An 83-year-old man was brought to the ED by ambulance for progressive
shortness of breath of one day duration. On arrival, he was in severe
respiratory distress and was unable to provide a detailed medical
Vital signs: blood pressure: 150/80 mm Hg; pulse: 120
irregular beats/min; respirations: 36 breaths/min;
pulse oximetry SO2 78% on room air.
On examination, there was poor air movement bilaterally. His
abdomen was distended, tympanitic to percussion, and nontender.
Bowel sounds were quiet, but present. The patient stated that he
had been constipated for six days, but had a bowel movement the
On 100% oxygen by face mask, the pulse oximetry SO2 was
ABG: pH 7.20, Pco2
59 mm Hg, 79 mm Hg, Po2
79 mm Hg
The patient was intubated.
His chest and abdominal radiographs are shown in Figure 1.
- What is this patient’s diagnosis?
Chest radiography often provides
useful information about the cause of a patient’s respiratory
failure, for example pulmonary edema or pneumonia. In this patient,
although the lungs are clear, the chest radiograph does provide
a clue to the cause of respiratory failure—a very shallow
level of inspiration (Figure 1A). Although shallow inspiration is
common in technically suboptimal, supine portable radiographs in
critically ill patients, in this case, the shallow inspiration was
due to massive abdominal distention—the cause of the patient’s
The abdominal radiograph shows
markedly distended, air-filled bowel (Figure 2). The first issue is whether this is distended
small or large bowel. One bowel segment extends horizontally across the
midabdomen (T). Small bowel tends to have a central location, although
the transverse colon is also centrally located. The mucosal indentations
of small bowel are numerous, closely spaced, and extend entirely
across the bowel lumen, in contrast to large bowel haustra. However,
markedly distended small bowel can have an appearance similar to
large bowel (Figure 3). Nonetheless, it is unusual for small bowel
to dilate to this extent (10 cm). In addition, although the mucosal
indentations are long and thin, like in small bowel, they do not
extend entirely across the bowel lumen, which is characteristic
of haustra (Figure 2). This segment of bowel is therefore the transverse
Patient 2—Abdominal radiograph
There is a markedly distended loop of bowel extending across
the midabdomen (T) and air in the rectosigmoid colon (R). A thin
soft tissue stripe extends diagonally across the abdomen (arrows).