Revisited: Haemodynamic Instability and Endocrine Response During Endotracheal Tube-Placement. A Prospective, Randomized Trial Using Topical Lidocaine and a Lightwand

Abstract

Endotracheal intubation via direct laryngoscopy frequently provokes cardiovascular side-effects. Although us- ing a lightwand intubation device reduces laryngeal stimulation, previous reports indicated a similar stress response com- pared to classical laryngoscopy. We hypothesized that endotracheal tube (ET) placement itself elicits haemodynamic in- stability and that topical anaesthesia can attenuate this response. Methods: 30 patients were randomized to three groups (n = 10 each). After induction of general anaesthesia (fentanyl, etomidate, vecuronium) 5 ml of test solution was applied to laryngo-tracheal structures via a lightwand guided EDGAR- Tube ® . Control group received 5 ml saline 0.9%, group lido 1% 5 ml lidocaine 1%, and group lido 2% 5 ml lidocaine 2%. After 2 minutes of bag-mask ventilation lightwand guided ET placement was performed. Invasive systolic arterial pres- sure (SAP, mmHg), heart rate (HR, bpm) and arterial plasma concentrations of catecholamines ((adr)(nor), pcg ml-) were determined. Results: After ET placement control group patients showed increased HR and SAP (meanHR = 15.3; meanSAP = 45.6) compared to both lido groups (� HR: lido1%/2% = 5.8/3.7; � SAP: lido1%2% = 8.7/13.0). Catecholamine concen- trations also increased only in the control group (mean � (adr) = 101.43; � (nor) = 89.41) but not in lido groups (� (adr): lido1%/2% = -12.93/7.05; � (nor): lido1%/2% = -6.61/-30.55). Effect size calculation indicated strong clinical effects of topical lidocaine for almost all variables (ES > 0.8). Conclusion: ET placement into the non-anaesthesized trachea causes haemodynamic and endocrine stress even if direct laryngoscopy is omitted. Topical anaesthesia effectively reduces this response.