From the Guidelines
Patients should generally avoid taking oral tablets when fasting for surgery, but can take essential medications with a small sip of water up to 2 hours before surgery, as recommended by the most recent guidelines 1. The reason for restricting oral intake before surgery is to prevent aspiration of stomach contents during anesthesia, which can cause serious complications. However, the latest evidence suggests that preoperative fasting from midnight is unnecessary in most patients, and clear fluids can be consumed until 2 hours before anesthesia, while solids can be allowed until 6 hours before anesthesia 1.
Essential Medications
- Essential medications like heart medications, blood pressure medications, anti-seizure drugs, and Parkinson's disease medications can and should be taken with a small sip of water (about 30 ml) even during the fasting period.
- These medications should be taken as prescribed by the healthcare team, and the patient should not stop taking them without consulting their doctor.
Non-Essential Medications
- Diabetes medications (especially insulin and oral hypoglycemics), blood thinners, and non-essential supplements should usually be held before surgery unless specifically instructed otherwise by the anesthesiologist or surgeon.
- The healthcare team will provide specific instructions on which medications to take or avoid before surgery, and the patient should follow these instructions carefully.
Preoperative Fasting Guidelines
- The latest guidelines recommend that patients drink clear fluids until 2 hours before anesthesia, and solids can be allowed until 6 hours before anesthesia 1.
- These guidelines are based on the latest evidence, which suggests that preoperative fasting from midnight is unnecessary in most patients, and that clear fluids can be consumed until 2 hours before anesthesia without increasing the risk of aspiration or regurgitation 1.
From the Research
Preoperative Fasting and Medication Administration
- The question of whether patients can have oral tablets while fasting for surgery is complex and depends on various factors, including the type of medication and the patient's individual needs 2, 3.
- Studies have shown that preoperative fasting times are often longer than recommended, with mean fasting times for solids ranging from 12 to 15 hours 3, 4.
- However, guidelines suggest that patients should be allowed to take their regular medications, including oral tablets, on the day of surgery, unless otherwise specified by their healthcare provider 2, 5.
- The type of medication is also an important consideration, with some medications, such as beta-blockers and calcium channel blockers, recommended to be continued on the day of surgery, while others, such as angiotensin-converting enzyme inhibitors, may need to be withheld 2.
Medication Administration and Fasting
- Research has shown that many patients do not receive their prescribed medications preoperatively, with one study finding that 45% of cardiac prescriptions were not administered 3.
- The use of aspirin, beta-blockers, and statins has been shown to reduce perioperative mortality and myocardial infarction in high-risk patients undergoing major vascular surgery 6.
- However, the administration of these medications during preoperative fasting is not well established, and further research is needed to determine the best practices for medication administration in this context 5, 4.
Current Guidelines and Recommendations
- Current guidelines recommend minimizing perioperative fasting, with a 2-hour preoperative fast after clear fluids and early recommencement of oral food and fluid intake postoperatively 5.
- The American Society for Parenteral and Enteral Nutrition recommends standardized grading systems for guideline recommendations, but the quality of guidelines varies, with some guidelines lacking systematic methodology and transparency 5.
- Further research is needed to improve guideline quality and to establish best practices for preoperative fasting and medication administration 5, 4.