Measurement of forces applied during Macintosh direct laryngoscopy compared with GlideScope® videolaryngoscopy *

Laryngoscopy can induce stress responses that may be harmful in susceptible patients. We directly measured the force applied to the base of the tongue as a surrogate for the stress response. Force measurements were obtained using three FlexiForce Sensors® (Tekscan Inc, Boston, MA, USA) attached along the concave surface of each laryngoscope blade. Twenty‐four 24 adult patients of ASA physical status 1–2 were studied. After induction of anaesthesia and neuromuscular blockade, laryngoscopy and tracheal intubation was performed using either a Macintosh or a GlideScope®(Verathon, Bothell, WA, USA) laryngoscope. Complete data were available for 23 patients. Compared with the Macintosh, we observed lower median (IQR [range]) peak force (9 (5–13 [3–25]) N vs 20 (14–28 [4–41]) N; p = 0.0001), average force (5 (3–7 [2–19]) N vs 11 (6–16 [1–24]) N; p = 0.0003) and impulse force (98 (42–151 [26–444]) Ns vs 150 (93–207 [17–509]) Ns; p = 0.017) with the GlideScope. Our study shows that the peak lifting force on the base of the tongue during laryngoscopy is less with the GlideScope videolaryngoscope compared with the Macintosh laryngoscope.

[1]  R. E. Day,et al.  The Influence of Gender and Experience on Intubation Ability and Technique: A Manikin Study , 2009, Anaesthesia and intensive care.

[2]  G. Smith,et al.  Cardiovascular and catecholamine responses to laryngoscopy with and without tracheal intubation. , 1987, British journal of anaesthesia.

[3]  D. Doyle Practice Guidelines for Management of the Difficult Airway: An Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway , 2003, Anesthesiology.

[4]  B. Hindman,et al.  Manual In-line Stabilization Increases Pressures Applied by the Laryngoscope Blade during Direct Laryngoscopy and Orotracheal Intubation , 2009, Anesthesiology.

[5]  Mehmet Firat,et al.  A Comparison of the Forces Applied to a Manikin during Laryngoscopy with the Glidescope® and Macintosh Laryngoscopes , 2011, Anaesthesia and intensive care.

[6]  B. A. Austin,et al.  A new device for measuring and recording the forces applied during laryngoscopy , 1995, Anaesthesia.

[7]  Shinji Takahashi,et al.  Hemodynamic Responses to Tracheal Intubation with Laryngoscope Versus Lightwand Intubating Device (Trachlight®) in Adults with Normal Airway , 2002, Anesthesia and analgesia.

[8]  S. Inoue,et al.  Effects of lightwand (Trachlight) compared with direct laryngoscopy on circulatory responses to tracheal intubation. , 1998, British journal of anaesthesia.

[9]  A. Kovac Controlling the hemodynamic response to laryngoscopy and endotracheal intubation. , 1996, Journal of clinical anesthesia.

[10]  R. Katznelson,et al.  Heart rate/blood pressure response and airway morbidity following tracheal intubation with direct laryngoscopy, GlideScope and Trachlight: a randomized control trial , 2009, European journal of anaesthesiology.

[11]  M. Todd,et al.  Cervical Spine Motion with Direct Laryngoscopy and Orotracheal Intubation: An In Vivo Cinefluoroscopic Study of Subjects without Cervical Abnormality , 1996, Anesthesiology.

[12]  S. B. Boroojeny,et al.  Hemodynamic changes during orotracheal intubation with the glidescope and direct laryngoscope. , 2010 .

[13]  R M Harrington,et al.  Force Applied During Tracheal Intubation , 1992, Anesthesia and analgesia.

[14]  C J Snijders,et al.  Force, torque, and stress relaxation with direct laryngoscopy. , 1996, Anesthesia and analgesia.

[15]  J. R. Young,et al.  Difficult tracheal intubation: a retrospective study , 1987, Anaesthesia.

[16]  F. Xue,et al.  Comparison of hemodynamic responses to orotracheal intubation with the GlideScope videolaryngoscope and the Macintosh direct laryngoscope. , 2007, Journal of clinical anesthesia.

[17]  E. Fox,et al.  Complications related to the pressor response to endotracheal intubation. , 1977, Anesthesiology.

[18]  P. Steerenberg,et al.  Targeting pathophysiological rhythms: prednisone chronotherapy shows sustained efficacy in rheumatoid arthritis. , 2010, Annals of the rheumatic diseases.

[19]  I. R. Thomson The haemodynamic response to intubation: a perspective , 1989, Canadian journal of anaesthesia = Journal canadien d'anesthesie.

[20]  J. Laffey,et al.  Randomized controlled trial of the Pentax AWS, Glidescope, and Macintosh laryngoscopes in predicted difficult intubation. , 2009, British journal of anaesthesia.

[21]  Jacob Cohen Statistical Power Analysis for the Behavioral Sciences , 1969, The SAGE Encyclopedia of Research Design.

[22]  Y. Huang,et al.  Nasotracheal intubation using the Blind Intubation Device in anaesthetised adults with Mallampati class 3: a comparison with the Macintosh laryngoscope , 2011, European journal of anaesthesiology.

[23]  Zahid Hussain Khan,et al.  A Comparison of the Upper Lip Bite Test (a Simple New Technique) with Modified Mallampati Classification in Predicting Difficulty in Endotracheal Intubation: A Prospective Blinded Study , 2003, Anesthesia and analgesia.

[24]  J. Brimacombe,et al.  Hemodynamic Responses Among Three Tracheal Intubation Devices in Normotensive and Hypertensive Patients , 2003, Anesthesia and analgesia.

[25]  R. Caplan,et al.  Guidelines for Management of the Difficult airway An Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway , 2013 .

[26]  R. Levitan,et al.  The complexities of tracheal intubation with direct laryngoscopy and alternative intubation devices. , 2011, Annals of emergency medicine.

[27]  T. Ebert,et al.  Neurocirculatory responses to intubation with either an endotracheal tube or laryngeal mask airway in humans. , 1996, Journal of clinical anesthesia.

[28]  P. Li,et al.  Comparison of haemodynamic responses to orotracheal intubation with GlideScope® videolaryngoscope and fibreoptic bronchoscope , 2006, European Journal of Anaesthesiology.

[29]  T. Y. El-Sharkawy,et al.  Hemodynamic and catecholamine responses to laryngoscopy with vs. without endotracheal intubation , 1991, Acta anaesthesiologica Scandinavica.

[30]  R H Hastings,et al.  Force and Torque Vary Between Laryngoscopists and Laryngoscope Blades , 1996, Anesthesia and analgesia.

[31]  F. Dexter,et al.  Craniocervical Motion during Direct Laryngoscopy and Orotracheal Intubation with the Macintosh and Miller Blades: An In Vivo Cinefluoroscopic Study , 2007, Anesthesiology.

[32]  Mary Anne Fuchs Force and torque vary between laryngoscopists and laryngoscope blades , 1997 .

[33]  Yoshitsugu Yamada,et al.  Attenuation of haemodynamic responses to tracheal intubation by the styletscope. , 2001, British journal of anaesthesia.

[34]  Biing-Jaw Chen,et al.  Hemodynamic Responses To Endotracheal Intubation Comparing The Airway Scope®, Glidescope®, And Macintosh Laryngoscopes , 2009 .

[35]  P. Lachenbruch Statistical Power Analysis for the Behavioral Sciences (2nd ed.) , 1989 .

[36]  T. Stijnen,et al.  Cardiovascular effects of forces applied during laryngoscopy , 1992, Anaesthesia.

[37]  T. Stijnen,et al.  Forces applied during laryngoscopy and their relationship with patient characteristics , 1992, Anaesthesia.

[38]  J. Hall,et al.  A comparison of the forces exerted during laryngoscopy using disposable and non‐disposable laryngoscope blades , 2003, Anaesthesia.