hyomental distance ratio as a diagnostic predictor of difficult laryngoscopy in emergency...

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Background • Difficult visualization of the larynx (DVL) is a major cause of difficult intubation in many patients. • Recently, Takenaka et al. defined the ratio of the HMD in the neutral position and at the extreme of head extension as the hyomental distance ratio (HMDR) and demonstrated that it was a good predictor of a reduced occipitoatlantoaxial (OAA) complex extension capacity in patients with rheumatoid arthritis. • An assessment of the extension capacity of the OAA complex is an important component of preoperative tests for predicting DVL. • However, no study has quantified its diagnostic validity for predicting DVL. To determine usefulness of hyomental distance (HMD) ratio (HMDR) in predicting difficult laryngoscopy in Emergency department (ED) endotracheal intubation, by examining following airway predictors, the modified Cormack and Lehane scale and HMDR. Aims & Objectives Methods Conclusion Figure 1. Method for measuring the hyomental distance ratio (HMDR). HYOMENTAL DISTANCE RATIO AS A DIAGNOSTIC PREDICTOR OF DIFFICULT LARYNGOSCOPY IN EMERGENCY DEPARTMENT ENDOTRACHEAL INTUBATION. Dr. Maruteshwar Reddy; Dr. Nishanth Hiremath * ; Dr. Srihari Cattamanchi; Dr. T.V. Ramakrishnan. Sri Ramchandra Medical College & Research Institute, Porur, Chennai – 600116. Tamil Nadu. India. Results Dr. Maruteshwar Reddy; Mobile: +91-9962936505; Email id: [email protected] Study Design: A prospective observational study. Settings: Accident & Emergency Department of Sri Ramachandra Medical Centre, Chennai. Duration: One Month - January 2010. Inclusion Criteria: All non-traumatic patients registered in ED and undergoing endotracheal intubation at ED were included in the study. Exclusion Criteria: All trauma patients, gross anatomical abnormality, recent surgery of the head and neck, upper airway disease (e.g., maxillofacial fracture or tumors), loose teeth, or those requiring a rapid sequence or awake intubation were excluded from the study. Methodology: HMDR is defined as ratio of HMD at extreme of head extension to that in neutral position. • ED physician performing endotracheal intubation graded views using modified Cormack and Lehane scale and were blinded to results of airway evaluation. • Difficult Visualization of Larynx (DVL) was defined as Grade 3 or 4 views. Sampling Technique: Convinient sampling technique employed. Instrument used: A proforma was used. Statistical analysis: performed using SPSS ver.15.0. •A total of 26 patients were included in study, with 15 males (57.6%) and mean age of 43.96. •Mean height was 171.34 cms, mean weight was 75.84 kgs and mean BMI was 26.23. •Mean HMD was 7.23 with SD of 2.121 and range of 6 to 9. •Mean HMD with extreme extension of head was 8.60 with SD of 2.828 and range of 7 to 11. •Mean HMDR was 1.184 with SD of 0.183 and range of 1.07 to 1.33. •Mean modified Cormack and Lehane scale was 2.0 with SD of 2.121 and range of 1 to 4. •Larynx was difficult to visualize in 10 (38.46%) patients. •No failed intubations observed in the study. •HDMR was 83.3% sensitive, 100% specific, positive predictive value of 100% and negative predictive value of 87.5%. In conclusion, we demonstrated that HMDR is highly sensitive and specific and clinically is a reliable predictor of difficult visualization of larynx in an ED & that value of 1.2 can be used as test threshold.

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Page 1: HYOMENTAL DISTANCE RATIO AS A DIAGNOSTIC PREDICTOR  OF DIFFICULT LARYNGOSCOPY IN EMERGENCY DEPARTMENT  ENDOTRACHEAL INTUBATION

Background• Difficult visualization of the larynx

(DVL) is a major cause of difficult intubation in many patients.

• Recently, Takenaka et al. defined the ratio of the HMD in the neutral position and at the extreme of head extension as the hyomental distance ratio (HMDR) and demonstrated that it was a good predictor of a reduced occipitoatlantoaxial (OAA) complex extension capacity in patients with rheumatoid arthritis.

• An assessment of the extension capacity of the OAA complex is an important component of preoperative tests for predicting DVL.

• However, no study has quantified its diagnostic validity for predicting DVL.

To determine usefulness of hyomental distance (HMD) ratio (HMDR) in predicting difficult laryngoscopy in Emergency department (ED) endotracheal intubation, by examining following airway predictors, the modified Cormack and Lehane scale and HMDR.

Aims & Objectives

Methods Conclusion

Figure 1. Method for measuring the hyomental distance ratio (HMDR).

HYOMENTAL DISTANCE RATIO AS A DIAGNOSTIC PREDICTOR OF DIFFICULT LARYNGOSCOPY IN EMERGENCY DEPARTMENT

ENDOTRACHEAL INTUBATION. Dr. Maruteshwar Reddy; Dr. Nishanth Hiremath*; Dr. Srihari Cattamanchi;

Dr. T.V. Ramakrishnan.Sri Ramchandra Medical College & Research Institute, Porur, Chennai – 600116. Tamil Nadu. India.

Results

Dr. Maruteshwar Reddy; Mobile: +91-9962936505; Email id: [email protected]

Study Design: A prospective observational study. Settings: Accident & Emergency Department of Sri Ramachandra Medical Centre, Chennai. Duration: One Month - January 2010. Inclusion Criteria: All non-traumatic patients registered in ED and undergoing endotracheal intubation at ED were included in the study.

Exclusion Criteria: All trauma patients, gross anatomical abnormality, recent surgery of the head and neck, upper airway disease (e.g., maxillofacial fracture or tumors), loose teeth, or those requiring a rapid sequence or awake intubation were excluded from the study.

Methodology: HMDR is defined as ratio of HMD at extreme of head extension to that in neutral position.

• ED physician performing endotracheal intubation graded views using modified Cormack and Lehane scale and were blinded to results of airway evaluation.

• Difficult Visualization of Larynx (DVL) was defined as Grade 3 or 4 views.

Sampling Technique: Convinient sampling technique employed.

Instrument used: A proforma was used.

Statistical analysis: performed using SPSS ver.15.0.

•A total of 26 patients were included in study, with 15 males (57.6%) and mean age of 43.96.

•Mean height was 171.34 cms, mean weight was 75.84 kgs and mean BMI was 26.23.

•Mean HMD was 7.23 with SD of 2.121 and range of 6 to 9.

•Mean HMD with extreme extension of head was 8.60 with SD of 2.828 and range of 7 to 11.

•Mean HMDR was 1.184 with SD of 0.183 and range of 1.07 to 1.33.

•Mean modified Cormack and Lehane scale was 2.0 with SD of 2.121 and range of 1 to 4.

•Larynx was difficult to visualize in 10 (38.46%) patients.

•No failed intubations observed in the study.

•HDMR was 83.3% sensitive, 100% specific, positive predictive value of 100% and negative predictive value of 87.5%.

In conclusion, we demonstrated that HMDR is highly sensitive and specific and clinically is a reliable predictor of difficult visualization of larynx in an ED & that value of 1.2 can be used as test threshold.