Incidence of Connected Consciousness after Tracheal Intubation: A Prospective, International, Multicenter Cohort Study of the Isolated Forearm Technique
[en] Background: The isolated forearm technique allows assessment of consciousness of the external world (connected consciousness) through a verbal command to move the hand (of a tourniquet-isolated arm) during intended general anesthesia. Previous isolated forearm technique data suggest that the incidence of connected consciousness may approach 37% after a noxious stimulus. The authors conducted an international, multicenter, pragmatic study to establish the incidence of isolated forearm technique responsiveness after intubation in routine practice. Methods: Two hundred sixty adult patients were recruited at six sites into a prospective cohort study of the isolated forearm technique after intubation. Demographic, anesthetic, and intubation data, plus postoperative questionnaires, were collected. Univariate statistics, followed by bivariate logistic regression models for age plus variable, were conducted. Results: The incidence of isolated forearm technique responsiveness after intubation was 4.6% (12/260); 5 of 12 responders reported pain through a second hand squeeze. Responders were younger than nonresponders (39 ± 17 vs. 51 ± 16 yr old; P = 0.01) with more frequent signs of sympathetic activation (50% vs. 2.4%; P = 0.03). No participant had explicit recall of intraoperative events when questioned after surgery (n = 253). Across groups, depth of anesthesia monitoring values showed a wide range; however, values were higher for responders before (54 ± 20 vs. 42 ± 14; P = 0.02) and after (52 ± 16 vs. 43 ± 16; P = 0.02) intubation. In patients not receiving total intravenous anesthesia, exposure to volatile anesthetics before intubation reduced the odds of responding (odds ratio, 0.2 [0.1 to 0.8]; P = 0.02) after adjustment for age. Conclusions: Intraoperative connected consciousness occurred frequently, although the rate is up to 10-times lower than anticipated. This should be considered a conservative estimate of intraoperative connected consciousness.
Disciplines :
Anesthesia & intensive care
Author, co-author :
Sanders, R. D.; Department of Anesthesiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WN, United States
Gaskell, A.; Department of Anaesthesia, Waikato Clinical School, University of Auckland, Hamilton, New Zealand
Raz, A.; Department of Anesthesiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WN, United States, Department of Anesthesia, Rambam Healthcare Campus, Haifa, Israel
Winders, J.; Department of Anaesthesia, Waikato Clinical School, University of Auckland, Hamilton, New Zealand
Stevanovic, A.; Department of Anesthesiology, University Hospital RWTH Aachen, Aachen, Germany
Rossaint, R.; Department of Anesthesiology, University Hospital RWTH Aachen, Aachen, Germany
Boncyk, C.; Department of Anesthesiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WN, United States
DEFRESNE, Aline ; Centre Hospitalier Universitaire de Liège - CHU > Service d'anesthésie - réanimation
TRAN, Gabriel ; Centre Hospitalier Universitaire de Liège - CHU > Service d'anesthésie - réanimation
Tasbihgou, S.; Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
Meier, S.; Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
Vlisides, P. E.; Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States
Fardous, H.; Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States
Hess, A.; Department of Anesthesiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WN, United States
Bauer, R. M.; Department of Anesthesiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WN, United States, Department of Anesthesiology and Critical Care, Houston Methodist Hospital, Houston, TX, United States
Absalom, A.; Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
Mashour, G. A.; Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States
BONHOMME, Vincent ; Centre Hospitalier Universitaire de Liège - CHU > Département d'Anesthésie et réanimation > Service d'anesthésie - réanimation
Coburn, M.; Department of Anesthesiology, University Hospital RWTH Aachen, Aachen, Germany
Sleigh, J.; Department of Anaesthesia, Waikato Clinical School, University of Auckland, Hamilton, New Zealand
Incidence of Connected Consciousness after Tracheal Intubation: A Prospective, International, Multicenter Cohort Study of the Isolated Forearm Technique
Sandin RH Enlund G Samuelsson P Lennmarken C Awareness during anaesthesia: A prospective case study. Lancet 2000 355 707 11
Sebel PS Bowdle TA Ghoneim MM Rampil IJ Padilla RE Gan TJ Domino KB The incidence of awareness during anesthesia: A multicenter United States study. Anesth Analg 2004 99 833 9, table of contents
Mashour GA Shanks A Tremper KK Kheterpal S Turner CR Ramachandran SK Picton P Schueller C Morris M Vandervest JC Lin N Avidan MS Prevention of intraoperative awareness with explicit recall in an unselected surgical population: A randomized comparative effectiveness trial. A nesthesiology 2012 117 717 25
Sanders RD Tononi G Laureys S Sleigh JW Unresponsiveness ≠ unconsciousness. A nesthesiology 2012 116 946 59
Tunstall ME Detecting wakefulness during general anaesthesia for caesarean section. Br Med J 1977 1 1321
Sanders RD Raz A Banks MI Boly M Tononi G Is consciousness fragile? Br J Anaesth 2016 116 1 3
Russell IF Sanders RD Monitoring consciousness under anaesthesia: The 21st century isolated forearm technique. Br J Anaesth 2016 116 738 40
Bauer M Böhrer H Aichele G Bach A Martin E Measuring patient satisfaction with anaesthesia: Perioperative questionnaire versus standardised face-to-face interview. Acta Anaesthesiol Scand 2001 45 65 72
Schneider G Wagner K Reeker W Hänel F Werner C Kochs E Bispectral Index (BIS) may not predict awareness reaction to intubation in surgical patients. J Neurosurg Anesthesiol 2002 14 7 11
Zbinden AM Maggiorini M Petersen-Felix S Lauber R Thomson DA Minder CE Anesthetic depth defined using multiple noxious stimuli during isoflurane/oxygen anesthesia. I. Motor reactions. A nesthesiology 1994 80 253 60
Dai S Perouansky M Pearce RA Isoflurane enhances both fast and slow synaptic inhibition in the hippocampus at amnestic concentrations. A nesthesiology 2012 116 816 23
Zand F Hadavi SM Chohedri A Sabetian P Survey on the adequacy of depth of anaesthesia with bispectral index and isolated forearm technique in elective Caesarean section under general anaesthesia with sevoflurane. Br J Anaesth 2014 112 871 8
St Pierre M Landsleitner B Schwilden H Schuettler J Awareness during laryngoscopy and intubation: Quantitating incidence following induction of balanced anesthesia with etomidate and cisatracurium as detected with the isolated forearm technique. J Clin Anesth 2000 12 104 8
Baraka A Louis F Dalleh R Maternal awareness and neonatal outcome after ketamine induction of anaesthesia for Caesarean section. Can J Anaesth 1990 37 641 4
Kocaman Akbay B Demiraran Y Yalcin Sezen G Akcali G Somunkiran A Use of the bispectral index to predict a positive awareness reaction to laryngeal mask airway-Fastrach insertion and intubation. Acta Anaesthesiol Scand 2007 51 1368 72
Russell IF The Narcotrend 'depth of anaesthesia' monitor cannot reliably detect consciousness during general anaesthesia: An investigation using the isolated forearm technique. Br J Anaesth 2006 96 346 52
Russell IF The ability of bispectral index to detect intra-operative wakefulness during isoflurane/air anaesthesia, compared with the isolated forearm technique. Anaesthesia 2013 68 1010 20
