Doses that decide questions

Resuscitation

• Adult cardiac arrest: adrenaline 1 mg IV every second cycle; amiodarone 300 mg after the third shock for VF or pulseless VT.
• Adenosine: 6 mg, then 12 mg, then 12 mg, as a rapid push with a flush.
• Atropine: 600 microgram IV, repeated to a maximum of 3 mg.
• Newborn resuscitation: adrenaline 10 to 30 microgram/kg IV.
• Trauma: tranexamic acid 1 g over 10 minutes, then 1 g over 8 hours, within 3 hours of injury.
• Burns: modified Parkland, 3 mL x kg x percent burn, half in the first 8 hours from the time of injury.

Anaphylaxis

• IM adrenaline: 0.01 mg/kg of 1:1000, maximum 0.5 mg, into the outer mid-thigh; repeat every 5 minutes as needed.
• Autoinjectors: 150 microgram for 7.5 to 20 kg; 300 microgram over 20 kg; 500 or 300 microgram over 50 kg.
• Observe at least 4 hours after the last dose of adrenaline.

Metabolic emergencies

• Hyperkalaemia with ECG changes: calcium gluconate 10%, 10 mL IV; then insulin 10 units with 50 mL of 50% glucose.
• Hypoglycaemia (below 4 mmol/L): 15 g of fast carbohydrate, recheck at 15 minutes.
• DKA: fixed-rate insulin about 0.1 units/kg/hour; hold insulin if potassium is below 3.5 mmol/L.
• Adrenal crisis: IV hydrocortisone 100 mg immediately.
• Severe symptomatic hyponatraemia: 3% saline, aiming for a rise of about 5 mmol/L; no more than 8 to 10 mmol/L in 24 hours.

Seizures

• Child, at 5 minutes: midazolam 0.3 mg/kg buccal or intranasal (maximum 10 mg), or 0.2 mg/kg IM.
• Second line: levetiracetam 60 mg/kg IV or phenytoin 20 mg/kg IV.

Poisoning

• Poisons Information Centre: 13 11 26.
• Paracetamol: acetylcysteine 200 mg/kg over 4 hours, then 100 mg/kg over 16 hours. The nomogram line starts at 150 mg/L at 4 hours.
• Tricyclics: sodium bicarbonate when the QRS is wider than about 100 ms.
• Organophosphates: double the atropine dose every 5 minutes until the chest is dry.
• Iron: more than 60 mg/kg of elemental iron is potentially toxic.

Heart, brain and blood

• ACS: aspirin 300 mg chewed; ticagrelor 180 mg or prasugrel 60 mg before angiography; clopidogrel 300 to 600 mg with fibrinolysis or an oral anticoagulant.
• Stroke thrombolysis: tenecteplase 0.25 mg/kg (maximum 25 mg) or alteplase 0.9 mg/kg (maximum 90 mg).
• Life-threatening warfarin bleeding: four-factor prothrombin complex concentrate 50 IU/kg with IV vitamin K 5 to 10 mg.

Lungs

• Acute asthma: prednisolone 37.5 to 50 mg daily for 5 to 10 days, no taper.
• Child salbutamol by spacer: 6 puffs under 6 years, 12 puffs from 6 years.
• COPD exacerbation: prednisolone 30 to 50 mg for 5 days, with amoxicillin or doxycycline for 5 days.
• Croup: dexamethasone 0.15 mg/kg, or 0.6 mg/kg if severe.

Infection

• Sepsis, source unknown: gentamicin 4 to 5 mg/kg plus flucloxacillin 2 g IV, within 60 minutes.
• Cystitis in women: trimethoprim 300 mg for 3 days.
• Chlamydia: doxycycline 100 mg twice daily for 7 days; azithromycin 1 g in pregnancy.
• Gonorrhoea: ceftriaxone 500 mg IM plus azithromycin 1 g (2 g for throat infection).
• Early syphilis: benzathine benzylpenicillin 1.8 g IM once.
• PID: ceftriaxone 500 mg once, then doxycycline 100 mg and metronidazole 400 mg, both twice daily for 14 days.
• H. pylori: a PPI, amoxicillin 1 g and clarithromycin 500 mg, all twice daily for 14 days.
• C. difficile: oral vancomycin 125 mg four times daily for 10 days.
• Septic arthritis (adult): flucloxacillin 2 g IV 6-hourly.
• Open fracture: cefazolin 2 g IV 8-hourly, ideally within 3 hours of injury.
• Rheumatic fever prophylaxis: benzathine benzylpenicillin every 28 days.

Pregnancy and birth

• Folic acid 400 microgram daily (5 mg if high risk); iodine 150 microgram.
• Aspirin 150 mg at night, started before 16 weeks, stopped from 34 weeks, to prevent pre-eclampsia.
• Anti-D: 625 IU at 28 and 34 weeks; 250 IU after a first trimester miscarriage, ectopic or termination from 10 weeks.
• Magnesium sulfate: 4 g IV, then 1 g an hour for 24 hours; the antidote is calcium gluconate.
• Third stage: oxytocin 10 IU IM.
• PPH: oxytocin 5 IU slow IV; ergometrine 0.25 mg; carboprost 0.25 mg IM, up to 8 doses; misoprostol up to 1000 microgram; tranexamic acid 1 g IV.
• Newborn: vitamin K 1 mg IM.

Joints and steroids

• Gout flare: colchicine 1 mg, then 0.5 mg an hour later.
• Polymyalgia rheumatica: prednisolone about 15 mg daily.
• GCA without visual symptoms: prednisolone 40 to 60 mg daily, started the same day.

Alcohol and palliative care

• Thiamine: 300 mg a day to prevent Wernicke encephalopathy; at least 500 mg a day to treat it.
• Breakthrough opioid: one-twelfth to one-sixth of the 24-hour dose.
• Subcutaneous morphine: one-third to one-half of the oral dose.
• A laxative with every regular opioid.