|Year : 2017 | Volume
| Issue : 2 | Page : 388-392
Diagnosis of acute appendicitis in low Alvarado score
Samir M Kohla, Ayman A Omar, Tamer A Sultan, Ahmed F Elnakoury
General Surgery Department, Faculty of Medicine, Menoufia University, Menoufia, Egypt
|Date of Submission||21-Apr-2016|
|Date of Acceptance||06-Jun-2016|
|Date of Web Publication||25-Sep-2017|
Ahmed F Elnakoury
Rashid El Behira, 22111
Source of Support: None, Conflict of Interest: None
The aim of this study was to evaluate the efficacy of computed tomography (CT) and ultrasound (US) in the diagnosis of appendicitis in low Alvarado score.
Diagnosis of acute appendicitis is sometimes difficult. Equivocal cases usually require in-patient observation and multiple laboratory and imaging investigations. The combination of the clinical scoring system and advanced imaging has been deeply influential in clinical practice.
Patients and methods
Thirty patients with low Alvarado score below 8 and above 3 were included. US was performed for all patients and CT was performed for patients who had a negative result on US. All specimens of appendectomies were sent for histopathological examination and then their results were compared with the results of US and CT.
The results of this study showed that US had a sensitivity of 72.7%, specificity of 94.7%, and accuracy of 86.7%. The sensitivity, specificity, and accuracy of CT were 100%. Negative appendectomy rate was 15.38%.
The patients with an intermediate Alvarado score (4–7) are the typical group for whom operative decision is difficult. Imaging studies (either US or CT) are useful adjunct to physical and laboratory findings in these patients by decreasing hospital stay and negative appendectomy rate.
Keywords: Alvarado, appendicitis, score
|How to cite this article:|
Kohla SM, Omar AA, Sultan TA, Elnakoury AF. Diagnosis of acute appendicitis in low Alvarado score. Menoufia Med J 2017;30:388-92
| Introduction|| |
Appendicitis is sufficiently common that appendectomy is the most frequently performed urgent operation .
In 1889, McBurney described the clinical findings of acute appendicitis before rupture, including a description of the point of maximal abdominal tenderness that now bears his name. The grid iron incision commonly attributed to McBurney actually was advised by McArther .
The greatest contributor to the treatment of appendicitis is Charles McBurney. In 1889, he published his landmark paper in the New York Medical Journal describing the indications for early laparotomy for the treatment of appendicitis. It is, in this paper, that he described McBurney's point as the point of 'maximum tenderness', when one examines with the fingertips is, in adults, one-half to 2 inches inside the right anterior spinous process of the ilium on a line drawn to the umbilicus .
No age is immune against acute appendicitis but the disease is quite rare during infancy. Its incidence increases slowly to reach its peak in the second and third decades and then declines afterwards .
Clinical decision-making in cases of acute appendicitis is still a matter of debate. The approach to the problem is further highlighted by the desire to reduce the rate of misdiagnosis, to avoid unnecessary surgery on one hand and to reduce the morbidity by operating at an early stage on the other hand. Those with the typical symptoms and signs of acute appendicitis, or suspected cases with definite findings of peritonitis are promptly indicated for surgery .
Immediate appendectomy is the recommended treatment for acute appendicitis because of the presumed risk for progression to rupture .
The overall rate of perforated appendicitis is 25.8% of all cases of acute appendicitis. Children below 5 years of age and patients above 65 years of age have the highest rates of perforation (45 and 51%, respectively) .
There is no accurate way of determining when and if an appendix will rupture before resolution of the inflammatory process .
To avoid complications related to delayed diagnosis or treatment – for example, appendicular rupture, appendicular abscess, or portal pyemia – there is a tendency to overdiagnose the condition, and different studies found a high negative appendicectomy rate (11–30%) ; these rates are even higher in women of childbearing age . However, similar to all operations, postoperative complications can exist, including wound infections, intra-abdominal abscesses, ileus, and, in the longer term, adhesions .
With this in mind, it is worth considering that the mainstay of treatment for other intra-abdominal inflammatory processes, such as diverticulitis, consists initially of conservative management with antibiotics .
In daily clinical practice, the use of a scoring system has been found to be associated with a reduced rate of nonindicated appendicectomies .
In 1986, Alvarado described a scoring system, which has been validated in adult surgical practice . This scoring system includes eight variables: three symptoms (migrating pain from the umbilicus to the right iliac fossa, anorexia, and vomiting), three signs (tenderness, rebound tenderness, and pyrexia), and two laboratory data (leukocytosis and shifting to the left of neutrophil maturation) yielding a total score of 10.
Several works on the comparison of different applications of radiological contrast, comparison of computed tomography (CT) scan and ultrasound (US) images, and evaluation of different diagnostic protocols have been published and discussed .
The combination of the clinical scoring system and advanced imaging has been deeply influential in clinical practice .
| Aim of the Work|| |
The aim of this study was to evaluate the efficacy of US and CT of the abdomen in the diagnosis of acute appendicitis in low Alvarado score by measuring sensitivity, specificity, and accuracy.
| Patients and Methods|| |
A prospective study was conducted during the period from October 2014 to October 2015. This study was carried out on 30 patients with abdominal pain suspecting of acute appendicitis with Alvarado score below 8. Patients were selected from the admitted patients at the Department of General Surgery at Menoufiya University Hospital at Shebin El Kom and Damanhour Medical National Institute.
All patients were subjected to the following:
- Hospital admission
- US examination for all patients
- Patients with positive finding in US suggesting acute appendicitis were prepared for urgent operative intervention
- Patients with positive finding in US suggesting another pathology were referred to subspecialty
- CT scan of the abdomen and pelvis was performed for all patients with negative result in US
- Patients with positive finding in CT suggesting acute appendicitis were prepared for urgent operative intervention
- Patients with positive finding in CT suggesting another pathology were referred to subspecialty
- Patients with negative finding in CT or nonspecific finding were observed clinically and reassessed frequently
- Patients on clinical observation with Alvarado score equal to or more than 8 were prepared for urgent operative intervention
- Patients on clinical observation with Alvarado score equal to or less than 3 after initial symptomatic treatment were discharged and sent home on antibiotic therapy with the instructions to come back to hospital if symptoms recurred or the condition became worse
- Postoperative pathological examination: Histopathological examination of collected specimens of patients who underwent surgical intervention was carried out, and the patients were classified into two groups: the appendicitis and the nonappendicitis group
- All patients in this study were observed for 2 months
- Nonoperated patients with negative radiological finding in US and CT, who on clinical observation had Alvarado score below 4 and on clinical follow-up for 2 months had no recurrence of symptoms were added to the nonappendicitis group. Moreover, among patients with positive radiological finding in US and CT who showed another pathology and the diagnosis was established by a subspecialist were added to the nonappendicitis group
- Finally, all patients were classified into two groups: the appendicitis group and the nonappendicitis group.
The study was approved by the ethical committee of the Department of Surgery of Menoufiya University. The techniques were explained to the patients who accepted it and provided written consent.
Data were fed to the computer using IBM (SPSS Inc., Chicago, Illinois, USA) software package, version 20.0. Qualitative data were described using number and percent.
Comparison between different groups as regards categorical variables was tested using the χ2-test.
| Results|| |
The present study was conducted for 30 patients with complains of lower abdominal pain with clinical suspicion of acute appendicitis with Alvarado score above 3 and below 8. They were admitted in the General Surgery Department of Menoufiya University Hospital at Shebin El Kom and Damanhour Medical National Institute from October 2014 to October 2015.
Distribution of the parameters of Alvarado score as among the studied patients: Tenderness was present in all cases (100%), followed by leukocytosis in 63.3%. The least frequent symptom was the migrating pain, which was present only in 30% of all cases [Table 1].
|Table 1: Distribution of the parameters of Alvarado score among the studied patients|
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Evaluation of patients using Alvarado score
The mean Alvarado score for all patients was 5.80 ± 1.16 and the mean Alvarado score for the appendicitis group was 6.09 ± 1.04, whereas the mean Alvarado score for the nonappendicitis group was 5.63 ± 1.21 [Table 2].
Evaluation according to the management
Of the entire group of 30 patients, 13 (43.33) underwent surgery, whereas 17 (56.66) did not. Of the 13 patients who underwent surgery, 11 patients had appendicitis and two did not have appendicitis [Table 3].
Results of postoperative pathological examination
Histopathological examination of the removed specimens showed that the number of patients with proven acute appendicitis was 11 (84.61%) and the number of patients with normal appendices was two (15.38%). According to the postoperative histopathological examination, seven cases were catarrhal appendicitis, three were suppurative appendicitis, and one case was perforated gangrenous appendicitis.
Estimation of the performance of ultrasound
According to this study, the performance of US can be tested by calculating the overall sensitivity, which was 72.73%, overall specificity (94.73%), positive predictive value, which was 66.67, and negative predictive value, which was 83.3%, and accuracy, which was 83.73% [Table 4] and [Table 5].
|Table 4: Agreement (sensitivity, specificity, and accuracy) for ultrasound to prognose nonappendicitis|
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|Table 5: Agreement (sensitivity, specificity, and accuracy) for computed tomography to prognose nonappendicitis|
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Estimation of the performance of computed tomography
According to this study, the performance of CT can be tested by calculating the overall sensitivity, which was 100%, overall specificity, which was 100%, positive predictive value, which was 100%, negative predictive value, which was 100%, and accuracy, which was 100% [Table 5].
Overall negative appendectomy rate of all studied cases was 15.38%.
| Discussion|| |
In the current study, the sensitivity of US was 72.7%, which is similar to the results of Ozkan et al.  in which it was 71.2%.
Another study conducted by Pickuth et al.  reported a sensitivity of 87%. In contrast to our study, another study conducted by Unlu et al.  showed that the sensitivity of US was 59%.
Specificity of US was 97.7%, which is comparable to the results of Styrud et al.  and Unlu et al.  in their study. Another study conducted by Pickuth et al.  reported a specificity of 74%.
In our study, accuracy of US was 86.7%, which is similar to the results of Pickuth et al. . Another study conducted by Ozkan et al.  and Unlu et al.  reported an accuracy of 65.7 and 71%, respectively. In this study, patients with a lower Alvarado score (4–7) were initially examined by US. A CT examination was performed in patients with clinical suspicion of acute appendicitis but without positive US findings. In these participants, CT showed 100% sensitivity, 100% specificity, and 100% accuracy. These results are similar to the results of Poh et al. , which showed a sensitivity of 93.9%, specificity of 100%, and accuracy of 98.5%. Another study conducted by Ozkan et al.  reported 62.5% specificity and 90% accuracy. In the study by Gamanagatti et al.  the sensitivity of CT was 75%. CT scan was performed only for 18 patients in our study, which explains high result of CT.
When a noninflamed appendix is surgically removed after wrong diagnosis of acute appendicitis, this is called negative appendectomy .
In the current study, the rate of negative appendectomy was 15.7%, which is comparable to the results of Styrud et al. , in which it was 12%.
| Conclusion|| |
Radiological methods such as CT and US, as well as scoring systems have all been used in the diagnosis of acute appendicitis, and each have their benefits and disadvantage.
The patients with an intermediate Alvarado score (4–7) are the typical group for whom operative decision is difficult, especially for adult female patients.
Imaging studies (either US or CT) are useful adjunct to physical and laboratory findings in these patients by decreasing hospital stay and negative appendectomy rate.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]