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Use of Tragus Pressure in Guiding Emergence From Anaesthesia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04331756
Recruitment Status : Recruiting
First Posted : April 2, 2020
Last Update Posted : April 2, 2020
Information provided by (Responsible Party):
National University Hospital, Singapore

Brief Summary:
The aims of this study is to evaluate the effectiveness of tragus pressure application in predicting or facilitating recovery from general anaesthesia, and compare the reliability of tragus pressure guided recovery/ emergence from anaesthesia to conventional modes of recovery

Condition or disease Intervention/treatment Phase
Anesthesia Procedure: Guiding Emergence From Anaesthesia With Tragus Pressure Procedure: Guiding Emergence From Anaesthesia Without Tragus Pressure Not Applicable

Detailed Description:
More than 70% of general anaesthesia are now performed with laryngeal mask (LMA) as the airway support device with state of the art intra-operative monitoring such as end tidal inhalational anaesthetic agent concentration and fronto-temporal electroencephalographic waves analysis such as the Bispectral index score (BIS) and entropy. The use of LMAs have promised rapid turnover allowing more patients to be operated in the limited operating theatres' time. This comes with the additional price of losing the continuity of advanced monitoring devices in the post anaesthesia units, the best being end tidal carbon dioxide analysis. When patients are brought to the PACU, much of the monitoring of emergence from anaesthesia is fairly done through clinical measures such as motor activity, response to auditory stimuli, tactile taps on shoulder and occasional nociceptive stimuli such as sternal rub. The timing of the responsiveness of these stimuli is unknown and nursing support teams are unable to suggest a frame of time on when the patient would recover. One of the main reasons for this unpredictability is that the recovery is not planned based on the last recorded end tidal anaesthetic agent concentration before leaving the operating theatre to be shifted to PACU, but by an approximation of time since the patient has arrived in PACU and by early signs of recovery such as appearance of forehead wrinkles or motor activities. The incidence of airway events such as laryngospasm, obstruction after removal of airway devices, desaturations from resedation/ apnea and rescue measures such as reintubation/ ambu ventilation needed globally and from our local data is up to 1-5%. The incidence is higher with children and patients with reactive airways, obesity and associated complicating comorbidities. Using BIS monitoring and end tidal agent analysis for each of the 18 post anaesthesia care unit bays for recovering patients scientifically is not a cost-effective initiative. The tragus pressure technique has been known to be appropriate stimuli that has adequate stimulation of reticular activating system (RAS) without producing nociception that can trigger airway events such a laryngospasm. Physiological sleep studies have quoted that tragus pressure can contribute to arousal without causing vagotonic response that is known to occur from 'startle response' or sudden emergence. Through this study we propose to evaluate the consistency in predictability of recovery from general anaesthesia and deep sedation with Ramsay score 3 through application of tragus pressure. The presence of reflex pupillary dilatation and early signs of recovery such as swallowing, gentle grimace and minor peripheral motor movements, we propose, gives a predictable plane of recovery from anaesthesia where the LMAs are removed safely without treading the dreaded stage 2 of excitability of anaesthesia. The proposed method also allows for continued responsiveness of patient with coherent verbal responses to auditory stimuli after safe removal of the airway, thereby minimizing the incidence of airway complication and hence the interventions required for the same. The continued alert responsiveness of the patient also allows for the post anaesthesia unit team to attend to other patients who might need more immediate care.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 750 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: Use of Tragus Pressure in Guiding Emergence From Anaesthesia- a Randomised Controlled Trial
Actual Study Start Date : July 1, 2017
Estimated Primary Completion Date : December 31, 2020
Estimated Study Completion Date : December 31, 2020

Arm Intervention/treatment
Guiding Emergence From Anaesthesia Without Tragus Pressure
Monitoring of patients and removal of laryngeal mask airway (LMA) as per routine practice in post anaesthesia care unit (PACU)
Procedure: Guiding Emergence From Anaesthesia Without Tragus Pressure
Usual clinical routine practice in guiding patients from emergence from anaesthesia post-surgery

Experimental: Guiding Emergence From Anaesthesia With Tragus Pressure
Tragus pressure documentation of planes of emergence from anaesthesia - regular 3-5 minutes follow up with Tragus pressure till removal of airway device or rejection of it by patient
Procedure: Guiding Emergence From Anaesthesia With Tragus Pressure
Use of tragus pressure in guiding patients from emergence from anaesthesia post-surgery

Primary Outcome Measures :
  1. Differences in time and ease of LMA removal between study and control group [ Time Frame: Postoperatively in PACU from a minimum of 30 minutes till safe recovery from anaesthesia (approximately 1 hour) ]
    To compare the reliability of tragus pressure guided emergence from anaesthesia to conventional modes of recovery, studied by the timing and ease of removal of LMA.

Information from the National Library of Medicine

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Ages Eligible for Study:   21 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • ASA 1 and 2
  • Surgeries with no risk of aspiration
  • Patients with laryngeal mask airway (LMA) insitu on arrival in the PACU
  • Surgery duration < 4 hours

Exclusion Criteria:

  • ASA 3 and 4
  • Organ failure with decompensation : Eg Heart failure, renal failure, liver failure
  • History of psychiatric illness or medications for mood control
  • Pregnancy
  • Patients for neurosurgery or GCS <12/15
  • LMA used for failed intubation or difficult airway protocol
  • Patients with no LMA on arrival in the PACU
  • Patients who are awake with LMA/ Responding to call on arrival at PACU

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04331756

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Contact: Ashokka Balakrishnan 97118855

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National University Hospital Recruiting
Singapore, Singapore, 110974
Contact: Ashokka Balakrishnan    97118855   
Sub-Investigator: Lian Kah Ti         
Sub-Investigator: Theng Wai Foong         
Sub-Investigator: Shree Venkatesan         
Sponsors and Collaborators
National University Hospital, Singapore
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Principal Investigator: Ashokka Balakrishnan National University Health System
Academy of Medical Royal Colleges. Safe Sedation for Healthcare Procedures. Standards and Guidance. London: Academy of Medical Royal Colleges, 2013. practice-for-healthcare-procedures-standards-and-guidance

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Responsible Party: National University Hospital, Singapore Identifier: NCT04331756    
Other Study ID Numbers: 2017/00071
First Posted: April 2, 2020    Key Record Dates
Last Update Posted: April 2, 2020
Last Verified: November 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by National University Hospital, Singapore:
Anaesthesia Emergence
Additional relevant MeSH terms:
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Central Nervous System Depressants
Physiological Effects of Drugs