///2009 Abstract Details
2009 Abstract Details2019-08-03T15:55:31-06:00

Heliox Therapy and Tracheostomy in a Parturient with Severe Subglottic Stenosis

Abstract Number: 58
Abstract Type: Case Report/Case Series

Jessica Rock MD1 ; Jessica Hathaway MD2; Michael Makaretz MD3; Ted Rintel MD4


Severe upper airway obstruction presents a challenge to providers even in otherwise uncomplicated patients. When the pulmonary changes of pregnancy and consideration of the well-being of the fetus are added, management requires a coordinated effort between obstetrical, anesthesia, and surgical providers. We present the case of a pregnant patient with severe subglottic stenosis who underwent tracheostomy under local anesthesia and monitored anesthesia care with heliox provided via nasal cannula.

Case Report

A 28-yr-old G2P1 at 33 weeks gestation was transferred from an OSH after discovery of 80-90% subglottic stenosis, with an estimated tracheal diameter of 3-4 mm. Past medical history included GERD, congenital lymphedema, and dyspnea during this pregnancy, originally diagnosed as asthma. Her first pregnancy was uncomplicated and resulted in NSVD. The current pregnancy was otherwise complicated only by early subchorionic bleed.

Pre-procedure, the patient had increased work of breathing but no stridor or audible upper airway noises. SpO2 on room air was 98%. A helium:oxygen ratio of 80:20 at 2LPM was provided to the patient via nasal cannula. The patient indicated a subjective improvement in work of breathing with the initiation of heliox therapy. SpO2 was 100%.

Tracheostomy was performed with local anesthesia and midazolam/propofol sedation, with heliox provided throughout. Fetal monitoring was performed continuously and staff and equipment were available for potential emergency cesarean section. The procedure was well-tolerated and was accomplished without complication and with minimal blood loss. Fetal heart rate was 130s-150s throughout the procedure. The patients work of breathing improved significantly after placement of the tracheostomy tube.

The patient was observed overnight in the ICU in consideration of staff familiarity with care of a fresh tracheostomy. The patient did not otherwise require ICU monitoring. Her recovery was uneventful, with no airway or obstetrical complications. Plan was for definitive treatment of her stenosis after delivery.


Preparation for and safe execution of this procedure required consideration of and preparation for multiple risks: airway loss, preterm delivery, fetal exposure to medications, and patient consent and cooperation. The case also required understanding of the physics of air flow through tracheal stenosis and the respiratory changes of pregnancy. The low density of helium allows greater flow in turbulent areas, but it also lowers Reynolds number and increases the chance that flow will be laminar, improving overall flow through an area of decreased diameter, leading to a decrease in work of breathing. This change was particularly important in our patient given the increase in metabolic rate and minute ventilation during pregnancy and her severe degree of tracheal stenosis.


Kass, J. E. (2003). "Heliox redux." Chest 123(3): 673-6.

SOAP 2009