Premedication with midazolam in young children: a comparison of four routes of administration

BACKGROUND: We undertook a study to determine the effects of four routes of administation on the efficacy of midazolam for premedication. METHODS: In a randomized double-blind study, 119 unmedicated children, ASA I-II, aged 1.5-5 years, who were scheduled for minor elective surgery and who had been planned to received midazolam as a premedicant drug, were randomly assigned to one of four groups. Group I received intranasal midazolam 0.3 mg.kg-1; group II, oral midazolam 0.5 mg x kg(-1); group III, rectal midazolam 0.5 mg x kg(-1); and group IV, sublingual midazolam 0.3 mg x kg(-1). A blinded observer assessed the children for sedation and anxiolysis every 5 min prior to surgery. Quality of mask acceptance for induction, postanaesthesia care unit behaviour and parents' satisfaction were evaluated. Thirty patients were enrolled in each of groups I, III and IV. Twenty-nine patients were enrolled in group II. RESULTS: There were no significant differences in sedation and anxiety levels among the four groups. Average sedation and anxiolysis increased with time, achieving a maximum at 20 min in group I and at 30 min in groups II-IV. Patient mask acceptance was good for more than 75% of the children. Although the intranasal route provides a faster effect, it causes significant nasal irritation. Seventy-seven percent of the children from this group cried after drug administration. Most parents in all groups (67-73%) were satisfied with the premedication. CONCLUSIONS: Intranasal, oral, rectal and sublingual midazolam produces good levels of sedation and anxiolysis. Mask acceptance for inhalation induction was easy in the majority of children, irrespective of the route of drug administration.     

Comparison of a combination of midazolam and diazepam and midazolam alone as oral premedication on preanesthetic and emergence condition in children

BACKGROUND: Preanesthetic anxiety and emergence agitation are major challenges for anesthesiologists in pediatric anesthesia. Thus, midazolam has been used as premedication for children. However, midazolam alone is not effective for emergence agitation. The present study tested the effect of a combination of midazolam and diazepam on the preanesthetic condition and emergence behavior in children. METHODS: Forty-two children were allocated to one of three groups: the NoPre group received no premedication; the Mi group received midazolam 0.5 mg kg(-1) orally; and the Mi + Di group received midazolam 0.25 mg kg(-1) and diazepam 0.25 mg kg(-1) orally. When anesthesia was induced with 7% sevoflurane in 100% oxygen, qualities of mask induction and sedation were rated. Anesthesia was maintained with sevoflurane (3-5%) in 100% oxygen. During emergence from anesthesia, the score of the child's emergence behavior was rated. RESULTS: Children in the Mi and Mi + Di groups were more sedated than those in the NoPre group. A combination of midazolam and diazepam provided a better quality of mask induction, when compared with no premedication. Also, the children in the Mi + Di group were less agitated than those in the other groups during the emergence. CONCLUSION: Children in the Mi + Di group were significantly more sedated at induction of anesthesia and less agitated during emergence from anesthesia.     

Premedication in children: hypnosis versus midazolam

BACKGROUND: The main objectives of premedication in children are to facilitate the separation from the parents, to reduce preoperative anxiety, to smooth the induction of anesthesia and to lower the risk of postoperative behavioral disorders. The most common technique is sedative premedication with midazolam. Hypnosis enables a state of relaxation to be achieved and has never been evaluated as a premedication technique. The aim of the present study was to evaluate the efficacy of hypnosis on anxiety and perioperative behavioral disorders versus midazolam. METHODS: Fifty children from 2 to 11 years of age were randomized into two groups: group H received hypnosis as premedication; group M were given 0.5 mg x kg(-1) midazolam orally, 30 min before surgery. Preoperative anxiety was evaluated using the Modified Yale Preoperative Anxiety Scale (mYPAS) score when arriving in the department (T1), when entering the operating room (T2), and when fitting the facemask (T3). Postoperative behavioral disorders were evaluated using the Posthospitalization Behavioral Questionnaire (PHBQ) at days 1, 7 and 14. RESULTS: The two groups showed no significant difference preoperatively with the PHBQ: (M) 21 (17-25) vs (H) 20 (8-25) and mYPAS score: (M) 28 (23-75) vs (H) 23 (23-78). The number of anxious children was less during induction of anesthesia in the hypnosis group (T3: 39% vs 68%) (P < 0.05). Postoperatively, hypnosis reduced the frequency of behavior disorders approximately by half on day 1 (30% vs 62%) and day 7 (26% vs 59%). CONCLUSIONS: Hypnosis seems effective as premedication in children scheduled for surgery. It alleviates preoperative anxiety, especially during induction of anesthesia and reduces behavioral disorders during the first postoperative week.     

Effects of preanesthetic administration of midazolam, clonidine, or dexmedetomidine on postoperative pain and anxiety in children

BACKGROUND: A growing interest in the possible influences of pre- and postoperative anxiety and pain scores as outcomes of surgical treatment and benefits of anxiety or pain-reducing interventions has emerged. The aim of this study was to evaluate the influence of three different premedication regimens on postoperative pain and anxiety in children. METHODS: A prospective, randomized, open-label clinical trial enrolled 60 schoolchildren. They were randomized for premedication with oral midazolam 0.5 mgxkg(-1), oral clonidine 4 microgxkg(-1), or transmucosal dexmedetomidine (DEX) 1 mug.kg(-1), submitted to a pre- and postoperative evaluation of anxiety with the State-Trait Anxiety Inventory for Children and asked to report any pain in verbal and visual analog scales. We also evaluated secondary outcomes such as parents' anxiety, sedation, separation from parents, adverse effects and hemodynamic status. RESULTS: Dexmedetomidine and clonidine were related to lower scores of pain than midazolam. alpha(2)-agonists produced lower scores of peroperative mean arterial pressure and heart rate than midazolam. Both groups had similar levels of postoperative state-anxiety in children. There was no difference in preanesthesia levels of sedation and response to separation from parents between groups. CONCLUSIONS: These findings indicate that children receiving clonidine or DEX preoperatively have similar levels of anxiety and sedation postoperatively as those receiving midazolam. However, children given alpha(2)-agonists had less perioperative sympathetic stimulation and less postoperative pain than those given midazolam.     

Steal-induction after clonidine premedication: a comparison of the oral and nasal route

BACKGROUND: Clonidine premedication in children reliably provides preoperative sedation and anxiolysis, but onset of oral clonidine is known to be slow. Nasal clonidine has been shown to reach peak plasma levels within 10 min in rodents. The aim of the present study was to compare clinical effects and percentage of steal-induction after clonidine premedication by the oral and nasal route. METHODS: Forty children, aged 1-6 years, scheduled for minor infraumbilical surgery, were randomly assigned to receive either pure clonidine 4 microgxkg(-1) intranasally (group CN, n = 20) or clonidine 4 microgxkg(-1) orally in syrup (group CO, n = 20) prior to mask induction. Drug acceptance, preoperative sedation and anxiolysis, quality of mask acceptance, recovery profile and parents' satisfaction were evaluated. RESULTS: Drug acceptance was similar between groups, but quality of taste was significantly better in the oral group. There was no significant difference of preoperative anxiolysis and sedation. The onset of sedative effect was after 38.3 min for oral clonidine and 47.5 min for nasal clonidine. A steal-induction could be performed in 60% of children in each group. Emergence from anesthesia and parents' satisfaction were comparable. CONCLUSIONS: Intranasal clonidine administration has no advantage over the oral route. Clinical effects were similar with both routes; there was a trend towards a faster onset of sedation with oral clonidine. Clonidine premedication causes light sleep, which allows a steal-induction in 60% of patients.     

Postoperative recovery in preschool-aged children: A secondary analysis of a randomized controlled trial comparing premedication with midazolam,clonidine, and dexmedetomidine

Background

Preoperative anxiety in pediatric patients can worsen postoperative outcomes and delay discharge. Drugs aimed at reducing preoperative anxiety and facilitating postoperative recovery are available; however, their effects on postoperative recovery from propofol-remifentanil anesthesia have not been studied in preschool-aged children. Thus, we aimed to investigate the effects of three sedative premedications on postoperative recovery from total intravenous anesthesia in children aged 2–6 years.

Methods

In this prespecified secondary analysis of a double-blinded randomized trial, 90 children scheduled for ear, nose, and throat surgery were randomized (1:1:1) to receive sedative premedication: oral midazolam 0.5 mg/kg, oral clonidine 4 μg/kg, or intranasal dexmedetomidine 2 μg/kg. Using validated instruments, outcome measures including time for readiness to discharge from the postoperative care unit, postoperative sedation, emergence delirium, anxiety, pain, and nausea/vomiting were measured.

Results

After excluding eight children due to drug refusal or deviation from the protocol, 82 children were included in this study. No differences were found between the groups in terms of median time [interquartile range] to readiness for discharge (midazolam, 90 min [48]; clonidine, 80 min [46]; dexmedetomidine 100.5 min [42]). Compared to the midazolam group, logistic regression with a mixed model and repeated measures approach found no differences in sedation, less emergence delirium, and less pain in the dexmedetomidine group, and less anxiety in both clonidine and dexmedetomidine groups.

Conclusions

No statistical difference was observed in the postoperative recovery times between the premedication regimens. Compared with midazolam, dexmedetomidine was favorable in reducing both emergence delirium and pain in the postoperative care unit, and both clonidine and dexmedetomidine reduced anxiety in the postoperative care unit. Our results indicated that premedication with α₂-agonists had a better recovery profile than short-acting benzodiazepines; although the overall recovery time in the postoperative care unit was not affected.     

Premedication for outpatient cataract surgery: a comparative study of intramuscular alfentanil, midazolam and placebo

The effects of i.m. alfentanil and midazolam on anxiety, sedation, hemodynamics, oxygen saturation and intraocular pressure were studied in 90 patients scheduled for outpatient cataract surgery with regional anesthesia. The study was randomized, double-blind, placebo-controlled, and performed on outpatients with ASA physical status I-III and mean age 67.7 +/- 11.7 years. Alfentanil (12.5 micrograms/kg) administered into the deltoid muscle had a marked anxiolytic and short sedative effect, and was associated with stable hemodynamics. Midazolam (20 micrograms/kg) administered similarly had a more prolonged anxiolytic and sedative effect, which impaired co-operation in some patients during surgery. The regional blockade was associated with a significant reduction of oxygen saturation (SpO2), regardless of the premedication used (P less than 0.05). A slight reduction of intraocular pressure (IOP) was found after premedication, but the change was not statistically significant. We conclude that i.m. alfentanil is well tolerated, and its anxiolytic and short sedative effects make it especially suitable as premedication for day-case cataract surgery.     

Evaluation of relatively low dose of oral transmucosal ketamine premedication in children: a comparison with oral midazolam

BACKGROUND: Oral Transmucosal ketamine (lollipop) has been shown to be an effective, harmless preoperative medication for children. However, its efficacy was not compared with commonly used premedication drugs. We, therefore, compared the efficacy of oral transmucosal ketamine with oral midazolam for premedication in children. METHODS: Fifty-five children (2-6 years of age) were randomized to receive orally either a lollipop containing 50 mg of ketamine (the group K; n = 27) or syrup containing 0.5 mg.kg(-1) of midazolam (the group M; n = 28) before minor surgery. A five points-sedation score (1 = asleep to 5 = agitated; scores 2 and 3 were defined as 'effective') on arrival in the operating room and a three points-acceptance score of separation from the parents and a three points-mask cooperation score at induction of anesthesia (1 = easy to 3 = markedly resistant; score 3 was defined as 'poor') were used. RESULTS: Sedation scores in group K were significantly higher than those in group M (P = 0.012), and the incidence of 'effective' in sedation was significantly lower in group K than in group M (P = 0.036). The incidence of 'poor' at separation from the parents and for mask cooperation was significantly higher in group K than in group M (P = 0.017, P = 0.019, respectively). CONCLUSION: These results indicate that a relatively low dose of oral transmucosal ketamine premedication provides no benefits over oral midazolam in children.     

Dexmedetomidine vs midazolam for premedication of pediatric patients undergoing anesthesia

Background: Dexmedetomidine, an α₂‐receptor agonist, provides sedation, analgesia, and anxiolytic effects, and these properties make it a potentially useful anesthetic premedication. In this study, we compared the effects of intranasal dexmedetomidine and midazolam on mask induction and preoperative sedation in pediatric patients. Methods: Ninety children classified as ASA physical status I, aged between 2 and 9, who were scheduled to undergo an elective adenotonsillectomy, were enrolled for a prospective, randomized, and double‐blind controlled trial. All of the children received intranasal medication approximately 45–60 min before the induction of anesthesia. Group M (n = 45) received 0.2 mg·kg^?1 of intranasal midazolam, and Group D (n = 45) received 1 μg·kg^?1 of intranasal dexmedetomidine. All of the patients were anesthetized with nitrous oxide, oxygen, and sevoflurane, administered via a face mask. The primary end point was satisfactory mask induction, and the secondary end points included satisfactory sedation upon separation from parents, hemodynamic change, postoperative analgesia, and agitation score at emergence. Results: Satisfactory mask induction was achieved by 82.2% of Group M and 60% of Group D (P = 0.01). There was no evidence of a difference between the groups in either sedation score (P = 0.36) or anxiety score (P = 0.56) upon separation from parents. The number of patients who required postoperative analgesia was higher in the midazolam group (P = 0.045). Conclusion: Intranasal dexmedetomidine and midazolam are equally effective in decreasing anxiety upon separation from parents; however, midazolam is superior in providing satisfactory conditions during mask induction.     

Premedication with midazolam in out-patient general anaesthesia. A comparison with morphine-scopolamine and placebo

Strong premedication may prolong recovery and cause side-effects after short surgical procedures in general anaesthesia. To be operated without premedication may be unpleasant for the patient. Midazolam is a water-soluble benzodiazepine with rapid onset and short half-life. In a randomized study with 193 female patients, we compared the effects and side-effects of three different premedicants i.m.: midazolam, morphine-scopolamine (Mo-Scop) and placebo. Midazolam and Mo-Scop had an equal and significantly better effect than placebo on preoperative anxiety and alertness. Side-effects like nausea, dry mouth and prolonged recovery occurred significantly more often in the Mo-Scop than the midazolam or placebo groups. The midazolam-premedicated patients had significantly more amnesia compared with the other two groups. Only 3% of the patients would prefer no medication before anaesthesia, whereas 80% would prefer a combination of an anxiolytic and hypnotic premedication. Sixty-three percent of the patients would prefer a premedicant administered by injection. The results indicate that midazolam i.m. is an effective premedicant, with few side-effects, for short procedures in general anaesthesia.     

Rectal midazolam as premedicant in children: a dose response study

Rectally administered midazolam has proved to be a reliable and acceptable way of premedicating children. In order to determine the optimal dose 80 children were randomized in a double-blind manner to receive one of four different dosages of midazolam (0.2–0.3–0.4–0.5 mg·kg⁻¹) in combination with atropine 0.02 mg·kg⁻¹ rectally. Observations before and after premedication showed no clinically relevant differences in ventilatory and cardiovascular parameters. Neither did the groups differ as regards acceptance of the mask or awakening from anaesthesia. Regardless of group the level of sedation was increased, but only children receiving 0.4 or 0.5 mg·kg⁻¹ of midazolam showed an increase in the level of anxiolysis. For this reason a low dose of midazolam (0.2 mg·kg⁻¹) can be used, except in cases where pronounced anxiolysis is required.     

Emergence agitation after cataract surgery in children: a comparison of midazolam,propofol and ketamine

Objectives: The aim of this study was to determine whether the concurrent use of either of a subhypnotic dose of midazolam, propofol or ketamine with fentanyl just before discontinuing the sevoflurane anesthesia would effectively sedate the children as they recovered and significantly decrease the incidence and severity of emergence agitation and would not delay patient awakening and discharge. Background: Postoperative emergence agitation may occur in children after general anesthesia with volatile anesthetics. Children who undergo cataract surgery after sevoflurane induction and sevoflurane–remifentanil maintenance may experience this type of agitation. Methods/Materials: In 120 un‐premedicated children aged 1–7 years, mask induction with sevoflurane was performed and they were then randomly assigned to one of the three antiagitation postoperative groups (n = 40). We studied the postoperative antiagitation effects of subhypnotic doses of midazolam combined with fentanyl, propofol with fentanyl or ketamine with fentanyl administered just before discontinuing the sevoflurane anesthesia. A score for the level of agitation can be assigned based on the recovery mental state (RMS) scale and the recently published pediatric anesthesia emergence delirium scale (PAED). Postoperative factors assessed included emergence behaviors, the time to eye opening, the time to discharge from the postanesthesia care unit (PACU) to the ward. Results: There were significantly more agitated children in the ketamine‐group when compared to the midazolam‐group or to the propofol‐group at all time P < 0.05), especially at 10 and 15 min. The PAED scale showed a significant advantage for midazolam–fentanyl [5 (2–15)] and propofol–fentanyl [6 (3–15)] versus ketamine–fentanyl [10 (3–20)] (P < 0.05). The time to discharge from the PACU to the ward was not significantly different among the groups. Conclusions: Intravenous administration of a subhypnotic dose of midazolam or propofol in addition to a low dose of fentanyl just before discontinuing the sevoflurane anesthesia was both effective on decreasing the incidence and severity of emergence agitation in children undergoing cataract extraction without significant delaying recovery time and discharge. The effect of midazolam was clearer than that seen with propofol.     

A comparison of two different doses of ketamine with midazolam and midazolam alone as oral preanaesthetic medication on recovery after sevoflurane anaesthesia in children

BACKGROUND: This investigation prospectively evaluated the effect of oral premedication of two different doses of ketamine with midazolam and midazolam alone on the recovery of children after sevoflurane anaesthesia. METHODS: In a randomized, double-blind study, 79 children (aged 1-8 years, ASA physical status I or II) were assigned to receive one of three premedications in a volume of 0.5 ml x kg(-1): group 1 received midazolam 0.5 mg x kg(-1) (MD); group 2 received midazolam 0.5 mg x kg(-1) with ketamine 1.8 mg x kg(-1) (MK-1); and group 3 received midazolam 0.5 mg x kg(-1) with ketamine 3 mg x kg(-1) (MK-2). The reactions of the children during administration were noted. Anaesthesia was induced by facemask with incremental sevoflurane administration. All children received alfentanil (15 micro g x kg(-1)). Tracheal intubation was facilitated by mivacurium (0.2 mg x kg(-1)). Anaesthesia was maintained with sevoflurane and an additional dose of alfentanil, if necessary. During recovery, the time interval between discontinuation of anaesthesia and arousal (spontaneous ventilation, extubation) were recorded. RESULTS: Emergence (spontaneous ventilation, extubation) and recovery times (discharge, Aldrete score=9) did not differ significantly between groups (P=0.24, P=0.59 and P=0.145, respectively). CONCLUSIONS: The combination of midazolam and ketamine as oral preanaesthetic medication did not significantly affect the recovery time of children after sevoflurane anaesthesia.     

Comparison of rectal to intramuscular administration of midazolam and atropine for premedication of children

The effectiveness of midazolam and atropine as anaesthetic premedication was investigated, comparing rectal to intramuscular administration. A total of 202 children varying in age from 10 months to 9 years, who had been admitted to the Day Surgery Department for short ENT procedures, were assigned to one of two groups on a random basis. The first group (n = 102) was given 0.5 mg/kg midazolam and 0.05 mg/kg atropine as a rectal solution 30 to 75 min prior to induction, while the second group (n = 100) was given 0.15 mg/kg midazolam and 0.02 mg/kg atropine as an intramuscular injection 20 to 60 min prior to induction. The levels of sedation and salivation were compared, as was the degree of tolerance to intravenous induction. The parents of children older than 3 years of age were given a questionnaire designed to determine the degree of amnesia. We found this combination of drugs to be effective in the relief of anxiety, the inhibition of salivary secretion and the promotion of memory loss, regardless of the route of administration. We feel that rectal administration is preferable because it is not associated with pain or anxiety.     

Premedication of children with oral midazolam

In a randomized, double-blind, placebo-controlled study, the safety, efficacy and feasibility of oral midazolam premedication in children were evaluated in an ambulatory surgery unit. Eighty unmedicated children (ASA PS I or II, ages 1-6 yr) were randomly assigned to one of four groups receiving midazolam 0.5, 0.75, or 1.0 mg.kg-1 or a placebo 30 min before separation from parents. Heart rate, systolic blood pressure, arterial oxygen saturation, respiratory rate, sedation and anxiolysis scores were recorded before premedication, every five minutes for 30 min and then during induction of anaesthesia and recovery. We found that heart rate, systolic blood pressure, arterial oxygen saturation and respiratory rate were unchanged during the study. Sedation and anxiolysis scores in the midazolam-treated groups were greater than those in the placebo group and that anxiolysis at the time of separation from the parents was judged excellent in 80-90% of the children who received midazolam. However, sedation and anxiolysis did not differ among the three midazolam groups. Mean times to discharge from hospital were similar for all four groups. The side effects, loss of balance and head control, blurred vision and dysphoric reactions were observed only in the 0.75 and 1.0 mg.kg-1 midazolam groups. We conclude that oral midazolam 0.5 mg.kg-1 is a safe and effective premedication and that 0.75 and 1 mg.kg-1 while offering no additional benefit, may cause more side effects.     

Sublingual midazolam premedication in children: a dose response study

The purpose of this study was to evaluate various doses of sublingual midazolam premedication in children. In our prospective, double-blind, placebo-controlled trial, children (n=102, age range 12 to 129 months) scheduled for day surgery were randomized to receive either midazolam in one of three doses (0.25, 0.5, or 0.75 mg·kg^?1) or placebo. Injectable midazolam was mixed with a thick grape syrup and placed under the tongue; the patient was asked to hold it as long as possible before swallowing. Children readily accepted the mixture. Analysing all patients randomized, none of the children receiving placebo vs 28% receiving 0.25 mg·kg^?1 (P=0.02), 52% receiving 0.5 mg·kg^?1 (P<0.001), and 64% receiving 0.75 mg·kg^?1 (P<0.001) of midazolam showed satisfactory sedation (drowsy) at 15 min after administration. Children receiving the two higher doses of midazolam (0.5 and 0.75 mg·kg^?1) accepted mask induction willingly, while the group receiving 0.25 mg·kg^?1 resembled the placebo group (P<0.05).     

Efficacy of two oral premedicants: midazolam or a low‐dose combination of midazolam–ketamine for reducing stress during intravenous cannulation in children undergoing CT imaging

Background: Pain, anxiety and fear of needles make intravenous cannulation extremely difficult in children. We assessed the efficacy and safety of oral midazolam and a low‐dose combination of midazolam and ketamine to reduce the stress and anxiety during intravenous cannulation in children undergoing computed tomography (CT) imaging when compared to placebo. Methods: Ninety‐two ASA I or II children (1–5 years) scheduled for CT imaging under sedation were studied. Children were randomized to one of the three groups. Group M received 0.5 mg·kg^?1 midazolam in 5 ml of honey, group MK received 0.25 mg·kg^?1 midazolam mixed with 1 mg·kg^?1 ketamine in 5‐ml honey and group P received 5‐ml honey alone, orally. In 20–30 min after premedication, venipuncture was attempted at the site of eutectic mixture of local anesthetics cream. Sedation scores and venipuncture scores were recorded. Primary outcome of the study was incidence of children crying at venipuncture (venipuncture score of 4). Results: Significantly more children cried during venipuncture in placebo group compared to the other two groups (19/32 (59%) in group P vs 1 each in groups M and MK, (P < 0.001) (RR 2.37, 95% CI 1.55‐3.63). In 20–30 min after premedication, group P had more children in sedation score 1 or 2 (crying or anxious) compared to the other two groups (P < 0.05). At this time, group MK showed more children in calm and awake compared to group M (P = 0.02). At venipuncture, group P had more children in venipuncture score 3 or 4 (crying or withdrawing) compared to group M or MK (P < 0.05), while groups M and MK were comparable. Conclusion: A low‐dose combination of oral midazolam and ketamine or oral midazolam alone effectively reduces the stress during intravenous cannulation in children undergoing CT imaging without any adverse effects. However, the combination provides more children in calm and quiet state when compared to midazolam alone at venipuncture.     

Oral midazolam premedication and postoperative behaviour in children

We examined the effect of oral midazolam premedication on postoperative behaviour. Seventy children (ASA Physical Status 1 and 2; aged 1–10 yrs) were assigned randomly in a prospective, blinded fashion to receive either midazolam 0.5 mg·kg⁻¹ (maximum 10 mg) or placebo. Behaviour assessments were made prior to medication, during induction of anaesthesia and 15 min following arrival to recovery room. The baseline behavioural evaluation scores were not significantly different. The children receiving midazolam cried significantly less during induction (P≤0.02). At one week follow-up, eight of 35 subjects receiving placebo had experienced adverse behaviour changes (nightmares, night terrors, food rejection, anxiety, negativism); 19 of 35 of the midazolam group experienced these changes (P≤0.02). At four week follow-up, most behaviour changes had resolved. Children given preoperative oral midazolam were less likely to cry and fight while being anaesthetized, and preoperative sedation was associated with increased incidence of adverse postoperative behaviour changes.