What is the best drug for pre-operative (pre-op) medication?

Best Preoperative Medication for Surgery

Short-acting midazolam is the preferred preoperative medication for most surgical patients, with careful consideration of age and comorbidities.

Rationale for Midazolam as First Choice

Midazolam is the preferred preoperative anxiolytic medication for several reasons:

• It provides effective anxiolysis with shorter duration of action compared to other benzodiazepines 1
• It has amnestic properties that help reduce recall of perioperative events 2
• It reduces postoperative nausea and vomiting compared to placebo (25% vs 50%) 2
• It significantly improves patient satisfaction, with 85% of patients recommending it compared to only 42% with placebo 2

The ERAS Society strongly recommends avoiding long-acting anxiolytics, particularly in the elderly, but acknowledges that short-acting anxiolytics like midazolam (1-2 mg) can be appropriate in selected cases 1.

Dosing Recommendations

• Standard adult dose: 0.02 mg/kg IV (typically 1-2 mg) administered 15-20 minutes before the procedure 3
• Elderly patients (>65 years): Reduce dose by 50% (typically 0.5-1 mg) 3
• For enhanced amnesia: Up to 0.05 mg/kg (maximum 4 mg) may be used when lack of recall is beneficial 3

Special Populations and Considerations

Elderly Patients

• The American Geriatrics Society Beers Criteria strongly advises against using benzodiazepines in patients aged 65+ due to increased risk of cognitive impairment, delirium, and falls 1
• Consider alternatives like melatonin for elderly patients, which has been shown to reduce anxiety compared to placebo and may be as effective as midazolam with fewer side effects 1

Patients with High Risk for PONV

• Preoperative hyoscine patches can be used in patients with high risk for postoperative nausea and vomiting, but should be avoided in the elderly 1
• Midazolam itself has antiemetic properties that may reduce PONV 2

Multimodal Approach

• Acetaminophen can be continued up to the day of surgery as part of multimodal analgesia 4
• Gabapentin may be continued for patients already taking it for pain management 4
• NSAIDs and gabapentinoids are not recommended for preoperative use 1

Alternatives to Midazolam

• Propofol: 20 mg IV has been shown to be as effective as midazolam 2 mg IV for reducing anxiety when administered approximately 5 minutes before entering the operating room 5
• Melatonin: Effective for preoperative anxiety with a good safety profile, especially in elderly patients 1
• Passionflower: Has demonstrated reduction in anxiety with a good safety profile in the perioperative setting 1
• Lavender: Has shown efficacy and safety in treating anxiety, including preoperatively 1

Common Pitfalls and Caveats

1. Avoid long-acting benzodiazepines: They impair psychomotor recovery after general anesthesia, reducing patients' ability to ambulate, eat, and drink 1

2. Be cautious with drug interactions: Midazolam clearance is reduced when given with CYP3A4 inhibitors like erythromycin, diltiazem, and verapamil 6

3. Monitor for respiratory depression: Particularly when combined with opioids or other CNS depressants 3

4. Timing matters: For optimal effect (lack of recall), IV midazolam should be administered 15-20 minutes before the anticipated procedure 3

5. Avoid in certain conditions: Use caution in patients with respiratory compromise, as midazolam may cause upper airway obstruction in rare instances 3

By following these evidence-based recommendations, the appropriate use of preoperative medication can significantly improve patient experience while minimizing risks associated with surgery and anesthesia.