What is the best course of action for a female patient with a history of kidney stones, presenting with severe low back and side pain, nausea, and difficulty breathing, who has been given fentanyl (synthetic opioid analgesic) and still reports a pain level of 6, with normal blood pressure and no urinary or bowel symptoms?

Immediate Management of Suspected Renal Colic

This patient requires immediate non-contrast CT imaging to confirm kidney stone diagnosis, continued aggressive pain management with NSAIDs as first-line therapy, and close monitoring for complications requiring urgent urological intervention. 1

Diagnostic Confirmation

Obtain non-contrast CT abdomen/pelvis (CT KUB) emergently to confirm suspected nephrolithiasis, as this is the gold standard imaging modality for acute flank pain with suspicion of stone disease. 1 The clinical presentation—severe unilateral flank pain radiating to the side, history of kidney stones, nausea, and pain unrelieved by position changes—is classic for ureteral colic, but imaging is essential to:

• Confirm stone presence, size, and location (critical for determining likelihood of spontaneous passage and need for intervention) 1
• Exclude alternative diagnoses requiring different management (abdominal aortic aneurysm, appendicitis, ovarian pathology) 2
• Identify complications such as hydronephrosis or complete obstruction 1

Do not delay imaging based on absence of hematuria—over 80% of patients with renal colic have microscopic hematuria, but its absence does not exclude stone disease, particularly in the setting of this classic presentation. 1

Pain Management Strategy

First-Line Analgesic Approach

Administer intravenous ketorolac 30mg IV immediately as the most effective analgesic for renal colic. 1 NSAIDs are superior to opioids alone for stone pain because they:

• Reduce ureteral spasm and inflammation 1
• Provide equivalent or superior pain relief compared to opioids 3
• Decrease need for additional opioid doses 3

The patient has already received 75mcg fentanyl with incomplete relief (pain 10→6), which is expected—opioids alone are suboptimal for renal colic. 1, 3

Adjunctive Opioid Management

Continue short-acting opioids (fentanyl 25-50mcg IV or hydromorphone 0.5-1mg IV) every 1-2 hours as needed for breakthrough pain not controlled by NSAIDs. 1, 4

• Target pain score ≤3/10 within 30-60 minutes 1
• Reassess pain every 30 minutes until adequate control achieved 1
• Add antiemetic (ondansetron 4mg IV or metoclopramide 10mg IV) for nausea 1

Critical Safety Consideration

Monitor respiratory status closely given recent fentanyl administration—the patient reported difficulty breathing for several hours, which may represent pain-related tachypnea but requires differentiation from opioid-induced respiratory depression. 4 Vital signs show normal blood pressure (123/88) and she is afebrile, reducing concern for sepsis or shock. 1

Exclusion of Urgent Complications

Immediately assess for red flags requiring emergent urological consultation: 1

• Fever or signs of infection (absent in this case—afebrile, no urinary symptoms) 1
• Solitary kidney or bilateral obstruction (obtain history) 1
• Acute kidney injury (check baseline creatinine if available; order stat basic metabolic panel) 1
• Intractable pain or vomiting despite aggressive management (current pain 6/10, manageable) 1
• Anuria (patient denies urinary symptoms, but confirm she is voiding) 1

This patient currently has NO absolute indications for emergency intervention, but requires close observation. 1

Disposition and Follow-Up Algorithm

If Pain Controlled and No Complications

Admit for observation if: 1

• Stone >5mm on CT (low spontaneous passage rate) 1
• Persistent severe pain despite maximal medical therapy 1
• Inability to tolerate oral intake due to nausea/vomiting 1
• Social factors preventing safe discharge 1

Discharge home with close follow-up if: 1

• Stone ≤5mm (high spontaneous passage rate ~70-90%) 1
• Pain controlled to ≤3/10 with oral medications 1
• Tolerating oral fluids 1
• Reliable patient with ability to return if symptoms worsen 1

Discharge Instructions (If Appropriate)

Prescribe oral NSAIDs as primary analgesic: 1

• Ibuprofen 600mg every 6 hours scheduled (not as-needed) for 5-7 days 1
• Avoid NSAIDs if: eGFR <30, active peptic ulcer disease, recent GI bleeding, or cardiovascular contraindications 5

Provide rescue opioid sparingly: 1

• Oxycodone 5mg every 4-6 hours as needed for breakthrough pain (maximum 10 tablets) 5
• Counsel on opioid risks including constipation, sedation, and addiction potential 4

Strain all urine to capture stone for analysis (guides future prevention strategies) 1

Ensure urological follow-up within 7 days with repeat imaging if stone not passed 1

Return immediately if: 1

• Fever >38°C (suggests infection/pyelonephritis requiring urgent antibiotics) 1
• Inability to urinate (suggests complete obstruction) 1
• Uncontrolled pain or vomiting 1

Common Pitfalls to Avoid

Do not assume musculoskeletal etiology despite initial lifting mechanism—the progression from localized back pain to severe unilateral flank pain with nausea and inability to find comfortable position is pathognomonic for ureteral colic, not muscle strain. 1 Musculoskeletal pain typically improves with rest and position changes. 1

Do not rely solely on opioids for pain control—this leads to inadequate analgesia, increased side effects, and higher opioid consumption. 1, 3 NSAIDs are first-line therapy. 1

Do not discharge without imaging—while clinical diagnosis may seem obvious, alternative diagnoses occur in 5-10% of suspected renal colic cases, including some requiring urgent intervention. 2

Do not prescribe long-term opioids for stone pain—most stones pass within 48 hours to 4 weeks, and chronic opioid use for this self-limited condition creates unnecessary dependence risk. 1, 5