Difficult airway management and low Bispectral Index (BIS) in a patient with left Bochdalek congenital diaphragmatic hernia (CDH)

BACKGROUND: Bochdalek congenital diaphragmatic hernia (CDH) is a developmental defect in the posterolateral diaphragm, allowing herniation of abdominal contents into the thorax causing mechanical compression of the developing lung parenchyma and lung hypoplasia. We describe a case of an adult patient with a Bochdalek hernia who underwent minimally invasive right thoracotomy Perceval bioprosthetic aortic valve replacement (AVR) requiring one-lung ventilation (OLV) on the side of the hernia. This is a complex and challenging case that brings up numerous thought-provoking anesthetic implications. To the best of our knowledge, a Pubmed search did not reveal any publication to date of difficult airway management in an adult patient with CDH. CASE PRESENTATION: The first major problem encountered was patient's crus habitus anatomical condition (exceedingly ventrally displaced trachea) Mallampati Class IV and Cormack-Lehane grade IV extremely difficult endotracheal intubation. Neither glottis nor epiglottis was visible on laryngoscopy; resulting in failed placement of the double-lumen endobronchial tube (DLT) following numerous attempts. The DLT was eventually placed via GlideScope videolaryngoscopy. Whereas the endobroncheal right lung block for left OLV was successfully placed using fiberopticscopy. The crus habitus encroached on OLV tidal volume by the cranially displaced ascending colon and left kidney. Anesthesia was maintained with remifentanil /sevoflurane; adjusted to maintain bispectral index (BIS) at 40-60. Digitally recorded BIS was 38-62 except when BIS precipitously declined to 14-38 (SR, suppression ratio < 10) for 25 min after termination of the cardiopulmonary bypass. CONCLUSIONS: We report a case essentially dealing with an anatomically distorted difficult airway in a patient with left Bochdalek CDH undergoing a complex AVR. We describe anesthetic difficulties and unforeseen issues encountered; such as an extremely difficult DLT placement.