INTRODUCTION

The Esophageal Obturator Airway (EOA) is used to help secure an airway in the unconscious unresponsive patient by blocking the esophagus and channeling air into the pharynx. Its use during cardiopulmonary resuscitation (CPR) has greatly reduced the incidence of aspiration as a complication. The EOA can be inserted without the need to visualize the airway anatomy. 

DISCUSSION

The EOA is a tube approximately 15 inches in length which is open at the top and has a blind end at the bottom. There are several side holes located in the upper third of the tube which allow air to pass from inside the tube into the pharynx. There is an inflatable cuff located just above the bottom of the tube. The EOA also has a specially designed face mask with a hole in the center for the upper end of the tube and an inflatable cuff to form a seal around the mouth and nose.

The EOA's blind end is inserted into the esophagus until the mask is seated on the face. The cuff is then inflated to seal off the stomach from the upper airway. Air is then introduced through the tube while a seal is maintained around the mouth and nose with the mask. The air then exits through the holes in the tube and from there into the pharynx.

The EOA therefore provides a more secure airway by preventing aspiration of stomach contents and channeling air into the pharynx.

The EOA is designed and intended for short term use only and should be replaced by endotracheal intubation when available. It is recommended that endotracheal intubation be performed with the EOA in place.

The EOA is designed for unconscious unresponsive patients over 16 years of age, five feet tall and/or 100 lbs. or more in weight with a need for a secure airway. It is used in respiratory arrest with or without cardiac arrest.

The EOA is contraindicated in conscious or semiconscious responsive patients as it will cause retching and vomiting by activating the gag reflex. It should not be used in children under 16 years of age or adults under five feet tall and of less than 100 pounds in weight because of size factors. It is contraindicated in patients with known histories of esophageal disease or when caustic poisons have been ingested as the pressure from the cuff may rupture or further damage the esophagus. Long term use is discouraged as the pressure from the cuff will cause necrosis of tissue.

Insertion of the tube should be done within 15 seconds as to prevent further hypoxia to the patient. If problems develop during insertion the tube should be removed and the patient manually ventilated. Then insertion should be reattempted.

Complications from use of the EOA include endotracheal intubation in which case the trachea would be occluded and no air exchange would take place. Auscultation of the lungs immediately after insertion while ventilating the patient will allow the EMT to insure correct placement of the tube. If no lung sounds are present the tube must be removed immediately and the patient manually ventilated.

Other complications include damage to or rupture of the esophagus by the EOA lubricating the tip and not using the EOA in patients with a known weak esophagus will help lessen incidence of damage as will short term use. Rupture can be prevented by using only enough air in the cuff to seat the EOA and careful monitoring of patient's condition so that the cuff may be deflated when patient begins to vomit.

The cuff must be deflated prior to removal of the EOA. Removal of the EOA should be done only with adequate suction available and the patient placed on his or her side to allow drainage of emesis as the patient will vomit on removal of the EOA.

Endotracheal intubation can and should be done prior to removal of the EOA on all patients that require a continued airway assistance. Dr. Archer 5. Gordon, M.D., Anesthesiologist, past chairman of the American Heart Association, Committee on CPR and Emergency Cardiac Care, stated "we found that. if anything, having the EOA there made it easier to intubate. The trachea was the only place the endotracheal tube could go."

SUCCESSFUL PERFORMANCE CRITERIA

• Student will correctly perform esophageal obturator intubation on an adult intubation model. Students must perform two successful intubations. Criteria for successful performance in this station is outlined below.

• Ventilate the intubation model with a bag-mask unit, demand valve or mouth-to-mouth.

• Grasp the patient's lower jaw with left thumb and index finger. Lift the head and flex the head to the chest. Hold the tongue so the tip of the airway will not push it into the posterior pharynx,

• Lubricate the tube generously and insert it with the curve up. Advance the tube cautiously until it is seated and the mask makes a tight fit over the mouth and nose.

• Ventilate via the adapter on the mask to check for proper placement. If improperly placed remove the tube and repeat the procedure to this point.

• If properly positioned inflate the cuff of the tube until resistance is met. Amount of air needed to cuff the tube will depend somewhat on the individual. Do not exceed 3035 cc. of air.

• Attach the bag-valve-mask unit and ventilate, auscultate the chest for bilateral breath sounds. Maintain seal between mask and face.

• Ventilate the patient using the esophageal obturator airway for one minute.

• Total allowable time to complete each intubation is 30 seconds. 

ESOPHAGEAL OBTURATOR AIRWAY PROTOCOL

Indications

• Unconscious

• Unresponsive

• Respiratory arrest with or without cardiac arrest

• Over 16 years of age 5 feet tall over 100 lbs. weight

Contraindications

• Conscious patient

• Patient with active gag reflex

• Patient with known history of esophageal disease

• Patient that has ingested caustic poison

• Long term use (Greater than 2 hours)

• Patient under 16 years of age

• Patients under 5 feet tall and/or under 100 lbs. weight

• Laryngectomy

Insertion

• Assemble EOA Tube inserted through mask tip lubricated and balloon inflated to check for leaks

• Hyperventilate patient with 4 full breaths

• Position at head Do not hyperextend neck Leave in neutral or flexed position.

• Thumb lift jaw and hold tongue

• Insert tube on right side in position of use

• Advance tube until mask is seated on face. If problems arise in attempting to insert, remove tube,   manually ventilate patient and then reinsert.

• Ventilate patient and auscultate the lungs.

• If EOA is in proper position, inflate balloon until resistance is met or to a maximum of 30-35 cc. of air.

Precautions

• Listen for lung sounds as it is possible to intubate the trachea and no air would be exchanged

• Do not over inflate balloon may cause esophageal rupture

• Have suction ready for immediate use at all times

• Deflate balloon and suction patient if patient begins to vomit

Removal Indication

• When patient has return of gag reflex

• When patient has endotracheal tube in place

Steps for Removal

• Turn patient on side have suction ready

• Deflate cuff

• Remove tube in one quick smooth motion

• Suction and oxygenate patient