Effectiveness of preoxygenation with positive airway pressure in non-obese healthy patient: a comparison of the supine and 25° head up position

Abstract Background Though conventional preoxygenation provides extended safe apnoeic period during endotracheal intubation, it is associated with atelectasis of lungs immediately after induction. Therefore, alternatives such as positive airway pressure and head-up tilt during preoxygenation have been explored but uniform recommendations have not yet been made. In the present study we aimed to find out the effect of combination of 5 cmH2O CPAP and 25° head up position during preoxygenation on non-hypoxic apnea period. Methods In this randomized controlled trial, 60 non-obese healthy adult patients were randomly divided into three groups; Group C receiving preoxygenation in conventional technique, Group S receiving preoxygenation in supine position 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 administered vecuronium to maintain neuromuscular blockade and midazolam to prevent awareness. Post-induction, patients in all groups 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%). Results The duration of non-hypoxic apnea period was longer (p<0.05) in Group H patients (405.90±106.69 s) as compared to the Group C (296.90±99.01 s) and Group S (319.65±71.54 s). Although the duration of non-hypoxic apnea was clinically longer in the Group S as compared to Group C the difference was not statistically significant. There were no remarkable adverse events observed in any group. Conclusion Preoxygenation in 25° head-up position with 5 cmH2O CPAP significantly prolongs non-hypoxic apnea period in non-obese healthy adults compared to supine position, with or without 5 cmH2O CPAP.

Download Full-text

Effect of Positive Airway Pressure During Preoxygenation on Safe Apnea Period: a comparison of the supine and 25° head up position

Kathmandu University Medical Journal ◽

10.3126/kumj.v18i2.33258 ◽

2020 ◽

Vol 18 (2) ◽

pp. 62-67

Author(s):

Y. Dhakal ◽

B. Bhattarai ◽

S. Khatiwada ◽

A. Subedi

Keyword(s):

Continuous Positive Airway Pressure ◽

Supine Position ◽

Airway Pressure ◽

Positive Airway Pressure ◽

Conventional Technique ◽

Head Up Tilt ◽

The Difference ◽

Post Intubation ◽

Induction Of Anaesthesia ◽

Safe Apnea Period

Background Preoxygenation is performed before induction of anaesthesia which increases oxygen reserve and provides delayed onset of hypoxia during period of apnea. Several techniques such as positive airway pressure and head-up tilt during preoxygenation have shown to prolong safe apnea period compared to conventional technique. However, uniform recommendations have not yet been made. Objective To find out the effect of combination of 5 cmH2O continuous positive airway pressure (CPAP) and 25° head up position during preoxygenation on safe apnea period. Method In this comparative study 60 non-obese adult patients were divided into three equal groups; Group C receiving preoxygenation in conventional technique, Group S receiving preoxygenation with 5 cmH2O continuous positive airway pressure in supine position and Group H receiving preoxygenation in 25° head-up position with 5 cmH2O continuous positive airway pressure . After 3 min of preoxygenation, intubation was performed after induction of anaesthesia with propofol, fentanyl and succinylcholine. After confirming the tracheal intubation by direct visualization, all patients were administered vecuronium to maintain neuromuscular blockade. Post-intubation, patients in all groups were left in same position with the tracheal tube exposed to atmosphere and without being ventilated till the SpO2 dropped to 92%. The primary outcome compared between the groups was the safe apnea period (time from loss of consciousness to fall of SpO2 to 92%). Result The duration of safe apnea period was longer (p < 0.05) in Group H patients (405.9 ± 106.69 s) as compared to the Group C (296.9 ± 99.01s) and Group S (319.65 ± 71.54s). Although the duration of safe apnea period was longer in the Group S as compared to Group C the difference was not statistically significant. Conclusion Preoxygenation in 25° head-up position with 5 cmH2O continuous positive airway pressure significantly prolongs safe apnea period in non-obese adults compared to supine position, with or without 5 cmH2O continuous positive airway pressure.

Download Full-text

Effect of continuous positive airway pressure therapy in patients with paroxysmal atrial fibrillation and obstructive sleep apnea: a randomized controlled trial

European Heart Journal ◽

10.1093/ehjci/ehaa946.0670 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

G.M Traaen ◽

L Aakeroy ◽

T.E Hunt ◽

B Overland ◽

C Bendz ◽

...

Keyword(s):

Quality Of Life ◽

Usual Care ◽

Airway Pressure ◽

Positive Airway Pressure ◽

Controlled Trial ◽

Funding Source ◽

Randomized Controlled ◽

Effect Of Treatment ◽

The Difference

Abstract Background There is strong evidence for an association between atrial fibrillation (AF) and sleep apnea (SA). Purpose We aimed to examine the effect of treatment with continuous positive airway pressure (CPAP) on the burden of AF. Methods After a run-in period for CPAP-tolerance, we randomly assigned 108 eligible patients between 18–75 years, who had paroxysmal AF and moderate-to-severe obstructive SA (apnea-hypopnea index (AHI)≥15), to receive either CPAP treatment (n=54) plus usual care or usual care alone (n=54) for five months. An implanted loop recorder measured time in AF continuously. The primary endpoint was the difference in change of AF burden (% of time in AF) between CPAP treatment and usual care from baseline (one month prior to randomization) to the last three months of the intervention period. Secondary endpoints were changes in quality of life assessed by the Short Form-36 (SF-36), Epworth Sleepiness Scale (ESS), and the Functional Outcomes of Sleep Questionnaire (FOSQ). Results Mean (SD) age was 62.4 (7.7) years, BMI 29.4 (4.2) kg/m2, ESS 7.9 (3.2), and 76.1% were men. In the intervention group, the mean duration of adherence to CPAP therapy was 4.3 hours/night. During treatment mean AHI decreased from 27.6 events/hour at baseline to 2.3 events/hour during follow-up. Mean time in AF decreased from 5.0%-4.3% in the control group and from 5.6%-4.1% in the CPAP group, but the difference in change was not significant (p=0.52). Sub-analysis of those using CPAP><4 hours/night also showed no difference, neither did the quality of life questionnaires. Conclusion This is the first randomized controlled trial to assess the effect of treatment of SA on the burden of AF, and did not detect a difference between those treated with CPAP compared to usual care alone. Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Oslo University Hospital is the main funding Source. ResMed Science Center provided an unrestricted grant.

Download Full-text