Air Leak in a Pediatric Case—Don’t Forget to Check the Mask!

Elvera L. Baron, MD, PhD; Barbara M. Dilos, DO

Letter to the Editor:

gap in pediatric mask

Figure 1. Note the apparent small gap (see red
circular outline) in the pediatric mask on the left
side of the figure.

To the Editor:

Scrupulous anesthesia equipment check is part of a routine pre-operative checklist for all pediatric cases. We describe a case of a defective face mask, the integrity of which was not assessed prior to use. This had the potential to result in the adverse outcome of a pediatric patient if not promptly detected.

An otherwise healthy 3-week old infant presented for pyloromyotomy under general anesthesia. Despite pre-oxygenation and normal vital signs, efforts to bag-mask ventilate the infant via face mask during a rapid sequence induction where the first attempt at intubation was not successful proved to be inadequate and unsuccessful. An appropriately sized oral airway was placed. The anesthesia providers detected a sound suggesting a leak. The appropriately sized bubble gum flavored latex-free face mask was firmly re-applied to the patient’s face, with concurrent chin lift-jaw thrust maneuver in order to maximize ventilation, yet no chest rise or end tidal CO2 were noted. Again, a leak in the circuit was suspected, and both the machine and the circuit were quickly re-examined. A loud leak around the face mask was heard despite adequate seal between face mask and patient’s face, with precipitant hypoxemia. Leak in the mask itself was presumed. After the defective mask was replaced by another one of the same size, ventilation efforts became markedly improved, leading to stabilization of the patient’s vital signs. The patient then underwent intubation, maintenance, and emergence from anesthesia uneventfully, and fully recovered in the post-anesthesia care unit without any additional concerns.

After conclusion of the surgery, closer examination revealed two small defects at the brim of the face mask, accounting for resultant air leak during attempted hand ventilation. Though the mask was examined pre-operatively for its ability to hold air in the inflatable cushion of the mask, this did not preclude the leak from occurring since the defect responsible for the leak was found at the brim of the mask (see Figure 1). The anesthesiology team examined several additional masks from the same batch of the same size, and did not discover similar defects.

The supplier of the mask was contacted. Visual inspection confirmed that the glue used to seal the air cuff of the face mask had multiple gaps in it between the crown and the bladder of the mask, while no leak was detected in the cushion itself. Since samples were re-inflated and compressed by hand, potential root causes for this failure mode included operator error setting up adhesive dispense quantity. Several improvements were reportedly made since the production of this lot with controls in place to mitigate this failure mode.

The risk of cardiac arrest in pediatric anesthetic cases is approximately 1.4 in 10,000.1 Infants accounted for 55% of all anesthesia-related arrests, with those younger than 1 month of age having the greatest risk. Eighty-two percent of cardiac arrests occurred during induction of anesthesia; bradycardia, hypotension, and a low SpO2 frequently preceded these arrests. Respiratory mechanisms leading to cardiovascular collapse included laryngospasm, airway obstruction, and difficult intubation, in decreasing order. In most cases, the laryngospasm occurred during induction. Infants have a reduced margin for error. Since hypoxia from inadequate ventilation is exacerbated by neonatal and pediatric respiratory physiology, it remains a common cause of perioperative morbidity and mortality. Pulse oximetry and capnography assume an even more important role in infants as compared to older children or adults. Specifically contoured face masks are designed to minimize dead space and to aid in adequate ventilation efforts.2 It is crucial to select equipment appropriate for age and size as the infant airway easily becomes obstructed. Oral airways may help forwardly displace an oversized tongue.

Compression of submandibular soft tissues should be avoided during mask ventilation to prevent further upper airway obstruction.

Based on our experience, if an air leak is heard or suspected during attempted bag-mask ventilation, we recommend to examine the source of such air leak systematically, rapidly, and thoroughly. Once the machine and circuit are found to function properly, the leak source is then narrowed to the face mask itself. We advise adding inspection of the face mask and assessment of its integrity as part of the routine pre-operative checklist for all cases.

Elvera L. Baron, MD, PhD, is a Fellow in the Adult Cardio-Thoracic Anesthesiology Program in the Department of Anesthesiology at The Mount Sinai Hospital, New York, NY.

Barbara M. Dilos, DO, is an Assistant Professor, Director of Pediatric Anesthesia in the Department of Anesthesiology at Elmhurst Hospital Center, Queens, NY.

Neither author has any financial conflicts of interest to disclose.


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