Nasotracheal fiberoptic intubation: patient comfort, intubating conditions and hemodynamic stability during conscious sedation with different doses of dexmedetomidine

Airway nerve blocks for awake tracheal intubation: A meta-analysis of randomized control trials and trial sequential analysis

STUDY OBJECTIVE

This systematic review and meta-analysis aimed to assess the superiority of airway nerve blocks versus airway anesthesia without nerve blocks for awake tracheal intubation (ATI).

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs).

SETTING

All studies that assessed the superiority of airway anesthesia technique for awake tracheal intubation were searched in PubMed, Web of Science, Cochrane Library, Ovid Medline, Embase and Chinese databases (including China National Knowledge Infrastructure, Wanfang database, and VIP databases) and trial registry databases from their inception to December 2022.

PATIENTS

Adult patients included in randomized controlled trials comparing airway anesthesia with or without airway nerve blocks for ATI.

INTERVENTIONS

Airway nerve (including superior laryngeal nerve, glossopharyngeal nerve, or recurrent laryngeal nerve) blocks for ATI.

MEASUREMENTS

The primary outcome was the intubation time. Secondary outcomes were quality of intubating conditions (including patient reaction to placement of the flexible scope and tracheal tube, coughing and gagging, and patient satisfaction) and overall complications during ATI.

MAIN RESULTS

Fourteen articles with 658 patients were identified for analysis. When compared with airway anesthesia without nerve blocks, airway nerve blocks significantly reduced intubation time (standardized mean difference [SMD] -2.57, 95% CI -3.59- -1.56, p < 0.00001), improved anesthesia quality of ATI with higher no reaction to placement of the flexible scope and tracheal tube (relative risk [RR] 9.87; 95% CI 4.10-23.75, p < 0.00001), lower cough or gag reflex during intubation (RR 0.35, 95% CI 0.27-0.46, p < 0.00001), higher excellent patient satisfaction rate (RR 1.88, 95% CI 1.05-3.34, p = 0.03), and lower overall complications (RR 0.29, 95% CI 0.19-0.45, p < 0.00001). The overall quality of evidence was moderate.

CONCLUSIONS

Based on current published evidence, airway nerve blocks provide better airway anesthesia quality for ATI with a shorter intubation time, better intubation conditions including higher no reaction to placement of the flexible scope and tracheal tube, lower cough or gag reflex during intubation, higher excellent patient satisfaction, and lower overall complications.

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

Purpose

The aim was to investigate the time for intubation, adverse events and the comfort score of ultrasound-guided internal branch of superior laryngeal nerve block in patients with severe chronic obstructive pulmonary disorder (COPD) undergoing awake fibreoptic nasotracheal intubation.

Methods

Sixty patients with COPD who needed awake fibreoptic nasotracheal intubation were randomly and evenly divided into the ultrasound-guided internal branch of the superior laryngeal nerve block group (group S) and the control group (group C). All patients received procedural sedation with dexmedetomidine and adequate topical anaesthesia of the upper respiratory tract. Then, bilateral block was performed (with 2 mL of 2% lidocaine or the same volume of saline) followed by fibreoptic nasotracheal intubation. The primary outcomes were time for intubation, adverse reactions and comfort score. The secondary outcomes were haemodynamic changes and serum norepinephrine (NE) and adrenaline (AD) concentrations immediately before intubation (T0); immediately after intubation to the laryngopharynx (T1); and immediately (T2), 5 min (T3) and 10 min (T4) after intubation between the groups.

Results

Compared with group C, the time for intubation, the incidence of adverse reactions and the comfort score in group S were significantly lower (P<0.01). Compared with T0, the mean arterial pressure (MAP), heart rate (HR), NE and AD were significantly higher at T1 - T4 in group C (P<0.05), but were not obviously higher at T1 - T4 in group S (P>0.05). MAP, HR, NE and AD at T1-T4 were significantly lower in group S than in group C (P<0.05).

Conclusion

Ultrasound-guided internal branch of the superior laryngeal nerve block can effectively shorten the time for intubation, reduce the incidence of adverse reactions, improve comfort score, maintain considerable haemodynamic stability and inhibit stress response in patients with severe COPD undergoing awake fibreoptic nasotracheal intubation.

Recent Advances in the Clinical Value and Potential of Dexmedetomidine

Dexmedetomidine, a highly selective α2-adrenoceptor agonist, has sedative, anxiolytic, analgesic, sympatholytic, and opioid-sparing properties and induces a unique sedative response which shows an easy transition from sleep to wakefulness, thus allowing a patient to be cooperative and communicative when stimulated. Recent studies indicate several emerging clinical applications via different routes. We review recent data on dexmedetomidine studies, particularly exploring the varying routes of administration, experimental implications, clinical effects, and comparative advantages over other drugs. A search was conducted on the PubMed and Web of Science libraries for recent studies using different combinations of the words “dexmedetomidine”, “route of administration”, and pharmacological effect. The current routes, pharmacological effects, and application categories of dexmedetomidine are presented. It functions by stimulating pre- and post-synaptic α2-adrenoreceptors within the central nervous system, leading to hyperpolarization of noradrenergic neurons, induction of an inhibitory feedback loop, and reduction of norepinephrine secretion, causing a sympatholytic effect, in addition to its anti-inflammation, sleep induction, bowel recovery, and sore throat reduction effects. Compared with similar α2-adrenoceptor agonists, dexmedetomidine has both pharmacodynamics advantage of a significantly greater α2:α1-adrenoceptor affinity ratio and a pharmacokinetic advantage of having a significantly shorter elimination half-life. In its clinical application, dexmedetomidine has been reported to present a significant number of benefits including safe sedation for various surgical interventions, improvement of intraoperative and postoperative analgesia, sedation for compromised airways without respiratory depression, nephroprotection and stability of hypotensive hemodynamics, reduction of postoperative nausea and vomiting and postoperative shivering incidence, and decrease of intraoperative blood loss. Although the clinical application of dexmedetomidine is promising, it is still limited and further research is required to enhance understanding of its pharmacological properties, patient selection, dosage, and adverse effects.

Comparison between Intravenous Dexmedetomidine and Spray as you Go with 4% Lignocaine Versus Intravenous Fentanyl and Transtracheal Injection of 4% Lignocaine for Awake Nasotracheal Intubation with Flexible Vedioscope - A Randomized Single-Blind Prospective Study

Background:

Awake fiber-optic bronchoscopy-guided intubation is the method of choice in difficult airway which requires effective airway anesthesia to ensure patient comfort and acceptance.

Aims:

This study was conducted to assess the quality of airway anesthesia, patient comfort during intubation, and postoperative satisfaction of patients.

Settings:

Patients posted for surgeries under general anesthesia with Mallampati Grade I and II in a medical college. Patients were followed in the operation theater and postoperative ward.

Study Design:

This was a prospective randomized single-blind study.

Materials and Methods:

Group D received intravenous (i.v.) dexmedetomidine 1 μg.kg⁻¹ i.v. over 10 min and 3 ml of 4% lignocaine spray as you go (SAYGo). Group F received i.v. fentanyl 2 μg.kg⁻¹ over 10 min and transtracheal injection 3 ml of 4% lignocaine. Parameters assessed were endoscopic time, intubating condition, vocal cord position, cough severity, comfort during intubation, postoperative patient satisfaction, and any adverse effects such as sore throat, hoarseness, unpleasant memories, and hemodynamic response during intubation.

Statistical Analysis:

Independent Student's t-test, Mann–Whitney, Chi-squared test, or Fisher's exact test were used. P ≤ 0.05 was considered statistically significant.

Results:

Intubating conditions, vocal cord position, cough severity, comfort during intubation, and postoperative patient satisfaction were statistically significant (P ≤ 0.05) in favor of Group D though endoscopic time was longer.

Conclusion:

IV dexmedetomidine with SAYGo is effective than IV fentanyl with transtracheal block for awake fiber-optic videoscopic intubation in terms of intubating conditions, vocal cord position, cough severity, comfort during intubation, and postoperative satisfaction of patients with significant attenuation of postintubation hemodynamic response and better preservation of respiration though endoscopic time is more.

Anaesthesia for Awake Fiberoptic Intubation: Ultrasound-Guided Airway Nerve Block versus Ultrasonic Nebulisation with Lignocaine

Background: In anticipated difficult airway, awake fiberoptic guided intubation should be the ideal plan of management. It requires sufficient upper airway anesthesia for patient’s comfort and cooperation. We compared the efficacy of ultrasound guided airway nerve blocks and ultrasonic nebulisation with lignocaine for airway anesthesia before performing awake fibreoptic guided intubation. Methods: This prospective, randomised study included sixty consenting adult patients of both genders (American Society of Anesthesiologists' physical status 1–3) with anticipated difficult airway undergoing surgery. Ultrasound guided airway nerve blocks group received ultrasound-guided bilateral superior laryngeal (1 ml of 2% lignocaine) and transtracheal recurrent laryngeal (2 ml of 2% lignocaine) airway nerve blocks and ultrasonic nebulisation with lignocaine group received ultrasonic nebulisation of 4 ml of lignocaine 4%. The primary outcome was to compare the time required to intubate, whereas the secondary outcomes were to compare cough reflex and gag reflex, hemodynamic changes, number of attempts required, and  comfort score during awake fibreoptic guided intubation in both the groups. Results: The time taken for intubation was significantly lower in the ultrasound guided airway nerve blocks group 69.27±21.85 s than ultrasonic nebulisation with lignocaine group 92.43 ± 42.90 s (p = 0.015). Hemodynamic variables changed during the procedure but the values were comparable in both groups. There were no statistical differences in cough and gag reflexes, number of attempts, and comfort score in both groups. Conclusions: This study shows that significant lesser time required for performing awake fiberoptic intubation when patient received ultrasound guided airway nerve block in comparison to ultrasonic nebulisation for airway anaesthesia.

Intubating conditions and hemodynamic changes during awake fiberoptic intubation using fentanyl with ketamine versus dexmedetomidine for anticipated difficult airway: a randomized clinical trial

Background and objectives

Awake fiberoptic intubation (AFOI) is usually performed in patients with an anticipated difficult airway. Various sedation regimens are used during AFOI, however, most of them cause respiratory depression. The present study aims to compare the effectiveness of fentanyl with ketamine versus dexmedetomidine in search of a better sedation regimen which would achieve desirable intubating conditions and hemodynamic stability without causing respiratory depression.

Methods

This is a single centered randomized, double-blind clinical trial. Patients of both sexes between age 18–55 years and ASA (American Society of Anesthesiologists) physical status I–II with an anticipated difficult airway were randomly divided into two groups of thirty each. Group FK patients received intravenous fentanyl and ketamine, and group DX patients received dexmedetomidine, until Ramsay sedation scale ≥ 2. Heart rate (HR), mean blood pressure (MBP), oxygen saturation (SpO₂), respiratory rate (RR), endoscopy time, intubation time, first end-tidal carbon dioxide (ETCO₂) after intubation, endoscopist satisfaction score, and patient discomfort score were recorded during the study period. The level of recall was assessed on the next postoperative day.

Results

Endoscopist satisfaction score was better in group DX patients (p < 0.05). There was a smaller variation in HR and MBP from baseline with dexmedetomidine compared to fentanyl with ketamine. First ETCO₂ after intubation was higher in group FK patients (p <  0.05). No significant difference was found in patient discomfort score, intubation time, RR, SpO₂ and level of recall of the event.

Conclusions

The use of dexmedetomidine in AFOI provides better intubating conditions and hemodynamic stability compared to fentanyl with ketamine.

A Randomized Controlled Study Comparing Dexmedetomidine-Midazolam with Fentanyl-Midazolam for Sedation during awake Fiberoptic Intubation in Anticipated Difficult Airway

Background:

Awake fibreoptic nasotracheal intubation is an effective technique for the management of patients with difficult airways. Adequate sedation with effective topicalization of the airway is important to overcome discomfort and achieve intubation successfully.

Aim and Objectives:

Our aim was to compare the effectiveness of dexmedetomidine-midazolam with fentanyl-midazolam infusion for providing conscious sedation during fibreoptic intubation in patients with anticipated difficult airway under topical anaesthesia.

Materials and Methods:

Thirty adult patients of ASA physical status classification I and II with anticipated difficult airway and planned for elective awake nasal fibreoptic intubation under conscious sedation were randomly allocated into two groups. Dexmedetomidine 1 μg.kg-1 diluted in 50 ml saline was infused in Group DM over 10 min and Fentanyl 2 μg.kg-1 diluted in 50 ml saline was infused in Group FM over 10 min. Topicalization of the airway was done in all patients. All patients were assessed for sedation score, ease of endotracheal tube placement, patient comfort and cooperation, tolerance to endotracheal tube, any adverse events and recall of procedure.

Results:

The score of the modified OAA/S was comparable between the groups (P > 0.05). Quality of AFOI was comparable in both groups (P > 0.05). The intubation time and first EtCO2 were significantly lower in dexmedetomidine group (P <0.05). Group DM also showed better hemodynamics and less episodes of desaturation than Group FM.

Conclusion:

Fentanyl-midazolam and dexmedetomidine-midazolam are both effective for awake fiberoptic intubation under topical anesthesia. Dexmedetomidine allows better endurance and more stable hemodynamics.

Evaluation of retrograde intubation with different doses of dexmedetomidine infusion: A randomised controlled trial

Background

Retrograde intubation is one of the well-described and alternative methods of difficult airway management. It requires effective sedation and patient preparation. Study was done to evaluate intubating conditions during retrograde guided intubation with two different doses of dexmedetomidine.

Methods

This prospective randomized double blind parallel group trial was planned on 60 patients with difficult airway. Patients were divided in two groups to receive either dexmedetomidine 1.0 μg/kg (Group A) or dexmedetomidine 1.5 μg/kg (Group B) by intravenous (IV) route. The Modified Observer Assessment Awareness and Sedation (OAA/S) was measured as primary outcome and ease of intubation, facial grimace score, cough severity, hemodynamic response, patient recall and discomfort were assessed as secondary outcome during awake retrograde intubation.

Results

Groups were comparable in terms of demographic and baseline parameters. OAA/S (P = 0.001), cough severity (P < 0.001), facial grimace score (P < 0.001), grading of discomfort during procedure (P < 0.001) and recall of procedure scale (P = 0.038) were found significantly better/lower in Group B as compared to Group A. Hemodynamic parameters were better in Group B and showed significant difference during the retrograde intubation. However, ease of intubation scale, intubating time and complications were not significantly different (P > 0.05) between the two groups.

Conclusion

Retrograde intubation can be easily learned and performed with minimal complications. Dexmedetomidine in a dose of 1.5 μg/kg IV is optimum and safe for retrograde intubation with clinically manageable side effects.

Preoxygenation in difficult airway management: high-flow oxygenation by nasal cannula versus face mask (the PREOPTIDAM study). Protocol for a single-centre randomised study

INTRODUCTION

Although preoxygenation and airway management respond to precise algorithms, difficult intubation (DI) remains a daily challenge in intensive care units and in the operating rooms because of its frequent complications, including hypoxaemia. To prevent desaturation during DI, high-flow oxygenation by nasal cannula (HFNC) could prove beneficial. Indeed, contrary to standard preoxygenation device, it can be held in place throughout the intubation trying to perform apnoeic oxygenation during DI. Hence, recent guidelines recommend HFNC during DI, but its relevance has never been evaluated in this setting in a large randomised study until now.

METHODS AND ANALYSIS

The PREOPTIDAM trial is a prospective, single-centre, randomised, controlled study in Nantes University Hospital. In anticipated DI, we hypothesised that HFNC can decrease the incidence of desaturation ≤94% or face mask ventilation from 16% to 4% compared with standard device. Using a two-sided t-test with a first species risk of 5% and 80% power, a total of 186 patients will be included. Using a computer-generated randomisation, with a 1:1 allocation ratio, patients will be randomised to HFNC or face mask preoxygenation. Randomisation will be stratified on intubation sequence: Rapid sequence intubation or awake fibreoptic intubation. The primary objective is to determine whether HFNC is more efficient than standard oxygenation techniques to prevent desaturation ≤94% or face mask ventilation during DI. Intent-to-treat and per-protocol analysis are planned for the primary outcome.

ETHICS AND DISSEMINATION

The study project has been approved by an independent ethics committee. Written informed consent will be obtained before study inclusion. Participant recruitment begins in September 2018. Results will be submitted to international peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

NCT03604120.

Comparison between lignocaine nebulization and airway nerve block for awake fiberoptic bronchoscopy-guided nasotracheal intubation: a single-blind randomized prospective study

BACKGROUND

The preferred management strategy for difficult airways is awake fiberoptic bronchoscopy-guided intubation, which requires effective airway anesthesia to ensure patient comfort and acceptance. This randomized single-blind prospective study was conducted to compare lignocaine nebulization and airway nerve block for airway anesthesia prior to awake fiberoptic bronchoscopy-guided intubation.

METHODS

Sixty adult patients scheduled for surgical procedures under general anesthesia were randomly allocated to two groups. Group N received jet nebulization (10 ml of 4% lignocaine) and Group B received bilateral superior laryngeal and transtracheal recurrent laryngeal nerve blocks (each with 2 ml of 2% lignocaine) followed by fiberoptic bronchoscopy-guided nasotracheal intubation. All patients received procedural sedation with dexmedetomidine. The intubation time, intubating conditions, vocal cord position, cough severity, and degree of patient satisfaction were recorded. Student's t test was used to analyze parametric data, while the Mann-Whitney U test was applied to non-parametric data and Fisher's test to categorical data. P values < 0.05 were considered statistically significant.

RESULTS

The time taken for intubation was significantly shorter in Group B [115.2 (14.7) s compared with Group N [214.0 (22.2) s] (P = 0.029). The intubating conditions and degree of patient comfort were better in Group B compared with Group N. Although all patients were successfully intubated, patient satisfaction was higher in Group B.

CONCLUSIONS

Airway nerve blocks are preferable to lignocaine nebulization as they provide superior-quality airway anesthesia. However, nebulization may be a suitable alternative when a nerve block is not feasible.

Hemodynamic Responses and Safety of Sedation Following Premedication with Dexmedetomidine and Fentanyl during Fiberoptic-assisted Intubation in Patients with Predicted Difficult Airway

Background:

Awake fiberoptic intubation (AFOI) is the gold standard for the management of predicted difficult airway, and inappropriate sedation is a major cause leading to its failure.

Aims:

The primary objective was to compare the heart rate (HR) changes that accompany AFOI following sedation with dexmedetomidine and fentanyl. Secondary objectives included comparison of changes in blood pressure, patient comfort, ease of intubation, and degree of sedation.

Settings and Designs:

This prospective double-blinded randomized study was conducted in a tertiary care institution.

Subjects and Methods:

Forty patients with anticipated difficult airway requiring AFOI were included in the study. Group A received dexmedetomidine 1 μg/kg whereas Group B received fentanyl 2 μg/kg. After topical anesthesia of the airway, AFOI was performed.

Statistical Analysis Used:

Fisher's exact test, independent two-sample t-test, and Mann–Whitney U-test were used as applicable.

Results:

The hemodynamic parameters were comparable in both the groups except at 1 min postintubation when fentanyl group had significantly higher HR. There were lower alertness and muscle tone scores in dexmedetomidine group. Total comfort score was significantly higher in fentanyl group. Though more patients in dexmedetomidine group showed that no reaction to intubation and more patients in fentanyl had slight grimacing, the difference was insignificant. The ease of intubation was similar in both the groups.

Conclusion:

Though dexmedetomidine1 μg/kg and fentanyl 2 μg/kg premedication results in comparable hemodynamics and ease of intubation, in view of enhanced patient comfort, dexmedetomidine premedication is advantageous in patients with anticipated difficult airway undergoing AFOI.

Evaluation of different doses of dexmedetomidine alone versus the combination of dexmedetomidine and fentanyl in sedation during awake fiberoptic intubation in oral cancer surgery patients: A prospective, randomized, double-blind clinical trial

BACKGROUND

Awake fiberoptic intubation (AFOI) is one of the principal techniques in the management of difficult airway in oral cancer surgery. We hypothesized that the addition of a small dose of fentanyl could improve the sedative criteria of dexmedetomidine during AFOI technique, without the need to increase the dose of dexmedetomidine which may be associated with airway compromise.

PATIENTS AND METHODS

One hundred and fifty American Society of Anesthesiologists physical status 1 and 2 patients planned for AFOI for oral cancer surgery patients were allocated into three groups (fifty patients each). Group D1: Received an infusion of 1 μcg/kg dexmedetomidine diluted in 50 ml saline over 20 min. Group D2: Received an infusion of 2 μcg/kg dexmedetomidine diluted in 50 ml saline over 20 min. Group DF: Received an infusion of 1 μcg/kg dexmedetomidine added to 1 μcg/kg fentanyl diluted in 50 ml saline over 20 min. AFOI was done by topical anesthesia and with the same technique in all patients. All patients were assessed for: airway obstruction, intubation scores (vocal cord movement, coughing, and limb movement), fiberoptic intubation scores, and hemodynamic variables. Any episode of bradycardia or hypoxia was recorded and managed.

RESULTS

Group D2 showed more incidence of airway obstruction than the other two groups. Limb movement scores were more in Group D1 compared to the other two groups. All groups were comparable as regard fiberoptic intubation scores, coughing, and vocal cord opening scores.

CONCLUSION

Adding a low dose of fentanyl (1 μcg/kg) to a low dose of dexmedetomidine can prevent the risk of airway obstruction associated with increasing the dose of dexmedetomidine while achieving the same favorable intubation scores.

Awake orotracheal fibre-optic intubation: Comparison of two different doses of dexmedetomidine on intubation conditions in patients undergoing cervical spine surgery

Background and Aims

Awake fibre-optic intubation (AFOI) is an integral part of anaesthetic management of difficult airways. Conscious sedation is essential to assist AFOI. This study compared two different doses of dexmedetomidine in combination with topical spray and airway blocks for awake orotracheal fibre-optic intubation in patients undergoing elective cervical spine surgery with rigid cervical collar in situ.

Methods

A randomized, prospective, comparative study design was conducted in sixty patients divided into two groups: Group (L) (n = 30) patients received low dose of dexmedetomidine (0.5 μg/kg) along with airway blocks and Group (H) (n = 30) patients received standard dose of dexmedetomidine (1 μg/kg) along with airway blocks. Both the groups received dexmedetomidine infusion over 10 min followed by airway block. Quantitative data were analysed by applying Student's t-test whereas qualitative data were analysed with Chi-square test. The objectives were to compare patients' Observer's Assessment of Alertness/Sedation scale (OAA/S) as primary outcome and other variables such as endoscopy, intubation condition, tolerance and haemodynamic stability among low and standard doses of dexmedetomidine.

Results

Group H had more favourable OAA/S score than that of Group L, but endoscopy and intubation time, patient tolerance, vocal cord and limb movement and satisfaction score did not differ significantly between the groups. There were no significant haemodynamic differences between the two groups.

Conclusion

The 0.5 μg/kg dose of dexmedetomidine was found optimal and effective in combination with topical spray and airway blocks for awake orotracheal fibre-optic intubation for patients undergoing elective cervical spine surgery.

Dexmedetomidine-midazolam versus Sufentanil-midazolam for Awake Fiberoptic Nasotracheal Intubation: A Randomized Double-blind Study

BACKGROUND

Awake fiberoptic intubation (AFOI) is usually performed in the management of the predicted difficult airway. The aim of this study was to evaluate the feasibility of dexmedetomidine with midazolam (DM) and sufentanil with midazolam (SM) for sedation for awake fiberoptic nasotracheal intubation.

METHODS

Fifty patients with limited mouth opening scheduled for AFOI were randomly assigned to two groups (n = 25 per group) by a computer-generated randomization schedule. All subjects received midazolam 0.02 mg/kg as premedication and airway topical anesthesia with a modified "spray-as-you-go" technique. Group DM received dexmedetomidine at a loading dose of 0.5 μg/kg over 10 min followed by a continuous infusion of 0.25 μg·kg-1·h-1, whereas Group SM received sufentanil at a loading dose of 0.2 μg/kg over 10 min followed by a continuous infusion of 0.1 μg·kg-1·h-1. As necessary, since the end of the administration of the loading dose of the study drug, an additional dose of midazolam 0.5 mg at 2-min intervals was given to achieve a modified Observers' Assessment of Alertness/Sedation of 2-3. The quality of intubation conditions and adverse events were observed.

RESULTS

The scores of ease of the AFOI procedure, patient's reaction during AFOI, coughing severity, tolerance after intubation, recall of the procedure and discomfort during the procedure were comparable in both groups (z = 0.572, 0.664, 1.297, 0.467, 0.895, and 0.188, respectively, P > 0.05). Hypoxic episodes similarly occurred in the two groups, but the first partial pressure of end-tidal CO2after intubation was higher in Group SM than that in Group DM (45.2 ± 4.2 mmHg vs. 42.2 ± 4.3 mmHg, t = 2.495, P < 0.05).

CONCLUSIONS

Both dexmedetomidine and sufentanil are effective as an adjuvant for AFOI under airway topical anesthesia combined with midazolam sedation, but respiratory depression is still a potential risk in the sufentanil regimen.