2014 / 10 / 21 R2 VS Introduction Drug Drug- -induced sleep - - PowerPoint PPT Presentation

2014 / 10 / 21 R2 林書瑜 VS 劉宏濱 主任

Introduction

• Drug

Drug-

• induced sleep endoscopy (DISE

induced sleep endoscopy (DISE) ) uses sedative-hypnotics to induce moderate obstruction to facilitate anatomic differentiation of obstructive physiolygy.

A diagnostic tool for Obstructive sleep apnea (OSA) Common collapse sites: palate, pharyngeal wall, tongue

base

Real time visual observation of the airway May also provide prognostic information

Introduction

• Polysomnography

Polysomnography: :

Sleep disorder diagnosis Sleep-related symptom evaluation Monitors : Monitors :

Electroencephalogram (EEG) Electro-oculogram (Eye movement) Electromyogram (muscle activity) Electrocardiogram (EKG) Nasal pressure transducer Oronasal thermistor (Air flow) Oxygen Saturation

Introduction

• Polysomnography

Polysomnography: :

Introduction

Obstruction commonly, but not always, occurs

contemporaneously with loss of consciousness.

• Propofol

Propofol :

Reliable prediction of the necessary porpofol dose to Reliable prediction of the necessary porpofol dose to

achieve and maintain obstruction without causing prolonged loss of consciousness or oxygen desaturation is challenging !

Introduction

• Propofol

Propofol : :

Manual bolus

Experienced practitioner to obtain consistent results

Target-controlled infusion (TCI) Target-controlled infusion (TCI)

Not available in North America… Small serial increments in the target to achieve the

desired clinical end point => time-consuming porcess

Introduction

Both Manual and TCI approaches assume that the

anesthesiologist can surmise the appropriate target level for each patient.

We have previously demonstrated in simulation a method

for producing a continuously increasing probability of loss for producing a continuously increasing probability of loss

• f consciousness with a simple sequence of infusion rates.

We hypothesized that such an approach, with a hybrid

pharma-cokinetic/pharmacodynamic model, would permit reliable and efficient titration of propofol to an end point of visible airway collapse and/or loss of genioglossus tone in a population with severe OSA.

Method

97 patients were enrolled in a prospective study of

transoral robotic resection of the tongue base

The apnea

apnea-

• hypopnea

hypopnea index (AHI) index (AHI) for each patient was recorded from the sleep study was recorded from the sleep study

Defined as cessation of breathing for 10 seconds or more

• The

The saturation saturation nadirs nadirs

The lowest oxygen saturation during the night

Method

All patients were screened with DISE with

DISE with propofol propofol infusions infusions determined by custom software written in MATLAB

The system uses the Cortínez et al. pharmacokinetic model

and the Johnson pharmacodynamic model to determine an and the Johnson pharmacodynamic model to determine an infusion sequence comprised a bolus, initial infusion, secondary infusion, and a time for transition from the initial to secondary infusion using the age and weight of the individual patient.

PROPOFOL PHARMACOKINETIC MODEL

the model of Cortínez et al

PROPOFOL PHARMACODYNAMICS MODEL

The model of Johnson et al.

Method

Propofol was administered by an anesthesiologist.

No topical anesthesia / No other IV drugs

2L/min supplemental oxygen Pulse oximetry Pulse oximetry A Baxter AS50 pump:

Initial bolus and infusion rates

as determined by the control system

Method

Bronchoscope Observation of the pharynx was performed for a

sufficient period to obtain images of the anatomic site(s) of obstruction. site(s) of obstruction.

Comparison of saturation nadirs

saturation nadirs from DISE and polysomnography was performed with both the paired and unpaired Student t test.

Results

Patient characteristics

Results

The median time to obstruction, as determined by the

• torhi-nolaryngologist, was 3.8 minutes.

The mean, predicted effect-site concentration of propofol

at obstruction was 4.2 ± 1.3 mcg/mL. at obstruction was 4.2 ± 1.3 mcg/mL.

The median saturation nadir during DISE was significantly

higher (91.4 ± 5.1% IQR) than that during standard sleep studies (81.0% ± 11.2% IQR)

Nadir oxygen saturation: The lowest oxygen saturation during the night

Discussion

DISE with sedation-hypnotics:

Midazolam regimen Propofol by TCI or manual bolus In children: dexmedetomidine after sevoflurane In children: dexmedetomidine after sevoflurane

induction has been reported

Discussion

Narrow range of anesthetic depth

Patients with AHI > 30 (severe OHA)

Most present study excluded higher risk p’ts with BMI>30

kg/m2 kg/m

Reports of desaturation requiring bag-mask ventilation

are not uncommon

Recent study: Manual group: 65% V.S the TCI group : 5%

The effective sedation seen in this study with a low rate of

desaturation and infrequent need for airway support is an important result !

Discussion

The lowest saturation measured in our study (patients

received oxygen at 2 L/min via oral cannula) was 74%.

The mean oxygen saturation value was significantly higher

than the mean during polysomnography and was than the mean during polysomnography and was comparable with that reported by De Vito during TCI infusion.

Discussion

The extent of desaturation in obese patients with OSA is

multifactorial.

In addition to obstruction or apnea, loss of functional

residual capacity during sleep and the balance of metabolic residual capacity during sleep and the balance of metabolic rate and oxygen delivery under the effects of propofol also play a role.

Discussion

• TCI

TCI:

Good reliability but require slow titration Predicted effect-site concentration 2.0 ~ 4.8 μg/mL to

achieve obstruction have been reported with the achieve obstruction have been reported with the Schnider or Marsh propofol models

The predicted effect-site concentration for obstruction we

• bserved (4.2 ±

± ± ± 1.3 μg/mL) when using the Cortinez is in a range of similar magnitude.

Discussion

In one study by De Vito et al. the average time for the

procedures :

the TCI group => 15.2 minutes the manual control group => 6.2 minutes the manual control group => 6.2 minutes

The mean time to obstruction employing our control

system was 3.9 minutes, which is comparable with the manual approach and substantially faster than with TCI control in published studies.

Conclusions

• Propofol

Propofol infusion strategy infusion strategy

Require limited experience with propofol dose selection Produce airway obstruction faster the TCI based system O desaturation is within clinically acceptable range O2 desaturation is within clinically acceptable range

Thanks for your attention !