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.     

Propofol sedation with fentanyl or midazolam during oesophagogastroduodenoscopy in children

BACKGROUND AND OBJECTIVE: Sedation is commonly used to facilitate diagnostic procedures in children. The aim of our study was to investigate sedation in children using propofol alone or combined with fentanyl or midazolam with regard to efficacy, adverse reactions or side-effects related to the drugs, ease of operation for the endoscopist, and time to discharge from the post-anaesthesia care unit. METHODS: We prospectively studied 240 children, aged 1-12 yr of age, undergoing endoscopic procedures of the upper gastrointestinal tract. The patients were given an oral premedication with midazolam (0.5 mg kg(-1)) and were then randomly allocated to one of the three study groups: propofol alone (Group P), propofol with fentanyl 1 mug kg-1 (Group PF) or propofol with midazolam 0.1 mg kg(-1) (Group PM). Additional doses of propofol given during the procedure were recorded. Adequacy of sedation and ease of procedure (easy, adequate, impossible) were evaluated by the endoscopist, who was blinded as to the drugs used. RESULTS: The duration of the procedure and the recovery period were similar in the three groups. The number of patients requiring supplemental doses of propofol to permit safe completion of gastroscopy was 31 in Group P (=39%; eight of these required two additional doses), 14 in Group PM (=18%), and 11 in Group PF (=13%) (P < 0.05). There was a lower incidence of adverse events in Group PM and in Group PF than in Group P (P < 0.05). CONCLUSIONS: Propofol in combination with fentanyl or midazolam gives better sedation and ease of endoscopy than propofol alone.     

Pentobarbital vs chloral hydrate for sedation of children undergoing MRI: efficacy and recovery characteristics

BACKGROUND: Chloral hydrate (CH) sedation for magnetic resonance imaging (MRI) is associated with significant failure rates, adverse events and delayed recovery. Pentobarbital (PB), reportedly produces successful sedation in 98% of children undergoing diagnostic imaging. This study compared the efficacy, adverse events and recovery characteristics of CH vs PB in children undergoing MRI. METHODS: With Institutional Review Board approval and written consent, children were randomly assigned to receive intravenous (i.v.) PB (maximum 5 mg x kg(-1) in incremental doses) or oral CH (75 mg x kg(-1)) prior to MRI. Sedation was augmented with 0.05 mg x kg(-1) doses of i.v. midazolam (maximum 0.1 mg x kg(-1)) as necessary. Adverse effects, including hypoxaemia, failed sedation, paradoxical reactions and behavioural changes, the return of baseline activity, and parental satisfaction were documented. The quality of MRI scans was evaluated by a radiologist blinded to the sedation technique. RESULTS: PB facilitated an earlier onset of sedation (P = 0.001), higher sedation scores (P = 0.01), and less need for supplemental midazolam compared with CH. Severe hypoxaemia occurred in two children (6%) in the PB group. Fourteen per cent of the PB group experienced a paradoxical reaction, 9% sedation failure and 11% major motion artefact, compared with 0% (P = 0.05), 3 and 2% (P = NS), respectively, in the CH group. CH and PB were both associated with a high incidence of motor imbalance, and agitation. However, children who received PB had a slower return to baseline activity (P = 0.04). CONCLUSIONS: Although PB facilitated a quicker sedation onset and reduced the requirement for supplemental sedation, it produced a higher incidence of paradoxical reaction and prolonged recovery with a similar failure rate compared with CH.     

Oral high-dose midazolam premedication for infants and children undergoing cardiovascular surgery

BACKGROUND: The purpose of this study was to determine whether oral midazolam 1.5 mg x kg(-1) is a safe and effective alternative to standard-dose midazolam (0.5-1.0 mg x kg(-1)) premedication for infants and children with congenital heart disease. METHODS: A total of 193 infants and children (4 months to 2 years) undergoing cardiovascular surgery were studied. Each patient received 0.5, 1.0, or 1.5 mg x kg(-1) of oral midazolam. The level of sedation was assessed with a 5-point scale and vital signs were measured including blood pressure (BP), heart rate (HR) and oxyhaemoglobin saturation (SpO2) before and after the medication. RESULTS: Infants and children premedicated with oral midazolam 1.5 mg x kg(-1) were better sedated than those with standard-dose midazolam: 4% of infants and children given 1.5 mg x kg(-1) of midazolam became agitated compared with 14% given 1.0 mg x kg(-1) and 26% in those given 0.5 mg x kg(-1). Ninety percentage of infants and children given 1.5 mg x kg(-1) of midazolam achieved satisfactory sedation (calm, drowsy, or asleep) in 30 min, whereas 68% in those given 1.0 mg x kg(-1) and 35% in those given 0.5 mg x kg(-1). Midazolam 1.5 mg x kg(-1) did not cause any statistically significant decrease in BP, HR, or SpO2, although eight infants and children showed > or =20% drop in systolic BP and six infants and children showed >5% drop in SpO2. No 'spelling attacks', seizure-like activity, apnoea, nor laryngospasm were observed in any infants and children during and after the medication. CONCLUSIONS: Oral midazolam 1.5 mg x kg(-1) is excellent for preanaesthetic medication for infants and children undergoing cardiovascular surgery.     

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.     

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.     

Propofol-ketamine vs propofol-fentanyl for sedation during pediatric upper gastrointestinal endoscopy

BACKGROUND: The aim of this study was to compare the clinical efficacy and safety of propofol-ketamine with propofol-fentanyl in pediatric patients undergoing diagnostic upper gastrointestinal endoscopy (UGIE). METHODS: This was a prospective, randomized, double blinded comparison of propofol-ketamine with propofol-fentanyl for sedation in patients undergoing elective UGIE. Ninety ASA I-II, aged 1 to 16-year-old patients were included in the study. Heart rate (HR), systolic arterial pressure, peripheral oxygen saturation, respiratory rate (RR) and Ramsey sedation scores of all patients were recorded perioperatively. Patients were randomly assigned to receive either propofol-ketamine (PK; n = 46) or propofol-fentanyl (PF; n = 44). PK group received 1 mg x kg(-1) ketamine + 1.2 mg x kg(-1) propofol, and PF group received 1 microg x kg(-1) fentanyl + 1.2 mg x kg(-1) propofol for sedation induction. Additional propofol (0.5-1 mg x kg(-1)) was administered when a patient showed discomfort in either group. RESULTS: The number of patients who needed additional propofol in the first minute after sedation induction was eight in Group PK (17%), and 22 in Group PF (50%) (P < 0.01) and those who did not need additional propofol throughout the endoscopy were 14 in Group PK (30%) and three in Group PF (7%) (P < 0.01). HR and RR values after induction in Group PF were significantly lower than Group PK (P < 0.01). CONCLUSIONS: Both PK and PF combinations provided effective sedation in pediatric patients undergoing UGIE, but the PK combination resulted in stable hemodynamics and deeper sedation though more side effects.     

The use of midazolam and small-dose ketamine for sedation and analgesia during local anesthesia.

Small-dose ketamine in combination with sedative drugs has increasingly been used for sedation and analgesia in local anesthesia. We compared the clinical efficacy of midazolam with two different ketamine infusion regimens during plastic surgery under local anesthesia. Sixty patients undergoing plastic surgery procedures with local anesthesia were randomly assigned to two groups of 30 patients each in a double-blinded fashion. All patients received a bolus of 0.05 mg/kg midazolam, followed by a stepwise infusion: 1.67 microg x kg(-1) x min(-1) for the first 30 min, then reduced to 1.33 microg x kg(-1) x min(-1) for 90 min and subsequently to 1 microg x kg(-1) x min(-1). Two minutes before the infiltration of local anesthetic solution, a bolus of ketamine 0.3 mg/kg IV was administered, followed by a stepwise infusion of ketamine: Group A, 16.67 microg x kg(-1) x min(-1) for 30 min, 13.3 microg x kg(-1) x min(-1) for 90 min, and subsequently 10 microg x kg(-1) x min(-1); Group B, 8.33 microg x kg(-1) x min(-1) for 30 min, 6.67 microg x kg(-1) x min(-1) for 90 min, and then 5 microg x kg(-1) x min(-1). The level of sedation was evaluated by using the modified Observer's Assessment of Alertness/Sedation scale. We observed the effects of the two ketamine infusion regimens on sedation levels, respiratory and cardiovascular variables, and perioperative side effects. In both groups, midazolam and ketamine produced adequate sedation (with Observer's Assessment of Alertness/Sedation scores of 2-4) without significant respiratory and cardiovascular depression during surgery. However, there were fewer disruptive movements and there was less postoperative vomiting in Group B (P < 0.01). In conclusion, ketamine and midazolam provided satisfactory intraoperative sedation, analgesia, and amnesia in both groups. However, side effects associated with ketamine occurred less often in the smaller-dose ketamine group. IMPLICATIONS: Sedation and analgesia are often provided during local anesthesia. This study demonstrates that a small-dose ketamine infusion in combination with midazolam provided satisfactory intraoperative sedation, analgesia, and amnesia in healthy plastic-surgery patients when it was used to supplement local anesthesia.     

Hyperbaric bupivacaine affects the doses of midazolam required for sedation after spinal anaesthesia

BACKGROUND AND OBJECTIVE: Patients having spinal anaesthesia with hyperbaric bupivacaine may become sensitive to sedative drugs but no data exists about any dose-related effect of the local anaesthetic on the sedative requirement. We aimed to investigate whether hyperbaric bupivacaine dose in spinal anaesthesia has any effect on midazolam requirements. METHODS: Sixty unpremedicated patients were allocated to three equal groups. Patients in Groups I and II received hyperbaric bupivacaine 0.5% 10 and 17.5 mg respectively for spinal anaesthesia and Group III was a control group without spinal anaesthesia. In Groups I and II, after the evaluation of sensory block, patients received intravenous midazolam 1 mg per 30 s until the Ramsay sedation score reached 3 (drowsy but responsive to command). In Group III, general anaesthesia was induced after sedation score had reached 3 using midazolam. The total dose of midazolam (mg kg(-1)) given to each patient, the level of sensory block and complications were recorded. RESULTS: The level of sensory block was higher in Group II (T7) than Group I (T9) (P < 0.01). The doses of midazolam were 0.063 mg kg(-1) in Group I, 0.065 mg kg(-1) in Group II and 0.101 mg kg(-1) in Group III (P < 0.001). There was no correlation between level of sensory block and dose of midazolam in Group I (r = -0.293, P = 0.21) and Group II (r = 0.204, P = 0.39). CONCLUSIONS: Different doses of hyperbaric bupivacaine for spinal anaesthesia do not affect the midazolam requirements for sedation. However, spinal anaesthesia with hyperbaric bupivacaine with a maximum spread in the middle thoracic dermatomes may be associated with sedative effects and thus a reduced need for further sedation with midazolam.     

Oral midazolam premedication for children with congenital cyanotic heart disease under-going cardiac surgery: a comparative study

To determine whether oral midazolam is a safe and effective alternative to our current standard premedication for children with cyanotic congenital heart disease (CCHD), 30 children aged 1–6 yr, scheduled for elective cardiac surgery, were studied. The children were randomly assigned to one of two groups: Group I received oral midazolam 0.75 mg · kg^{? 1} 30 min before separation from their parents in the surgical waiting area, and Group II received oral or rectal pentobarbitone 2 mg · kg^{? 1} at 90 min, and morphine 0.2 mg· kg^{? 1} and atropine 0.02 mg· kg^{? 1} im at 60 min before separation. Heart rate, haemoglobin oxygen saturation (SpO₂) and anxiolysis and sedation scores were recorded at four times during the study: at baseline (immediately before premedication), immediately after administration of the premedication, at separation of children from parents in the waiting area and at the time of application of the face mask in the operating room. We found that in Group I, anxiolysis improved at separation from parents compared with baseline (P < 0.05) and sedation increased both at separation and on mask application (P < 0.05), whereas in Group II anxiolysis did not change at any time and sedation increased only at separation (P < 0.05). Intramuscular injection of morphine produced a transient decrease in mean SpO₂ (from 84% to 76%) (P < 0.05) that did not occur after ingestion of oral midazolam. The results of this study indicate that oral midazolam is a safe and effective replacement for the standard premedication for children with CCHD undergoing cardiac surgery and avoids the decrease in SpO₂ associated with im injections.     

A comparison of midazolam, alfentanil and propofol for sedation in oupatient intraocular surgery

PURPOSE: To determine the ideal sedative regimen for intraocular surgery under peribulbar or retrobulbar block. The addition of alfentanil and or propofol to midazolam was evaluated with regard to hemodynamic variables, respiratory rate, pain, anxiety, sedation, postoperative recovery and patient satisfaction. METHODS: Eighty two patients aged between 50 and 85 were recruited into this prospective, randomised, double blind study. Patients, in four groups, received 0.015 mg x kg(-1) midazolam, 5 microg x kg(-1) alfentanil and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 5 microg x kg(-1) alfentanil or 0.015 mg x kg(-1) midazolam alone. Blood pressure, heart rate, respiratory rate, pain, anxiety and sedation scores were measured. Times to discharge from the Post Anesthesia Care Unit (PACU) and Day Surgery Unit (DSU) were documented. A 24 hr telephone interview was carried out to determine patient satisfaction. RESULT: Systolic blood pressure of patients in groups that had received alfentanil was 6% lower than that of patients who had not (P<0.05) at the time of insertion of intraocular block. Patients in the alfentanil groups also had lower respiratory rates during the first 15 min after drug administration, but all patients were given supplemental oxygen therefore oxygen saturation was unaffected. Pain scores of patients who had been given alfentanil were lower during the first postoperative hour than those who had not. CONCLUSION: The addition of alfentanil to midazolam is advantageous in providing sedation for insertion of intraocular block.     

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.     

Brachial plexus block with midazolam and bupivacaine improves analgesia

PURPOSE: Adjuncts to local anesthetics for brachial plexus block may enhance the quality and duration of analgesia. Midazolam, a water-soluble benzodiazepine, is known to produce antinociception and enhance the effect of local anesthetics when given epidurally or intrathecally. The purpose of this study was to assess the effect of midazolam added to brachial plexus anesthesia. METHODS: A prospective, randomized, double blind study was conducted on 40 ASA I or II adult patients undergoing upper limb surgeries under supraclavicular brachial plexus block. Patients were randomly divided into two groups. Patients in Group B (n = 20) were administered 30 mL of 0.5% bupivacaine and Group BM (n = 20) were given 30 mL of 0.5% bupivacaine with midazolam 50 microg x kg(-1). Hemodynamic variables (i.e., heart rate, noninvasive blood pressure), pain scores and rescue analgesic requirements were recorded for 24 hr postoperatively. RESULTS: The onset of sensory and motor block was significantly faster in Group BM compared to Group B (P < 0.05). Pain scores were significantly higher in Group B compared to Group BM from two hours to 24 hr postoperatively (P < 0.05). Rescue analgesic requirements were significantly less in Group BM compared to Group B (P < 0.05). Hemodynamics and sedation scores did not differ between groups in the post-operative period. CONCLUSION: Midazolam (50 microg x kg(-1)) in combination with 30 mL of bupivacaine (0.5%) hastened onset of sensory and motor block, and improved postoperative analgesia when used in brachial plexus block, without producing any adverse events.     

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.     

Reevaluation of rectal ketamine premedication in children: comparison with rectal midazolam

BACKGROUND: Results of previous studies of rectal ketamine as a pediatric premedication are clouded because of lack of dose-response relation, inappropriate time of assessing sedative effects, and previous administration or coadministration of benzodiazepines. Therefore, the authors reevaluated the efficacy of rectally administered ketamine in comparison with 1 mg/kg rectal midazolam. METHODS: Sixty-six infants and children (age, 7-61 months) who were American Society of Anesthesiologists physical status I and who were undergoing minor surgeries as in-patients were randomized to receive 5 mg/kg ketamine (n = 16), 7 mg/kg ketamine (n = 16), 10 mg/kg ketamine (n = 17), or 1 mg/kg midazolam (n = 17) via rectum. A blinded observer scored sedation 45 min and 15 min after administration of ketamine and midazolam, respectively, when children were separated from parent(s) for inhalational induction. All children underwent standardized general anesthesia with sevoflurane, nitrous oxide, and oxygen with endotracheal intubation. Blood pressure, heart rate, and oxyhemoglobin saturation were determined before, during, and after anesthesia. Postoperative recovery characteristics and incidence of adverse reactions were also assessed. RESULTS: Most children (88%) who received rectally 10 mg/kg ketamine or 1 mg/kg midazolam separated easily from their parents compared with those (31%) who received 7 or 5 mg/kg rectal ketamine (P < 0.05). Similarly, more children who received 10 mg/kg ketamine or 1 mg/kg midazolam underwent mask induction without struggling or crying compared with those who received 7 or 5 mg/kg ketamine (P < 0.05). There were no clinically significant changes in blood pressure, heart rate, and oxyhemoglobin saturation after administration of either drug. Immediately after surgery, more children receiving midazolam or 5 mg/kg ketamine were agitated compared with 7 or 10 mg/kg ketamine. Ketamine, 7 and 10 mg/kg, provided postoperative analgesia, but the largest dose of ketamine was associated with delayed emergence from general anesthesia. CONCLUSIONS: The results indicate that rectally administered ketamine alone produces dose-dependent sedative effects in children, when evaluated at its predicted peak plasma concentration. Ketamine, 10 mg/kg, has a delayed onset but is as effective as 1 mg/kg midazolam for sedating healthy children before general anesthesia. However, 10 mg/kg rectal ketamine is not recommended for brief surgeries because of prolonged postoperative sedation.     

A single dose of fentanyl and midazolam prior to Cesarean section have no adverse neontal effects

PURPOSE: Analgesia and sedation, routinely used as adjunct medications for regional anesthesia, are rarely used in the pregnant patient because of concerns about adverse neonatal effects. In an effort to obtain more information about maternal analgesia and sedation we studied neonatal and maternal effects of iv fentanyl and midazolam prior to spinal anesthesia for elective Cesarean section. METHODS: In this double-blinded, randomized, placebo-controlled trial, 60 healthy women received either a combination of 1 microg x kg(-1) fentanyl and 0.02 mg x kg(-1) midazolam intravenously or an equal volume of iv saline at the time of their skin preparation for a bupivacaine spinal anesthetic. Sample size was based on a non-parametric power analysis (power > 0.80 and alpha = 0.05) for clinically important differences in Apgar scores. Fetal outcome measures included Apgar scores, continuous pulse oximetry for three hours, and neurobehavioural scores. Maternal outcomes included catecholamine levels, and recall of anesthesia and delivery. RESULTS: There were no between-group differences of neonatal outcome variables (Apgar score, neurobehavioural scores, continuous oxygen saturation). Mothers in both groups showed no difference in their ability to recall the birth of their babies. CONCLUSIONS: Maternal analgesia and sedation with fentanyl (1 microg x kg(-1)) and midazolam (0.02 mg x kg(-1)) immediately prior to spinal anesthesia is not associated with adverse neonatal effects.     

Anaesthesia with midazolam and S-(+)-ketamine in spontaneously breathing paediatric patients during magnetic resonance imaging

We evaluated safety and efficacy of a sedation technique based on rectal and intravenous S-(+)-ketamine and midazolam to achieve immobilization during Magnetic Resonance Imaging (MRI). Thirty-four paediatric patients were randomly assigned to undergo either the sedation protocol (study group) or general anaesthesia (control group). Imaging was successfully completed in all children. Children in the study group received a rectal bolus (0.5 mg x kg(-1) midazolam and 5 mg x kg(-1) S-(+)-ketamine) and required additional i.v. supplementation (20+/-10 microg x kg(-1) x min(-1) S-(+)-ketamine and 4+/-2 microg x kg(-1) x min(-1) midazolam), spontaneous ventilation was maintained. Transient desaturation occurred once during sedation and four times in the control group (P=0.34). PECO2 was 5.3+/-0.5 kPa (40+/-4 mm Hg) in the study group and 4.1+/-0.6 kPa (31+/-5 mm Hg) in the control group (P<0.001). Induction and discharge times were shorter in the study group (P<0.001), recovery times did not differ significantly between the groups. Our study confirms that a combination of rectal and supplemental intravenous S-(+)-ketamine plus midazolam is a safe and useful alternative to general anaesthesia for MRI in selected paediatric patients.     

Premedication with midazolam delays recovery after ambulatory sevoflurane anesthesia in children.

We studied the effect of oral premedication with midazolam on the recovery characteristics of sevoflurane anesthesia in small children. In a randomized, double-blinded study, 60 children (1-3 yr, ASA physical status I or II) undergoing ambulatory adenoidectomy received either midazolam 0.5 mg/kg (Group M) or placebo (Group P) PO approximately 30 min before the induction of anesthesia. All children received atropine 0.01 mg/kg IV and alfentanil 10 microg/kg IV before the induction of anesthesia with sevoflurane up to 8 vol% inspired concentration in N2O 67% in O2. Tracheal intubation was facilitated with mivacurium 0.2 mg/kg. Anesthesia was continued with sevoflurane adjusted to maintain hemodynamic stability. In the postanesthesia care unit, predetermined recovery end points (emergence, recovery, discharge) were recorded. A pain/ discomfort scale was used to determine the quality of recovery. A postoperative questionnaire was used to evaluate the well-being of the patient at home 24 h after surgery. Emergence (spontaneous eye opening), recovery (full points on the modified Aldrete scale), and discharge were achieved later in Group M than in Group P (15+/-6 vs. 11+/-3 min [P = 0.002], 25+/-17 vs. 16+/-6 min [P = 0.01], and 80+/-23 vs. 70+/-23 min [P = 0.03]). Side effects, postanesthetic excitement, and analgesic treatment did not differ significantly between groups. At home, more children in Group P (30%) experienced disturbed sleep during the night compared with those in Group M (4%) (P = 0.007). IMPLICATIONS: In this randomized, double-blinded, placebo-controlled study, premedication with midazolam 0.5 mg/kg PO delayed recovery in children 1-3 yr of age after brief (<30 min) sevoflurane anesthesia. Except for more peaceful sleep at home, premedication did not affect the quality of recovery.     

A comparison of dexmedetomidine and midazolam for sedation in third molar surgery

This randomised, double-blind study compared dexmedetomidine and midazolam for intravenous sedation during third molar surgery under local anaesthesia. Sixty patients received either dexmedetomidine (up to 1 microg x kg(-1)) or midazolam (up to 5 mg), which was infused until the Ramsay Sedation Score was four or the maximum dose limit was reached. Intra-operative vital signs, postoperative pain scores and analgesic consumption, amnesia, and satisfaction scores for patients and surgeons, were recorded. Sedation was achieved by median (IQR (range)) doses of 47 microg (39-52 (25-76)) or 0.88 microg x kg(-1) (0.75-1.0 (0.6-1.0)) dexmedetomidine, and 3.6 mg (3.3-4.4 (1.9-5.0)) or 0.07 mg x kg(-1) (0.055-0.085 (0.017-0.12)) midazolam. Heart rate and blood pressure during surgery were lower in dexmedetomidine group. There was no significant difference in satisfaction or pain scores. Midazolam was associated with greater amnesia. Dexmedetomidine produces comparable sedation to midazolam.     

枸橼酸钠对先天性心脏病患儿咪达唑仑口服术前用药效果的影响

目的 探讨枸橼酸钠对先天性心脏病患儿咪达唑仑口服术前用药效果的影响.方法 选择拟行房缺修补术、室缺修补术或动脉导管结扎术的患儿40例,年龄2～6岁,体重12～20 kg,ASA分级Ⅱ或Ⅲ级,随机分为2组(n=20):对照组(C组)和枸橼酸钠组(S组).口服术前用药:S组为咪达唑仑0.12 ml/kg、氯胺酮0.12 ml/kg、葡萄糖0.12 ml/kg和枸橼酸钠0.12 ml/kg,等容积混合;C组为咪达唑仑0.12 ml/kg、氯胺酮0.12 ml/kg和葡萄糖0.24 ml/kg,等容积混合.用pH值1.75的盐酸模拟胃液,与两组配置好的药液在体外混合,分别测定两组混合药液的pH值.记录术前焦虑评分,口服术前药(0.48 ml/kg)后,记录咪达唑仑起效时间、镇静评分和与父母分离评分.入室后记录HR、MAP和SpO2,记录患儿对静脉穿刺反应评分和服药后的不良反应发生情况.结果 与盐酸混合后C组药物pH值为1.97,S组为4.52.两组患儿均成功口服术前药物.与C组比较,S组与父母分离评分、镇静评分和静脉穿刺反应评分降低,咪达唑仑起效时间缩短(P＜0.05),术前焦虑评分差异无统计学意义(P＞0.05);两组患儿入室时HR、MAP和SpO2均在正常范围.两组患儿在服药后均未出现恶心呕吐、呼吸抑制等不良反应.结论 作为先天性心脏病患儿口服术前用药时,枸橼酸钠可提高药液的pH值,缩短咪达唑仑起效时间,加强镇静效果.