Acid Perfusion Test

Also called the Bernstein test, this procedure helps to distinguish pain caused by esophagitis (burning epigastric or retrosternal pain that radiates to the back or arms) from pain caused by angina pectoris or other disorders. It requires perfusion of saline and acidic solutions into the esophagus through a nasogastric (NG) tube.

Purpose

• To distinguish chest pains caused by esophagitis from those caused by cardiac disorders.

Patient Preparation

• Tell the patient that this test helps determine the cause of chest pain.
• Explain the following restrictions: no antacids for 24 hours before the test and no food, fluids, or smoking for 12 hours before the test.
• Describe the test, including who will perform it and where and its duration.
• Explain that the test involves passing a tube through his nose into the esophagus and that he may experience some discomfort, a desire to cough, or a gagging sensation during intubation.
• Tell him that liquid is slowly perfused through the tube into the esophagus and that he should immediately report any pain or burning during perfusion.
• Just before the test, check the patient's pulse rate and blood pressure.
• Ask him if he's experiencing any chest pain and, if so, to describe it

Procedure And Posttest Care

• After the patient is seated, insert an NG tube that has been marked 12" (30 cm) from the tip into his stomach. Attach a 20-ml syringe to the tube and aspirate stomach contents. Withdraw the tube into the esophagus (to the 12" mark).
• Hang labeled containers of normal saline solution and a prescribed acidic solution on an I.V. pole behind the patient; then connect the NG tube to I.V. tubing.
• Open the line from the normal saline solution, and infuse it at a rate of 60 to 120 drops/minute. Continue perfusion for 5 to 10 minutes.
• Ask the patient if he's experiencing any discomfort and record his response.
• Without the patient's knowledge, close the line from the normal saline solution and open the line from the acidic solution. Infuse the acidic solution into the esophagus at the same rate used for the saline solution. Continue perfusion for 30 minutes.
• Ask the patient again if he's experiencing any discomfort, and record his response.
• If the patient experiences discomfort, close the line from the acidic solution immediately and open the line from the normal saline solution. Continue to perfuse this solution until the discomfort subsides.
• Unless perfusion of the acidic solution is to be repeated, the NG tube is withdrawn.
• If the patient complains of pain or burning, administer an antacid. If he complains of a sore throat, provide soothing lozenges or an ice collar.
• Tell him that he may resume his usual diet and any medications withheld for the test.

Precautions

• The acid perfusion test is contraindicated in patients with esophageal varices, heart failure, acute myocardial infarction, or other cardiac disorders.
• During intubation, make sure the tube enters the esophagus and not the trachea. Withdraw the tube immediately if the patient develops cyanosis or paroxysmal coughing.
• Assess the patient's pulse rate and rhythm to detect any arrhythmias that may develop.
• Clamp the tube before removing it to prevent aspiration of fluid into the lungs.

Normal Findings

Absence of pain or burning during perfusion of either solution indicates a healthy esophageal mucosa.

Abnormal Findings

In patients with esophagitis, the acidic solution causes pain or burning, and the normal saline solution should produce no adverse effects. Occasionally, both solutions cause pain in patients with esophagitis, but they may cause no pain in patients with asymptomatic esophagitis.

Interfering Factors

• Failure to adhere to pretest restrictions