2020/8/10,.,1,surgery,Acute Appendicitis,2020/8/10,.,2,2020/8/10,.,3,Anatomy,2020/8/10,.,4,Varied anatomy,Length: 510 cm, narrow lumen,haustra of colon,2020/8/10,.,5,Epidemiology,The 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 to diagnose.,2020/8/10,.,6,Pathophisiology,Simple appendicitis Suppurative appendicitis Gangrenous appendicitis Perforated appendicitis Peritonitis Abscess around the appendix Mucocele of appendix,2020/8/10,.,7,Pathophysiology,Acute appendicitis is thought to begin with obstruction of the lumen Obstruction can result from food matter, adhesions, or lymphoid hyperplasia Appendix is twisted, and Lumen of appendix is narrow, result in obstruction Mucosal secretions continue to increase intraluminal pressure,2020/8/10,.,8,Etiology,1. The anatomy characteristics 2. The tissue features 3. fecality, foreign body obstruction 4. Parasites cause the mucosa damage 5. adhesion, pressure cause appendix distorted Obstruction high pressure limph obstructed, ischemia mucosa damage bacteria invade（70%80%）,2020/8/10,.,9,Artery,The appendix artery has no branches, is easily to be obstacled,2020/8/10,.,10,Etiology,Eventually the pressure exceeds capillary perfusion pressure and venous and lymphatic drainage are obstructed. With vascular compromise, epithelial mucosa breaks down and bacterial invasion by bowel flora occurs. microbes：Ecoli, streptococcus, Pseudomonas, anaerobe,2020/8/10,.,11,Etiology,Increased pressure also leads to arterial stasis and tissue infarction End result is perforation and spillage of infected appendiceal contents into the peritoneum,2020/8/10,.,12,Pathophysiology,Initial 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 or epigastric area.,2020/8/10,.,13,Pathophysiology,As inflammation continues, the serosa and adjacent structures become inflamed This triggers somatic pain fibers, innervating the peritoneal structures Typically causing pain in the RLQ,2020/8/10,.,14,Pathophysiology,The change in stimulation form visceral to somatic pain fibers explains the classic migration of pain in the periumbilical area to the RLQ seen with acute appendicitis.,2020/8/10,.,15,Pathophysiology,Exceptions exist in the classic presentation due to anatomic variability of the appendix Appendix can be retrocecal causing the pain to localize to the right flank In pregnancy, the appendix can be shifted and patients can present with RUQ pain,2020/8/10,.,16,Pathophysiology,In 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 defecate Multiple anatomic variations explain the difficulty in diagnosing appendicitis,2020/8/10,.,17,Manifestations,Primary symptom: abdominal pain to 2/3 of patients have the classical presentation Pain beginning in epigastrium or periumbilical area that is vague and hard to localize,2020/8/10,.,18,Manifestations,As the illness progresses RLQ localization typically occurs RLQ pain was 81 % sensitive and 53% specific for diagnosis Migration of pain from initial periumbilical to RLQ was 64% sensitive and 82% specific,2020/8/10,.,19,Manifestations,Associated symptoms: indigestion, discomfort, flatus, need to defecate, anorexia, nausea, vomiting Anorexia is the most common of associated symptoms Vomiting is more variable, occuring in about of patients,2020/8/10,.,20,Physical Exam,Findings depend on duration of illness prior to exam. Early on patients may not have localized tenderness With progression there is tenderness to deep palpation over McBurneys point,2020/8/10,.,21,Physical Exam,Rovsings sign: pain in RLQ with palpation to LLQ Obturator sign: passively flex the R hip and knee and internally rotate the hip. If there is increased pain then the sign is positive,2020/8/10,.,22,Physical exam,Psoas sign: place patient in L lateral decubitus and extend R leg at the hip. If there is pain, the sign is positive. Rectal exam: pain can be most pronounced if the patient has pelvic appendix,2020/8/10,.,23,Physical Exam,Additional components that may be helpful in diagnosis: rebound tenderness, voluntary guarding, muscular rigidity, tenderness on rectal Fever: another late finding. At the onset of pain fever is usually not found. Temperatures 39 C are uncommon in first 24 h, but common after rupture,2020/8/10,.,24,Diagnosis,Acute appendicitis should be suspected in anyone with epigastric, periumbilical, right flank, or right sided abd pain who has not had an appendectomy Women of child bearing age need a pelvic exam and a pregnancy test. Additional studies: CBC, UA, imaging studies,2020/8/10,.,25,Diagnosis,The WBC is of l