What is the best course of action for a patient with a history of kidney stones, presenting with severe, radiating low back and side pain, difficulty breathing, nausea, and a pain scale of 6 after receiving 75mcg of Fentanyl (fentanyl), with normal blood pressure, no urinary or bowel symptoms, and no fever or chills?

Immediate Management of Suspected Renal Colic in the Emergency Department

This patient requires urgent urinalysis, immediate administration of intramuscular diclofenac 75 mg (or IV ketorolac if NSAIDs are not contraindicated), continued opioid analgesia with short-acting agents for breakthrough pain, and hospital admission if pain does not resolve within one hour of initial NSAID administration. 1, 2

Initial Assessment and Diagnostic Considerations

Rule out life-threatening alternative diagnoses immediately:

• In patients over 60 years, consider leaking abdominal aortic aneurysm as a critical differential diagnosis 1
• Examine the abdomen to establish the site of maximal tenderness and exclude signs of peritonitis 1
• Check vital signs to exclude shock and systemic infection—patients with shock or fever must be admitted immediately 1
• Although this patient is afebrile with normal blood pressure, the severity and radiation pattern strongly suggest renal colic 1

Perform urinalysis despite absence of urinary symptoms:

• Over 80% of patients with acute renal colic test positive for hematuria, which supports the diagnosis 1
• The absence of urinary symptoms does not exclude kidney stones, as the patient has a documented history of nephrolithiasis 1
• Alternative diagnoses should be considered if urinalysis is negative 1

Pain Management Strategy

First-line treatment: NSAIDs are superior to opioids alone

• Administer intramuscular diclofenac 75 mg immediately as the first-line analgesic for renal colic 1, 2
• NSAIDs are recommended as first-line treatment due to superior efficacy and safety profile compared to opioids alone 2
• NSAIDs reduce the need for additional analgesia and have fewer side effects than opioids 2
• The goal is to provide pain relief within 30 minutes of assessment 1

Continue opioid therapy for breakthrough pain:

• Since the patient has already received 75 mcg fentanyl with partial response (pain decreased from 10 to 6), continue short-acting opioids for breakthrough pain 2
• Fentanyl is appropriate for renal colic patients, particularly if there is any concern about renal function given the history of kidney stones 2, 3
• Administer additional doses of IV fentanyl (25-50 mcg) every 5-15 minutes as needed until adequate pain control is achieved 4, 5
• Avoid morphine, codeine, or tramadol as first-line agents if there is any renal impairment 3

Combination therapy is most effective:

• The combination of NSAIDs (ketorolac or diclofenac) with fentanyl provides superior pain control compared to either agent alone 4
• Research demonstrates that intramuscular ketorolac combined with fentanyl (either IV or intranasal) effectively controls severe renal colic pain 4

Monitoring and Admission Criteria

Reassess pain within one hour:

• Check the effect of analgesia by direct assessment or telephone within 60 minutes 1
• If pain has not been alleviated within 60 minutes of initial NSAID administration, arrange immediate hospital admission 1, 2
• Given this patient's current pain score of 6 after prehospital fentanyl, close monitoring is essential 1

Indications for immediate admission:

• Failure to respond to analgesia within one hour 1, 2
• Abrupt recurrence of severe pain 1
• Signs of sepsis or fever (urgent decompression via percutaneous nephrostomy or ureteral stenting required) 2
• Shock or systemic infection 1

Maintain pain control for at least six hours:

• Complete or acceptable pain control should be maintained for six hours or longer 1, 2
• Write continuous scheduled dosing orders rather than as-needed orders to prevent pain recurrence 1

Contraindications and Special Considerations

When NSAIDs are contraindicated:

• If NSAIDs are definitely contraindicated, use an opiate combined with an antiemetic such as morphine sulfate and cyclizine 1
• However, given this patient's history of kidney stones, assess renal function before using morphine 3
• If renal impairment is present, fentanyl remains the preferred opioid as it does not accumulate active metabolites in renal failure 2, 3

Avoid mixed agonist-antagonist opioids:

• Do not use mixed agonist and antagonist opioids as they may precipitate acute withdrawal syndrome in patients who have received fentanyl 1

Discharge Planning and Follow-up

If pain resolves and patient is discharged:

• Instruct the patient to drink plenty of fluids 1
• Advise voiding urine into a container or through a tea strainer to catch any identifiable calculus 1
• Provide clear instructions to contact the physician if pain worsens or unexpected symptoms develop 1
• Consider medical expulsive therapy (alpha-blockers) if imaging reveals stones >5 mm in the distal ureter 2

Common Pitfalls to Avoid

• Do not delay NSAID administration while waiting for diagnostic confirmation—the clinical presentation strongly suggests renal colic 1, 2
• Do not use standard opioid dosing protocols without considering renal function—always assess kidney function in patients with recurrent kidney stones 3
• Do not rely solely on opioids for pain control—NSAIDs are first-line and more effective 2
• Do not discharge patients with inadequate pain control—admission is required if pain persists beyond one hour despite appropriate analgesia 1, 2
• Do not assume absence of urinary symptoms excludes kidney stones—the clinical presentation and history are diagnostic 1