Evaluation of Atelectasis Formation With Electrical Impedance Tomography During Anesthesia for MRI in Children
Condition: Anesthesia
MeSH terms: Pulmonary Atelectasis
Study type: Observational

Summary: 
      This study investigates under controlled conditions the variation of poorly ventilated lung
      units (silent spaces) in children between 1 and 6 years of age measured by electrical
      impedance tomography during intravenous anaesthesia in a day-hospital setting and before
      discharge to help further raise safety standards in paediatric anaesthesia
    

Detailed description: 
      Eligible, children, with parental written informed consent, scheduled for a cerebral magnetic
      resonance image (MRI) will receive an intravenous anaesthesia using a Propofol infusion of 10
      mg/kg/h. At the Bern Children's Hospital all children will be premedicated with Midazolam
      rectal/oral 0.5 mg/kg or Dexmedetomidine nasal 2 mcg/kg 20 minutes before the beginning of
      the procedure Eligible children will be prepared for procedure according to the local SOPs of
      the paediatric anaesthesia departments. Mandatory monitoring will consist of: SpO2, HR, NIBP.
      An iv-line for drugs injection will be placed.

      Induction of anaesthesia: after iv-line placement a bolus of Propofol of 2 mg/kg followed by
      a continuous infusion of 10 mg/kg/h will be applied. Administration of low-flow oxygen for
      all children (0.3 l/kg/min) via Microstream® Smart CapnoLine® paediatric cannula (Philips
      Healthcare, Amsterdam, Netherlands). This cannula allows to measure the etCO2.

      In case of extremely agitated child an inhalative induction may be performed. This technique
      represent the actual standard of care and is not associated with increased risks because of
      the study.

      Before induction of the anaesthesia, before the radiological procedure when the induction is
      terminated, after the termination of the radiological procedure, before transport to the Post
      anaesthesia Care Unite (PACU), and before the discharge from the PACU after 2 hours of
      monitoring ventilation distribution changes by thoracic electrical impedance tomography are
      measured (each measurement will last 1 min).
    

Intervention name(s): electrical impedance tomography during anaesthesia
Intervention type(s): Other
Intervention description(s): Before induction of the anaesthesia, before the radiological procedure when the induction is terminated, after the termination of the radiological procedure, before transport to the Post anaesthesia Care Unite (PACU), and before the discharge from the PACU after 2 hours of monitoring ventilation distribution changes by thoracic electrical impedance tomography are measured (each measurement will last 1 min). For this, resulting potential differences are measured, and impedance distribution sampled at 30 Hz will be calculated by an automated linearized Newton-Raphson reconstruction algorithm (9). Relative change in poorly ventilated lung regions (silent spaces) and end-expiratory lung impedance (EELI) and measures of ventilation inhomogeneity such as the global inhomogeneity index will be calculated as described previously, using customised software (Matlab R2013a, The MathWorks, Nattick, Massachusetts, USA)(10-12).
Intervention MeSH terms: Anesthetics
Observational model: Other
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        We will include paediatric patients undergoing radiological procedures requiring
        intravenous anaesthesia.
      
Keywords: children; electrical impedance tomography