Current surgical opinion of computed tomography for acute appendicitis

Improvement in the diagnosis of appendicitis

Our attempts to systematically improve accuracy in the evaluation of patients with suspected appendicitis are, in some ways, hindered by the fact that the condition is so frequently straightforward to diagnose. Careful history-taking and physical examination are reliable in most patients. However, establishing the diagnosis with these skills alone remains vulnerable to conditions that masquerade as acute appendicitis. A substantial body of clinical research over the last quarter-century has shown that improved accuracy is possible. Strategies for improvement include the use of diagnostic scoring systems, laboratory makers such as CRP, diagnostic laparoscopy, and advanced imaging modalities such as CT, MRI, and US. How clinicians use these strategies depends on many factors related to practice setting, the population served, and clinical goals. In children, for instance, the desire to limit exposure to ionizing radiation competes with the greater anatomic detail that a CT scan can provide; at the same time, many hospitals that treat children do not have the resources to maintain the sort of full-time, highly sophisticated abdominal US programs that achieve the highest rates of diagnostic accuracy in clinical studies. Trade-offs have to be made, but improvement is possible in almost all groups of patients: the clinical community should no longer settle for a 15% NA rate when 5% is clearly possible without adverse consequences. Many clinicians will be faced with the task of evaluating patients suspected of having acute appendicitis. A deliberate, proactive, and, ideally, benchmarked strategy for improving diagnosis should be the standard to which we hold ourselves and the promise we deliver to our 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.

[Rational diagnostics of acute abdomen]

BACKGROUND

In view of the threat that comes with an acute abdomen, it is of major importance that diagnostics are executed quickly and efficiently. In the course of this two tendencies can be differentiated: 1) general use of complex examination (e.g. CT, MRT) of all potential patients and 2) step-by-step-diagnostics with advanced diagnostics as and when required.

MATERIAL AND METHODS

A total of 444 patients with an acute abdomen as admission diagnosis were investigated. All data were evaluated prospectively and analyzed retrospectively. All patients had the same basic diagnostics consisting of aclinical history, clinical examination, laboratory examination, abdominal sonography and x-ray overview images. These examinations were supplemented when required by advanced measures, such as CT, colon enema with contrast fluid, endoscopic examination and diagnostic laparotomy.

RESULTS

Three different disease groups of unequal diagnostic need could be identified. The first group, presented in the form of an appendicitis showed that in 80% of all patients a basic diagnosis was sufficient. Advanced examination such as CT affected 14%. The negative appendectomy rate amounted to 8%. Other diseases belonging to the first group were ileus, acute biliary diseases, perforation etc. In the second group presented in the form of a diverticulitis, an advanced radiological examination was required in 84% of all cases. Similar results are also expected in cases of pancreatitis. In the third group presented in the form of coprostasis, inflammatory etiology was found in 39% of all secondary diseases. However the symptoms became clinically apparent after treatment of the coprostasis. In this group a basic diagnosis was satisfactory in 84% of cases, however, a diagnostic laparotomy was inevitable for 3% of these patients.

CONCLUSION

Generally step-by-step diagnostic approach has proven itself to be efficient. For 80% of all patients it makes advanced diagnostic measures unnecessary. The exceptions are diseases in which it is necessary to know not only the diagnosis but also the disease stage. In these cases (e.g. pancreatitis, diverticulitis etc.) advanced diagnostics should be pursued from the onset. The necessity of a diagnostic laparotomy has lost importance for 1% of all patients.

Single and combined diagnostic value of clinical features and laboratory tests in acute appendicitis

OBJECTIVES

The objective was to evaluate the diagnostic accuracy of clinical features and laboratory test results in detecting acute appendicitis.

METHODS

Clinical features and laboratory test results were prospectively recorded in a consecutive series of 1,101 patients presenting with abdominal pain at the emergency department (ED) in six hospitals. Likelihood ratios (LRs) and the areas under the receiver operating characteristic curve (AUC) were calculated for the individual features. Variants of clinical presentation, based on different combinations of clinical features, were investigated and the accuracies of combinations of clinical features were evaluated.

RESULTS

The discriminative power (AUC) of the individual features in patients with suspected appendicitis ranged from 0.50 to 0.65. For five of the 23 predictor sets, the accuracy for appendicitis was more than 85%. This accuracy was only found in male patients. The relative frequency of these predictor sets ranged from 2% to 13% of patients with suspected appendicitis. A combination of the clinical features migration of pain to the right lower quadrant (RLQ), and direct tenderness in the RLQ, was present in only 28% (120/422) of clinically suspected patients, of whom no more than 85 patients had appendicitis (71%). A "classical" presentation (combination of migration of pain to the RLQ, tenderness in the RLQ, and rigidity) occurred in only 6% (25/422) of patients with suspected appendicitis and yielded an accuracy of 100% in males but only 46% in females.

CONCLUSIONS

The discriminative power (AUC) of individual clinical features and laboratory test results for appendicitis was weak in patients with suspected appendicitis. Combinations of clinical features and laboratory tests with high diagnostic accuracy are relatively infrequent in patients with suspected appendicitis.

Computed tomography-based clinical diagnostic pathway for acute appendicitis: prospective validation

BACKGROUND

Despite our regular use of CT for suspected appendicitis, a recent study at our institution demonstrated a negative appendectomy (NA) rate similar to our rate 15 years earlier. Based on analysis of this data, a diagnostic pathway was implemented prospectively for adult patients with possible appendicitis.

STUDY DESIGN

Rates of CT, NA, and perforation for nonpregnant patients over 14 years of age undergoing appendectomy between August 2001 and August 2002 (PRE) were compared with prospectively collected pathway data (PATH, August 2004 to August 2005). All PATH patients were evaluated by a surgeon before CT. All females underwent CT. CT was obtained in male patients with low suspicion or pain for longer than 48 hours. After negative CT, patients were discharged from the emergency department or admitted for observation.

RESULTS

There was a substantial decrease in NA rate after implementation of the pathway (4% PATH [8 of 183] versus 16% PRE [31 of 196], p < 0.001), without a change in the rate of perforation (11% PATH [20 of 175] versus 8% PRE [13 of 165], p = 0.28) or frequency of preoperative CT (59% PATH [108 of 183] versus 60% PRE [118 of 196], p = 0.84).

CONCLUSIONS

Frequent appendiceal CT alone does not ensure surgical diagnostic accuracy. CT need not be used in all patients to achieve very low NA rates. An evidence-based diagnostic algorithm incorporating early surgical evaluation, objective criteria for preoperative CT, deterrence of early operation after negative CT, and use of CT to facilitate safe discharge led to substantial improvements in the care of our adult population presenting with possible appendicitis.

Diagnosis and management of diverticulitis and appendicitis

Diverticulitis and appendicitis are common infections of the gastrointestinal tract that require urgent medical and surgical attention. Successful management of these conditions requires a multidisciplinary approach among primary care providers, gastroenterologists, surgeons, and radiologists. The diagnosis of appendicitis, in particular, can be difficult. Advances in radiographic imaging have improved the diagnostic accuracy in these infections. Minimally invasive surgical techniques have improved the patient's postoperative recovery when surgery is necessary in the management of these conditions.