None listed
Conditions
Brief summary
The OASIS project is a single-centred,randomised, prospective study of 85 children. Lung mechanics will be assessed using continuous forced oscillation technique (FOT). The aims are, in children undergoing general anaesthesia, to compare the effect on forced oscillations mechanics of: 1) two different recruitment strategies: repeated inflations vs. one sustained inflation to a high-pressure level, 2) administering them through a laryngeal mask vs a cuffed tracheal tube. We hypothesise that: (1) One sustained inflation is more effective than multiple manual breaths with high levels of inspiratory and expiratory pressure in recruiting the lung (2) Both recruitment strategies (sustained inflation or multiple manual breaths) are less effective when applied via laryngeal mask compared with an endotracheal tube. The results of this study will help paediatric anaesthetists to formulate new evidence-based guidelines and policies to optimize the ventilation strategy in children undergoing general anaesthesia. Additionally, successful implementation of continuous forced oscillation technique (FOT) measurements (assessment of respiratory mechanics) in the setting of different airway devices has the potential to change routine clinical practice by allowing anaesthetists to adapt ventilation to rapid changes in mechanics during anaesthesia which are particularly pronounced in young children.
Interventions
Intervention materials:
This study involves the use of a continuous FOT (forced oscilliation technique system) to measure lung mechanics in children receiving one of four inflation techniques:
1. Sustained inflation via a Laryngeal mask airway device (LMA)
2. Repeated inflations via an LMA
3. Sustained inflation via tracheal tube (TT)
4. Repeated inflations via TT
The type of airway device will be determined by the attending anaesthetist regardless of the study. Manual breaths will be from the b
Intervention materials: This study involves the use of a continuous FOT (forced oscilliation technique system) to measure lung mechanics in children receiving one of four inflation techniques: 1. Sustained inflation via a Laryngeal mask airway device (LMA) 2. Repeated inflations via an LMA 3. Sustained inflation via tracheal tube (TT) 4. Repeated inflations via TT The type of airway device will be determined by the attending anaesthetist regardless of the study. Manual breaths will be from the bag and mask and sustained inflation will be from the machine. Procedures used: Once the interface is in place and ventilation has started, children will be randomised to receive either 20 slow manual breaths with PIP=40cmH20 and PEEP = 15 cmH20 pr one sustained manual inflation of 40 cmH20 for 20 seconds. Lung mechanics will be assessed using a continuous FOT system. Who will deliver the intervention: the intervention will be delivered by the attending paediatric anaesthetist Mode of delivery: in theatre Number of times: once Location: Perth Children's Hospital surgical theatres Lung mechanics will be assessed using FOT. Measurements will be carried out following the international guidelines and recommendations set by the American Thoracic Society and the European Respiratory Society. Low amplitude sinusoidal pressure oscillations (2 cmH2O peak-to-peak) at 5 Hz are generated by a loudspeaker connected to the inspiratory line of the mechanical ventilator and applied at the inlet of the tracheal tube. The rear of the loudspeaker is enclosed in a chamber and connected to the inspiratory outlet of the ventilator to equilibrate the positive pressures on both sides of the loudspeaker membrane. Pressure and flow are measured at the airway opening using a pressure transducer and a mesh-type heated pneumotachograph connected with a differential pressure transducer. Signals are sampled at 200 Hz and exported on a personal computer for offline analysis. FOT Measurements will be performed following the induction of anaesthesia prior to the start of surgery before and after the randomised recruitment manoeuvre as well as at the end of surgery prior to emergence of anaesthesia. Each measurement will take 1 to 2 minutes.
Sponsors
Perth Children's Hospital
Study design
Allocation
Randomised controlled trial
Intervention model
Other
Primary purpose
Diagnosis
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
2 Years to 16 Years
Healthy volunteers
No
Inclusion criteria
Children undergoing surgery with general anaesthesia through either laryngeal mask or tracheal tube.
Exclusion criteria
Children with a known difficult airway or thoracic malformation Children with a known major lung and/or cardiopulmonary disease: · Uncorrected congenital heart disease · Primary/secondary pulmonary hypertension · Cardiac/thoracic malformations/tumours · Structural lung changes · Uncontrolled asthma · Cystic Fibrosis The above list is a non-exhaustive list. Any other less common cardiopulmonary conditions will be assessed by the anaesthetist in charge and accounted for in the exclusion criteria list.
Outcome results
None listed