The management of difficult intubation in infants: a retrospective review of anesthesia record database

We retrospectively reviewed the anesthesia records of infants < 1 year of age for elucidating the incidence of difficult intubation and airway management in a single general hospital. The electronic data records from a total of 753 consecutive anesthesiological procedures in 513 different infants were analyzed. After excluding data with a lack of records of laryngoscopic findings, a total of 497 procedures (389 different infants) with either remarks of difficult intubation (requiring > 10 min for tracheal intubation) or records of Cormack-Lehane grade were included. Demographic data are median age 5 (range, 0-11) months, height 61 (33-84) cm, body weight 6.0 (1.1 - 11.8) kg. The number of cases with ASA physical status I, II, III and IV was 182 (36.6 %), 135 (27.3 %), 177 (35.5 %) and 3 (0.6 %), respectively. Cormack-Lehane grade 1, 2, 3 and 4 was seen in 450 (90.5 %), 32 (6.4 %), 6 (1.2 %) and 6 (1.2 %) cases, respectively. Document of difficult intubation was found in 12 cases (2.4 %, 10 different infants) with a lack of record of Cormack-Lehane grade in 3 cases. Of these 10 infants, nine had multiple congenital anomalies including heart diseases and cleft palate. Without premedication, general anesthesia was induced with intravenous midazolam or sevoflurane in the 12 cases. Tracheal intubation was performed after disappearance of spontaneous respiration except three cases who were intubated in the awake state or under sedation. Elapsed time from induction of anesthesia to intubation was 17 (14-29) min. Although mask ventilation was adequate in all cases, two cases (one infant) developed hypoxia and bradycardia during tracheal intubation. No remarkable decrease of SpO₂ or bradycardia less than 100 bpm was detected in other cases. In conclusion, we found difficult intubation in 2.4 % of infants undergoing general anesthesia. Although muscle relaxants are useful for facilitating tracheal intubation, it should be carefully used with the preparation of other airway devices in infants with predicted difficult intubation.