Endocrinology_Medicine Flashcards
Hyponatremia - Sx? Ix & Approach? What happens if you correct Na too fast?
Sx: confusion, altered GCS, headaches, seizures, encephalopathic
Ix: fluid status, U&E, paired osmolalities (urine, serum)
Fluid status:
- HYPOvolaemic (dehydrated) - WASTING (diarrhoea/vomiting, diuretics) –> IV fluids
- EUvolaemic (normal) - ENDOCRINE (SIADH, hypothyroidism, Addison’s) –> fluid restrict + Tx underlying cause
- HYPERvolaemic (fluid overload) - FAILURE (liver, renal, heart) –> fluid restrict + Tx underlying cause
Urine Na:
- <20 mmol/L –> hypovolaemia (increased Na reabsorption in kidneys –> increasing H20 retention –> reducing urine Na)
- >20 mmol/L –> SIADH (BUT if on diuretics, urine Na can’t be interpreted) –> fluid restrict
Na corrected too fast (>10) = osmotic demyelination syndrome (central pontine myelinolysis) –> pseudo-bulbar palsy, paraparesis, locked-in syndrome
Potassium homeostasis - areas involved? Hypo/hyper? Appearance on ECG? Hyper Tx?
Areas involved:
- Dietary intake
- Absorption in GI tract
- Adrenals & kidneys - regulate serum K concentration
HYPOkalaemia:
- Poor dietary intake, vomiting/diarrhoea
- Diuretics - loop/thiazide (block channels causing K reabsorption)
- Hyperadrenalism (Conn’s, bilateral adrenal hyperplasia, Cushing’s)
- Conn’s/BAH - excess aldosterone - NOTE: Aldosterone promotes reabsorption Na, excretion K
- Cushing’s = excess cortisol –> off-target effect on mineralocorticoid receptors –> mimics aldosterone
HYPERkalaemia:
- false = HAEMOLYSIS –> repeat sample
- Kidney failure e.g. on dialysis (kidneys = main route to remove K)
- Anti-HTN/diuretics
- ACEi/ARB - reduce kidney hyperfiltration, mainly a risk if CKD
- K+-sparing diuretics e.g. spironolactone/amiloride
- Addison’s disease (failure - can’t produce enough cortisol/aldosterone)
- NOTE: appearance on ECG = tented T-waves, broad QRS, prolonged PR interval
Hyperkalaemia Tx:
- Protect heart - IV 10-30ml 10% Ca Gluconate (repeat /15m, x5 MAX)
-
Reduce K+:
- 1st line - 10U Actrapid (insulin > drive K into cells) AND 100mL 20% glucose (to prevent hypo)
- 2nd line - 5mg Salbutamol NEB (b-agonist)
- Ix cause: drug chart, U&E (kidney funct), short SynACTHen test (Addison’s)
Calcium homeostasis?
Hyper Sx? Ix & causes? Mx?
Hypo Causes? Sx? Ix? Mx?
Hormone production:
-
Parathyroid gland - PTH –> INCREASE Ca:
- Bone resorption
- GI absorption
- Kidney - decreased excretion, increases 1alpha-hydroxylation (vitD activation)
- Vit D3 aka cholecalciferol (UV)/ergocalciferol (diet)
- In Liver –> 25-OH(D) aka calcidiol
- In Kidney + 1alpha-hydroxylase –> 1,25-OH2(D) aka Calcitriol (activated vitD) –> INCREASE Ca
- GI absorption
- Kidney - decreased excretion
HYPERcalcemia
-
Sx:
- Stones - urinary tract calculi
- Bones - fractures
- (Abdo) moans - dyspepsia
- Thrones - polyuria, constipation
- (Psych) overtones - depression, psychosis
- Ix - check PTH:
- Low - hypercalcemia of malignancy (PTH axis is functioning normally) - bone mets, PTHrP (released by lung SCC), myeloma (CRAB)
- Normal/high - primary hyperparathyroidism (as if serum Ca high, PTH should be low) - adenoma, hyperplasia, MEN 1&2
- Other:
- Fluid status, ECG (short QT), protein electrophoresis, 24hr urinary Ca (familial hypocalciuric hypercalcemia)
- Bloods - bone profile (Ca, PO4), U&E
- Imaging: CXR
- Mx:
- IMMEDIATE = aggressive IV 0.9% fluid resus (4-6L over 24krs), repeat Ca
- Tx underlying cause:
- Parathyroid adenoma - minimally invasive surgery (subtotal/total parathyroidectomy)
- Malig - Zalendronate/Pamidronate (inhibit osteoclast activity), slow infusion
- Other:
- If bone mets –> bisphosphonates
- If renal failure –> Cinacalcet (reduce PTH)
- Recheck serum Ca @day 2 –> 4
HYPOcalcaemia
- Causes:
- Hypoparathyroidism (PO4 high, PTH low)
- Pseudohypoparathyroidism (PO4 high, PTH high) = PTH resistance
- CKD (high PO4, PTH high, ALP high)
- Vit D def (rickets/osteomalacia, low/normal PO4, high PTH, high ALP)
- Hypomagnesaemia (low/normal PO4, low/normal PTH, normal ALP)
- Presentation:
- Peri-oral numbness, digital paraesthesia, dermatitis
- +ve Trousseau’s (BP cuff 20 over SBP for 3mins –> salt bae hand), Chovstek signs (tap over the masseter muscle in the inferior pre-auricular area)
- Laryngospasm (wheeze, dysphagia, muscle cramps)
- Confusion, seizures, prolonged QT
- Ix: serum Ca, PO4, Mg, PTH, U&E, Vit D
- Mx: PO/IV replacement of Ca
If a patient has metformin & CKD when to stop metformin?
eGFR <30
If on insulin - what to do about driving?
Inform DVLA, must be able to record CBG every 2hrs
Tired, thirsty and irritable, wees alot (very pale) - Dx?
What is there Serum Sodium lvl?
Diabetes insipidus
Ix: hypernatraemia
Large hands + jaw + bitemporal hemianopia - Dx?
Acromegaly (anterior pituitary macroadenoma)
Young female, resistant HTN, hypokalaemia - Dx?
Conn’s syndrome (hyperaldosteronism)
Headache, sweating, tachy, HTN - Dx?
Phaeochromocytoma
Hyperparathyroidism sub-categories?
- Primary - PTH secretion from primary parathyroid tumour/ectopic secretion from another tumour (high Ca, high PTH)
- Secondary - PT hyperplasia to maintain control of hypocalcemia, normally from CKD (low Ca, high PTH, normal -ve feedback)
- CKD –> bone profile, parathyroid hormone lvl every 3-6 months
- Tertiary - prolonged secondary, becomes irrepressible by serum Ca lvls. Mostly kidney transplant patients (high Ca, very high PTH)
Hoarse voice post-thyroidectomy - why?
Recurrent laryngeal nerve injury
Low Ca, high PO4, high PTH, short fingers
Pseudohypoparathyroidism (similar features to secondary hyperparathyroidism - consider if CKD or vit D deficiency does not explain the presentation)
Facial twitching when tapping anterior to the tragus - sign?
Chvostek sign (hypocalcaemia)
Diabetes: presentation? RFs? types? criteria for Dx? Mx? Complications?
Presentation: polyuria, polydipsia, dehydration
- Ketosis - malaise, vomiting
- FHx, other endo disorders
- If known DM:
- Previous DM control (hyp/hyper)
- Micro/macrovascular complications
- Diabetic eye disease (Dx & Tx)
RFs: overweight, FHx (DM), PMHx (GDM), PCOS, HTN, dyslipidemia, CVD
Criteria for Dx (repeat test needed for Dx):
- Fasting plasma glucose of ≥7.0 (normal ≤6)
- OGTT (BM 2hours after 75g glucose-load)/ Sx + random plasma glucose of ≥11.1mmol/l (normal <7.8)
- HbA1c ≥48mmol/mol (≥6.5%) - not for young/T1DM, acutely ill, haem disease, preg, iatrogenic
T1DM Mx: exogenous insulin to avoid DKA & long-term complications
- Diet - lower fat, higher carbs = counting carbs (adjust insulin around diet rather than limiting eating)
- Diabetic specialist nurse - EDUCATE:
- Self-adjust dose - DAFNE course for T1DM (D for DM)
- Fingerprick glucose
- Calorie intake & carb counting
- Phone support
- Don’t stop insulin during acute illness, maintain calorie intake
- Insulin regimens:
- 1st line - Basal-bolus regimen
- Basal (background) - BD insulin detemir (or Levemir/Lantus/Tresiba) as basal insulin
- Bolus (before meals) - analogue rapid-acting insulin e.g. insulin Lispro (Humalog)/Aspart (Novorapid)/Neutral (Actrapid)
- Other:
- BD biphasic (premixed insulin, hypos common) e.g. Novomix, Humulin M3, Humalog Mix
- OD before bed long-acting (for T2DM)
- NOTE: intermediate-acting insulin e.g. Humulin I, Insulatard
- 1st line - Basal-bolus regimen
T2DM Mx:
- 1st line - Lifestyle changes - DESMOND course for T2DM (D for DM), dietician input, self-BM monitoring (individual HbA1c target <6.5)
- HbA1c targets:
- No hypoglycaemics - 48mmol/mol
- Hypoglycaemics - 53mmol/mol
- Escalate Tx - 58mmol/mol
- HbA1c targets:
- Medication:
- 2nd - Metformin (SEs: diarrhoea, LA - avoid if eGFR <30)
- 3rd - ADD Sulphonylurea e.g. Gliclazide (SEs: hypoglycaemia, weight gain)
- 4th - ADD other DM med:
-
Pioglitazone (SEs: hypoglycaemia, weight gain, oedema, fractures in elderly)
- C/I in HF, bladder cancer
-
SGLT-2 inhibitor e.g. Empagliflozin (SEs: Hypoglycaemia, weight loss, UTI)
- Not recommended in impaired renal funct
- DPP-4 inhibitor e.g. Linagliptin (APPROVED FOR USE IN CKD, weight neutral)
-
GLP-1 analogues e.g. Exenatide/Liraglutide (SE: weight loss - useful if BMI >35; vomiting)
- Not recommended in impaired renal funct
-
Pioglitazone (SEs: hypoglycaemia, weight gain, oedema, fractures in elderly)
- 5th - If on triple therapy & not providing control –> commence insulin
- CVD risk Mx - anti-HTN, anti-lipid, QRISK-3 score
- Diabetic nephropathy Mx:
- Monitor albumin-creatinine ratio (ACR)
- Consider ACEi/ARB early
- Diabetic neuropathy Mx:
- Annual Sx review (erectile dysfunction, autonomic neuropathy - orthostatic hypotension, gastroparesis, bladder emptying difficulties)
- Annual foot screen + specialist foot Mx, monitor for diabetic foot/ulcers ± amputation
- Diabetic retinopathy: retinal screen annually (age ≥12yrs)
- Background: need to tighten control
- Venodilation, microaneurysms (dots), hard exudates (lipid deposits)
- Tx: tighten glycaemic control, refer if near macula
- Pre-proliferative (mild) - soft exudates (cotton wool spots e.g. infarcts)
- Proliferative - neovascularization (+ floaters, reduced acuity)
- Tx: pan-retinal photocoagulation
- Diabetic maculopathy - hard exudates, oedema (+ blurred vision, reduced acuity)
- Tx: intravitreal triamcinolone acetonide decreases macula oedema
- NOTE: Pre-diabetic –> refer to diabetes prevention programme (DPP)
- Background: need to tighten control
Diabetes complications:
- Microvascular:
- Eye - diabetic retinopathy (± cataracts, glaucoma)
- Kidney - diabetic nephropathy
- Neuropathy - damage to PNS –> diabetic neuropathy (peripheral neuropathy - glove & stockings distribution) –> diabetic ulcers/gangrene
- Macrovascular:
- Brain - stroke/TIA/cog impairment
- Heart - coronary heart disease
- Extremities - PVD, diabetic ulcers/gangrene
Acromegaly cause? presentation? Ix? Mx? Complications?
Cause: macroadenoma in anterior pituitary
Presentation: coarse facial features
- Skin (acanthosis nigricans - thick & dark in creases), sweating, carpal tunnel syndrome (bilateral)
- Arthropathy, sleep apnoea, reduced sexual functioning, visual field defects (bitemporal hemianopia)
- Assoc: DM, HTN, MEN type 1 (15%)
Ix:
- Bedside: CN VI palsy, urine dip (glucose), ECG (cardiomyopathy)
- Bloods: elevated IGF-1, GH lvl during OGTT (not suppressed in acromegaly)
- Imaging: MRI brain (macroadenoma), sleep studies, colonoscopy (screening), visual field testing (driving)
Mx:
- Transsphenoidal hypophysectomy (curative)
- Medical: somatostatin analogue (octreotide)
- External pituitary radiotherapy (long-term 5-10yrs)
Complications:
- General: HTN, DM, carpal tunnel syndrome, sleep apnoea, colorectal cancer, LVH/cardiomyopathy/IHD
- Anterior pituitary hypofunction: hypogonadism
- Local compressive: bitemporal hemianopia
Perioperative DM Mx?
Variable insulin infusion for 30-60 mins after starting SC insulin to avoid iatrogenic DKA
SGLT2 inhibitors (dapagliflozin) S/E?
Increased yeast/UTIs, hypoglycaemia, weight loss
Pioglitazone S/E? C/Is?
hypoglycaemia, weight gain, fluid retention (oedema), assoc with bladder cancer, osteoporosis (elderly - fractures)
C/Is: HF, bladder cancer
Sulphonylureas (oral) or insulin (sc) S/E?
Weight gain & hypoglycaemia