What goes in the once-only section of the chart?
The once-only section is for a single dose to be given at a stated time, such as an emergency drug, a premedication or a loading dose.
- Write the drug, dose in a unit, route and the date and time, and sign it.
- Do not write an emergency drug as a regular prescription. A repeating prescription for adrenaline or naloxone is an error, and the exam instruction line tells you which section the marks are on.
- As-required drugs have their own section and need a maximum dose or frequency.
- In a real emergency, give the drug immediately and document afterwards.
How is anaphylaxis treated?
Adrenaline is the first-line drug in anaphylaxis, given intramuscularly and as early as possible.
- Adult dose: adrenaline 500 micrograms IM, which is 0.5 mL of 1 in 1000 (1 mg/mL), into the anterolateral thigh. It can be repeated after about 5 minutes if there is no improvement.
- Children are dosed by age band: use the BNF for Children or the Resuscitation Council UK chart.
- Do not confuse 1 in 1000 IM with 1 in 10 000, which is a different preparation used IV by experienced staff in specific circumstances.
- Give high-flow oxygen, and IV fluids for hypotension. Antihistamines and corticosteroids are not part of initial treatment.
What are the first-line drugs in other emergencies?
| Emergency | First-line principle | Exam trap |
|---|---|---|
| Acute severe asthma | Oxygen, nebulised salbutamol, ipratropium and a systemic corticosteroid; IV magnesium on senior advice | Do not delay steroids; check the BNF for doses |
| Hypoglycaemia | Fast-acting oral carbohydrate if able to swallow; IV glucose or IM glucagon (1 mg) if not | Recheck glucose and give longer-acting carbohydrate; glucagon works poorly in starvation and liver disease |
| Status epilepticus | IV lorazepam (4 mg in an adult); buccal midazolam or rectal diazepam if no IV access | A benzodiazepine comes first; phenytoin, levetiracetam or valproate are second line |
| Acute coronary syndrome | Aspirin 300 mg loading dose, analgesia and treatment per local pathway | Give oxygen only if saturation is below 94% |
| Acute pulmonary oedema | Sit upright, oxygen only if hypoxic, IV furosemide for fluid overload. Nitrates are not routine: use GTN only for ongoing ischaemia or severe hypertension, and avoid if hypotensive | Opioids and nitrates are not routine; follow NICE and local guidance |
| Hyperkalaemia with ECG changes | IV calcium gluconate, then insulin with glucose and nebulised salbutamol | Calcium protects the heart but does not lower potassium; stop contributing drugs |
| Opioid overdose | Naloxone, titrated to respiratory rate | Naloxone wears off sooner than many opioids, so monitor and repeat |
What are the first-hour principles for sepsis?
In suspected sepsis, speed matters: high-risk patients need IV antibiotics and fluids within the first hour, and others follow the NICE risk-stratified timings.
- The Sepsis Six: give oxygen, take blood cultures, give IV antibiotics, give IV fluids, measure lactate and monitor urine output.
- NICE guidance advises a crystalloid bolus of 500 mL over less than 15 minutes in adults who are hypotensive or have a high lactate, with reassessment after each bolus.
- Choose the antibiotic from the local sepsis guideline and the allergy history. Check the BNF.
How is oxygen prescribed as a drug?
Oxygen is a drug and should be prescribed with a target saturation range, not a fixed flow rate.
| Patient group | Target saturation | Note |
|---|---|---|
| Most acutely ill patients | 94-98% | Do not give routinely if saturation is already in range |
| At risk of hypercapnic respiratory failure, such as COPD | 88-92% | Use controlled oxygen, such as a 24% or 28% Venturi mask, until blood gases are known |
In cardiac arrest, anaphylaxis and major trauma, give high-flow oxygen initially. Titrate down to the target range once the patient stabilises.
How are IV fluids prescribed?
A fluid prescription names the fluid, the volume and the rate or duration.
- Resuscitation: NICE guidance advises a 500 mL crystalloid bolus over less than 15 minutes, then reassessment.
- Routine maintenance: roughly 25-30 mL/kg/day of water with about 1 mmol/kg/day each of sodium, potassium and chloride, and 50-100 g/day of glucose.
- Check electrolytes before adding potassium, and reduce rates in heart failure and renal impairment.
Check yourself
- What is the adult IM adrenaline dose in anaphylaxis, and what volume of 1 in 1000 is it?
- What is first-line in status epilepticus?
- Why must naloxone be monitored after the first dose?
- What target saturation applies to a patient with COPD?
- Which drug protects the heart in hyperkalaemia but does not lower potassium?
- What loading dose of aspirin is given in ACS?
- What are the Sepsis Six?
- Which chart section is used for an emergency drug?
Questions people ask
What is the adrenaline dose for adult anaphylaxis?
500 micrograms IM, which is 0.5 mL of 1 in 1000 (1 mg/mL), repeated after about 5 minutes if there is no improvement. Children are dosed by age band.
What target oxygen saturation should I prescribe?
Aim for 94-98% in most acutely ill patients and 88-92% in those at risk of hypercapnic respiratory failure, such as people with COPD.
What is first-line for status epilepticus?
A benzodiazepine, usually IV lorazepam. If there is no IV access, buccal midazolam or rectal diazepam is used. Second-line drugs follow if seizures continue.
Why can naloxone need repeating?
Its effect is shorter than that of many opioids, so respiratory depression can return. Patients need monitoring and may need repeat doses or an infusion.
Related revision notes
Sources: BNF; Resuscitation Council UK anaphylaxis guidance; British Thoracic Society oxygen guideline; NICE guidance on sepsis, intravenous fluids and epilepsies; UK Kidney Association hyperkalaemia guideline. These notes are for exam revision and are not patient-specific advice; in the exam and in practice, the BNF is the authority.
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