An evaluation of remifentanil-sevoflurane response surface models in patients emerging from anesthesia: model improvement using effect-site sevoflurane concentrations.

Johnson, Ken B

Syroid, Noah D

Gupta, Dhanesh K

Manyam, Sandeep C

Pace, Nathan L

LaPierre, Cris D

Egan, Talmage D

White, Julia L

Tyler, Diane

Westenskow, Dwayne R

United States

2015-06-30T18:02:55Z

2010-08

INTRODUCTION: We previously reported models that characterized the synergistic interaction between remifentanil and sevoflurane in blunting responses to verbal and painful stimuli. This preliminary study evaluated the ability of these models to predict a return of responsiveness during emergence from anesthesia and a response to tibial pressure when patients required analgesics in the recovery room. We hypothesized that model predictions would be consistent with observed responses. We also hypothesized that under non-steady-state conditions, accounting for the lag time between sevoflurane effect-site concentration (Ce) and end-tidal (ET) concentration would improve predictions. METHODS: Twenty patients received a sevoflurane, remifentanil, and fentanyl anesthetic. Two model predictions of responsiveness were recorded at emergence: an ET-based and a Ce-based prediction. Similarly, 2 predictions of a response to noxious stimuli were recorded when patients first required analgesics in the recovery room. Model predictions were compared with observations with graphical and temporal analyses. RESULTS: While patients were anesthetized, model predictions indicated a high likelihood that patients would be unresponsive (> or = 99%). However, after termination of the anesthetic, models exhibited a wide range of predictions at emergence (1%-97%). Although wide, the Ce-based predictions of responsiveness were better distributed over a percentage ranking of observations than the ET-based predictions. For the ET-based model, 45% of the patients awoke within 2 min of the 50% model predicted probability of unresponsiveness and 65% awoke within 4 min. For the Ce-based model, 45% of the patients awoke within 1 min of the 50% model predicted probability of unresponsiveness and 85% awoke within 3.2 min. Predictions of a response to a painful stimulus in the recovery room were similar for the Ce- and ET-based models. DISCUSSION: Results confirmed, in part, our study hypothesis; accounting for the lag time between Ce and ET sevoflurane concentrations improved model predictions of responsiveness but had no effect on predicting a response to a noxious stimulus in the recovery room. These models may be useful in predicting events of clinical interest but large-scale evaluations with numerous patients are needed to better characterize model performance.

https://www.ncbi.nlm.nih.gov/pubmed/19820241

ANE.0b013e3181afe31c

1526-7598

https://hdl.handle.net/10161/10242

eng

NIH Public Access

Anesth Analg

10.1213/ANE.0b013e3181afe31c

Adult

Analgesics

Anesthesia Recovery Period

Anesthetics, Combined

Anesthetics, Inhalation

Anesthetics, Intravenous

Computer Simulation

Consciousness

Dose-Response Relationship, Drug

Drug Synergism

Elective Surgical Procedures

Female

Fentanyl

Humans

Male

Methyl Ethers

Middle Aged

Models, Biological

Pain Measurement

Pain Threshold

Piperidines

Predictive Value of Tests

Pulmonary Alveoli

Recovery of Function

An evaluation of remifentanil-sevoflurane response surface models in patients emerging from anesthesia: model improvement using effect-site sevoflurane concentrations.

Journal article

Gupta, Dhanesh K|0000-0001-9505-595X

https://www.ncbi.nlm.nih.gov/pubmed/19820241

387

394

2

Anesthesiology

Anesthesiology, Neuroanesthesia

Clinical Science Departments

Duke

School of Medicine

Published

111