B

Figure 31-1. A. Upright abdominal radiograph of small

bowel obstruction. Note the multiple air-fluid levels and

the "string of pearls" sign (arrow). B. Abdominal CT scan

demonstrating bowel obstruction.

PROCEDURES

Most intestinal obstructions benefit from decompression with a nasogastric (NG) tube. Placement of an NG

tube is uncomfortable for the patient and should be

carried out in the following manner to decrease pain

and anxiety:

1. Sit the patient upright with the head of the stretcher at

90°. Determine which nostril is less congested by having

the patient blow the nose on both sides. Inject viscous

lidocaine into the nostril or alternatively spray benzo ­

caine into the nostril and mouth.

INTESTINAL OBSTRUCTION

Clinical suspicion of bowel

obstruction

IVF, NGT,

admit, surgical

consultation

High clinical

suspicion: obtain

CT scan

Low clinical

susp icion: search

for alternate

etiology

Figure 31-2. I ntestinal obstruction diag nostic algorithm. CT, computed tomography;

IVF, Intravenous fluids; NGT, nasogastric tube.

2. Insert the NG tube straight back until the tip is at the

posterior pharynx, and then pause. Give the patient a

glass of water with a straw. Instruct the patient that as

they begin to swallow the water, you will insert the tube.

3. Insert the tube as the patient swallows. The tube is

inserted to approximately 30-40 em. Coughing after

placement suggests inadvertent placement in the lung.

4. Check the location of the tube by inserting 60 mL of air

and listening over the stomach for gurgling. Aspiration

of stomach contents will also indicate that the tube is in

the proper location. An abdominal radiograph should

be used to confirm the correct location.

5. Tape the tube securely to the nose. Place the tube to low

intermittent suction (LIS).

MEDICAL DECISION MAKING

Diagnosis of intestinal obstruction relies on careful patient

history, physical exam, and interpretation of imaging studies (Figure 31-2). Obstruction should be considered in any

patient with a history of prior surgeries, as adhesions are

the leading cause. Do not rule out obstruction based on the

presence of flatus or bowel movements or the lack of vomiting, as these findings may develop later. If clinical suspicion is high enough, consider starting with a CT scan

instead of radiographs. If the patient appears acutely ill,

begin with resuscitation and consult a surgeon immediately even if imaging studies have not been completed.

TREATMENT

Establish intravenous (IV) access promptly and begin

administration of fluids. An initial bolus of 1-2 L of

0.9 normal saline is appropriate, but some patients may

require more aggressive fluid resuscitation to replace thirdspaced volume loss. Antiemetics should be given (ondansetron 4 mg IV, prochlorperazine 10 mg IV, promethazine

25 mg IV). Consider narcotic pain medications (morphine

4 mg IV, hydromorphone 0.5 mg IV) and repeat as needed.

An NG tube should be inserted once the diagnosis of

obstruction has been made and should be placed to low

CHAPTER 31

intermittent suction (LIS). This results in decompression

of the bowel lumen, provides symptomatic relief, and may

avoid the need for surgery. Broad-spectrum antibiotics

that cover gram-negative and anaerobic organisms (eg,

piperacillin-tazobactam, ciprofloxacin plus metronida ­

zole) should be given in the presence of fever, peritonitis,

or evidence of strangulation. Surgical consultation should

be obtained in case the patient requires surgical intervention. For patients with adynamic ileus, treatment involves

cessation of any narcotic medications and initiation of

motility agents (eg, metoclopramide).

DISPOSITION

..... Admission

All patients with intestinal obstruction require admission,

either to a surgical service or a medicine service with a

surgeon on consult. Most patients can be admitted to floor

units.