Nephrolithiasis (Kidney Stones): Evaluation and Management
Medically Reviewed by Dr. M. Salar Raza | Official SCFHS 2026 Blueprint
Clinical Pathway
Nephrolithiasis typically presents with acute, severe, colicky flank pain that may radiate to the groin, often accompanied by hematuria, nausea, and vomiting. The gold standard imaging modality for diagnosing kidney stones is a non-contrast CT scan of the abdomen and pelvis. It offers high sensitivity and specificity for detecting stones, determining their size and location, and identifying associated complications like hydronephrosis. Initial management focuses on pain control (NSAIDs or opioids) and hydration. Stones smaller than 5mm often pass spontaneously.
Clinical Reasoning
A non-contrast CT is preferred over ultrasound or KUB x-ray because it can detect almost all types of stones (including radiolucent stones like uric acid stones, which may be missed on KUB) and provides precise anatomical detail. Ultrasound is a reasonable alternative in pregnant patients or children to avoid radiation exposure, but it is less sensitive for small stones or ureteral stones. For acute pain management, NSAIDs like ketorolac are often preferred over opioids as they directly decrease ureteral smooth muscle tone by inhibiting prostaglandin synthesis.
Sample MCQ
A 40-year-old man presents to the emergency department with sudden onset of severe, colicky right flank pain that radiates to his right groin. He cannot sit still and is constantly pacing the room. Urinalysis shows microscopic hematuria. What is the most appropriate imaging study to confirm the suspected diagnosis?
- AKidney, ureter, bladder (KUB) X-ray
- BRenal ultrasound
- CNon-contrast CT scan of the abdomen and pelvis
- DIntravenous pyelogram (IVP)
Correct Answer: Non-contrast CT scan of the abdomen and pelvis
The patient's presentation of colicky flank pain radiating to the groin with hematuria is classic for nephrolithiasis (renal colic). The gold standard and most appropriate imaging modality for suspected kidney stones is a non-contrast CT scan. It is highly sensitive and specific, can detect all types of stones, and provides information on size, location, and obstruction. KUB misses radiolucent stones and small stones. Ultrasound is less sensitive for ureteral stones. IVP is rarely used today due to the superiority of CT.
Related Clinical Topics
Acute Otitis Media (AOM) in Pediatrics: Diagnosis and Management
Acute Otitis Media (AOM) is characterized by acute onset of symptoms (fever, ear pain) and signs of middle ear inflammation, such as a bulging tympanic membrane. The first-line antibiotic therapy for AOM is Amoxicillin, given at a high dose (80-90 mg/kg/day). Amoxicillin is effective against the most common bacterial pathogen, Streptococcus pneumoniae. If the patient has been treated with amoxicillin in the past 30 days, or has concurrent purulent conjunctivitis, Amoxicillin-clavulanate is preferred to cover beta-lactamase-producing organisms like H. influenzae.
AIDS
AIDS (Acquired Immunodeficiency Syndrome) is the final, most severe stage of HIV infection, characterized by a profoundly compromised immune system that makes individuals highly susceptible to opportunistic infections and certain cancers. It is diagnosed when the CD4+ T-cell count drops below 200 cells/mm³ or when specific AIDS-defining opportunistic illnesses develop. The cornerstone of AIDS treatment is highly active antiretroviral therapy (HAART), a combination of drugs that suppress HIV replication, preserve immune function, and prevent further progression. HAART significantly reduces viral load, increases CD4+ T-cell counts, and improves overall health. Treatment also includes prophylactic antibiotics to prevent opportunistic infections and specific therapies for any active infections or cancers. Symptoms of AIDS are primarily due to the opportunistic infections and cancers that take advantage of the severely weakened immune system. Common manifestations include persistent fever, chronic diarrhea, significant unintentional weight loss, night sweats, fatigue, swollen lymph nodes, and recurrent severe infections like Pneumocystis pneumonia, Kaposi's sarcoma, and toxoplasmosis. Neurological complications such as AIDS dementia complex can also occur.
Bradycardia
Bradycardia is a medical condition characterized by a slower than normal heart rate, typically defined as fewer than 60 beats per minute (bpm) in adults. While sometimes physiological and benign, it can also indicate underlying cardiovascular or systemic issues that impair the heart's ability to effectively pump blood. Treatment for bradycardia depends on its underlying cause, severity, and the presence of symptoms. Asymptomatic bradycardia, especially in athletes, often requires no intervention. Symptomatic bradycardia may necessitate discontinuing or adjusting causative medications, treating underlying conditions, or in severe cases, implanting a permanent pacemaker to regulate heart rhythm. Acute, unstable bradycardia may require intravenous atropine or temporary pacing. Clinical manifestations range from asymptomatic presentation to severe symptoms depending on the degree of bradycardia and the patient's cardiovascular reserve. Common symptoms include fatigue, dizziness, lightheadedness, syncope (fainting), shortness of breath, and chest pain. In critical cases, it can lead to confusion, hypotension, and signs of organ hypoperfusion.
SMLE Preparation Resources
Master the 2026 SMLE
Explore more clinical protocols in the SMLEREVISE Clinical Knowledge Library.
Try the QBank & Scaled Mocks