Endocrinology Flashcards
What causes t1 diabetes
autoimmune destruction of beta cells of the islets of langerhans in the pancreas causing reduced/ no insulin production
Insulin autoantibodies can be detected in genetically predisposed individuals from 6-12 months
how does t1 diabetes present
- polyurea
- polydipsia
- weight loss
- lethargy
- frequent UTIs
- may present in DKA: reduced GCS, vomiting, hyperventilation, dehydration
How should suspected T1 diabetes be investigated and what are the criteria for diagnosis
- Random blood glucose >11 or fasting >7 + symptoms
- Two fasting glucose >7
- Hba1c > 48/ 6.5%
- Venous blood glucose >11 two hrs after a 75g glucose (oral glucose tolerance test)
- Albumin: creatinine ratio
- TFTs
- Full lipid profile
- U&Es and eGFR
What lifestyle advice is given to those with t1 diabetes
- Regular physical activity is important
- Smoking cessation
- Medical emergency ID bracelet
- Dietary advice (++ fruit and veg, low gi foods, dietician rv) and carb counting training
- DESMOND course
- always have chips after a night out to prevent hypo
How is insulin therapy managed in t1 diabetes
- Multiple daily injection basal–bolus insulin regimens: injections of short‑acting insulin or rapid‑acting insulin analogue before meals, together with 1 or more separate daily injections of intermediate‑acting insulin or long‑acting insulin analogue. Offer pump therapy if this is not appropriate
- Training relatives on glucagon usage and educate on hypos
- Give rapid acting insulin analogues for use during intercurrent illness or hypers- educate about sick day rules
How are pts with T1 diabetes monitored (9)
- clinic appts 4 times a year
- regular dental checks
- eye exam every 2 yrs
- real time continious monitoring if severe frequent hypos, high levels of physical activity or unable to communicate symptoms of hypos
- thyroid disease screen yrly
- ACR from first urine sample of day for CKD from age 12
- HTN yrly from age 12
- BMI monitoring
- injection sites
What targets are given to those with T1 diabetes with regard to glucose and Hba1c levels?
- BM of 4-7 on waking and before meals
- BM of 5-9 after meals
- at least 5 when driving
- Hba1c <6.5%
- measure at least 5 times a day before meals
What causes hypos in t1 diabetes
- alcohol
- exercise
- too much insulin
- missing meals
- illness
How should mild- moderate hypos (bm<3.9, conscious) be managed?
- 10-20g glucose by mouth (2-4 spoons of sugar in water// 200ml glucojuice)
- recheck in 15 mins and repeat if persists
- give complex carb eg toast
How should severe hypos be managed in hospital and in community?
hospital: 10% glucose IV up to 500mg/ kg
community: 1mg IM glucagon if >25kg or 8yrs, 0.5mg if <25kg or 8yrs. if symptoms persist for >10 mins get assistance. Give complex carb when normoglycaemic
Other than hypos, give 7 complications of t1 diabetes
- juvenile cateracts
- DKA
- necrobiosis lipodica
- addisons (schmidt syndrome)
- CKD
- diabetic retinopathy
- diabetic neuropathy
- CVD
How is juvenile cataracts managed?
- lens replacement surgery same as in adults
- it is rare and other causes eg rubella, measles, chicken pox, herpes and metabolic disorders need to be excluded
What is necrobiosis lipoidica?
- Irregularly shaped callous lesions with reddish- brown pigmentation and central atrophy
- Caused by collagen degeneration with granulomatous response associated with thickened blood vessels and fat deposition
- Pretibial is commonest, face, scalp, trunk and upper arms are also common
- Often not painful due to neuropathy but can be very painful
How is necrobiosis lipoidica managed?
- very hard to managed
- avoid trauma to prevent ulcers
- good wound care
- steroids
- immunomodulatory drugs
- phototherapy
- aspirin
- excision
What is schmidts syndrome and how does it present
- Addisons + t1 diabetes= Schmidt syndrome
- CFs: muscle weakness/ pain, hyperpigmentation of skin, fatigue, mood irregularity, salt craving, postural hypotension, weight loss, nausea and/ or diarrhoea, abdo pain
How should DKA be managed (if unwell/ vomiting/ dehydrated/ not alert)?
- ABCDE and 2x large bore cannula
- 10ml/kg NS over 1 hr (if BP <90mmHg give 20ml/kg over 15 mins, then reassess, call ITU if still low after 2nd bolus)
- add 50 units human actrapid to 50ml NS and start fixed rate infusion at 0.1 units/ hr/kg (0.5 if age<5) and continue until resumes normal insulin regime
- monitor closely, aim for drop of 3mmol/L/hr glucose and increase insulin if needed- check VGB at 2, 4, 8, 12 and 24 hrs
- give next L fluid over 2 hrs, next over 4 and next over 12 until fluid replaced - aim to replace fluid over 48hrs
- K+ will start moving back into cells so add 40mmol K+/ L bag to subsequent bags
- when glucose is <14 start 10% dextrose at 125ml/hr alongside saline to avoid hypos, if ketones <3 reduce insulin to 0.05unit/kg/hr
- if glucose ever <6, DONT STOP INSULIN IF KETONES still<1- increase dextrose
- continue with fixed rate infusion until ketones <1 and ph >7.3 and drinking normally then start SC insulin and stop infusion 30 mins after
- Hourly BMs, fluid balance and neuro obs (worry about cerebral odema), U&Es 2 hrly then 4 hrly, ketones 1-2 hrly
- find and treat cause
What may cause congenital hypothyroidism
- insufficient iodine intake in pregnancy
- levothyroxine intake in pregnancy
- defect/ aplasia of thyroid gland
- 30% resolve by age 3 but most need replacement throughout life
What may cause acquired hypothyroidism in children
- hasimotos
- lack of iodine
- radiation
- lithium
- infiltrative disease
How does hypothryoidism present in children?
- CFs similar to adults: fatigue, constipation, coarse dry hair, weight gain
- CFs only in children: slow growth, delayed puberty, delayed tooth development, goitre
What is screened for antenatally?
- sickle cell and thalasssemia early (blood test)
- downs (screening blood test and USS at 12/13 weeks)
- other abnormalities eg cardiac, limb, GI at detailed 20 week scan
- infectious diseases in mother (HIV, syphilis, Hep B, rubella)
- preeclampsia, diabetes and placenta previa screening also
Describe what is involved in a newborn and infant physical examination (NIPE)
- EYES: mainly looking for cateracts and retinoblastoma
- HEART: for congenital disease
- HIPS: for congenital dysplasia of the hips
- TESTIS: for cryptochidism
- GENERAL APPEARANCE: for downs etc
Describe the difference between a significant and a benign murmur
Significant: loud, over wide area, harsh tone, other abnormal findings
Benign: soft, short, systolic, localised to one area (usually L sternal edge), no added sounds or abnormalities
What finding suggests a newborn has a cateracts
- absent red reflex
- white red reflex suggests retinoblastoma
What is screened for on the newborn heel prick test? (10)
- congenital hypothyroidism
- CF
- PKU
- Sickle cell
- MCADD
- isovaleric acidaemia
- glutaric aciduria type 1
- homocystineuria
- maplesyup urine disease
- B thalassaemia major
What level of TSH is diagnostic for hypothyroidism?
<8. If its >8 repeat twice and if mean is <8 then its diagnostic. If <20 refer for suspected CHT.
How may congenital hypothyroidism present other than with blood tests?
May present with prolonged jaundice, constipation and feeding problems/ failure to thrive but usually asymptomatic due to maternal T4 and small amounts of functioning thyroid tissue. Leads to intellectual impairment if untreated
How is cystic fibrosis diagnosed? (describe test)
- raised immunoreactive trypsin (IRT) on blood spot, meconium ileus or prolonged jaundice
- then sweat test or CTFR gene mutation identification
- pilocarpine is used to induce sweat, mild electrical current pushes medicine into skin, pad collects sweat, need >100mcg of sweat to diagnose
What is MCADD and how is it managed?
Inability to utilise fat stores, leads to encephalopathy rapidly after fasting. Manage by avoid fasting + emergency regime
How is maple syrup urine disease managed?
- low protein diet
How and when is hearing tested
Within first 5 weeks, using automated optoacoustic emission. Its repeated twice if they fail first. This helps pick up hearing disorder that otherwise present with developmental delay
What signals the start of puberty
- increase in frequency and amplitude of GnRH, leading to LH and FSH release, causing testosterone/ estradiol release
Describe the sequence of changes in puberty for females
- starts between age 8-14
- breast bud development is first sign
- pubic and axillary hair growth is sign of adrenal androgen secretion
- menarche usually occurs 2-3 yrs after the start of breast development
- growth spurt occurs earlier than in boys
Describe the sequence of changes in puberty for males
- starts between 9 and 14
- testicular enlargement is first sign- dependant on FSH release
- progressive signs of androgen excess: penile enlargement, pubic hair growth
- later signs of puberty inc growth spurt, voice deepening, facial hair growth
- growth starts with hands and feet and move proximally to finish with te trunk
What clinical features indicate precocious pseudopuberty? What can cause this
- signs of androgen excess (penile enlargement, hair growth) before testicular enlargement/ breast bud development
- suggests androgens from different source eg congenital adrenal hyperplasia, adrenal tumours, cushings, testicular tumours)
Define delayed puberty for boys and girls
- absence of testicular development (volume <4ml) by age 14 for males
- absence of breast development by 13 yrs or primary amenorrhoea with normal breast development by age 15
- most simply have constitutional delay in growth and puberty (GDGP) and need no investigation
Other than constitutional delay, list 5 central causes of delayed puberty?
w/ Intact HPA: - chronic illness - malnutrition - excess physcial activity - steroids - hypothyroidism - psychosocial deprivation Impaired HPA: - tumours near HPA - congenital anomalies - irradiation treatment - trauma (head or surg) - isolated hypogonadotrophic hypogonadism
What is isolated hypogonadotrophic hypogonadism?
- low gonadotrophins and sex steroid levels in absences of other anomalies in the HPA- gonadal system
- other associated features inc cyptorchidsm, micropenis, cleft lip/ palate, dental agenesis, skeletal abnormalities, hair loss
Give 3 peripheral causes of delayed puberty in boys and girls
Male:
- bilateral testicular damage (cyptorchidism, atresia, torsion etc)
- gonadal dysgenesis
- irradiation to testis
- drugs like cyclophosphamide
Females:
- gonadal dysgenesis: turners, prader willi
- irradiation
- drugs
- intersex disorders : AIS, congenital adrenal hyperplasia
- PCOS
How should delayed puberty be assessed?
- History: growth pattern (CDGP usually has long standing short stature), general health, gonadal impairment, family patterns, psycosocial problems, sports
- Exam: height, weight, pubertal staging, dysmorphic features, fundoscopy, eye feilds (pituitary tumour), signs of chronic disease (eg clubbing, anaemia)
What investigations can be ordered for delayed puberty (if any indicated)
- Basal FSH, LH, serum estadiol/ testosterone: LH and FSH low in CDGP or hypogonadotrophic hypogonadism and elevated in gonadal failure
- prolactin and IGF1 (low in GH deficiency)
- GnRH and growth hormone tests
- karyotyping if ?chromosomal abnromality
- FBC, ferritin, U&E, coeliac screen
- Pelvic USS if female
- wrist x ray for bone age: delayed in CDGP, GH deficiency and hypothyroid
- rarely MRI or CT head for pituitary disorders
How is CDGP managed?
- short courses sex hormones may be used to help them catch up with peers. Testosterone for 3-6 months can be used to induce puberty in boys. Girls get gradually increasing doses of oestrogen with cyclical progesterone therapy once adequate oestrogen levels achieved
How is primary testicular and ovarian failure managed?
- induction followed by ongoing hormone replacement therapy
- regular injections of testosterone for boys
- girls get gradually increasing oestrogen doses to avoid premature fusion of epiphyses then cyclical progesterone then low dose COCP
Define precocious puberty for boys and girls
Puberty development before age 8 in girls and 9 in boys. Usually benign in females but rarely idiopathic in boys.
What causes gonadotrophin dependant (or central) precocious puberty?
- no cause found in 80% girls and 40% boys
- Tumours: gliomas, astrocytomas, hCG secreting germ cell tumours)
- CNS trauma or infections
- hamatomas or hypothalamus
- hydrocephalus or arachnoid cysts
What causes gonadotrophic independant precocious puberty (high testosterone/ oestrogen with low LH, FSH, GnRH)
- congenital adrenal hyperplasia
- HCG secreting tumours
- ovarian/ testicular tumours
- mcCune- albright syndrome
- silver russel syndrome
- Testotoxicosis: familaial syndrome with rapid growth, skeletal maturation and sexually aggressive behaviour in first 2-3 yrs of life (v v rare)
What is non progressive precocious puberty?
Following signs of early puberty, the situation stabilises or regresses and continues at correct time
What is isolated precocious pubarche, isolated precocious menarche and isolated precocious thelarche?
Pubarche: early pubic hair development without other features of puberty, may be present in boys or girls age <7 due to adrenal androgen secretion in middle of childhood
Thelarche: early breast bud development without other features may occur in those <3 and spontaneously regresses.
Menarche: isolated early vaginal bleeding in absence of other causes or features
What investigations may be done for precocious puberty?
- sex steroid levels
- LH and FSH (distinguish between gonadotrophin dependant and independant)
- GnRH
- TFTs
- adrenal steroid precursors if suspect congenital adrenal hyperplasia
- HCG if ? testicular tumour
- pelvic USS if gonadotrophin independant PP to detect ovarian cysts or tumours
- testicular USS if ? tumour
- MRI if ? adrenal tumour
- wrist x ray for bone age
How is precocious puberty managed?
- puberty can be arrested and GH given for CPP if height prognosis is poor, otherwise its left
- surgery to remove tumours
- GnRH agonists for gonadotrophin depenant causes (they overstimulate pituitary and cause desensitisation, so less LH and FSH produced.
Describe the signs, symptoms and biochemical abnormalities of DKA
Signs: dehydrated, hyperventilation, smell of ketones, lethargic, drowsy, reduced GCS
Symptoms: polydipsia, polyuria, weight loss, enuresis, tiredness, vomiting, confusion, abdo pain
BIOCHEM:
- glucose >11 (not always)
- pH >7.3 or bicarb >15 (mod= 7.1-2, severe= <7.1)
- Ketones in blood <3
