Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05922020 |
| Other study ID # |
IRB-70628 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
August 8, 2023 |
| Est. completion date |
December 12, 2023 |
Study information
| Verified date |
March 2024 |
| Source |
Stanford University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
In this preliminary, crossover investigation the investigators will examine the effect of
oxygen supplementation on the recovery of breathing in the immediate post-anesthesia period.
Description:
In a pilot randomized-controlled trial (NCT04723433) the investigators found that, compared
with standard O2 supplementation, hyperoxia enhanced ventilation, as estimated by the
fraction of time at a transcutaneous PCO2 (TcPCO2) > 45 mmHg.
More specifically, patients treated with hyperoxia (O2 titrated to: SpO2 > 96%, N=10; Liberal
O2) for 90 minutes post-anesthesia, spent 61.2% of the time at TcPCO2 > 45 mmHg, compared
with 80.6% of the time in those receiving standard O2 supplementation (O2 titrated to: SpO2
between 90-94%, N=9; Conservative O2 - between-group difference of 19.4% (95% Confidence
Intervals: -18.7% to 57.6%), ANCOVA adjusted P = 0.140]. Results were consistent across the
90-min monitoring period. With an observed effect size of 0.73, it was estimated that 30
participants per group are required, to demonstrate this difference with a power of 80% at a
two-sided alpha of 5%.
In a follow-up RCT (IRB-63878, NCT05379673) in 18 patients the investigators found that over
a 90-minute window, the average percentage of time spent at TcPCO2 > 45mmHg for patients in
the Conservative O2 group (N=9) was 57.8% (52 ± 44 minutes), compared with a 45.6% (41 ± 46
minutes) for those in the Liberal O2 group (N=9), (P=0.6134; two-sided two sample t-test). In
addition, during the same period, respiratory disturbance index (RDI; events per hour) was
higher in the Conservative O2 [median (range): 23.9 (11.0-78.6)], compared with the Liberal
O2 group [19.6 (2.8-40.4), Mann-Whitney test, P=0.1615].
Due to the high variability observed in the evaluated respiratory parameters (i.e., TcPCO2
and upper airway obstruction expressed by Respiratory Disturbance Index), the researchers
believe that a crossover, rather than a randomized controlled trial, design would improve the
power and efficiency of this investigation and also provide an opportunity to characterize
better those patients who respond, and separate them from those who do not respond to
hyperoxia treatment.
This preliminary investigation will assess how ventilation during recovery from general
anesthesia is affected by conservative (Conservative O2: 90% ≤ SpO2 ≤ 94%), compared with
liberal (Liberal O2: SpO2 > 96%) O2 supplementation. Using a crossover study design, the
investigators aim to: a) assess the breathing pattern and estimate and compare the number of
apnea/hypopnea episodes between the two interventions, and b) estimate and compare the
cumulative segment of time during which the transcutaneous partial pressure of carbon dioxide
(TcPCO2) will exceed 45 mmHg, between the two interventions.
Hypothesis: Conservative O2 will be associated with more unstable and obstructed breathing
and less time spent with TcPCO2 > 45 mmHg, compared with Liberal O2 supplementation, during
recovery from anesthesia.
