'The frequency of behaviour disturbances after different concentration of anaesthetic gases (Sevoflurane) for anaesthesia during M.R.I. examination in children.

Rationale:

‘Emergence delirium’ (ED) is described as a mental disorder during recovery from general anaesthesia. After the introduction of new inhalation anaesthetics such as Sevoflurane, this phenomenon again gained prominence. The specific cause is unknown. Anaesthesia, surgery and patient related factors are part of the possible explanations.



Objective of the research:

The primary research inquiry being raised concerns anaesthesia related causes:
Is it possible that adapting an amount of Sevoflurane, from 1 MAC (minimum alveolar concentration) (2,5 vol%) to ½ MAC (1,25 vol%) in an MRI scan can reduce the frequency and gravity of ‘emergence delirium’?

The secondary research inquiry being raised concerns patient related causes:
Are parents’ and children’s anxiety at induction, as well as their behaviour, a predictive value for the appearance of ‘ED’?



Study design:

Randomised double-blinded research on 2 groups of children ranging from 1.5 to 5 years old.
Study population: 110 children who have to undergo an MRI scan for diagnostic reasons. Intervention: during the diagnostic research 1 MAC (2,5 vol%) or ½ MAC (1,25 vol%) Sevoflurane is administered.



Main study parameters/endpoints:

The primary endpoints are the maximum scores on the ‘Pediatric Anesthesia Emergence Delirium Scale’ (PAED) until 1 hour after having stopped the administration of the anaesthetic. We consider a score of >12 on the PAED scale as cut-off for the presence or absence of ED. The secondary endpoints are the time between terminating the administration and the removal of the laryngeal mask airway and the time of reaction (‘responsiveness’) to light or gentle tactile stimulation.



Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

This research does not lead to an increased risk. The risk is similar to the one for general anaesthesia. The accompanying parent will be presented with two short questionnaires (duration maximum 15 min.). A subpopulation of young preschool children seems to be most vulnerable to ‘emergence delirium’. With this research our anaesthesia policy is thus adapted to prevent ‘ED’. Even though there is no standard technique for the admission of anaesthesia during a MRI scan, the administering of a Sevoflurane concentration around 1 MAC is considered most common. A deviation from this common rule, the administering of a lower concentration of Sevoflurane to avoid ED, is therefore a therapeutic intervention.

1. The primary research inquiry being raised concerns anaesthesia related causes:
Is it possible that adapting an amount of Sevoflurane, from 1 MAC (minimum alveolar concentration) (2,5 vol%) to ½ MAC (1,25 vol%) in an MRI scan can reduce the frequency and gravity of emergence delirium?

2. The secondary research inquiry being raised concerns patient related causes:

Are parents and childrens anxiety at induction, as well as their behaviour, a predictive value for the appearance of ED?

During the first hour after the awakening constant observation is done and the behaviour of the child is assessed in the recovery room by using the Pediatric Anesthesia Emergence Delirium (PAED) scale. A total sum of > 12 on the scale creates is chosen as distinction between presence or absence of clinical relevant agitation.

The anxiety level and the need for information of the accompanying parent is measured by using the Amsterdam Preoperative Anxiety and Information Scale (APAIS).

The behavior of the child is measured by using the CBLC/11/2-5, Child Behavior Checklist for Ages 11/2-5).

At admission in the day case hospital the anxiety level is measured for a first time by using the modified Yale Preoperative Anxiety Scale (m-YPAS) and a second time at induction.

We use the University of Michigan Sedation Scale (UMSS scale) to determine when we apply the first measurement of the Pediatric Anesthesia Emergence Delerium (PAED) scale and chose a score of 3 as a point of reference.

during the diagnostic research 1 MAC (2,5 vol%) or ½ MAC (1,25 vol%) Sevoflurane is administered.