Lightwand-guided nasotracheal intubation in oromaxillofacial surgery patients with anticipated difficult airways: a comparison with blind nasal intubation

Abstract

In oromaxillofacial surgery patients, the incidence of difficult airways is up to 15.4–16.9%. Blind nasal intubation remains a safe technique for difficult airway management in some remote areas where a fibreoptic bronchoscope is not always available. The lightwand is an easy-to-use, highly economical device, and can facilitate endotracheal intubation through illumination in the neck. The study aims to evaluate the efficacy of nasotracheal intubation using lightwand in oromaxillofacial surgery patients with difficult airways. One hundred and sixteen patients with difficult airways requiring nasotracheal intubation were randomly divided into a lightwand group and a blind group, with 58 cases in each group. The first attempt and overall success rates of lightwand intubation were 84.5% and 93.1%, respectively, which were higher than those of blind intubation (65.5% and 75.9%, respectively; P < 0.05). The total intubation time was 91.4 ± 27.7 s in the lightwand group and 130.7 ± 33.4 s in the blind group ( P < 0.001). Patients in the lightwand group also experienced more stable haemodynamic responses and less pharyngalgia. In conclusion, lightwand-guided nasotracheal intubation is superior to blind intubation in patients with difficult airways, with a higher success rate, more stable haemodynamic responses, and fewer postoperative complications.

Approximately 1–3% of general surgery patients have difficult airways, and difficult airways are the most important cause of anaesthesia-related morbidity and mortality. In oral and maxillofacial surgery, the incidence of difficult airway is up to 15.4–16.9%, due to temporomandibular joint (TMJ) illness, facial abnormalities, or fractures. The fibreoptic bronchoscope (FOB) is considered the gold standard for the management of difficult airways. However, blind nasal intubation remains a basic technique in developing countries, especially in remote areas where a FOB is not always available.

The lightwand is an easy-to-use, highly economical device, and has become a tool widely accepted in oral airway management under various clinical scenarios, including difficult airways. In contrast to direct laryngoscopy, lightwand-guided intubation does not depend on the anatomical structure of the upper airway, therefore the lightwand has an advantage in difficult airway management and is already sometimes regarded as the first-line option for a failed laryngoscopic intubation. In addition, the illumination of the lightwand is not influenced by blood or secretions, so the lightwand is more effective than the FOB in patients with active bleeding in the oral cavity following faciomaxillary trauma.

The purpose of this study was to compare the efficacy of lightwand-guided nasotracheal intubation with blind nasal intubation in oromaxillofacial surgery patients with anticipated difficult airways.

Materials and methods

One hundred and sixteen normotensive patients requiring nasotracheal intubation for elective oral and maxillofacial surgery were enrolled in this study between September 2009 and July 2012. Eighty-one patients were male and 35 female, and they were aged 18–76 years. All were ASA physical status I or II. The clinical diagnoses included TMJ ankylosis (12 cases), facial fracture (39 cases), recurrent oral cancer after surgery (37 cases), microstomia (11 cases), and severe constricted mandible (17 cases). Each patient had at least one of the following characteristics: (1) Mallampati class III or IV; (2) an interincisive distance of less than 3.0 cm; (3) thyromental distance of less than 6.0 cm; (4) body mass index (BMI) ≥ 30 kg/m 2 ; and (5) a history of failed laryngoscopic intubation. Patients were excluded if they had a coagulopathy, basal skull fracture, nasal bone fracture, nasal mass, upper airway foreign body, cervical instability, or a history of upper airway surgery. Patients were randomly allocated to one of two groups, with each group comprising 58 cases: a lightwand group receiving lightwand-guided intubation, and a blind group receiving blind intubation.

All patients were pre-medicated with intramuscular atropine 0.5 mg 30 min before anaesthesia. In the operating room, an intravenous infusion was set up and the radial artery was cannulated for invasive blood pressure monitoring under local anaesthesia using 2% lidocaine. Lidocaine 7–9 ml was sprayed on the mucosa of the nasopharynx, oropharynx, and laryngopharynx. Furthermore, the nasal mucosa was well prepared with 2% lidocaine jelly and three drops of 1% ephedrine hydrochloride nasal drops in each nostril in all patients.

The lightwand (Jerome Medical, Shanghai, China) consists of a stylet, light source, and tube fixer ( Fig. 1 A ). The first third of the lightwand stylet was bent into a gentle ‘J’ shape and then 2% lidocaine jelly was applied to lubricate the surface of the tracheal tube and lightwand to facilitate their mobility. The lightwand was inserted into the tracheal tube (ID 7.0 mm for males and 6.5 mm for females) until the distal end of lightwand (the location of the light spot) was 0.5 cm from the tip of the tube; the fixer was then fixed onto the lightwand.

Fig. 1
(A) The lightwand consists of a stylet (1), tube fixer (2), and light source (3). (B) A bright, well-circumscribed circle of light is seen above the cricothyroid membrane, indicating that the lightwand tip is located at the glottis site.

In both groups, the patient’s head was placed in a supine and neutral position. General anaesthesia was induced with midazolam (0.05 mg/kg) and fentanyl (1–2 μg/kg), and then 1% propofol was infused using target-controlled infusion until the patient lost consciousness. A muscle relaxant was not administered and the intubation was performed with spontaneous breathing. Before induction, 100% oxygen was administered for 5 min and oxygen saturation (SpO 2 ) was maintained at 100%.

The wider nasal cavity was chosen for intubation based on computed tomography, with the other as a back-up. In the lightwand group, the tracheal tube was inserted into the nostril and advanced perpendicularly until the tube tip broke through the postnaris, which was indicated by the sense of sudden decreased resistance. Then in dark, the lightwand was gently inserted into the tube with the right hand until the fixer touched the top of the tracheal tube. Guided by the light spot in the neck, the lightwand was pushed forward, rotated to the left or right, or moved slightly downward until a bright spot of light was visible at the cricothyroid membrane ( Fig. 1 B). Finally, the right hand fixed the lightwand, the left hand pushed the endotracheal tube into the trachea, and then the lightwand was withdrawn. In the blind group, the direction of the tracheal tube was guided through the patient’s breathing. The biggest breathing suggested the tube tip was located under the epiglottis, and then the tube was intubated into the trachea during inspiration. Successful intubation was confirmed by lung auscultation and end-tidal capnography, and then vecuronium (0.1 mg/kg) was administrated and mechanical ventilation was performed. An attending anaesthesiologist experienced with both lightwand-guided and blind intubation performed these procedures.

If the intubation was unsuccessful after three attempts or within 180 s, it was considered failed. For those that failed, a mouth gag, Magill forceps, McCoy laryngoscope, FOB, or tracheotomy was used for intubation, performed by a senior attending anaesthesiologist.

During intubation, if the SpO 2 was less than 90%, the lightwand was withdrawn, the opposite nostril and mouth were covered by hand, and ventilation through the tracheal tube was followed.

Each patient was monitored routinely during the entire procedure, including SpO 2 , electrocardiogram (ECG), and blood pressure. Mean arterial pressure (MAP) and heart rate (HR) were recorded at the following time-points: before induction/baseline value, T1; after induction, T2; during intubation, T3; 1 min after intubation, T4; and 5 min after intubation, T5. The first attempt and the total success rate of intubation, intubation time, and complications including pharyngalgia, hoarseness, and epistaxis after 24 h were recorded. The intubation time was defined as the period from the insertion of the tracheal tube into the nostril to successful intubation confirmed by end-tidal capnography.

Statistical methods

All data were analysed using SPSS 15.0 software (SPSS Inc., Chicago, IL, USA). Qualitative data are presented as the mean ± standard deviation. The independent samples t -test was used to determine the differences in basic clinical characteristics, MAP, HR, and intubation time between the two groups. Repetitive measures analysis of variance (ANOVA) was used to determine the differences in MAP and HR within groups. Quantitative data, presented as the proportion or number, were evaluated by χ 2 test. P -values of <0.05 were considered statistically significant.

Statistical methods

All data were analysed using SPSS 15.0 software (SPSS Inc., Chicago, IL, USA). Qualitative data are presented as the mean ± standard deviation. The independent samples t -test was used to determine the differences in basic clinical characteristics, MAP, HR, and intubation time between the two groups. Repetitive measures analysis of variance (ANOVA) was used to determine the differences in MAP and HR within groups. Quantitative data, presented as the proportion or number, were evaluated by χ 2 test. P -values of <0.05 were considered statistically significant.

Results

There were no significant differences in patient demographics or basic clinical characteristics, including gender, age, height, weight, BMI, Mallampati score, interincisive gap, thyromental distance, and history of failed laryngoscopic intubation, between the two groups ( Table 1 ).

Table 1
Demographic data and basic clinical characteristics of the patients in the two study groups.
Lightwand group ( n = 58) Blind group ( n = 58)
Gender, n
Male 43 38
Female 15 20
Age, years, mean ± SD 44 ± 16 41 ± 13
Height, cm, mean ± SD 169 ± 7 168 ± 7
Weight, kg, mean ± SD 69 ± 13 67 ± 13
Body mass index (kg/cm 2 ), n
<30 44 47
≥30 14 11
Mallampati score, n
I + II 15 9
III + IV 43 49
Interincisive gap, n
≥3 cm 26 23
<3 cm 32 35
Thyromental distance, n
≥6 cm 49 42
<6 cm 9 16
History of failed intubation, n
Yes 1 2
No 57 56
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Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Lightwand-guided nasotracheal intubation in oromaxillofacial surgery patients with anticipated difficult airways: a comparison with blind nasal intubation
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