Endocrine Flashcards
Congenital Adrenal Hyperplasia
- 21-hydroxylase deficiency in the adrenal cortex
- autosomal recessive inheritance
- incidence of 1: 15,000 births
- marked overproduction of cortisol precursors and adrenal androgens
- hypoaldosteronism and salt loss only in severe forms
Clinical features
- ambiguous genitalia at birth in F
- no changes to the internal female organs
*boys have minimal features
-subtle hyperpigmentation
-slight penile enlargement
*boys with the salt-losing form
-present at 7-14 days of life
-adrenal crisis
*boys with the non-salt-losing form
-present with early virilisation at age 2-4 years
Non classic form
*mild non-classic form is a common cause of hyperandrogenism
*do not have cortisol deficiency
Mx
- Treat symptomatic pts
- Glucocorticoids
- Mineralocorticoids
- NaCl for salt losing forms
DKA Fluid Mx
- Fluid resuscitation - IV bolus 10-20ml/kg
- Correct dehydration
- Calculate deficit + maintenance reqruiements
- Replace over 48hrs
- Subtract any bolus from the total
- K+ rpelacement if <5.5 and passing urine
- Seek and treat electrolyte abnormalities
- K, Na, PO4, Mg
- Reverse Ketoacidosis
- Actrapid 0.05-0.1u/kg/hr
- Add dextrose when BSL drops > 5mmol/hr or BSL < 15mmol/l
- Monitor for complications
- Cerebral odema
- Hypogylcaemia
- Electrlolyte AbN
- Aspiration
Cerebral oedema
Some degree of subclinical brain swelling is present during most episodes of DKA
Clinical cerebral oedema occurs suddenly, usually between 6-12 hours after starting therapy (range 2-24 hours)
Mortality and severe morbidity rates are very high without early treatment
If cerebral oedema is suspected, this should be immediately discussed with a consultant
Risk Factors
First presentation diabetes
Long history of poor control
Age <5 years old
Signs
Early: Headache, irritability, lethargy, vomiting
Later: depressed consciousness, incontinence, thermal instability
Very late: bradycardia, increased BP, respiratory impairment
Treatment
Nurse head up
Reduce fluid infusion rate by 1/3
Mannitol 20% (0.2 g/mL) dose: 0.5 g/kg IV over 20 minutes (dose range: 0.25-1 g/kg), repeat if no improvement within 30-60mins.
CT if stable
Discuss with consultant / retrieval
Critical Hypoglycaemia causes
BSL < 2.6 mmol/l
Critical Hypoglycaemia Bloods
BSL < 2.6 mmol/l
UECs
LFTs
Hormones - Insulin, C-peptide, GH, Cortisol
Biochem - Glucose, Ketones, FFA, Lactate, Ammonia, Amino Acids, Carnitine
Hypoglycaemia Rx options
BSL < 2.6 mmol/l
Awake: PO feed (EBM, juice), glucose gel
Dec LOC: IM glucagon or IV dextrose 10% 2mls
Glucagon:
Neonates 0.03-0.1mg/kg
< 25kg 0.5U
>25kg 1.0 unit
Aim:
* Warm – Hypothermia => inc metabolism + hypoxia => worsening hypoglycaemia
* Pink – Hypoglycaemia => dec surfactant + pulm vasoconstriction => hypoxia => inc WOB => worsening hypoglycaemia
* Sweet – Maintaining normoglycaemia
* Calm – minimising energy use and stress, both of which significantly impact the above systems
