Predisposing Factors of Difficult Tracheal Intubation Among Adult Patients in Aliabad Teaching Hospital in Kabul, Afghanistan – A Prospective Observational Study

Figures & data

Table 1 Mallampati Classification

Class	Structures Visible
I	Soft palate, fauces, pillars and uvula
II	Soft palate, fauces and uvula
III	Soft palate, base of uvula
IV	Hard palate only

Figure 1 Flow diagram of subject recruitment for the study.

Table 2 Socio-Demographic Characteristics of the Subjects (n=341)

Characteristics	Classification	n (%)
Gender	Female	148(43.40)
	Male	193(56.59)
Age group	<40	192(56.30)
	≤40	149(43.69)
Ethnicity	Tajiks	186(54.5)
	Pashtuns	76(22.3)
	Hazaras	66(19.4)
	Uzbeks	13(3.8)
ASA physical status	ASA Class III patients	13(3.7)
	ASA Class II patients	90(24.6)
	ASA Class I patients	238(69.79)

Table 3 Preoperative Airway Assessments and Their Distribution Among Surgical Patients in Aliabad Teaching Hospital

Preoperative Assessments	Classification	Frequency	Percent
Mallampati classes	Class IV	2	0.6
	Class III	24	7
	Class II	101	29.6
	Class I	214	62.8
Mouth opening	=<4 cm	24	7
	>4 cm	317	93
Thyromental distance	=<6 cm	25	7.3
	>6 cm	316	92.7
Inability to prognath	Overbite, Poor extension	34	10
	Normal bite, Easy to reverse	23	6.7
	No overbite, Good extension	284	83.3
Neck mobility and size category	<30° short neck	15	4.4
	≥30° short neck	9	2.6
	≥30° normal neck	317	93

Figure 2 Incidence of difficult intubation among study participants (Frequency).

Table 4 Results of Chi-Square and Logistic Regression Analyses for Socio-Demographic Characteristics Associated with Difficult Intubation

Characteristics		Difficult Intubation		ORC* (95% CI)	P	AOR**	P
		Present n (%)	Absent n (%)
Gender	Female	48 (32.4)	100 (67.6)	1.7 (1.0–2.7)	0.036
	Male	43 (22.3)	150 (77.7)	1		–	0.189
Age group	<40	16 (8.3)	176 (91.7)	11.1 (6.1–20.4)	0.001	15.775 (7.04–35.34)
	≤40	75 (50.3)	74 (49.7)	1		1	0.000
Ethnicity	Hazara ethnicity	25 (37.9)	41 (62.1)	1.9 (1.1–3.4)	0.022
	Other ethnicities	66 (24.0)	209 (76.0)	1		–	0.104
ASA physical status	Systemic disease patients	48 (46.6)	55 (53.4)	4.0 (2.4–6.6)	0.001	–	0.862
	ASA Class I	43 (18.1)	195 (81.9)

Notes: *Crude odds ratio. **Adjusted odds ratio. 1= Reference category.

Table 5 Results of Chi-Square and Logistic Regression Analyses for Significant Predictive Factors Associated with Difficult Intubation

Predictive Factors		Difficult Intubation		ORC* (95% CI)	AOR**	P
		Present n (%)	Absent n (%)
Mallampati classes	Difficult	19 (73.1)	7 (26.9)	9.2 (3.7–22.7)	–	0.097
	Easy	72 (22.9)	243 (77.1)
Mouth opening	=<4 cm	18 (75.0)	6 (25.0)	10.0 (3.8–26.1)	5.436 (1.119–26.417)	0.036
	>4 cm	73 (23.0)	244 (77.0)		1
Thyromental distance	=<6 cm	14 (56.0)	11 (44.0)	4.0 (1.7–9.1)	–	0.277
	>6 cm	77 (24.4)	239 (75.5)
Inability to prognath	Difficult	26 (76.5)	8 (23.5)	12.1 (5.2–28.0)	5.382 (1.725–16.792)	0.004
	Easy	65 (21.2)	242 (78.8)		1
Neck mobility and size	Difficult	17 (70.8)	7(29.2)	8.0 (3.2–20.0)	–	0.438
	Easy	74 (23.3)	243 (76.7)

Notes: *Crude odds ratio. **Adjusted odds ratio. 1= Reference category.