A 20-year-old white male presents to the Emergency Department with the sudden onset of right flank pain, diaphoresis, nausea and vomiting. The pain is severe, classified as a "15 out of 10" by the patient and radiates to the left testicle. The patient has no prior medical history and his past surgical history is significant for an appendectomy at age 17. He takes no medications and has no allergies. Social history is as follows: chews tobacco occasionally, ingests alcohol socially, no other drug use. He is a college student hired as summer help for the county road crew and lives with his parents.

On exam you find a well-developed, well-nourished male with sunburn on the face, arms and neck. He is in significant painful distress, unable to sit or lie still.

Vital Signs:

• 130/90, 112, 24, 99.2 po
• Skin: diaphoretic
• Abdomen: soft, near absent bowel sounds, ? tenderness LLQ
• GU: normal male genitalia, both testicles descended and non-tender

Laboratory Data:

• urinalysis: dip 4+ for blood, micro pending
• chemistries including BUN/cr pending
• complete blood count pending

Questions:

• What is your differential diagnosis?
• How are you going to evaluate this patient?
• What is the disposition of this patient?

Differential Diagnosis

Includes but is not limited to:

• Renal calculus
• Retroperitoneal bleed
• Testicular torsion
• Thrombotic event in kidney
• Dissecting aneurysm
• Drug-seeking behavior

An IV was started in this patient when the blood were drawn. Consent for a possible IVP was obtained and narcotics were administered for pain relief. The patient was hydrated with normal saline. The patient described relief with the narcotics and also described migration of the pain lower down his flank and more in his scrotum. Laboratory studies returned with normal results except for the urine microscopic exam which revealed >50 rbc/hpf.

Working Diagnosis: Renal Calculus and Colic

Discussion

• Renal calculi are very common and it is estimated that 2%-5% of the population will suffer from a urinary stone at some point in their life. Calculi usually occur in the age group 20-50 years and males are more commonly afflicted than females by a 3:1 ratio. Stones tend to be more common in the warmer months, possibly because of increased oxalate in the diet (leafy, green vegetables) and, frankly, I've seen occasions of a flurry of stones in the first hot days before people are hydrated enough and acclimatized to the heat. Ingestion of large amounts of milk and cheeses may lead to a predisposition to forming calcium stones.
• The majority of stones are calcium oxalate occasionally with calcium phosphate. Uric acid stones comprise approximately 10%, magnesium-ammonium-phosphate stones 15%. The latter are associated with urea-splitting bacterial urinary tract infections.
• The size of a stone determines the possibility of passage through the ureters. Calculi of greater than 8mm frequently require surgical removal. Stones less than 5 mm frequently pass spontaneously. Patients with stones greater than 5 mm may need hospitalization for observation and management.
• Stones may lodge in the calyx, at the uteropelvic junction, at the pelvic brim or at the uretovesicular junction. If complete obstruction, there may be no hematuria. Alternatively, one third of patients present with gross hematuria.

How Are You Going to Evaluate This Patient?

Some would argue that in a classic case of nephrolithiasis such as this, no further studies are warranted emergently because:

1. An "un-prepped" IVP is not as helpful in delineating a cause of non-calculus disease and
2. A positive study for stone or obstruction would not change the management decisions which are based on clinical criteria. However, current practice is usually to determine first that stone disease actually exists and secondly the presence or absence of obstruction. The latter may be more a determinant in projecting disability and follow-up.

A KUB is frequently the isolated radiograph used to provide first pass information regarding a stone. 90% of renal stones are composed of calcium oxalate, cystine, calcium phosphate or magnesium-phosphate crystals and are therefore radiopaque. Unfortunately this study may be obscured because of radiodense phleboliths, mesenteric lymph nodes, bowel gas and stool or by the stone overlying the sacrum and bony pelvis.

IVP has been held as the "gold standard" of evaluation for renal stones. It establishes the diagnosis in 90% of the cases and determines the degree of obstruction. After injection of an iodinated dye, the first film is taken at 5 minutes. Delay in the nephrogram is the most reliable and early indicator of a stone. Standard films are then obtained at 10, 20, and 60 minutes. Local protocols may differ. If the dye is excreted by the affected kidney, the column of dye is observed for dilatation and length of the ureter. Degree of dilatation of the ureters and dilatation or blunting of the calyces are helpful in determining hydronephrosis. Columnization, or the ability to see nearly the entire length of the ureter on one view, indicates an increased volume within the ureters and implies obstruction. Repeated views of abrupt termination of dye flow at the same level indicates a stone or obstruction. Occasionally, the pain is relieved as the stone is passed during the IVP, most likely as a result of the increased osmotic load.

The contraindications for IVP include renal insufficiency (relative contraindication, and may be affected by the presence of the newer contrast media) and prior contrast reactions. Contrast reactions are poorly understood and the incidence is low. If absolutely necessary, contrast administration may be preceded by the administration of steroids.

You might try to get consent for IVP contrast prior to the administration of narcotic analgesia to allay concerns of altered judgment after medication, although, realistically, this isn't always possible.

More recently, ultrasound in the ED has been used to assess the degree of obstruction and hydronephrosis. In patients in whom the diagnosis is unclear, bedside ultrasound may be useful in determining the absence of any dilatation in the well-hydrated patient and, therefore, the unlikelihood of renal calculus (Heeler and Jehle, Ultrasound in Emergency Medicine).

What Is the Disposition of the Patient?

Most patients can be managed as an outpatient with the following guidelines:

• Maintain adequate hydration and appropriate level of analgesia
• Strain all urine and attempt to bring it back for analysis
• Return for intractable pain, vomiting, fevers
• Return for an outpatient urologic evaluation in 1-2 weeks

Patients should be admitted if:

• They are unable to tolerate pain
• They are unable to tolerate po intake
• There is evidence of extrasavation of urine on IVP

Urology consult should be obtained emergently if there is evidence of obstruction and infection.

This patient had an IVP and upon return to the ED from Radiology, he stated he no longer had symptoms. He was given a strainer, a specimen jar and an appointment for GU in two weeks. He returned with a calcium oxalate stone.