Evaluation of fluid absorption during flexible ureteroscopy in an in vivo porcine model.

OBJECTIVE: To evaluate the relationship between renal pelvis pressure and fluid absorption during ureteroscopy (URS) in a live porcine model. MATERIALS AND METHODS: Flexible URS (fURS) was performed in anaesthetised female Yorkshire pigs. Prior to performing fURS, a 0.3556-mm (0.014″) pressure-sensing guidewire (Comet™, Boston Scientific) was placed to monitor renal pelvis pressure. A simulated fURS procedure was then performed for 1 h. Infusion of irrigation fluid (5% ethanol in saline) at target renal pelvis pressures (37-150 mmHg) was maintained for 1 h using a pressure bag and real-time feedback from the pressure-sensing guidewire. Venous blood was sampled every 10 min. The volume of irrigation fluid absorbed was estimated with established equations. RESULTS: A URS procedure was performed in vivo in 18 porcine kidneys and the volume of irrigation fluid absorbed during the 1 h URS was calculated. The mean (SD) volume of irrigation fluid absorbed after 1 h of simulated URS was 7.6 (5.7), 10.8 (7.1), 26.0 (15.8), and 56.8 (22.3) mL at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively. Compared with URS with renal pelvis pressure of 37 mmHg, the volume of fluid absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (P = 0.026 and P = 0.047, respectively). In addition, compared with URS with renal pelvis pressure of 37 mmHg, the rate of absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (both P < 0.001). CONCLUSION: In this study of an in vivo porcine model of URS, increasing renal pelvis pressures during URS were associated with increases in irrigation fluid absorption and increases in the rate of fluid absorption.

Predicting Septic Shock After Emergent Ureteral Stenting in Stone-Related Obstruction and Presumed Infections.

Introduction: Systemic inflammatory response syndrome (SIRS) criteria have long been used to predict septic shock. The sequential organ failure assessment and quick sequential organ failure assessment (qSOFA) scores have been suggested to be more accurate predictors. This study aims to compare SIRS and qSOFA for predicting of septic shock in the setting of retrograde ureteral stenting for obstructing stones and concomitant urinary tract infection. Methods: A retrospective review of records at two centers of consecutive patients was performed. Patients with unilateral ureteral obstruction by a stone who underwent ureteral stent placement and suspicion of urinary tract infection were identified. Primary endpoints were SIRS and qSOFA positive scores, intensive care unit admission, and vasopressor requirements. Results: A total of 187 patients were included. SIRS criteria were met in 103 patients (55.1%) and in 30 patients who experienced septic shock. qSOFA criteria were met for 24 patients (12.8%) and in 18 patients who experienced septic shock. Specificity for postoperative septic shock was significantly higher for qSOFA than for SIRS criteria (75 vs 29.1%, McNemar test p < 0.001). Both SIRS and qSOFA had significant areas under the curve (AUC), qSOFA had a fair AUC of 0.750, p = 0.001, whereas SIRS had a poor AUC of 0.659, p = 0.008. Univariate logistic regression of SIRS and qSOFA for septic shock showed: qSOFA (odds ratio [OR] 46 [0.25-228], p = 0.001) and SIRS (OR 2.29 [0.716-7.37], p = 0.162). Conclusion: Although SIRS offers higher sensitivity, qSOFA score may offer advantages over SIRS criteria in evaluation of risk for septic shock for patients who present with obstructing ureteral stone and urinary tract infection.

Diabetes mellitus is associated with increased risk of positive qSOFA score but not with increased ICU admission in patients undergoing ureteral stent placement for ureteral stone and suspected infection.

INTRODUCTION: Patients presenting with an obstructing ureteral stone and urinary tract infection (UTI) are at risk for severe infectious complications. Historically, diabetes mellitus (DM) was considered a risk factor for the development of septic shock in these patients. This study aimed to evaluate DM's impact on risk of septic shock in ureteral stent placement for ureteral stone and presumed UTI. METHODS: An institutional review board-approved, retrospective review was performed at two institutions. All patients who met the following criteria from July 2016 to April 2020 were included in the study: emergency department visit with obstructing ureteral stone, concern for UTI, and ureteral stent placement. The primary outcome of interest was the development of postoperative septic shock defined by sepsis with hypotension requiring vasopressor support for at least one hour. RESULTS: The study cohort was made up of 187 patients. Median age was 61 (range 16-91). Males represented 40.1% (n=75) of the population, while DM was present in 26.2% (n=49). Thirty-five of 143 patients (18.7%) met the criteria for postoperative septic shock. Quick Sequential Organ Failure Assessment (qSOFA) criteria were met by 11 (22.4%) patients with DM compared to 13 (9.5%) of patients without DM (p=0.026). This difference did not translate into significant differences in use of vasopressors, with DM cohorts requiring pressors in 11 (22.4%), and 241 (17.5%) in non-DM (p=0.523). Purulent urine was more frequently described in patients with DM (22 [44.9%] vs. 342 [4.8%], p=0.011). Intensive care unit (ICU) admissions were similar between DM and non-DM at 13(27.1%) vs. 29 (21.2%), respectively (p=0.543). ICU stay and length of stay were similar between cohorts. CONCLUSIONS: In this multicenter study of patients who underwent ureteral stenting for ureteral stone and presumed UTI, DM was not associated with an increased risk of development of septic shock but was associated with an increased risk of positive qSOFA score.

Opioids and Kidney Stones.

In recent years, the use of opioids in medical practice has come under significant scrutiny. This, in part, is owing to evidence of overprescription and overuse of opioid medications, as well as the unintended consequences and side effects for patients who take these medications. Here, we review the role of opioids and the responsible use of these medications with respect to kidney stone disease and surgical interventions for kidney stones.