Main Issue of the Study
Since the diagnosis of acute appendicitis is normally dependent on patient history and symptoms presented, which have low sensitivity and specificity, the study (Moghimi, Khaledifar, Taheri, Ganji, & Mobesheri, 2015) hypothesizes that the use of imaging techniques such as ultrasound is necessary for accurate and timely diagnosis. In this view, the study asks if there is a correlation between the diagnostic findings of ultrasound and pathology. Goldin et al. (2011) recommend the use of ultrasound in the diagnosis of acute appendicitis because it has the highest specificity and sensitivity of 95.4% and 98.7%, respectively. The study aimed to determine specificity and sensitivity of ultrasound in the diagnosis of acute appendicitis among patients undergoing appendectomy in relation to pathological test (Moghimi et al., 2015). In this view, the findings of the study demonstrated accuracies of physical examination (pathology) and ultrasound in the diagnosis of patients with acute appendicitis.
As the study aimed to determine specificity and sensitivity of ultrasound in the diagnosis of acute appendicitis, it comprises of several critical elements. The first element of the study is the clinical diagnosis of acute appendicitis. According to Goldin et al. (2011), the abdominal pain, which shifts from the umbilical region to the right lower abdominal quadrant, is the main symptom of acute appendicitis. Other symptoms are nausea, anorexia, vomiting, fever, leukocytosis, tenderness, and pain shift. Moghimi et al. (2015) used Alvarado scoring system in scoring symptoms and laboratory outcomes with 9-10 scores for patients with acute appendicitis and scores of 7-9, 5-6, and 0-4 for patients with high, medium, and low odds of having acute appendicitis, respectively. Hence, the Alvarado scoring system offers accurate clinical scores for the diagnosis of acute appendicitis.
The second element of the study is the diagnosis of acute appendicitis using ultrasound. The patients who underwent clinical diagnosis then went through ultrasound to confirm the diagnostic outcomes of the Alvarado scoring system. The third element of the study is the pathological examination of biopsies obtained during the appendectomy. The purpose of the pathological examination is to provide accurate diagnosis for the confirmation of acute appendicitis (Moghimi et al., 2015). Statistical analysis was then used to compare the diagnostic outcomes of clinical assessment, ultrasound, and pathological examination.
Validity of the Results
The results of the study are valid because the research design employed and the research instruments used have a scientific basis. Zumbo and Chan (2014) argue that the methodology of a study determines the validity of the findings. As 500 patients with acute appendicitis participated in the study (Moghimi et al. 2015), the findings have high external validity for they represent a significant proportion of patients with appendicitis in a given region. Piantadosi (2013) recommends the use of large sample sizes and extensive clinical diagnoses to increase the external validity of the findings.
Moreover, given that the study employed a retrospective quantitative study, the results have high internal validity. A quantitative study offers more valid results than a qualitative study for it is not prone to researchers’ biases (Hesse-Biber, 2010). Since the study employed the clinical scoring system, the clinical outcomes are valid. According to Ohle, O’Reilly, O’Brien, Fahey, and Dimitrov (2011), the Alvarado scoring system has a specificity of 81% and a sensitivity of 99% in the diagnosis of acute appendicitis. In their study, Goldin et al. (2011) found out that ultrasound has a specificity of 95.4% and a sensitivity of 98.7%. Therefore, the use of large sample size, qualitative study, the scoring system, and ultrasound points out that the findings are valid as confirmed by pathological findings.
Clinical diagnosis of the 500 patients indicated that 77% were likely to have or develop acute appendicitis while the remaining 23% were unlikely to develop appendicitis (Moghimi et al. 2015). The classification of the patients, according to their likelihood to develop acute appendicitis, was based on the Lvardv score of 5 and above. Ultrasound results indicated that 75.7% of the patients had a positive test for acute appendicitis while the remaining 24.3% had a negative test for acute appendicitis. Confirmation of the tests using pathological examination showed that 81.5% and 18.5% of the patients had positive and negative tests for acute appendicitis. Comparative analysis of the ultrasound and pathological results indicated that ultrasound has a specificity of 27.8% and a sensitivity of 76.9% with a false positive of 16.6% and a false negative of 17.8% (Moghimi et al. 2015). Furthermore, the findings show that ultrasound has negative and positive predictive values of 89.2% and 42.6%, correspondingly. Thus, the findings suggest that ultrasound is an invaluable diagnostic test of acute appendicitis in healthcare settings.
Application of the Results
As a registered nurse, I can apply the results of the study in the diagnosis of acute appendicitis among patients. From the findings, it is apparent that there is a considerable correlation of clinical diagnosis using the Alvarado scoring system and ultrasound results with the pathological results. Merhi, Khalil, and Daoud (2014) assert that the Alvarado scoring system and the clinical judgment are central to the diagnosis of acute appendicitis. The findings are also relevant to nursing for they indicate that ultrasound has acceptable levels of sensitivity and specificity in the diagnosis of acute appendicitis. Some studies have established that the accuracy of ultrasound is subject to the expertise and experience of the radiology coupled with the knowledge of gastrointestinal tract (Gracey & McClure, 2007; Mostbeck et al., 2016). Thus, in nursing practice, it is imperative to consider expertise, experience, and specialization of radiologists in the diagnosis of acute appendicitis due to the subjectivity of the diagnosis.
Funding and Objective
The article indicated that researchers received no funding to undertake the study. However, Shahrekord University of Medical Sciences through the Research Department provided financial support to the researchers (Moghimi et al. 2015). The objective of the study was achieved for the researchers managed to establish the accuracy of ultrasound in the diagnosis of acute appendicitis.
Strengths and Limitations
One of the strengths of the study is that it used reliable instruments in data collection. Sullivan (2012) points out that a reliable instrument measures a given attribute in a consistent manner. Another strength is that the study used a large sample of participants and thus, enhancing external validity of the findings. The use of the quantitative approach is strength because it boosts internal validity of the findings. The limitations of the study are that retrospective study is prone to miscalculation and has lower level of evidence than that of a prospective study.
The findings have indicated that ultrasound has considerable sensitivity and specificity in the diagnosis of acute appendicitis. These findings suggest the implementation of ultrasound as a diagnostic test for acute appendicitis because it is not only accurate but also noninvasive and safe diagnostic method. As a registered nurse, I recommend the use of ultrasound in the diagnosis of people who presents symptoms of appendicitis before undertaking appendectomy. Due to high sensitivity, the use of ultrasound in the diagnosis of appendicitis will reduce surgery costs associated with a false positive appendectomy. Comparative studies have demonstrated that sensitivity and specificity of ultrasound are dependent on the expertise, experience, and specialization of radiologists. In this view, an effective implementation of ultrasound as a diagnostic tool requires training of radiologists so that they can gain advanced skills essential for accurate diagnosis of appendicitis.
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