Comparison of 3 Direct Laryngoscopes: Inscope DL Blade Size 3.5 and DL Blade 3.5 Sun-Med GreenLine®/D™ to DL Blade 3 Sun-Med GreenLine®/D™ for Tracheal Intubation in Patients Undergoing Lumbar Spine Surgery, a Prospective Randomized Study

Laryngoscopy is a common medical procedure used during elective and emergency intubations. The procedure is performed with either a direct or video laryngoscope with the device selected dependent on tool availability, provider (i.e. anesthesiologist, emergency physician, ENT physician, paramedic, etc.) preference, patient characteristics, and intubation difficulty. The direct laryngoscope technique involves a line-of-sight view from the patient's mouth to vocal cords along the blade of the scope. The direct laryngoscopy technique is the oldest technique associated with intubation. However, despite continuous improvements to direct laryngoscope size and shape since its inception in the late 19th century, no improvement yet addresses one major problem with airway visualization: the provider will experience a difficult intubation if liquids (i.e. gastric content, blood, mucus, etc.) obstruct the view.

The Sun-Med GreenLine®/D™ Macintosh is a line of disposable direct Macintosh laryngoscopes. It features a stainless steel blade and polycarbonate light-pipe to direct light into the airway. The handle, with integrated batteries and LED light, and blade are separately packaged prior to use. The GreenLine®/D™ Macintosh line is available in the standard sizes (0, 1, 2, 3, 4) and a new size built to improve blade sizing for many adults 3.5 when a Mac 3 is too short, but a Mac 4 is too large. The GreenLine®/D™ Macintosh does not feature integrated suction.

The Inscope Direct Laryngoscope (developed by Inscope Medical Solutions) is a new disposable direct laryngoscope with two integrated and controllable (flow on/off) suction pathways. By integrating controllable suction with two independent pathways into the laryngoscope, the provider is able to select the primary (blade tip) suction pathway to clear secretions ahead of the laryngoscope and the secondary (at blade mid-length, below blade) to prevent and clear fluids that may re-accumulate during the procedure. Integrating the suction into the device prevents the common current practice of "juggling" the current suction catheter and endotracheal (breathing) tube in one hand while holding the patient's airway open with the other hand. While the incidence of aspiration of fluids into the lungs as a result of poor airway fluid management is low, the outcomes associated with this complication are very poor.

The Inscope Direct Laryngoscope has been developed as a Macintosh 3.5 sized blade to meet the size requirements of the majority of patients. This assumption is backed up by a trend among disposable direct laryngoscope manufacturers toward the 3.5 blade size, with at least 5 creating a 3.5 blade, including Teleflex, Sun-Med, Flexicare, Mercury Medical, and Curaplex.

This study will compare the Inscope Direct Laryngoscope (blade size 3.5) with the currently used standard single-use Sun-Med Greenline/D Macintosh laryngoscopes DL-blade mac size and Sun-Med Greenline/D-blade size 3.5.