Frederick Thurston Drake

Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management

Acute appendicitis is one of the most common abdominal emergencies worldwide. The cause remains poorly understood, with few advances in the past few decades. To obtain a confident preoperative diagnosis is still a challenge, since the possibility of appendicitis must be entertained in any patient presenting with an acute abdomen. Although biomarkers and imaging are valuable adjuncts to history and examination, their limitations mean that clinical assessment is still the mainstay of diagnosis. A clinical classification is used to stratify management based on simple (non-perforated) and complex (gangrenous or perforated) inflammation, although many patients remain with an equivocal diagnosis, which is one of the most challenging dilemmas. An observed divide in disease course suggests that some cases of simple appendicitis might be self-limiting or respond to antibiotics alone, whereas another type often seems to perforate before the patient reaches hospital. Although the mortality rate is low, postoperative complications are common in complex disease. We discuss existing knowledge in pathogenesis, modern diagnosis, and evolving strategies in management that are leading to stratified care for patients.

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.

Time to Appendectomy and Risk of Perforation in Acute Appendicitis

IMPORTANCEnIn the traditional model of acute appendicitis, time is the major driver of disease progression; luminal obstruction leads inexorably to perforation without timely intervention. This perceived association has long guided clinical behavior related to the timing of appendectomy.nnnOBJECTIVEnTo evaluate whether there is an association between time and perforation after patients present to the hospital.nnnDESIGN, SETTING, AND PARTICIPANTSnUsing data from the Washington State Surgical Care and Outcomes Assessment Program (SCOAP), we evaluated patterns of perforation among patients (≥18 years) who underwent appendectomy from January 1, 2010, to December 31, 2011. Patients were treated at 52 diverse hospitals including urban tertiary centers, a university hospital, small community and rural hospitals, and hospitals within multi-institutional organizations.nnnMAIN OUTCOMES AND MEASURESnThe main outcome of interest was perforation as diagnosed on final pathology reports. The main predictor of interest was elapsed time as measured between presentation to the hospital and operating room (OR) start time. The relationship between in-hospital time and perforation was adjusted for potential confounding using multivariate logistic regression. Additional predictors of interest included sex, age, number of comorbid conditions, race and/or ethnicity, insurance status, and hospital characteristics such as community type and appendectomy volume.nnnRESULTSnA total of 9048 adults underwent appendectomy (15.8% perforated). Mean time from presentation to OR was the same (8.6 hours) for patients with perforated and nonperforated appendicitis. In multivariate analysis, increasing time to OR was not a predictor of perforation, either as a continuous variable (odds ratiou2009=u2009 1.0 [95% CI, 0.99-1.01]) or when considered as a categorical variable (patients ordered by elapsed time and divided into deciles). Factors associated with perforation were male sex, increasing age, 3 or more comorbid conditions, and lack of insurance.nnnCONCLUSIONS AND RELEVANCEnThere was no association between perforation and in-hospital time prior to surgery among adults treated with appendectomy. These findings may reflect selection of those at higher risk of perforation for earlier intervention or the effect of antibiotics begun at diagnosis but they are also consistent with the hypothesis that perforation is most often a prehospital occurrence and/or not strictly a time-dependent phenomenon. These findings may also guide decisions regarding personnel and resource allocation when considering timing of nonelective appendectomy.

ACGME case logs: Surgery resident experience in operative trauma for two decades.

BACKGROUND Surgery resident education is based on experiential training, which is influenced by changes in clinical management strategies, technical and technologic advances, and administrative regulations. Trauma care has been exposed to each of these factors, prompting concerns about resident experience in operative trauma. The current study analyzed the reported volume of operative trauma for the last two decades; to our knowledge, this is the first evaluation of nationwide trends during such an extended time line. METHODS The Accreditation Council for Graduate Medical Education (ACGME) database of operative logs was queried from academic year (AY) 1989–1990 to 2009–2010 to identify shifts in trauma operative experience. Annual case log data for each cohort of graduating surgery residents were combined into approximately 5-year blocks, designated Period I (AY1989–1990 to AY1993–1994), Period II (AY1994–1995 to AY1998–1999), Period III (AY1999–2000 to AY2002–2003), and Period IV (AY2003–2004 to AY2009–2010). The latter two periods were delineated by the year in which duty hour restrictions were implemented. RESULTS Overall general surgery caseload increased from Period I to Period II (p < 0.001), remained stable from Period II to Period III, and decreased from Period III to Period IV (p < 0.001). However, for ACGME-designated trauma cases, there were significant declines from Period I to Period II (75.5 vs. 54.5 cases, p < 0.001) and Period II to Period III (54.5 vs. 39.3 cases, p < 0.001) but no difference between Period III and Period IV (39.3 vs. 39.4 cases). Graduating residents in Period I performed, on average, 31 intra-abdominal trauma operations, including approximately five spleen and four liver operations. Residents in Period IV performed 17 intra-abdominal trauma operations, including three spleen and approximately two liver operations. CONCLUSION Recent general surgery trainees perform fewer trauma operations than previous trainees. The majority of this decline occurred before implementation of work-hour restrictions. Although these changes reflect concurrent changes in management of trauma, surgical educators must meet the challenge of training residents in procedures less frequently performed. LEVEL OF EVIDENCE Epidemiologic study, level III; therapeutic study, level IV.

The Clinical Education Partnership Initiative: an innovative approach to global health education

BackgroundDespite evidence that international clinical electives can be educationally and professionally beneficial to both visiting and in-country trainees, these opportunities remain challenging for American residents to participate in abroad. Additionally, even when logistically possible, they are often poorly structured. The Universities of Washington (UW) and Nairobi (UoN) have enjoyed a long-standing research collaboration, which recently expanded into the UoN Medical Education Partnership Initiative (MEPI). Based on MEPI in Kenya, the Clinical Education Partnership Initiative (CEPI) is a new educational exchange program between UoN and UW. CEPI allows UW residents to partner with Kenyan trainees in clinical care and teaching activities at Naivasha District Hospital (NDH), one of UoN’s MEPI training sites in Kenya.MethodsUW and UoN faculty collaborated to create a curriculum and structure for the program. A Chief Resident from the UW Department of Medicine coordinated the program at NDH. From August 2012 through April 2014, 32 UW participants from 5 medical specialties spent between 4 and 12xa0weeks working in NDH. In addition to clinical duties, all took part in formal and informal educational activities. Before and after their rotations, UW residents completed surveys evaluating clinical competencies and cross-cultural educational and research skills. Kenyan trainees also completed surveys after working with UW residents for three months.ResultsUW trainees reported a significant increase in exposure to various tropical and other diseases, an increased sense of self-reliance, particularly in a resource-limited setting, and an improved understanding of how social and cultural factors can affect health. Kenyan trainees reported both an increase in clinical skills and confidence, and an appreciation for learning a different approach to patient care and professionalism.ConclusionsAfter participating in CEPI, both Kenyan and US trainees noted improvement in their clinical knowledge and skills and a broader understanding of what it means to be clinicians. Through structured partnerships between institutions, educational exchange that benefits both parties is possible.

Enteral contrast in the computed tomography diagnosis of appendicitis: comparative effectiveness in a prospective surgical cohort.

Objective:Our goal was to perform a comparative effectiveness study of intravenous (IV)-only versus IV + enteral contrast in computed tomographic (CT) scans performed for patients undergoing appendectomy across a diverse group of hospitals. Background:Small randomized trials from tertiary centers suggest that enteral contrast does not improve diagnostic performance of CT for suspected appendicitis, but generalizability has not been demonstrated. Eliminating enteral contrast may improve efficiency, patient comfort, and safety. Methods:We analyzed data for adult patients who underwent nonelective appendectomy at 56 hospitals over a 2-year period. Data were obtained directly from patient charts by trained abstractors. Multivariate logistic regression was utilized to adjust for potential confounding. The main outcome measure was concordance between final radiology interpretation and final pathology report. Results:A total of 9047 adults underwent appendectomy and 8089 (89.4%) underwent CT, 54.1% of these with IV contrast only and 28.5% with IV + enteral contrast. Pathology findings correlated with radiographic findings in 90.0% of patients who received IV + enteral contrast and 90.4% of patients scanned with IV contrast alone. Hospitals were categorized as rural or urban and by their teaching status. Regardless of hospital type, there was no difference in concordance between IV-only and IV + enteral contrast. After adjusting for age, sex, comorbid conditions, weight, hospital type, and perforation, odds ratio of concordance for IV + enteral contrast versus IV contrast alone was 0.95 (95% CI: 0.72–1.25). Conclusions:Enteral contrast does not improve CT evaluation of appendicitis in patients undergoing appendectomy. These broadly generalizable results from a diverse group of hospitals suggest that enteral contrast can be eliminated in CT scans for suspected appendicitis.

Is there a need to standardize reporting terminology in appendicitis

While computed tomography (CT) remains the most accurate and widely used modality for appendicitis imaging, ultrasound has developed its own niche role, especially in the pediatric population and in premenopausal women. Ultrasound is commonly used as the initial imaging test when available, with indeterminate or clinically equivocal cases proceeding to CT.To avoid the radiation and time and cost of CT, ultrasound needs to be improved. While previous studies have focused on improving the diagnostic accuracy of ultrasound through better patient selection and technique, relatively little attention has been brought to the ultrasound report, which often serves as the sole mode of communication between the radiologist and the clinician.Standardization of reporting and terminology has been found to improve patient outcomes and management in breast imaging. A standardized report for appendicitis has the potential to decrease confusion and increase accuracy. A potential format could include a standardized list of the presence or absence of imaging findings associated with appendicitis, with a final summary or score indicating the likelihood of appendicitis being present. Aggregation of data over time through use of a common format could help guide radiologist recommendations based on which imaging findings are present. Overall, a standardized report could help increase the value of ultrasound, leading to improved radiologist-clinician communication, better patient outcomes, and decreased costs.

A Novel Reporting System to Improve Accuracy in Appendicitis Imaging

OBJECTIVEnThe purpose of this study was to ascertain if standardized radiologic reporting for appendicitis imaging increases diagnostic accuracy.nnnMATERIALS AND METHODSnWe developed a standardized appendicitis reporting system that includes objective imaging findings common in appendicitis and a certainty score ranging from 1 (definitely not appendicitis) through 5 (definitely appendicitis). Four radiologists retrospectively reviewed the preoperative CT scans of 96 appendectomy patients using our reporting system. The presence of appendicitis-specific imaging findings and certainty scores were compared with final pathology. These comparisons were summarized using odds ratios (ORs) and the AUC.nnnRESULTSnThe appendix was visualized on CT in 89 patients, of whom 71 (80%) had pathologically proven appendicitis. Imaging findings associated with appendicitis included appendiceal diameter (odds ratio [OR] = 14 [> 10 vs < 6 mm]; p = 0.002), periappendiceal fat stranding (OR = 8.9; p < 0.001), and appendiceal mucosal hyperenhancement (OR = 8.7; p < 0.001). Of 35 patients whose initial clinical findings were reported as indeterminate, 28 (80%) had appendicitis. In this initially indeterminate group, using the standardized reporting system, radiologists assigned higher certainty scores (4 or 5) in 21 of the 28 patients with appendicitis (75%) and lower scores (1 or 2) in five of the seven patients without appendicitis (71%) (AUC = 0.90; p = 0.001).nnnCONCLUSIONnStandardized reporting and grading of objective imaging findings correlated well with postoperative pathology and may decrease the number of CT findings reported as indeterminate for appendicitis. Prospective evaluation of this reporting system on a cohort of patients with clinically suspected appendicitis is currently under way.

The Reliability of a Standardized Reporting System for the Diagnosis of Appendicitis

PURPOSEnComputed tomography (CT) is a fast and ubiquitous tool to evaluate intra-abdominal organs and diagnose appendicitis. However, traditional CT reporting does not necessarily capture the degree of uncertainty and indeterminate findings are still common. The purpose of this study was to evaluate the reproducibility of a standardized CT reporting system for appendicitis across a large population and the systems impact on radiologists certainty in diagnosing appendicitis.nnnMETHODSnUsing a previously described standardized reporting system, eight radiologists retrospectively evaluated CT scans, blinded to all clinical information, in a stratified random sample of 237 patients from a larger cohort of patients imaged for possible appendicitis (2010-2014). Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to evaluate the diagnostic performance of readers for identifying appendicitis. Two-thirds of these scans were randomly selected to be independently read by a second reader, using the original CT reports to balance the number of positive, negative and indeterminate exams across all readers. Inter-reader agreement was evaluated.nnnRESULTSnThere were 113 patients with appendicitis (mean age 38, 67% male). Using the standardized report, radiologists were highly accurate at identifying appendicitis (AUC=0.968, 95%CI confidence interval: 0.95, 0.99. Inter-reader agreement was >80% for most objective findings, and certainty in diagnosing appendicitis was high and reproducible (AUC=0.955 and AUC=0.936 for the first and second readers, respectively).nnnCONCLUSIONSnUsing a standardized reporting system resulted in high reproducibility of objective CT findings for appendicitis and achieved high diagnostic accuracy in an at-risk population. Predictive tools based on this reporting system may further improve communication about certainty in diagnosis and guide patient management, especially when CT findings are indeterminate.