34: Laryngeal Mask Airway

INTRODUCTION

The laryngeal mask airway (LMA) consists of a soft elliptical mask with an inflatable cuff that is attached to a flexible airway tube. The mask covers the laryngeal opening with an inflatable cuff that occludes the esophagus. It can provide positive pressure ventilation. To quote the 2011 American Academy of Pediatrics/American Heart Association Textbook of Neonatal Resuscitation, when you “can't ventilate and can't intubate,” the device may provide a successful rescue airway.

I. INDICATIONS

1. Ineffective face mask ventilation in neonates with the following:

   1. Abnormal facial anatomy (eg, cleft lip, cleft palate)

   2. Unstable cervical spine (eg, osteogenesis imperfecta, arthrogryposis, trisomy 21)

   3. Upper airway obstruction (eg, Pierre-Robin sequence, micrognathia, large tongue, reductant tissues, and oral, pharyngeal, or neck tumors)

2. Rescue procedure after failed intubation or intubation not feasible.

3. For short-term positive pressure ventilation in neonatal intensive care unit.

4. Resuscitation (delivery room or other) when face mask and endotracheal intubation fail. If necessary, chest compressions can be attempted with LMA in place.

II. EQUIPMENT

Appropriate LMA (size 1 for neonate; see Figure 34–1; reusable and disposable types), lubricant (water-soluble), 5-mL syringe, gloves.

III. PROCEDURE

1. LMA limitations. To suction meconium, to give intratracheal medications (may leak), prolonged ventilator support (not enough evidence, high ventilation pressures are needed, and air may leak), extremely small infants (<1500 g), when chest compressions are performed (ETT preferred, but if not possible chest compressions can be attempted with LMA).

2. With significant gastric distension. Consider a temporary orogastric tube to decompress the stomach and remove.

3. The LMA covers the laryngeal opening. The inflated cuff conforms to the hypopharynx and occludes the esophagus. See Figure 34–2.

4. Use size 1 LMA. Commercially available masks are designed for infants >2000 g, but can be used in smaller infants (>1500 g) if needed.

5. Follow standard precautions. Gloves, eye protection, etc.

6. Check cuff for leakage by inflating with 2–3 mL of air. Fully deflate the cuff before insertion.

7. Position patient on back, stand behind the head, put in the “sniffing position.”

8. Lubricate the back of the mask of LMA if needed.

9. Hold LMA like a pencil and open the baby's mouth.

10. With the aperture facing anteriorly, insert the LMA against hard palate and using your index finger guide the LMA. Insert until resistance felt.

11. Inflate the mask with 2–4 mL of air to provide adequate seal. Do not exceed maximum recommended by manufacturers of 4 mL of air in a size 1 mask.

12. Watch for the rise of LMA cuff during inflation.

13. Connect the end of tube to ...