Details
Category: Volume 07 Issue 07 July 2019
Hits: 1012

Title: Incidence of Difficult Intubation in Obese & Non-Obese Patients Using Intubation Difficulty Scale

Authors: Dr Roshna C P, Dr Ajith Kumar .G, Dr Sheela Varghese

 DOI: https://dx.doi.org/10.18535/jmscr/v7i7.121

Abstract

Introduction: Unanticipated difficult intubation is challenging to anaesthesiologists. The global epidemic of overweight and obesity is rapidly becoming a major health problem and anaesthetists frequently encounter such patients whose airway management is their major responsibility. Intubation Difficulty Scale (IDS) had been used as a validated difficulty score to define difficult intubation. In this study, we intend to find out the incidence of difficult intubation in obese and non-obese patients using Intubation Difficulty Scale.

Objectives: The primary objective of the study is to assess the incidence of Intubation Difficulty Scale (IDS) score ≥ 5 in obese and non-obese patients. The secondary objective is to assess the performance of Modified Mallampati Classification, Mouth opening, Thyromental distance and Sternomental distance in predicting Intubation Difficulty Scale (IDS) score ≥5 in obese and non-obese patients.

Methods: This study is a prospective cohort study. The study population was from the Department of Anaesthesiology, Government Medical College, Thiruvananthapuram with ASA- physical status I & II patients in the age groups 18 to 60 years, scheduled to undergo surgery requiring General Anaesthesia with controlled ventilation using an Endotracheal tube. After obtaining informed written consent and Institutional Research Committee and Ethical Committee clearance, 140 patients requiring General Anaesthesia were categorized into 70 each based on the Body Mass Index (BMI) into obese (BMI≥ 25kg/m2) and non- obese (BMI<25kg/m2)groups. Preoperative airway assessment included Modified Mallampati Classification, mouth opening, Thyromental distance and Sternomental distance. IDS score ≥ 5 was termed Difficult Intubation.

Data was entered in Microsoft Excel and data analyzed using SPSS software version 16. All the quantitative data were analyzed by computing percentages and descriptive statistics, ie: mean, standard deviation and standard error of mean and qualitative data by means of proportions. Suitable statistical tests were applied and results were considered statistically significant whenever p- value of ≤0.05 was obtained.

Results: Overall in 140 patients, the incidence of difficult intubation was found to be 16.4%. 27.1% of obese patients and 5.7% of non-obese patients had difficult intubation. Obese patients were more difficult to intubate than non- obese patients. Obstructive Sleep Apnea (OSA), Modified Mallampati Classification III/IV, Thyromental distance (TMD) < 6.5cms and Sternomental distance (SMD)< 12.5cms were found to be associated with IDS score ≥ 5. SMD <12.5cms was found to be the single best predictor of difficult intubation. IDS score is helpful in evaluating the predictive factors of difficult intubation.

Conclusions: Obese patients are more difficult to intubate than non-obese patients. It is preferable to have a second skilled Anaesthesiologist, during intubation of obese patients with OSA, MMC III/IV, TMD <6.5cms and SMD <12.5cms.

Keywords: Difficult intubation, intubation difficulty scale, obese, non-obese.

References

  1. F, Borron SW, Racine SX, Clemessy JL, Fournier JL, Plaisance P, et al. The Intubation Difficulty Scale(IDS): Proposal and evaluation of a new score characterizing the complexity of endotracheal intubation. Anaesthesiology. 1997;87:1290-7.
  2. Practice guidelines for management of difficult airway. A report by the American Society of Anaesthesiologists Task Force on management of the Difficult Airway. Anaesthesiology. 1993;78:597- 602.
  3. Benumof JL. Management of the difficult adult airway. With special emphasis on awake tracheal intubation. Anaesthesiology. 1991;75:1087-1 10.
  4. Lavi R, Segal D, Ziser A. Predicting difficult airways using the y Intubation Difficulty Scale: A study comparing obese and non-obese patients. J ClinAnesth. 2009;21:264-7.
  5. Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, C'oriat P, et al. Prediction of difficult mask ventilation. Anesthesiology. 2000;92:1229-36.
  6. Shiga T, Wajima Z, Inoue T, Sakamoto A. Predicting difficult intubation in apparently normal patients. A meta-analysis of bedside screening test performance. Anesthesiology. 2005;103: 429-37.
  7. Misra A, Chowbey P, Makkar BM, Vikram NK, Wair JS, Chdha D, et al. Consensus statement for diagnosis of obesity, abdominal obesity and metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management. J Assoc Physicians Indi. 2009;57:163-70.
  8. WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet. 2004;363:157-63.
  9. Juvin P, Lavaut E, Dupont H, Lefevre P, Demetriou M, Dumoulin JL, et al. Difficult tracheal intubation is more common in obese than in lean patients. Anesth Analg.2003;97:595-600
  10. Brodsky JB, LemmensHJ, Brock-Utne JG, Vierra M, Saidman LJ. Morbid obesity and tracheal intubation .Anesth Anal. 2002;94:732-6.

Corresponding Author

Dr Ajith Kumar .G

Associate Professor, Dept of Anaesthesiology, Govt. Medical College, Manjeri, India