Pediatric emergency medicine trisk 0700 0700
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (130.92 KB, 1 trang )
bleeding, a clinician should obtain a type and cross, complete blood count, and
coagulation profile. If needed, fecal occult blood tests (Hemoccult, stool guaiac) can
help to confirm the presence of blood in the stool. Of note, peroxidase-containing
vegetables (cantaloupe, broccoli, cauliflower, turnips) and rare red meats can cause
false-positive fecal occult blood tests. Fecal alpha-1 antitrypsin can also be elevated in
patients with GI blood loss and is more sensitive and specific than a guaiac test.
Bacterial causes (Salmonella, Shigella, Campylobacter, pathogenic E. coli, and Yersinia
enterocolitica ) should be identified with stool cultures. Stool testing may also be
performed if there is concern for Clostridium difficile. In symptomatic infants and
children, the presence of leukocytes in a stool smear (or fecal lactoferrin) may aid in
preliminary diagnosis. Anemia, leukocytosis, thrombocytosis, elevated ESR/CRP,
decreased albumin, and elevated fecal leukocytes support the diagnosis of IBD. Infants
with FPIES can present with a metabolic acidosis, leukocytosis, thrombocytosis,
hypoalbuminemia, and methemoglobinemia. HUS can be identified by microangiopathic
hemolytic anemia, thrombocytopenia, and renal injury.
Diagnostic Approach
Rectal bleeding presents in all pediatric age groups ( Table 33.4 and Fig. 33.3 ). The
causes of lower GI bleeding vary significantly with age, and are often transient and
benign. Occasionally, lower GI bleeding reflects a life-threatening pathologic condition,
and establishment of a specific diagnosis becomes urgent.
The priority in evaluating the patient with lower GI bleeding is to identify lower tract
bleeding associated with intestinal obstruction and with other causes of large volume
bleeding such as a Meckel diverticulum. Intussusception and a late presentation of
midgut volvulus secondary to malrotation are the major types of intestinal obstruction
associated with lower GI hemorrhage. All causes of abdominal obstruction (e.g.,
adhesions, incarcerated hernia, appendicitis) eventually result in bleeding if diagnosis is
delayed and vascular compromise occurs.
Severe lower GI bleeding leading to hemodynamic instability or requiring transfusion
is rare in pediatrics, and gastric lavage is essential in these cases to rule out a possible
upper GI tract source. Meckel diverticulum is the most common cause of severe lower
GI bleeding in all age groups. Following Meckel diverticulum, Crohn disease and
arteriovenous malformation are prominent causes of massive lower GI bleeding in
adolescents.
The urgency and extent of evaluation of patients with lower GI bleeding will depend
on the amount of bleeding, the patient’s age, and associated physical findings. In a
healthy infant with a few streaks of blood in the stool and a normal examination, a
limited evaluation and observation are reasonable. If more significant hematochezia is
found and if a nasogastric aspirate is negative, then significant pathology must be
sought. Flat (AP supine view) and upright (PA erect view [or left lateral decubitus
view]) abdominal radiographs should be performed if an obstructive process (e.g.,
