changes in circadian rhythm after anaesthesia in children

Conditions: Circadian Rhythm Sleep Disorder; Circadian Rhythm Disorder Caused by Drug; Circadian Rhythm Sleep Disorder, Jet Lag Type; Jet Lag; Anesthesia; Sleep; Sleep Disorders, Circadian Rhythm; Sleep Disturbance

Summary: in this study the investigators will examine the effect of general anesthesia and surgery on sleep duration and sleep quality in children, using questionnaires and a sleep diary.

objective: the primary objective is to assess the effect of general anaesthesia and surgery on sleep duration (chronotype) and sleep quality in children aged 1-11 years in the first week after surgery. secondary objectives are to determine the duration of the effect of general anaesthesia on chronotype and sleep quality. furthermore, the investigators will examine factors which may be of influence on the quality and duration of sleep, like postoperative emergence delirium, admission to the hospital, face, legs, activity, cry, consolability scale (flacc) / numeric rating scale (nrs) scores, preoperative sedative medication and postoperative sedative medication. study procedures: possible participants will be identified on the anaesthetic pre-operative assessment clinic and asked if they object to a phone call with information about research. if not, a researcher will contact the parents by telephone to inform them about the study. after oral consent by both parents, an invitation to fill in the questionnaires will be sent to the parents together with a consent form. informed consent by both parents will be obtained. questionnaires can be completed online or on paper, depending on the parents' preference. questionnaires: * sleep quality: child's sleep habits questionnaire (cshq) on day 3 preoperative and on day 7 postoperative. * chronotype: children's chronotype questionnaire on day 3 preoperative * daily sleep diary starting from 3 days preoperative until 7 days postoperative the following items will be extracted from the electronic health record: * demographic criteria: age, gender, type of procedure * admission dates * preoperative sedative medication * postoperative sedative medication * nrs/flacc scores during hospital stay all items will be entered in an electronic database (castor) primary endpoint the diurnal phase shift the night after surgery, measured by comparing the midpoint of sleep three nights before surgery (as measured by the sleeping log) with midpoint of sleep the night after surgery. secondary endpoints * change in sleep quality as measured with the cshq questionnaire * incidence of postoperative sleep problems as measured with the cshq questionnaire * difference in sleep problems, sleep duration and sleep quality between children who had anaesthesia for magnetic resonance imaging and children who had anaesthesia and surgery * influence of pain and sedative medication on sleep duration and quality

Eligibility criteria:
inclusion criteria: * general anaesthesia for surgery or magnetic resonance imaging (mri) with a minimal duration of 30 minutes * age 1-11 years * informed consent of both parents exclusion criteria: * parents are not fluent in dutch * known severe sleep disturbances * postoperative admission to paediatric intensive care unit * moderate to severe developmental disorder (iq\<85) * american society of anesthesiologists (asa) classification \> 3