What can result in hypoglycaemia, how is it investigated?
Hypoglycaemia - inevitable in pt on insulin therapy
- blood glucose level <3.5mmol/L
- cognitive function will begin tp decline below 3mmol/L and 2.8 is considered as severe hypoglycaemia
What investigations are done for thyroid conditions
- TFTs
- low T3&4 = hypothyroidism
- high T3&4 = hyperthyroidism
- normal T3&4 but abnormal TSH = subclinical hypo/hyperthyroidism
- high TSH despite normal/high T3/T4 could also be indicative for TSH secreting tumour - Isotope scanning
- scan thyroid gland looking at iodine uptake
- hot nodules - likely benign
- cold nodules - possibly malignant
How is T1DM investigated?
T1DM Ix include:
1. Plasma glucose >11.1mol/L
- C-peptide and diabetes specific antibodies (often done to confirm diagnosis)
- not routine - atypical features, suspected monogenic form and uncertain of classification
How us T2DM investigated?
- HbA1c levels = >persistent hyperglycaemia over 48mmol/mol
- Random glucose >11.1mmol/L
- Fasting glucose >7mmol/L
if symptomatic = can use single abnormal HbA1c/fasting glucose - but usually repeat is preferred
if asymptomatic = arrange repeat testing inital test show abnormal reading indicative of diabetes
- OGTT
- used to screen pt who have a high fasting glucose but not enough to meet diabetes criterion
- also used in screening of gestational diabetes and dx of Acromegaly
What are contraindications of HbA1c tests?
- acute illness
- pregnant or 2/12 postpartum
- Pancreatic injury/surgery
- under 18yrs
- HIV
- on meds that increase glucose
- 2/12 or less hx of diabetes
What is macrocytic anaemia investigated?
how is it investigated?
what mx plans involve?
low Hb and high MCV
investigated - vitB12 and folate levels (?deficient)
VitB12 Def = IM hydroxycobalamin TDS 2/52 + every 3/12
Folate Def = oral supplementation of folic acid
What is synacthen test used for?
To diagnose adrenal insufficiency aka Addison’s
Measure serum cortisol (30mins)
administer IM/IV tetracostactide - measure cortisol after
Normal ppl = cortisol increases to 500-550 after 30-60mins
adrenal insufficiency = no cortisol increase
what is fine needle-aspiration of a thyroid nodule?
in thyroid nodules - request thyroid US and FNA biopsy
U1-5 to classify the nodules
anything with U3-5 = FNA needed
FNA - diagnosis/staging
limitations of FNA?
- false negatives - more in nodules really large(>4cm)/small(<1cm)
- Suspicious FNA - not able to distinguish between benign and malignant
- Non-diagnostic results = DON’T ASSUME BENIGN
Investigations for hyperparathyroid disorders?
- high serum Ca2+,
- Low phosphate
- PTH raised or normal
- technetium-MIBI subtraction scan
- pepperpot skull on X-ray and generalised osteomalacia
Investigations for hypoparathyroid disorders?
- low calcium
- high phosphate
- low PTH
ECG will show Prolonged PR interval
What are the stages of hyperkalaemia?
- mild: 5.5 - 5.9 mmol/L
- moderate: 6.0 - 6.4 mmol/L
- severe:≥ 6.5 mmol/L
What ECG changes are seen in hyperkalaemia?
Peaked/tall-tented T waves, loss/flattening of p waves,
broad QRS, sinosoidal wave pattern
What are ECG signs for hypokalaemia?
- U waves
- small/absent T waves
- prolonged PR
- ST depression
- Long QT
Investigations for Diabetes Insipidus?
water deprivation test
- high plasma osmolality and low urine osmolality
- cannot retain water, urine osmolality >700mOsm/kg - exlcude DI
Investigations in SIADH?
- U&Es - hyponatremia
- urine sodium & osmolality with be high
What investigation is done in phaeochromocytoma?
24hr urine collection of catecholamines and metanephrines
Prolactinoma Ix?
- prolactin levels (raised)
- clinical signs - bitemporal hemianopia, hypopituitarism
- diagnostic - test - MRI
Investigations in Acromegaly?
IGF-1 Levels done intially - if raised then do OGTT
OGTT will confirm diagnosis and thus is the diagnostic test
Investigations done in suspected Diabetic Ketoacidosis (DKA)?
fingerprick BM >11.1mmol/L
high ketone levels
- 2+ in urine
- >3mmol/L in blood
identify causes - blood tests to check for infection
- CRP
- WCC
as well as CXR and urine dip
Investigations and findings in HSS?
often precipitated from infection/dehydration
- typcially blood glucose >30mmol/L
- absent signs of ketosis - not ketones in blood or urine
Low TSH, raised T3/4
overt hyperthyroidism
Low TSH and normal T3/4
subclinical hyperthyroidism
The specific Ix done in Grave’s disease?
TSH-receptor antibodies (TRAbs)
