Modified-ramped position versus ramped position for time to intubation in obese patients undergoing general anesthesia
Keywords:
obesity, tracheal intubation, ramped position, modified-ramped positionAbstract
Obese patients are at high risk for complications during tracheal intubation due to altered anatomy. Proper positioning is therefore crucial for successful and safe intubation. This study aimed to compare the effectiveness of the modified ramped position versus the ramped position for tracheal intubation in obese patients. This was a quasi experimental study involving 80 obese patients (BMI ≥30 kg/m2) scheduled for elective surgery under general anesthesia at Chaiyaphum Hospital between November 2024 and March 2025. Patients were randomly allocated into the modified ramped position group and the ramped position group (40 patients per group). The primary outcome was the intubation time. Data were analyzed using the Mann-Whitney U test, Chi-square test, Fisher's exact test and Quantile regression.
The median intubation time was 29.0 seconds (IQR: 25.0–34.3) in the Modified Ramped position group and 30.0 seconds (IQR: 23.0–35.3) in the Ramped position group, showing no significant difference (p-value = 0.851). Secondary outcomes (mask ventilation, Good laryngeal view, First attempt success, Complications) were all similar between the two groups. However, a quantile regression analysis, adjusted for the Mallampati score, revealed that in patients with high difficulty (Q90), the Modified Ramped position significantly increased the intubation time by 3.8 seconds (95% CI: 0.5, 7.1) compared to the Ramped position (p-value = 0.024). No difference was found in patients with easy to moderate intubation difficulty (Q25–Q75).
Both the modified ramped position and the ramped position demonstrated similar overall effectiveness in obese patients. However, the choice of position should consider the specific characteristics of individual patients, especially the pre-operative assessment of intubation difficulty. In patients anticipated to have high difficulty, the traditional Ramped position may be more suitable than the modified ramped position.
References
Langeron O, Birenbaum A, Le Saché F, Raux M. Airway management in obese patient. Minerva Anestesiol 2014;80(3):382–92. https://www.minervamedica.it/en/ journals/minerva-anestesiologica/ article.php?cod=R02Y2014N03A0382
De Jong A, Molinari N, Pouzeratte Y, Verzilli D, Chanques G, Jung B, et al. Difficult intubation in obese patients: incidence, risk factors, and complications in the operating theatre and in intensive care units. Br J Anaesth 2015;114(2):297–306. DOI:10.1093/bja/aeu373
Ogunnaike BO, Jones SB, Jones DB, Provost D, Whitten CW. Anesthetic considerations for bariatric surgery. Anesth Analg 2002;95(6):1793-805. DOI:10.1097/00000539-200212000-00061
Ezri T, Medalion B, Weisenberg M, Szmuk P, Warters RD, Charuzi I. Increased body mass index per se is not a predictor of difficult laryngoscopy. Can J Anaesth 2003;50(2):179-83. DOI:10.1007/BF03017853
เสาวภา ไพศาลพันธุ์. การพัฒนารูปแบบการดูแลผู้ป่วยหลังได้รับยาระงับความรู้สึกในห้องพักฟื้น กลุ่มงานการพยาบาลวิสัญญี โรงพยาบาลชัยภูมิ. ชัยภูมิเวชสาร 2560;37(2):49-58. https://thaidj.org/ index.php/CMJ/article/view/7339
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC, Ortega R, et al. [editor]. Clinical anesthesia. 8th ed. Philadelphia, PA : Wolters Kluwer, 2017.
Park SH, Park HP, Joen YT, Hwang JW, Kim JH, Bahk JH. A comparison of direct laryngoscopic views depending on pillow height. J Anesth 2010;24(4):526-30. DOI:10.1007/s00540-010-0962-x
Rao SL, Kunselman AR, Schuler HG, DesHarnais S. Laryngoscopy and tracheal intubation in the head-elevated position in obese patients: a randomized, controlled, Equivalence Trial. Anesth Analg 2008;107(6):1912–8. DOI:10.1213/ane.0b013e31818556ed
Greenland KB, Edwards MJ, Hutton NJ. External auditory meatus-sternal notch relationship in adults in the sniffing position: a magnetic resonance imaging study. Br J Anaesth 2010;104(2):268–9. DOI:10.1093/bja/aep390
Hasanin A, Tarek H, Mostafa MMA, Arafa A, Safina AG, Elsherbiny MH, et al. Modified-ramped position: a new position for intubation of obese females: a randomized controlled pilot study. BMC Anesthesiol 2020;20(1):151. DOI:10.1186/s12871-020-01070-2
Alimian M, Zaman B, Seyed Siamdoust SA, Nikoubakht N, Rounasi R. Comparison of RAMP and new modified RAMP positioning in laryngoscopic view during intubation in patients with morbid obesity: a randomized clinical trial. Anesthesiol Pain Med 2021;11(3):e114508. DOI:10.5812/aapm.114508
Kim H, Chang JE, Won D, Lee JM, Kim TK, Kim MJ, et al. Effect of head and neck positions on tracheal intubation using a McGRATH MAC video laryngoscope: A randomised, prospective study. Eur J Anaesthesiol 2023;40(8):560-7. DOI:10.1097/EJA.0000000000001838
Krage R, van Rijn C, van Groeningen D, Loer SA, Schwarte LA, Schober P. Cormack-Lehane classification revisited. Br J Anaesth 2010;105(2):220-7. DOI:10.1093/bja/aeq136
Dixon BJ, Dixon JB, Carden JR. Burn AJ, Schachter LM, Playfair JM, et al. Preoxygenation is more effective in the 25 degrees head-up position than in the supine position in severely obese patients: a randomized controlled study. Anesthesiology 2005;102(6): 1110-5. DOI:10.1097/00000542-200506000-00009
Bohringer C, Duca J, Liu H. A Synopsis of Contemporary Anesthesia Airway Management. Transl Perioper Pain Med 2019;6(1):5-16. PMCID:PMC6785195
Lee JH, Jung HC, Shim JH, Lee C. Comparison of the rate of successful endotracheal intubation between the "sniffing" and "ramped" positions in patients with an expected difficult intubation: a prospective randomized study. Korean J Anesthesiol 2015;68(2):116–21. DOI:10.4097/kjae.2015.68.2.116
Semler MW, Janz DR, Lentz RJ, Matthews DT, Norman BC, Assad TR, et al. Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill. Am J Respir Crit Care Med 2016;193(3):273-80. DOI:10.1164/rccm.201507-1294OC
Goh ZJ, Ang A, Ang SN, See S, Zhang J, Venkatesan K, et al. Videolaryngoscopy vs. direct laryngoscopy in class 2 and 3 obesity: a systematic review, meta-analysis and trial sequential analysis of randomised controlled trials. Anaesthesia 2025;80(6):684-93. DOI:10.1111/anae.16578
Collins JS, Lemmens HJ, Brodsky JB, Brock-Utne JG, Levitan RM. Laryngoscopy and morbid obesity: a comparison of the "sniff" and "ramped" positions. Obes Surg 2004;14(9):1171–5. DOI:10.1381/0960892042386869
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