enterocolitis坏死性小肠结肠炎课件

NECROTIZING ENTEROCOLITIS Janice Nicklay Catalan M.D. OBJECTIVES Ability to diagnose and treat the signs and symptoms of NEC Ability to evaluate radiographs for the classic findings of NEC List several long-term complications associated with NEC NECROTIZING ENTEROCOLITIS Epidemiology: most commonly occurring gastrointestinal emergency in preterm infants leading cause of emergency surgery in neonates overall incidence: 1-5% in most NICUs most common in VLBW preterm infants 10% of all cases occur in term infants NECROTIZING ENTEROCOLITIS Epidemiology: 10x more likely to occur in infants who have been fed males = females blacks whites mortality rate: 25-30% 50% of survivors experience long-term sequelae NECROTIZING ENTEROCOLITIS Pathology: most commonly involved areas: terminal ileum and proximal colon GROSS: bowel appears irregularly dilated with hemorrhagic or ischemic areas of frank necrosis focal or diffuse MICROSCOPIC: mucosal edema, hemorrhage and ulceration NECROTIZING ENTEROCOLITIS MICROSCOPIC: minimal inflammation during the acute phase increases during revascularization granulation tissue and fibrosis develop stricture formation microthrombi in mesenteric arterioles and venules NECROTIZING ENTEROCOLITIS Pathophysiology: UNKNOWN CAUSE. PRIMARY INFECTIOUS AGENTS Bacteria, Bacterial toxin, Virus, Fungus CIRCULATORY INSTABILITY Hypoxic-ischemic event Polycythemia MUCOSAL INJURY ENTERAL FEEDINGS Hypertonic formula or medication Malabsorption, gaseous distention H2 gas production, Endotoxin production INFLAMMATORY MEDIATORS Inflammatory cells (macrophage) Platelet activating factor (PAF) Tumor necrosis factor (TNF) Leukotriene C4, Interleukin 1; 6 RISK FACTORS Prematurity: * primary risk factor 90% of cases are premature infants immature gastrointestinal system mucosal barrier poor motility immature immune response impaired circulatory dynamics RISK FACTORS Infectious Agents: usually occurs in clustered epidemics normal intestinal flora E. coli Klebsiella spp. Pseudomonas spp. Clostridium difficile Staph. Epi Viruses RISK FACTORS Inflammatory Mediators: involved in the development of intestinal injury and systemic side effects neutropenia, thrombocytopenia, acidosis, hypotension primary factors Tumor necrosis factor (TNF) Platelet activating factor (PAF) LTC4 Interleukin 1 Vanc/Cefotaxime Clindamycin suspected or proven perforation TREATMENT Surgical Consult suspected or proven NEC indications for surgery: portal venous gas; pneumoperitoneum clinical deterioration despite medical management positive paracentesis fixed intestinal loop on serial x-rays erythema of abdominal wall TREATMENT Labs: q6-8hrs CBC, electrolytes, DIC panel, blood gases X-rays: q6-8hrs AP, left lateral decubitus or cross-table lateral Supportive Therapy fluids, blood products, pressors, mechanical ventilation PROGNOSIS D