APPENDICITIS

Dr Phillipo Leo ChalyaM.D. (Dar); M.Med Surg (Mak)

Specialist surgeon - Bugando Medical Centre

FORMAT Definition A historical perspective Epidemiology Aetiology Classification Pathophysiology Clinical presentation Differential Diagnosis Work up Treatment Complications

DEFINITION Appendicitis refers to inflammation of

the vermix appendix

A HISTORICAL PERSPECTIVE

First described by Reginald Fitz in 1886 who also was the first to advocate appendicectomy as the cure

In 1889 Charles McBurney described the clinical findings of acute appendicitis including the point of maximum tenderness in RIF which bears his name

EPIDEMIOLOGY

Incidence: The incidence is higher in developed

countries and in developing countries which are adopting a more refined western type diet

Incidence of appendicitis is lower in cultures with a higher intake of dietary fiber

EPIDEMIOLOGY [cont’d] Mortality/Morbidity:

The overall mortality rate of 0.2-0.8% is attributable to complications of the disease rather than to surgical intervention

Mortality rate rises above 20% in patients older than 70 years, primarily because of diagnostic and therapeutic delay

Perforation rate is higher among patients younger than 18 years and patients older than 50 years, possibly because of delays in diagnosis

Appendiceal perforation is associated with an increase in morbidity and mortality rates

EPIDEMIOLOGY [cont’d] Sex:

The incidence of appendicitis is approximately 1.4 times greater in men than in women

The incidence of primary appendectomy is approximately equal in both sexes

EPIDEMIOLOGY [cont’d] Age:

Appendicitis may occur at all ages, but is most commonly seen in the 2nd and 3rd decades of life

The incidence of appendicitis gradually rises from birth, peaks in the late teen years, and gradually declines in the geriatric years

Although rare, neonatal and even prenatal appendicitis have been reported in literature

The emergency physician must maintain a high index of suspicion in all age groups

AETIOLOGY

Etiological factors for appendicitis include:- Appendiceal luminal obstruction Diet Social status Familial susceptibility

Appendiceal luminal obstruction Luminal causes

Feacolith Lymphoid follicle hyperplasia Worms e.g. ascaris Foreign body

In the wall Stricture Neoplasms

Outside the wall Adhesions kinks

Diet

Low intake of dietary fiber is associated with increased incidence of appendicitis

Dietary fiber is thought to decrease the viscosity of feces, decrease bowel transit time, and discourage formation of fecaliths that predispose individuals to obstructions of the appendiceal lumen

Familial tendency

Appendicitis tends to run in certain families may be due to peculiar position of the organ which predisposes to infection

CLASSIFICATION

Clinical classification Pathological classification

Clinical classification

Acute appendicitis Subacute appendicitis Recurrent appendicitis Chronic appendicitis

Pathological classification

Obstructive appendicitis Non-obstructive appendicitis

PATHOPHYSIOLOGY

Two types:- Obstructive appendictis Non-obstructive appendicitis

Obstructive appendicitis Luminal obstruction and mucus production

result in increased intraluminal pressure Bacteria trapped within the appendiceal

lumen begin to multiply, and the appendix becomes distended

Luminal distention stimulates visceral nerve endings concerned with pain [visceral pain]

This produce dull aching pain felt periumbilically according to nerve supply of the appendix (T10) referred pain

Venous congestion and edema follow next, and by 12 hours after onset, the inflammatory process may become transmural

Obstructive appendicitis[ cont]

Peritoneal irritation then develops If the obstruction is left untreated,

arterial blood flow to the appendix is compromised, and this leads to tissue ischemia and necrosis

This stimulates parietal nerve endings shift of pain to the RIF

Full thickness necrosis of the appendiceal wall leads to perforation with the release of fecal and suppurative contents into the peritoneal cavity

Obstructive appendicitis [cont] Depending on the duration of the

disease process, either a localized walled-off abscess or mass occurs, or if the pathologic process has advanced rapidly, the perforation is free in the peritoneal cavity and generalized peritonitis occurs

The commonest bacterial growth from inflamed appendices include Escherichia coli, Kleblesiella spp., Proteus spp and Bacteroids

Non-obstructive appendicitis This is less dangerous type

Inflammation commences in the mucous membrane or in the lymphoid follicles and gradually spread to the submucosa

As there is no obstruction there is not much distension, but when the serosa is involved localizing peritonitis develops and the patient c/o RIF pain

Such inflammation terminates either by:- Suppuration Gangrene Fibrosis Resolution

Many of the sub-acute appendicitis, recurrent appendicitis and chronic appendicitis develop from this variety

CLINICAL PRESENTATION

History: classic symptoms include:- Periumbilical pain [visceral pain] which

shifts and localize to the RIF [parietal or somatic pain]

Periumbilical pain is colicky in nature in obstructive type and is dull aching and constant in non-obstructive type

RIF pain is sharp intense and well localized to the RIF

Anorexia Nausea & Vomiting

CLINICAL PRESENTATION [cont’d]

Physical examination Pyrexia RIF tenderness Muscle guarding Rebound tenderness Special test to elicit in appendicitis

Pointing sign Rovsing’s sign [RIF pain with palpation of the

LIF ] Psoas sign [RIF tenderness with internal rotation

of the flexed right hip] Obtrurator sign [RLQ pain with hyperextension of

the right hip ]

DIFFERENTIAL DIAGNOSIS

Abdominal disorders Gynecological disorders Retroperitoneal disorders Thoracic disorders Others

Abdominal disorders

Acute cholecytitis Perforated peptic ulcers Entecolitis Intestinal obstruction Carcinoma caecum Crohn’s diseases Amoebic colitis Meckel’s diverticulitis Acute pancreatis

Gynecological disorders

PID Ectopic pregnancy ® Twisted ovarian cyst ® Ruptured ovarian follicles ®

Retroperitoneal disorders

Right ureteric colic Right sided acute pyelonephritis Right sided testicular torsion Retroperitoneal haematoma

Thoracic disorders

Basal pneumonia Pleurisy

Miscellaneous

Henoch-Schoenlein purpura Porphyria Diabetic abdomen

WORK UP

Lab investigations Complete blood cell count

Leucocytosis Neutrophilia greater than 75%

C-reactive protein test Urinalysis

WORK UP [cont’d] Imaging investigations

Abdominal radiography The kidneys-ureters-bladder (KUB) view is

typically used Visualization of an appendicolith in a patient

with symptoms consistent with appendicitis is highly suggestive of appendicitis, but this occurs in fewer than 10% of cases

The consensus in the literature is that plain radiographs are insensitive, nonspecific, and is not cost-effective

WORK UP [cont’d]

Abdominal Ultrasonography An outer diameter of greater than 6 mm,

noncompressibility, lack of peristalsis, or periappendiceal fluid collection characterizes an inflamed appendix

The normal appendix is not visualized It’s noninvasive, short acquisition time,

lack of radiation exposure, and potential for diagnosis of other causes of abdominal pain, particularly in the subset of women of childbearing age

However it is operator dependent

WORK UP [cont’d] Computed tomography

Abdominal CT has become the most important imaging study in the evaluation of patients with atypical presentations of appendicitis

Advantages of CT scanning include Sensitivity and accuracy compared with those of

other imaging techniques Readily available Noninvasive potential to reveal alternative diagnoses

Disadvantages lengthy acquisition time if oral contrast is used patient discomfort if rectal contrast is used Exposure to radiation

It is really required to make diagnosis of acute appendicitis

DIAGNOSTIC SCORING SYSTEM

Various scoring systems have been devised to aid diagnosis of appendicitis

Although many diagnostic scores have been advocated, most are complex and difficult to implement in the clinical situation

The Alvarado score, is a simple scoring system that can be instituted easily

The Classic Alvarado score [1986] is based on three symptoms, three signs and two laboratory findings and has a total score of 10

Classic Alvarado Score [1986]Features Score

Symptoms Migratory RIF pain 1 Anorexia 1 Nausea & vomiting 1Signs Pyrexia 1 Tenderness RIF 1 Rebound tenderness RIF 2Lab investigations Leucocytosis 2 left shift of neutrophil maturation 1

Total 10

Diagnostic Scoring System [cont]

Kalan et al [1994] omitted one lab parameter [left shift of neutrophil maturation] which is not routinely available in many laboratories, and produced a modified score which have only one lab findings

A modified Alvarado score [1994] is based on three symptoms, three signs and one laboratory findings [total score of 9]

MAS is commonly used

Modified Alvarado Score [1994]Features Score

SymptomsMigratory RIF painAnorexiaNausea & vomiting

111

SignsPyrexia Tenderness RIFRebound tenderness RIF

Lab investigationleucocytosis

112

2

Total 9

MASS- interpretation

A score of 1-4:[ discharging group] The diagnosis of acute appendicitis is unlikely

A score of 5-6: [observing group] Probable to have appendicitis but not convincing to have urgent appendicectomy

A score of 7-9: [emergency group] Regarded as probable to have acute appendicitis and needs emergency appendicectomy

TREATMENT

The treatment of appendicitis is appendicectomy

Appendicectomy can be elective, emergency or interval

Two types of appendicectomy:- Conventional open appendicectomy Laparoscopic appendicectomy

Preoperative care

Iv fluid Analgesics Preoperative antibiotics with broad

spectrum antibiotics Check Hb, blood grouping and

crossmatching Shaving Written informed consent Pre-anaesthetic visit

Intraoperative care

Open appendicectomy Incisions

Grid-iron sss Rurtherford Morrison’s Lanz’s [transverse skin crease] SUMI when the diagnosis is not clear Rt lower paramedian Midline incision

Intraoperative care cont’d Appendiceal locations of the tip

Retrocaecal appendix [70%] Pelvic appendix [25%]- the tip hangs in the pelvic brim Subcaecal appendix [2%] Splenic appendix [1%]- either pre- or post-ileal i.e

anterior or posterior to the terminal ileum Paracaecal appendix [1%] Paracolic appendix [1%]-either to the right or left of

ascending colon, the tip in the extraperitoneal tissue Location of the base-is constant, being found at

confluence of 3 taeniae coli of the caecum which fuse to form the outer longitudinal muscle coat of the appendix

Post operative care

Iv fluids Analgesics Antibiotics Monitor- Vital signs Discharge home in 2-3 days

postoperatively

COMPLICATIONS

Complications of acute appendicitis Postoperative complications

i. Complications of acute appendicitis

Appendicular mass Appendicular abscess Recurrent appendicitis Perforation peritonitis

Treatment of complications

Appendicular abscess Appendicular mass Peritonitis Recurrent appendicitis

a.Appendicular mass

Use conservative Ochsner-Sherren regime Iv fluid NGT Analgesics Antibiotics –parenteral Mark the limits of the mass on the

abdominal wall using a skin pencil Monitor- vital sign, size of the mass,

input/output chart Clinical improvement is expected in 24-

48 hours

Appendicular mass [cont]

Criteria for stoping OSR Increased pulse rate Increasing or spreading abdominal

pain Increasing the size of the mass Vomiting or increasing gastric

contents

b.Appendicular Abscess

I & D Antibiotics

c.Recurrent appendicitis

Elective appendicectomy

ii.Postoperative complications Wound infections

Intrabdominal abscess Paralytic ileus Feacal fistula Adhesive intestinal obstruction Portal pyaemia due to septicemia in the

portal venous system Respiratory complications DVT embolism RIH due to damage to iliopogastric /

ilioinguinal nerves Incisional hernia