1、1；.2；.Anatomy 3；.Varied anatomyLength: 510 cm, narrow lumenhaustra of colon4；.EpidemiologyThe most common acute abdomen disease The incidence of appendectomy appears to be declining due to more accurate preoperative diagnosis.Despite newer imaging techniques, acute appendicitis can be very difficult

2、 to diagnose. 5；.Pathophisiology Simple appendicitisSuppurative appendicitis Gangrenous appendicitisPerforated appendicitisPeritonitisAbscess around the appendixMucocele of appendix6；.PathophysiologyAcute appendicitis is thought to begin with obstruction of the lumenObstruction can result from food

3、matter, adhesions, or lymphoid hyperplasiaAppendix is twisted, and Lumen of appendix is narrow, result in obstructionMucosal secretions continue to increase intraluminal pressure7；.Etiology 1. The anatomy characteristics2. The tissue features3. fecality, foreign body obstruction4. Parasites cause th

4、e mucosa damage5. adhesion, pressure cause appendix distortedObstruction high pressure limph obstructed, ischemia mucosa damage bacteria invade（70%80%）8；.Artery The appendix artery has no branches, is easily to be obstacled 9；.EtiologyEventually the pressure exceeds capillary perfusion pressure and

5、venous and lymphatic drainage are obstructed.With vascular compromise, epithelial mucosa breaks down and bacterial invasion by bowel flora occurs.microbes：Ecoli, streptococcus, Pseudomonas, anaerobe10；.EtiologyIncreased pressure also leads to arterial stasis and tissue infarctionEnd result is perfor

6、ation and spillage of infected appendiceal contents into the peritoneum11；.PathophysiologyInitial luminal distention triggers visceral afferent pain fibers, which enter at the 10th thoracic vertebral level.This pain is generally vague and poorly localized.Pain is typically felt in the periumbilical

7、or epigastric area.12；.PathophysiologyAs inflammation continues, the serosa and adjacent structures become inflamedThis triggers somatic pain fibers, innervating the peritoneal structuresTypically causing pain in the RLQ13；.PathophysiologyThe change in stimulation form visceral to somatic pain fiber

8、s explains the classic migration of pain in the periumbilical area to the RLQ seen with acute appendicitis.14；.PathophysiologyExceptions exist in the classic presentation due to anatomic variability of the appendixAppendix can be retrocecal causing the pain to localize to the right flankIn pregnancy

9、, the appendix can be shifted and patients can present with RUQ pain15；.PathophysiologyIn some males, retroileal appendicitis can irritate the ureter and cause testicular pain.Pelvic appendix may irritate the bladder or rectum causing suprapubic pain, pain with urination, or feeling the need to defe

10、cateMultiple anatomic variations explain the difficulty in diagnosing appendicitis16；.Manifestations Primary symptom: abdominal pain to 2/3 of patients have the classical presentationPain beginning in epigastrium or periumbilical area that is vague and hard to localize 17；.Manifestations As the illn

11、ess progresses RLQ localization typically occursRLQ pain was 81 % sensitive and 53% specific for diagnosisMigration of pain from initial periumbilical to RLQ was 64% sensitive and 82% specific18；.Manifestations Associated symptoms: indigestion, discomfort, flatus, need to defecate, anorexia, nausea,

12、 vomitingAnorexia is the most common of associated symptomsVomiting is more variable, occuring in about of patients19；.Physical ExamFindings depend on duration of illness prior to exam.Early on patients may not have localized tendernessWith progression there is tenderness to deep palpation over McBu

13、rneys point20；.Physical ExamRovsings sign: pain in RLQ with palpation to LLQObturator sign: passively flex the R hip and knee and internally rotate the hip. If there is increased pain then the sign is positive21；.Physical examPsoas sign: place patient in L lateral decubitus and extend R leg at the h

14、ip. If there is pain, the sign is positive.Rectal exam: pain can be most pronounced if the patient has pelvic appendix22；.Physical ExamAdditional components that may be helpful in diagnosis: rebound tenderness, voluntary guarding, muscular rigidity, tenderness on rectalFever: another late finding.At

15、 the onset of pain fever is usually not found. Temperatures 39 C are uncommon in first 24 h, but common after rupture23；.DiagnosisAcute appendicitis should be suspected in anyone with epigastric, periumbilical, right flank, or right sided abd pain who has not had an appendectomyWomen of child bearin

16、g age need a pelvic exam and a pregnancy test.Additional studies: CBC, UA, imaging studies24；.DiagnosisThe WBC is of limited value. Sensitivity of an elevated WBC is 70-90%, but specificity is very low.But, +predictive value of high WBC is 92% and predictive value is 50%CRP and ESR have been studied

17、 with mixed results25；.DiagnosisImaging studies: include X-rays, US, CTX rays of abd are abnormal in 24-95%Abnormal findings include: fecalith, appendiceal gas, localized paralytic ileus, blurred right psoas, and free airAbdominal xrays have limited use:for the findings are seen in multiple other pr

18、ocesses26；.DiagnosisLimitations of US: retrocecal appendix may not be visualized, perforations may be missed due to return to normal diameter27；.DiagnosisCT: best choice based on availability and alternative diagnoses.In one study, CT had greater sensitivity, accuracy, -predictive value 28；.Special

19、PopulationsVery young, very old, pregnant, and HIV patients present atypically and often have delayed diagnosisHigh index of suspicion is needed in the these groups to get an accurate diagnosis29；.TreatmentAppendectomy is the standard of carePatients should be given IVF, and preoperative antibiotics Antibiotics are most effective when given preoperatively and they decrease post-op infections and abscess formation30；.TreatmentThere are multiple acceptable antibiotics to use as long there is anaerobic flora, enterococci and gram(-) intestinal flora coverageOne sample monothera