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Capnography Monitoring in the Bronchoscopic Sedation

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. Read our disclaimer for details. Identifier: NCT02848118
Recruitment Status : Completed
First Posted : July 28, 2016
Last Update Posted : March 9, 2017
Information provided by (Responsible Party):
Yu-Lun Lo, Chang Gung Memorial Hospital

Brief Summary:
Procedure sedation of flexible bronchoscopy (FB) comforts patients undergoing FB. Hypoventilation during FB is a concern. The investigators investigate the feasibility of monitoring capnography in FB sedation.

Condition or disease Intervention/treatment Phase
Hypoventilation Device: A nasal-oral cannula of capnography Other: Observer Assessment of Alertness and Sedation scale Not Applicable

Detailed Description:

Patients undergoing flexible bronchoscopy (FB) experience procedure-related symptoms. Current guidelines of FB recommend sedation to all patients undergoing FB, except when there are contraindications. Propofol or benzodiazepines plus an opioid are the common combination used to improve patient tolerance and satisfaction during FB. However, controversy about combining propofol and opioids persists because of the risk of over-sedation and cardiopulmonary depression.

While transition from alert into sedation during induction, like sleep, the respiratory drive and muscle tone of respiratory muscle and upper airway attenuate, which contribute hypoventilation and upper airway collapse, and further hypoxemia. Detection of cardiopulmonary depression traditionally has relied on continuous monitoring of heart rate, respiratory rate, and oxygen saturation. However, it has been shown that these monitors could not recognize hypoventilation early. Similar with other published data, around 40% of hypoxemia event occurred during FB sedation in our hospital. Further analysis of our data revealed around 15% event occurred during sedative induction.

Capnography is the noninvasive measurement of the partial pressure of carbon dioxide (CO2) from the airway during ventilation. The maximum partial pressure of CO2 obtained at the end of an exhaled breath is referred to as end-tidal CO2 (EtCO2). Studies have revealed the waveform analysis of capnography can provide early warning for prehypoxic respiratory depression in patients undergoing procedure sedation in emergency department and gastrointestinal endoscopy. Therefore, capnography can serve as a real-time measure of ventilatory status of sedative patients and the physicians could intervene before the occurrence of hypoxemia. Based on the advantage of non-invasive and real-time property of EtCO2 monitored by capnography, the investigators plan to conduct a clinical trial to evaluate if hypoxemia could be reduced by capnography of EtCO2 monitor during induction of FB sedation.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 124 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Prevention
Official Title: Capnography Monitoring the Hypoventilation During Bronchoscopic Sedation
Study Start Date : January 2015
Actual Primary Completion Date : December 2016
Actual Study Completion Date : December 2016

Arm Intervention/treatment
Experimental: A nasal-oral cannula of capnography
Start bronchoscopy when the nasal-oral capnography shows hypoventilation during bronchoscopic sedation.
Device: A nasal-oral cannula of capnography
After propofol infusion, the complete induction is defined when capnography shows hypoventilation and bronchoscope is then introduced to patients.
Other Name: End-tidal CO2

Active Comparator: Sedation scale
Start bronchoscopy when Observer Assessment of Alertness and Sedation scale (OAAS)=3~2 during bronchoscopic sedation.
Other: Observer Assessment of Alertness and Sedation scale
After propofol infusion, the complete induction is defined when OAAS is 3 to 2 (conscious sedation) and bronchoscope is then introduced to patients.
Other Name: OAAS

Primary Outcome Measures :
  1. Hypoxemia [ Time Frame: 60 minutes ]
    Oxyhemoglobin saturation less than 90% with any duration after induction to patient recovery.

Secondary Outcome Measures :
  1. Patient satisfaction [ Time Frame: 60 minutes ]
    A 10cm visual analogue scale about how the patients fell about the bronchoscopy

  2. Patient cooperation accessed by bronchoscopists [ Time Frame: 60 minutes ]
    A 10cm visual analogue scale about how the bronchoscopists fell the cooperation of patients during bronchoscopy.

  3. Induction time [ Time Frame: 10 minutes ]
    The length of time for achieving adequate sedative depth to start bronchoscopy

  4. Procedure time [ Time Frame: 30 minutes ]
    The length of time for complete bronchoscopy

  5. Propofol dosage [ Time Frame: 60 minutes ]
    the dose of propofol for induction and whole bronchoscopy

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients undergoing elective bronchoscopy and sedation

Exclusion Criteria:

  • Age less than 18 years
  • American Society of Anaesthesiologists (ASA) physical status classification IV or V
  • Mallampati score of 4
  • Severe sleep apnoea syndrome (apnoea-hypopnea index more than 40)
  • Body mass index more than 42 in males or 35 in females
  • Neurologic disorders or other conditions contributing to difficulty in assessing response
  • Forced expiratory vital capacity (FVC) less than 15 ml/kg body weight, forced expiratory volume in one second (FEV1) less than 1000 ml, or FEV1/FVC less than 35%
  • Chronic use of opioid drugs
  • Pregnancy
  • Patients with a known history of allergy to the study drugs, or to eggs, soybeans or sulfite products

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): NCT02848118

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Chung Gung Medical Fundation
Taoyuan, Taiwan, 333
Sponsors and Collaborators
Chang Gung Memorial Hospital
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Principal Investigator: Yu-Lun Lo, MD Chang Gung Medical fundation

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Responsible Party: Yu-Lun Lo, MD, Chang Gung Memorial Hospital Identifier: NCT02848118    
Other Study ID Numbers: 104-0872C
First Posted: July 28, 2016    Key Record Dates
Last Update Posted: March 9, 2017
Last Verified: March 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided
Keywords provided by Yu-Lun Lo, Chang Gung Memorial Hospital:
Additional relevant MeSH terms:
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Respiratory Insufficiency
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms