Acute Appendicitis: A Narrative Review Article

Amit Kumar Gupta and Pankaj K Gharde^*

^*Correspondence: Pankaj K Gharde, Department of Surgery, Jawaharlal Nehru Medical College, Datta Meghe institute of Medical Sciences (Deemed to be University), Sawangi (Meghe), Wardha, Maharashtra, India, Email:

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Introduction

Acutely inflamed appendicitis presents as the important and common abdominal emergency condition in clinical practice worldwide because overall incidence is estimated to be 5-10% with a male: female ratio 3:2 that presents most commonly in fourth decade of life, requiring sometimes immediate surgery. It is rare in infants, common in children (male=female). Maximum incidence: teenage (male>female). It is also common in adults. The diagnosis and the determination to intervene or look after or further examination of a patient is sometimes unclear and often challenging [1-3]. A delay in diagnosis can leads to dangerous issues such as rupture of appendix, infectious condition of appendix, abdominal adhesions, abscess formation [2]. A clinical classification is used for the plan of management of simple i.e., nonrupture and complex i.e., gangrenous or perforated inflammation. Some simple cases of appendicitis is selfhealing and respond well to antibiotics, whereas some complex cases perforate before the patient reaches to doctor and presents as complicated cases [3]. A number of new strategies as well as diagnostic procedures like patient interview pathways, ALVARADO systems, USG, computed tomography SCAN, and diagnostic abdominal laparoscopy have been developed and refined [4]. This review article aim to analyze and report the evidence in the Approaches used for diagnosing acute appendicitis.

Methods

Data sources

To find papers that evaluated the Diagnosis of Appendicitis, we conducted a comprehensive literature search using PUBMED, EMBASE, LILACS, and the Cochrane Database. These articles were identified using the terms. Appendicitis diagnosis; ALVARADO clinical scoring system; imaging in appendicitis; CT scan in appendicitis patient; US in patients with acutely inflamed appendix; blood serum markers in appendicitis; blood serum biochemical markers(novel) in appendicitis were some of the key search phrases employed. To find the high quantity of articles, the keywords were combined in various ways. Relevant article references were also checked and added if they were relevant.

Alvarado scoring system

ALVARADO clinical scoring system which was developed in Philadelphia used to know the risk in patients presents as acute abdominal pain of appendicitis. It is based on retrospective study data of about 310 patients in which acute appendicitis is suspected and presents as abdominal pain [1,2]. According to original Alvarado scoring system it has sensitivity of range 75-85% and specificity of range 70-80% [5].

Table 1 shows Alvarado scoring interpretation used for the diagnostic approach in patients of appendicitis.

Table 1: Alvarado scoring interpretation used for the diagnostic approach in patients of appendicitis.

A score of <5 is possible or not sure or unlikely.

A score of 5 or 6 categorized as possible or probable or compatible appendicitis.

Score 7 or8 is considered likely

Score of 9or10 is highly suggestive of appendicitis.

The Alvarado scoring system can be used in assessment of suspected appendicitis patients as it help to predicts appendicitis. However, the clinical scoring system cannot efficiently predict appendicitis without further clinical assessment and therefore should not be used alone for the confirmation of diagnosis and in plan of management [2].

There are several additional scoring systems:

The Kalama modified Alvarado scoring system (1994), which eliminates the movement to the left.

Tzanakis grading system: lower abdominal quadrant tenderness: 4, rebound palpation tenderness: 3, total count > more than twelve thousand per cm-2, and using features: 6.

The 15-parameter RIPASA rating system was developed in 2010.

There are eight parameters in the Anderson scoring system.

The asymptomatic clinical manifestations in teenagers under the age of five years, along with the difficulty in conversation with them, insufficient clinical examination, uncooperative, and mixing of complaints with other common teenager illnesses, all contribute to the delayed confirmation of appendicitis, which leads misdiagnosis. As a result, they are more prone to experience problems [6]. In pediatric age group Pediatric appendicitis risk scores is used. The PAS is a ten-point scale made up of eight components, including symptoms, physical examination results, and WBC statistics. When adopting a score threshold of 6 points or above, Samuel found a sensitivity >98 percent and >92 percent specificity for the PAS in detecting appendicitis in their initial sample of 1170 individuals. Other scientists, on the other hand, have found the PAS to be less trustworthy [7].

Bio serum markers

Bio serum markers are being used to enrich a patient's presenting chief complaints and clinical examination in scenarios where a clinical diagnosis is complicated to draw. Because inflammatory indicators like white cell count, C-reactive protein (CRP), along with other emerging assays like procalcitonin are non-specific, they cannot predict appendicitis alone [8].

The sensitivity and specificity of a white blood cell (WBC) cut-off possible total than 10,000-12,000 cell/ mm3 approximately 70-80 percent and 30 percent and 80 percent, respectively. It serves a general role in inflammatory responses and cannot be relied on solely [2]. C-reactive protein (CRP) is a phase reactant whose importance stems from both for acute increasing features and its diagnostic value as a bio serum marker for dangerous/end stage appendicitis. CRP levels rise 8-12 hours after inflammation begins, peaking 48 hours afterwards (later than WBC) [9,10]. A sensitivity of 60 percent to 90 percent and a specificity of 55 percent to 75 percent are achieved with a value of >10 mg/L. It has modest diagnostic value in the preliminary phase of uncomplicated appendicitis but is a good predictor of appendiceal perforation [1,10].

Granulocyte Count and Proportion of Polymorph nuclear (PMN) cells

The sensitivity and specificity along with ratios, and accuracies of granulocyte count and fraction of PMN in the diagnosis of acute appendicitis were evaluated in 10 papers including one meta-analysis.

And in acute appendicitis, a somewhat raised PMN of more than 7-8 x109 cells/L has a sensitivity of 70-90 percent and a specificity of 45-80 percent [11-15].

When the White cell count, C-RP, and PMN ratios are all within desired limits, acute appendicitis can be ruled out, according to the data, and a rise in any of the biomarkers cannot be trusted upon to predict appendicitis. Although a combining all the known markers increases the chances of appendicitis diagnosis, clinical linkage is still indicated because they all are non-significant markers of inflammation [2].

Temperature

In acute appendicitis, a rise in temperature has practically little diagnostic value [11,12,16]. In a study of around 495 individuals with a fever higher than 38°C, sensitivity 70 percent and a specificity of 65 percent was reported [17]. Another meta-analysis found a probability ratio of 1.64 in 570 individuals with probable appendicitis and a history of fever [11]. Despite the fact that initial starting temperature does not give much value in diagnosis, it is nevertheless used to observe someone with suspected appendicitis [1]. Pain, vomiting, and an increase in fever are all part of the MURPHY'S trifecta.

Novel blood serum markers in appendicitis Interleukin 6 (IL-6)

This cytokine is well-known for its involvement in the stimulation of the acute inflammatory response. Increased IL-6 elevates during the premature stages of appendicitis were reported to have a sensitivity of 80 to 85 percent, a specificity of 65 to 70 %, and an AUC 0.78 was found in a trial. Although there appears to be a link between IL-6 concentration and the severity of inflammation, it's been proved to be disdainful to other blood indicators in the diagnosis [2,12,18].

Serum Amyloid A (SAA)

This is a non-particular immune marker and has a role in diagnosing appendicitis in early stages in children’s [2]. In this investigation, sensitivity 80-85 percent, a specificities of 82-85 percent, and an AUC of 0.96 were demonstrated [19]. SAA may indeed be helpful in the early stages of diagnosis, but further data is required to validate this [2].

Leukocyte gene expression (Riboleukograms)

These proteins have shown merit as a very sensitive appendicitis diagnostic (sensitivity 80-95 percent, specificity 60-70 percent), but key limitations include cost and technical feasibility in real time [20].

Granulocyte colony-stimulating factor

It operates on the bone marrow to initiate the generation and release of granulocytes into the blood circulation and corresponds with the intensity of the inflammatory response. It is effective in exact diagnosis prediction of appendicitis in teenagers, with a sensitivities of 85-95%, a specificities of 45-55%, and an AUC of >2 [2,21].

Urine Leucine-rich α-2-glycoprotein (LRG)

LRG levels have been shown to be heightened in the urine of clients with clinical presentation of acutely inflamed appendicitis in the absence of macroscopic abnormalities, and it has been shown to be a potential diagnostic tool in children [22]. The focus of current research is to assess the sensitivity and specificity in diagnosis. A research is underway to develop a consistent and feasible laboratory approach for correctly measuring LRG in the clinical setting [2]. Alone with elevated level of inflammatory markers, signs of appendicitis mentioned below are positive and help in diagnosis.

The signs of appendicitis based on location

Retrocecal appendicitis

Psoas sign present and patient can keep his right leg in flexion.

Pelvic appendicitis

Irritate rectum: Pelvic diarrhoea and tenesmus.

Irritate bladder: Increased frequency of urine urge.

Pain in digital rectal examination.

Post-ileal appendicitis

Hardly any signs elicited and slight pain on deep pressure.

Differential diagnosis of acute appendicitis

Infants and children

Yersinia: mesenteric adenitis, fever is common.

Intussusception.

Bowel obstruction.

ureteric colic.

Meckel’s diverticulitis.

Adult

Ureteric colic/Gastroenteritis/Bowel obstruction/ Torsion.

Adult females

Mittelschmerz: Mid-cycle ovulatory pain

Endometriosis

Pelvic inflammatory disease

Ectopic pregnancy.

Elderly

Diverticulitis/ureteric colic/obstruction.

Investigation of choice

In adults: CECT

In children: USG→Elongated tubular structure, noncompressible, blind ending, probe tenderness, free fluid, Diameter >6 mm.

Radiological imaging

Preoperative imaging plays important role in diagnosis. Three modalities are available for radiological diagnosis:

Ultrasonography (US).

Computed tomography (CT-scan).

Magnetic resonance imaging (MRI).

CT is aureate standard for diagnosing appendicitis and has a unique place among imaging methods as it deliver report within minutes with reported sensitivity and specificity between 83%-98%. Compared to pre-CT era negative appendectomy rate is decreased to less than 10% from 21.5% [2,23].

The best CT strategy for appendicitis diagnosis is a contentious subject of debate. The effective recommended dose: low or normal dose, as well as the possibility of enteric and IV delivery of an iodinealong with contrast agent, are all variables. In the event of suspected appendicitis, unenhanced and contrastenhanced effective CT doses are important in both methods. As a result, it must be kept as less as feasible while maintaining consistent diagnostic quality, and the ALARA principle should be followed [23].

Coursey, et al. looked examined the impact of preoperative CT on the rate of negative appendectomy in patients with suspected appendicitis in a retrospective analysis. The frequency of preoperative CT exams went from 18.5 percent to 93.2 percent over a 10-year period, resulting in a decrease in the percentage of negative appendectomies from 16.7% to 8.7%, according to the authors [24]. Apart from that, ultrasound scanning (US) is the widely utilized imaging technique, with sensitivity and specificity ranging from 70% to 95% in confirming the diagnosis of appendicitis [25]. The most prevalent cause of an acute abdomen during pregnancy is acute appendicitis. While US provide acceptable diagnostic findings in the first and second trimesters, due to the altered anatomy, examination circumstances in the third trimester are severely restricted. The appendix is shifted from the lower right quadrant to the upper right quadrant during pregnancy due to the uterus's growth, as well as by the ventral abdominal wall. There is no longer any annoyance of peritoneum resulting in localized discomfort [25].

Both techniques have their own limitations, common problems for US has clinician variableness, and the problem in locating the appendix due to BMI, anatomical variation and overlaying bowel gases. For CT being highly costly, reporting by the examiner along with deliberation for high exposure to radiation and have contrast related issues [26]. To avoid the radiation exposure and increase the sensitivity of diagnosis of CT in ambiguous cases, specific US criteria and repeated US scans have been adopted and this shown to improve US’s diagnostic accuracy of 100% [27]. Studies on different aspects of appendicitis were reported [28-32].

Patients with unique radiation protection needs, such as young people, particularly women of reproductive age, women whose pregnancy cannot be close out in an emergency scenario, and the pregnant women, should have an MRI. In the case of doubt of appendicitis, an MRI of the abdomen doesn't need any targeted evacuation or other patient preparation. Contraindications aside, intravenous injection of butyl scopolamine bromide decreases peristalsis, resulting in enhanced picture quality [25]. Early detection of acute appendicitis during pregnancy is critical because it reduces complications that might jeopardize the mother's and unborn child's lives. Traditional MRI (T1/T2weighted sequences) has a sensitivity and specificity of 90 percent to 100 percent for diagnosis [23]. Appendicitis is constituted by an inflamed appendix with a diameter >7mm, swelled compaction of the adjacent mesenterial adipose tissue, restricted dispersal in the thicker appendiceal wall, and the development of an carbuncle in the right lower abdomen following appendix rupture.

Radiological diagnosis is crucial and necessitates a radiologist with a high degree of skill. A compromise must be struck between lowering expenses, minimizing radiation exposure, obtaining a high rate of negative appendectomy, and providing a quick and accurate diagnosis; for this, an optimum method integrating US, CT, and MRI is required.

Conclusion

The goal of this article is to outline the information for several currently accessible methods to appendicitis diagnosis and work - up. For this reason, we discussed clinical scoring systems, laboratory testing results, new biomarkers, and radiological imaging in our research.

In conclusion, elevated Alvarado scores, in combination with laboratory indicators (WBC, CRP, PMN), add to the speculation of appendicitis, but not a bit of them alone can predict the diagnosis, and surgical action should not be based just on one of them. When utilized together, though, they show greater promise. CT has always been the best radiological modality for detecting appendicitis, although it comes with hazards owing to radiation exposure, especially when compared to ultrasonography, which can assist reduce the need for CT in some situations. In elders, an Alvarado score of eight or above shows promise in ruling out appendicitis. Children or adults with acute appendicitis should be brought to the hospital right away for observation and/ or an emergency appendectomy. Atypically presenting, necessitate surgical consultation. Differentiating atypical acute appendicitis from other diseases may need inpatient surveillance by a surgeon.

Patients with a very low risk, as determined by the clinical Alvorado scoring system or PAS scoring systems, may had released from the hospital room with instructions to return in 8 to 12 hours for another examination. The specific imaging route sequence and threshold have yet to be defined. In the interim, we recommend that low-radiation CT be widely considered, as it has been shown to be just as accurate as standard CT scanning or repeated US.

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