ผลขององศาการดัดลวดนำในท่อช่วยหายใจต่อระยะเวลาการใส่ท่อช่วยหายใจโดยการส่องผ่านกล่องเสียงโดยตรง: การศึกษาแบบสุ่มไขว้ในสถานการณ์จำลอง

Poorich  Jiradetpitaksa; Ravipol Jurjai; Patcharee Duongthong

Authors

Poorich Jiradetpitaksa Emergency Department, Saraburi Hospital
Ravipol Jurjai Emergency department, Saraburi hospital https://orcid.org/0000-0002-1402-3348
Patcharee Duongthong Emergency Department, Saraburi Hospital https://orcid.org/0009-0007-9130-9300

Keywords:

Intubation, Stylet, Patient Simulation, Manikin, Time Factor

Abstract

Introduction
Proper preparation of stylet angulation is a critical factor for rapid endotracheal intubation. However, clinical guidelines regarding the optimal stylet angulation for this procedure remain undefined.
Objectives
To study the effect of different endotracheal tube stylet bend angles on intubation time, first-attempt success rate, and intubation failure rate.
Method
A randomized crossover simulation study was conducted to compare the effect of various stylet angles on intubation time. Seventy medical personnel with varying levels of experience at Saraburi Hospital participated between January 1st and December 31st, 2025. Participants performed intubations using a randomized sequence of predetermined stylet angles. The primary outcome was intubation duration, while secondary outcomes included the number of attempts and intubation failure rates.
Results
The adjusted mean time (aMT) for the 15° angle was 18.2 seconds (95% CI, 15.9–20.4). Intubation durations with 30° and 45° stylet bend angles were significantly shorter than with a 15° stylet bend angle (aMT = 15.4 s; 95% CI, 13.1–17.6 and aMT = 15.5 s; 95% CI, 13.2–17.8, respectively), with no intubation failures. In contrast, 75° and 90° angles required significantly longer durations (aMT = 21.1 s; 95% CI, 18.8–23.3 and aMT = 26.0 s; 95% CI, 23.7–28.2, respectively), with a failure rate of 1.4%. First-attempt success rates did not differ significantly across all angles.
Conclusion
A stylet bend angle of 30°–45° requires the least amount of intubation time in a simulation model when compared to other angles. Stylet angulation does not significantly impact the first-attempt success rate.

References

Roberts JR, Custalow CB, Thomsen TW, Chanmugam A, Chudnofsky CR, Deblieux P, et al. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia: Elsevier; 2018: 65.

Tintinalli JE, Ma OJ, Yealy DM, Meckler GD, Stapczynski JS, Cline DM, et al. Tintinalli’s emergency medicine: a comprehensive study guide. 9th ed. New York: McGraw-Hill Education; 2020: 181-5.

Goto T, Gibo K, Hagiwara Y, Brown DF, Hasegawa K. Multiple failed intubation attempts are associated with decreased success rates on the first rescue intubation in the emergency department: a retrospective analysis of multicentre observational data. Scand J Trauma Resusc Emerg Med 2015;23:5. doi:10.1186/s13049-014-0085-8

Mort TC. Emergency tracheal intubation: complications associated with repeated laryngoscopic attempts. Anesth Analg 2004;99(2): 607-13. doi:10.1213/01.ANE.0000122825. 04923.15.

Nutbeam T, Boylan M, Leech C, Bosanko C. ABC of prehospital emergency medicine. 2nd ed. Chichester: Wiley-Blackwell; 2023: 27-37.

Walls RM, Murphy MF. Manual of emergency airway management. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2012.

de Alencar JCG, Marques B, Marchini JFM, Marino LO, Ribeiro SCDC, Bueno CG, et al. First-attempt intubation success and complications in patients with COVID-19 undergoing emergency intubation. J Am Coll Emerg Physicians Open 2020;1(5):699-705. doi:10.1002/emp2.12219.

Levitan RM, Pisaturo JT, Kinkle WC, Butler K, Everett WW. Stylet bend angles and tracheal tube passage using a straight-to-cuff shape. Acad Emerg Med 2006;13(12):1255-8. doi:10.1197/j.aem.2006.06.058.

Golaghaie F, Momeni R, Jafarimanesh H, Golestanieraghi M, Golitaleb M, Rafiei F. Impact of stylet bend angle on the performance of orotracheal intubation by emergency response nurses: a randomized simulation study. Eurasian J Emerg Med 2018;17(2):45-9. doi:10.5152/eajem.2018. 78942.

Zhang Y, Guo H, Hu Z, Wang L, Du H. Comparison of the success with two bending angles for lighted stylet intubation in children: a prospective randomised study. Paediatr Anaesth 2022;32(4):531-8. doi:10.1111/pan.14398.

Lee J, Kim JY, Kang SY, Kwak HJ, Lee D, Lee SY. Stylet angulation for routine endotracheal intubation with McGrath videolaryngoscope. Medicine (Baltimore) 2017;96(7):e6152. doi:10.1097/MD.0000000000006152.

Jones PM, Turkstra TP, Armstrong KP, Armstrong PM, Cherry RA, Hoogstra J, et al. Effect of stylet angulation and endotracheal tube camber on time to intubation with the GlideScope. Can J Anaesth 2007;54(1):21-7. doi:10.1007/BF03021895.

Won D, Lee JM, Lee J, Hwang JY, Kim TK, Chang JE, et al. A pilot study comparing three bend angles for lighted stylet intubation. BMC Anesthesiol 2021;21(1):148. doi:10.1186/s12871-021-01369-8.

Hilton MT, Carlson JN, Chan S, Phrampus PE. Impact of stylet use in a simulated difficult airway model. Am J Emerg Med 2013;31(3): 578-80. doi:10.1016/j.ajem.2012.09.014.

Jongaramrueng N, Teerasahakul P. Comparison of intubation performance with different airway manikins by inexperienced hands: a cross-over manikin study. J Med Biosci 2024;6:e267687.

Benumof JL, Dagg R, Benumof R. Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology 1997;87(4):979-82. doi:10.1097/00000542-199710000-00034.

Sakles JC, Chiu S, Mosier J, Walker C, Stolz U. First-pass success without hypoxemia is associated with reduced adverse events in adult patients intubated in the Emergency Department. Ann Emerg Med 2017;69(1):1-10.

Ahmad I, El-Boghdadly K, Iliff H, Dua G, Higgs A, Huntington M, et al. Difficult Airway Society 2025 guidelines for management of unanticipated difficult tracheal intubation in adults. Br J Anaesth 2026;136(1):283-307. doi:10.1016/j.bja.2025.10.006.

York S, Yates A, Frisch A. Emergency medicine resident trauma intubation success and prior intubation experience. J Emerg Med 2023;64(2):230-5. doi:10.1016/j.jemermed.2022.12.006.

Thomas J, Crowe R, Schulz K, Wang HE, De Oliveira Otto MC, Karfunkle B, et al. Association between emergency medical service agency intubation rate and intubation success. Ann Emerg Med 2024;84(1):1-8. doi:10.1016/j.annemergmed.2023.11.005.