Capnography Monitoring in the Bronchoscopic Sedation

Not Applicable

Completed

• Conditions: Hypoventilation
• Interventions: Device: A nasal-oral cannula of capnography; Other: Observer Assessment of Alertness and Sedation scale

• Registration Number: NCT02848118
• Lead Sponsor: 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.

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.

Study Timeline

• Study Start: 2015-01
• Study First Submitted: 2015-03-18
• Study First Submitted QC: 2016-07-25
• Study First Posted: 2016-07-28
• Primary Completion: 2016-12
• Study Completion: 2016-12
• Status Verified: 2017-03
• Last Update Submitted: 2017-03-08
• Last Update Posted: 2017-03-09

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 124

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
A nasal-oral cannula of capnography	A nasal-oral cannula of capnography	Start bronchoscopy when the nasal-oral capnography shows hypoventilation during bronchoscopic sedation.
Sedation scale	Observer Assessment of Alertness and Sedation scale	Start bronchoscopy when Observer Assessment of Alertness and Sedation scale (OAAS)=3\~2 during bronchoscopic sedation.

Primary Outcome Measures

Name	Time	Method
Hypoxemia	60 minutes	Oxyhemoglobin saturation less than 90% with any duration after induction to patient recovery.

Secondary Outcome Measures

Name	Time	Method
Propofol dosage	60 minutes	the dose of propofol for induction and whole bronchoscopy
Patient cooperation accessed by bronchoscopists	60 minutes	A 10cm visual analogue scale about how the bronchoscopists fell the cooperation of patients during bronchoscopy.
Patient satisfaction	60 minutes	A 10cm visual analogue scale about how the patients fell about the bronchoscopy
Induction time	10 minutes	The length of time for achieving adequate sedative depth to start bronchoscopy
Procedure time	30 minutes	The length of time for complete bronchoscopy

Trial Locations

Locations (1)

Chung Gung Medical Fundation; 🇨🇳 Taoyuan, Taiwan