What are the preoperative (preop) guidelines for a healthy adult patient with no significant medical history undergoing surgery?

Preoperative Guidelines for Healthy Adults Undergoing Elective Surgery

For healthy adult patients with no significant medical history undergoing elective surgery, the most critical preoperative interventions are: clear liquids permitted until 2 hours before surgery, light meals until 6 hours before surgery, comprehensive preoperative assessment focusing on aspiration risk factors and functional capacity, and avoidance of routine preoperative sedatives or pharmacologic prophylaxis. 1, 2

Preoperative Fasting Requirements

The cornerstone of preoperative preparation is appropriate fasting to minimize aspiration risk while avoiding unnecessary prolonged fasting:

• Clear liquids may be consumed up to 2 hours before procedures requiring general anesthesia, regional anesthesia, or procedural sedation 1, 2

  • Clear liquids include water, fruit juices without pulp, carbonated beverages, carbohydrate-rich nutritional drinks, clear tea, and black coffee 2
  • Alcoholic beverages should not be included as clear liquids 2

• Light meals or nonhuman milk may be ingested up to 6 hours before surgery 1, 2

  • This represents a significant departure from traditional "NPO after midnight" protocols 1

• Fatty foods, fried foods, or meat require extended fasting of 8 or more hours 1, 2

  • The amount and type of food ingested must be considered when determining appropriate fasting periods 1

Common Pitfall: The traditional practice of keeping patients NPO from midnight lacks quality evidence and results in unnecessary prolonged fasting, leading to patient discomfort, dehydration, and increased anxiety 1. The 2-6-8 hour rule (2 hours for clear liquids, 6 hours for light meals, 8+ hours for heavy meals) is now the evidence-based standard 1, 2.

Preoperative Assessment Components

A structured preoperative evaluation must be performed, focusing on specific risk factors rather than routine screening:

History and Physical Examination

• Conduct a review of pertinent medical records, physical examination, and patient interview as the most important components of preoperative evaluation 1, 3

• Specifically assess for aspiration risk factors:

  • Gastroesophageal reflux disease 1, 2
  • Dysphagia symptoms 1, 2
  • Gastrointestinal motility disorders 1, 2
  • Metabolic disorders, particularly diabetes mellitus 1, 2
  • Potential for difficult airway management 1

• Evaluate functional capacity using metabolic equivalents (METs) 1

  • Patients with good functional capacity (≥4 METs or ability to climb ≥2 flights of stairs) generally can proceed to surgery without further cardiac testing 4
  • An assessment of daily task performance correlates well with maximum oxygen uptake and helps stratify risk 1

• Document complete medication history including prescription medications, over-the-counter drugs, herbal supplements, and nutritional supplements 1, 4

  • Natural product use is common (approximately 25% of surgical patients) and may cause perioperative complications including effects on coagulation, blood pressure, and sedation 5

• Assess smoking and alcohol consumption as cessation at least 4 weeks before surgery can reduce respiratory and wound-healing complications 4

Patient Education and Verification

• Inform patients of fasting requirements and the reasons for them sufficiently in advance of their procedures 1

• Verify patient compliance with fasting requirements at the time of the procedure 1, 2

  • When fasting recommendations are not followed, compare risks and benefits of proceeding, considering the amount and type of substances ingested 1

• Provide preoperative counseling about surgical and anesthetic procedures to reduce anxiety and enhance recovery 4

Laboratory and Diagnostic Testing

Routine preoperative testing is not recommended for healthy patients; testing should be selective based on clinical indications:

• Complete blood count (CBC) is indicated only for:

  • Patients with history of anemia or recent blood loss 4
  • Liver disease or other hematologic disorders 4
  • Those undergoing cardiovascular or major surgery 4

• Electrolyte and renal function testing is recommended only for:

  • Patients with known renal conditions 4
  • Those undergoing neurosurgery or cardiovascular surgery 4
  • Patients taking medications that affect electrolytes 4

• ECG is indicated only for:

  • Patients with signs or symptoms of cardiovascular disease 4
  • Those undergoing high-risk surgery 4

• Chest radiography is not recommended routinely for asymptomatic patients, but may be considered for those with new or unstable cardiopulmonary symptoms 4

Key Point: The history and physical examination, rather than routine laboratory and diagnostic testing, are the most important components of preoperative evaluation 3. Unnecessary testing is costly and potentially dangerous 6.

Pharmacologic Interventions

Routine preoperative pharmacologic prophylaxis is NOT recommended for healthy patients without increased aspiration risk:

What NOT to Give Routinely

• Do not routinely administer preoperative anxiolytic drugs 1

  • Long-acting sedatives delay return to full psychomotor function, early mobilization, and feeding postoperatively, and increase delirium risk 1
  • While midazolam is commonly used for preoperative anxiolysis, its routine use is not supported for healthy patients 7

• Do not routinely administer histamine-2 receptor antagonists (such as famotidine) for patients with no apparent increased risk for pulmonary aspiration 1, 2

• Do not routinely administer gastrointestinal stimulants for patients without increased aspiration risk 1, 2

• Do not administer anticholinergics to reduce aspiration risk 1, 2

• Do not routinely administer antacids before elective procedures in patients with no apparent increased risk for pulmonary aspiration 1

When Pharmacologic Prophylaxis IS Indicated

Reserve pharmacologic interventions for patients with identifiable risk factors including emergency surgery, obesity, pregnancy, difficult airway, gastroesophageal reflux disease, delayed gastric emptying, or gastrointestinal motility disorders 2, 8:

• For at-risk patients, histamine-2 receptor antagonists may be administered:

  • Oral famotidine 40 mg at least 3 hours before surgery 2, 8
  • IV famotidine 20 mg at least 15-30 minutes before intubation 2

• Only nonparticulate antacids should be used when indicated for selected patients 1

• Gastrointestinal stimulants may be administered to patients at increased risk 2

Critical Distinction: The evidence shows these medications effectively modify risk factors (gastric pH and volume) but the literature is insufficient to demonstrate they directly prevent aspiration events 8. Therefore, they should be reserved for high-risk patients, not used routinely 1, 2.

Surgical Safety Checklist

The WHO Surgical Safety Checklist must be implemented as one of the most affordable and sustainable tools for reducing perioperative deaths 1:

• The checklist includes 19 items with three pause points used by the surgical team to confirm appropriate safety actions 1
• Use of the checklist significantly reduces perioperative morbidity and mortality in both low-middle-income and high-income countries 1
• Despite evidence of effectiveness, acceptance remains poor (20-40% in some settings), highlighting the need for systematic implementation 1

Special Considerations for Healthy Adults

The overriding principle is that intervention is rarely necessary simply to lower surgical risk unless indicated irrespective of the preoperative context 1:

• The purpose of preoperative evaluation is not to give "medical clearance" but to assess current medical status and provide a clinical risk profile 1

• No test should be performed unless it is likely to influence patient treatment 1

• For healthy adults with good functional capacity and no concerning history or physical examination findings, minimal additional testing or intervention is required 1, 4

• The preoperative consultation may represent the first careful cardiovascular evaluation in years, making thorough history and physical examination particularly valuable 1