Hemodynamic and Humoral Response to Intubation with Double-lumen Endotracheal Tubes Versus Single-lumen Tubes Combined with an Endobronchial Blocker: A Randomized Clinical Trial

Introduction: Insertion of endotracheal tubes, especially large and relatively inflexible double-lumen tubes, provokes cardiovascular and humoral responses which can cause complications. Bronchial blockers, combined with conventional single-lumen tubes (SLT), serve as alternatives to double-lumen tubes (DLT) and may provoke less hemodynamic response. Methods: Forty adults scheduled for elective thoracic surgery requiring single-lung ventilation were randomly assigned to DLT or SLT combined with EZ-Blocker (EZ), a bronchial blocker. Heart rate and arterial blood pressure were recorded before induction of anesthesia, before laryngoscopy, after laryngoscopy, and one minute after intubation. Epinephrine, norepinephrine, and cortisol serum concentrations were assessed one minute after intubation. Results: Pre-laryngoscopy values were comparable in both groups. Mean arterial pressure significantly increased in both groups during intubation. The maximum value during intubation was significantly higher with DLT (121 ± 17 mmHg), compared to bronchial blocker (105 ± 18 mmHg, P=0.022). Heart rate increased significantly during intubation in both groups (DLT from 68 ± 9 to 86 ±11, P<0.001, bronchial blocker from 72 ±11 to 87 ± 16, P=0.002), but the increase did not differ between the groups (P=0.76). Epinephrine, norepinephrine, and cortisol serum concentrations did not increase significantly from baseline values and did not differ between the treatment groups. Conclusion: Insertion of DLT increases blood pressure more than placement of a SLT combined with bronchial blocker. However, the difference is probably not clinically important. Furthermore, there were no significant differences in heart rate or catecholamine concentrations. Clinicians should consider other factors when choosing between airway options for single-lung ventilation.