A comparison of the Extended Mallampati Score with the ratio of patient's height to thyromental distance, the modified Mallampati and the upper lip bite test in predicting difficulty in endotracheal intubation in patients undergoing general enesthesia
Background and objective: Preoperative using of anatomical landmarks detects potentially difficult laryngoscopies. The main object of the present study was to evaluate the predictive power of Extended Mallampati Score in comparison with modified Mallampati test , the ratio of height to thyromental distance and the Upper-Lip-Bite test in isolation and combination.
Material and Methods: Four hundred seventy six adult patients who candidate for elective surgery under general anesthesia requiring endotracheal intubation were included in this study and evaluated based of all four factors before surgery. After that, laryngoscopy was performed by an anesthesiologist who didn’t involve in preoperative airway assessment and garaded based on Cormack and Lehane’s classification. We calculated sensitivity, specificity, and area under receiver-operating characteristic (ROC) (AUC) for each score.
Results: The AUC of the ROC was significantly more for the ULBT (AUC = 0.820, P = 0.049) and RHTMD score (AUC = 0.845, P = 0.033) than the EMS (AUC = 0.703). This variable was significantly higher for the EMS compared with MMT (0.703 vs. 0.569, P = 0.046 respectively). There was no significant difference between the AUC of the ROC for the ULBT and the RHTMD score (P = 0.685). The optimal cut-off point for the RHTMD for predicting difficult laryngoscopy was 29.3.
Conclusion: EMS predicted difficult laryngoscopy better than MMT while both ULBT and RHTMD had more power than EMS and MMT in this regard. ULBT and RHTMD had similar predictive value for prediction of difficult laryngoscopy in general population.
Keywords: Extended Mallampati Score, ratio of patient's height to thyromental distance, modified Mallampati, upper lip bite test, difficult laryngoscopy
General information
Acronym
IRCT registration information
IRCT registration number:IRCT201102185362N2
Registration date:2012-11-15, 1391/08/25
Registration timing:retrospective
Last update:
Update count:0
Registration date
2012-11-15, 1391/08/25
Registrant information
Name
Mohammadreza Safavi
Name of organization / entity
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan
Country
Iran (Islamic Republic of)
Phone
+98 31 1273 2659
Email address
safavi@med.mui.ac.ir
Recruitment status
Recruitment complete
Funding source
Isfahan University of Medical Sciences
Expected recruitment start date
2011-03-21, 1390/01/01
Expected recruitment end date
2012-03-20, 1391/01/01
Actual recruitment start date
empty
Actual recruitment end date
empty
Trial completion date
empty
Scientific title
A comparison of the Extended Mallampati Score with the ratio of patient's height to thyromental distance, the modified Mallampati and the upper lip bite test in predicting difficulty in endotracheal intubation in patients undergoing general enesthesia
Public title
A comparison of the Extended Mallampati Score with the ratio of patient's height to thyromental distance, the modified Mallampati and the upper lip bite test in predicting difficulty in endotracheal intubation in patients undergoing general enesthesia
Purpose
Prevention
Inclusion/Exclusion criteria
inclusion crateris : patients who had no previous history of burn or trauma to the airway؛ had no tumors or mass in the laryngeal؛ facial and cervical region؛ had no restricted mobility of the neck and mandible (e.g., rheumatoid arthritis or cervical disk disorders)؛ had ability to sit and open their mouth.
Age
No age limit
Gender
Both
Phase
N/A
Groups that have been masked
No information
Sample size
Target sample size:
476
Randomization (investigator's opinion)
N/A
Randomization description
Blinding (investigator's opinion)
Double blinded
Blinding description
Placebo
Not used
Assignment
Single
Other design features
Secondary Ids
empty
Ethics committees
1
Ethics committee
Name of ethics committee
Isfahan University of Medical Sciences, Isfahan, Iran
Street address
Isfahan University of Medical Sciences, Isfahan, Iran
City
Isfahan
Postal code
8174675731
Approval date
2011-01-30, 1389/11/10
Ethics committee reference number
390341
Health conditions studied
1
Description of health condition studied
intubation
ICD-10 code
T88.4
ICD-10 code description
Intubation, difficult or failed
Primary outcomes
1
Description
ELV
Timepoint
before intubation
Method of measurement
physical exam
2
Description
DLV
Timepoint
before intubation
Method of measurement
physical exam
Secondary outcomes
1
Description
reduce mortality
Timepoint
after intubation
Method of measurement
physical exam
Intervention groups
1
Description
different methods for measuring ELV and DLV
Category
Prevention
Recruitment centers
1
Recruitment center
Name of recruitment center
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, I
Full name of responsible person
Mohammadreza Safavi
Street address
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, I
City
Isfahan
Sponsors / Funding sources
1
Sponsor
Name of organization / entity
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, I
Full name of responsible person
Azim Honarmand
Street address
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, I
City
Isfahan
Grant name
Grant code / Reference number
Is the source of funding the same sponsor organization/entity?
Yes
Title of funding source
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, I
Proportion provided by this source
100
Public or private sector
empty
Domestic or foreign origin
empty
Category of foreign source of funding
empty
Country of origin
Type of organization providing the funding
empty
Person responsible for general inquiries
Contact
Name of organization / entity
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, I
Full name of responsible person
Mohammadreza Safavi
Position
Associate Professor of Anesthesia
Other areas of specialty/work
Street address
Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
City
Isfahan
Postal code
8174675731
Phone
+98 31162555555
Fax
+98 31 1668 4510
Email
safavi@med.mui.ac.ir
Web page address
www.mui.ac.ir
Person responsible for scientific inquiries
Contact
Name of organization / entity
Anesthesiology and Critical Care Research Center,Isfahan University of Medical Sciences, Isfahan, Ir
Full name of responsible person
Azim Honarmand
Position
Associate Professor of Anesthesia
Other areas of specialty/work
Street address
Anesthesiology and Critical Care Research Center,Isfahan University of Medical Sciences, Isfahan, Iran
City
Isfahan
Postal code
8174675731
Phone
+98 31 1273 2659
Fax
Email
honarmand@med.mui.ac.ir
Web page address
www.mui.ac.ir
Person responsible for updating data
Contact
Name of organization / entity
Anesthesiology and Critical Care Research Center,Isfahan University of Medical Sciences, Isfahan, Ir
Full name of responsible person
Mohammadreza Safavi
Position
Associate Professor of Anesthesia
Other areas of specialty/work
Street address
Anesthesiology and Critical Care Research Center,Isfahan University of Medical Sciences, Isfahan, Iran
City
Isfahan
Postal code
8174675731
Phone
+98 31 1625 5555
Fax
+98 31 1668 4510
Email
safavi@med.mui.ac.ir
Web page address
www.mui.ac.ir
Sharing plan
Deidentified Individual Participant Data Set (IPD)