Acute appendicitis has a broad variety of symptoms and indications, making diagnosis difficult. With the use of two case studies, this article illustrates the medical management of acute appendicitis.

Case 1

Acute appendicitis typical presentation

A 24-year-old woman with no past medical history came to the emergency department with abdominal pain, nausea, and vomiting. The pain started 6 hours before in the periumbilical region and is now localised to the right lower quadrant. She denied h/o hematemesis, diarrhoea, hematochezia, and melena.

Diagnosis

Physical examination revealed a low-grade fever of 101 °F and tenderness on palpation of the right lower quadrant.

Her Laboratory parameters were as follows:

• Hb 13.2 mg/dl
• Hematocrit 40.1%
• WBC 13700 cells/mm3
• Platelet count 350000 cells/mm3
• WBC differential Segmented neutrophils 70 %
• Band neutrophils 8%
• Lymphocytes 18%
• Monocytes 3
• Eosinophils 1%
• CRP 30 mg/L
• β-hCG Negative

Abdominal ultrasonography confirmed a diagnosis of appendicitis by the presence of free fluid within the RIF and within the 6mm appendix which was incompressible.

These findings were in keeping with appendicitis.

Management

1. She started on conservative management while in A&E.
2. Following this, she was transferred to OT for surgery.
3. A laparoscopic appendicectomy was performed under general anaesthesia. Post-procedure, the patient was stable.

Case 2

Acute appendicitis with atypical presentation

A 30-year-old man presented to our ED with the chief complaint of non-bloody diarrhoea, nausea, and a loss of appetite for the last 8 hours. He also had abdominal pain more prominent in the lower quadrants. The pain was colicky, 6/10 in intensity and non-radiating. There was no history of dysuria, urinary frequency, or hematuria. His medical history was significant for episodes of gastroenteritis for the past two years.

Diagnosis

1. On arrival, the patient had a blood pressure of 110/70 mmHg. The pulse rate of 96 beats/min, and the oral temperature of 37.6°C.
2. On physical examination, he had generalised abdominal tenderness that was strongest in the lower abdomen. Started on conservative management.
3. Initial laboratory test results showed a white blood cell count of 18.0 cells/mm3 with 80% segmented neutrophils and CRP 38 mg/L.
4. He had normal liver function tests.
5. Urine and stool analysis did not reveal any abnormalities.
6. Due to his presentation, the USG abdomen was performed, which did not visualise the appendix.
7. Therefore, a CECT abdomen was done which showed severe inflammation of the pericecal mesenteric fat and a blind loop thickened appendix, which was diagnosed as retro cecal acute appendicitis.

Management

Surgery on the same day confirmed retro cecal appendicitis. Laparoscopic appendectomy was done on the same day and was discharged home after a week.

Discussion

Acute appendicitis involves acute inflammation of the vermiform appendix located at the tip of the cecum in the right lower quadrant.

Pathogenesis 

1. The most common cause is fecalith.
2. Another leading factor, especially in children, is lymphatic hyperplasia.
3. Other causes include calculi, seeds, and parasites such as Enterobius vermicularis (pinworm).
4. Rare tumours, benign (mucinous tumours) or malignant (adenocarcinoma, neuroendocrine tumours).

Dietary risk factor 

• A diet low in fibre
• Increased sugar intake
• Decreased water consumption

Environmental factors

• Exposure to polluted air, allergens, cigarette smoke
• Gastrointestinal infections

The clinical presentation of acute appendicitis depends on

• Patient's age
• Duration of onset of symptoms
• Anatomical variation of appendiceal position

Commonly used diagnostic signs for appendicitis

McBurney's, Rovsing's, Psoas, and Obturators.

Three major types of appendicitis based on anatomy are: 

• Rectocecal/Retrocolic (75%)
• Sub-caecal/ Pelvic
• Pre-ileal and Post-Ileal types

Atypical signs and symptoms of appendicitis

1. These may include left-sided abdominal pain, which localises to the left upper quadrant. While a left-side appendix is relatively rare, occurring in approximately 0.02% of the adult population, it is more likely to occur in individuals with gut malrotation or situs inversus.
2. Appendicitis is also associated with diarrhoea as an atypical symptom in advanced appendicitis, especially in patients with inter enteric abscesses.
3. Children may involve pain and tenderness along the entire right flank, extending from the right upper quadrant to the right iliac fossa. This could result from arrested caecal descent of the appendix, where the caecum is in the subhepatic position.
4. Adult males may present with atypical appendicitis symptoms, such as severe right hemiscrotal pain that later becomes mild diffuse abdominal pain.
5. Adult females may present with genitourinary complaints such as tenderness in the femoral region with a mass and diarrhoea.
6. Elderly, appendicitis can present atypically as a strangulated inguinal hernia with non-specific symptoms.
7. Pregnant patients are more likely to present atypical complaints such as gastroesophageal reflux, malaise, pelvic pain, epigastric discomfort, indigestion, flatulence, dysuria, and altered bowel habits.

Diagnosis of acute appendicitis

Biochemical parameters in the diagnosis

• Total leucocyte count (TLC)
• C reactive protein (CRP)

Newer markers are as follows:

• Absolute neutrophil count
• Calprotectin (CP)
• Serum amyloid A (SAA)
• Myeloid-related protein 8/14 (MRP 8/14)
• Hyperbilirubinemia and hyponatremia in complicated appendicitis
• Delta neutrophil index has been studied as a reliable biomarker in the elderly

Role of scoring systems in the Diagnosis of acute appendicitis

Alvarado scoring system was initially used in diagnosing AA, and it has high sensitivity but low specificity.

Other scoring systems

• Appendicitis Inflammatory Response Score (AIRS)
• Adult Appendicitis Score (AAS)
• RIPASA (Raja Isteri Pengiran Anak Saleha Appendicitis) score
• Pediatric Appendicitis Score (PAS) and Pediatric Appendicitis Laboratory Score (PALabS) for children

Role of Imaging in the Diagnosis

1. USG - First line

2. CECT - Gold standard

3. MRI - Pregnant Patients

4. Diagnostic Laparoscopy

1. Diagnostic laparoscopy is recommended in patients with an atypical presentation, equivocal imaging findings, and persistent or worsening symptoms.
2. Serve as a diagnostic and therapeutic tool.
3. Effectively diagnose and treat AA and reduce the risk of complications.

Medical management

1. Non-operative management

1. Patient observation.
2. Oral intake restriction.
3. Intravenous and oral antibiotics are recommended for cases of uncomplicated appendicitis.
4. There is currently no established antibiotic regimen for the non-operative management of acute appendicitis.
5. The best antibiotic combination for non-operative therapy was suggested to be Carbapenems based on a recent meta-analysis.

2. Operative management of appendicitis

1. For all cases of acute appendicitis, including difficult cases, in all age categories, guidelines currently advocate laparoscopic appendectomy.
2. Recent research suggests that single-incision laparoscopic surgery (SILA) is preferable to conventional multi-incision laparoscopic appendectomy (CLA).
3. Endoscopic Retrograde Appendicitis Therapy (ERAT)

• Success rates range from 92.1% to 99.4%
• Low complication rates
• Better pain outcomes
• Shorter hospitalisation

4. Natural Orifice Transluminal Endoscopic Surgery (NOTES)- Controversial and lacks recommendations.

Disclaimer- The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of M3 India.

About the author of this article: Dr Jimmy Patel is a practising gastroenterologist in Chennai.