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Trial registered on ANZCTR


Registration number
ACTRN12611000825954
Ethics application status
Approved
Date submitted
27/06/2011
Date registered
5/08/2011
Date last updated
5/05/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effect of continous positive airway pressure (CPAP) treatment on blood pressure control in snoring women with early pregnancy hypertension.
Scientific title
Randomised trial of continuous positive airway pressure (CPAP) treatment on blood pressure control in snoring women with early pregnancy hypertension.
Secondary ID [1] 262483 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Pregnancy Hypertension 268172 0
Obstructive Sleep Apnoea 268173 0
Condition category
Condition code
Reproductive Health and Childbirth 268302 268302 0 0
Fetal medicine and complications of pregnancy
Respiratory 268462 268462 0 0
Sleep apnoea
Cardiovascular 268463 268463 0 0
Hypertension

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Randomised treatment with CPAP. CPAP will be delivered primarily via a nasal mask, although other mask types will be tried as needed to ensure a comfortable fit and good interface with the patient. CPAP pressure will be provided using a variable pressure S8 Autoset device (ResMed) set to deliver a pressure between 4-16 cmH2O. Participants will be encouraged to wear the CPAP every time they sleep and use of CPAP will commence at randomisation and continue through to delivery day.
CPAP will be commensed as soon as possible after randomisation. The exact day they start CPAP will vary from patient to patient but will be within 2 weeks of randomisation.
Intervention code [1] 266835 0
Treatment: Devices
Comparator / control treatment
All women will undergo routine obstetric hypertensive management.
Control group
Active

Outcomes
Primary outcome [1] 269044 0
Blood pressure control and anti-hypertensive medication requirement. Blood pressure will be measured using an automated syphygomanometer to help with blinding of the measurement. All women will be seated for at least 10 minutes and have their feet resting comfortably on the floor. BP measurements will be routinely taken from the left arm. Patients need for anti-hypertensive management will be asssessed separately by obstetric medicine specialists who are blinded to the study and will make their own assessments. Anti-hypertensive medication will be prescribed following a standardised protocol based on current best practice.
Timepoint [1] 269044 0
Every 2 weeks throughout the pregnancy and also at 32 weeks gestation.
Secondary outcome [1] 276858 0
The following pregnancy related complications will be recorded as adverse pregnancy outcomes: Pre-term delivery (delivery before 37/40 gestation), perinatal death, pre-eclampsia, foetal growth restriction (based on local growth charts), and initial Apgar score of less than or equal to 7. This information is routinely collected and will be obtained from the obstetric notes.
Timepoint [1] 276858 0
End of pregnancy.

Eligibility
Key inclusion criteria
Women presenting with early hypertension in pregancy (before 20 weeks gestation) and a history of snoring.
Minimum age
18 Years
Maximum age
60 Years
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Known secondary hypertension.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Randomised code concealed in numbered envelopes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Sequence generated by biostatistician using permuted block randomisation generated from computer software (SAS 9.1)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
This study will investigate the feasibility of the concept that using different wake and sleep pressures will improve participant comfort while not negatively affecting therapy delivery. Once feasibility is confirmed, comparative studies with statistical analyses may be performed to measure the efficacy of the concept.

All participants whom undergo some treatment on the FPH bi-level PAP device will be analysed. If the investigators are able to accurately use the PSG signal to apply awake and asleep bi-level PAP to a participant using the RICON device; and secondly, using the number of breaths triggered by the device or other relevant metrics, create an algorithm capable of allowing the RICON device to automatically deliver asleep or awake bi-level PAP dependant on the state of the participant, the study will be considered a “pass”.

Based on the outcome of a small feasibility study in a similar patient population by Poyares et al showing an increase in BP in standard care group versus a reduction in the CPAP treated group, where the mean BP measurements at 32 weeks were 127 versus 118 (baseline standard deviation 2.5 and 2.4 respectively), 30 patients in each group will have greater than 90% statistical power to detect a difference between CPAP and standard care groups at 0.05 significant level. In addition, it is reported in the same study that the CPAP group has a mean methyldopa (anti-hypertensive) dose of 750mg vs. 2000mg in the standard care group. Assuming a standard deviation of 750mg and 200mg in the two groups respectively, a sample size of 30 in each group will provide 89% statistical power to detect a difference in the mean use of anti-hypertensive medications. The sample size estimation of 45 in each randomised arm also provides adequate power for a subgroup analysis for participants with AHI greater than 5 and AHI less than 5 if AHI is identified to be a potential confounder assuming approximately 1/3 of the snoring pregnant women will have AHI greater than 5.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
2/05/2011
Actual
12/05/2011
Date of last participant enrolment
Anticipated
Actual
16/05/2013
Date of last data collection
Anticipated
Actual
15/11/2013
Sample size
Target
90
Accrual to date
Final
41
Recruitment outside Australia
Country [1] 3676 0
New Zealand
State/province [1] 3676 0

Funding & Sponsors
Funding source category [1] 267308 0
Government body
Name [1] 267308 0
Health Research Council of New Zealand
Country [1] 267308 0
New Zealand
Primary sponsor type
Government body
Name
Health Research Council of New Zealand
Address
Level 3
110 Stanley Street
PO Box 5541
Auckland 1141
Country
New Zealand
Secondary sponsor category [1] 266372 0
None
Name [1] 266372 0
Address [1] 266372 0
Country [1] 266372 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 269299 0
Northern X Regional Ethics Committee
Ethics committee address [1] 269299 0
Miinistry of Health
3rd Floor, Unisys Building
650 Great South Road. Penrose
Private Bag 92522
Auckland 1061
Ethics committee country [1] 269299 0
New Zealand
Date submitted for ethics approval [1] 269299 0
Approval date [1] 269299 0
06/10/2010
Ethics approval number [1] 269299 0
NTX/10/08/085

Summary
Brief summary
A number of observational studies have demonstrated that snoring in pregnancy is associated with the development of pregnancy hypertension and its associated pregnancy complications. It is known that upper airway dimensions narrow during pregnancy and this will lead to increased airway closure resulting in snoring. Snoring is associated with obstructive sleep apnoea (OSA) which is a condition strongly linked with the development of systemic hypertension. OSA related hypertension improves on treamtent with continuous positive airway pressure (CPAP). One small trial (16 patients) suggests that CPAP may be of benefit in snoring women with pregnancy hypertension.
This is a large randomised trial to assess whether CPAP treatment can improve blood pressure control and therefore pregnancy outcomes in hypertensive pregnant women who snore.
Trial website
Trial related presentations / publications
There are currently no publications, but the intention of the investigator is to write this up during an upcoming sabbatical.
Public notes

Contacts
Principal investigator
Name 32797 0
Dr Dr Stuart Jones
Address 32797 0
Middlemore Hospital Private Bag 93311 Otahuhu Auckland 1640
Country 32797 0
New Zealand
Phone 32797 0
+64 9 2760000
Fax 32797 0
Email 32797 0
[email protected]
Contact person for public queries
Name 16044 0
Stuart Jones
Address 16044 0
Middlemore Hospital
Private Bag 93311
Otahuhu
Auckland 1640
Country 16044 0
New Zealand
Phone 16044 0
+64 9 2760000 ext 2883
Fax 16044 0
Email 16044 0
[email protected]
Contact person for scientific queries
Name 6972 0
Stuart Jones
Address 6972 0
Middlemore Hospital
Private Bag 93311
Otahuhu
Auckland 1640
Country 6972 0
New Zealand
Phone 6972 0
+64 9 2760000 ext 2883
Fax 6972 0
Email 6972 0
[email protected]

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No Supporting Document Provided



Results publications and other study-related documents

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