Empfohlen
Weitere ähnliche Inhalte
Was ist angesagt?
Was ist angesagt? (20)
Andere mochten auch
Andere mochten auch (16)
Ähnlich wie Necrotizing enterocolitis
Ähnlich wie Necrotizing enterocolitis (20)
Kürzlich hochgeladen
Kürzlich hochgeladen (20)
Necrotizing enterocolitis
- 2. CLINICAL VIGNETTE A 12-day-old male born at 33 weeks becomes lethargic and hypothermic over the course of 24 h. He is not tolerating his formula feeds, has two episodes of bilious emesis, and has three episodes of bloody diarrhea. Physical exam reveals abdominal distention, visible loops of bowel, abdominal wall erythema, and absent bowel sounds.
- 3. EPIDEMIOLOGY • Most frequent & lethal disorder affecting intestines of preterm neonate • Occurs in ~6-7% of very low birth weight infants (< 1500 grams) • May be seen in term infants too, but typically these infants have a preexisting illness (eg congenital heart disease, sepsis) • Incidence decreases with increasing gestational age and birth weight • Overall mortality: 10-50% • Depends on severity of illness & amount of bowel removed • Predicted that NEC will soon surpass neonatal respiratory distress syndrome as principal cause of death in preterm infants
- 4. RISK FACTORS • Prematurity (>95% of cases) • Birthweight ≤ 1,500 grams • Initiation of enteral feeding • Bacterial infection (may be an inciting or a permissive factor) • Intestinal ischemia associated with asphyxia at birth
- 5. CLINICAL FEATURES • MC involved sites: (1) terminal ileum (2) colon • Gross findings: Bowel distension with patchy areas of thinning, pneumatosis, gangrene or frank perforation • Microscopic findings: “Bland infarct” with full-thickness necrosis
- 6. CLINICAL MANIFESTATIONS • Abdominal distension • Bloody stools/rectal bleeding • Pneumatosis intestinalis • Bilious emesis • Absent bowel sounds • Abdominal tenderness/redness • Nonspecific signs (temp instability, apnea/bradycardia, lethargy, hypotension) Note: Actual spectrum of disease ranges from mild cases of feeding intolerance and abdominal distension to severe cases characterized by intestinal necrosis, perforation and septic shock.
- 7. ABDOMINAL RADIOGRAPH FINDINGS Image Source: Brunicardi FC, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE. Figure 39-19 in Schwartz’s Principles of Surgery, 10e, 2014. Abdominal radiograph of infant with necrotizing enterocolitis. Arrows point to area of pneumatosis intestinalis (small gas bubbles in bowel wall) Other Radiographic Findings in NEC • Non-specific bowel dilatation • Thickening of bowel wall • Fixed, dilated loop (unchanged on >1 radiograph) • Portal venous gas • Free intraperitoneal gas (indicates intestinal perforation)
- 8. ABDOMINAL RADIOGRAPH FINDINGS Source: UpToDate. Radiograph of necrotizing enterocolitis in premature infants.
- 9. LAB FINDINGS • Low platelet count • Metabolic acidosis (poor prognostic sign) • Heme-positive stool • Abnormally ↑ or ↓ WBC • Left shift of WBC • Neutropenia • Evidence of DIC
- 10. BELL’S STAGING CRITERIA CLINICAL RADIOGRAPHIC MANAGEMENT SUSPECTED NEC • Mild abd distension • Poor feeding • Emesis • Mild ileus • Medical • Work up for sepsis DEFINITE NEC • Same as Suspected PLUS marked abd distension • Bloody stools • Significant ileus • Pneumatosis intestinalis • Portal venous gas • Medical ADVANCED NEC • Same as Definite PLUS unstable vital signs • Septic Shock • Pneumatosis intestinalis • Pneumoperitoneum (“football sign” indicates severe disruption of intestinal barrier – ie bowel perforation) • Surgical
- 11. DDX • Infectious Enterocolitis (eg Campylobacter, C. difficile, Salmonella, Shigella) • Spontaneous Intestinal Perforation (no pneumatosis intestinalis, occurs within 1st week of life, independent of feeding) • Anal Fissures • Cow’s Milk Protein Allergy (rare in preterm infants, rarely seen < 6 wks old, symptoms resolve after changing feeds to protein hydrolysate or crystalline amino acid formula) • Intestinal obstruction secondary to anatomic/functional condition (eg Hirschsprung disease, ileal atresia, volvulus, meconium ileus)
- 12. MEDICAL MANAGEMENT – SUSPECTED NEC - Make pt NPO - Get baseline KUB - Test all stool for occult blood - CBC, platelets & blood culture - Urine culture & CSF is systemic signs present - Maintenance IVF - Serial abdominal examinations - Consider gastric decompression, abx, stool culture - Observe closely for worsening - If improvement occurs, consider cautious feeding in 3 days
- 13. MEDICAL MANAGEMENT – DEFINITE/ADVANCED NEC • NPO for 7-10 days • IVF (due to “third spacing”, fluid resuscitation to improve bowel perfusion may be needed → eg D5-lactated ringers at 150 ml/kg per 24 hr) • Monitor urine output closely • Gastric decompression • Serial abdominal radiographs to check for perforation (AP & cross table lateral q6-8hr) • Endotracheal intubation/assisted ventilation (as needed) • Circulatory support (volume expanders, dopamine) • Blood culture & antibiotics (amp & gent for 7- 10 days)* • Follow CBC/platelets/PT/PTT/fibrinogen • Measure arterial pH and blood gas tensions • Correct metabolic acidosis • Monitor electrolytes (watch for hyperkalemia!) *Anaerobic coverage usu not needed unless infant if several wks old
- 14. SURGICAL CONSIDERATIONS • Operative intervention is indicated when there is evidence of: • Bowel perforation • Necrotic bowel (fixed loop, metabolic acidosis, DIC, shock) • Progressively worsening clinical condition despite appropriate medical mgmt • For neonates with PDA who develop NEC, begin medical mgmt. Consider urgent operative closure of the PDA, since indomethacin cannot be given to an infant with suspected or definite NEC! • Peritoneal drain may be utilized in extremely ill infants to delay/avoid laparotomy
- 15. COMPLICATIONS • Intestinal Stricture → Bowel obstruction • Short Bowel Syndrome • Cholestasis (if prolonged dependence on TPN)
- 16. REFERENCES • Schanler, RJ. Clinical features and diagnosis of necrotizing enterocolitis in newborns. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. (Accessed on February 27, 2017.) • Hackam DJ, Grikscheit T, Wang K, Upperman JS, Ford HR. Pediatric Surgery. In: Brunicardi F, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE. Eds. Schwartz's Principles Of Surgery, 10e. New York, NY: McGraw-Hill; 2015. Http://Accessmedicine.Mhmedical.Com/Content.Aspx?Bookid=980§io nid=59610881. Accessed February 27, 2017. • UCSF Children’s Hospital. Necrotizing Enterocolitis. Intensive Care Nursery House Staff Manual. 2004. The Regents of the University of California.
Hinweis der Redaktion
- In all infants suspected of having NEC, feedings are discontinued, a nasogastric tube is placed, and broad-spectrum parenteral antibiotics are given. The infant is resuscitated, and inotropes are administered to maintain perfusion as needed. Intubation and mechanical ventilation may be required to maintain oxygenation. TPN is started. Subsequent treatment may be influenced by the particular stage of NEC that is present. Patients with Bell stage I are closely monitored and generally remain NPO (nothing by mouth) and on IV antibiotics for 5 to 7 days, prior to reinitiating enteral nutrition. If the infant fully recovers, feedings may be reinitiated.
- Patients with Bell stage II disease merit close observation. Serial physical examinations are performed looking for the development of diffuse peritonitis, a fixed mass, progressive abdominal wall cellulitis, or systemic sepsis. Serial abdominal radiographs are obtained at regular intervals to look for the presence of pneumoperitoneum or a fixed loop of bowel. If infants fail to improve after several days of treatment or if abdominal radiographs show a fixed intestinal loop, consideration should be given to exploratory laparotomy. Paracentesis may be performed, and if the Gram stain demonstrates multiple organisms and leukocytes, perforation of the bowel should be suspected, and patients should undergo laparotomy.
- In the most severe form of NEC (Bell stage III), patients have definite intestinal perforation or have not responded to nonoperative therapy. Two schools of thought direct further management. One group favors exploratory laparotomy. At laparotomy, frankly gangrenous or perforated bowel is resected, and the intestinal ends are brought out as stomas. When there is massive intestinal involvement, marginally viable bowel is retained, and a “second look” procedure is carried out after the infant stabilizes (24–48 hours). Patients with extensive necrosis at the second look may be managed by placing a proximal diverting stoma, resecting bowel that is definitely not viable, and leaving questionably viable bowel behind, distal to the diverted segment. When the intestine is viable except for a localized perforation without diffuse peritonitis and if the infant’s clinical condition permits, intestinal anastomosis may be performed. In cases where the diseased, perforated segment cannot be safely resected, drainage catheters may be left in the region of the diseased bowel, and the infant is allowed to stabilize.
- Cholestasis – impaired bile flow between liver to duodenum