Premedication in children: a comparison of oral midazolam and oral clonidine

BACKGROUND: Oral premedication is widely used in pediatric anesthesia to reduce preoperative anxiety and ensure smooth induction. Midazolam is currently the most commonly used premedicant, but good results have also been reported with clonidine. The aim of the present study was to compare clinical effects of oral midazolam and oral clonidine. METHODS: We performed a prospective open study in 64 children who were randomly assigned to receive either oral midazolam 0.5 mg.kg (-1) (group M) or oral clonidine 4 microg.kg (-1) (group C) prior to mask induction. Drug acceptance, preoperative sedation and anxiolysis, quality of mask acceptance, recovery profile and parental satisfaction were evaluated. RESULTS: The taste of oral clonidine was judged as significantly better; 14% of children rejected oral midazolam. Onset of sedation was significantly faster after premedication with midazolam (30+/-13.1 min) than with clonidine (38.5+/-14.6 min), but level of sedation was significantly better after premedication with clonidine. Quality of mask induction was equally successful in both groups. A steal-induction was performed in 66% of patients of group C, but none in group M. We observed a trend towards an increased incidence of emergence agitation after premedication with midazolam. Parental satisfaction was significantly higher in group C. CONCLUSIONS: In this study, premedication with oral clonidine appeared to be superior to oral midazolam. Quality of mask acceptance was comparable between groups, but oral clonidine was better accepted by the child, produced more effective preoperative sedation, showed a trend towards better recovery from anesthesia and had a higher degree of parental satisfaction.     

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.     

Oral midazolam in children: effect of time and adjunctive therapy.

The purpose of this study was to determine the influence of timing and concomitant administration of atropine and/or meperidine on the perioperative effects of oral midazolam in children. In 154 healthy children, 1-8 yr old, we studied six oral preanesthetic medication regimens according to a randomized, double-blind protocol. Group A (placebo) received 5 mL of apple juice. The other five groups received medication with apple juice to a total volume of 5 mL, 20-60 min before induction of anesthesia. Group B received atropine (0.02 mg/kg); group C received midazolam (0.5 mg/kg); group D received midazolam (0.5 mg/kg) and atropine (0.02 mg/kg); group E received meperidine (1.5 mg/kg) and atropine (0.02 mg/kg); and group F received meperidine (1.5 mg/kg), atropine (0.02 mg/kg), and midazolam (0.5 mg/kg). The sedative effect of midazolam was maximal 30 min after oral administration. Ninety-five percent of the children who were separated from their parents within 45 min after oral midazolam administration (with or without atropine) had satisfactory separation scores (vs 66% of those separated after 45 min; P less than 0.02). Midazolam-treated patients were more cooperative with a mask induction of anesthesia compared with non-midazolam-treated children (83% vs 56%). Neither atropine nor meperidine appeared to significantly improve the effectiveness of oral midazolam. No preoperative changes in heart rate, respiratory rate, or hemoglobin oxygen saturation were noted in any of the treatment groups. Finally, oral midazolam did not prolong recovery even after outpatient procedures lasting less than 30 min. In conclusion, midazolam (0.5 mg/kg) given orally 30-45 min before induction of anesthesia is safe and effective without delaying recovery after ambulatory surgery.     

Oral transmucosal fentanyl citrate for preanesthetic medication of pediatric day surgery patients with and without droperidol as a prophylactic anti-emetic.

he safety and efficacy of oral transmucosal fentanyl citrate (OTFC) as a preanesthetic medication and the efficacy of droperidol as a prophylactic anti-emetic were evaluated in 100 children aged 2-8 yr undergoing general anesthesia for outpatient surgery. Patients were randomly assigned to one of four groups and managed in a double-blinded manner: 1) placebo lozenge 45 min preoperatively and placebo (normal saline) injected intravenously after induction of anesthesia; 2) placebo lozenge 45 min preoperatively and 50 micrograms/kg droperidol intravenously after induction; 3) 15-20 micrograms/kg OTFC lozenge 45 min preoperatively and placebo intravenously after induction; and 4) 15-20 micrograms/kg OTFC lozenge 45 min preoperatively and droperidol 50 micrograms/kg intravenously after induction. Anesthesia was induced and maintained with halothane and nitrous oxide in oxygen. Heart rate, respiratory rate, blood pressure, and hemoglobin oxygen saturation (SpO2) were monitored throughout the study. Scoring systems were used to evaluate sedation, anxiety, cooperation, and ease and quality of anesthetic induction. Emergence, recovery, and discharge times were recorded. Nausea, vomiting, and adverse effects were noted. Preoperatively, children receiving OTFC had significantly greater sedation, slower respiratory rates, lower SpO2, and less excitement during induction. Postoperative nausea and vomiting occurred significantly more frequently after OTFC than after placebo. Prophylactic droperidol did not significantly reduce the incidence of nausea and vomiting. The authors conclude that, in pediatric surgical outpatients, OTFC reliably induces preoperative sedation and facilitates inhalation induction of anesthesia, but it is associated with significant decreases in respiratory rate and SpO2 and a high incidence of postoperative nausea and vomiting that is not significantly reduced by prophylactic droperidol.     

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.     

Oral midazolam preanesthetic medication in pediatric outpatients

A need exists for a safe and effective oral preanesthetic medication for use in children undergoing elective surgical procedures. We evaluated the effectiveness of three different doses of oral midazolam when administered in combination with atropine prior to ambulatory surgery. In this randomized, double-blind, placebo-controlled study, 124 children, ages 1-10 yr, received midazolam, 0.25, 0.50, or 0.75 mg.kg-1 po, and atropine, 0.03 mg.kg-1 po, mixed with apple juice, or a placebo (containing the midazolam vehicle, atropine, and apple juice). A blinded observer noted the child's level of sedation, the quality of separation from parents, and the degree of cooperation with an inhalation induction of anesthesia. Picture-recall was used to assess the amnesic effect of midazolam in children over 5 yr of age. Midazolam 0.75 mg.kg-1 produced significant sedation at 30 min. After procedures lasting an average of 106-113 min, recovery was not prolonged by the oral midazolam-atropine combination. We concluded that oral midazolam 0.5-0.75 mg.kg-1 is an effective preanesthetic medication for pediatric outpatients.     

Preanesthetic medication in children: a comparison of oral transmucosal fentanyl citrate versus placebo

Initial studies have suggested that oral transmucosal fentanyl citrate (OTFC) in a dose of 15-20 micrograms/kg may be a safe and effective preanesthetic medication in children and adults, but this has not been demonstrated in a randomized, double-blind fashion. The purpose of this study was to determine in a randomized, double-blind manner, the efficacy of a lollipop containing fentanyl citrate as a preanesthetic medication before surgery in children. Forty health ASA physical status 1 or 2 children 3-12 yr of age were divided randomly and in double-blind fashion into two groups. Group 1 received the lollipop containing OTFC and group 2 received a placebo lollipop. An appropriate size lollipop was chosen so that if the patient received fentanyl, the total dose would be 15-20 micrograms/kg. Anxiety, sedation, and separation scores were assessed preoperatively and ease of induction was rated. Oxygen saturation and respiratory rate were monitored. Time intervals from preanesthetic to induction and from recovery room (PACU) admission to discharge were noted. Recovery room behavior was assessed upon admission and discharge. Complications and the need for postoperative opioids were noted. OTFC produced significantly more sedation and less anxiety compared with that following placebo. Respiratory rate was significantly decreased in the OTFC group, but oxygen saturation was not significantly different between groups. Anxiety and separation scores and the quality of induction were better in the OTFC group. There was a higher incidence of nausea and pruritus in the fentanyl group. OTFC did not prolong the PACU stay.     

Preoperative oral antiemetics for reducing postoperative vomiting after tonsillectomy in children: granisetron versus perphenazine.

In a prospective, randomized, double-blinded trial, we evaluated the efficacy of two antiemetics given orally, granisetron and perphenazine, for preventing postoperative vomiting after tonsillectomy with or without adenoidectomy in children. One hundred pediatric patients, ASA physical status I, aged 4-10 yr, received either granisetron 40 microg/kg or perphenazine 70 microg/kg (n = 50 each) orally 1 h before surgery. We used a standard general anesthetic technique. The rate of complete response, defined as no emesis and no need for rescue antiemetic medication, during 0-3 h after anesthesia was 86% with granisetron and 60% with perphenazine; the corresponding rate 3-24 h after anesthesia was 86% and 62%, respectively (P < 0.05). No serious adverse events were observed in any of the groups. In conclusion, preoperative oral granisetron is more effective than perphenazine for preventing postoperative vomiting in children undergoing tonsillectomy with or without adenoidectomy. IMPLICATIONS: We compared the efficacy of granisetron and perphenazine given orally for preventing postoperative vomiting after tonsillectomy with or without adenoidectomy in children. Preoperative oral granisetron was more effective than perphenazine.     

Clonidine vs. midazolam as premedication in children undergoing adeno-tonsillectomy: a prospective, randomized, controlled clinical trial

BACKGROUND: Clonidine administration in the setting of paediatric anaesthesia is associated with a number of desirable effects, e.g. preoperative sedation, analgesia and reduced anaesthetic requirements. The aim of the current study was to compare postoperative outcome variables using a prospective, randomized, double-blind design after premedication with clonidine or midazolam. METHODS: One hundred paediatric ASA physical status 1 patients (age 1-11 year) scheduled for adeno-tonsillectomy were assigned to receive rectal premedication with midazolam (300 microg kg(-1) and atropine 40 microg kg(-1); group M, n = 52) or clonidine (5 microg kg(-1 and) atropine 40 microg kg(-1); group C, n = 48) prior to a standardized sevoflurane anaesthetic. The incidence of immediate postoperative pain (0-2 h), as assessed by repeated Objective Pain Scale (OPS) scores, was chosen as the primary end-point of the study. Degree of sedation (modified Vancouver sedation scale 0-3), occurrence of postoperative vomiting (POV), and incidence of shivering and immediate postoperative confusion were registered as secondary end-points. After hospital discharge parents were instructed to continue the evaluation of pain, sedation, POV and sleep pattern during a 24-h period. Parents were also asked for their preference concerning the postoperative behaviour of their child (calm, sedated vs. alert, active). RESULTS: In the early postoperative period patients in the clonidine group had a significantly lower sum of 5 OPS scores (median = 8.0) compared to group M (median = 11.5) (P = 0.011). Administration of clonidine was also associated with a slightly higher sum of sedation scores (median = 13) in the early postoperative period compared to children receiving midazolam (median = 12) (P < 0.001). No episode of shivering was observed in the clonidine group but was present in five of the patients in the midazolam group (P = 0.057). In younger children (< 5 years) the incidence of postoperative confusion was lower in the clonidine group (P = 0.001). No difference in the frequencies of POV incidences, degree of postoperative pain, need for analgesics, or sleep pattern during the first 24 postoperative hours could be observed between the groups according to the parental evaluation. Children premedicated with clonidine were more calm and sedated compared to children in the midazolam group (P = 0.024) as judged by their parents. A significant majority of parents (75%; P < 0.001) preferred a calm and sedated child during the first postoperative 24-h period. CONCLUSION: Rectal premedication with clonidine was associated with a significant reduction of pain in the early postoperative period compared to midazolam and was also associated with moderately increased sedation during the first 24 postoperative hours. The sedative effect of clonidine is in agreement with the unambiguous finding of a parental preference for a calm and sedated child during the first 24 postoperative hours.     

A comparison of three doses of a commercially prepared oral midazolam syrup in children.

Midazolam is widely used as a preanesthetic medication for children. Prior studies have used extemporaneous formulations to disguise the bitter taste of IV midazolam and to improve patient acceptance, but with unknown bioavailability. In this prospective, randomized, double-blinded study we examined the efficacy, safety, and taste acceptability of three doses (0.25, 0.5, and 1.0 mg/kg, up to a maximum of 20 mg) of commercially prepared Versed((R)) syrup (midazolam HCl) in children stratified by age (6 mo to <2 yr, 2 to <6 yr, and 6 to <16 yr). All children were ASA class I-III scheduled for elective surgery. Subjects were continuously observed and monitored with pulse oximetry. Ninety-five percent of patients accepted the syrup, and 97% demonstrated satisfactory sedation before induction. There was an apparent relationship between dose and onset of sedation and anxiolysis (P < 0.01). Eight-eight percent had satisfactory anxiety ratings at the time of attempted separation from parents, and 86% had satisfactory anxiety ratings at face mask application. The youngest age group recovered earlier than the two older age groups (P < 0.001). There was no relationship between midazolam dose and duration of postanesthesia care unit stay. Before induction, there were no episodes of desaturation, but there were two episodes of nausea and three episodes of emesis. At the time of induction, during anesthesia, and in the postanesthesia care unit, there were several adverse respiratory events. Oral midazolam syrup is effective for producing sedation and anxiolysis at a dose of 0.25 mg/kg, with minimal effects on respiration and oxygen saturation even when administered at doses as large as 1.0 mg/kg (maximum, 20 mg) as the sole sedating medication to healthy children in a supervised clinical setting. IMPLICATIONS: Commercially prepared oral midazolam syrup is effective in producing sedation and anxiolysis in doses as small as 0.25 mg/kg; there is a slightly faster onset with increasing the dose to 1.0 mg/kg. At all doses, 97% of patients demonstrated satisfactory sedation, whereas 86% demonstrated satisfactory anxiolysis when the face mask was applied.     

A comparison of oral transmucosal fentanyl and oral midazolam for premedication in children

Oral transmucosal fentanyl citrate (OTF) was compared with midazolam as a premedicant in a prospective, randomised, placebo-controlled, double-blind trial. Eighty children (ASA grade 1 or 2, aged 3-9 years) who presented for tonsillectomy were randomly allocated to receive either 2.5 ml OTF (15-20 microg.kg(-1)) in a lollipop format and 0.5 ml.kg(-1) placebo syrup, or midazolam syrup (0.5 mg.kg(-1)) and a placebo lollipop (2.5 ml). The acceptability of sedation, anxiety and compliance with anaesthetic induction were assessed. The children were given an 'emergence' score for their recovery. Analgesia requirements, the incidence of vomiting, itching and any behavioural changes were assessed for 6 h postoperatively. Oral transmucosal fentanyl citrate was as effective as midazolam in aiding compliance with anaesthesia, but is significantly better in its appeal to children (p < 0.001) and emergence (p < 0.001) characteristics. In conclusion, OTF may be particularly useful as a premedicant in paediatric practice.     

Clonidine decreases intraoperative bleeding in middle ear microsurgery

BACKGROUND: The antihypertensive drug clonidine is a centrally acting alpha2 agonist useful as a premedicant because of its sedative, anxiolytic, and analgesic properties. We examined the effect of clonidine given as an oral preanesthetic medication in producing a bloodless surgical field in patients undergoing middle ear microsurgery. We also evaluated whether the administration of clonidine would alter the reflex cardiovascular response to laryngoscopy and endotracheal intubation, anesthetic requirement, postoperative pain intensity and consumption of analgesics, and pre- and postoperative sedation and anxiety. METHODS: A prospective, randomized, double-blind clinical trial was performed in 40 patients scheduled for elective middle ear surgery under general anesthesia. Twenty-one patients received clonidine (300 microg p.o.) 90 min prior to arrival at the operating theater and 19 received placebo (control group). The hemodynamic endpoint of the anesthetic management was maintenance of hypotension for producing a bloodless surgical field. The desired control of the cardiovascular system was attained with isoflurane (inspired concentration increments of 0.25 vol% up to a maximum of 1.5 vol%)+/-fentanyl (bolus of 1 microg. kg-1)+/-urapidil (bolus of 0.3 mg. kg-1) as needed. Intraoperative bleeding was assessed on a four-point scale from 0=no bleeding to 3=abundant bleeding. RESULTS: There was less bleeding in the clonidine group (mean+/-SEM) than in the control group (0.75+/-0.3 vs 1.1+/-0.4, P<0.05). Patients given clonidine required a mean inspired isoflurane concentration of 0.63+/-0.1 vol% as compared with 1.01+/-0.2 vol% in controls (P<0.05). Fentanyl requirements were also significantly lower (57.10 vs 79.42 microg. kg-1, P<0.05). Four clonidine-treated patients required urapidil to achieve satisfactory hypotension as compared with 11 controls (P<0.05). Clonidine attenuated the associated cardiovascular response following laryngoscopy and intubation, and was more effective than placebo in achieving a satisfactory preoperative sedation and decreasing intensity of postoperative pain. Preoperative anxiety and incidence of adverse events was similar in both groups. CONCLUSION: Premedication with clonidine reduced bleeding in middle ear microsurgery, attenuated hyperdynamic response to tracheal intubation, and reduced isoflurane, fentanyl, and urapidil requirements for controlled hypotension.     

Oral clonidine reduces the requirement of prostaglandin El for induced hypotension

PURPOSE: To determine the effects of preanesthetic oral clonidine on the dose of prostaglandin EI (PGEI) required to produce hypotension during anesthesia. METHOD: Oral placebo, 75 microg or 150 microg clonidine were administered 60 min prior to induction of anesthesia. Anesthesia was maintained with O2:N2O (30:70) and isoflurane 1.0%. After hemodynamic stabilization, an infusion of prostaglandin EI was started (0.05 microg x kg(-1) x min(-1)) and the rate of infusion was adjusted to maintain mean arterial pressure (MAP) between 60-70 mm Hg during operation. RESULTS: Duration of hypotension in placebo, 75 microg and 150 microg preanesthetic oral clonidine treated groups were 132+/-46, 117+/-37 and 129+/-56 min, respectively. The PGEI requirement in each group were 1563+/-180 (28.6+/-3.2), 594+/-197 (10.8+/-3.6) and 283+/-30 (5.5+/-3.6) microg (microg x kg(-1)), respectively. In addition, blood loss in each group were 1461+/-389, 805+/-240 and 931+/-40 ml, respectively. CONCLUSION: Preanesthetic oral clonidine decreased the dose of PGEI required to produce hypotension, and decreased the blood loss during operation.     

Postoperative behavioral outcomes in children: effects of sedative premedication

BACKGROUND: Although multiple studies document the effect of sedative premedication on preoperative anxiety in children, there is a paucity of data regarding its effect on postoperative behavioral outcomes. METHODS: After screening for recent stressful life events, children undergoing anesthesia and surgery were assigned randomly to receive either 0.5 mg/kg midazolam in 15 mg/kg acetaminophen orally (n = 43) or 15 mg/kg acetaminophen orally (n = 43). Using validated measures of anxiety, children were evaluated before and after administration of the intervention and during induction of anesthesia. On postoperative days 1, 2, 3, 7, and 14, the behavioral recovery of the children was assessed using the Post Hospitalization Behavior Questionnaire. RESULTS: The intervention group demonstrated significantly lower anxiety levels compared with the placebo group on separation to the operating room and during induction of anesthesia (F[1,77] = 3.95, P = 0.041). Using a multivariate logistic regression model, the authors found that the presence or absence of postoperative behavioral changes was dependent on the group assignment (R = 0.18, P = 0.0001) and days after operation (R = -0.20, P = 0.0001). Post hoc analysis demonstrated that during postoperative days 1-7, a significantly smaller number of children in the midazolam group manifested negative behavioral changes. At week 2 postoperatively, however, there were no significant differences between the midazolam and placebo groups. CONCLUSIONS: Children who are premedicated with midazolam before surgery have fewer negative behavioral changes during the first postoperative week.     

Postoperative Behavioral Outcomes in Children: Effects of Sedative Premedication

Background: Although multiple studies document the effect of sedative premedication on preoperative anxiety in children, there is a paucity of data regarding its effect on postoperative behavioral outcomes.

Methods: After screening for recent stressful life events, children undergoing anesthesia and surgery were assigned randomly to receive either 0.5 mg/kg midazolam in 15 mg/kg acetaminophen orally (n = 43) or 15 mg/kg acetaminophen orally (n = 43). Using validated measures of anxiety, children were evaluated before and after administration of the intervention and during induction of anesthesia. On postoperative days 1, 2, 3, 7, and 14, the behavioral recovery of the children was assessed using the Post Hospitalization Behavior Questionnaire.

Results: The intervention group demonstrated significantly lower anxiety levels compared with the placebo group on separation to the operating room and during induction of anesthesia (F[1,77] = 3.95, P = 0.041). Using a multivariate logistic regression model, the authors found that the presence or absence of postoperative behavioral changes was dependent on the group assignment (R = 0.18, P = 0.0001) and days after operation (R = -0.20, P = 0.0001). Post hoc analysis demonstrated that during postoperative days 1-7, a significantly smaller number of children in the midazolam group manifested negative behavioral changes. At week 2 postoperatively, however, there were no significant differences between the midazolam and placebo groups.     

术前口服咪达唑仑对患儿七氟醚麻醉苏醒期躁动的影响

目的评价术前口服咪达唑仑对患儿七氟醚麻醉苏醒期躁动的影响。方法选择择期七氟醚麻醉下行扁桃体/腺样体切除术的患儿60例,男34例,女26例,年龄2~7岁,ASAⅠ或Ⅱ级,将入选患儿随机分为低剂量咪达唑仑组(M1组)、高剂量咪达唑仑组(M2组)和对照组(C组),每组20例。麻醉前30min分别给予M1组和M2组患儿分别口服咪达唑仑0.5 mg/kg和0.75 mg/kg,口服10%葡萄糖混合液5ml。吸入8%七氟醚行麻醉诱导,术中吸入七氟醚及静脉泵注瑞芬太尼维持麻醉。记录患儿分离焦虑量表(PSAS)评分、麻醉苏醒谵妄量表(PAED)评分和FLACC疼痛评分,并记录拔除气管导管时间和滞留PACU时间。结果 C组患儿的分离焦虑发生率明显高于其他两组(P0.05)。三组苏醒期躁动发生率、最高PAED评分、FLACC疼痛评分以及拔除气管导管时间差异均无统计学意义。M2组滞留PACU时间明显长于其他两组(P0.05)。结论术前口服咪达唑仑0.5mg/kg或0.75mg/kg能有效减轻患儿术前分离焦虑,但不能减少七氟醚麻醉苏醒期躁动的发生,咪达唑仑0.75mg/kg会延长PACU滞留时间。     

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.     

Comparative evaluation of midazolam and ketamine with midazolam alone as oral premedication

BACKGROUND: Oral premedication with midazolam and ketamine is widely used in pediatric anesthesia to reduce emotional trauma and ensure smooth induction. However, various dosing regimens when used alone or in combination have variable efficacy and side effect profile. The aim of our study was to investigate and compare the efficacy of oral midazolam alone with a low-dose combination of oral midazolam and ketamine. METHODS: We performed a prospective randomized double-blind study in 100 children who were randomly allocated into two groups. Group M received 0.5 mg.kg(-1) oral midazolam and group MK received 0.25 mg.kg(-1) oral midazolam with 2.5 mg.kg(-1) oral ketamine. The preoperative sedation score, ease of parental separation and ease of mask acceptance were evaluated on a 4-point scale. The time to recovery from anesthesia and to achieve satisfactory Aldrete score was also noted. RESULTS: Uniform and acceptable sedation scores were seen in both the groups (group M 95.9%; group MK 97.96%), without any serious side effects. However, the combination offered significantly more children in an awake, calm and quiet state, who were easily separated from their parents (73.46% in MK vs 41% in group M). The induction scores were comparable between the groups. The recovery room characteristics and time to achieve satisfactory Aldrete score were also comparable between the two groups. CONCLUSIONS: Oral midazolam alone and a combination of midazolam with ketamine provide equally effective anxiolysis and separation characteristics. However, the combination provided more children in an awake, calm and quiet state who could be separated easily from parents.     

The effects of preanesthetic oral clonidine on total requirement of propofol for general anesthesia

Study Objective: To investigate the effects of preanesthetic oral clonidine on total propofol requirement for uniform minor surgery (breast conservative surgery: breast cancer removal with axillary lymph node dissection), and to compare the action of clonidine with that of preanesthetic oral diazepam, a commonly used benzodiazepine.

Design: Randomized double-blinded study.

Setting: Operating room ASA physical status I and II room and recovery room of the cancer center.

Patients: 80 breast cancer patients scheduled for surgery.

Interventions: Patients were randomized to one of four treatment groups (placebo, clonidine 75 μg, or 150 μg of clonidine, or 10 mg of diazepam were orally administered 60 min before induction of anesthesia); n = 20 per group. After evaluating the sedation and anxiety levels of patients using a visual analog scale, anesthesia was induced with propofol (1.5 mg/kg), and maintained with oxygen (O₂): nitrous oxide (N₂O) (30:70) with a continuous infusion of propofol. The propofol infusion was started at 10 mg/kg/h for 10 minutes, then decreased to 8 mg/kg/h, and 6 mg/kg/h thereafter, and the rate of infusion was adjusted to obtain adequate anesthesia (maintaining hemodynamic parameters within 20% of that prior to premedication). Fentanyl 0.2 mg (each 0.1 mg was given for intubation and axillary lymph node dissection, respectively) was administered.

Measurements and Main Results: Preanesthetic oral clonidine (150 μg) and diazepam (10 mg) induced anxiolysis without sedation. The total requirement (the mean infusion rates) of propofol in placebo, clonidine 75 μg, clonidine 150 μg, and 10 mg of diazepam groups were 841 ± 70 (9.0 ± 0.3), 720 ± 63 (7.1 ± 0.4), 491 ± 39 (5.6 ± 0.2), and 829 ± 77 mg (7.9 ± 0.4 mg/kg/h), respectively. The cost of propofol in these groups was $51.0 ± 3.8, $45.5 ± 3.2, $33.5 ± 2.3, and $50.5 ± 4.4, respectively.

Conclusions: Preanesthetic oral clonidine (150 μg) but not diazepam (10 mg) reduced the total requirement of propofol while stabilizing hemodynamic parameters. In addition, 150 μg of oral clonidine attenuates the hemodynamic responses associated with tracheal intubation.     

Clonidine prevents sevoflurane-induced agitation in children

In a double-blinded trial, 40 male children (age 2-7 yr) undergoing circumcision were randomly assigned to receive clonidine 2 microg/kg IV or placebo after anesthetic induction. For induction and maintenance of anesthesia, we used sevoflurane as the sole anesthetic. For pain treatment, a penile block was performed before surgery. After surgery the incidence and severity of agitation was measured during an observation period of 2 h. Severe agitation was treated with midazolam. In 16 placebo and 2 clonidine-treated patients agitation was observed (P < 0.001). In 6 patients of the Placebo group, agitation was graded as severe, whereas none of the patients in the Clonidine group developed severe agitation (P = 0.02). During the postoperative period heart rate and blood pressure were significantly decreased in clonidine treated patients (P < 0.05). We conclude that clonidine effectively prevents agitation after sevoflurane anesthesia. IMPLICATIONS: The recovery from sevoflurane anesthesia may be complicated by the presence of agitation in pediatric patients. Clonidine 2 microg/kg IV after anesthetic induction effectively reduces the incidence of agitation without resulting in clinically relevant bradycardia and hypotension.