What pain reliever can a healthcare provider give a patient with appendicitis, considering their weight, age, medical history, and potential allergies?

Pain Management in Acute Appendicitis

Healthcare providers should immediately administer pain relief to patients with appendicitis using either oral NSAIDs (ibuprofen) for moderate pain or intravenous opioids (morphine) for severe pain, without withholding medication while awaiting diagnosis or surgery. 1

Immediate Analgesic Strategy

The outdated practice of withholding pain medication to avoid "masking" physical examination findings is harmful and should be abandoned. The American Academy of Pediatrics explicitly recommends providing immediate pain relief, as pain control actually facilitates better physical examination without affecting diagnostic accuracy 1. This represents a critical shift in clinical practice supported by high-quality evidence.

First-Line Options Based on Pain Severity

For moderate pain:

• Oral NSAIDs (ibuprofen) are recommended as first-line therapy 1
• Intravenous acetaminophen is an effective alternative that does not interfere with clinical findings or diagnosis 2
  • Dosing for adults ≥50 kg: 1,000 mg IV every 6 hours (maximum 4,000 mg/day) 3
  • Dosing for adults <50 kg: 15 mg/kg IV every 6 hours (maximum 75 mg/kg/day) 3
  • Administer as 15-minute IV infusion with minimum 4-hour dosing interval 3

For severe pain:

• Intravenous opioids (morphine) are indicated 1, 4
  • Starting dose in adults: 0.1-0.2 mg/kg IV every 4 hours as needed 5
  • Adjust based on pain severity, adverse events, patient age, and size 5
  • Rapid IV administration may cause chest wall rigidity and respiratory depression 5

Multimodal Analgesia Approach

Pain control should be a priority using opioids, NSAIDs, and acetaminophen in combination, as this does not result in delayed or unnecessary intervention 4. Acetaminophen can be used as adjunctive first-line therapy alongside other analgesics 6.

Evidence Supporting Safe Pain Management

A randomized clinical trial demonstrated that intravenous acetaminophen significantly reduced pain scores at 30 minutes, 1 hour, and 4 hours compared to placebo (p<0.001), without affecting Alvarado scores or physical examination findings 2. This confirms that appropriate analgesia does not compromise diagnostic accuracy.

Critical Pitfalls to Avoid

• Never withhold pain medication based on the outdated belief that it will mask physical examination findings—this practice causes unnecessary suffering and actually impairs examination quality 1
• Avoid dosing errors with IV acetaminophen by carefully distinguishing between different concentrations and between mg and mL, which could result in accidental overdose 3
• Monitor for respiratory depression with opioid administration, particularly with rapid IV bolus 5
• Use caution with acetaminophen in patients with hepatic impairment, active liver disease, alcoholism, chronic malnutrition, severe hypovolemia, or severe renal impairment (CrCl ≤30 mL/min) 3
• Recognize contraindications to morphine including known hypersensitivity, bronchial asthma, upper airway obstruction, respiratory depression without resuscitative equipment, and paralytic ileus 5

Special Population Considerations

Pediatric patients (≥2 years):

• Acetaminophen IV: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours (maximum 75 mg/kg/day) 3
• Minimum dosing interval of 4 hours 3

Elderly patients:

• Start morphine at lower end of dosing range and titrate cautiously while monitoring for side effects 5
• Consider age-related changes in drug metabolism and increased sensitivity to analgesics 7

Patients with renal or hepatic impairment:

• Start at lower doses and titrate cautiously for both opioids and acetaminophen 3, 5