Predicting negative appendectomy by using demographic, clinical, and laboratory parameters: A cross-sectional study

Adult appendicitis score versus Alvarado score: A comparative study in the diagnosis of acute appendicitis

Background

Acute Appendicitis (AA) is the most common abdominal surgical emergency. It requires proper management to decrease mortality and morbidity. Clinical scoring systems for diagnosing AA aimed to decrease the use of radiological scans and the rate of negative appendectomies (NA). We aim to assess the adult appendicitis score (AAS) in the diagnosis prediction of AA.

Method

A retrospective study with 1303 cases of AA is performed. We compared the correlation of AAS and Alvarado scores to postoperative histopathology. Specificity, sensitivity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) were assessed. ROC was used.

Results

AAS risk stratification was applied to the study population. Group I for a low probability, and groups II and III for an intermediate and high probability of AA. We found that 159 patients were matched in group I, 505, and 639 were in groups II and III of AAS, respectively. The correlation between Alvarado and AAS with HP was significant. AAS ≥ 16 presented sensitivity and specificity of 50 % and 75.47 %, respectively, with PPV of 97.96 % and NPV of 6.02 %, with an accuracy of 51.04 %. Regarding AAS ≥ 11, the sensitivity was 88.96 %, specificity was 39.62 %, PPV was 97.2 %, NPV was 13.21 %, and accuracy was 86.95 %.

Conclusion

AAS is relatively more accurate than Alvarado's score, especially in selecting a safe candidate for discharge from an emergency. In addition, AAS is found to decrease the need for radiological images and NA rate more than Alvarado.

Diagnostic accuracy of Alvarado scoring system relative to histopathological diagnosis for acute appendicitis: A retrospective cohort study

Background

Acute appendicitis (AA) is a surgical emergency that requires prompt diagnosis and suitable management. It may lead to complications resulting in mortality. To evaluate the diagnostic accuracy of the Alvarado scoring system (ASS) for acute appendicitis concerning histopathological data.

Methodology

About 120 patients were selected for this study consisting of 96 males and 24 females age between 20 and 60. Alvarado scoring system is calculated for each patient after collecting data about demographics, laboratory findings, and clinical examination. Then, we compared it with histopathological diagnosis taking it as a gold standard. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. SPSS version 20 was used for analyzing the data.

Results

About 120 patients were included in our study. The male to female ratio was 3:1. Sensitivity and specificity were 83.3% and 41% respectively. While PPV and NPV were 85% and 41% respectively. The negative appendectomy rate was 21%. The area under the curve for receiving operating characteristics is 0.628.

Conclusion

ASS is a useful diagnostic tool regarding sensitivity and positive predictive value, especially in developing countries. It is cheap, reliable, and can be easily applied.

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We evaluated the diagnostic accuracy of the Alvarado scoring system (ASS) for acute appendicitis.

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Sensitivity and specificity were 83.3% and 41%.

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While PPV and NPV were 85% and 41% respectively.

The Role of Alvarado Score in Predicting Acute Appendicitis and Its Severity in Correlation to Histopathology: A Retrospective Study in a Qatar Population

Background/objective

Acute appendicitis (AA) is one of the most common surgical emergencies that require a proper diagnosis to avoid a negative outcome in the case of missed or delayed diagnosis. Our study aims to assess the diagnostic power of the Alvarado score and the prediction of the severity of acute appendicitis in correlation to intraoperative findings and the final histopathology (HP) result.

Methods

This retrospective study was applied to 1,303 patients with clinically proven acute appendicitis (AA) and available HP results. We correlated Alvarado score to the gold standard HP and intraoperative findings. We selected the cutoff point of Alvarado at 5 and 7 as they were the most frequent cutoff value mentioned in the literature and based on the ROC curve in this study to assess sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Results

The mean age of the study cohort is 33.3 ± 9.5 years, with a male predominance (75.8%). The negative appendectomy (NA) rate was 4%. The operative complication rate was 1.2%, and we recorded one mortality case (0.1%). The diagnostic evidence of AA was in 95.9% of cases. Alvarado score ≥ 7 presented sensitivity and specificity of 66.4% and 69.8%, respectively, with PPV of 98.1% and NPV of 8.1%, with an accuracy of 66.5%. For Alvarado score ≥ 5, the sensitivity was 91.2%, specificity was 22.6%, PPV was 96.5%, NPV was 9.8%, and accuracy was 88.4%. In addition, we demonstrated statistical significance between Alvarado risk stratification with HP and intraoperative grades (p = 0.001 each).

Conclusion

The Alvarado scoring system alone is not enough to diagnose AA with unsatisfactory sensitivity and specificity. However, it is a good indicator of the severity of AA that we can depend on to prioritize those patients waiting for surgery.

Negative Appendicectomy Rate: Incidence and Predictors

Introduction

Acute appendicitis is a common emergency surgical presentation. The gold standard treatment is surgery. Like any surgical procedure, appendicectomy is associated with complications. Negative appendicectomy (NA) can occur, and its incidence is 15%-39%. This study aimed to evaluate the rate and predictors of NA in a cohort.

Patients and methods

A retrospective study over a year through which data of patients who underwent emergency appendicectomies were collected and analyzed. The absence of inflammatory process and/or other significant pathology in the appendix was considered negative for appendicitis. An utter definition of NA was the absence of inflammatory cells in the appendix. The NA rate (NAR) was calculated using the standard criteria (NAR-SDC) and the strict criteria (NAR-STC). The routine laboratory parameters for diagnosing acute appendicitis on admission were collected. Increased inflammatory markers in the form of leucocytosis of total WBC > 11,000 per mm, elevated CPR > 5 mg/L, and isolated elevated total serum bilirubin > 20 µmol/L, were suggestive of acute appendicitis.

Results

Three hundred and seventy-two patients were included, 179 males and 193 females with a median age were 27 (5-94) years. The median duration of symptoms and waiting time to surgery were two days and one day, respectively. The mean admission WBC, C-reactive protein (CRP) and serum bilirubin levels were 12,600 (3,000-38,000)/mm³, 66.9 (1-323) mg/L and 12.7 (4-38) µmol/L respectively. Laparoscopic appendicectomy was performed in 93.5% of patients with a conversion rate of 4.6%. NAR-SDC was 10.2% and NAR-STC was 25.8%. NAR was significantly higher in females than males (39.4% versus 11.1%; p-value 0.0001). Patients with NA were younger (p-value 0.0001), had lower mean total WBC (p-value 0.014), CRP (p-value 0.0001) and total serum bilirubin (p-value 0.0001) levels on admission.

Conclusion

NA is still a major problem in the management of patients with acute right lower abdominal pain. Our NAR compared favourably with reported rates. Female gender, duration of symptoms more than three days, and lower total WBC were independent predictors of NA.

Accuracy of Mean Platelet Volume (MPV) and Red Cell Distribution Width (RDW) for the Diagnosis of Acute Appendicitis: Evaluation of Possible New Biomarkers

Introduction:

Acute appendicitis is the most common cause of the abdominal pain in surgery. Despite its significant prevalence, the diagnosis is associated with many problems in some cases, which leads to false appendectomy.

Objective:

The aim of this study was to determine the validity of diagnostic tests of mean platelet volume (MPV) and red cell distribution width (RDW), as a new possible tool in the diagnosis of acute appendicitis. Methods: In this study, all patients who referred to the emergency department of Besat Hospital, Hamadan, Iran, in 2015, with abdominal pain and first impression of acute appendicitis, undergone appendectomy, were evaluated. The diagnostic markers of pre-operative and post-operative pathology and the validity of MPV and RDW were determined in diagnosis of acute appendicitis.

Results:

Laboratory and clinical data from 438 patients, presenting the signs and symptoms of acute appendicitis with the mean age of 26.51±13.9 years, were examined (55.6% men). The sensitivity, specificity, positive and negative predictive value of MPV in the diagnosis of acute appendicitis were 59.77, 98.66, 99.5 and 34.26 percent, and for the RDW were 57.79, 56.00, 86.07 and 21.98 percent, respectively. The area under the receiver operating characteristic (ROC) curve for RDW and MPV was 0.61and 0.90, respectively. The mean of MPV in patients with normal pathologic outcome was 9.52±1.60 and in patients with acute appendicitis was 7.51±1.22. There was a significant difference between the mean MPV in both groups (p<0.001). The mean of RDW in patients with normal pathology were 13.42±1.97 and 13.05±1.09, in patients with acute appendicitis. There was a significant difference between the mean RDW of the two groups (p=0.009).

Conclusion:

MPV and RDW indexes have the potential to be used by the surgeons in diagnosis of acute and perforated appendicitis, especially in adults, in order to reduce unnecessary appendectomy, but MPV is more valid in screening acute appendicitis, compared to the RDW.

Derivation and validation of the APPEND score: an acute appendicitis clinical prediction rule

BACKGROUND

Although many clinical prediction rules (CPRs) for appendicitis exist, none have been developed for a New Zealand population presenting with right iliac fossa (RIF) pain. The aim of this study was to derive and validate an appendicitis CPR for our population.

METHOD

This is a retrospective review of all patients from December 2010 to February 2012 of at least 15 years of age presenting to the general surgery service with RIF pain. Patient data were divided into derivation and validation groups. Univariate and multiple regression analyses identified significant predictors of appendicitis which were used to construct a CPR. A retrospective validation study was then performed and the CPR was refined accordingly. Finally, the accuracy of the CPR was tested.

RESULTS

The final components of the new CPR, the APPEND score, were Anorexia, migratory Pain, local Peritonism, Elevated C-reactive protein, Neutrophilia and male gender (Dude). This CPR has an area under the receiver operating characteristic curve of 0.84. The CPR can stratify patients into low, intermediate and high-risk groups which may standardize patient care and reduce the negative appendicectomy rate.

CONCLUSION

A new CPR for predicting appendicitis, in patients presenting with RIF pain, has been derived and validated for use in our population. A prospective study to further evaluate its performance is required.

Predictive factors and outcomes of negative appendectomy

BACKGROUND

The aim of this study was to assess predictive factors for negative appendectomy and to evaluate the outcomes of negative appendectomy.

METHODS

A retrospective chart review of 4,878 patients who underwent appendectomy at our institution from January 2008 to December 2014 was performed.

RESULTS

Younger age (≤15 years), normal white blood cell count, appendix diameter of less than 6 mm on computed tomography (CT), and CT grade less than 3 were found to be independent predictive factors for negative appendectomy. When complications were investigated according to the results of pathologic diagnosis, negative appendectomy had more complications than appendectomy for nonperforated appendicitis, and this was statistically significant.

CONCLUSIONS

When CT findings are equivocal, in deciding to operate for acute appendicitis, additional ultrasonography can be performed. Furthermore, if the patient is younger than 15 years and the white blood cell count is normal, it is recommended to monitor changes in symptoms a little longer rather than operating hastily.

Appendicitis in a deployed military setting: diagnosis, management and impact on the fighting force

BACKGROUND

Acute appendicitis is a principal cause of abdominal pain worldwide and most common in young men who constitute the majority of the deployed fighting force. Diagnostic accuracy is paramount to prevent unnecessary intervention, morbidity and force impact.

METHOD

A consecutive series of appendicectomies, performed over 28 months on deployment in Afghanistan, was evaluated to assess the negative appendicectomy (NA) rate, explore the impact of CT on the rates of NA and assess the impact of appendicectomy on manpower in the deployed workforce.

RESULTS

In Afghanistan, the operative NA rate was 9.6%, whereas the histological NA rate was 20.5%. CT was widely used in Afghanistan (36%) and there was a significant reduction in NA rates if CT was performed preoperatively (6.25% vs 26%, p=0.02).

CONCLUSIONS

Diagnostic imaging will be limited in future conflicts and reliance on clinical judgement will be necessary. Military clinicians may need to accept higher rates of NA, as prolonged observation may not be possible. CT scanning should be used to a greater extent when available. A conservative management strategy for appendicitis with appropriate antibiotics should be considered in the event of delayed transfer to a surgical facility.

Negative appendicectomy rate as a quality metric in the management of appendicitis: impact of computed tomography, Alvarado score and the definition of negative appendicectomy

INTRODUCTION

The negative appendicectomy rate (NAR) is a quality metric in the management of appendicitis. While computed tomography (CT) has been associated with a low NAR, Alvarado scoring produces an acceptable NAR. The definition of negative appendicectomy may affect the NAR. This study examined the impact of CT, Alvarado score and definition on the NAR.

METHODS

The charts of 1,306 emergency appendicectomy patients from 1996 to 2010 were reviewed. Three five-year cohorts were created (Cohort A: 1996-2000, Cohort B: 2001-2005, Cohort C: 2006-2010) and the NAR was calculated for each cohort using two definitions of negative appendicectomy: absence of inflammation (NAR-STD) and absence of intramural neutrophils (NAR-STR). NAR-STD was correlated to the CT rate for Cohorts B and C and also to Alvarado score for Cohort C.

RESULTS

When the definition of negative appendicectomy was changed, the NAR rose from 9.2% to 15.8% (p=0.0097) for Cohort A, from 2.8% to 8.6% (p=0.0180) for Cohort B (CT rate: 80.6%) and from 3.0% to 6.7% (p=0.0255) for Cohort C (CT rate: 92.4%). The introduction of CT lowered NAR-STD from 1996-2000 (9.2%) to 2001-2010 (2.9%) but increasing the CT rate from 2001-2010 had no impact on the NAR. The positive predictive value for Alvarado score (98.60%) and CT (99.03%) were similar.

CONCLUSIONS

The definition of a negative appendicectomy determines the NAR. CT reduces the NAR regardless of definition but routine CT is unnecessary for male patients with positive Alvarado scores. Early/mild appendicitis may resolve without surgery and CT may contribute to unnecessary surgery. Alvarado scoring allows selective use of CT in suspected appendicitis.

Changing incidence of acute appendicitis and nonspecific abdominal pain between 1987 and 2007 in Finland

BACKGROUND

The incidence of acute appendicitis has declined in many countries. The aim of this study was to determine the trends in incidence of acute appendicitis (AA), appendectomies for AA, and nonspecific abdominal pain (NSAP) in Finland between 1987 and 2007.

METHODS

We carried out a national register study. Demographic features were investigated. Diagnoses and procedures were classified according to the World Health Organization International Classification of Diseases. Data were analyzed for each of all five University Hospital districts (UHD) of Finland.

RESULTS

During the observation period of 21 years, 186,558 appendectomies were performed in Finland, of which 137,528 (74%) cases were reported as AA. The incidence of acute appendicitis declined 32%. The diagnostic accuracy improved from 73 to 82% and was higher in men. The accuracy rate among the male patients was stable throughout the two decades; among the female patients it rose from 63 to 75%. The incidence of appendicitis was highest in patients aged 15-24 years. The average incidence of NSAP was 34/10,000/year, and it was higher in older age groups. There was a large geographical disparity in the incidence of NSAP.

CONCLUSION

The incidence of acute appendicitis as well as the incidence of appendectomies is declining in Finland. The incidence of the NSAP has also been declining but we did not find any correlations between the incidences of the acute appendicitis and NSAP. There were clear geographical differences in the incidence of NSAP but not in the incidence of AA.

Decision model for acute appendicitis treatment with decision tree technology--a modification of the Alvarado scoring system

BACKGROUND

How to decide the proper time to do laparotomies for acute appendicitis patients is sometimes very difficult, especially in areas with no imaging diagnostic tools. The Alvarado scoring system (ASS) is a convenient and inexpensive decision making tool; however, its accuracy needs to be improved. The decision tree is the most frequently used data mining technology for diagnostic model building. This study used a decision tree to modify the ASS and to prioritize the variables.

METHODS

We collected 532 patients who underwent appendectomy. Patients who had undergone incidental appendectomy were excluded from the study. The decision tree algorithm was constructed with the data mining workbench Clementine version 8.1. It is a top-down algorithm designed to generate a decision tree model with entropy. The algorithm chooses the best decision node with which to separate different classes from empirical data. The Wilcoxon signed rank test, Student t test and chi(2) test were used for statistical analysis.

RESULTS

Among the 532 patients recruited into the study, 420 had acute appendicitis and 112 had normal appendix. Women with acute appendicitis were older than their male counterparts (p < 0.001). All patients had right lower quadrant tenderness. The new model was constructed with decision tree technology, and the accuracy of the diagnostic rate was better than that of ASS (p < 0.001). The sensitivity and specificity of the new model were 0.945 and 0.805, respectively.

CONCLUSION

The new model is more convenient and accurate than ASS. Right lower quadrant tenderness is an inclusion criterion for acute appendicitis diagnosis. Migrating pain and neutrophil count > 75% were significant factors for acute appendicitis diagnosis if ASS score < 6. Although the criteria of nausea/vomiting and white blood cell count > 10,000/dL were significantly different between acute appendicitis and normal appendix, there was no significant contribution of entropy change below the "neutrophil count > 75%" nodes in the model. So they were erased from the decision tree model. Further studies need to be conducted to investigate why older women are at higher risk for acute appendicitis.

The value of preoperative diagnostic tests in acute appendicitis, retrospective analysis of 196 patients

BACKGROUND

In this study our aim was to evaluate the diagnostic value of preoperative laboratory and radiological studies for appendicitis.

METHODS

The clinical data of 196 patients who have undergone conventional appendectomy between March 2007 and April 2008 were collected retrospectively. Patients were examined for age, sex, white blood cell count, ultrasonography results, histopathological diagnosis and hospital stay.

RESULTS

Negative appendectomy rate was 17.3% (27% for female, 11.5% for male). White blood cell counts were found to be high in 83% for acute appendicitis group and %61 for negative appendectomy group. There were 66 (34%) patients who had negative USG findings for acute appendicitis. Of these patients, histopathological examination revealed acute appendicitis in 46 patients whereas 20 patients had normal appendix. Hospital stays were 2.79 +/- 1.9 and 2.66 +/- 1.7 days for negative and positive appendicectomies respectively.

CONCLUSIONS

Besides the improvement of diagnostic tests for acute appendicitis, we could not sufficiently reduce the negative appendectomy rate.

Has the Pendulum Swung Too Far? The Impact of Missed Abdominal Injuries in the Era of Nonoperative Management

Nonoperative management for traumatic injuries has significantly influenced trauma care during the last decade. We undertook this study to assess the impact of nontherapeutic laparotomies for suspected abdominal injuries compared with delayed laparotomies for questionable abdominal injuries for patients with abdominal trauma. The records of patients admitted to the trauma service between 2002 and 2007 who underwent laparotomies deemed nontherapeutic or delayed were retrospectively reviewed. Demographics, severity of injury, management scheme, and outcome data were analyzed. Sixteen patients underwent delayed laparotomies, whereas 26 patients incurred nontherapeutic laparotomies. Injury severity scores, Glasgow coma scale scores, abdominal abbreviated injury scale score (AIS), and age were similar for both populations. Delayed laparotomies occurred an average of 7 ± 9 days postinjury. Intensive care unit length of stay (26 ± 24 vs 10 ± 6 days), hospital length of stay (40 ± 37 vs 11 ± 10 days), ventilator days (31 ± 29 vs 11 ± 10), and number of abdominal operative procedures (1.9 ± 1.5 vs 1 ± 0) were significantly higher in the delayed laparotomies group versus the nontherapeutic laparotomies group, respectively. Delayed diagnosis of intra-abdominal injuries yielded a significantly increased morbidity and mortality. During the evolving era of technological imaging for traumatic injuries, we must not allow the nonoperative pendulum to swing too far.