D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
312
In e na ional Jou nal o Medical
and Pha maceu ical Resea ch
Online ISSN-2958-3683 | P in ISSN-2958-3675
F equency: Bi-Mon hly
A ailable online on: h ps://ijmp .in/
O iginal A icle
Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o
Di icul Visualiza ion o he La ynx: An Obse a ional S udy
D Ashley Elizabe h Thomas1, D Sonia M Lal2*, D Sandhya Sudhee 3, D Ushade i RS4
1 Junio esiden Depa men o Anaes hesiology, S ee Gokulam Medical College, and Resea ch Founda ion, T i and um, Ke ala,
India
2 Associa e P o esso , Depa men o Anaes hesiology, S ee Gokulam Medical College, and Resea ch Founda ion, T i and um,
Ke ala, India
3 Specialis Anaes he is , Depa men o Anaes hesiology, NMC Special y Hospi al, AlNahda, Dubai, Uni ed A ab Emi a es
4 P o esso and Head o he Depa men , Depa men o Anaes hesiology, S ee Gokulam Medical College, and Resea ch
Founda ion, T i and um, Ke ala, India
A B S T R A C T
Co esponding Au ho :
D Sonia M Lal
Associa e P o esso , Depa men
o Anaes hesiology, S ee Gokulam
Medical College, and Resea ch
Founda ion, T i and um, Ke ala,
India
Recei ed: 14-10-2025
Accep ed: 29-10-2025
A ailable online: 12-11-2025
Backg ound: Unexpec ed di icul y du ing in uba ion can lead o se ious
complica ions. The Ac omio–Axilla y–Sup as e nal No ch Index (AASI) has been
p oposed as a simple bedside es o p edic ing di icul isualiza ion o he la ynx
(DVL). This s udy e alua ed he diagnos ic accu acy o AASI compa ed wi h
con en ional p edic o s.
Me hodology: A p ospec i e obse a ional s udy was conduc ed in 131 adul
pa ien s (ASA I–II) unde going elec i e su ge y unde gene al anes hesia.
P eope a i e AASI was measu ed in he supine posi ion, and he Co mack–Lehane
(CL) g ade du ing di ec la yngoscopy was eco ded by an anes hesiologis blinded
o AASI alues. G ades I–IIa we e classi ied as easy isualiza ion (EVL) and g ades
IIb–IV as DVL. Recei e ope a ing cha ac e is ic (ROC) analysis de e mined he
op imal AASI cu o o p edic ing DVL.
Resul s: DVL occu ed in 33.6% (44/131) o pa ien s. Mean AASI was signi ican ly
highe in DVL cases (0.53 ± 0.08) han in EVL cases (0.38 ± 0.07; p < 0.001). ROC
analysis yielded an AUC o 0.86. The op imal AASI cu o alue (0.46) p edic ed
DVL wi h 72.7% sensi i i y, 87.4% speci ici y, a posi i e p edic i e alue o 74.4%,
and a nega i e p edic i e alue o 86.4%.
Conclusion: AASI is a simple, non-in asi e, and eliable bedside index o
p edic ing di icul la yngoscopy in supine pa ien s. I can complemen con en ional
assessmen s such as he Modi ied Mallampa i classi ica ion, especially when pa ien
coope a ion is limi ed. Fu he s udies wi h la ge popula ions a e wa an ed o
alida e i s ou ine use.
Copy igh © In e na ional Jou nal o
Medical and Pha maceu ical Resea ch
Keywo ds: Ac omio–Axilla y–Sup as e nal No ch Index, Ai way P edic o s ,
Di icul Ai way, La yngoscopy, Mallampa i Classi ica ion
INTRODUCTION
Unan icipa ed di icul y du ing endo acheal in uba ion emains a majo cause o anes hesia- ela ed mo bidi y and
mo ali y, wi h complica ions anging om hypoxia and a hy hmias o ca diac a es .[1,2] Accu a e p eope a i e p edic ion
o di icul isualiza ion o he la ynx (DVL) is he e o e essen ial o e ec i e ai way managemen and imp o ed pa ien
sa e y. Se e al bedside sc eening es s such as he Modi ied Mallampa i classi ica ion (MPC), hy omen al dis ance, and
s e nomen al dis ance ha e been adi ionally used o p edic di icul la yngoscopy. Howe e , hese es s o en show
limi ed sensi i i y and speci ici y and depend on pa ien coope a ion and p ope posi ioning, which may no always be
easible—pa icula ly in c i ically ill o supine pa ien s.[3–6] In 2013, Kam anmanesh e al. in oduced he Ac omio–
Axilla y–Sup as e nal No ch Index (AASI) as a no el, objec i e, and posi ion-independen p edic o o DVL.[7] AASI
measu es he ela i e dep h o he neck in o he ho ax and can be assessed easily in he supine posi ion. Ea ly s udies
epo ed high diagnos ic accu acy o AASI, bu e idence emains limi ed, especially among di e se popula ions.[8,9,10] The
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
313
p esen s udy was designed o e alua e he diagnos ic accu acy o AASI in p edic ing di icul isualiza ion o he la ynx
in adul pa ien s unde going elec i e su ge y unde gene al anes hesia. We aimed o de e mine he sensi i i y, speci ici y,
posi i e p edic i e alue (PPV), and nega i e p edic i e alue (NPV) o AASI and o compa e i s pe o mance wi h he
Modi ied Mallampa i classi ica ion.
Me hodology
S udy Design and Se ing
A p ospec i e obse a ional s udy was conduc ed in he Depa men o Anaes hesiology, in a supe speciali y medical
college hospi al om Sep embe 2022 o Sep embe 2023, a e ob aining Ins i u ional Resea ch commi ee (IRC No:
378/08/2022) and E hics Commi ee app o al (IEC No: 47/623/09/2022).
Pa icipan s
Adul pa ien s (18–70 yea s, ASA physical s a us I–II) scheduled o elec i e su ge ies unde gene al anes hesia wi h
endo acheal in uba ion we e included by consecu i e sampling. Pa ien s wi h head, neck, o ho acic de o mi ies; ce ical
spine abno mali ies; p io head and neck su ge y; his o y o di icul ai way; obesi y (BMI > 30 kg/m²); obs e ic cases; o
inabili y o open he mou h we e excluded.
Sample size
Consecu i e sampling was done- consecu i e cases mee ing he eligibili y c i e ia was included in he s udy. Sample size
was calcula ed using sensi i i y and speci ici y. Highes sample size was ound o be 131.
Measu emen o AASI
Wi h he pa ien in he supine posi ion and a ms es ing alongside he body, a e ical line (A) was d awn om he ac omion
p ocess o he uppe bo de o he axilla a he le el o he pec o alis majo . A pe pendicula line (B) was ex ended om
he sup as e nal no ch o in e sec line A. The segmen abo e he in e sec ion was designa ed as line C. The Ac omio–
Axilla y–Sup as e nal No ch Index (AASI) was calcula ed as C/A.
Fig 1: Measu emen o AASI
Ai way Assessmen and La yngoscopy
P eope a i e ai way assessmen included he Modi ied Mallampa i classi ica ion (MPC). Following induc ion o gene al
anes hesia wi h s anda d agen s, la yngoscopy was pe o med in he sni ing posi ion using a Macin osh blade by an
anes hesiologis blinded o he AASI alues. The la yngeal iew was g aded acco ding o he modi ied Co mack–Lehane
(CL) scale. G ades I–IIa we e classi ied as easy isualiza ion o he la ynx (EVL) and g ades IIb–IV as di icul
isualiza ion (DVL).
S a is ical Analysis
Da a we e analyzed using SPSS e sion 25. Recei e ope a ing cha ac e is ic (ROC) cu e analysis was used o de e mine
he diagnos ic accu acy o AASI and iden i y he op imal cu o alue o p edic ing DVL. Sensi i i y, speci ici y, posi i e
p edic i e alue (PPV), and nega i e p edic i e alue (NPV) we e calcula ed. A p- alue < 0.05 was conside ed s a is ically
signi ican .
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
314
Resul s
Age dis ibu ion
131 pa ien s we e en olled o his s udy whose age g oup anges om 21(minimum) o 70 (maximum) . Majo i y we e o
he age g oup 41-50 yea s (28.2%) and leas pa ien s om he age g oup 61- 70 yea s (9.9%). We no iced ha majo i y
pa ien s had EVL, bu in elde ly (61-70) and younge (21-30)g oups , EVL and DVL bo h had oughly he same p e alence.
Table 1: Age dis ibu ion
Age in yea s
F equency
Pe cen
21-30
21
16
31 – 40
27
20.6
41 – 50
37
28.2
51 – 60
33
25.2
61 – 70
13
9.9
To al
131
100
Fig 2: Age dis ibu ion
Fig 3: Age /s DVL , EVL
Table 2: Age /s DVL , EVL
Age
EVL
DVL
To al
χ2
d
p
N
%
N
%
N
%
21-30
11
12.6
10
22.7
21
16
31 - 40
21
24.1
6
13.6
27
20.6
41 - 50
26
29.9
11
25
37
28.2
0
5
10
15
20
25
30
21-30 31 - 40 41 - 50 51 - 60 61 - 70
Pe cen age
Age in yea s
Age dis ibu ion
Age in yea s
0
5
10
15
20
25
30
35
21-30 31 - 40 41 - 50 51 - 60 61 - 70
Pe cen age
Age in yea s
Age dis ibu ion
EVL
DVL
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
315
51 - 60
21
24.1
12
27.3
33
25.2
61 - 70
8
9.2
5
11.4
13
9.9
3.916
4
0.417
To al
87
100
44
100
131
100
Gende dis ibu ion
Ou o 131 pa ien s in o al, 63 (48.1% ) we e emales and 68 (51.9%) we e males. Ou s udy is consis en wi h o he
s udies which s a e ha he incidence o di icul ai way is mo e in males han in emales. In his s udy incidence o DVL
in males was 39% and in emales was 26%.
Table 3: Gende dis ibu ion
Gende
F equency
Pe cen
Female
63
48.1
Male
68
51.9
To al
131
100
Fig 4: Gende dis ibu ion
Table 4: Gende /s EVL, DVL
EVL
DVL
To al
χ2
d
p
Gende
N
%
N
%
N
%
Female
46
52.9
17
38.6
63
48.1
Male
41
47.1
27
61.4
68
51.9
2.373
1
0.123
To al
87
100
44
100
131
100
Female
48.1%
Male
51.9%
GENDER
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
316
Fig 5: Gende /s EVL, DVL
BMI Dis ibu ion
BMI o he pa ien s anged om 18 o 29.1. BMI > 30 we e no included in he s udy since obesi y in i sel is a p edic o
o di icul ai way. None o he pa ien s we e unde weigh ( BMI < 18). 86 pa ien s(65% ) we e ound o ha e no mal
weigh . 45 pa ien s (34%) we e o e weigh . We s udied BMI in hese pa ien s and do no see much inc ease in DVL wi h
inc ease in BMI. This is p obably because he e ec s o BMI on DVL is mo e appa en in he Obese ( BMI >30)
Table 5: BMI dis ibu ion
BMI
F equency
Pe cen
No mal
86
65.6
O e weigh
45
34.4
To al
131
100
Table 6: BMI /s DVL. EVL
EVL
DVL
To al
χ2
d
P
BMI
N
%
N
%
N
%
No mal
57
65.5
29
65.9
86
65.6
O e weigh
30
34.5
15
34.1
45
34.4
.002
1
0.964
To al
87
100
44
100
131
100
Fig 6: BMI dis ibu ion
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
EVL DVL
Gende
Male
Female
No mal
65.6%
O e weigh
34.4%
BMI
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
317
Fig 7: BMI /s DVL. EVL
ASA s a us dis ibu ion
ASA physical s a us I and II we e included in he s udy. 48 pa ien s we e ASA I (36.6%) and 83 pa ien s we e ASA II
(63.4%). We do no see any e iden co- ela ion be ween ASA physical s a us and DVL,
37.5 % o ASA I had DVL while 31.3 % o ASA II pa ien s had DVL.
Table 7: ASA dis ibu ion
ASA
F equency
Pe cen
1
48
36.6
2
83
63.4
To al
131
100
Fig 8: ASA dis ibu ion
Table 8: ASA /s DVL, EVL
EVL
DVL
To al
χ2
d
P
ASA
N
%
N
%
N
%
1
30
34.5
18
40.9
48
36.6
2
57
65.5
26
59.1
83
63.4
.520
1
0.471
To al
87
100
44
100
131
100
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
EVL DVL
BMI
O e weigh
No mal
G ade I
36.6%
G ade II
63.4%
ASA
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
318
Fig 9 : ASA /s DVL, EVL
Mallampa i class dis ibu ion
Modi ied Mallampa i classi ica ion e ealed classes I,II,III and IV among he pa ien s. 37 pa ien s (28.2%) we e class I,
65 (49.6%) we e class II, 28 (21.4%) we e class III and 1 pa ien was class IV. As expec ed MMC class I and II had high
ac ion o EVL .Howe e only one pa ien was ound o ha e MMC class IV .Howe e a signi ican ac ion o MMC I
and II we e ound o ha e DVL
Table 9: MMC dis ibu ion
MMC
F equency
Pe cen
1
37
28.2
2
65
49.6
3
28
21.4
4
1
0.8
To al
131
100
Fig 10: MMC dis ibu ion
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
EVL DVL
ASA
G ade II
G ade I
0
10
20
30
40
50
60
G ade I G ade II G ade III G ade IV
Pe cen age
MMC
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
319
Table 10: MMC /s DVL, EVL
EVL
DVL
To al
χ2
d
p
MMC
N
%
N
%
N
%
1
23
26.4
14
31.8
37
28.2
2
46
52.9
19
43.2
65
49.6
3
17
19.5
11
25
28
21.4
1.766
3
0.622
4
1
1.1
0
0
1
0.8
To al
87
100
44
100
131
100
Fig 11: MMC /s DVL, EVL
CL G ade dis ibu ion
Co mack Lehane g ading on di ec la yngoscopy was eco ded as g ade I, IIA,IIB, IIIA,IIIB and IV. 54 pa ien s(41.2%)
had g ade I, 33 pa ien s (25.2%) had g ade II A, 14 pa ien s (10.7%) had g ade IIB, 19 pa ien s (14.5 %) had g ade IIIA
and 6 pa ien s (4.6%) had IIIB and 5 pa ien s (3.8%) had g ade IV. We see a s eady decline in equency o pa ien s a
highe CL g ades. The main ocus o his s udy is o es ablish he co- ela ion be ween Line C/A and CL g ading. We
calcula e he a e age line C o each g ade o CL. We see a clea co ela ion be ween CL g ade and Line C. We see ha he
mean o Line C inc eases wi h he CL g ade, s a ing wi h G ade II B, which is he g ade whe e di icul ai way s a s. The
di e ence be ween he mean line C o each g ade and he p e ious g ade, is signi ican compa ed o he s anda d de ia ion
o he line C alues. The AASI alue inc eases s eadily wi h inc ease in CL g ade. Due o he posi i e co ela ion be ween
he AASI alue and he CL g ade, he AASI alue can be used o p edic di icul y in ai way in pa ien s. Pa ien s wi h AASI
g ea e han 0.469 a e classi ied as di icul ai way pa ien s, whe eas hose wi h AASI lesse han 0.469 a e classi ied as
easy ai way pa ien s. This is because an AASI alue o 0.469 co esponds o a CL g ade o II B, which is he onse o
di icul y in ai way, as pe li e a u e.
Table 11: CL g ade dis ibu ion
CL GRADE
F equency
Pe cen
G ade I
54
41.2
G ade II A
33
25.2
G ade II B
14
10.7
G ade III A
19
14.5
G ade III B
6
4.6
G ade IV
5
3.8
To al
131
100
0
10
20
30
40
50
60
G ade I G ade II G ade III G ade IV
Pe cen age
MMC
MMC
EVL
DVL
D Ashley Elizabe h Thomas e al. Ac omio–Axilla y–Sup as e nal No ch Index (AASI) as a P edic o o Di icul
Visualiza ion o he La ynx: An Obse a ional S udy. In . J Med. Pha m. Res., 6 (6): 312‐324, 2025
320
Fig 12: CL g ade dis ibu ion
Table 12: CL g ade /s DVL, EVL
CL G ade
N
LINE C
ANOVA
Mean
sd
F
p
G ade I
54
3.62
0.91
G ade II A
33
3.61
0.81
G ade II B
14
4.60
1.61
25.54
<0.001
G ade III A
19
6.12
2.04
G ade III B
6
6.92
1.53
G ade IV
5
7.60
1.52
To al
131
4.39
1.74
Fig 13: CL g ade /s DVL, EVL
Table 13: CL g ade V/S AASI
CL G ade
N
AASI
ANOVA
Mean
sd
F
p
G ade I
54
0.361
0.093
G ade II A
33
0.362
0.088
0
5
10
15
20
25
30
35
40
45
G ade I G ade II A G ade II B G ade III A G ade III B G ade IV
Pe cen age
CL GRADE
0
1
2
3
4
5
6
7
8
I II A II B III A III B IV
CL G ade
LINE C
