ACUTE APPENDICITIS
Scientist theorize that appendix is a remnant of an ancient digestive tract .They believe that it might have been used by early man to digest tough leaves and bark.But it can create lot of trouble by causing Acute appendicitis.
The appendix is a worm like extension of the cecum and for this reason,has been called the Vermiform appendix.The average length of the appendix is 8-10 cm ( ranging from 2-20 cm ).The appendix appears during the fifth month of gestation and several lymphoid follicles are scattered in its mucosa.Such follicle increase in number when individuals are aged 8-20 years.
LOCATION
1.Base of appendix:
it is found attached to posteromedial surface of cecum about 2.5 cm below the ileicecal junction.
2.Body and tip of appendix:
a. Retrocecal (74 %)
b. Pelvic (21 %)
c. Paracecal (2 % )
d .Subcecal ( 1.5 % )
e. Periileal (1 %)
f. Postileal (0.5 % )
Vermiform appendix has a complete peritoneal covering, which is attached to lower layer of mesentry of small intestine to form a short mesentry of its own.the mesoappendix,but there is some variations.distal 1/3 of its may be bereft of mesoappendix.
ETIOLOGY
SEX: Males are more commen than female.
SOCIAL STATUS: Upper and middle class
DIET: One relatively rich in meat,& devoid of simple diet rich in cellulose
Familial susceptibility.
OBSTRUCTION OF LUMEN OF APPENDIX:Fecoliyh ,a stricture,a foriegn body,a rond worm.or thread worms.
DISTAL OBSTRUCTION OF COLON: Carcinoma of right colon.
Abuse of purgatives.
BACTERIA: a mixture of E coli,enterococci,non hemolytic streptococci,anaerobic streptococci,Cl welchi,& bacteroids.
PATHOLOGY
NON OBSTRUCTIVE ACUTE APPENDICITIS
Inflammation usually begins in mucosa,& less often in ymph follicles,but on reaching the loose submucosa it progresses rapidly.Organ becomes turgid and dusky red with mucosal hemmorrhages.Vascular supply of distal part of appendix is at risk.because here is the artery is inframural & liable to occlusion by in inflammation or thrombosis,this may lead to gangrene of tip.
Inflammation may progress sufficiently slowly for protective barriers to form ,& the resulting peritonitis is localized .It can terminate in one of the following ways:
Resoluton
Ulceration
Suppuration
Fibrosis
Gangrene
OBSTRUCTIVE ACUTE APPENDICITIS
Products of inflammation becomes pent up,so that it proceeds more rapidly & more certainly to gangrene or perforation.Often within 12-18 hrs,appendix distal to obstruction become gangrenous.Perforation occurs most often at the site of an impacted fecolith before protective adhesions have had time to form-Escaping purulent & gaseous contents are under high pressure ,& early widespread peritonitis is liable to ensue -Subphrenic & pelvic abcesses are a later sequel if patient survives the initial peritonitis.
CLINICAL FEATURES
Age incidence : Increasingly common during childhood & adolescence ,maximum incidence is between 20 & 30 years.
NON-OBSTRUCTIVE ACUTE APPENDICITIS
SYMPTOMS
Abdominal pain which shift : Initially there is constant, vague pain around umblicus,in epigastrium,or it may be generalized.After a few hours pain become intense .& shift to the point where inflammed appendix irritates partial peritoneum ( usually in right iliac fossa ).
Gastric function Upset : Anorexia, nausea, infrequent vomiting & stops as soon as stomach is empty.Usually constipation is present ,but occasionally diarrhea occur.
SIGNS
GENERAL SIGNS : Pyrexia ( 99 - 100 F )
Tachycardia ( 80 - 90 per min )
Tongue ( white & furred )
A special fetor oris
LOCAL SIGNS
Localized tenderness after the pain shifts, either at McBurney's point or elsewhere ( determined by the site of appendix ).
Muscle guarding & rigidity in right iliac fossa .
Rebound tenderness at McBurney's point in right iliac fossa.
Pressure on left iliac fossa may cause pain in right iliac fossa.
Release of pressure on left iliac fossa may cause pain in right iliac fossa.
Last three manoeuvres cause pain because they move the inflamed appendix.
OBSTRUCTIVE ACUTE APPENDICITIS
Sequence of clinical events occurs much more quickly:
Onset is abrupt .& there may be severe generalized abdominal colic from start.However ,the pain shifts in the usuall way.
Vomiting is common
Temperature can be normal
Local signs are as mentioned above.
INVESTIGATIONS
Appendicitis is essentially a clinical diagnosis.
The following may be useful.
- Urine analysis may exclude urinary tract infection.
- Pregnancy test to exclude ectopic pregnancy.
- Abdominal x-ray is of little value.
- A normal white cell count does not exclude appendicitis.
- Ultrasound may be helpful in the assesment of an appendix mass or abcess.
- Ultrasound adds little to the clinical diagnosis of acute appendicitis.
- Scoring system and computer-aided diagnosis may be helpful.
- Meta analysis suggest the following to be useful predictor of appendicitis in patients with abdominal pain.
Raised inflammatory markers '
Clinical signs of peritoneal irritation.
Migration of abdominal pain.
