The disposition of the cervical spine and deformation of available cord space with conventional- and balloon laryngoscopy-guided laryngeal intubation: a comparative study.

UNLABELLED: Orotracheal intubation causes cervical spine (C-spine) extension and potential (hypothetical) space available for the cord (SAC)-deformation. In the present study, we determined and compared the changes induced by conventional- and balloon laryngoscopy-guided orolaryngeal intubation in the upper C-spine's osseous unit-orientation, segmental angulation, segmental SAC-sagittal surface areas (SSAs), segmental/total posterior SAC-aspect, and segmental SAC-width. Eight healthy volunteers were enrolled. A set of neutral head position (baseline)- and two sets of intubation-lateral C-spine radiographs were obtained. Relative to baseline, both intubation techniques induced significant changes in the occiput (OCC)-, third cervical vertebra (C3)-, C4-, and C5-orientation, the OCC-C1-segmental angulation, all the segmental SAC-SSAs, and the OCC-C1-, and C1-2-posterior SAC-aspect (P < 0.05 to < 0.001); conventional intubation caused additional significant changes in C2-orientation, total (OCC through C5)-posterior SAC-aspect, and OCC-C1-SAC-width (P < 0.05 to < 0.001). Relative to conventional intubation, balloon-assisted intubation caused less change in C3-orientation and C2-3-SAC-width (P < 0.05), and less reduction in OCC-C1-, C1-2-, and C4-5-SAC-SSAs (P < 0.05 to < 0.01). Orotracheal intubation should be cautiously performed in patients with space-occupying upper-C-spine-SAC lesions, even if there is no concomitant osseous/ligamentous pathology. In such cases, balloon laryngoscopy may be chosen over the conventional technique, because it causes less SAC deformation. IMPLICATIONS: This study shows that direct laryngoscopy-guided orotracheal intubation causes deformation of the upper cervical space available for the cord, even in the absence of cervical spine instability. These effects are attenuated with balloon laryngoscopy, and thus, its use is recommended in patients with space-occupying lesions within the spinal canal.

Balloon versus conventional laryngoscopy: a comparison of laryngoscopic findings and intubation difficulty.

We compared laryngeal aperture (LA) exposure and endotracheal intubation difficulty scale (IDS) scores between balloon-assisted and conventional laryngoscopy. Thirty-two anesthetized and paralyzed elective surgery patients underwent laryngoscopy with a standard number 4 and a modified number 4 curved blade carrying a 6F Fogarty catheter. The balloon laryngoscopy technique included modified blade tip insertion into the vallecula, Fogarty catheter balloon inflation with 2 mL of air, and blade elevation until LA exposure maximization. On maximal LA exposure with both blades, the LA views were videotaped with a camcorder aligned to blade light source and the exposed LA areas measured electronically. The IDS scores were determined on passing the tip of an endotracheal tube through the vocal cords. The patient head position, the angle of laryngoscope handle elevation, and the time available for airway instrumentation were standardized. The data from 27 patients were analyzed. The exposed LA areas were significantly larger with balloon laryngoscopy than conventional (median, interquartile range: 0.94, 0.65-1.80 cm(2) vs. 0.52, 0.39-1.46 cm(2) respectively) (P = 0.027), and the IDS scores lesser (median, interquartile range: 0, 0-1 vs. 1, 0-2 respectively) (P = 0.012). We concluded that balloon laryngoscopy facilitates elective airway management.