Skip Navigation LinksHome > July 2004 - Volume 101 - Issue 1 > Grading Scale for Mask Ventilation
Anesthesiology:
Correspondence

Grading Scale for Mask Ventilation

Han, Richard M.D.; Tremper, Kevin K. Ph.D., M.D.*; Kheterpal, Sachin M.D.; O’Reilly, Michael M.S., M.D.

Free Access
Article Outline
Collapse Box

Author Information

Back to Top | Article Outline

To the Editor:—

One of the most important aspects of airway management is the ability to mask ventilate a patient. Although there are methods to assess the probability of the difficulty of intubation and grading the view during laryngoscopy, there is, to our knowledge, no recognized scale to grade mask ventilation.1–4
Langeron et al.5 investigated factors predictive of difficult mask ventilation. They found that the incident of difficult mask ventilation was 5% of all cases and was associated with five criteria: age older than 55 yr, body mass index greater than 26 kg/m2, lack of teeth, presence of a beard, or history of snoring. In this study, they rated mask ventilation as difficult when the clinician considered it “clinically relevant and could have led to potential problems if mask ventilation had to be maintained for a longer time.”5 They rated mask ventilation as impossible “when it completely failed and an alternative technique of ventilation was required in emergency conditions.”5 This study did not define a grading scale other than “difficult” and “impossible.”5 In an accompanying editorial, Adnet6 did recommend that a grading scale be developed. The American Society of Anesthesiologists Guidelines for Management of the Difficult Airway defines difficult facemask ventilation as the situation in which “it is not possible for the anesthesiologist to provide adequate face mask ventilation due to one or more of the following problems: inadequate mask seal, excessive gas leak, or excessive resistance to ingress or egress of gas.”7 The guidelines also describes the signs of an inadequate facemask ventilation, but again, there is no proposed grading system for the ability to facemask ventilate.7
Table 1
Table 1
Image Tools
Table 2
Table 2
Image Tools
During the development of a perioperative information system, we found it useful to devise a grading system similar to that used for grading the view during laryngoscopy. Initially, we chose grades 0–4, defined in table 1. There was also a means by which practitioners could type in a text description of mask ventilation. The incidence of each grade of ease or difficulty with mask ventilation is described in table 1. Institutional review board approval was received for this electronic chart review process. After approximately 3 weeks, we compiled the results of documentation using the selections chosen (table 1). On review of these data, we revised the definitions of the grading as described in table 2, removing the modifiers of “easy” and “difficult” before grades 1 and 2. After another 3 weeks, these data were again compiled with the results in table 2. The second version of the grading system resulted in similar percentages for both grade 3 and grade 4, a reduction in grade 1, and an increase in grade 2 classifications. We also noted a substantial decrease in the number of comments going from 1.4% to 0.3% of cases. We believed that the reduction in comments implied that the second method of defining the grades of mask ventilation was easier to select for the practitioners, although it may have been because individuals were more used to the system, in general. As with the grading of airway evaluation and view of laryngoscopy, grading the ability to mask ventilate is subjective and practitioner dependent. It is interesting to note that Langeron et al.5 reported one case of impossible to ventilate out of the 1,502 patients, whereas we noted three in 2,621 cases. This close agreement in the incidence of being unable to ventilate was probably because being unable to ventilate a patient is a more objective (and memorable) event. We did not find as close an agreement in patients who were defined as “difficult mask ventilation” (grade 3). Langeron et al.5 found this in 5% of their patients, whereas we noted an incidence of 1.3%. This may be because Langeron et al. had a broader definition of difficult mask ventilation. Ultimately, the most important grades to document are the more difficult ones, grades 3 and 4, because those would most likely affect the plan for future anesthetics. We have continued with the classifications and descriptions presented in table 2 and have found this information useful for planning future anesthetics, especially for patients in whom intubation was difficult.
Richard Han, M.D.
Kevin K. Tremper, Ph.D., M.D.,*
Sachin Kheterpal, M.D.
Michael O’Reilly, M.S., M.D.
* University of Michigan, Ann Arbor, Michigan. ktremper@umich.edu
Back to Top | Article Outline

References

1. Mallampati SR, Gatt SP, Gugino LD, Desai SP, Waraksa B, Dubravka F, Liu P: A clinical sign to predict difficult tracheal intubation: A prospective study. Can J Anaesth 1985; 32:429–34

2. Frerk CM: Predicting difficult intubation. Anaesthesia 1991; 46:1005–8

3. Tse JC, Rimm EB, Hussain A: Predicting difficult endotracheal intubation in surgical patients scheduled for general anesthesia: A prospective blind study. Anesth Analg 1995; 81:254–8

4. Cormack RS, Lehane J: Difficult tracheal intubation in obstetrics. Anesthesia 1984; 39:1005–111

5. Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, Coriat P, Riou B: Prediction of difficult mask ventilation. Anesthesiology 2000; 92:1229–36

6. Adnet F: Difficult mask ventilation. Anesthesiology 2000; 92:1217–8

7. Caplan RA, Benumof JL, Berry FA, Blitt CD, Bode RH, Cheney FW, Connis RT, Guidry OR, Ovassapian A: Practice Guidelines for Management of the Difficult Airway: A report by the ASA Task Force on Management of the Difficult Airway. Anesthesiology 1993; 78:597–602

Cited By:

This article has been cited 16 time(s).

Anaesthesia and Intensive Care
How do anaesthetists in New Zealand disseminate critical airway information?
Baker, PA; Moore, CL; Hopley, L; Herzer, KR; Mark, LJ
Anaesthesia and Intensive Care, 41(3): 334-341.

British Journal of Anaesthesia
Complications and failure of airway management
Cook, TM; MacDougall-Davis, SR
British Journal of Anaesthesia, 109(): I68-I85.
10.1093/bja/aes393
CrossRef
Anaesthesia
A complication of transtracheal jet ventilation and use of the Aintree intubation catheter (R) during airway resuscitation
Cook, TM; Bigwood, B; Cranshaw, J
Anaesthesia, 61(7): 692-697.
10.1111/j.1365-2044.2006.04686.x
CrossRef
Anaesthesia
Improvement in laryngoscopy grade with dramatic weight loss
Ross, AK; Jefferson, P; Ball, DR
Anaesthesia, 63(9): 1022.

Anaesthesia
Non-conventional uses of the Aintree Intubating Catheter in management of the difficult airway
Cook, TM; Seller, C; Gupta, K; Thornton, M; O'Sullivan, E
Anaesthesia, 62(2): 169-174.
10.1111/j.1365-2044.2006.04909.x
CrossRef
Anesthesia and Analgesia
Difficult Mask Ventilation
El-Orbany, M; Woehlck, HJ
Anesthesia and Analgesia, 109(6): 1870-1880.
10.1213/ANE.0b013e3181b5881c
CrossRef
Anaesthesia
Use of an i-gel (TM) for airway rescue
Joshi, NA; Baird, M; Cook, TM
Anaesthesia, 63(9): 1020-1021.

International Journal of Pediatric Otorhinolaryngology
Obesity and risk of peri-operative complications in children presenting for adenotonsillectomy
Nafiu, OO; Green, GE; Walton, S; Morris, M; Reddy, S; Tremper, KK
International Journal of Pediatric Otorhinolaryngology, 73(1): 89-95.
10.1016/j.ijporl.2008.09.027
CrossRef
British Journal of Anaesthesia
Use of a ProSeal(TM) laryngeal mask airway and a Ravussin cricothyroidotomy needle in the management of laryngeal and subglottic stenosis causing upper airway obstruction
Cook, TM; Asif, M; Sim, R; Waldron, J
British Journal of Anaesthesia, 95(4): 554-557.
10.1093/bja/aei201
CrossRef
Obesity Surgery
LMA Supreme (TM) Versus Facemask Ventilation Performed by Novices: A Comparative Study in Morbidly Obese Patients Showing Difficult Ventilation Predictors
Abdi, W; Dhonneur, G; Amathieu, R; Adhoum, A; Kamoun, W; Slavov, V; Barrat, C; Combes, X
Obesity Surgery, 19(): 1624-1630.
10.1007/s11695-009-9953-0
CrossRef
Anesthesia and Analgesia
A Novel Classification Instrument for Intraoperative Awareness Events
Mashour, GA; Esaki, RK; Tremper, KK; Glick, DB; O'Connor, M; Avidan, MS
Anesthesia and Analgesia, 110(3): 813-815.
10.1213/ANE.0b013e3181b6267d
CrossRef
Journal of Neurosurgical Anesthesiology
Predictors of Difficult Intubation in Patients With Cervical Spine Limitations
Mashour, GA; Stallmer, ML; Kheterpal, S; Shanks, A
Journal of Neurosurgical Anesthesiology, 20(2): 110-115.
10.1097/ANA.0b013e318166dd00
PDF (115) | CrossRef
Anesthesiology
Incidence and Predictors of Difficult and Impossible Mask Ventilation
Kheterpal, S; Han, R; Tremper, KK; Shanks, A; Tait, AR; O’Reilly, M; Ludwig, TA
Anesthesiology, 105(5): 885-891.

PDF (371)
Anesthesiology
Incidence and Risk Factors for Perioperative Adverse Respiratory Events in Children Who Are Obese
Tait, AR; Voepel-Lewis, T; Burke, C; Kostrzewa, A; Lewis, I
Anesthesiology, 108(3): 375-380.
10.1097/ALN.0b013e318164ca9b
PDF (208) | CrossRef
Anesthesiology
Prediction and Outcomes of Impossible Mask Ventilation: A Review of 50,000 Anesthetics
Kheterpal, S; Martin, L; Shanks, AM; Tremper, KK
Anesthesiology, 110(4): 891-897.
10.1097/ALN.0b013e31819b5b87
PDF (316) | CrossRef
Anesthesiology
Face Mask Ventilation in Edentulous Patients: A Comparison of Mandibular Groove and Lower Lip Placement
Racine, S; Solis, A; Hamou, N; Letoumelin, P; Hepner, D; Beloucif, S; Baillard, C
Anesthesiology, 112(5): 1190-1193.
10.1097/ALN.0b013e3181d5dfea
PDF (376) | CrossRef
Back to Top | Article Outline

© 2004 American Society of Anesthesiologists, Inc.

Publication of an advertisement in Anesthesiology Online does not constitute endorsement by the American Society of Anesthesiologists, Inc. or Lippincott Williams & Wilkins, Inc. of the product or service being advertised.
Login

Article Tools

Images

Share