An evidence-based clinical protocol for diagnosis of acute appendicitis decreased the use of computed tomography in children

Appendicitis Inflammatory Response Score in Acute Appendicitis: A Study at a Tertiary Care Center in North India

Introduction

Appendicitis is a common cause of acute abdominal pain. The diagnosis is eminently clinical and the cause is surgically correctable. However, a decision of surgery based on the clinical presentation only has a 15%-30% chance of the removal of a normal appendix. Thus, the diagnosis involves a corroboration of clinical, laboratory, and radiological findings. Appendicitis scoring systems can be considered to expedite the diagnostic and decision-making process.

Aim

The present study was conducted to study the efficacy of Appendicitis Inflammatory Response (AIR) score in the diagnosis of acute appendicitis and its correlation with the histopathological findings.

Materials and Methods

A cross-sectional study was conducted at a tertiary care center in North India comprising patients who presented to the surgery department with a provisional diagnosis of acute appendicitis and required appendectomy.

Results

Appendicitis was histopathologically proven in 54 patients. Patients with an AIR score ≥5 were 2.18 times more likely to have appendicitis. The probability of having appendicitis with AIR score ≥5 was 92.16% (positive predictive value). The diagnostic accuracy of AIR score was 82.81%.

Conclusion

AIR score has a high sensitivity and positive predictive value in the diagnosis of acute appendicitis. It is a quick and convenient system for clinical evaluation of patients in primary care or peripheral hospitals where advanced facilities such as USG scan or CT scan are not available all the time. The application of this scoring system definitely improves diagnostic accuracy and reduces negative appendectomy rate.

The use of a pediatric appendicitis pathway in a large integrated health system reduced computed tomography imaging in the ED

BACKGROUND

Appendicitis is the most common cause of an acute surgical abdomen in children. Diagnosis is often challenging as few pediatric patients present with classic symptoms. Clinicians are thus dependent on imaging to reach an accurate diagnosis. Although computerized tomography (CT) has high sensitivity and specificity, it has the disadvantage of imparting ionizing radiation. Ultrasound (US) is readily available and has comparable accuracy to CT when performed by experienced sonographers. We sought to examine the impact of a system-wide process improvement plan on CT use and other metrics in pediatric patients who presented to the Emergency Department (ED) with suspected appendicitis.

METHODS

This is a retrospective study of the impact of a Pediatric Appendicitis Pathway (PAP) within a large integrated hospital system with 12 EDs including 3 designated hub EDs. Patients were placed in an initial risk category utilizing the Pediatric Appendicitis Score (PAS), and received US of the appendix at a hub ED if indicated by the PAS. Patients presenting to community EDs who required US appendix were transferred to hub EDs for imaging. Patients presenting in the 6-month pre-implementation period were compared to patients presenting in a 14-month post-implementation period on CT and US utilization, negative and missed appendectomy rates, and ED length of stay (LOS).

RESULTS

1874 patients (401 pre-PAP and 1473 post-PAP) were included in the study. At the hub EDs the rate of CT imaging for suspected appendicitis was reduced from 31% to 17% with a resultant increase in US utilization from 83% (333/401) to 90% (1331/1473) (p < 0.001). At community general EDs (404 pre-PAP and 449 post-PAP), the rate of CT was decreased from 45% (181/404) to 32%(144/449) (p < 0.001)) There was no significant change in the negative appendectomy rate pre-PAP (1/59 = 1.7%) and post-PAP (4/168 = 2.4%) (p = 0.99) at the hub EDs. There were no missed appendicitis cases after PAP implementation compared to 1 case in the pre-PAP period. Overall LOS was similar pre and post-PAP, however LOS was longer in patients that required transfer from community general EDs to hub EDs (median 264 vs 342 min, p < 0.001).

CONCLUSIONS

A PAP that stratified patients into risk groups using the PAS and encouraged the use of US as a first line imaging modality, reduced the number of CT performed in a large integrated health system without significant changes to clinical outcomes. Furthermore, transferring select patients for an US as opposed to obtaining an initial CT in community general EDs was feasible and reduced CT use in the pediatric population.

Prospective Validation of the APPEND Clinical Prediction Rule for Appendicitis: A Cohort Study

BACKGROUND

Right iliac fossa (RIF) pain is a common referral to general surgery as acute appendicitis is one of the most common underlying diagnoses. The clinical diagnosis of appendicitis continues to challenge clinicians. Clinical prediction rules (CPRs) are one method used to improve diagnostic accuracy and reduce negative appendicectomy rates. The APPEND score is a novel CPR that was developed at Middlemore Hospital.

AIM

To prospectively evaluate the performance of the APPEND CPR within a pathway dedicated to the management of RIF pain.

METHODS

A comparative cohort study of the clinical pathway incorporating the APPEND CPR pain was performed from January to July 2016. This was compared to the retrospective cohort used to develop the APPEND CPR. The primary end point was negative appendicectomy rate.

RESULTS

The negative appendicectomy rate in the prospective cohort was 9.2% (95% CI: 5.3%, 13.2%) compared to 19.8% (CI 16.2, 23.4%) in the retrospective cohort that did not use the APPEND CPR. After adjusting for multiple variables, the odds ratio of a negative appendicectomy was 2.33 times higher (95% CI; 1.26, 4.3, P value 0.007) in the retrospective cohort compared to the prospective cohort. An APPEND score of ≥5 was 87 % specific for ruling in appendicitis (PPV 94%) and a score of ≥1 was 100% sensitive in ruling out appendicitis (NPV 100%).

CONCLUSIONS

In a comparative cohort study of an RIF pain pathway incorporating the APPEND CPR, the rate of negative appendicectomy showed a significant reduction by more than 50%.

Does time of surgery influence the rate of false-negative appendectomies? A retrospective observational study of 274 patients

Background

Multiple disciplines have described an “after-hours effect” relating to worsened mortality and morbidity outside regular working hours. This retrospective observational study aimed to evaluate whether diagnostic accuracy of a common surgical condition worsened after regular hours.

Methods

Electronic operative records for all non-infant patients (age > 4 years) operated on at a single centre for presumed acute appendicitis were retrospectively reviewed over a 56-month period (06/17/2012–02/01/2017). The primary outcome measure of unknown diagnosis was compared between those performed in regular hours (08:00–17:00) or off hours (17:01–07:59). Pre-clinical biochemistry and pre-morbid status were recorded to determine case heterogeneity between the two groups, along with secondary outcomes of length of stay and complication rate.

Results

Out of 289 procedures, 274 cases were deemed eligible for inclusion. Of the 133 performed in regular hours, 79% were appendicitis, compared to 74% of the 141 procedures performed off hours. The percentage of patients with an unknown diagnosis was 6% in regular hours compared to 15% off hours (RR 2.48; 95% CI 1.14–5.39). This was accompanied by increased numbers of registrars (residents in training) leading procedures off hours (37% compared to 24% in regular hours). Pre-morbid status, biochemistry, length of stay and post-operative complication rate showed no significant difference.

Conclusions

This retrospective study suggests that the rate of unknown diagnoses for acute appendicitis increases overnight, potentially reflecting increased numbers of unnecessary procedures being performed off hours due to poorer diagnostic accuracy. Reduced levels of staffing, availability of diagnostic modalities and changes to workforce training may explain this, but further prospective work is required. Potential solutions may include protocolizing the management of common acute surgical conditions and making more use of non-resident on call senior colleagues.

Imaging Gently

Advances in medical imaging are invaluable in the care of pediatric patients in the emergent setting. The diagnostic accuracy offered by studies using ionizing radiation, such as plain radiography, computed tomography, and fluoroscopy, are not without inherent risks. This article reviews the evidence supporting the risk of ionizing radiation from medical imaging as well as discusses clinical scenarios in which clinicians play an important role in supporting the judicious use of imaging studies.

Overuse of CT and MRI in paediatric emergency departments

The aim of this review is to survey CT and MRI overuse in the paediatric emergency department (ED) population. CT is one of the most important modalities employed in the ED. Not surprisingly, its high accuracy, rapid acquisition and availability have resulted in overuse. An obvious limitation of CT is ionizing radiation; in addition there are economic implications to overuse. Studies from the last two decades have shown increase in paediatric ED CT utilization in the first decade, reaching a plateau forming around 2008, followed by a decrease in the last decade. This decrease occurred in conjunction with campaigns raising awareness to the risks of radiation exposure. Although a trend of decrease in overuse have been observed, great variability has been shown across different facilities, as well as among physicians, with more pronounced overuse in non-teaching and non-children dedicated EDs. The leading types of paediatric ED CTs are head and abdominal scans. Decision rules, such as PECARN for head injury and the Alvarado score for abdominal pain, as well as using alternative imaging modalities, have been shown to reduce CT overuse in these two categories. MRI has the obvious benefit of avoiding radiation exposure, but the disadvantages of higher costs, less availability and less tolerability in younger children. Although anecdotally paediatric ED MRI usage has increased in recent years, only scarce reports have been published. In our opinion, there is need to conduct up-to-date studies covering paediatric CT and MRI overuse trends, usage variability and adherence to clinical protocols.

Approaching zero: Implications of a computed tomography reduction program for pediatric appendicitis evaluation

PURPOSE

Because of awareness of iatrogenic radiation exposure, there is a national trend of diminishing computed tomography (CT) use for pediatric suspected appendicitis. The purpose of this study was to evaluate the effects of a CT reduction program for evaluation of appendicitis.

METHODS

A multidisciplinary group (emergency medicine, radiology, and surgery) at a children's hospital developed a reduction program which included: ultrasound (U/S) first (2012), magnetic resonance imaging (MRI) second (2014), and standardized U/S reports (2016). Imaging modality, negative appendectomy rate, time from first image to incision, and imaging costs were evaluated over time.

RESULTS

Of the 571 patients evaluated from 2012 to 2016, there was a significant decrease in CT use and increase U/S and MRI use over the study period (all p<0.01). CT use approached zero in 2016. Time from first image to incision (median 10.7h, IQR 5.6-15.5) and negative appendectomy rate (mean 3.7±0.2%) did not change. Median imaging costs ($88, IQR $52-$169) and radiology percent of total costs (range 0.8%-3.9%) increased over time (both p<0.01).

CONCLUSION

Approaching zero CT use for evaluation of pediatric appendicitis is possible through a multidisciplinary protocol without impacting clinical outcomes. However, increased MRI use led to higher costs. Cost-effectiveness of replacing CT with MRI warrants further study.

TYPE OF STUDY

Retrospective comparative study.

LEVEL OF EVIDENCE

Level III.

Admission levels of serum amyloid a and procalcitonin are more predictive of the diagnosis of acute appendicitis compared with C-reactive protein

BACKGROUND

Acute appendicitis is the commonest surgical emergency, but its diagnosis can be elusive with a negative appendicectomy rate of 20%. The aims of this study were to investigate the potential value of the markers of acute inflammation, serum amyloid A (SAA), and serum procalcitonin (ProCT), in the diagnosis of acute appendicitis in adults and to compare that with the commonly used serum C-reactive protein (CRP).

METHODS

Adult patients presenting with acute right lower abdominal pain and a clinical suspicion of acute appendicitis were included. Blood samples were obtained within 6 hours of admission for rapid serum CRP assay and for end-of-recruitment batch analysis of SAA and serum ProCT concentrations.

RESULTS

A total of 147 patients (81 males) with a mean (±SD) age of 36 (±17) years were recruited. Appendicitis was confirmed histologically in 61 of 72 patients (84.7%) who underwent appendicectomy. A post hoc analysis revealed a diagnostic sensitivity and specificity for SAA of 92% and 72%, ProCT of 85% and 74%, and CRP of 75% and 72%, respectively. The receiver operator characteristics for the area under the curves showed that SAA (P=0.011) and ProCT (P=0.037) significantly exceeded CRP in the prediction of acute appendicitis on admission.

CONCLUSIONS

The measurement of SAA and serum ProCT on admission in patients with clinically suspected acute appendicitis seems to outperform serum CRP in aiding that diagnosis.

Protocol for suspected pediatric appendicitis limits computed tomography utilization

BACKGROUND

Despite radiation concerns, computed tomography (CT) remains the favored imaging modality at many children's hospitals for appendicitis. We sought to reduce CT utilization for appendicitis in a children's hospital with an algorithm relying on 24-h ultrasound (US) as the primary imaging study.

MATERIALS AND METHODS

An US-based protocol for suspected appendicitis was adopted at the end of the fiscal year (FY) 2011. Data were collected for 12 mo before and 24 mo after implementation. Imaging test usage and charges were adjusted per annual number of appendectomies. Training of emergency department staff continued over 1 y after protocol implementation.

RESULTS

For FY 2011, 644 abdominal CT and 1088 appendix US were ordered, and 249 laparoscopic appendectomies (LAs) were performed. After protocol implementation, FY 2012: 535 CT, 1285 US, and 265 LA were performed; and FY 2013: 330 CT, 1235 US, and 236 LA were performed. Length of stay decreased from before to after protocol (2.57 ± 0.29 versus 2.15 ± 0.11 d), P < 0.001. CTs per appendectomy decreased 42% from FY 2011 to FY 2013 (2.43 versus 1.40, P < 0.001) and 30% from before to after protocol (2.43 versus 1.70, P < 0.001). A corresponding 27% increase in number of US before to after protocol (4.11 versus 5.20 US/appendectomy, P = 0.004) occurred. CT and US charges decreased $2253 and $6633 per appendectomy for FY 2012 and 2013, respectively.

CONCLUSIONS

Protocol-driven workup with US significantly reduced CT utilization, radiation exposure, and imaging-related charges in children with suspected appendicitis. Ongoing training of emergency department staff is required to ensure protocol compliance.

Diagnostic imaging for acute appendicitis: interfacility differences in practice patterns

PURPOSE

To evaluate trends and factors associated with interfacility differences in imaging modality selection in the diagnosis and management of children with suspected acute appendicitis.

METHODS

We conducted a retrospective review of diagnostic imaging selection and outcomes in patients <20 years of age who underwent appendectomy at a single Children's Hospital from June 2008 to June 2013. These results were then compared with those of referring hospitals.

RESULTS

A total of 232 children underwent appendectomy during the study period. Imaging results contributed to diagnostic and management decisions in 95.3 % of cases. CT scan was utilized as first-line imaging in 50 % of cases. CTs were preferentially performed at referring institutions (78 vs. 46 %, p < 0.001). Children were five times more likely to undergo CT at referring institutions (OR = 5.5, CI 3.0-10.2). Adjusting for demographics and Alvarado score, diagnostic imaging choice was independent of patient's clinical status.

CONCLUSION

This study demonstrates that initial presentation to a referring hospital independently predicts the use of CT scan for suspected acute appendicitis. Further efforts should be undertaken to develop a clinical pathway that minimizes radiation exposure in the diagnosis of acute appendicitis, with focus on access to pediatric abdominal ultrasound.

A model predicting perforation and complications in paediatric appendicectomy

PURPOSE

To analyse the diagnostic value of simple clinical measurements in ensuring an early and accurate detection of advanced appendicitis (perforation, mass and peri-appendicular abscess) and possible complications.

METHODS

A retrospective, single-centre study of all paediatric (age 0-14 years) appendicectomies was conducted over a 14-year period. Preoperative symptoms, signs and laboratory results, intra-operative findings and postoperative complications were analyzed. Receiver operating characteristic (ROC) curves were used to estimate sensitivity and specificity of significant (p ≤ 0.05) predictor variables based on multivariate logistic regression models.

RESULTS

One thousand and thirty-seven patients were included. Perforations were seen in 88 (8.5%) cases, and abscesses were seen in 35 (3.4%) cases. Of all the clinical variables evaluated, preoperative temperature ≥37.5 °C was most discriminatory for advanced appendicitis. Significant other discriminatory clinical variables were WBC count ≥15,100/μL, preoperative anorexia and rebound tenderness. Postoperative complications occurred in 74 (7.1%) patients and were associated with pre-operative temperature ≥37.5 °C and advanced appendicitis.

CONCLUSION

Independent clinical predictors of advanced appendicitis exist but lack individual accuracy. In this study, preoperative pyrexia is shown to be highly associated with both advanced appendicitis and development of postoperative complications. This independent factor may point to early need for antibiotic treatment, urgent imaging and subsequent intervention in patients with appendicitis.

Reducing computed tomography scans for appendicitis by introduction of a standardized and validated ultrasonography report template

PURPOSE

Computed tomography (CT) for the diagnosis of appendicitis is associated with radiation exposure and increased cost. In an effort to reduce the diagnostic use of CT scans, we implemented a standardized ultrasound report template based on validated secondary signs of appendicitis.

METHODS

In September 2012, as part of a quality improvement project, we developed and introduced a four category standardized ultrasound report template for limited right lower quadrant abdominal ultrasounds. Outcomes for patients undergoing ultrasound or CT scan for appendicitis between 9/10/2012 and 12/31/2013 (Period 2, n=2033) were compared to the three months prior to implementation (Period 1, n=304).

RESULTS

In Period 1, 78 of 304 (25.7%) patients had appendicitis versus 385 of 2033 (18.9%) in Period 2 (p=0.006). Non-diagnostic exams decreased from 48% to 0.1% (p<0.001). Ultrasound sensitivity improved from 66.67% to 92.2% (p<0.001). Specificity did not significantly change (96.9% to 97.69%, p=0.46). CT utilization for appendicitis decreased from 44.3% in Period 1 to 14.5% at the end of Period 2 (p<0.001).

CONCLUSIONS

Implementation of a standardized ultrasound report template based on validated secondary signs of appendicitis nearly eliminated non-diagnostic exams, improved diagnostic accuracy, and resulted in a striking decrease in CT utilization.

A simple algorithm reduces computed tomography use in the diagnosis of appendicitis in children

BACKGROUND

A diagnostic algorithm for appendicitis in children was created to reduce computed tomography (CT) use owing to the risk of cancer from radiation exposure and cost of CT. This study evaluates the impact of the algorithm on CT use and diagnostic accuracy of appendicitis.

METHODS

Patients ≤18 years who underwent appendectomy for suspected appendicitis after presenting to the emergency department for 2 years before and 3 years after algorithm implementation were identified. Clinical characteristics and outcomes, including use of CT and negative appendectomy rate, were compared between the pre- and post-implementation periods. Multivariable analysis was used to determine the impact of CT on negative appendectomy.

RESULTS

We identified 331 patients-41% in the pre- and 59% in the post-implementation period. CT utilization decreased from 39% to 18% (P < .001) after implementation. The negative appendectomy rate increased from 9% to 11% (P = .59). Use of CT did not impact the risk of negative appendectomy (P = .64).

CONCLUSION

Utilization of CT was significantly reduced after implementation of a diagnostic algorithm for appendicitis without impacting diagnostic accuracy. Given the concern for increased risk of cancer after CT, these results support use of an algorithm in children with suspected appendicitis.

Utility of CT after sonography for suspected appendicitis in children: integration of a clinical scoring system with a staged imaging protocol

To improve diagnosis of pediatric appendicitis, many institutions have implemented a staged imaging protocol utilizing ultrasonography (US) first and then computed tomography (CT). A substantial number of children with suspected appendicitis undergo CT after US, and the efficient and accurate diagnosis of pediatric appendicitis continues to be challenging. The objective of the study is to characterize the utility of CT following US for diagnosis of pediatric appendicitis, in conjunction with a clinical appendicitis score (AS). Imaging studies of children with suspected appendicitis who underwent CT after US in an imaging protocol were retrospectively reviewed by three radiologists in consensus. Chart review derived the AS (range 0-10) and obtained the patient diagnosis and disposition, and an AS was applied to each patient. Clinical and radiologic data were analyzed to assess the yield of CT after US. Studies of 211 children (mean age 11.3 years) were included. The positive threshold for AS was determined to be 6 out of 10. When AS and US were concordant (N = 140), the sensitivity and specificity of US were similar to CT. When AS and US were discordant (N = 71) and also when AS ≥ 6 (N = 84), subsequent CT showed superior sensitivity and specificity to US alone. In the subset where US showed neither the appendix nor inflammatory change in the right lower quadrant (126/211, 60 % of scans), when AS < 6 (N = 83), the negative predictive value (NPV) of US was 0.98. However, when AS ≥ 6 (N = 43), NPV of US was 0.58, and the positive predictive value of subsequent CT was 1. There was a significant decrease in depiction of the appendix on US with patient weight-to-age ratio of >6 (kg/year, P < 0.001) and after-hours (1700 -0730 hours) performance of US (P < 0.001). Results suggest that the appendicitis score has utility in guiding an imaging protocol and support the contention that non-visualization of the appendix on US is not intrinsically non-diagnostic. There was little benefit to additional CT when AS < 6 and US did not show the appendix or evidence of inflammation; this would have avoided CT in 140/211 (66 %) patients. CT demonstrated benefit when AS ≥ 6, suggesting that cases with AS ≥ 6 and features that limit depiction of the appendix on US may be triaged to CT.

Emergency medicine physicians' and pediatricians' use of computed tomography in the evaluation of pediatric patients with abdominal pain without trauma in a community hospital

There is a paucity of data regarding emergency department (ED) provider type and computed tomography (CT) scan use in the evaluation of pediatric patients with abdominal pain without trauma. The purpose of this retrospective single community hospital study was to determine if there was a difference in CT use between emergency medicine physicians (EMPs) and pediatricians (PEDs) in all patients younger than 18 years with abdominal pain without trauma who presented to the ED during the study period. The study included 165 patients. EMPs saw 83 patients and used CT in 31 compared with PEDs who saw 82 patients and used CT in 12 (P = .002). EMPs used CT significantly more frequently than PEDs in the designated sample. Economic pressures may cause changes in ED provider type in community and rural hospitals and this study shows that ED provider type may affect medical decision making, including CT use.

Clinical practice guidelines for pediatric appendicitis evaluation can decrease computed tomography utilization while maintaining diagnostic accuracy

OBJECTIVES

The objective of this study was to compare usage of computed tomography (CT) scan for evaluation of appendicitis in a children's hospital emergency department before and after implementation of a clinical practice guideline focused on early surgical consultation before obtaining advanced imaging.

METHODS

A multidisciplinary team met to create a pathway to formalize the evaluation of pediatric patients with abdominal pain. Computed tomography scan utilization rates were studied before and after pathway implementation.

RESULTS

Among patients who had appendectomy in the year before implementation (n = 70), 90% had CT scans, 6.9% had ultrasound, and 5.7% had no imaging. The negative appendectomy rate before implementation was 5.7%. In patients undergoing appendectomy in the postimplementation cohort (n = 96), 48% underwent CT, 39.6% underwent ultrasound, and 15.6% had no imaging. The negative appendectomy rate was 5.2%. We demonstrated a 41% decrease in CT use for patients undergoing appendectomy at our institution without an increase in the negative appendectomy rate or missed appendectomy. The results were even more striking when comparing the rate of CT scan use in the subset of patients undergoing appendectomy without imaging from an outside hospital. In these patients, CT scan utilization decreased from 82% to 20%, a 76% reduction in CT use in our facility after protocol implementation.

CONCLUSIONS

Implementation of a clinical evaluation pathway emphasizing examination, early surgeon involvement, and utilization of ultrasound as the initial imaging modality for evaluation of abdominal pain concerning for appendicitis resulted in a marked decrease in the reliance on CT scanning without loss of diagnostic accuracy.

On the Role of Ultrasonography and CT Scan in the Diagnosis of Acute Appendicitis

The purposes of this study were to revisit the utility of ultrasonography (USG) as a primary imaging modality in acute appendicitis (AA) and to establish the role of CT scan as a second-line/problem-solving modality. All cases of suspected AA were referred for urgent USG. USG was done with standard protocol for appendicitis. Limited computed tomographic (CT) scan [NCCT ± CECT (IV contrast only)] was done for the lower abdomen and pelvis where sonographic findings were equivocal. One hundred and twenty-one patients were referred for USG for suspected appendicitis. Eight-four patients underwent surgery for AA based on clinical as well as imaging findings, of whom 76 had appendicitis confirmed at histopathology. Three patients were misdiagnosed (3.6 %) on USG as appendicitis. Of 76 patients of appendicitis confirmed histopathologically, 63 (82.8 %) had features of appendicitis on USG and did not require any additional imaging modality. Of 121 patients, 12 (10 %) needed CT scan because of atypical features on USG. Of these 12 patients, seven had retrocecal appendicitis, and three high-up paracolic appendicitis. USG alone had sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 81, 88, 92.6, 71.6, and 83 %, respectively. When combined with CT scan in select cases, the sensitivity, specificity, PPV, NPV, and accuracy of combined USG + CT scan were 96 % (P = 0.0014), 89 %, 93 %, 93.5 % (P = 0.0001), and 93 % (P = 0.0484), respectively. Twenty-eight (23 %) patients were given alternative diagnosis on USG. Dedicated appendiceal USG should be used as a primary imaging modality in diagnosing or excluding AA. Appendiceal CT can serve as a problem-solving modality.

Progress in the diagnosis of appendicitis: a report from Washington State's Surgical Care and Outcomes Assessment Program

BACKGROUND AND OBJECTIVES

Studies suggest that computed tomography and ultrasonography can effectively diagnose and rule out appendicitis, safely reducing negative appendectomies (NAs); however, some within the surgical community remain reluctant to add imaging to clinical evaluation of patients with suspected appendicitis. The Surgical Care and Outcomes Assessment Program (SCOAP) is a physician-led quality initiative that monitors performance by benchmarking processes of care and outcomes. Since 2006, accurate diagnosis of appendicitis has been a priority for SCOAP. The objective of this study was to evaluate the association between imaging and NA in the general community.

METHODS

Data were collected prospectively for consecutive appendectomy patients (age > 15 years) at nearly 60 hospitals. SCOAP data are obtained directly from clinical records, including radiological, operative, and pathological reports. Multivariate logistic regression models were used to examine the association between imaging and NA. Tests for trends over time were also conducted.

RESULTS

Among 19,327 patients (47.9% female) who underwent appendectomy, 5.4% had NA. Among patients who were imaged, frequency of NA was 4.5%, whereas among those who were not imaged, it was 15.4% (P < 0.001). This association was consistent for men (3% vs 10%, P < 0.001) and for women of reproductive age (6.9% vs 24.7%, P < 0.001). In a multivariate model adjusted for age, sex, and white blood cell count, odds of NA for patients not imaged were 3.7 times the odds for those who received imaging (95% CI: 3.0-4.4). Among SCOAP hospitals, use of imaging increased and NA decreased significantly over time; frequency of perforation was unchanged.

CONCLUSIONS

Patients who were not imaged during workup for suspected appendicitis had more than 3 times the odds of NA as those who were imaged. Routine imaging in the evaluation of patients suspected to have appendicitis can safely reduce unnecessary operations. Programs such as SCOAP improve care through peer-led, benchmarked practice change.

Sonography for appendicitis: nonvisualization of the appendix is an indication for active clinical observation rather than direct referral for computed tomography

PURPOSE

To determine the prevalence of perforated and nonperforated appendicitis in patients with nonvisualization of the appendix on ultrasound (US) performed for suspected appendicitis, and to evaluate the value of CT in these patients.

METHODS

We analyzed 400 consecutive patients undergoing US for suspected appendicitis. Of these patients, 260 had nonvisualization of the appendix, but otherwise normal scans. We analyzed the clinical outcome in these patients to determine the prevalence of appendicitis, referrals for CT, and the contribution of CT in these patients.

RESULTS

Of the 400 patients, 140 (35%) had either a normal (80 patients, 25%) or an abnormal appendix (60 patients, 15%); 260 (65%) had nonvisualization of the appendix. Overall 75 patients had appendicitis (18.8%) and 17 (4.3%) had appendicitis with perforation. Of the 260 patients with nonvisualization of the appendix, 14 patients (5.4%) had appendicitis and 2 were perforated (0.8%). The prevalence of perforated and nonperforated appendicitis in this group was significantly lower than the overall group (p < 0.001 and p < 0.01, respectively). Of these 260 patients, 101 patients (38.8%) had CT within 48 hours and 79 (78.2%) had normal scans.

CONCLUSIONS

Patients with nonvisualization of the appendix on US, but otherwise normal scans, are at significantly lower risk for appendicitis, either perforated or nonperforated. Active clinical observation should be considered in these patients, rather than direct referral for CT.

Computerized Tomography in the Workup of Pediatric Appendicitis: Why are Children Scanned?

Physicians increasingly use computerized tomography (CT) for the evaluation of suspected acute appendicitis (AA) in children despite increasing awareness of the potential dangers of CT-associated radiation exposure. Many studies demonstrate the value of CT in the diagnosis of AA, but none have determined what factors influence the decision to perform a CT. We investigated factors associated with the use of CT during initial workup of children who subsequently underwent appendectomy. This is a retrospective review of all patients aged 0 to 17 years who underwent appendectomy for AA by pediatric surgeons over 11 years. Both univariate and multivariable logistic regression models were created to predict use of CT. A total of 546 children underwent appendectomy for AA, of which 293 (53%) underwent CT. In univariate analysis, seven variables were significantly associated with the use of CT: female gender, Hispanic ethnicity, initial presentation to referring hospitals, lower Alvarado scores, delays from onset of symptoms to hospital presentation, migration, and rebound tenderness. In multivariable analysis, four variables significantly independently predicted the use of CT: initial presentation to a referring hospital [odds ratio (OR) 3.50), female gender (OR 1.49), increased latency from symptom onset to presentation (OR 1.34), and the presence of rebound tenderness (OR 0.23), which had a protective effect; the overall model was statistically significant ( P < 0.0001). This model is the first to define variables that significantly predict CT utilization in the pediatric population. Continued investigation will be necessary to develop effective algorithms for judicious use of CT for suspected AA.