MP10: Does arrival pain severity predict stone characteristics or short-term outcomes in emergency department patients with acute renal colic?

Abstract

Introduction: Renal colic is among the most painful conditions that patients experience. The main outcome determinants for patients with renal colic are stone size, location and hydronephrosis; however, little is known about the association of pain with these parameters. Our objective was to determine whether more severe pain is associated with larger stones, more proximal stones or more severe hydronephrosis, findings that might suggest the need for advanced imaging, hospitalization or early intervention. Methods: We used administrative data and structured chart review to study all adult emergency department (ED) patients in two cities with a renal colic diagnosis over one-year. Patients with missing imaging results or pain scores were excluded. Triage nurses recorded numeric rating scale (NRS) pain scores on arrival. We stratified patients into mild (NRS <4), moderate (NRS 4-7) and severe (NRS 8-10) pain groups, as per CTAS guidelines. Stone size (mm) and location (proximal, middle, distal ureter, or renal) were abstracted from imaging reports, while index admissions were determined from hospital discharge abstracts. We used multivariable linear regression to determine the association of arrival pain with stone characteristics and hydronephrosis severity (primary outcome), and we used multivariable logistic regression to determine the association of pain with index hospitalization (secondary outcome). We also performed a stratified analysis looking at ureteral vs. kidney (intrarenal) stones. Results: We studied 1053 patients, 66% male, with a mean age of 48 years. After controlling for patient and disease characteristics, we found no significant association between pain severity and stone size (b=−0.0004; 95%CI = -0.0015, 0.0008) or stone location (b = 0.0045; 95%CI: -0.020, 0.029). Nor did we find an association between pain and hydronephrosis severity (b = 0.016; 95%CI: -0.053, 0.022, p = 0.418). Stratified analyses using a Bonferroni correction for multiple comparisons revealed the same absence of associations in the kidney and ureteral stone subgroups. Arrival pain did not predict index admission (OR = 0.82, 95% CI: 0.59, 1.16). Conclusion: Arrival pain scores are not associated with stone size, stone location or hydronephrosis severity, and do not predict index visit hospitalization in ED patients with renal colic. Severe pain should motivate efforts to minimize treatment delays, but do not suggest the need to modify advanced imaging or admission decisions.

Correlation of Severity of Renal Colic With Clinical, Laboratory, and Radiological Parameters: An Emergency Department-Based Prospective Observational Study

“…Sasmaz and Kirpat found that the mean VAS score of the patients with hydronephrosis was statistically higher than those without hydronephrosis (p < 0.001) [ 10 ]. However, Splinter et al did not find any significant correlation between arrival pain scores and the degree of hydronephrosis (b = 0.016; 95% CI: -0.053, 0.022, p = 0.418) [ 12 ].…”

“…In a study done by Gourlay et al, they found a weak negative association (adjusted OR=0.96) between pain severity and stone width indicating that smaller stones were more symptomatic [ 11 ]. Contrarily, the study by Splinter et al which correlate arrival pain scores with stone size also found that smaller stones caused more pain when compared to larger stones (b=−0.0004; 95% CI: -0.0015; 0.0008) [ 12 ]. Similar results were also obtained by Shih et al (p=0.025) [ 7 ].…”

“…Also, it was observed that proximal ureteral stones caused the highest rate of symptoms (100%) [ 8 ]. Splinter et al in a similar study correlating arrival pain scores in renal colic with the location of stone did not find any significant correlation (b = 0.0045; 95% CI: -0.020, 0.029) [ 12 ].…”

“…Gourlay et al and Splinter et al reported that there was no significant correlation of pain with stone size, location, and patient outcomes. On the other hand, Portis et al in a study found that pain score was an independent predictor of surgical outcome [11][12][13]. However, a study by Sasmaz and Kirpat found a significant correlation of pain severity with hydronephrosis and biomarkers like C-reactive protein and Neutrophil-Lymphocyte ratio [10].…”