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.     

Usefulness of oral hypnotic premedication for volatile induction of anesthesia in adults

Purpose. We investigated the effects of oral hypnotic premedication for smooth anesthetic induction and for the patient's comfort under anesthesia, using sevoflurane without nitrous oxide. Methods. Adult patients were divided into four groups: control (n= 12), triazolam (0.25 mg; n= 12), zopiclone (7.5 mg; n= 12), and clonidine (0.15 mg; n= 12) groups. Each premedication was given to each patient 1 h before the anesthesia. The patients breathed out to residual volume and then the anesthetic mask was fitted. The repeated vital capacity breathing technique was used, with 5% sevoflurane in 10 l·min⁻¹ oxygen. Induction time, specific induction side effects, and acceptability of this technique by the patients were recorded by an independent observer. Results. Induction time in the premedicated groups ranged from 66 ± 12 s (mean ± SD) to 76 ± 14 s, and these values were significantly shorter than that in the control group (92 ± 16 s). The number of patients in whom adverse effects occurred during anesthetic induction was significantly greater in the control group (4 patients; 33%) than in the premedicated groups (1 patient each; 8%). Acceptability of the smell of sevoflurane was significantly higher in the premedicated groups (8–10 patients; 67%–83%) than in the control group (5 patients; 42%). Conclusion. Oral hypnotic premedications with either triazolam (0.25 mg), zopiclone (7.5 mg), or clonidine (0.15 mg) are recommended for smoother volatile anesthetic induction and for the patient's comfort in adults. Received: January 28, 2002 / Accepted: April 26, 2002     

Midazolam (Dormicum) as oral premedication for local anesthesia

Good physician-patient rapport and an anxiolytic, sedative, and amnesic premedication are necessary for comfortable, stress-free surgery under local anesthesia. Sufficient experience exists with the intramuscular and intravenous administration of the new benzodiazepine midazolam (Dormicum), while knowledge relating to its oral administration is still scant. Therefore, in a randomized double-blind study midazolam was investigated for oral premedication prior to local anesthesia: two dosages of midazolam were studied and compared with diazepam and placebo. One hour prior to ophthalmic surgery under local anesthesia, four randomized groups of 30 patients each, received a tablet of 7.5 or 15 mg midazolam, 10 mg diazepam, or a placebo. Following this medication, the anxiolytic, sedative, amnesic, and side-effects were determined at defined points of time during the day of surgery and the 1st postoperative day. Anxiolysis was determined using the "state-trait anxiety inventory (STAI)" of Spielberger et al.; sedation was assessed according to Pandit et al.; amnesia was determined by recall of picture cards which had been presented to the patients 50 min after premedication; and patients were asked about 13 side-effects typical of benzodiazepines in a standardized way. Anxiety increased little following the placebo; it decreased significantly following 10 mg diazepam and more markedly following 7.5 and 15 mg midazolam. Sedation increased little following the placebo; it increased more and similarly 50 min after the benzodiazepines; after 90 min the sedative effect was most marked for 15 mg midazolam. However, sedation was of shorter duration after midazolam than after diazepam.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oral transmucosal midazolam premedication for preschool children

PURPOSE: To evaluate the acceptance and effectiveness of 0.2 mg x kg(-1) of oral transmucosal midazolam as a premedicant in infants and preschool children. METHOD: In a randomized, prospective double-blind placebo controlled study, 44 healthy children, between the ages of eight months to six years, presenting for elective surgery were divided in two groups. The medicated group received 0.2 mg x kg(-1) of injectable midazolam mixed with an equal volume of strawberry syrup and the placebo group received plain syrup 0.08 ml x kg(-1). Medications were placed on the anterosuperior aspect of the child's tongue in 3-5 aliquots of 0.2-0.4 ml. A blinded observer assessed the acceptance of the medication by willingness to open the mouth for the next aliquot and the efficacy of the medication was assessed by ease of separation from the parent. RESULTS: Ninety-six percent of the children in the placebo group and 95% in the midazolam group willingly accepted the medication. Separation of children from parents was successful in 95% of the medicated children compared with 59% in the placebo group (P = 0.006). CONCLUSION: Oral midazolam in thick strawberry syrup, administered in small aliquots via the oral transmucosal route was well accepted and proved to be an effective premedicant in infants and preschool children.     

Oral midazolam in paediatric premedication

In a premedication study involving 135 children, aged 1-10 years, four regimens were investigated: (i) no premedication; (ii) oral trimeprazine tartrate 2 mg/kg, methadone 0.1 mg/kg, droperidol 0.15 mg/kg (TMD); (iii) intramuscular midazolam (Dormicum; Roche) 0.15 mg/kg; and (iv) oral midazolam 0.45 mg/kg. All premedications were given 60 minutes before a standard halothane anaesthetic. No impairment of cardiovascular stability occurred but after premedication the mean oxygen saturation decreased by 1.6% and 1.1%, respectively, in the intramuscular midazolam and TMD groups. Overall, children under 5 years of age behaved less satisfactorily in the holding room and at induction, than those over 5 years (P less than 0.01). Midazolam, intramuscularly and orally, produced more satisfactory behaviour than the other two regimens (P less than 0.05) and, combined with a 70% more rapid recovery than the TMD regimen (P less than 0.05), suggests that oral midazolam is a more effective paediatric premedication agent than placebo or TMD.     

Patient-controlled premedication by iv midazolam for ambulatory surgery

Applying the principle and equipment of patient-controlled analgesia, this double-blind randomised study was designed to determine the premedication dose of midazolam and to provide information about the need for preoperative anxiety control. The effects of patient-controlled premedication by iv midazolam were compared to those of a 1-hour iv infusion of a fixed dose of 4 mg. Two groups of 25 patients were studied prior to ambulatory surgery. Using a visual analogue scale graded from 0 (no anxiety) to 100, anxiety and short-term memory as well as vital signs, vigilance, cognition and orientation were assessed before premedication and then every 20 min until admission to the operating room. In both groups, 40% of the patients were free of anxiety before prernedication. Sixty-four percent of patients in the self-premedicated group never used the pump. The dose of midazolam was only 0.7 0.2 mg (mean SD) in this group taken as a whole, 0.7 1.1 mg (mean SD) in the 8 patients who had an anxiety score at least equal to 50 before premedication, and 1.7 0.3 mg (mean SD) in the 9 patients who chose to push the button of the patient-controlled device. Anxiety and short-term memory scores decreased significantly and similarly in the self-prernedicated group and in the fixed-dose group. For similar intraoperative anaesthetic requirements, time from the end of anaesthesia for determining whether a patient was ready for admission to the postrecovery lounge was shorter in the self-premedicated group (26±8 min vs 32±8 min; mean±SD. Reduced doses of midazolam self-administered via a patient-controlled device can result in a relaxed preoperative period and amnesia in ambulatory surgery patients. However, the level of anxiety before prernedication was low, which calls into question the legitimacy of the patient-controlled premedication in this kind of population. The expense of the pump was not justified by the small number of patients using it, probably because they were worried by the technical nature and the invasiveness of this technique.     

Oral midazolam premedication for paediatric day case patients

Forty-nine children having day-stay surgical procedures were randomly assigned to receive oral midazolam 0.75 mg·kg^?1 or placebo in a double blind fashion. The child's level of anxiety was assessed before premedication using parental, child and observer scales. The child and observer anxiety scores were repeated in the anaesthetic room. Most children presented for anaesthesia in a calm state, irrespective of whether they had received midazolam. Parents tended to overestimate their child's level of anxiety. Observer anxiety scores reliably predicted behaviour during induction of anaesthesia in the absence of a sedative. Observer scores decreased in the midazolam group (P<0.02), but not in the placebo group, children below six years having the greatest decrease with midazolam. The median time to discharge from hospital was delayed by 30 min in the midazolam group (P<0.01). Children do not require routine sedative premedication for day case procedures, but oral midazolam is useful in producing calm behaviour in those children with high observer anxiety scores.     

The use of midazolam in premedication

Socio-psychological factors, such as increased anxiety in developed societies and cultures, and separation anxiety, particularly in children, justify the use of premedicants. In addition, the link between a central nervous "anxiety centre" and biochemical stress responses is blocked by an efficient anxiolytic. The elimination half-life of midazolam is longer in the elderly than in the young and in the obese than in the thin, which demands longer intervals between repeated doses in old and fat patients. The hypoxic ventilatory response is depressed in most patients and the ventilatory CO₂ response in patients with chronic pulmonary disorders, which justifies increased monitoring of O₂ saturations. It is important for the choice of dose and for estimating the duration of recovery time to know that midazolam is at least four times as potent as diazepam.     

咪达唑仑术前用药预防短小手术患儿七氟醚麻醉恢复期躁动的效果

目的 评价眯达唑仑术前用药预防短小手术患儿七氟醚麻醉恢复期躁动(EA)的效果.方法 择期扁桃体联合腺样体切除术患儿120例,性别不限,年龄3～9岁,体重15～35 kg,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将其分为4组(n=30),麻醉前30 min,对照组(C组)口服10％葡萄糖10 ml,不同剂量咪达唑仑组(M1-3组)分别口服0.25、0.50和0.75 mg/kg咪达唑仑与10％葡萄糖混合液10 ml.吸入七氟醚麻醉诱导,静脉输注瑞芬太尼和吸入七氟醚维持麻醉.采用患儿麻醉恢复期躁动量化评分表(PAED)评价患儿EA的发生情况.结果 与C组比较,M2组和M3组PAED评分及EA发生率降低(P＜0.05),M1组差异无统计学意义(P＞0.05);与M1组比较,M2组和M3组PAED评分及EA发生率降低(P＜0.05);与M2组比较,M3组PAED评分及EA发生率差异无统计学意义(P＞0.05).结论 口服咪达唑仑术前用药可预防患儿短小手术七氟醚麻醉恢复期躁动,其适宜剂量为0.50 mg/kg.     

Serum potassium after enflurane-succinylcholine induction of anesthesia in children receiving rectal midazolam as premedication.

The administration of succinylcholine causes an increase in serum potassium (K+) concentrations in healthy patients. The purpose of this study was to investigate serum K+ changes following intravenous succinylcholine in children and to evaluate the effect of rectal midazolam pretreatment on these changes. Forty healthy children between the ages of 2 and 7 yr, and who were to undergo oral surgical procedures under general anesthesia were randomly assigned to receive either placebo (saline) or 0.25, 0.35, or 0.45 mg/kg midazolam administered rectally as premedication 30 min before induction of inhalational anesthesia. Blood was drawn after induction with enflurane and at 1, 2, 3, 4, and 5 min after administration of 1 mg/kg succinylcholine to determine changes in serum K+. Although the results indicate a significant increase in serum K+ after succinylcholine in all groups, midazolam pretreatment failed to cause any observable attenuation in the hyperkalemic response.     

Comparison of zopiclone and midazolam premedication for preoperative anxiolysis

To compare the anxiolysis property of zopiclone (ZPC) and midazolam (MDZ), 117 patients were given zopiclone 7.5 mg p.o. or midazolam 0.05 mg.kg-1 i.m. as premedication. In the study 1, patients were randomly allocated to 4 groups: ZZ group (n = 16) received ZPC in the night before operation and 2 h before operation, ZM group (n = 18) received ZPC in the night before operation and MDZ 1 h before operation, Z group (n = 18) received ZPC 2 h before operation, and M group (n = 24) received MDZ 1 h before operation. The degree of anxiety was evaluated using the state-trait anxiety inventory (STAI) on the day before operation and after receiving premedication. ZPC showed a significant reduction in the STAI score in the ZZ and Z group, but premedication with MDZ showed no changes in the STAI score. In the study 2, patients were randomly allocated to 2 groups: ZPC group (n = 22) received ZPC 2 h before operation, and M group (n = 19) received MDZ 1 h before operation. The degree of anxiety was evaluated using the visual analog scale (VAS) on the day before operation and after receiving premedication. ZPC showed a significant reduction in the VAS score, but MDZ showed no changes in the VAS. It is concluded that ZPC (7.5 mg p.o.) is suitable to reduce the preoperative anxiety in patients who are to undergo surgery as compared to MDZ (0.05 mg.kg-1 i.m.).     

Intramuscular midazolam premedication in small children

Midazolam 0.2 mg/kg was compared as an intramuscular premedication in small children with papaveretum and hyoscine 0.4 and 0.008 mg/kg. Midazolam produced satisfactory sedation and anxiolysis and in the early postoperative period patients were significantly more awake (p less than 0.05).     

Accidental overdose of midazolam as intramuscular premedication

We report two cases of overdoses of intramuscular midazolam used as a premedication. Both cases had no resedation or complications, but the accidents happened as a result of a resident and nurse's lack of experience with midazolam. The intramuscular doses, given at four times the normal quantity, fortunately caused no harm in our cases. However, the situations suggest that we should carefully check the dosage and review the correct procedures, even when using a drug that is considered to be familiar with most practitioners.