2. DEFINICIÓN
Proceso patológico el cual ocurre cuando
la propulsión y el paso normal del
contenido intestinal no sucede debido a
múltiples casusas. La obstrucción puede
involucrar solo el intestino delgado,
intestino grueso o a través de alteraciones
sistémicas en el metabolismo, equilibrio
electrolítico y mecanismos
neuroreguladores involucrados en laMichael J. Zinner, Stanley W. Ashley. Maingot´s. Abdominal Operations.
Mc Graw-Hill Medical. Twelfth Edition. 2013.
12. FACTORES DE RIESGO
Cirugías abdominales previas
Hernias
Inflamación intestinal
Historia o alto riesgo de neoplasias
Radiación
Historia de ingesta de cuerpo extraño
18. DIAGNÓSTICO
¿El intestino se encuentra obstruido?
¿Qué tan severa es la obstrucción?
¿En dónde está localizada?
¿Cuál es su causa?
¿Existen datos de estrangulación?
34. BIBLIOGRAFÍA
Michael J. Zinner, Stanley W. Ashley. Maingot´s. Abdominal Operations.
Mc Graw-Hill Medical. Twelfth Edition. 2013.
Jeffrey H. Peters, Jeffrey B. Matthews. Shackelford´s. Surgery of the Alimentary
Tract.
Elsevier Saunders. Seventh Edition. 2013.
Complete obstruction and closed-loop obstruction — The history should determine whether the patient is continuing to pass any gas or stool from the rectum. Cessation of passage of stool or flatus indicates a complete obstruction, which is more likely to be associated with complications (ischemia, necrosis, perforation). However, it is important to remember that passage of flatus or feces can continue for 12 to 24 hours after the onset of symptoms as the more distal bowel decompresses. The absence of air or fluid in the distal small bowel or colon on plain abdominal radiographs or CT scan supports a diagnosis of complete obstruction.
Although plain abdominal films have a reasonable sensitivity for the detection of high-grade small bowel obstruction, they are less useful differentiating small from large bowel obstruction, and differentiating partial obstruction from ileus.
CT criteria for SBO are the presence of dilated small bowel loops (diameter >2.5 cm from outer wall to outer wall) proximally to normal-caliber or collapsed loops distally (Fig 4) (16).
Simple complete SBO secondary to intussusception. Axial CT scan shows distended small bowel loops with intraluminal positive contrast material (arrows) proximal to an intussusception with a targetlike appearance (*). Completely collapsed bowel loops without intraluminal contrast material (arrowhead) are seen beyond the intussusception.
Low-grade partial SBO. Axial CT scan shows distended jejunal loops (arrows) proximal to an intussusception (*) filled with intraluminal positive oral contrast material. There is sufficient flow of contrast material through the intussusception to fill distal small bowel loops (arrowheads).
Small bowel feces sign in a patient with high-grade SBO secondary to postoperative adhesions. Axial CT scan shows gas bubbles mixed with particulate matter (*), a finding that represents the small bowel feces sign. Note the collapsed bowel loops (arrow) distal to the obstruction point.
Small bowel feces sign in a patient with high-grade SBO secondary to postoperative adhesions. Axial CT scan shows gas bubbles mixed with particulate matter (*), a finding that represents the small bowel feces sign. Note the collapsed bowel loops (arrow) distal to the obstruction point.
IV: intravenous. * Parenteral prophylactic antimicrobials can be given as a single IV dose begun within 60 minutes before the procedure. If vancomycin or a fluoroquinolone is used, the infusion should be started within 60 to 120 minutes before the initial incision to have adequate tissue levels at the time of incision and to minimize the possibility of an infusion reaction close to the time of induction of anesthesia. ¶ For prolonged procedures (>3 hours) or those with major blood loss or in patients with extensive burns, additional intraoperative doses should be given at intervals one to two times the half-life of the drug. Δ For patients allergic to penicillins and cephalosporins, clindamycin (900 mg) or vancomycin (15 mg/kg IV; not to exceed 2 g) with either gentamicin (5 mg/kg IV), ciprofloxacin (400 mg IV), levofloxacin (500 mg IV), or aztreonam (2 g IV) is a reasonable alternative. Metronidazole (500 mg IV) plus an aminoglycoside or fluoroquinolone are also acceptable alternative regimens, although metronidazole plus aztreonam should not be used since this regimen does not have aerobic gram-positive activity. ◊ Morbid obesity, gastrointestinal (GI) obstruction, decreased gastric acidity or GI motility, gastric bleeding, malignancy or perforation, or immunosuppression. § Factors that indicate high risk may include: Age >70 years, pregnancy, acute cholecystitis, nonfunctioning gall bladder, obstructive jaundice, common bile duct stones, immunosuppression. ¥ Cefotetan, cefoxitin, and ampicillin-sulbactam are reasonable alternatives. ‡ For a ruptured viscus, therapy is often continued for approximately five days. † Use of ertapenem or other carbapenems not recommended due to concerns of resistance. ** Due to increasing resistance of Escherichia coli to fluoroquinolones and ampicillin-sulbactam, local sensitivity profiles should be reviewed prior to use. ¶¶ In addition to mechanical bowel preparation, the following oral antibiotic regimen is administered. 1 g of neomycin plus 1 g of erythromycin base at 1 PM, 2 PM, and 11 PM, or 2 g of neomycin plus 2 g of metronidazole at 7 PM and 11 PM the day before an 8 AM operation. Issues related to mechanical bowel preparation are discussed further separately.
