Core Conditions Continued 2 Flashcards
What does aldosterone do?
Regulates salt and water balance by increasing the retention of sodium and water, and increasing the excretion of potassium.
How is Addison’s diagnosed?
Short synacthen test: measure baseline cortisol, give synthetic ACTH, measure cortisol again after 30 and 60 minutes.
Failure of cortisol to rise by at least double = primary adrenal insufficiency
Addison’s disease can cause which of the following:
- Metabolic alkalosis with normal anion gap
- Metabolic alkalosis with high anion gap
- Metabolic acidosis with normal anion gap
- Metabolic acidosis with high anion gap
Metabolic acidosis with normal anion gap
Tx for Addison’s:
Hydrocortisone to replace cortisol
Fludrocortisone to replace aldosterone
Crisis: IV steroids, IV fluids, correct hypoglycaemia, careful monitoring
Carry a medical ID tag, follow sick day rules (double steroids if temp >38 or having D&V)
What is cushing’s syndrome?
Give 3 causes:
Syndrome of excessive cortisol
Primary: adrenal tumour secreting cortisol
Secondary: pituitary tumour secreting ACTH (Cushing’s Disease!)
Iatrogenic: corticosteroids
4 functions of cortisol and the symptoms these cause in cushing’s syndrome:
- Anti-insulin → hyperglycaemia
- Lipolysis and fat mobilisation → buffalo hump, central adiposity
- Muscle protein degradation → Muscle wasting
- Anti-inflammatory → immunosuppression, easy bruising, poor wound healing
Cushing’s Syndrome Presentation: (10)
“CUSHINGOID”
C - cataracts
U - ulcers
S - skin striae/bruising/thinning
H - hypertension and hirtuism
I - infection
N - necrosis of femoral head
G - glycosuria
O - obesity/osteoporosis
I - irritability/depression/lethargy/psychosis
D - diabetes
How do you diagnose Cushing’s syndrome?
24 hour urinary cortisol test
Morning/midnight cortisol (if diurnal variation is preserved → unlikely to be cushing’s)
Dexamethasone suppression test
What is Conn’s syndrome?
3 signs?
A unilateral adrenal adenoma that secretes excessive aldosterone.
Hypernatraemia, hypertension, hypokalaemia.
What is a phaeochromocytoma?
A rare adrenal tumour that secretes cathecholamines.
Results in: episodic headaches, paroxysmal hypertension, excessive sweating, tachycardia
What is acromegaly?
Excessive growth hormone, most commonly caused by a pituitary adenoma.
3 symptoms of tissue overgrowth in acromegaly:
- Prominent forehead and brow (frontal bossing)
- Macroglossia
- Large hands and feet (shoes stop fitting, ring too small)
What visual defect might acromegaly cause? Why?
Bitemporal hemianopia
Acromegaly is most commonly caused by a pituitary adenoma. If the adenoma is large, it’ll press on the optic chiasm.
Ix for acromegaly:
Initial screening: insulin-like growth factor (raised)
OGGT whilst measuring growth hormone (high glucose SHOULD suppress growth hormone)
MRI pituitary
Visual fields testing
Other than surgical removal of the pituitary tumour, how might you treat acromegaly?
Block growth hormone with:
- Somatostatin
- Dopamine agonists
- Pegvisomant
What is carcinoid syndrome?
Occurs due to neuroendocrine tumours secrete hormones that result in diarrhoea, SOB and flushing.
What metabolic abnormality does renal failure most commonly cause?
Raised anion gap metabolic acidosis
What is anti-glomerular basement membrane disease? (AKA goodpasture’s syndrome)
A rare small vessel vasculitis associated with pulmonary haemorrhage and rapidly progressive glomerulonephritis.
Renal biopsy will show linear IgG deposits along the GBM. Tx is plasma exchange and steroids.
What is haemolytic uraemic syndrome (HUS)?
A triad of: AKI, haemolytic anaemia, thrombocytopenia
Most commonly secondary to E.coli infection in children. Toxins (shiga toxin) released by E.coli trigger thrombosis in small blood vessels.
Typically onset 5 days after diarrhoea.
2 causes of acute tubular necrosis:
- Ischaemia due to hypoperfusion (shock, sepsis, dehydration)
- Direct damage from toxins (radiology contrast dye, gentamicin, NSAIDs)
Ix in acute tubular necrosis: (1)
Muddy brown casts on urinalysis
What metabolic abnormality might salicylate poisoning cause?
Raised anion gap metabolic acidosis
What is Alport’s syndrome?
An X-linked inherited condition.
A defect in the gene that codes for type IV collagen results in an abnormal glomerular basement membrane.
How does Alport’s syndrome present?
Usually presents in childhood with:
- progressive renal failure
- microscopic haematuria
- bilateral sensorineural deafness
Why might a renal transplant fail in a patient with Alport’s syndrome?
May have anti-GBM antibodies.
What is the emperical treatment for epididmo-orchitis caused by an STI?
IM ceftriaxone stat dose + doxycycline 10-14 days
What is the most common cause of acute epididmo-orchitis in sexually active younger adults?
Chlamydia
What is Paget’s disease?
A disorder of excessive bone turnover, leading to patchy areas of high density (sclerosis) and low density (lysis).
Results in enlarged misshapen bones with structural problems and increased risk of pathological fractures.
Mainly affects the axial skeleton.
4 XR findings in Paget’s disease:
- Bone enlargement and deformity
- Osteoporosis circumscripta = defined osteolytic lesions
- Cotton wool appearance of the skull
- V shaped osteolytic defects in long bones
How does Paget’s disease affect blood results?
High ALP (all other LFTs normal)
Normal calcium
Normal phosphate
Why is septic arthritis an emergency?
Can cause irreversible joint damage within 24 hours
What is the acronym used to remember Kocher’s criteria?
NEWT
Non-weight bearing
ESR >40 in first hour
WBC >12,000 cells/mm3
Temp >38.5
How do you treat septic arthritis?
IV flucloxacillin ± clindamycin for 4 weeks
Joint washout
Debridement
Pain relief
Splinting
Physio
What is SLE?
An autoimmune condition in which anti-nuclear antibodies attack proteins in cell nuclei triggering systemic inflammation.
Which antibody is the most specific for SLE?
Anti-dsDNA
Complications of SLE: (6)
CVS disease - HTN and coronary artery disease (leading cause of death)
Infection
Pulmonary fibrosis
Anaemia of chronic disease
Recurrent miscarriage
Lupus nephritis → end stage renal failure
Symptoms of SLE:
- Photosensitive malar rash (butterfly shape on face)
- Fever
- Fatigue
- Weight loss
- Raynauds
- Arthritis & joint pain
Tx of SLE: (4)
NSAIDs (pain relief)
Hydroxychloroquine (first line for mild SLE)
Steroids (prednisolone)
Suncream and sun avoidance
What is Sjogren’s?
An autoimmune condition that affect exocrine glands → dry mucous membranes
Which antibodies are present in Sjogren’s?
Anti Ro
Anti La
ANA
What is Marfan’s syndrome?
An autosomal dominant condition affecting the gene responsible for creating fibrillin, an important component of connective tissue
Px of Marfan’s syndrome: (7)
Tall stature
Long neck
Long limbs
Long finger (arachnodactyl)
High arch palate
Hypermobility
Pectus carinatum or excavatum
5 complications of Marfan’s:
Aortic or mitral valve prolapse → regurgitation
Aortic aneurysms
Joint dislocations
Scoliosis of the spine
What type of anaemia does iron deficiency cause?
Microcytic anaemia
Give five causes of normocytic anaemia:
Anaemia of chronic disease
CKD
Aplastic anaemia
Haemolytic anaemia
Acute blood loss
What is acute lymphoblastic leukaemia?
Malignant proliferation of lymphoid progenitor cells
What kind of anaemia would beta thalassaemia cause?
Microcyctic
Give 6 blood transfusion reactions:
Haemolytic febrile reaction
Minor allergic reaction
Anaphylaxis
Acute haemolytic reaction
Transfusion-associated circulatory overload (TACO)
Tranfusion related acute lung injury
What is transfusion associated circulatory overload?
Fluid overload and pulmonary oedema due to rapid infusion of blood
Lead poisoning can cause what type of anaemia?
Microcytic
3 causes of macrocytic megaloblastic aneamia:
folate deficiency
b12 deficiency
cytotoxic drugs
5 causes of normoblastic macrocytic anaemia:
Liver disease
Hypothyroidism
Alcohol excess
Reticulocytosis
Pregnancy
Define the following types of miscarriage: missed, threatened, inevitable, incomplete, complete
Missed: fetus dead, no symptoms, cervix closed
Threatened: bleeding, cervix closed, fetus alive
Inevitable: bleeding, cervix open
Incomplete: retained products, cervix open
Complete: no retained products
After ovulation, how does pregnancy occur? (days 0 to 8)
Day 0 = ovulation - the corpus luteum starts producing oestrogen and progesterone
Day 1 = fertilisation (within 12 to 24 hours of ovulation)
Cells begin to divide, forming a blastocyst by day 4
Day 5 = implantation - the blastocyst implants, helped by a low oestrogen:progesterone ratio
Day 6 = the trophoblast (outer cells of the blastocyst) burrows into the endometrium
Day 8 = the trophoblast cells start producing hCG, which tells the corpus luteum a successful fertilisation and implantation has occurred so to carry on making oestrogen and progesterone (suppressing the development of any other new follicles)
How does the levels of oestrogen, progesterone and hCG change throughout pregnancy?
Where are these hormones produced?
In weeks 0 to 9 the corpus luteum is producing oestrogen and progesterone - levels rise continuously
Meanwhile, the trophoblast is producing hCG, this peaks at week 9 and then begins to fall…
This triggers the corpus luteum to degenerate and instead, the placenta now takes over…
Weeks 9 to 40 the placenta produces oestrogen, progesterone and a small amount of hCG
What is the hormone hPL? Why is it produced in pregnancy?
Human placental lactogen - made by the placenta to counteract the mother’s insulin in order to provide the baby with enough glucose
Changes to the cardiovascular system in pregnancy: (6)
- 30 to 50% increase in blood volume → decreased haematocrit and physiological anaemia of pregnancy
- Increased HR by ~20 bpm to increase cardiac output (and push the extra blood around)
- Slight fall in BP due to vasodilation (caused by progesterone)
- Heart nudged slightly upwards by uterus, point of maximum intensity moves slightly to the left
- Uterus presses on pelvic veins → varicose veins and swelling in legs and ankles
- Uterus presses on inferior vena cava when laying down → hypotension (avoided by lying on your side)
How are the kidneys affected by pregnancy?
During pregnancy the blood volume increases by 30-50%.
This increases the blood flow to the kidneys, increasing the GFR and therefore increasing urinary output. This explains why pregnant women experience urinary frequency.
To compensate, the kidneys and ureters enlarge causing physiological hydropherosis and hydroureter.
High progesterone levels also cause hypermotility of the ureters.
The enlarged kidneys are at greater risk of urinary stasis and therefore increased risk of an upper UTI.
How does pregnancy affect the lungs?
The uterus presses on the lungs → SOB.
Progesterone causes ligaments in the thorax to relax → increased diameter of the ribcage
Increased diameter of the ribcage → increased tidal volume
Increased tidal volume → drop in blood CO2 levels
Lower CO2 → mild alkalosis
Mild alkalosis is advantageous for gasesous exchange across the placenta
How does oestrogen affect the upper respiratory tract in pregnancy?
Oestrogen → increased vascularisation & capillary engorgement
→ nasal stuffiness, nose bleeds, sinus congestion
What causes the ‘waddling gait’ seen in pregnancy?
Progesterone and relaxin (produced by the placenta) cause ligaments in the pelvis (sacroiliac joints and symphsis pubis) to relax in preparation for fetal passage through the birth canal in labour.
How does pregnancy affect the GI system?
Hormonal changes lead to smooth muscle relaxation and decreased peristalsis → constipation and bloating
Hormonal changes can also lead to relaxation of the lower oesophageal sphincter → reflux
You can also get morning sickness
How does pregnancy affect breast tissue?
Oestrogen and progesterone trigger breast development which may result in symptoms of tingling, fullness and tenderness.
Oestrogen also stimulates prolactin secretion from the anterior pituitary. High levels of progesterone inhibits the affects of prolactin until after the baby is born. Once born, prolactin will stimulate milk letdown from the breasts.
What is the linea nigra seen in pregnancy?
The linea alba is a stripe of fibrous tissue that runs down the centre of the abdomen.
In pregnancy, the anterior pituitary secretes increased melanocyte-stimulating hormone which darkens the linea alba → linea nigra
It also darkens the nipples.
How is the thyroid affected by pregnancy?
The thyroid secretes more thyroid hormones to increase the cellular basal rate and meet the increased demands of the pregnancy
Why are pregnant women at a greater risk of VTE? Explain the physiology of this:
Oestrogen promotes blood clotting in two ways:
- Increases plasma fibrinogen and the activity of coagulation factors
- Decreases the activity of antithrombin III
This makes pregnancy a hypercoagulable state → increased risk of VTE
What is the difference between placenta accreta, placenta increta and placenta percreta?
Placenta accreta: placenta attaches to the myometrium
Placenta increta: placenta grows into the myometrium (inner muscular layer)
Placenta percreta: placenta invades through the perimetrium (outermost layer of the uterus)
Criteria for surgical management of an ectopic pregnancy: (6)
- Foetal heartbeat
- Size > 35mm
- Ruputred
- Pain
- hCG >5,000 IU/L
- Co-existing intrauterine pregnancy
How are perineal tears managed?
1st degree: no repair required
2nd: suture on the ward by suitably experienced clinician
3rd: repair in theatre
4th: repair in theatre
Which antibiotic should you NOT give to a breastfeeding woman?
Ciprofloxacin, tetracycline, chlroamphenicol, sulphonamides
Two psychiatric drugs that are contraindicated in breastfeeding:
Lithium
Benzodiazepines
When should you advise a higher dose of folic acid prior to and during pregnancy?(8)
If any of the following apply:
- Patient’s partner has NTD
- Prev pregnancy affected by NTD
- Family hx of NTD
- Patient taking antiepileptics
- Patient has coeliac disease
- Patient has diabetes
- Patient has thatlassaemia trait
- Patient has a BMI >30
What kind of anaemia does myeloma cause?
Macrocytic
How do you treat hypoglycaemia?
Conscious and able to swallow → oral glucose e.g. 40% glucose gel, repeat after 15 mins up to a maximum of 3 times
Decreased consciousness → IM glucagon in the community, IV glucose 10% or 20% in secondary care/whenever IV access is possible
NB: IM glucagon can cause flushing and nausea
Which diabetes type II medication is approved for use in CKD?
Sitagliptin (DDP4i)
Contraindications for pioglitazone: (4)
DKA
Hx of heart failure
Previous or active bladder cancer
Uninvestigated macroscopic haematuria
What are the two most common causes of hypercalcaemia?
- Primary hyperparathyroidism
- Malignancy
What is the first line emergency treatment for hypercalcaemia?
- Increase circulating volume with 0.9% saline to help increase urinary output of calcium