AS3.6 | Premedication Selection and Prescription for Surgical Patients — Summary & Reflection

KEY TAKEAWAYS

Premedication is the administration of drugs before anaesthesia induction to achieve one or more of five goals: anxiolysis, analgesia, aspiration prevention, PONV prophylaxis, and autonomic modification. Drug selection must match the indication to the patient's risk profile. Benzodiazepines (midazolam 5-7.5 mg orally) are first-line for anxiolysis in healthy adults — reduce dose or avoid in elderly, severe COPD, obstructive sleep apnoea, and cognitive impairment. Aspiration prophylaxis (sodium citrate 30 mL orally + ranitidine 150 mg orally + metoclopramide 10 mg) is mandatory before emergency surgery and high-risk elective cases. Metoclopramide is contraindicated in Parkinson's disease — use domperidone instead. PONV prophylaxis with ondansetron 4-8 mg IV and dexamethasone 4-8 mg IV at induction is used for high-risk patients; dexamethasone causes hyperglycaemia — monitor glucose in diabetics. Glycopyrrolate 0.2 mg IM is preferred over atropine as an antisialogogue because it does not cross the blood-brain barrier. Every premedication prescription must state drug name, dose, route, and timing. After sedative premedication on the ward, monitor SpO2, respiratory rate, and consciousness using the Ramsay Sedation Scale.

REFLECT

Review the prescription charts of three consecutive patients on your next surgical ward attachment. For each patient who received a premedication, identify: what was the indication, was the drug choice appropriate, was the dose adjusted for age or comorbidity, was a contraindication present that should have changed the choice, and was the prescription written in a complete and unambiguous format. For any patient who did NOT receive a premedication, consider whether one was warranted and, if so, what you would have prescribed. Discuss your findings with the supervising anaesthesiologist or the ward pharmacist.