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Trial registered on ANZCTR


Registration number
ACTRN12622000776707
Ethics application status
Approved
Date submitted
11/05/2022
Date registered
31/05/2022
Date last updated
15/09/2024
Date data sharing statement initially provided
31/05/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
Feasibility and efficacy of using lung measurements to predict complications during surgery for young children with and without respiratory symptoms.
Scientific title
PUFFIN: Feasibility and efficacy of using peak cough flow to predict respiratory adverse events in children undergoing general anaesthesia: a novel application
Secondary ID [1] 306859 0
PUFFIN
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Perioperative Respiratory Adverse Events 326217 0
Children undergoing general anaesthesia 326355 0
Condition category
Condition code
Anaesthesiology 323518 323518 0 0
Anaesthetics
Respiratory 323519 323519 0 0
Other respiratory disorders / diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
All participants will be recruited on the day of surgery, once informed consent and assent is gained by the research team member (research officers, research assistants) the participant’s height and weight will be measured, if a participant is unable to stand an ulna length measurement will be used to estimate standing height. The participant will perform baseline peak cough flow (PCF) and Spirometry as per international guidelines and Perth Children’s Hospital (PCH) respiratory laboratory procedures. The order of tests will be randomised to prevent possible fatigue concerns. Parentally reported respiratory history and medication use will be recorded.
The tests will be completed by trained research team members and are expected to take 20-30 minutes in total. The testing will occur on the day of surgery prior to the patient being brought to theatre.

Peak Cough Flow
• The participant will be sitting, preferably with feet on the floor, if this is not possible the participant will sit as upright as possible, and any change in position will be recorded.
• The participant will place a filtered mouthpiece between their teeth and seal lips tightly, the research staff member will instruct them to take a full inspiration and then perform a single fast cough as hard as possible.
• Measurements will be repeated until at least 3 acceptable measurements are performed that are within 0.67L/s of each other. A maximum of 8 trials will be performed.
• Reported variables with be PCF (L/s), the absolute value and the percent predicted value will be reported.

Spirometry
• Spirometry will be performed to the international standards. At least 3 technically acceptable measurements will be performed with the best FEV1 and FVC measurements being within 0.15L of each other. A maximum of 8 trials will be performed.
• 3 acceptable and repeatable inspiratory measurements will also be recorded as per international guidelines. Inspiratory loop shape will be assessed by 2 experienced research staff members (CO, MO) to identify any abnormalities of the flow value loop shape.
• Reported variables will be absolute and z score values for FEV1, FVC, FEV1/FVC, FIF50/FEF50. The shape of the flow volume loops will be consensus scored with a binary normal/abnormal scoring.
Intervention code [1] 323520 0
Early detection / Screening
Intervention code [2] 323608 0
Diagnosis / Prognosis
Comparator / control treatment
The control group will consist of children with no respiratory symptoms; and the affected group will consist of children who have respiratory symptoms.
Control group
Active

Outcomes
Primary outcome [1] 331274 0
Overall occurrence of Perioperative Respiratory Adverse Events (PRAE).

PRAEs are defined as any one of the following and are assessed by direct clinical observation and/or examination by a nurse or anaesthetist:
-Oxygen saturation <92% determined using pulse oximetry,
-Bronchospasm
-Laryngospasm
-Severe Coughing (for more than 10 seconds)
-Airway Obstruction
-Postoperative stridor
Timepoint [1] 331274 0
PRAE Measured from the induction of anaesthesia to discharge from the post anaesthesia care unit (PACU).
Primary outcome [2] 331484 0
Overall occurrence of Perioperative Respiratory Adverse Events (PRAE) in patients with and without respiratory symptoms.

PRAEs are defined as any one of the following and are assessed by direct clinical observation and/or examination by a nurse or anaesthetist:
-Oxygen saturation <92% determined using pulse oximetry,
-Bronchospasm
-Laryngospasm
-Severe Coughing (for more than 10 seconds)
-Airway Obstruction
-Postoperative stridor
Timepoint [2] 331484 0
PRAE Measured from the induction of anaesthesia to discharge from the post anaesthesia care unit (PACU).
Secondary outcome [1] 409403 0
Peak cough flow and spirometry measurements will be measured using Easy-on PC Spirometer device. All standard spirometry values including FEV1, FVC, FEV1/FVC, FIF50/FEF50 will be recorded.
Timepoint [1] 409403 0
Pre-operatively
Secondary outcome [2] 409747 0
The feasibility of the peak cough flow assessment during the preoperative assessment as measured by the percentage of successful tests completed.
This will be determined by review of the study database.
Timepoint [2] 409747 0
Upon completion of the study

Eligibility
Key inclusion criteria
Children undergoing elective surgery under general anaesthetic
• Male or female aged between 5 and 10 years
• Control group: Children without respiratory symptoms defined as below
• Respiratory Symptoms group: Children with respiratory symptoms including:
o Recent Upper respiratory Tract infection (<2wks)
o Nocturnal cough
o >2 bouts of wheeze in the previous 12 months
o Current doctor diagnosis of asthma
o Wheeze or cough on exertion in the previous 3 months.
Minimum age
5 Years
Maximum age
10 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Children receiving midazolam as a premedication before surgery
Children who have not performed the PCF measurement prior to receiving a premedication of clonidine or dexmedetomidine
Children with a known difficult airway.
Children with a known significant cardiac disease:
o Uncorrected congenital heart disease
o Primary pulmonary hypertension
o Cardiac malformations/tumours
Inability to perform the required manoeuvre
History of syncope related to forced expiration/cough
Haemoptysis of unknown origin; the sniff nasal inspiratory pressures and peak cough flow manoeuvres may aggravate the underlying condition
Pneumothorax. Less than 1 week since successful treatment
Unstable cardiovascular status, recent myocardial infarction, or pulmonary embolism; Thoracic, abdominal, or cerebral aneurysms
Recent eye surgery within 1 week
Sinus or middle ear surgery or infection post 1 week
Thoracic or abdominal surgical procedures within 4 weeks.
Non English-speaking families

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
Both groups will undergo the same tests, however one group will have respiratory symptoms (e.g. recent upper respiratory tract infection, nocturnal cough, wheeze, asthma, wheeze/cough on exertion) and the other will have no respiratory symptoms. However, the order of tests will be randomised to prevent possible fatigue concerns.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Participants will be categorised as having Perioperative respiratory adverse events (PRAE) or not experiencing PRAE.
The primary outcome is PRAE, measured from induction of anaesthesia to discharge from PACU. The effect of the PCF and Spirometry measurements on PRAE will be assessed by fitting a binomial log-linear model with number of PRAE as the response. Covariates entered into the model will include patient demographics (e.g. age, weight, height, BMI, sex), respiratory risk factors, and clinical characteristics (e.g. surgery type, duration of anaesthesia, choice of airway device, medications). The control group will consist of children with no respiratory symptoms; and the affected group will consist of children who have respiratory symptoms. The order (1 or 2) of PCF and spirometry measurements will also be entered as a covariate. If the PRAE counts are dominated by zeros, then a zero-inflated Poisson model will be considered. Large amounts of missing data are not expected, since the data collection will be performed by an experienced research team and supervised by an experienced multi-disciplinary clinical team; for this reason, primary analysis will be performed on available data with no imputation. In the event of a high proportion of missing data, imputation using a standard technique will be considered. All analysis will be performed in the R statistical environment.

Sample Size
This study is the first of its kind, so there is no previous data available to base a sample size calculation on. This is a pilot study, and the calculations for sample size and power are therefore simply to estimate a large enough sample size for reasonable power. We assume that a 25% rate of PRAE corresponds to the mean PCF reading. Then further assuming an odds ratio of 1.5 for PRAE for a one standard deviation increase in PCF reading, the power for a sample size of 200 is 80%. We will therefore include 200 children, 100 with respiratory symptoms and 100 without respiratory symptoms.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
27/06/2022
Actual
22/06/2022
Date of last participant enrolment
Anticipated
24/06/2024
Actual
9/05/2023
Date of last data collection
Anticipated
28/06/2024
Actual
10/05/2023
Sample size
Target
200
Accrual to date
Final
200
Recruitment in Australia
Recruitment state(s)
WA
Recruitment hospital [1] 22321 0
Perth Children's Hospital - Nedlands
Recruitment postcode(s) [1] 37482 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 311180 0
Hospital
Name [1] 311180 0
Perth Children's Hospital
Country [1] 311180 0
Australia
Funding source category [2] 311372 0
Government body
Name [2] 311372 0
NHMRC
Country [2] 311372 0
Australia
Funding source category [3] 317412 0
Charities/Societies/Foundations
Name [3] 317412 0
Perth Children's Hospital Foundation
Country [3] 317412 0
Australia
Primary sponsor type
Hospital
Name
Perth Children's Hospital
Address
Perth Children's Hospital
15 Hospital Avenue
Nedlands
WA 6009
Country
Australia
Secondary sponsor category [1] 312540 0
None
Name [1] 312540 0
Address [1] 312540 0
Country [1] 312540 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 310711 0
Child and Adolescent Health Service Human Research Ethics Committee
Ethics committee address [1] 310711 0
Child and Adolescent Health Service Human Research Ethics Committee
15 Hospital Avenue
Nedlands
Western Australia 6009
Ethics committee country [1] 310711 0
Australia
Date submitted for ethics approval [1] 310711 0
14/04/2022
Approval date [1] 310711 0
19/05/2022
Ethics approval number [1] 310711 0
Ethics approval number is RGS0000005393

Summary
Brief summary
Perioperative respiratory adverse events (PRAE) pose a significant risk in paediatric anaesthesia, with the incidence of PRAE being reported between 15 and 50 %. Accurate detection of those at risk for developing PRAE is vital to enable tailoring of their perioperative management. Traditionally, risk of PRAE is assessed using the patient’s past medical history, family medical history and physical examination. However, given the multifactorial nature of the risk of PRAE and children with complex medical backgrounds such as chronic lung disease, obstructive sleep apnoea or obesity, patients may benefit from additional objective preoperative pulmonary function tests.
Recently our group published an educational review identifying the clinical utility of preoperative pulmonary function testing in paediatrics which identified that there is little evidence to support the routine use of lung function in preoperative assessment. However, we noted that the measurement of Peak Cough Flow (PCF) is predictive of the need for respiratory support or cough support following surgery suggesting that a higher PCF may reduce the incidence of PRAE; thus far there is no evidence in the role of PCF in preoperative assessment, however this simple, non-invasive and portable test may help identify high-risk subjects.

We propose a prospective cross-sectional interventional study to assess if Peak Cough Flow and spirometry in children with and without respiratory symptoms aged 5-10 years is clinically associated with an increased risk of developing PRAE. Monitoring and recording of PRAE (laryngospasm – closure of the vocal cords, bronchospasm – narrowing of the airways, severe and persistent coughing, airway obstruction, oxygen desaturation (<95%) and postoperative stridor-squeaky noises when breathing) will occur throughout the procedure and in the post anaesthesia care unit (PACU). We hypothesise that children with a higher percent of predicted PCF will be at a reduced risk for developing PRAE.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 118602 0
Prof Britta Regli-von Ungern-Sternberg
Address 118602 0
Perth Children's Hospital
Department of Anaesthesia and Pain Medicine
15 Hospital Avenue
Nedlands
WA 6009
Country 118602 0
Australia
Phone 118602 0
+61864564805
Fax 118602 0
Email 118602 0
[email protected]
Contact person for public queries
Name 118603 0
Britta Regli-von Ungern-Sternberg
Address 118603 0
Perth Children's Hospital
Department of Anaesthesia and Pain Medicine
15 Hospital Avenue
Nedlands
WA 6009
Country 118603 0
Australia
Phone 118603 0
+61864564805
Fax 118603 0
Email 118603 0
[email protected]
Contact person for scientific queries
Name 118604 0
Britta Regli-von Ungern-Sternberg
Address 118604 0
Perth Children's Hospital
Department of Anaesthesia and Pain Medicine
15 Hospital Avenue
Nedlands
WA 6009
Country 118604 0
Australia
Phone 118604 0
+61864564805
Fax 118604 0
Email 118604 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.