OT-118
Report of three cases of infants with pyloric stenosis using apneic oxygenation via nasal cannula technique, who did not have significant desaturation during intubation despite apnea for more than a minute.
Soneru C, Falcon R, Petersen T, Lester A, Stalls C, Hurt H
UNM, Albuquerque, NM, USA
Infants with pyloric stenosis are at risk of critical desaturation due to small FRC and high metabolic rate. They are considered to have full stomachs. Mask ventilation during intubation attempts might increase their risk of aspiration. Techniques that prolong the time to desaturation might increase anesthetic safety. We present three cases where apneic oxygenation via nasal cannula prevented desaturation for longer than one minute in infants with pyloric stenosis. The reported time to intubation was defined as the interval between removal of the mask from the face and confirmation of intubation upon auscultation of breath sounds.
The first patient was a 5 week old male, 3.85 kg, 53.3cm. The room air oxygen saturation was 92%, and the preoxygenation saturation was 100% at an expiratory oxygen concentration of 92%. Induction was achieved with 15 mg Propofol and 3 mg Rocuronium. The time to intubation was 1 minute 37 seconds. The lowest observed oxygen saturation was 97%.
The second patient was an 8 week old male, 4.13 kg, 62 cm. The room air oxygen saturation was 96%, and the preoxygenation saturation was 100% at an expiratory oxygen concentration of 90%. Induction was achieved with 12 mg Propofol and 3 mg Rocuronium. The time to intubation was 1 minute 17 seconds. The lowest observed oxygen saturation was 100%.
The third patient was a 3 week old male, 2.9 kg, 49.5 cm. The room air oxygen saturation was 100%, and the preoxygenation saturation was 100% at an expiratory oxygen concentration of 90%. Induction was achieved with 12 mg Propofol and 3 mg Rocuronium. The time to intubation was 1 minute 32 seconds. The lowest observed oxygen saturation was 99%.
Apneic oxygenation is based on the uptake of the oxygen in the lungs in a non-ventilated state. In adults, the lungs absorb a greater volume of oxygen (250 ml/min in an adult), than the released volume of carbon dioxide (8-20 mL/min). The majority of carbon dioxide is buffered in the blood stream. With the imbalanced volumes of absorbed and released gases, there is a lower than atmospheric pressure in the lungs, creating a passive movement of gases from pharynx to alveoli. If the gas in the pharynx is enriched in oxygen, a higher amount of oxygen can be passively delivered to the lungs for absorption therefore prolonging the time to hemoglobin desaturation.
One study in intubated pediatric patients found that apneic oxygenation prevented hypoxia in children for at least 10 minutes, but infants may become hypoxic after only 2 min.
Our three patients did not experience significant desaturation. Apneic oxygenation is a documented effective technique that prolongs the time to critical desaturation in the adult population. Several pediatric studies support these results. Larger clinical trials in the pediatric population are in progress.
1.Bhagwan SD. Levitan's no desat with nasal cannula for infants with pyloric stenosis requiring intubation. PMID: 23384304
2.Weingart , Levitan. Preoxygenation and prevention of desaturation during emergency airway management. PMID: 22050948
3.Cook TM et al. Changes in blood-gas tensions during apnoeic oxygenation in paediatric patients. PMID: 9861115
4.Kernisan G et al. Apneic oxygenation in pediatric patients. Anesthesiology 1987;3:A521
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