PURPOSE
The purpose of this study is to investigate the possible effects of protective surgical masks on the cardiorespiratory function of children aged 8-14 years at rest and during exercise.
METHODS
A. Population
Children aged 8-14 years (minimum height 135 cm) will be invited to participate. They will be recruited from the outpatient clinics of the Pediatric Allergy and Pediatric Endocrinology Departments of the University Hospital of Patras, Greece. Children should not suffer from conditions that are likely to affect cardiopulmonary exercise testing (CPET) outcomes, such as respiratory (asthma and chronic lung disease), cardiac (congenital heart disease, heart failure), neurologic and musculoskeletal disorders.
The parents of the children will be informed about the aims of the study and they will be asked to give written consent. The study has been approved by the local Research and Ethics Committee (Act no. 407/9.10.2020).
B. Protocol
The study will be performed at the Respiratory Functions and CPET Laboratory of the Pediatric Pulmonary Unit. Children will present to the laboratory with one of their parents.
After history taking and measurement of weight and height, baseline spirometry will follow using a Micro5000 device (Medisoft, Sorinnes, Belgium) to determine FEV1, FVC, FEV1/FVC, FEF25-75 and PEF. The study will consist of two phases:
* Phase I: No face mask. Participants will perform
1. Measurement of peak nasal inspiratory flow (nPIF) using the Micro5000 device and a specially modified nasal mask.
2. CPET using an ULTIMA CPX device (MGC Diagnostics, Saint Paul, MI, USA) with an ergometric bike (eBike, GE Healthcare, Wauwatosa, WI, USA). Participants will be asked to exercise (steady pedaling at 60 rpm) at 30% of their predicted maximum workload (Wmax) for 4 minutes, at 50% of Wmax for 2 minutes and at 70% of Wmax for 1 minute. Wmax will be calculated as 3 Watts/kg.
During CPET, oxygen saturation (SpΟ2) and heart rate (HR) will be continuously monitored using a Nonin 7500 pulse oximeter with a special ear sensor (Nonin Medical Inc, Plymouth, MN, USA). End-tidal CO2 (EtCO2) and respiratory rate (RR) will also be monitored using a Microstream device with special sampling (nasal) lines (Medtronic, Minneapolis, MN, USA).
3. Spirometry and measurement of nPIF immediately after CPET.
4. Discomfort assessment using a special scale graded from 1 to 10.
* Phase II: Face mask. Following nPIF measurement, participants will be asked to wear a standard surgical face mask. A temperature and humidity sensor (RHT03, MaxDetect Technologies, Shenzhen, China) will also be placed inside the mask on the right cheek, at nose level. Subsequently will follow:
1. Resting phase, with the participants on the ergometric bike without pedaling and breathing normally for 6 minutes. SpO2, HR, EtCO2 and RR will be monitored during the resting phase.
2. CPET at 30% of Wmax for 4 minutes, 50% of Wmax for 2 minutes and 70% of Wmax for 1 minute. SpO2, HR, EtCO2 and RR will be continuously monitored.
3. Spirometry and measurement of nPIF immediately after CPET.
4. Discomfort assessment.
Both phases will be performed on the same day with a recovery phase of 30 minutes between them. Participants will be randomized to begin with Phase I followed by Phase II or Phase II followed by Phase I.
At both phases, SpO2, HR, EtCO2 and RR (10 s average values) will be recorder at each 1 minute during CPET, and at minutes 0, 3 and 6 during the resting phase of Phase II. During Phase II, temperature and humidity will also be recorded at each 1 minute during CPET and at minutes 0, 3 and 6 during the resting phase.
The total duration of the protocol is estimated at 90 minutes per participant. The study sample will consist of 40 children stratified by age.
