Kids with Kidney Stones
Kidney stones are a relatively common entity encountered on the adult side of the ED, but while kids are not just little adults, some will develop adult-like problems. There has been an increase in incidence of renal stones in children (as well as adults) over the past few decades. (http://www.reuters.com/article/)
But, let’s not get carried away, it is still a relatively unusual condition in children… so how do we find this needle in the haystack? The answer is the same as with all conditions: a good H+P and avoiding premature closure of your differential.
Increases risk of renal calculi (the abridged list):
- Diet (likely why we’ve seen an increase in stones – I’m surprised we don’t see more)
- High animal protein, salt, and refined carbohydrates (can you say Fast Food)
- Soft drinks (because of phosphoric acid) [Another strike against Fast Food joints]
- Anatomic Anomalies
- Examples = Vesicoureteral reflux, UPJ obstruction, neurogenic bladder
- Lead to urinary stasis and predispose to infection
- Prolonged steroids (asthma pt with flank pain?)
- Chemotherapy (because our pts with cancer don’t have enough problems)
- Loop Diuretics
- Medical Problems
- Inflammatory Bowel Disease and GI Malabsorption
- Seizure D/O being treated with Ketogenic Diet
- Leukemia/Lymphoma (plus they get chemo)
- Cystic Fibrosis
- Renal Tubular acidosis
- Recurrent urinary tract infections
- Immobilization (recent ortho procedure?)
- Family Medical History (~75% will have family hx: you can’t outrun your genetics)
- As with all pediatric conditions – it depends on age
- Older children typically present, as adults, with typical colicky flank pain and hematuria
- Younger kids will more likely have nonspecific vomiting and irritability
- One study found:
- Prior urolithiasis, nausea, vomiting, lack of dysuria, and microscopic hematuria to be significantly associated with urolithiasis.
- Fever, dysuria, and CVA tenderness to be inversely associated with urolithiasis
- Put Kidney Stones on the DDx when you are considering:
- Urinary tract infection
- Torsion (Testicular or Ovarian)
- Consider with c/o abdominal pain, +/- vomiting, and without another clear etiology
- No lab makes the Diagnosis
- BUN/Cr useful to define renal function
- Microscopic hematuria (2-5 RBCs/HPF) often present, but may be absent in ~15%
- “Dry”/Non-contrast CT is gold standard now as it can detect renal and ureteral stones
- U/S is good for detecting renal stones, but terrible at finding ureteral stones
- Consider starting with U/S, but if negative may need to proceed to Dry CT.
Schissel BL, Johnson BK. Renal Stones: Evolving Epidemiology and Management. Pediatric Emergency Care: 27(7), July 2011, pp.676-681
Sas DJ. An Update on the Changing Epidemiology and Metabolic Risk Factors in Pediatric Kidney Stone Disease. Clin J Am Soc Nephrol. 2011, Aug; 6(8); pp.2062-8.
Persaud AC, Stevenson MD, McMahon DR, et al. Pediatric Urolithiasis: Clinical Predictors in the Emergency Department. Pediatrics. 2009;124:888-894.