Sevoflurane Anesthesia In Children Research Articles

Early and Late Reversal of Rocuronium with Pyridostigmine during Sevoflurane Anaesthesia in Children

This study investigated the effect of pyridostigmine administered at different levels of recovery of neuromuscular function after rocuronium during sevoflurane anaesthesia in children. Fifty-one patients aged 3 to 10 years, ASA physical status 1 or 2 were randomized to 4 groups: a spontaneous recovery group; or, reversal with pyridostigmine 0.25 mg/kg with glycopyrrolate 0.01 mg/kg at one of three times: 5 minutes after rocuronium administration; at 1% twitch height (T1) recovery; or at a 25% twitch height (T25) recovery. Anaesthesia was induced with thiopentone (5-7 mg/kg) and maintained with 2-3% sevoflurane and 50% nitrous oxide. Atropine (0.015 mg/kg) and, after calibrating the TOF-Watch, rocuronium (0.6 mg/kg) were then administered. Maximal block occurred 1.1+/-0.5 min (mean, SD) after rocuronium administration. In the spontaneous recovery group, the clinical duration (recovery to T25) was 40.1+/-8.8 min and the recovery index (time between T25 and T75) 19.9+/-9.8 min. Recovery to TOF >0.9 from the time of rocuronium administration was reduced by approximately 30% in the pyridostigmine groups compared to the spontaneous recovery group. There was no significant difference among the three pyridostigmine groups. When pyridostigmine was given at T1 or T25, the time from pyridostigmine administration to TOF >0.9 was shorter than for the group receiving pyridostigmine 5 minutes after rocuronium.

The Differences in Bispectral Index according to Age during Sevoflurane Anesthesia in Children Aged 1-7 Years

Background: The bispectral index (BIS) was developed for adults, and the influence of neuronal and physiologic brain maturation on BIS in pediatric patients is unknown. The aim of this study was to evaluate BIS during anesthesia, using the same sevoflurane with respect to age in young children. Methods: Forty-two pediatric patients, aged 1-7 years, were enrolled in this study. Without premedication, anesthesia was induced with atropine, thiopental, and rocuronium and maintained with 2.0-2.5% sevoflurane and 50% -50% . After induction, a pediatric BIS sensor was applied and monitored throughout the maintenance of and emergence from anesthesia. Results: BIS was analyzed in different age groups; 1-2 yr (n = 14), 3-4 yr (n = 13), 5-7 yr (n = 15). Operation and anesthesia times were similar forthe three age groups. Mean BIS values from ten minutes after skin incision to just before sevoflurane cessation () were 67.0 6.2 for 1-2 yr, 50.5 9.4 for 3-4 yr, and 39.8 6.9 for 5-7 yr, and these values were significantly different for the three age groups. No significant differences were observed for extubation times, or times to a BIS value of 70 or 90 during anesthesia recovery. Conclusions: When monitoring BIS in children aged 1-7 yr during anesthesia with sevoflurane, the BIS trend rather than the absolute value is more important and the BIS data, especially in children under 3 years of age, should be interpreted cautiously.

The Effect of Ketorolac and Fentanyl on the Emergence Characteristics after Sevoflurane Anesthesia in Children Undergoing Tonsillectomy and Adenoidectomy

Background: The rapid emergence and recovery from general anesthesia provided by sevoflurane is associated with a frequent incidence of emergence agitation in children. In this study, we compared the emergence and recovery profiles of patients who received sevoflurane with or without intravenous ketorolac or/and fentanyl. Methods: By using a prospective, double blinded design, 60 children of 3 to 10 year of age, scheduled for elective tonsillectomy and adenoidectomy, were anesthetized with sevoflurane (1-3 vol%) in a 50% gas mixture. Patients were randomized to one of four groups (group 1: sevoflurane only, group 2: sevoflurane + ketorolac 0.5 mg/kg, group 3: sevoflurane + fentanyl 1, group 4: sevoflurane + ketorolac 0.5 mg/kg + fentanyl 1). A blinded observer evaluated each patient using an agitation scale, Faces scale and an Objective pain/discomfort scale. Results: No significant differences were observed among the four groups regarding age, sex, weight or duration of anesthesia. Recovery and discharge times were not statistically different. The incidence of severe agitation and the scores of Faces scale in the post anesthesia care unit, were significantly lower in groups 2, 3 and 4 than in group 1 (P of fentanyl or both were sufficient to prevent severe emergence agitation and pain in children undergoing tonsillectomy and adenoidectomy with sevoflurane anesthesia.

The Comparative Effects of Caudal Block and IV Ketorolac on Emergence Delirium after Sevoflurane Anesthesia in Children

Background: Children usually exhibit pain-related behavior in the postanesthetic care unit. The aim of the present study was to compare the recovery and emergence profiles of children who received sevoflurane with caudal block or IV ketolorac or none for inguinal herniorrhaphy. Methods: Forty five children, ASA 1, scheduled for herniorrhaphy were randomly assigned to receive either caudal block(n= 15), IV ketorolac (n = 15), or none (n = 15). All children were premedicated with midazolam(0.05 mg/kg) and glycopyrrolate (0.004 mg/kg) an hour before anesthesia induction. Thiopental sodium (5 mg/kg) and mask inhalation of sevoflurane 2 vol% in / 50/50 were used to induce anesthesia. After induction, group 1 received none, while groups 2 and 3 received a caudal block and IV ketorolac, respectively. Anesthesia was maintained by sevoflurane with N2O/O2 inhalation via an endotracheal tube. Recovery was assessed by an independent observer using a postansthetic recovery score. Pain score was also assessed by an independent observer using a pain/discomfort scale. Recovery and agitation characteristics on emergence were compared between the three groups. Results: There were no difference between the groups with respect to age, weight, duration of inhalation exposure, or recovery score. Agitation and pain scores were less in both the caudal block and IV ketorolac groups (P

Effect of nitrous oxide on cerebrovascular reactivity to carbon dioxide in children during sevoflurane anaesthesia

Sevoflurane and nitrous oxide have intrinsic cerebral vasodilatory activity. To determine the effects of nitrous oxide on cerebrovascular reactivity to carbon dioxide (CCO(2)R) during sevoflurane anaesthesia in children, middle cerebral artery blood flow velocity (V(mca)) was measured over a range of end-tidal carbon dioxide concentrations (E'(CO(2))), using transcranial Doppler (TCD) ultrasonography. Ten children aged 1.5-6 yr were anaesthetized with sevoflurane and received a caudal block. Patients were allocated randomly to receive either air-nitrous oxide or nitrous oxide-air. Further randomization determined the sequence of E'(CO(2)) (25, 35, 45, and 55 mm Hg) and sevoflurane (1.0 then 1.5 MAC or 1.5 then 1.0 MAC) concentrations. Once steady state had been reached, three measurements of V(mca), mean arterial pressure (MAP), and heart rate (HR) were recorded. Cerebrovascular carbon dioxide reactivity was reduced in the 25-35 mm Hg E'(CO(2)) range on the addition of nitrous oxide to 1.5 MAC, but not 1.0 MAC sevoflurane. A plateau in CCO(2)R of 0.4-0.6% per mm Hg was seen in all groups between E'(CO(2)) values of 45 and 55 mm Hg. Mean HR and MAP remained constant throughout the study period. Cerebrovascular carbon dioxide reactivity is reduced at and above an E'(CO(2)) of 45 mm Hg during 1.0 and 1.5 MAC sevoflurane anaesthesia. The addition of nitrous oxide to 1.5 MAC sevoflurane diminishes CCO(2)R in the hypocapnic range. This should be taken into consideration when hyperventilation techniques for reduction of brain bulk are being contemplated in children with raised intracranial pressure.

The use of remifentanil for intubation in paediatric patients during sevoflurane anaesthesia guided by Bispectral Index (BIS) monitoring

We studied the intubating conditions, haemodynamic and endocrine changes following tracheal intubation during sevoflurane anaesthesia guided by Bispectral Index (BIS) monitoring in 40 children who received either remifentanil 1 microg.kg-1 (group R) or saline 1 ml.kg-1 (group S). Acceptable intubating conditions were found in all patients in group R (n = 20), compared to only 12 patients in group S (p = 0.002). There were no intergroup differences in heart rate, systolic blood pressure and plasma concentrations of epinephrine and norepinephrine at any time point and changes in haemodynamic variables throughout the study period were moderate. Titration of sevoflurane delivery to a target BIS of 35 +/- 5 led to almost equal end-tidal sevoflurane concentrations in either group and remifentanil did not affect the BIS. There were no side-effects in either group that required intervention. Intubating conditions during sevoflurane anaesthesia in children were found to be improved by a single bolus dose of remifentanil 1 microg.kg-1.

Cerebral autoregulation in children during sevoflurane anaesthesia

Little is known about cerebral autoregulation in children. The aim of this study was to examine cerebral autoregulation in children. Cerebral autoregulation testing was performed during less than 1 MAC sevoflurane anaesthesia in children (from 6 months to 14 yr) and in adults (18-41 yr). Mean middle cerebral artery flow velocities (V(MCA)) were measured using transcranial Doppler ultrasonography. Mean arterial pressure (MAP) was increased to whichever was greater: 20% above baseline or (i) 80 mm Hg for less than 9 yr, (ii) 90 mm Hg for 9-14 yr, and (iii) 100 mm Hg for adults. Cerebral autoregulation was considered intact if the autoregulatory index was > or =0.4. There were 13 subjects less than 2 yr old (Group 1), 13 subjects 2-5 yr (Group II), 14 subjects 6-9 yr (Group III), 12 subjects 10-14 yr (Group IV), and 12 adults (Group V; control group). All subjects had an autoregulatory index > or =0.4. There was no difference in autoregulatory index between children in Groups I-IV or between children and adults. We found no age-related differences in autoregulatory capacity during low-dose sevoflurane anaesthesia. We report no differences in autoregulatory capacity between children and adults.

The Hypnotic and Analgesic Effects of Oral Clonidine During Sevoflurane Anesthesia in Children: A Dose–Response Study

The Hypnotic and Analgesic Effects of Oral Clonidine During Sevoflurane Anesthesia in Children: A Dose–Response Study

The Effect of Fentanyl on the Emergence Characteristics After Desflurane or Sevoflurane Anesthesia in Children

The Effect of Fentanyl on the Emergence Characteristics After Desflurane or Sevoflurane Anesthesia in Children

Sevoflurane anaesthesia in children after induction of anaesthesia with midazolam and thiopental does not cause epileptiform EEG

Sevoflurane is a methyl ether anaesthetic commonly used for induction and maintenance of general anaesthesia in children. Sevoflurane is a non-irritant and acts quickly so induction is usually calm. However, inhalation induction with high concentrations of sevoflurane can cause convulsion-like movements and seizure-like changes in the electroencephalogram (EEG). Little is known about the EEG during maintenance of anaesthesia with sevoflurane, so we planned a prospective trial of sevoflurane maintenance after i.v. induction with benzodiazepine and barbiturate, which is another common induction technique in children. EEG recordings were made before premedication with midazolam (0.1 mg kg(-1) i.v.), during induction of anaesthesia with thiopental (5 mg kg(-1)), and during maintenance with sevoflurane (2% end-tidal concentration in air/oxygen without nitrous oxide) in 30 generally healthy, 3- to 8-year-old children having adenoids removed. Noise-free EEG data of good quality were successfully recorded from all 30 children. Two independent neurophysiologists did not detect epileptiform discharges in any of the recordings. Premedication with midazolam, i.v. induction with thiopental and maintenance of anaesthesia with 2% sevoflurane in air does not cause epileptiform EEG patterns in children.

The Hypnotic and Analgesic Effects of Oral Clonidine During Sevoflurane Anesthesia in Children: A Dose-Response Study

The Hypnotic and Analgesic Effects of Oral Clonidine During Sevoflurane Anesthesia in Children: A Dose-Response Study

The Effect of Intranasal Fentanyl on the Emergence Characteristics After Sevoflurane Anesthesia in Children Undergoing Surgery for Bilateral Myringotomy Tube Placement

The Effect of Intranasal Fentanyl on the Emergence Characteristics After Sevoflurane Anesthesia in Children Undergoing Surgery for Bilateral Myringotomy Tube Placement

Probability of acceptable intubation conditions with low dose rocuronium during light sevoflurane anaesthesia in children

To define the rocuronium doses which would provide 50%, 90%, and 95% probability of 'acceptable' intubation conditions during light sevoflurane anaesthesia, we studied 60 children aged 2-7 years in a prospective, randomised, assessor blinded study. After mask ventilation with 1 MAC sevoflurane/N2O for 17+/-1 (x+/-SD) min we administered rocuronium (either 0.15, 0.22, 0.3, 0.5, or 1.0 mg. kg(-1)) or placebo, and quantified the evoked force of the adductor pollicis muscle. Intubation conditions were assessed before and 2 min after injection of the test drug. Intubation conditions were improved significantly with rocuronium and scored 'acceptable' in 70%, 90%, and 100% of the children after injection of rocuronium 0.15, 0.22, and 0.3 mg x kg(-1), respectively. In parallel, twitch tension decreased to 53% (6-100), 26% (11-100), and 11% (0-19) of baseline (median (range)). Recovery of train-of-four ratio to 0.8 was achieved 13 (7-19), 16 (8-28), and 27 (23-44) min after injection of the respective rocuronium doses. Higher rocuronium doses did not further improve intubation conditions but only prolonged time of neuromuscular recovery. Logistic regression analysis revealed that rocuronium 0.11 (CI 0.05-0.16), 0.21 (0.14-0.28), and 0.25 (0.15-0.34) mg x kg(-1) provides a 50%, 90%, and 95% probability of 'acceptable' intubation conditions in children during 1 MAC sevoflurane/N2O anaesthesia, respectively. Furthermore, we calculated that force depression of adductor pollicis muscle to 81% (CI 72-90), 58% (42-74), and 50% (29-71) of baseline is associated with 50%, 90%, and 95% probability of 'acceptable' intubation conditions. Submaximal depression of muscle force with low dose rocuronium improves intubation conditions in children during light sevoflurane anaesthesia while allowing rapid recovery of neuromuscular function. However, when using low dose rocuronium neuromuscular monitoring may be helpful to detect children with inadequate response to the relaxant so as to avoid an unsuccessful intubation attempt.

Excitation phenomena during sevoflurane anaesthesia in children

The advantages of rapid induction of and emergence from sevoflurane anaesthesia may be more than offset by the frequent occurrence of agitation during induction and recovery, and a possible epileptogenic effect. The mechanisms and possible strategies to prevent these drawbacks are reviewed, on the basis of the most recent literature.

Fentanyl augments block of sympathetic responses to skin incision during sevoflurane anaesthesia in children

We studied 61 healthy ASA 1 patients (aged 2-6 yr) to determine if fentanyl affects the minimum alveolar concentration which blocks adrenergic responses to skin incision (MAC-BAR) in 50% of children in the presence of 60% nitrous oxide. Patients were allocated randomly to one of three fentanyl groups to receive 0, 2 or 4 micrograms kg-1. Patients also received sevoflurane at a preselected end-tidal concentration according to an 'up-and-down' design. After a steady-state sevoflurane concentration had been maintained for at least 15 min, fentanyl was given i.v. Skin incision was performed 5 min after administration of fentanyl. The response was considered positive if heart rate (HR) or mean arterial pressure (MAP) increased by 15% or more. The MAC-BAR of sevoflurane was 1.45 MAC (95% confidence intervals 1.25-1.65 MAC), and this was reduced markedly to 0.63 MAC and 0.38 MAC by addition of fentanyl 2 and 4 micrograms kg-1, respectively. A ceiling effect was not observed and there was a significant difference between the 2 and 4 micrograms kg-1 groups.

Respiratory Mechanics During Sevoflurane Anesthesia in Children With and Without Asthma

Respiratory Mechanics During Sevoflurane Anesthesia in Children With and Without Asthma

Respiratory Mechanics During Sevoflurane Anesthesia in Children With and Without Asthma

We studied lung function in children with and without asthma receiving anesthesia with sevoflurane. Fifty-two children had anesthesia induced with sevoflurane (up to 8%) in a mixture of 50% nitrous oxide in oxygen and then maintained at 3% with children breathing spontaneously via face mask and Jackson-Rees modification of the T-piece. Airway opening pressure and flow were then measured. After insertion of an oral endotracheal tube under 5% sevoflurane, measurements were repeated at 3%, as well as after increasing to 4.2%. Respiratory system resistance (Rrs) and compliance during expiration were calculated using multilinear regression analysis of airway opening pressure and flow, assuming a single-compartment model. Data from 44 children were analyzed (22 asthmatics and 22 normal children). The two groups were comparable with respect to age, weight, ventilation variables, and baseline respiratory mechanics. Intubation was associated with a significant increase in Rrs in asthmatics (17% +/- 49%), whereas in normal children, Rrs slightly decreased (-4% +/- 39%). At 4.2%, Rrs decreased slightly in both groups with almost no change in compliance system resistance. We concluded that in children with mild to moderate asthma, endotracheal intubation during sevoflurane anesthesia was associated with increase in Rrs that was not seen in nonasthmatic children. Tracheal intubation using sevoflurane as sole anesthetic is possible and its frequency is increasing. When comparing children with and without asthma, tracheal intubation under sevoflurane was associated with an increase in respiratory system resistance in asthmatic children. However, no apparent clinical adverse event was observed.

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 [micro sign]g/kg IV before the induction of anesthesia with sevoflurane up to 8 vol% inspired concentration in N2 O 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. (Anesth Analg 1999;89:75-9)

Decreased Mivacurium Requirements and Delayed Neuromuscular Recovery During Sevoflurane Anesthesia in Children and Adults

The purpose of this study was to compare the mivacurium infusion requirements and neuromuscular recovery in adults and children during propofol/opioid and sevoflurane anesthesia.Seventy-five adult and 75 pediatric patients were randomized to receive propofol/opioid 0.5 or 1.0 minimum alveolar anesthetic concentration (MAC) (age-related) sevoflurane anesthesia. Plasma cholinesterase (PChE) activity was measured. Neuromuscular blockade was monitored by train-of-four (TOF) stimulation every 10 s and adductor pollicis electromyography. A bolus of 2 x the 95% effective dose of mivacurium (0.25 mg/kg) was followed by an infusion titrated to maintain 90%-95% blockade. Mivacurium doses were recorded every 5 min. At the end of surgery, the infusion was stopped, and recovery from mivacurium was monitored until TOF >or=to0.7. PChE concentrations were within the normal range (adults 4-12 KU/L, children 6-16 KU/L) and correlated with mivacurium dose. Mivacurium infusion rates were higher in children than in adults: at 30 min, the rates in children were 13.1 +/- 6.4, 8.1 +/- 4.7, and 5.2 +/- 2.9 [micro sign]g [center dot] kg-1 [center dot] min-1 at 0, 0.5, and 1.0 MAC sevoflurane, respectively; the corresponding rates in adults were 5.9 +/- 3.1, 4.3 +/- 1.7, and 2.9 +/- 0.7 [micro sign]g [center dot] kg-1. min-1 (P < 0.01). Sevoflurane decreased mivacurium requirements, maximal decreases at 45 min in children and 10 min in adults, and delayed neuromuscular function recovery. Children recovered twice as quickly as adults, achieving TOF >or=to 0.7 at 9.8 +/- 2.5, 11.4 +/- 2.8, and 19.6 +/- 6.3 min compared with 19.9 +/- 5.4, 26.4 +/- 8.3, and 32.9 +/- 9.8 min in adults (P < 0.0001). In conclusion, mivacurium requirements were correlated with PChE, were greater in children than in adults, and were reduced by sevoflurane. Neuromuscular recovery occurred more rapidly in children and was delayed by sevoflurane. Implications: The mivacurium infusion requirement to maintain constant 90%-95% neuromuscular block during anesthesia is correlated with plasma cholinesterase activity. It is increased in children and reduced by the inhaled anesthetic sevoflurane. Despite the larger dose administered to children, recovery from block occurred more rapidly in children than in adults and was delayed by sevoflurane. (Anesth Analg 1998;87:772-8)

Heart rate and blood pressure variability during halothane or sevoflurane anesthesia in children

Heart rate and blood pressure variability during halothane or sevoflurane anesthesia in children