MP18-02 EVALUATING SPONTANEOUS STONE PASSAGE RATES DURING THE COVID-19 PANDEMIC

INTRODUCTION AND OBJECTIVE: During the COVID-19 pandemic our institution limited elective surgery including management of kidney stones. Additionally, patients themselves were reluctant to pursue elective surgery. This presented us a unique opportunity to reassess the natural history of symptomatic nephrolithiasis given potentially prolonged periods of conservative management. METHODS: A retrospective review was performed of patients presenting to the emergency room (ER) with flank pain secondary to nephrolithiasis from March to April of 2020 (COVID peak period of elective surgery limitations), and a comparative cohort from March and April 2019. Assessed outcomes included definitive stone treatment at initial presentation to the ER, rate of spontaneous stone passage, and time to elective surgery from initial ER presentation. Chi-square or Mann-Whitney U tests were utilized for dependent binary variables and continuous variables, respectively. A Kaplan Meier analysis was used to demonstrate differences in time to elective surgery between the two eras. RESULTS: Baseline characteristics did not differ between groups (Table). Patients discharged from the ER were more often offered medical expulsive therapy (71.6% vs 55.0%, p=0.026) during the COVID era. The rate of surgical stone management or stent placement at initial presentation did not differ, however, discharged patients waited longer from initial ER presentation to elective surgery (55.3 vs 33.1 days, p=0.02). Spontaneous stone passage rates were similar between groups despite the delay, and similar stone location and stone size between eras. CONCLUSIONS: During the height of the COVID pandemic, ER patients with symptomatic stones had similar characteristics at presentation but were more often offered MET. Spontaneous stone passage during the pandemic was no different than in 2019, despite a significant difference in time to elective surgery from initial presentation to the ER with flank pain .