Please note OSCEstop content is for educational purposes only and not intended to inform clinical practice. OSCEstop and authors take no responsibility for errors or the use of any information displayed.Drugs and doses are intended for non-pregnant adults, who are not breastfeeding, with normal renal and hepatic function.
Emergencies
You must know these:
Cardiac arrest:DC shock 150J biphasic, adrenaline 1mg IV (10ml of 1 in 10,000), amiodarone 300mg IV (if shockable rhythm)
Anaphylaxis: adrenaline 0.5mg IM (0.5ml of 1 in 1000)
Seizure: lorazepam 4mg IV (or if no IV access, diazepam 10mg PR)
Hypoglycaemia: 10% glucose 200ml IV or 20% glucose 100ml IV (repeat as needed),or glucagon 1mg IM (if no IV access)
Hyperkalaemia: calcium gluconate: 30ml 10% IV over 15 minutesTHEN actrapid insulin 10 units in 125ml 20% dextrose IV over 30 minutes + salbutamol 10mg neb
Bradycardia: atropine 500mcg IV (repeat every 3-5 minutes to maximum of 3mg if needed)
SVT: adenosine 6mg IV (can be followed by 12mg then 18mg if unsuccessful)
NB: must be given as a bolus and flushed quickly via a large vein.
Pulsed VT (without life threatening features): amiodarone 300mg IV over 10-60 minutes followed by 900mg over 24 hours through a large vein (900mg should be via central venous line)
Rapid tranquillisation of agitated patient at risk of self harm to self / others: lorazepam 1-2mg PO/IM or olanzapine 5-10mg PO/IM
Tranquilisation notes: use oral where possible; give half dose in elderly or renal impairment
Tramadol 50–100mg PO, PRN 4-6 hourly (max. 400mg), or QDS
Morphine sulphate oral solution (Oramorph) 10mg/5ml 5-10ml PO, PRN 2 hourly (reduce dosing interval or use alternative in renal impairment)
Morphine 1-10mg IV/IM/SC, PRN 4 hourly (max. 60mg; reduce dosing interval or use alternative in renal impairment)
As a rough guide, the IV dose of morphine is 0.1mg/kg. So for a 70kg person, the dose would be 7mg. If given in a non-monitored environment (theatres / intensive care / resus) this should be given with caution.
Morphine PCA (patient-controlled analgesia) 1mg bolus, 5 minute lockout (button only to be pressed by patient)
Opioid conversions
IV morphine = 3 x stronger than oral morphine
Subcutaneous morphine = 2 x stronger than oral morphine
Oxycodone = 2 x stronger than morphine (if same administration route)
Fentanyl patch: 24 hour oral morphine dose (in mg) ÷ 3 = fentanyl patch dose in mcg/hour (safe in renal impairment)
Buprenorphine patch: 24 hour oral morphine dose (in mg) ÷ 2.3 = buprenorphine patch dose in mcg/hour
Subcutaneous alfentanyl = 30 x stronger than oral morphine (safe in renal impairment)
Concept of background and breakthrough analgesia
For patients with ongoing severe pain, you should prescribe regular background (long-acting) analgesia with PRN breakthrough (short-acting) analgesia. The initial dose of background analgesia should be equivalent to the average dose of PRN analgesia they are currently needing over 24 hours. Breakthrough analgesia should be about 1/6 the dose of the total background analgesia dose. Prescribe this 4-hourly PRN. For example, if a patient has been needing 60mg Oramorph a day, convert them to 30mg MST BD, and also prescribe 10mg Oramorph PRN 4-hourly for breakthrough pain.
Subcutaneous PRN medications in palliative patients (all PRN 1-2 hourly)
Morphine 2.5mg (max. 20mg/24 hours) – for pain/SOB (use alternative in renal impairment, e.g. fentanyl/oxycodone)
Midazolam 2.5mg (max. 20mg/24 hours) – for anxiety and agitation (reduce dose in renal impairment)
Hyoscine butylbromide 20mg (max. 120mg/24 hours) – for bronchial secretions
Haloperidol 0.5-1.5mg (max. 5mg/24 hours) – for nausea and vomiting
Subcutaneous syringe driver in palliative patient (all over 24 hours)
Tailor to patient’s symptoms – content options include:
Morphine 10-20mg – for pain and breathlessness (use alternative in renal impairment, e.g. fentanyl/oxycodone)
Midazolam 10-20mg – for confusion without hallucinations (reduce dose in renal impairment)
Hyoscine butylbromide 40-120mg – for bronchial secretions
Haloperidol 2.5-5mg – for nausea and vomiting; or confusion with hallucinations
Cyclizine 75-150mg – for nausea and vomiting
Levomepromazine 5-25mg – for nausea and vomiting (2nd line)
Mild (>2.5mmol/L): Sando-K 2 tablets TDS x 3/7, or add 20-40mmol/L potassium chloride to each litre of IV fluids
Severe (<2.5mmol/L or ECG changes): 40mmol/L potassium chloride in 1L 0.9% saline over 4-6 hours (NEVER >10mmol/hour K+ outside ICU)
Hyperkalaemia
ECG and cardiac monitoring
Calcium gluconate 10ml 10% IV over 15 minutes if ECG changes (consider if severe, i.e. ≥6.5mmol/L, without ECG changes)
Actrapid insulin 10 units in 125ml 20% glucose IV over 30 minutes + 10mg salbutamol neb
Sodium zirconium cyclosilicate 10g PO TDS for up to 72 hours
Hypocalcaemia
Mild (>1.9mmol/L and asymptomatic): calcium (e.g. Sandocal or Calcichew) 1000mg BD + vitamin D if deficient
Severe (<1.9mmol/L or symptomatic): calcium gluconate 10ml 10% IV over 10 minutes – can be repeated until asymptomatic and usually needs to be followed by an infusion (50ml 10% calcium gluconate in 500ml 0.9% saline over 12 hours)
Hypercalcaemia
Replace fluid deficit with 0.9% saline and keep patient well hydrated (continuous IV fluids)
Severe (>3.5mmol/L or symptomatic): if calcium stops falling with IV fluids alone, consider IV bisphosphonate, e.g. zoledronic acid 4mg IV, depending on renal function (one-off dose)
Hypomagnesaemia
PO: magnesium aspartate 1 sachet (10mmol) BD x 3/7
IV: 5grams (20mmol) magnesium sulphate in 500ml 0.9% saline over 5 hours
Hypophosphataemia
PO: Phosphate-Sandoz 2 tablets TDS x 3/7
IV: Phosphate Polyfusor (50mmol in 500ml) 100-300ml over 12-24 hours depending on weight and severity OR sodium glycerophosphate 10mmol in 500ml 0.9% saline over 12 hours – must give through different cannula to other electrolytes if co-administering
Test your knowledge with a scenario…
A 34 year old homeless patient who drinks alcohol to excess presents with a withdrawal seizure after stopping drinking because he ran out of money to buy alcohol.
The patient has also been started on Fortisips nutritional supplements due to their low body mass index. Two days later, the patient’s electrolytes are checked and reveal Sodium 142 mmol/L; Potassium 2.6 mmol/L; Magnesium 0.4 mmol/L; Phosphate 0.4 mmol/L; Calcium 2.5 mmol/L. What is going on?
