None listed
Conditions
Brief summary
This is a single arm interventional study investigating the effect of short duration high flow nasal oxygen on blood pressure in pregnant people with a hypertensive disorder of pregnancy. Our hypothesis is that this therapy will either lower or not significantly alter systolic and diastolic blood pressure levels in this population. We are also collecting important consumer feedback data around therapy comfort. These findings are key feasibility challenges if larger trials examining high flow nasal oxygen during sleep in pregnant people are to be considered.
Interventions
Intervention: High flow nasal air for 10 minutes.
High flow humidified nasal oxygen (HFNO) will be applied via the Airvo 2 (Fisher & Paykel, New Zealand) machine using Optiflow (Opt944) nasal cannulae. It will be commenced at a flow of 30 litres/min and an inspired fraction of oxygen of 21% (i.e. room air). After 30 seconds, the flow rate will then be increased to 50 litres/min. The flow rate will be decreased step-wise by 10 litres/min (i.e 50 to 40 to 30 litres/min) if the participant compla
Intervention: High flow nasal air for 10 minutes. High flow humidified nasal oxygen (HFNO) will be applied via the Airvo 2 (Fisher & Paykel, New Zealand) machine using Optiflow (Opt944) nasal cannulae. It will be commenced at a flow of 30 litres/min and an inspired fraction of oxygen of 21% (i.e. room air). After 30 seconds, the flow rate will then be increased to 50 litres/min. The flow rate will be decreased step-wise by 10 litres/min (i.e 50 to 40 to 30 litres/min) if the participant complains of discomfort to a minimum of 30 litres/min after which the study protocol will be abandoned. Flow rate reduction will occur (if required) after the participant is allowed 30 seconds at that flow rate level. Commencement and titration will be performed by principal investigator (specialist anaesthetist) who will be present throughout the protocol to also monitor adherence. After ten minutes of HFNO, three blood pressure measurements will be recorded, each after 15 seconds of the previous. The average systolic, diastolic and mean blood pressure values will be calculated. Post-protocol fetal heart rate measurement will occur at the earliest practical time point after maternal vital signs are recorded.
Sponsors
Patrick Tan - Royal Women's Hospital
Study design
Allocation
Non-randomised trial
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Pregnant, obstetric diagnosis of new onset hypertensive disorder of pregnancy (including gestational hypertension, preeclampsia with or without severe features, hypertension for investigation), more than or equal to 20 weeks gestation Definition New onset hypertension will be defined as a pregnant patient with new onset hypertension after 20 weeks gestation. Preeclampsia will be defined as new onset sustained hypertension (systolic blood pressure more than or equal to 140 mmHg and /or diastolic blood pressure more than or equal to 90 mmHg), on two occasions at least four hours apart, with evidence of organ dysfunction, commencing after 20 weeks gestation and resolving within three months of delivery. Preeclampsia will be subdivided into preeclampsia without severe features and preeclampsia with severe features. Gestational hypertension will be defined as hypertension (systolic blood pressure more than or equal to 140 mmHg and /or diastolic blood pressure more than or equal to 90 mmHg) without any associated organ dysfunction. If a patient has new onset hypertension that does not meet the definition of preeclampsia or gestational hypertension their diagnosis will be recorded and will be placed in an “other” category
Exclusion criteria
Significant nasal pathology, acutely unwell with non-hypertension related cause, recent antihypertensive medication use (not within: 30 minutes of oral or IV labetalol, 60 minutes of oral nifedipine, no exclusion duration for methyldopa), not in labour
Outcome results
None listed