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Trial registered on ANZCTR


Registration number
ACTRN12620001190998
Ethics application status
Approved
Date submitted
17/06/2020
Date registered
10/11/2020
Date last updated
3/04/2024
Date data sharing statement initially provided
10/11/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
NIGHT OWL: New prediction strategies to help test for obstructive sleep apnoea and correlate patient risk with level of care. A single centre, observational study to investigate the predictive value of procedures to test for obstructive sleep apnoea in children prior to tonsillectomy surgery.
Scientific title
Determining the predictive value of upper airway collapsibility measurements in comparison to polysomnographic procedures and screening of clinical features to test for obstructive sleep apnoea in children prior to tonsillectomy surgery.
Secondary ID [1] 301521 0
None
Universal Trial Number (UTN)
None
Trial acronym
NIGHTOWL
Linked study record
The NIGHTOWL study is a follow on study to:
OSATS study part 1 registration: ACTRN: ACTRN12615001037594
OSATS study part 2 registration: ACTRN12617001503314

Health condition
Health condition(s) or problem(s) studied:
Respiratory complications under general anaesthetic in children undergoing tonsillectomy (+/-adenoids/grommets) procedures. 317878 0
Sleep Disordered Breathing including sleep apnoea 317879 0
Condition category
Condition code
Anaesthesiology 315919 315919 0 0
Anaesthetics
Surgery 315920 315920 0 0
Other surgery
Respiratory 315921 315921 0 0
Sleep apnoea

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
1) Polysomnography (overnight sleep study) a single overnight study will be performed by an experienced sleep scientist or technician with each participant within 3 months prior to surgery.Measurements include electroencephalogram (EEG), electrooculograms (EOG), submental electromyogram (EMGgg), oronasal airflow, chest and abdominal wall motion, and arterial O2 saturation. Anterior tibial EMG will be monitored bilaterally. Cardiac rhythm will be monitored. A pulse oximeter will measure arterial oxygen saturation. Transcutaneous carbon dioxide (TcCO2) will be monitored continuously. Snoring will be recorded by a microphone suspended 1 meter above the patient. Motion of the chest wall (rib cage and abdomen) will be measured with respiratory inductive plethysmography. To monitor sleeping position and sleep behaviour, participants will be videoed throughout the night


(2) Overnight Oximetry
Blood Oxygen level (SpO2) will be measured by Nonin wrist-worn oximeter device (WristOx 3150, Nonin Medical, Plymouth, MN). The Nonin WristOx 3150 is a small, lightweight pulse oximeter designed to be worn comfortably on the patient’s wrist. On the night of the pre-operative sleep study all participants will have oximetry and polysomnography simultaneously. All children will be asked to wear the Nonin WristOx2 oximetrey watches 4 nights after the in-laboratory sleep study. The following signals will be recorded- pulse oximetry and heart rate.

(3) Activity monitoring
Participants will be asked to wear an Actigraph. Actigraphs are ambulatory devices that determine sleep-wake patterns using accelerometers. Actigraph GT9X (3.5 x 10 cm, weight 14 grams) are designed to measure and record acceleration in all direction and have been shown to provide reliable and valid measures of sleep, physical activity and sedentary time. The digitized values are summed over a user-specified interval (15 seconds for this study), resulting in a count value per 15 second epoch. All children will be asked to wear two Actigraph activity monitors on the wrist and hip for 5 consecutive days after the pre-operative sleep study. Monitors will be fitted and explanation and instructions on their use will be given to the parents at the time of consent or a time closer to the sleep study. The Actigraph will be worn 24 hours per day on the right hip and wrist via an elasticated belt and wrist strap.


(4) 3D Facial imaging
Measurement of the 3-dimensional (3D) components of the human face is a new technique which allows assessment of the skeletal and soft tissues of the face and neck. It has the ability to provide information regarding linear distances and angles. It can also provide information on facial contours and soft tissue volume. Craniofacial anatomy is recognised as an important predisposing factor in obstructive sleep apnoea (OSA) pathogenesis . Therefore, 3D facial surface measurement is an ideal tool for the assessment of the role of craniofacial structure in the development of OSA.

(5) Sleep Questionnaires
Parents will be asked to complete two sleep questionnaires to identify children with sleep disordered breathing symptoms.
Paediatric Sleep Questionnaires (PSQ)- Sleep-Disordered Breathing Subscale:
The PSQ has 22 questions in 4 domains: sleep related breathing, snoring, daytime somnolence, and behaviour.The presence/ absence of the symptom can be answered as “Yes”, “No” or “Don’t Know”. A simple 1-page PSQ symptom inventory will take around 5 minutes to complete.
STBUR (Snoring, Trouble Breathing, Un-Refreshed):
STBUR screening tool includes five questions: snore more than half of the time, snore loudly, trouble breathing, witnessed apnoea and wake up feeling un-refreshed in the morning.

(6) Upper airway collapsibility measurement
Measurement of upper airway collapsibility will be carried out at two different perioperative phases;
Just after induction of anaesthesia and prior to insertion of the airway device and any opioids (i.e. prior to the procedure starting)
At emergence just after the removal of the airway device (i.e. after the procedure has been completed)
The measurements involve the use of an anaesthetic mask and require the patient to be breathing spontaneously while anaesthesia is maintained. Pressure is continuously measured inside a facemask (pressure transducer) while airflow and phase of respiratory cycle are monitored by a pneumotachograph attached to the nasal mask (on a computer screen visible by the anaesthetist).

(7) Ambulatory Sleep study
Post-operative overnight ambulatory sleep study (Type II) (Nox A1 device, Nox Medical,
Iceland) will be performed on the night following surgery on the ward. This study will provide
information regarding the recovery profile, sleep breathing and sleep behaviour. The measurements are painless and done with simple instruments placed on the body surface. Set up will be performed by a training research team.
Intervention code [1] 317832 0
Diagnosis / Prognosis
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 324146 0
Pclose (magnitude of the pre- and/or postoperative Pclose and change in Pclose) will predict the risk of Perioperative Respiratory Adverse Events (PRAE) over the entire first postoperative night
Timepoint [1] 324146 0
Day of procedure when airway collapsibility measurements will be completed in theatre
Primary outcome [2] 324147 0
Degree of OSA severity (apnoea-hypopnoea index (AH)I, number of desaturations <92%) during the first postoperative night will be measured by an ambulatory polysomnography(Nox A1 device, Nox Medical, Iceland).
Timepoint [2] 324147 0
On the day of surgery an overnight, sleep study will be conducted on the ward to measure the degree of OSA severity (apnoa-hypopnoea index (AH)I, number of desaturations <92%)
Primary outcome [3] 324148 0
Provide descriptive data on the recovery profile including sleep behaviour on the night of a tonsillectomy (+/- adenoidectomy) procedure. The Nox device will continuously monitor the child overnight on the first postoperative night and provide information regarding composite of the recovery profile, sleep breathing and sleep behaviour. This will be measured by data analytics from Nox A1.
Timepoint [3] 324148 0
Day of procedure when airway collapsibility measurements will be completed in theatre and for the first night postoperative while in the hospital though continuous monitoring
Secondary outcome [1] 383868 0
Successful completion of pre-operative clinical questionnaires
Timepoint [1] 383868 0
Pre-operatively within 3 months of surgery
Secondary outcome [2] 383869 0
Successful completion of a pre-operative lab based PSG (sleep study) for all participants determined through sleep study video monitoring, electroencephalogram (EEG), electrooculograms (EOG), submental electromyogram (EMGgg), oronasal airflow, chest and abdominal wall motion, arterial O2 saturation, anterior tibial EMG, cardiac rhythm, arterial oxygen saturation, transcutaneous carbon dioxide (TcCO2) monitoring and respiratory inductive plethysmography.
Timepoint [2] 383869 0
Pre-operatively within 3 months of surgery
Secondary outcome [3] 383870 0
Pre-operative respiratory risk factors will be measured using a study-specific questionnaire. The respiratory risk factors include asking the following questions:
Cold or fluu in last 2 weeks
3 or more wheezing event s in the past year
Wheezing at exercise in the past year
Previous history of asthma
Nocturnal cough in the pas t year
Presence of hay fever or eczema
Family history (2 or more parents/ siblings/grandparents) with asthma, eczema or hayfever
Exposure to passive smoke.
Timepoint [3] 383870 0
Day of procedure
Secondary outcome [4] 383871 0
Pre-operative 3d photographic images will be used to identify structural risk factors associated with OSA,
Timepoint [4] 383871 0
Day of pre-operative sleep study
Secondary outcome [5] 383872 0
Measures of sleep and wakefulness will be measured using data analytics from the Actigraphy and oximetry devices
Timepoint [5] 383872 0
5 days of activity monitoring pre operatively being completed in the 3 months
prior to the day of procedure and 5 days of monitoring after the first post operative night.

Eligibility
Key inclusion criteria
Inclusion criteria
Children aged 1 to 8 years of age
Undergoing elective surgery under general anaesthetic for tonsillectomy (+/- adenoids, myringotomy, insertion of grommets and/or cautery of inferior turbinates)
Minimum age
1 Years
Maximum age
8 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Exclusion criteria
Need for premedication with midazolam
Contraindication for the use of sevoflurane
Inability to give informed consent
Children with known cardiopulmonary disease
Significant medical disease or condition that is likely to interfere with the protocol or might be confounded by the protocol.
Born less than 32 weeks of gestational age

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
Perioperative respiratory complications occur in 30 to 50% of children undergoing tonsillectomy (+/- adenoidectomy) with a number of patients experiencing multiple events. Poisson or negative binomial regression methods will be used to analyse the relationship between the critical pressure at which the airway tends to collapse (Pclose) and the rate of occurrence of PRAE.
Linear regression will be used to analyse the association of pre-operative Pclose measurements with the severity of OSA. The presence and severity of childhood OSA is defined using the obstructive apnoea-hypopnoea index (OAHI). The severity of OSA is defined as mild if an OAHI is between 1 and 5 (events/h), moderate if the OAHI is between 5 and 10 events/h and severe if the OAHI is greater than 10 events/h. We will also examine the Paediatric Sleep Questionnaire- Sleep Disordered Breathing Subscale and Snoring, Trouble Breathing, Un-Refreshed (STBUYR) Questionnaire as predictors of OSA severity, and compare the r-squared (proportion of variation explained by the model) and effect sizes between these models to gain an understanding of how Pclose compares to these clinical tools in terms of OSA severity predictive power.
We will also assess the intra-person variability of Pclose measurements at each time point. This will allow us to understand the degree of reliability that Pclose measurements can provide in terms of predicting the severity of OSA. A comparison of the standard deviation to the mean value of the measurements will be carried out for this purpose using the coefficient of variation (relative standard deviation).
Additionally, the sensitivity and specificity of this proposed technique will be extracted from receiver operator characteristic (ROC) curves plotted (Pclose vs occurrence of PRAE/severity of OSA obtained from PSG).
All data will be reported according to the STARD 2015 guidelines.

Sample size
This study is an exploratory study assessing the capacity of the Pclose (magnitude of the pre- and/or postoperative Pclose and change in Pclose) to predict the risk of Perioperative Respiratory Adverse Events (PRAE) over the entire first postoperative night. It looks to identify if a change in Pclose (with surgery) correlates with the degree of OSA severity (AHI, number of desaturations <92%) during the first postoperative night as measured by an ambulatory PSG (Nox A1 device, Nox Medical, Iceland). Our preliminary analysis demonstrates a difference in Pclose between children presenting with PRAE (n=18, median Pclose (IQR) = -4.9 cmH2O (-7.0 -0.9)) and those who did not (n=7, median Pclose (IQR) = -10.3 cmH2O (-12.5 -1.3)).
Sample size calculations were performed in R, based on linear statistical model with covariates including prior measurement of response variable, age, BMI, sex and OSAT status. For 95% power, using a conservative value of 0.5 for model correlation coefficient, a sample of 60 was obtained. Within our sample size, we need to account for invalid and missing data due to clinical/technical reasons and/or voluntary withdrawal. Thus, we believe n=60 will provide us with sufficient information on the comparison of these two variables for an appropriate and more refined sample size calculation for future research on this topic.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
7/12/2020
Actual
25/02/2021
Date of last participant enrolment
Anticipated
31/03/2023
Actual
3/08/2023
Date of last data collection
Anticipated
31/05/2023
Actual
11/10/2023
Sample size
Target
60
Accrual to date
Final
62
Recruitment in Australia
Recruitment state(s)
WA
Recruitment hospital [1] 16922 0
Perth Children's Hospital - Nedlands
Recruitment postcode(s) [1] 30577 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 305963 0
Hospital
Name [1] 305963 0
Perth Children's Hospital
Country [1] 305963 0
Australia
Funding source category [2] 305979 0
Charities/Societies/Foundations
Name [2] 305979 0
Perth Children'S Hospital Foundation
Country [2] 305979 0
Australia
Primary sponsor type
Hospital
Name
Perth Children's Hospital
Address
Department of Anaesthesia and Pain Medicine
Perth Children's Hospital
15 Hospital Avenue
Nedlands
WA 6009
Country
Australia
Secondary sponsor category [1] 306420 0
None
Name [1] 306420 0
Address [1] 306420 0
Country [1] 306420 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 306203 0
Child and Adolescent Health Services Ethics Committee
Ethics committee address [1] 306203 0
Level 5
Perth C hildren's Hospital
15 Hospital Avenue
Nedlands
WA 6009
Ethics committee country [1] 306203 0
Australia
Date submitted for ethics approval [1] 306203 0
18/11/2019
Approval date [1] 306203 0
03/02/2020
Ethics approval number [1] 306203 0
RGS0000003677
Ethics committee name [2] 306219 0
Human Ethics, The University of Western Australia
Ethics committee address [2] 306219 0
The University of Western Australia
M459
35 Stirling Highway
Crawley
WA 6009
Ethics committee country [2] 306219 0
Australia
Date submitted for ethics approval [2] 306219 0
14/02/2020
Approval date [2] 306219 0
17/02/2020
Ethics approval number [2] 306219 0
RA/4/20/6035

Summary
Brief summary
Tonsillectomy is one of the most common procedures in childhood in Australia. Despite this, the incidence of minor bleeding, pain, nausea and vomiting and respiratory complications are very common (overall up to 70% of children). This study will improve the peri-operative evaluation of paediatric Obstructive Sleep Apnoea (OSA) and help to identify patients who can have tonsillectomy (+/- adenoidectomy) as a day case. This is a single centre, explorative observational study.
Trial website
None
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 103078 0
Prof Britta Regli-von Ungern-Sternberg
Address 103078 0
Perth Children's Hospital
15 Hospital Avenue
Nedlands
WA 6009
Country 103078 0
Australia
Phone 103078 0
+61 864564805
Fax 103078 0
Email 103078 0
[email protected]
Contact person for public queries
Name 103079 0
Britta Regli-von Ungern-Sternberg
Address 103079 0
Perth Children's Hospital
15 Hospital Avenue
Nedlands
WA 6009
Country 103079 0
Australia
Phone 103079 0
+61 864564805
Fax 103079 0
Email 103079 0
[email protected]
Contact person for scientific queries
Name 103080 0
Britta Regli-von Ungern-Sternberg
Address 103080 0
Perth Children's Hospital
15 Hospital Avenue
Nedlands
WA 6009
Country 103080 0
Australia
Phone 103080 0
+61 864564805
Fax 103080 0
Email 103080 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.