Masterclasses Flashcards
Fast-acting insulin
Soluble human (peak 2-4hrs) - humulin s, actrapid
Short-acting analogue (peak 1hr) - novorapid (aspart), humalog (lispro)
Take before meals/ snacks
Intermediate acting and pre-mixed insulin
isophane (NPH, peak 6-10hrs) - insulatard, humulin I
Control overnight/ between meals
Pre-mixed (cloudy, biphasic) - humulin M3, novomix 30
Long acting insulin
Lantus (glargine), levemir (detemir)
Peak 5 hours, last <24hours
Control overnight/ between meals
Multiple daily dose injection/ basal-bolus
Pre-meal short-acting x3 (1u per 10g carbs)
Isophane/ long-acting x1-2
0.5-0.75u/kg body weight (50% long, 50% short)
DAFNE programme
Biphasic/ twice daily regimen
Combination of short-acting and intermediate e.g., novomix 30
More in type 2
0.5-0.75u/kg body weight (66% morning, 33% evening)
Once daily long acting insulin
Type 2
Bedtime dose of long-acting combined with other oral hypoglycaemic agents
Titrated against fasting blood glucose (6)
Oral hypoglycaemic agents
Biguanides - metformin
Sulphonylureas - glimepiride
DPP-4 inhibitors - sitagliptin
Alpha-glucosidase inhibitors - acarbose
Thiazolidinediones - pioglitazone
GLP-1 analogue - exenatide
Continuous SC insulin infusion
1/1000 type 1 (>12yrs, poor control)
Continuous delivery
Diabetic Ketoacidosis definition
an extreme metabolic state caused by insulin deficiency. breakdown of fatty acids (lipolysis) produces ketones (ketogenesis) which are acidic. exceeds the body’s buffering capacity.
DKA treatment
Fluid replacement
1L 0.9% NaCl in 1st hour if systolic >90
1L 0.9% NaCl + 40mmol KCL (if <5.5) over next 2 hours, 2 hours, 4 hours etc.
Fixed rate IV insulin infusion
0.1u/kg/hr of human soluble insulin (actrapid or humulin s) made up to 50ml with 0.9% NaCl
Continue long acting as normal
Add 10% glucose 125ml/hr if blood glucose falls <14 mmol/L
Diabetic advice
Diabetic nurse support
Follow-up with endocrine/ diabetes
Insulin training
Drugs to avoid in children
Tetracyclines: discolouration and pitting of tooth enaeml
Aspirin: reye’s syndrome
SSRI: suicidal ideation
Codeine: respiratory depression in CYP2D6 ultrarapid metabolisers (to morphine)
Dosing in children
Dose based on age, weight, body surface area
Round sensibly (never over the maximum)
Resus fluids in kids
10ml/kg of glucose free sodium containing fluid (131-154mmol/L) over <10mins
E.g., 0.9% NaCl or Hartmann’s
10-20ml/kg if renal impairment, HF, neonates
Fluid maintanence in kids
4ml/kg/hr for first 10kg (or 100ml/kg/day)
2ml/kg/hr for next 10kg (or 50ml/kg/day)
1 ml/kg/hr for every kg over 20kg (or 20ml/kg/day)
E.g., 0.9% NaCl or Hartmann’s
Don’t give glucose without sodium (risk of hyponatraemia)
Body surface area
cBNF conversion table to aid drug calculations
Also, table for mean weight based on age
Drug principles in pregnancy
Avoid any in first trimester
Lowest clinically effective dose
Avoid polypharmacy
Drugs with proven safety record
‘Safe’ drugs in pregnancy
paracetamol
b-lactam Abx
steroids
bronchodilators
Teratogenic drugs A-N
ACE inhibitors - renal abnormalities, IUGR, PDA
Atenolol - low BW
Carbimazole - neonatal hypothyroidism (in 1st trimester)
Lithium - Ebstein’s
Methotrexate - termination
NSAIDs - premature PDA closure, oligohydramnios, persistent pulm HTN
Teratogenic drugs P-W
Phenytoin - craniofacial, growth, mental
Quinolones
Retinoids - CNS, renal, ear, eye, parathyroid
Sodium valproate - NTD
Statins
Tetracycline - tooth discolouration
Warfarin - fetal warfarin syndrome, neonatal/ placental haemorrhage
Epilepsy in pregnancy
Preference for lamotrigine
Avoid SV if childbearing age
5mg folic acid if on antiepileptics
Vitamin D in pregnancy
All pregnant/ BF should receive 10micrograms (400units) daily
Cholecalciferol or ergocalciferol
1000units if high risk (obese, dark skin, little sun)
Avoid in BF A-C
Amiodarone - neonatal hypothyroidism
Aspirin - theoretical risk of Reye’s
Barbiturates - drowsiness
Benzos - Lethargy
Carbimazole - hypothyroidsim
Codeine - opiate OD
Avoid in BF
COCP - diminish milk supply
Cytotoxic drugs - IS, neutropenia
Dopamine agonists - suppress lactation, present in milk
Ephedrine - irritable
Tetracyclines - tooth discolouration
Adrenaline
1 in 1000 = 1g adrenaline in 1000ml so 1mg in 1ml
Aminophylline
If previously treated with theophylline then already distributed so don’t need the loading dose
Straight to IV infusion
Overweight/ underweight child
If overweight then prescribe using ideal weight
If underweight then prescribe using actual weight
Toxidromes
‘clinical fingerprint’, characterised by a classic constellation of symptoms and signs due to toxic effects of a drug
Common toxidromes
Anticholinergic - antihistamine, TCAs, anti-psychotics, atropine
Cholinergic - organophosphates, mushrooms, insecticides
Sympathomimetic - amphetamines, cocaine, salbbutamol
Sedative-hypnotic - opioids, benzos, ethanol, anticonvulsants
Opioid - morphine, heroin, oxycodone, codeine
Antidotes
Opiate - naloxone
Benzo - flumazenil (only if resp dep requiring mechanical) SE: seizure threshold
Salicylates - sodium bicarb (alk urine)
TCA - sodium bicarb
Paracetamol - acetylcysteine
Digoxin - digibind
Insulin/ betablockers - glucagon
Iron salts - desferrioxamine mesilate
Methanol, ethylene glycol - fomepizole
Warfarin - vit K1
SSRI/ ethanol - none
Alcohol dependence
Local guidelines for withdrawal prescribing in inpatients
Regular chlordiazepoxide (diff prescription for diff doses)
? pabrinex 1 + 2 (pair, two vials), after this has ended start thiamine + multivitamin
Paracetamol OD guidelines
<8hrs after ingestion
- consider charcoal if <1 hr ago
- measure plasma level after 4hours
Revised treatment nomogram (treat above line), use 110kg max if obese
8-24hrs
- urgent plasma level
- treat now if expect >150mg/kg or liver injury
- stop when asymp + normal LFTs/ creatinine and INR
> 24hrs
- treat if jaundice/ hep tenderness
- treat if ^ALT, INR>1.3, para conc detectable
- repeat bloods 8-16hrs, other causes?
Paracetamol OD staggered
treat ALL patients
bloods 4 hours after last dose
Paracetamol monitoring
4 hours to deplete glutathione levels - why you can’t test before
Acetylcysteine anaphylactoid
Not a contraindication to treatment
Management - temp stop and restart at lower rate, anti-histamines, neb salbutamol
Aspirin OD management
regular plasma levels
correct hypokalaemia from met acidosis
resp support
If plasma conc >500mg/l (350 in kids)
Sodium bicarbonate IV
^serum and urinary PH so v transfer into CNS and ^renal excretion
IV fluids (crystalloid + glucose)
> 700 consider haemodialysis
Aspirin OD monitoring
Sodium and potassium 1-2hourly
Hourly urine pH
Critical Medications
Systemic corticosteroids
Anti-epileptics
Anti-parkinsons
Insulin
Anticoagulants
All emergency drugs
Anti-epileptics (can’t swallow)
Discuss with pharmacy
Consider early placement of NG as liquid/ dispersible preps not available for levetiracetam, topiramate and lamotrigine
Older ones can be IV/ rectal
Parkinsons (can’t swallow)
Dispersible or NG or swap to rotigotine patch (convert from l-dopa, benefit >risk)
Talk to pharmacy/ senior
Anticholinergic burden
- Tolterodine, oxybutynin, promethazine, amitriptyline, solifenacin
2 - cetirizine, sertraline, prochlorperazine
Intracellular space and extracellular space
Intracellular space (2/3 total body fluid)
Extracellular space (1/3) - intravascular (20%), interstitial (80%), third
What is third space? Examples?
Areas of the body that don’t normally contain fluid
Peritoneal, pleural, pericardial, joints (also interstitial oedema)
Fluid intake and output
Intake - PO, nasogastric/ PEG, IV, TPN
Output - urine, bowel, stoma, vomit, NG, stomach aspiration, bile drain, bleeding, sweating, fistula, hyperventilation
Insensible is difficult to measure (breath, burns, sweat)
Hypovolemia presentation
Reduced extracellular volume
BP <100, HR >90, cap refill, cold peripheries, ^RR, dry membranes, v turgor, v urine output, sunken eyes, weight loss, polydipsia
In third spacing may also have signs of overload
Crystalloid
Small particles in solution that readily diffuse
E.g., 0.9% NaCl, 5% dextrose, 0.18% NaCl in 4% glucose, Hartmann’s
+ resus, vomiting
- hyperchloraemic met acidosis (saline)
0.9% NaCl, 5% dextrose, Hartmann’s
0.9% NaCl - 1L water with 154mmol of each (SE: ^Na, ^Cl met acidosis)
5% dextrose - 1L water with 50g glucose, no electrolytes (SE: v Na, oedema)
Hartmann’s - 1L water with sodium, chloride, potassium, calcium and lactate buffer (v risk of acidosis)
Colloids
Larger molecules, stay in intravascular space as can’t cross membrane
E.g., human albumin solution (^ oncotic pressure of plasma)
Tonicity (Hypotonic, Isotonic, Hypertonic)
Osmotic pressure gradient between two fluids across a membrane, determines whether water moves by osmosis
Hypotonic = 5% dextrose in 0.18% NaCl (not for resus, SE: dilutional v Na)
Isotonic = 0.9% NaCl, Hartmann’s, plasma-lyte
Hypertonic = 3% saline (conc. solutes > than in plasma)
Resuscitation Fluids
Stat 500ml isotonic fluid bolus <15mins (stat), Repeat 250-500ml boluses if required
Expert help if not responding after 2L
Bolus should have 130-154mmol/L sodium
**Do not give over 10mmol/hour of potassium
Fluid Maintenance
Indication - NBM, bowel obstruction
Stop IV as soon as oral good enough
25–30 ml/kg/day water
1 mmol/kg/day sodium, potassium and chloride
50–100 g/day of glucose (prevent ketosis, not nutritional)
Ideal body weight not BMI
E.g., 25-30 ml/kg/day 0.18% sodium chloride in 4% glucose with 27 mmol/l added potassium (SE: v Na)
Alternative formula for maintenance
Adult = 1.5ml/kg/hr
Fluid maintenance – monitoring
Daily (at least)
= Fluid status, fluid balance chart and U&Es
Max 24hrs of fluids prescribed at one time
SE: dilution of Na (with hypotonic solutions), K, Ca, Mg, haemoglobin and haematocrit (anaemia), clotting factors, platelets and fibrinogen causing coagulopathy
Consider less fluid if
Elderly, renal impairment, HF, malnourished/ risk of refeeding
Consider 20-25ml/kg/day
(250ml for resus)
Slower bags for maintenance
Replacement and redistribution
Issues with electrolyte and fluid replacement/ distribution
Maintenance +/- losses and gains
Include input from IV Abx etc
Potassium replacement
Estimation of deficit
(K normal - K measured) x kg x 0.4
Give this in addition to daily requirement
Maintenance Fluids: Caution
Avoid dextrose if head injury/ stroke - worsens cerebral oedema (hypotonic)
Avoid normal saline in liver disease - worsens ascites (use Hartmann’s)
Hypercalcaemia: Management
Rehydration with normal saline e.g., 4+ litres/day
Following rehydration bisphosphonates may be used. They typically take 2-3 days to work with maximal effect being seen at 7 days
