The Effect of the Modified Jaw-Thrust Maneuver on the Depth of Sedation During Drug-Induced Sleep Endoscopy

Abstract

Study Objectives:

The modified jaw-thrust maneuver (MJTM) during drug-induced sleep endoscopy (DISE) is known to predict the treatment effect of mandibular advancement devices. However, its effect on the depth of sedation and potential to provoke arousal by awakening patients during the maneuver has not been studied so far. This study investigated the effect of the MJTM on the depth of sedation during DISE.

Methods:

Forty patients on whom the MJTM was performed during DISE were included. The effect of the maneuver was evaluated at the levels of the velum, lateral wall of the oropharynx, base of the tongue, and epiglottis. Obstruction was defined as the collapse of the upper airway exceeding 75%, and improvement with the MJTM was defined as the widening of the upper airway by more than 50% during the maneuver. A bolus injection of midazolam was used to induce sedation and control the depth of sedation (bispectral index value of 60 to 80).

Results:

Obstructions were present in the velum of all patients, lateral wall of the oropharynx of 13 patients, base of the tongue of 28 patients, and epiglottis of 6 patients. After the MJTM, improvement of the obstruction was observed in 57.5%, 61.5%, 82%, and 66.7% of patients with velum, lateral wall of the oropharynx, base of the tongue, and epiglottis obstructions, respectively. An increase in the bispectral index value of more than 20 was observed in 8 patients. Four patients awakened during the procedure.

Conclusions:

The MJTM significantly relieved obstruction during DISE, especially at the base of the tongue. However, this might have been caused by an increase in the degree of awakening during the maneuver. Therefore, MJTM’s effect on the depth of sedation may help in improving the degree of airway obstruction.

Citation:

Park D, Kim J-S, Heo SJ. The effect of themodified jaw-thrust maneuver on the depth of sedation during drug-induced sleep endoscopy. J Clin SleepMed. 2019;15(10):1503–1508.

BRIEF SUMMARY

Current Knowledge/Study Rationale: The modified jaw-thrust maneuver (MJTM) during drug-induced sleep endoscopy (DISE) has been used to predict the success of mandibular advancement devices. However, the MJTM may have an effect on the sedation and provoke arousal by awakening patients, which could be the cause for the improvement in airway obstruction. This study was conducted to investigate the effect of the MJTM on the depth of sedation during DISE.

Study Impact: The study found that the MJTM significantly relieved airway obstruction during DISE and increased the degree of awakening during the maneuver. Therefore, the effect of the MJTM on the depth of sedation may have contributed to relieving the airway obstruction.

INTRODUCTION

Obstructive sleep apnea (OSA) is a disease characterized by recurrent episodes of collapse of the upper airway during sleep.^1,2 The upper airway collapse leads to oxygen desaturation, and thereby causes several health risks. The main treatment options for OSA are continuous positive airway pressure (CPAP), surgery, and mandibular advancement device (MAD), positional therapy, and conservative therapy (weight loss, no alcohol ingestion, etc.).^3,4 CPAP is considered the first choice for the treatment of OSA.⁵ Although CPAP is highly efficacious in preventing collapse of the upper airway, there are problems of low tolerance and adherence.⁶ MAD is a useful alternative treatment method for patients with OSA who are intolerable to use of CPAP.⁷

Drug-induced sleep endoscopy (DISE) is a valuable method for assessing the obstruction pattern in the upper airway. It provides a dynamic and direct three-dimensional view of the upper airway.^8,9 Moreover, it shows the obstruction pattern during sleep, unlike the Müller maneuver or cephalometry, and it is performed without radiation exposure unlike video fluoroscopy or multidetector computed tomography.^8,9 Moreover, DISE has also been reported to be a useful tool to predict the effect of MAD on OSA when a modified jaw-thrust maneuver (MJTM) is performed during DISE because MAD and MJTM utilize the same mechanism, namely, the protrusion of the mandible.^6,10

In the clinical setting, however, the MJTM may cause pain and discomfort even when performed gently, and may affect the depth of sedation due to discomfort even during DISE.^2,5 Improvement in the airway obstruction, in addition to that caused by the MJTM itself, could arise from arousal and awakening of the patient during the maneuver. Hence, the predictive value of the MJTM during DISE for the effectiveness of MAD could be affected by the increase in arousal. This study aimed to determine the effect of the MJTM on the depth of sedation during DISE because, to our knowledge, this has not been studied thus far.

METHODS

Study Participants

The study included 40 patients who underwent DISE at our academic tertiary care center between December 2012 and March 2013. OSA was diagnosed in all patients based on type I polysomnography. We recorded the baseline characteristics of the patients, including their sex, age, body mass index (BMI), respiratory disturbance index (RDI), tonsil size, tongue position according to the Friedman Staging System, and Epworth Sleepiness Scale (ESS) score. Data were collected prospectively. The study was approved by the institutional review board of the Kyungpook National University Hospital, and all participants provided written informed consent.

Drug-Induced Sleep Endoscopy

DISE was performed as described previously.⁸ It was performed at an outpatient clinic by the same otorhinolaryngologist for all patients to prevent technical variations. The nasal mucosa was topically anesthetized and shrunk using gauze soaked with lidocaine (4%) and epinephrine (0.1%). After the mucosa was sufficiently anesthetized, the patient was placed in the supine position. Arterial oxyhemoglobin saturation was monitored using a pulse oximeter. Midazolam at a dose of 0.05 mg/kg was administered intravenously to induce sleep. If a bispectral index (BIS) range of 60 to 80 could not be achieved, an additional dose of midazolam of up to 9 mg was administered under close monitoring. When the patient had snoring or apnea, a nasopharyngeal fiberscope (VNL1130, KayPENTAX, Montvale, New Jersey, USA) was inserted through the nasal cavity, and the obstruction patterns were recorded. Two experienced sleep doctors evaluated the recorded videos blindly from the DISE examiner. The sites of obstruction were determined at the levels of the velum, lateral wall of the oropharynx, base of the tongue, and epiglottis as in the VOTE classification.¹¹ Configurations of the velum obstruction were classified into anteroposterior, lateral, and concentric. Obstruction was defined as the collapse of the upper airway exceeding 75%.

Bispectral Index

BIS monitoring, which is based on an algorithm developed from adult electroencephalogram values, is being used to measure anesthetic depth and reflects the level of consciousness of the patient.^12,13 Several factors, such as hypothermia, neurologic impairment, interference with medical devices, ketamine, or nitric oxide, have been known to be able to cause artifact or affect the BIS value.¹⁴ In patients with OSA, however, a standardized protocol for DISE with real-time monitoring of the depth of sedation using BIS after administration of midazolam was well established in the previous studies.^15,16 In this study, therefore, the depth of sedation was evaluated using the BIS and the reactions of the patients.

The BIS monitor collects raw encephalographic data through its sensors and uses an algorithm to analyze and interpret the data. The data are displayed numerically in the BIS view monitor. BIS values range from 0 to 100.¹² A value of 0 represents the absence of brain activity, and a value of 100 represents the awake state.¹⁴ Because a BIS value of 60 to 80 is generally recommended for DISE, an evaluation of the upper airway and MJTM during DISE was performed when a BIS value of 60 to 80 was achieved.^15,17 Before induction of sedation, a BIS sensor (Covidien Inc., Mansfield, Massachusetts, USA), along with BIS monitoring module (Model DSC-XP, Aspect Medical Systems, Minneapolis, Minnesota, USA) was applied over the patient's forehead for monitoring depth of sedation. The values of BIS were recorded before induction, and every 1 minute after administration of midazolam.

The MJTM and the Depth of Sedation

MJTM is a method to displace the mandible forward by pushing the posterior aspects of the lower jaw with the index and middle fingers¹⁸ (Figure 1). Although not exactly a jaw-thrust maneuver (a single-handed chin lift), the MJTM (two-handed chin lift) is used in DISE, and the use of the terms in this study are line with those in previous studies.^5,6,19–23

Figure 1. Depiction of modified jaw-thrust maneuver.

The modified jaw-thrust maneuver displaces the mandible forward by pushing the posterior aspects of the lower jaw with the index and middle fingers.

MJTM was gently performed to reduce the effect on the depth of sleep during DISE by an experienced otorhinolaryngologist who received a training of MJTM from a senior anesthesiologist. The mandible was advanced approximately 50% to 75% of maximal mandibular protrusion. To identify the effect of sensitivity to pain during the MJTM on the depth of sedation, we performed the maneuver before DISE in the wakeful state. The patients assessed pain using the visual analog scale (VAS), with scores ranging from 0 (no pain) to 10 (severe pain).

After evaluation of the obstruction pattern during DISE, the MJTM was performed and the improvement at the various obstruction sites was assessed. Improvement with the MJTM was defined as the widening of the upper airway by more than 50% during the maneuver. During the MJTM, changes in the BIS value and the reactions of the patients were recorded. The reactions were classified as alertness (opening of the eyes or speaking), hand movement toward the jaw in a sleep state, and minimal tossing and turning in a sleep state. We analyzed the correlation between pain sensitivity to the MJTM and the change in the depth of sedation during DISE.

Statistical Analysis

All statistical analyses were performed using the Statistical Package for the Social Sciences version 18.0 (SPSS Inc., Chicago, Illinois, USA). The age, BMI, RDI, size of the tonsil, position of the tongue according to the Friedman Staging System, and ESS score were presented as mean ± standard deviation and range. Kolmogorov-Smirnov test and Shapiro-Wilk test were used to test normality. McNemar test was used to analyze the improvement in the obstruction site after the MJTM. The paired t test was used to analyze the change in the BIS after the MJTM. The Spearman rank test was used to determine the relation between the change in the BIS after the MJTM during DISE and the VAS score after the MJTM in the wake state. A value of P < .05 was considered statistically significant.

RESULTS

Characteristics

The baseline characteristics of the patients, including sex, age, BMI, RDI, size of the tonsil, position of the palate according to the Friedman Staging Scale, and ESS score are presented in Table 1.

Table 1.

Baseline characteristics of the study group (n = 40).

The Effect of the MJTM on the Airway Obstruction

After the MJTM, there was a significant reduction in the obstruction of the velum, lateral wall of the oropharynx, and base of the tongue (P < .001, P = .013, and P < .001, respectively) (Figure 2). The obstruction of the epiglottis was reduced in 4 of 6 patients, but the change was not significant (P = .133). In the configuration of the velum, there was a significant reduction in the concentric obstruction after the MJTM (P < .001) (Figure 3). The anteroposterior and lateral obstruction improved in 4 of 6 (P = .125) and 3 of 5 (P = .079), respectively.

Figure 2. Comparison of the improvement of the upper airway obstruction before and after the modified jaw-thrust maneuver.

MJTM = modified jaw-thrust maneuver.

Figure 3. Changes of the obstruction pattern in the velum before and after the modified jaw-thrust maneuver.

MJTM = modified jaw-thrust maneuver.

The Effect of the MJTM on the Depth of Sedation

The mean BIS value in all patients significantly increased from 65.7 ± 5.7 (median, 64.0) to 74.1 ± 9.8 (median, 71.0) after the MJTM (P < .001) (Figure 4). During the MJTM, 12 patients (30%) showed a reaction to the maneuver: 4 patients became alert; 2 patients moved the hand toward the jaw in a sleep state; and 6 patients showed minimal tossing and turning in the sleep state (Figure 5). After the MJTM, the mean BIS value increased by over 20 in 8 patients (20%).

Figure 4. Changes in the mean bispectral index after the modified jaw-thrust maneuver.

BIS = bispectral index, MJTM = modified jaw-thrust maneuver.

Figure 5. Reactions caused by the modified jaw-thrust maneuver and the difference in the bispectral index during the maneuver.

BIS = bispectral index, MJTM = modified jaw-thrust maneuver.

Before DISE, the mean degree of pain caused by the MJTM was 2.8 ± 1.3 as measured by the VAS score. During DISE, the difference in the BIS before and after the MJTM was 8.5 ± 8.9. The Spearman correlation test revealed a moderate positive correlation between the VAS score and the difference in the BIS during the MJTM (r = .473) (Figure 6).

Figure 6. Correlation between the bispectral index during drug-induced sleep endoscopy and the visual analog scale of pain during the modified jaw-thrust maneuver performed before drug-induced sleep endoscopy.

BIS = bispectral index, VAS = visual analog scale.

DISCUSSION

Using BIS, this study demonstrated that the MJTM during DISE can affect the depth of sedation. Eichler at al⁶ reported that the MJTM is fast, simple, and can simulate a mandibular advancement similar to that expected with treatment with MAD. Hence, the MJTM during DISE has been used to predict the response of the patient to treatment with MAD.

Treatment with MAD is one of the main non-CPAP therapies for patients with sleep-disordered breathing.^4,24 Vroegop et al² proposed that the therapeutic effect of MAD on OSA can effectively be predicted using the simulation bite with the maximal comfortable protrusion of the mandible during DISE. However, the simulation bite device is not always easy to use given the time, cost, and capability of making it. Therefore, the MJTM during DISE, which can be performed without any additional device, is commonly used to predict the therapeutic effect of MAD on OSA, although consensus on its use has not been reached between researchers.

In the results of our study, improvement was observed in 57.5% of the patients with velum obstruction, 82% of those with tongue base obstruction, and 67% of those with epiglottis obstruction after the MJTM during DISE. This is consistent with a previous study in which the airway obstruction improved in the velum, base of the tongue, and epiglottis after the MJTM, with the obstruction at the base of the tongue and epiglottis having improved more than that at the velum.⁶ In previous studies, the criteria for the recommendation of MAD included a visible enhancement of the airway after using the MJTM and no residual airway obstruction.⁶ Considering these criteria for recommendation, the results of our study, which showed an improvement in the airway obstruction after the MJTM, indicated indirectly that the MJTM during DISE could be a predictor for treatment with MAD. However, despite the improvement in the airway obstruction, the MJTM during DISE had the tendency to decrease the depth of sedation and increase awakening due to pain, which was demonstrated by the increase in VAS score. These results indicate that the improvement in the airway obstruction may not be interpreted to be the effect of the MJTM alone because there is a tendency for the airway obstruction to occur more frequently in states of deep sleep.²⁵

Although we could not directly compare the efficacy of treatment with MAD with the improvement of the airway obstruction with the MJTM during DISE in this study, our study suggests that it may be necessary to cautiously interpret the cause of the improvement of the airway obstruction after the MJTM. This should especially be considered because previous studies record that there have been patients who did not respond to treatment with MAD despite having had an improvement in the airway obstruction after the MJTM. Simulation bite or other technique such as chin-lift maneuver can be tried in the patients with a substantial increase of the depth of sedation during MJTM.

There are several limitations to our study. First, because the number of patients with OSA who were included in our study was small, a general conclusion could not be made. This is because our study patients with OSA were enrolled prospectively. However, the prospective design of our study makes it different from other studies that are retrospective. Nevertheless, further studies with larger groups of patients with OSA are needed. Second, we have shown that the MJTM during DISE has a significant effect on the depth of sedation. However, we could not evaluate precisely how much of the improvement of the airway obstruction was affected by the MJTM. In fact, it was difficult to judge how much of the airway obstruction was reduced by the degree of awakening during the MJTM. However, considering the tendency of the airway obstruction to occur more frequently during states of deep sleep,²⁵ the effect of the depth of sedation on the airway obstruction through the MJTM cannot be completely ruled out. Further studies are necessary to investigate the extent to which the changes in the depth of sedation due to the MJTM affect the airway obstruction. Third, the standardization of MJTM has not been achieved, and there were no specific descriptions about the speed and the intensity while moving the mandible forward. Furthermore, there are no established standards for the degree of advancement. Ravesloot and de Vries¹⁹ advanced the mandible up to 5 mm and Vonk et al²⁶ tried to protrude the mandible less than 100%, aiming at approximately 50% to 75% protrusion. It is difficult to move the mandible in a precise amount. Last, there is still a controversy regarding using the MJTM to predict the effect of treatment with MAD. Although several studies report its effectiveness in predicting the success rate of treatment with MAD,^6,10 the study published by Vroegop et al² reported that there was no significant correlation between the effect of the chin-lift maneuver during DISE and the success of treatment with MAD. They postulate that performing DISE with an individually made test splint is a better way to predict the success of the treatment. Although the performance of the chin-lift maneuver may be different from that of the MJTM used in this study, the comparison between the two maneuvers is ambiguous.⁶ Further studies that compare the MJTM and the chin-lift maneuver may be necessary to evaluate the difference between the effects of these maneuvers exactly. However, the aim of our study was not to evaluate the predictability of the MJTM in the success of treatment with MAD, but to investigate the effects of the MJTM on the depth of sedation during DISE, which may also reduce the airway obstruction. Our study was the first to demonstrate that the MJTM significantly affected the depth of sedation during DISE.

CONCLUSIONS

The MJTM significantly relieved obstruction during DISE, especially at the base of the tongue. However, the improvement might have been caused, to an extent, by the MJTM provoking arousal by awakening the patients despite meticulous and soft manipulation. Therefore, it is possible that the effect of the depth of sedation during the MJTM might contribute to a degree of reduction of the airway obstruction. Additional research is needed to investigate the precise causal relationships between the depth of sedation, MJTM, and airway obstruction.

DISCLOSURE STATEMENT

All authors have seen and approved the manuscript. The authors report no conflicts of interest.

ABBREVIATIONS

BIS

bispectral index

BMI

body mass index

CPAP

continuous positive airway pressure

DISE

drug-induced sleep endoscopy

ESS

Epworth Sleepiness Scale

MAD

mandibular advancement device

MJTM

modified jaw-thrust maneuver

OSA

obstructive sleep apnea

RDI

respiratory disturbance index

VAS

visual analog scale