Bispectral Index in Evaluating Effects of Sedation Depth on Drug-Induced Sleep Endoscopy

Abstract

achieve a target effect site (brain) concentration of propofol. However, patients may lose consciousness at variable effect site concentrations (Ce), with a higher Ce being associated with higher upper airway critical closing pressure.6,7 Most DISE procedures are started shortly after the patients lose consciousness. Objective:To evaluate the effect of sedation depth on druginduced sleep endoscopy (DISE). Methods: Ninety patients with obstructive sleep apnea (OSA) and 18 snorers underwent polysomnography and DISE under bispectral index (BIS)-guided propofol infusion at two different sedation levels: BIS 65-75 (light sedation) and 50-60 (deep sedation). Results: For the patients with OSA, the percentages of velopharynx, oropharynx, hypopharynx, and larynx obstructions under light sedation were 77.8%, 63.3%, 30%, and 33.3%, respectively. Sedation depth was associated with the severity of velopharynx and oropharynx obstruction, oropharynx obstruction pattern, tongue base obstruction, epiglottis anteroposterior prolapse and folding, and arytenoid prolapse. In comparison, OSA severity was associated with the severity of velopharynx obstruction, severity of oropharynx obstruction, and arytenoid prolapse (odds ratio (95% confi dence interval); 14.3 (4.7-43.4), 11.7 (4.2-32.9), and 13.2 (2.8-62.3), respectively). A good agreement was noted between similar DISE fi ndings at different times and different observers (kappa value 0.6 to 1, respectively 1 Drug-induced sleep endoscopy (DISE) has been used for decades to directly examine the upper airways in sedative-induced sleep and improve treatment outcomes by acting as an adjuvant tool to assess surgical or nonsurgical treatment options. 2-4Various sedation methods have been used to allow for the performance of DISE. Roblin introduced target-controlled infusion (TCI) of propofol to DISE to allow for better control of the sedation level.5 TCI of propofol uses computer-based pharmacokinetic and pharmacodynamic models to predict and Bispectral Index in Evaluating Effects of Sedation Depth on Drug-Induced Sleep EndoscopyYu-Lun Lo, MD BRIEF SUMMARYCurrent Knowledge/Study Rationale: Drug-induced sleep endoscopy (DISE) were performed under different sedative conditions and might affect upper airway obstructions. We aimed to evaluate the affects of sedation depth and obstructive sleep apnea severity on different upper airway obstruction patterns. Study Impact: Under DISE, sedation depth affected velopharynx and oropharynx obstruction severity, oropharynx obstruction pattern, tongue base obstruction, epiglottis anteroposterior prolapse and folding, and arytenoid prolapse; however, OSA severity was associated with velopharynx and oropharynx obstruction severity as well as arytenoid prolapse. Bispectral index guided DISE offers an objective and reproducible method to evaluate upper airway collapsibility.

The Effect of Sedating Agents on Drug‐Induced Sleep Endoscopy Findings

“…BIS monitoring, used by anesthetists to maintain loss of consciousness (LOC) and prevent intraoperative awareness, is used during DISE to ensure adequate sedation levels in an attempt to simulate natural sleep. Regarding the drug doses, studies have already shown the impact between superficial and deep sedation of the same drug on the BIS index and DISE findings . BIS is considered a reliable method for monitoring and accurately predicting the sedative depth when propofol and midazolam are used but not when other anesthetics such as nitrous oxide and ketamine are used .…”

“…Regarding the drug doses, studies have already shown the impact between superficial and deep sedation of the same drug on the BIS index and DISE findings. 42,43 BIS is considered a reliable method for monitoring and accurately predicting the sedative depth when propofol and midazolam are used but not when other anesthetics such as nitrous oxide and ketamine are used. [44][45][46][47] Dexmedetomidine, which acts on the alpha 2-adrenoceptors in the locus coeruleus, 24 produces physiological sleeplike phenomena by EEG and a characteristic arousable sedation, which is markedly different from that of other sedatives such as the GABA agonists propofol and midazolam.…”

European position paper on drug‐induced sleep endoscopy: 2017 Update

“…Although some studies have shown that the collapsibility of the UA increases with the depth of the sedation, according to Heiser et al, decision making does not change significantly if the sedation is lower than 60. Although lower levels of BIS have been related to N3 sleep phase, they could cause deep oxygen desaturation, significantly unsafe for the patient . BIS values may not be the same if dexmedetomidine is the drug of choice; moreover, there is variability among the patients in the level of sedation with the same BIS score.…”

Obstrükti̇f Uyku Apnesi̇ Hastalarinda Uyku Endoskopi̇si̇nde Pozi̇syon Ve Uyku Deri̇nli̇ği̇ne Göre Obstrüksi̇yon Derecesi̇ni̇n Değerlendi̇ri̇lmesi̇

“…Obstrüktif uyku apnesi (OSA) üst hava yolunun birçok seviyesinde obstrüksiyon ile karakterizedir (1). Bu obstrüksiyonun doğru bir şekilde değerlendirilmesi için çeşitli fizik muayene ve radyolojik tetkikler yapılmaktadır.…”