Effectiveness of Preoxygenation With Positive Airway Pressure: a Comparison of the Supine and 25° Head up Position

Not Applicable

Completed

• Conditions: Intubation;Difficult
• Interventions: Other: 5 cmH2O CPAP; Other: head-up position

• Registration Number: NCT03861949
• Lead Sponsor: B.P. Koirala Institute of Health Sciences

Brief Summary

Several techniques such as positive airway pressure and head-up tilt during preoxygenation have shown to prolong non-hypoxic apnea period compared to conventional technique. However, uniform recommendations have not yet been made. Therefore, in the present study the investigators attempted to find out the effect of combination of 5 cmH2O CPAP and 25° head up position during preoxygenation.

Detailed Description

In this study 60 non-obese healthy adult patients were divided into three groups; Group C receiving preoxygenation in conventional technique, Group S receiving preoxygenation with 5 cmH2O CPAP and Group H receiving preoxygenation in 25° head-up position with 5 cmH2O CPAP. After 3 min of preoxygenation, anesthesia was induced and trachea intubated. After confirming the tracheal intubation by direct visualization, all patients were left apneic in supine position with the tracheal tube exposed to atmosphere till the SpO2 dropped to 92%. The primary outcome compared between the groups was the non-hypoxic apnoeic period (time to fall SpO2 to 92%).

Study Timeline

• Study Start: 2014-06-15
• Primary Completion: 2015-06-15
• Study Completion: 2015-06-15
• Status Verified: 2019-03
• Study First Submitted: 2019-03-01
• Study First Submitted QC: 2019-03-04
• Last Update Submitted: 2019-03-04
• Study First Posted: 2019-03-05
• Last Update Posted: 2019-03-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• adult patients of ASA physical status I and II undergoing surgery under general anaesthesia

Exclusion Criteria

• anticipated difficult mask ventilation/ intubation
• individuals with significant cardiorespiratory or cerebrovascular disease
• pregnant ladies
• patient with history of epilepsy
• body mass index >25 kg/m2
• hemoglobin <8 gm/dL
• patients who were non-ambulant for >24 h, having SpO2 < 97% while breathing in room air
• phobia to facemask.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Positive-pressure	5 cmH2O CPAP	preoxygenation done with 5 cmH2O CPAP (continuous positive airway pressure) in supine position with 100% oxygen
Head-up	5 cmH2O CPAP	preoxygenation done in 25 degree head-up position with 5 cmH2O CPAP with 100% oxygen
Head-up	head-up position	preoxygenation done in 25 degree head-up position with 5 cmH2O CPAP with 100% oxygen

Primary Outcome Measures

Name	Time	Method
non-hypoxic apnoeic period (time to fall SpO2 to 92%)	2 hours	After 3 min of preoxygenation, anesthesia was induced and trachea intubated. After confirming the tracheal intubation by direct visualization, all patients were left apneic in supine position with the tracheal tube exposed to atmosphere till the SpO2 dropped to 92%.

Secondary Outcome Measures

Name	Time	Method
Comparison of PaCO2 at different time points	2 hours	Arterial blood gas analysis was done and the PaCO2 at the start of preoxygenation, after preoxygenation and at desaturation (SpO2= 92%) were compared.
Comparison of PaO2 at different time points	2 hours	Arterial blood gas analysis was done and the PaO2 at the start of preoxygenation, after preoxygenation and at desaturation (SpO2= 92%) were compared.
Comparison of pH at different time points	2 hours	Arterial blood gas analysis was done and the pH at the start of preoxygenation, after preoxygenation and at desaturation (SpO2= 92%) were compared.