis
Thrombocytopenia DDx
Not making them - marrow infiltration by lymphomas, leukaemias, drugs, cancer., radiotherapy.
Breaking them down - DIC
Pooling in spleen - alcoholic chronic liver disease with portal hypertension.
WCC raised when?
Infection or malignancy
Ferritin
Acute phase reactant, up in inflammation etc.
50 yr old woman
Hb 90g/L
MCV 75 (decreased)
On NSAIDs for joint pain
Most likely cause?
Iron deficiency
Microcytic anaemia
On NSAIDs - therefore likely to be due to gastric erosion - inhibition of prostaglandins by NSAIDs leads to reduced protection of mucosa by acid.
40 yr old woman
Hb 110 g/L
MCV 65
Most likely diagnosis
Beta thalassaemia heterozygosity
Markers of XS alcoholic intake
High MCV
High gamma g t
Polycythaemia presentations
Headache Pruritus after hot bath Blurred vision (hyperviscosity) Tinnitus Thrombosis (stroke, DVT) Gangrene
Choreiform movements
Sickle Cell Anaemia Crises and their Managements
Acute painful crises
–>Analgesia, O2, IV fluids, Antibiotics
Stroke
–>Exchange blood transfusion (remove sickled cells)
Sequestration crises (RBC pooling)
- Lung (SOB, cough, fever)
- Spleen (exacerbation of anaemia)
- ->Splenectomy for repeated episodes of splenic sequestration
Gallstones, chronic cholecystitis
–>Cholecystectomy
Environment in which red blood cells sickle
Low oxygen tension; irreversible.
Multiple Myeloma Framework + presentation
CRAB
hyperCalcium (polyuria, polydipsia, constipation)
Renal Failure (Ur & Cr)
Anaemia (Breathlessness, lethargy - FBC)
Bone (pain, osteoporosis, fracture - DXA)
Infection Cord Compression (spastic paraparesis)
Complication of hypercalcaemia
Nephrogenic Diabetes Insipidus
…also: “Stones, Bones, Groans, Thrones, Psychiatric overtones.”
Osteoporosis
T score on a DXA scan of less than -2.5
50 yr old man Hypercalcaemia Low PTH Backache Normal ALP
Most likely cause?
Multiple Myeloma
(normal ALP - alkaline phosphatase is made by osteoblasts in myeloma; plasma cells suppress the osteoblasts, therefore normal)
Reticulocytes framework (up or down)
Anaemia with increased reticulocyte count:
- Haemolytic crisis
- Haemorrhage
Anaemia with reduced reticulocyte count: problem with bone marrow…
- Parvovirus B19 infection
- Aplastic crisis in patients with sickle cell anaemia
- Blood transfusion
Definition of Diabetes Mellitus
Fasting glucose of more than 7 (as after this level the rate of retinopathy is significantly increased)
Random glucose of at least 11.1
HbA1c more than 48 (or greater than 6.5% DCCT)
Definition of Impaired glucose tolerance
Pre-diabetic state of hyperglycaemia associated with insulin resistance and increased risk of cardiovascular pathology. May precede T2DM by many years.
Give 75g OGTT
2-hr glucose: 7.8-11
Stereotypical Diabetic Presentations
Type 1:
Young, thin, insulin deficiency - wt loss, ketones, acidosis
Type 2:
Older, overweight, obese, insulin resistant
Type 3c:
Patients with impaired pancreatic function e.g. pancreatectomy. V difficult to manage; also have decreased glucagon.
45 yr old man
Lethargy, fatigue, polyuria, polydipsia
Urinalysis: no ketones, glucose +++
Random glc: 18
How to treat?
Metformin
1st drug in treatment of T2 diabetes after lifestyle and diet advice.
(Then sulfonylurea, then DPP-IV inhibitor, then insulin if not controlled by tablets. If patient is overweight, or want to avoid hypoglycaemia, think about GLP-1 agonist.)
Metformin action
Reduces insulin resistance
Sulfonylurea action
Stimulate insulin release
DPP-IV inhibitor action
Inhibits the enzyme that break down GLP-1
GLP-1 agonist action
Stimulates release of protein that increases insulin secretion, decreases glucagon secretion, reduce appetite, causes some wt loss.
Sliding scale/Variable rate IV insulin infusion
Used when patient is in worse condition, e.g. not eating, unwell, surgery/sepsis etc
Blood glucose (mmol/L)/Insulin Dose (units/hr)
0-3.9 / 0.5 4-7.9 / 1 8-11.9 / 2 12-15.9 / 4 16-19.9 / 6 20+ / 8-12 (Consult doctor)
Graves’ Disease: Presentation, TFTs and Ix
Wt loss Good appetite Irritability Palpitations Irregular periods
O/E: Tremor Proptosis Smooth goitre Pretibial myxoedema
High free T4/T3, suppressed TSH
Next investigation: TSH receptor stimulating antibody
TPO antibodies
Marker of autoimmunity
Uptake in different thyroid conditions:
Graves’
Thyroiditis
Toxic Nodular Goitre
Graves’: diffuse increased uptake
Thyroiditis: no uptake
Toxic Nodular Goitre: One spot of increased uptake, absent elsewhere (autonomous nodule)
Thyroid Cancer Hx and Ex, RF
Lumps
Risk factors: Radiation FHx Rapid enlargement/compression Lymphadenopathy
Mets (lung, follicular thyroid ca)
Thyroid Ix and Rx
USS
FNAC (Uptake scan: cold nodules)
MDT
Surgery: Papillary Follicular Medullary Anaplastic (poor prognosis)
Thyroxine, Radioiodine
Bitemporal Hemianopia cause
Pituitary tumour compressing optic chiasm
30 yr old female
Amenorrhoea
Galactorrhoea
Bitemporal Hemianopia
Diagnosis and Treatment
Prolactinoma compressing optic chiasm.
Cabergoline: dopamine agonist
50 yr old man
Headache, sweating
Poor sleep, snoring - obstructive sleep apnoea
Tingling in fingers - carpal tunnel syndrome
Initial test: High IGF-1
Next investigation?
OGTT
suspect acromegaly
Suspected Acromegaly Tests
- IGF-1
2. OGTT
Insulin Tolerance Test
Test of Pituitary Function
In normal, give insulin –> decreased blood glucose –> hypoglycaemia –> rise in cortisol and growth hormone.
Dynamic pituitary function test
Oral Glucose Tolerance Test
Test for Acromegaly
75g Glucose
In normal, this will suppress GH. If doesn’t happen, consistent with acromegaly.
Dexamethasone Suppression Test
Test for Cushing’s
In normal, dexamethasone suppresses ACTH and Cortisol. If not low, abnormal –> Cushing’s
Short Synacthen Test
Test for adrenal insufficiency
Normal: ACTH –> increased cortisol.
Discriminatory signs of Cushing’s
Bruising
Myopathy
Purple Striae more than 1cm wide (due to wt gain and thin skin)
DM/HTN/Osteoporosis at young age.
Amenorrhoea/Oligomenorrhoea
Pregnancy
-Urine BHCG
Hypothalamus
-? Excessive exercise, low BMI
Pituitary
- Excess prolactin
- Low LH/FSH
Thyroid (hyper/hypo)
-TFTs
Ovaries
- PCOS: Excess androgens or hirsutism
- Ovarian Failure: High FSH (low oestradiol –> less negative feedback –> high FSH)
Hypokalaemia Presentation and DDx
Presentation:
Polyuria (caused by nephrogenic diabetes inspidus –> ADH resistance)
Weakness
Arrhythmia
DDx: GI: vomiting Diuretics Primary hyperaldosteronism (bilateral hyperplasia or Conn's) -aldosterone:renin ratio
(Aldosterone stimulates sodium absorption and potassium excretion)
Hypernatraemia
High plasma osmolality [= 2 X (Na + K) + Ur + glc]
High urine osmolality?
- Dehydration (elderly/children)
- HHS (urine high osm: glycosuria), Type 2 diabetes
Low urine osmolality
-Diabetes insipidus (DIlute urine, osm , 300)
Low Ca
Low phosphate
High PTH
Vitamin D deficiency
PTH
Parathyroid hormone
(Phosphate trashing hormone)
Increased PTH –> Increased Ca, Decreased Phosphate
High Ca
Low phosphate
High PTH
Primary Hyperparathyroidism
High Ca
Normal Phosphate
Low PTH
Malignancy/Myeloma
Low Ca
High Phosphate
Low PTH
Hypoparathyroidism
Low Ca
High Phosphate
High PTH
Chronic Kidney Disease
(PTH high because calcium is low; Phosphate high due to renal failure, therefore no hydroxylation of Vit. D in kidneys. No renal filtration of phosphate)
AKI framework
Pre-renal
- Hypovolaemia
- Sepsis
Renal
- Drugs
- ? Active urine sediment: blood and protein in the urine (glomerulonephritis)
Post-renal
-USS (?Obstruction)
Renal artery stenosis
Asymmetrical Kidneys
Magnetic Resonance Angiography
Deterioration of renal function with ACE inhibitors (bilateral RAS)
Types of psoriatic arthritis
Oligoarticular Polyarticular Arthritis Mutilans Spondyloarthritis Distal interphalangeal predominant
Oligoarticular Psoriatic Arthritis
Affects 70% of patients
Generally mild
Does not occur in the same joints on both sides of the body
Usually only involves fewer than 3 joints.
Polyarticular Psoriatic Arthritis
25% of cases
Five or more joints on both sides of the body simutaneously
Arthritis Mutilans
Less than 5% of patients
Severe, deforming and destructive
Can progress over months or years causing sever joint damage
Spondyloarthritis Psoriatic Arthritis
Characterised by stiffness in the neck or the sacroiliac joint of the spine; can also affect hands and feet
Distal interphalangeal predominant Psoriatic Arthritis
Characterised by inflammation and stiffness in the joints nearest to the ends of the fingers and toes; nail changes often marked.
