Time to Appendectomy and Risk of Complicated Appendicitis and Adverse Outcomes in Children.

Importance: Management of appendicitis as an urgent rather than emergency procedure has become an increasingly common practice in children. Controversy remains as to whether this practice is associated with increased risk of complicated appendicitis and adverse events. Objective: To examine the association between time to appendectomy (TTA) and risk of complicated appendicitis and postoperative complications. Design, Setting, and Participants: In this retrospective cohort study using the Pediatric National Surgical Quality Improvement Program appendectomy pilot database, 2429 children younger than 18 years who underwent appendectomy within 24 hours of presentation at 23 children's hospitals from January 1, 2013, through December 31, 2014, were studied. Exposures: The main exposure was TTA, defined as the time from emergency department presentation to appendectomy. Patients were further categorized into early and late TTA groups based on whether their TTA was shorter or longer than their hospital's median TTA. Exposures were defined in this manner to compare rates of complicated appendicitis within a time frame sensitive to each hospital's existing infrastructure and diagnostic practices. Main Outcomes and Measures: The primary outcome was complicated appendicitis documented at operation. The association between treatment delay and complicated appendicitis was examined across all hospitals by using TTA as a continuous variable and at the level of individual hospitals by using TTA as a categorical variable comparing outcomes between late and early TTA groups. Secondary outcomes included length of stay (LOS) and postoperative complications (incisional and organ space infections, percutaneous drainage procedures, unplanned reoperation, and hospital revisits). Results: Of the 6767 patients who met the inclusion criteria, 2429 were included in the analysis (median age, 10 years; interquartile range, 8-13 years; 1467 [60.4%] male). Median hospital TTA was 7.4 hours (range, 5.0-19.2 hours), and 574 patients (23.6%) were diagnosed with complicated appendicitis (range, 5.2%-51.1% across hospitals). In multivariable analyses, increasing TTA was not associated with risk of complicated appendicitis (odds ratio per 1-hour increase in TTA, 0.99; 95% CI, 0.97-1.02). The odds ratios of complicated appendicitis for late vs early TTA across hospitals ranged from 0.39 to 9.63, and only 1 of the 23 hospitals had a statistically significant increase in their late TTA group (odds ratio, 9.63; 95% CI, 1.08-86.17; P = .03). Increasing TTA was associated with longer LOS (increase in mean LOS for each additional hour of TTA, 0.06 days; 95% CI, 0.03-0.08 days; P < .001) but was not associated with increased risk of any of the other secondary outcomes. Conclusions and Relevance: Delay of appendectomy within 24 hours of presentation was not associated with increased risk of complicated appendicitis or adverse outcomes. These results support the premise that appendectomy can be safely performed as an urgent rather than emergency procedure.

Beyond perforation: Influence of peritoneal contamination on clinical severity and resource utilization in children with perforated appendicitis.

PURPOSE: The purpose of the study was to explore the relationship between the degree of peritoneal contamination and postoperative resource utilization in children with complicated appendicitis. METHODS: Intraoperative findings were collected prospectively at a single children's hospital from 2012 to 2014. The degree of peritoneal contamination was categorized as either "localized" (confined to the right lower quadrant and pelvis) or "extensive" (extending to the liver). Imaging utilization, postoperative length of stay (pLOS), hospital cost, and readmission rates were compared between groups. RESULTS: Of 88 patients with complicated appendicitis, 38% had extensive contamination. Preoperative characteristics were similar between groups. Patients with extensive contamination had higher rates of postoperative imaging (58.8% vs 27.7%, P<0.01), a 50% longer median pLOS (6days [IQR 4-9] vs 4days [IQR 2-5], P=0.003), a 30% higher median hospital cost ($17,663 [IQR $12,564-$23,697] vs $13,516 [IQR $10,546-$16,686], P=0.004), and a nearly four-fold higher readmission rate (20.6% vs 5.6%, P=0.04) compared to children with localized contamination. CONCLUSION: Extensive peritoneal contamination is associated with significantly higher resource utilization compared to localized contamination in children with complicated appendicitis. These findings may have important severity-adjustment implications for reimbursement and readmission rate reporting for hospitals that serve populations where late presentation is common.

Diagnostic imaging practices for children with suspected appendicitis evaluated at definitive care hospitals and their associated referral centers.

PURPOSE: The purpose of this study was to compare rates of ultrasound (US) and computed tomography (CT) for suspected appendicitis at hospitals able to provide definitive surgical care with those from their associated referral hospitals. METHODS: A retrospective cohort study of children undergoing appendectomy using the Pediatric NSQIP Appendectomy Pilot Database (1/1/2013-8/31/2014) was performed. Imaging rates at the initial hospital of presentation were compared between groups after adjusting for differences in demographic characteristics. RESULTS: We identified 4859 patients from 28 definitive care hospitals, of which 35% underwent diagnostic imaging at a referral hospital prior to transfer (range: 20.3-70.4%). The overall odds of receiving a CT scan was 10.9-times greater (95% CI: 9.4-12.5) at referring hospitals compared to definitive care hospitals, and the odds were significantly higher for referral hospitals in 96% (27/28) of the geographic regions represented. The overall odds of an initial attempt at US prior to CT was 11.1 times greater (95% CI: 9.09-14.28), and the odds of receiving any ultrasound was 6.25-times greater (95% CI: 5.26-7.14) at definitive care hospitals compared to referral hospitals. CONCLUSIONS: Children initially evaluated for suspected appendicitis at referring hospitals are much more likely to receive a diagnostic CT, and those imaged with CT are much less likely to receive an US as the initial diagnostic test.

Use of White Blood Cell Count and Polymorphonuclear Leukocyte Differential to Improve the Predictive Value of Ultrasound for Suspected Appendicitis in Children.

BACKGROUND: The objective of this study was to examine the use of WBC count and polymorphonuclear leukocyte differential (PMN%) for improving the predictive value of ultrasound (US) in children with suspected appendicitis. STUDY DESIGN: We conducted a retrospective cohort study of children undergoing US for suspected appendicitis between January 1, 2010 and December 31, 2012 at a single children's hospital (n=845). Negative (NPV) and positive predictive values (PPV) for appendicitis were calculated for common constellations of US findings and compared with and without the use of laboratory thresholds (WBC>9×10(3)/µL and PMN%>65% for PPV; WBC≤9×10(3)/µL and PMN%≤65% for NPV). RESULTS: Fifty-one percent of US were considered "equivocal" (ie, appendix incompletely visualized, no primary or secondary signs, or presence of fluid only) and NPV increased significantly for this cohort using laboratory thresholds (41.9% vs 95.8%; p<0.001). Primary signs of appendicitis, without secondary signs, were documented in 18% of examinations, and the PPV associated with this cohort increased from 79.1% to 91.3% (p<0.001) using laboratory thresholds. Secondary signs with or without primary signs were documented in 24% of examinations, and laboratory thresholds improved the PPV in this cohort from 89.1% to 96.8% (p<0.001). Guidelines recommending against the use of CT for very high-risk and low-risk categories (NPV>95% and PPV>95%) on the basis of combined US and laboratory data could have reduced the number of CTs by 27.1% (101 of 373) during the study period. CONCLUSIONS: The incorporation of WBC count and PMN% can substantially improve the predictive value of US in the diagnosis of suspected appendicitis in children.

Brain edema predicts outcome after nonlacunar ischemic stroke.

BACKGROUND AND PURPOSE: In malignant infarction, brain edema leads to secondary neurological deterioration and poor outcome. We sought to determine whether swelling is associated with outcome in smaller volume strokes. METHODS: Two research cohorts of acute stroke subjects with serial brain MRI were analyzed. The categorical presence of swelling and infarct growth was assessed on diffusion-weighted imaging (DWI) by comparing baseline and follow-up scans. The increase in stroke volume (ΔDWI) was then subdivided into swelling and infarct growth volumes using region-of-interest analysis. The relationship of these imaging markers with outcome was evaluated in univariable and multivariable regression. RESULTS: The presence of swelling independently predicted worse outcome after adjustment for age, National Institutes of Health Stroke Scale, admission glucose, and baseline DWI volume (odds ratio, 4.55; 95% confidence interval, 1.21-18.9; P<0.02). Volumetric analysis confirmed that ΔDWI was associated with outcome (odds ratio, 4.29; 95% confidence interval, 2.00-11.5; P<0.001). After partitioning ΔDWI into swelling and infarct growth volumetrically, swelling remained an independent predictor of poor outcome (odds ratio, 1.09; 95% confidence interval, 1.03-1.17; P<0.005). Larger infarct growth was also associated with poor outcome (odds ratio, 7.05; 95% confidence interval, 1.04-143; P<0.045), although small infarct growth was not. The severity of cytotoxic injury measured on apparent diffusion coefficient maps was associated with swelling, whereas the perfusion deficit volume was associated with infarct growth. CONCLUSIONS: Swelling and infarct growth each contribute to total stroke lesion growth in the days after stroke. Swelling is an independent predictor of poor outcome, with a brain swelling volume of ≥11 mL identified as the threshold with greatest sensitivity and specificity for predicting poor outcome.