The momentum of kidney stone patient “expulsion” from the emergency department has never been greater. Big stone? No problem. Obstruction? No problem. Infection? That’s the problem. Some of these patients may require admission.

A recent interesting malpractice claims trend has prompted a reassessment of outpatient management of nephrolithiasis. Females with an active ureteral stone with obstruction and, most important, possible urinary tract infection (UTI) have returned with pyelonephritis and sepsis, suffering horrific outcomes. Urinary symptoms, other than those associated with acute ureterolithiasis, are often absent in these patients.

Although few recommendations deserve inclusion of an “always” or a “never,” this trend at least deserves some consideration in our approach to certain cases.

In England and Wales, 91 percent of deaths from nephrolithiasis were associated with kidney and ureteral stones, compared to lower tract stones, which accounted for 7.9 percent of deaths. Although the raw numbers aren’t alarming—mean 9.4 deaths per year from ureteric stones (141 deaths total) and 130.³ deaths per year from urolithiasis (1,954 deaths total) identified between 1999 and 2013—their report of increasing trends in developed nations is concerning. Although men had a higher incidence (1.3:1) of stones compared to women, mortality was significantly higher in females (1.5:1). Equally worrisome, urosepsis accounts for 25 percent of adult sepsis cases.¹

“This too shall pass,” a quote dating back to 1839, fits well with regard to stone size.²

It has been taught that stones ≥5 mm are unlikely to pass spontaneously. That’s a reasonable guideline, but what difference does it really make? If patients are pain-free or their pain can be controlled with oral analgesics, there are no indications for admission (eg, pyelonephritis, solitary kidney, etc.), and follow-up is available, then size isn’t critical for the disposition decision. Jendeberg et al reported multiple CT-related variables that may predict stone passage.³ Although limited by the study’s retrospective design and nonstandardized follow-up, their conclusion suggests our 5 mm line in the sand is less than clear. “The spontaneous passage rate in 20 weeks was 312 out of 392 stones, 98% in 0–2 mm, 98% in 3 mm, 81% in 4 mm, 65% in 5 mm, 33% in 6 mm and 9% in ≥6.5 mm wide stones.”³ Stone size appears to be relegated to an academic discussion with limited relevance to emergency medicine.

Hydronephrosis is practically synonymous with obstruction and is expected with active ureteral stones. However, an active stone that is unlikely to pass may prolong the duration of associated ureteral obstruction.³ In the context of possible infection, obstruction is important.