Clinical Application of Ultrasound-Guided Internal Branch of Superior Laryngeal Nerve Block in Patients with Severe COPD Undergoing Awake Fibreoptic Nasotracheal Intubation: A Randomized Controlled Clinical Trial

Figures & data

Figure 1 Flow diagram of the study.

Figure 2 The view of ultrasound-guided superior laryngeal nerve block. Hyoid bone, 1; thyroid cartilage, 2; thyrohyoid muscle, 3; thyrohyoid membrane, 4; superior laryngeal nerve, 5; the arrow denotes the puncture path of the needle.

Table 1 Patient and Procedure Characteristics in the Two Groups

Characteristic	Group S (n = 25)	Group C (n = 24)	P-value
Sex (n, male/female)	20/5	18/6	0.68*
Age (years)	69.5 ± 9.3	67.5 ± 10.9	0.50^#
ASA classification (n, III/IV)	7/18	5/19	0.56*
Weight (kg)	57.6 ± 9.7	56.2 ± 7.7	0.57^#
BMI (kg/cm^2)	21.3 ± 2.1	22.2 ± 2.6	0.19^#
PH	7.21 ± 0.05	7.19 ± 0.05	0.32^#
PaO2/FiO2	174 ± 23	177 ± 18	0.57^#
PaCO2 (mmHg)	81 ± 7.9	78 ± 6.8	0.20^#
Dexmedetomidine dose (μg)	34.5 ± 6.5	33.5 ± 4.9	0.57^#
Fentanyl dose (μg)	28.8 ± 4.8	28.1 ± 3.8	0.57^#

Notes: Data are presented as mean ± standard deviation or the number of patients. group S received ultrasound-guided superior laryngeal nerve block; group C was the control group. *Fisher’s exact test for statistical analysis. ^#Independent samples t-test for statistical analysis.

Abbreviations: ASA, American Society of Anaesthesiologists; BMI, body mass index; FiO₂, fraction of inspiration O₂; PaCO₂, partial pressure of arterial carbon dioxide; PaO₂, partial pressure of arterial oxygen.

Table 2 Time for Intubation, Comfort Score and Incidence of Adverse Reactions in the Two Groups

Characteristic		Group S (n = 25)	Group C (n = 24)	P-value
Time for intubation (sec)		66.2±14.8	107.3±17.0	<0.01^#
Comfort score		2.6±1.2	3.9±0.8	<0.01^#
Adverse reactions	NVDP(n)	3	5
	Cough (n)	2	3
	Body movement (n)	1	2
	Hypertension (n)	1	2
	Hypotension (n)	0	0
	Tachycardia (n)	0	1
	Bradycardia (n)	0	0
	Total (n)	7	13
	Incidence(%)	28.0	54.2	<0.01*

Notes: The data are presented as the number or percentage. group S received ultrasound-guided superior laryngeal nerve block; group C was the control group. ^#Independent samples t-test for statistical analysis. *Fisher’s exact test for statistical analysis.

Abbreviation: NVDP, Nausea or vomiting during procedure.

Figure 3 Comparison of the time for intubation (A), the incidence of adverse reactions (B) and the comfort score (C). (A and C) The data are expressed as the mean ± standard deviation compared with group C. The data were compared with an independent sample t-test; *P<0.01. (B) The data are expressed as the percentage, compared with group C. Data were compared with Fisher’s exact test; *P<0.01. Group S received ultrasound-guided superior laryngeal nerve block; group C was the control group.

Figure 4 Comparison of the mean arterial pressure (MAP) (A) and heart rate (HR) (B) between the groups immediately before intubation (T0); immediately after intubation to the laryngopharynx (T1); and immediately (T2), 5 min (T3) and 10 min (T4) after intubation (25 patients in group S and 24 patients in group (C). The data are expressed as mean ± standard deviation. ^#Based on analysis of variance (ANOVA), compared with T0, MAP and HR in group C was significantly higher at T1, T2, T3 and T4 (P<0.05). *Based on one-way ANOVA, MAP and HR in group S was significantly lower than in group C at T1, T2, T3 and T4 (P<0.05), whereas they were not significantly higher in group S(P>0.05). Based on one-way ANOVA, there was no significant difference in MAP and HR between groups at T0 (baseline) (P>0.05). Group S received ultrasound-guided superior laryngeal nerve block; group C was the control group.

Figure 5 Comparison of the norepinephrine (NE) (A) and Adrenaline (AD) (B) concentrations between the groups immediately before intubation (T0); immediately after intubation to the laryngopharynx (T1); and immediately (T2), 5 min (T3) and 10 min (T4) after intubation (25 patients in group S and 24 patients in group (C). The data are expressed as mean ± standard deviation. ^#Based on analysis of variance(ANOVA) compared with T0, NE and AD in group C was significantly higher at T1, T2, T3 and T4 (P<0.05), but not significantly higher in group S (P>0.05). *Based on one-way ANOVA, NE and AD in group S was significantly lower than in group C at T1, T2, T3 and T4 (P<0.05). Based on one-way ANOVA, there was no significant difference in NE and AD between groups at T0 (baseline) (P>0.05). Group S received ultrasound-guided superior laryngeal nerve block; group C was the control group.