Small Bowel Obstruction
Jonathan F Swanson, MD, Akinniyi E Fadipe, MCS (ECSA), and Samuel L Burleson, MD
Department of Emergency Medicine, University of Alabama at Birmingham Hospital, Birmingham, AL, USA & Department of Surgery, Tenwek Hospital, Bomet, Kenya
A 37-year old male on intensive phase tuberculosis (TB) treatment presents with 3-day history of generalized moderate abdominal pain and loss of appetite. Reported passage of small amounts of stool. No history of fever.
|Blood pressure||Pulse||Respiratory Rate||Pulse Oximetry||Temperature|
General: The patient is ill-appearing, in distress from pain, and moderately dehydrated.
Neurologic: No gross abnormality: GCS 15, neck is supple.
Abdomen: Distended, reduced movement with respiration, general tenderness with guarding and rebound. No obvious external hernia. Bowel sounds reduced. Digital rectal exam revealed minimal normal stool in the rectal vault.
Imaging and Laboratory Information
Hb: 13g/dl, WBC: 11.6/mm3, PMNs: 86.2%, K: 4.16 mEq/L, Na 134 mEq/L, Cr 0.62 mg/dl lipase/amylase normal. HIV negative
Clinical Differential Diagnosis
- Small bowel obstruction
- Bowel perforation
- Mesenteric adenitis from TB
- Mesenteric ischemia
Ultrasound Imaging Findings
Image 1 A) dilated small bowel loops in short axis (*), which are normally <25 mm in diameter. Image 1 B) A long-axis view of dilated small bowel (arrow) along with surrounding free fluid (arrowheads).
Differential Diagnosis Based on Imaging
Small bowel obstruction with possible perforation
Clinical Course and/or Management
The patient was fluid resuscitated, started on antibiotics, and taken for exploratory laparotomy. Surgery revealed dilated edematous small bowel with a 4mm perforation at the antimesenteric border of distal jejunum with gross contamination of the peritoneal cavity. Multiple mural nodular patches covered the whole small bowel length and mesentery, suspicious for peritoneal TB. After primary repair of the perforation and an uncomplicated post-operative course including four days of antibiotics, he was discharged home.
Small bowel obstruction and perforation, likely secondary to Tuberculosis
Intestinal obstruction (IO) is a common and potentially life-threatening surgical emergency in both resource-rich and resource-limited settings (RLS). Case series in African hospitals report IOs resulting in 4.8% of all general surgical admissions 1, with small bowel obstructions (SBO), intussusception, small bowel volvulus, intussusception, ascariasis, and adhesions 1,2 being the most common etiologies. Large bowel obstructions due to sigmoid volvulus and colonic tumors were also common 1.
IO carries a high mortality in RLS, ranging from 2.5% to 5% 1,2, with longer duration of illness prior to surgical intervention being associated with adverse outcomes1. While computed tomography (CT) is frequently employed in resource-rich settings, CT is often unavailable, unaffordable, or delayed in RLS. The diagnosis of IO is often clinical, or aided by horizontal beam abdominal radiography 2.
In a recent systemic review and meta-analysis, ultrasound was shown to have sensitivity of 92.4%, specificity of 96.5%, a positive likelihood ratio of 27.5, and a negative likelihood ratio of 0.08 in SBO diagnosis 3. The authors concluded that POCUS may be particularly useful in RLS, where CT may be unavailable or prohibitively expensive though no studies of POCUS for SBO specifically in RLS have been published. A high-frequency linear transducer may be used for young or thin patients, though curvilinear or phased array probes will suffice and may be necessary in larger patients. The entire abdomen should be evaluated in a systematic fashion, with gentle graded compression applied to displace intervening bowel gas. POCUS findings of SBO include multiple loops of small bowel dilated to greater than 25mm, altered ("to-and-fro") peristalsis, increased small bowel wall thickness, and intraperitoneal free fluid.
- Soressa U, Mamo A, Hiko D, et al. Prevalence, causes, and management outcome of intestinal obstruction in Adama Hospital, Ethiopia BMC Surg 2016;16:38.
- Ooko PB, Wambua P, Oloo M, et al. The spectrum of paediatric intestinal obstruction in Kenya. Pan Afr Med J 2016;24:43.
- Gottlieb M, Peksa GD, Pandurangadu AV et al. Utilization of ultrasound for the evaluation of small bowel obstruction: a systematic review and meta-analysis. Am J Emerg Med 2018;31:324-242.
Point-of-care abdominal ultrasound of a different patient presenting to the same emergency department with small bowel obstruction.