Sevoflurane sedation in infants undergoing MRI: a preliminary report

Does sevoflurane sedation in pediatric patients lead to "pseudo" leptomeningeal enhancement in the brain on 3 Tesla magnetic resonance imaging?

BACKGROUND

Prominent leptomeningeal contrast enhancement (LMCE) in the brain is observed in some pediatric patients during sedation for imaging. However, based on clinical history and cerebrospinal fluid analysis, the patients are not acutely ill and do not exhibit meningeal signs. Our study determined whether sevoflurane inhalation in pediatric patients led to this pattern of 'pseudo' LMCE (pLMCE) on 3 Tesla magnetic resonance imaging (MRI).

AIM

To highlight the significance of pLMCE in pediatric patients undergoing enhanced brain MRI under sedation to avoid misinterpretation in reports.

METHODS

A retrospective cross-sectional evaluation of pediatric patients between 0-8 years of age was conducted. The patients underwent enhanced brain MRI under inhaled sevoflurane. The LMCE grade was determined by two radiologists, and interobserver variability of the grade was calculated using Cohen's kappa. The LMCE grade was correlated with duration of sedation, age and weight using the Spearman rho rank correlation.

RESULTS

A total of 63 patients were included. Fourteen (22.2%) cases showed mild LMCE, 48 (76.1%) cases showed moderate LMCE, and 1 case (1.6%) showed severe LMCE. We found substantial agreement between the two radiologists in detection of pLMCE on post-contrast T1 imaging (kappa value = 0.61; P < 0.001). Additionally, we found statistically significant inverse and moderate correlations between patient weight and age. There was no correlation between duration of sedation and pLMCE.

CONCLUSION

pLMCE is relatively common on post-contrast spin echo T1-weighted MRI of pediatric patients sedated by sevoflurane due to their fragile and immature vasculature. It should not be misinterpreted for meningeal pathology. Knowing pertinent clinical history of the child is an essential prerequisite to avoid radiological overcalling and the subsequent burden of additional investigations.

Needle-free pharmacological sedation techniques in paediatric patients for imaging procedures: a systematic review and meta-analysis

BACKGROUND

Sedation techniques and drugs are increasingly used in children undergoing imaging procedures. In this systematic review and meta-analysis, we present an overview of literature concerning sedation of children aged 0-8 yr for magnetic resonance imaging (MRI) procedures using needle-free pharmacological techniques.

METHODS

Embase, MEDLINE, Web of Science, and Cochrane databases were systematically searched for studies on the use of needle-free pharmacological sedation techniques for MRI procedures in children aged 0-8 yr. Studies using i.v. or i.m. medication or advanced airway devices were excluded. We performed a meta-analysis on sedation success rate. Secondary outcomes were onset time, duration, recovery, and adverse events.

RESULTS

Sixty-seven studies were included, with 22 380 participants. The pooled success rate for oral chloral hydrate was 94% (95% confidence interval [CI]: 0.91-0.96); for oral chloral hydrate and intranasal dexmedetomidine 95% (95% CI: 0.92-0.97); for rectal, oral, or intranasal midazolam 36% (95% CI: 0.14-0.65); for oral pentobarbital 99% (95% CI: 0.90-1.00); for rectal thiopental 92% (95% CI: 0.85-0.96); for oral melatonin 75% (95% CI: 0.54-0.89); for intranasal dexmedetomidine 62% (95% CI: 0.38-0.82); for intranasal dexmedetomidine and midazolam 94% (95% CI: 0.78-0.99); and for inhaled sevoflurane 98% (95% CI: 0.97-0.99).

CONCLUSIONS

We found a large variation in medication, dosage, and route of administration for needle-free sedation. Success rates for sedation techniques varied between 36% and 98%.

Long Term Neurodevelopmental Outcomes after Sevoflurane Neonatal Exposure of Extremely Preterm Children: A Cross-Sectional Observationnal Study

Sevoflurane, a volatile anesthetic, is used when extremely preterm neonates (EPT) undergo painful procedures. Currently, no existing studies analyze sevoflurane’s long-term effects during the EPT’s immediate neonatal period. Our primary objective was to compare the EPT’s neurocognitive development regardless of any sevoflurane exposure prior to 45 weeks corrected gestational age (GA). We analyzed those live discharges, less than 28 weeks GA, who were either exposed, unexposed, and/or multiply exposed to sevoflurane before 45 weeks GA. All data were obtained from a cross-sectional multicenter study (GPQoL study, NCT01675726). Children, both exposed and non-exposed to sevoflurane, were sampled using a propensity-guided approach. Neurological examinations (Touwen), cognitive and executive functions (WISC IV, NEPSY, Rey figure), and assessments when the children were between 7 and 10 years old, were correlated to their neonatal sevoflurane exposure. There were 139 children in the study. The mean gestational age was 26.2 weeks (±0.8) GA and the mean birth weight was 898 g (±173). The mean age of their evaluation was 8.47 years old (±0.70). Exposure to sevoflurane to the mean corrected age 27.10 (3.37) weeks GA had a significant correlation with cerebral palsy (adjusted odds ratio (aOR): 6.70 (CI 95%: 1.84–32.11)) and other major disorders (cerebral palsy and/or severe cognitive retardation) (aOR: 2.81 [95% CI: 1.13–7.35]). Our results demonstrate the possibility of long-term effects on EPT infants who had a sevoflurane exposure before 45 weeks corrected GA. However, these results will require further confirmation by randomized controlled trials.

Drug selection for sedation and general anesthesia in children undergoing ambulatory magnetic resonance imaging

The demand for drug-induced sedation for magnetic resonance imaging (MRI) scans have substantially increased in response to increases in MRI utilization and growing interest in anxiety in children. Understanding the pharmacologic options for deep sedation and general anesthesia in an MRI environment is essential to achieve immobility for the successful completion of the procedure and ensure rapid and safe discharge of children undergoing ambulatory MRI. For painless diagnostic MRI, a single sedative/anesthetic agent without analgesia is safer than a combination of multiple sedatives. The traditional drugs, such as chloral hydrate, pentobarbital, midazolam, and ketamine, are still used due to the ease of administration despite low sedation success rate, prolonged recovery, and significant adverse events. Currently, dexmedetomidine, with respiratory drive preservation, and propofol, with high effectiveness and rapid recovery, are preferred for children undergoing ambulatory MRI. General anesthesia using propofol or sevoflurane can also provide predictable rapid time to readiness and scan times in infant or children with comorbidities. The selection of appropriate drugs as well as sufficient monitoring equipment are vital for effective and safe sedation and anesthesia for ambulatory pediatric MRI.

Ten-year experience with standardized non-operating room anesthesia with Sevoflurane for MRI in children affected by neuropsychiatric disorders

Background

Children require anesthesia for MRI to maintain immobility and reduce discomfort; clear indications about the best anesthesiologic management are lacking and each center developed its own protocol. Moreover, children with neuropsychiatric disorders more likely require sedation and are described in literature as more prone to general and respiratory complications. Aim of this study was to analyze the applicability of a sevoflurane-based approach, to describe general and respiratory complications and to identify risk factors in a pediatric neuropsychiatric population.

Methods

Retrospective cohort study, university Hospital (January 2007–December 2016). All the 1469 anesthesiologic records of children addressed from Neuropsychiatric Unit to undergo MRI under general anesthesia were analyzed; 12 patients equal or older than 18-year-old were excluded. We identified post-hoc nine macro-categories: static encephalopathies, metabolic/evolutive encephalopathies, epileptic encephalopathies, neuromuscular diseases, autistic spectrum disorders, migraine, psychiatric disorders, intellectual disabilities, others. A logistic regression model for events with low frequency (Firth’s penalized likelihood approach) was carried out to identify the mutually adjusted effect among endpoints (complications) and the independent variables chosen on the basis of statistical significance (univariate analysis, p ≤ 0.05) and clinical judgment.

Results

Of 1457 anesthesiologic records (age 4.0 (IQR 2.0 to 7.0) year-old, males 891 (61.2%), weight 17.0 (IQR 12.0 to 24.9) kg), 18 were cancelled for high anesthesiologic risk, 50 were cooperative, 1389 were anesthetized. A sevoflurane-based anesthesia was feasible in 92.3%; these patients required significantly less mechanical ventilation (8.6 vs. 16.2%; p = 0.012). Complications’ rate was low (6.2%; 3.1% respiratory). The risk for general complications increases with ASA score > 1 (OR 2.22, 95 CI% 1.30 to 3.77, p = 0.003), male sex (OR 1.73, 95% CI 1.07 to 2.81, p = 0.025), multi-drug anesthesia (OR 2.98, 95 CI% 1.26 to 7.06, p = 0.013). For respiratory complications, it increases with ASA score > 1 (OR 2.34, 95 CI% 1.19 to 4.73, p = 0.017), autumn-winter (OR 2.01, 95 CI% 1.06 to 3.78, p = 0.030), neuromuscular disorders (OR 3.18, 95 CI% 1.20 to 8.41, p = 0.020). We had no major complications compromising patients’ outcome or requiring admission to ICU.

Conclusions

Sevoflurane anesthesia is feasible and safe for children affected by neuropsychiatric disorders undergoing MRI. Specific risk factors for general and respiratory complications should be considered.

Serious airway-related adverse events with sevoflurane anesthesia via facemask for magnetic resonance imaging in 7129 pediatric patients: A retrospective study

OBJECTIVE

This retrospective study evaluated the safety and effectiveness of sevoflurane anesthesia by facemask for magnetic resonance imaging (MRI) scanning among pediatric patients in a high-volume MRI department.

METHODS

The medical records of 7129 pediatric patients (median age 12 months, range 4.0-36.0 months) who were administered anesthesia during MRI scanning were reviewed. Anesthesia via 8% and 1.5%-2% sevoflurane was used for induction and maintenance, respectively. All the patients were monitored by anesthetists in the postanesthesia care unit. Vital signs were recorded every 5 minutes. Airway-related adverse events, sevoflurane induction time, MRI scanning time, and recovery time were recorded. Patients were discharged when no complications were found for 10-15 minutes, with Aldrete's score ≥9.

RESULTS

After sevoflurane anesthesia, there were 28 severe airway-related adverse events (0.4%, 95% CI: 0.2%-0.5%), and 12 patients had severe respiratory apnea (0.2%, 95% CI: 0.1%-0.2%). The percentage of patients with respiratory apnea was significantly higher in preterm infants compared with term infants (2.4% cf. 0.5%, P = 0.012). Sixteen patients had severe airway obstruction (0.2%, 95% CI: 0.1%-0.3%).

CONCLUSION

The major severe airway-related adverse events among pediatric patients associated with sevoflurane anesthesia were respiratory apnea and airway obstruction. The respiratory condition of preterm infants should be monitored carefully when under sevoflurane anesthesia. Overall, sevoflurane is safe and can be used efficiently for pediatric anesthesia in high-volume MRI departments.

Safe pediatric procedural sedation and analgesia by anesthesiologists for elective procedures: A clinical practice statement from the European Society for Paediatric Anaesthesiology

The growing number of medical procedures performed in children that require cooperation of patients, lack of movement, anxiolysis or/and analgesia triggers the increased need for procedural sedation. This document presents the consensus statement of the European Society for Paediatric Anaesthesiology about the principles connected with the safe management of procedural sedation and analgesia (PSA) by anaesthesiologists for elective procedures in children. It does not aim to provide a legal statement on how and by whom PSA should be performed. The document highlights that any staff taking part in sedation of children must be appropriately trained with the required competencies and must be able to demonstrate regularly that they have maintained their knowledge, skills and clinical experience. The main goal of creating this document was to reflect the opinions of the community of the paediatric anaesthesiologists in Europe regarding how PSA for paediatric patients should be organized to make it safe.

Using nasal cannula for sevoflurane deep sedation in emergency dental treatment

Background

Emergency room doctors run into difficulties in treating injured pediatric patients because usually they fell into panic after trauma. In these situation, deep sedation with sevoflurane is fully recommendable method. The conventional way can interrupt common dental treatment procedure.

Methods

In the present study, nasal cannula was used for sevoflurane deep sedation in 11 dental emergency treatment. Age ranged from 0 to 3 years old (average of 1.8 years).

Results

Treatment duration was from 10 to 35 minutes (average of 16.7 minutes). Average duration of sedation was 25.5 minutes ranging from 15 to 45 minutes.

Conclusions

It has advantages to use nasal cannula for sevoflurane deep sedation rather than conventional intubation; saves time and secures good operation field.

Deep sedation with sevoflurane insufflated via a nasal cannula in uncooperative child undergoing the repair of dental injury

Sevoflurane, a potent volatile anesthetic, has been attempted to be used for procedural sedation. Because of lack of a commercially available sedation apparatus for sevoflurane administration, anesthetic gas delivery apparatus should be connected to general anesthetic machine for delivering sevoflurane gas. In this case, deep sedation was maintained during treatment of dental injuries involving the upper lip and incisor by sevoflurane insufflations via a nasal cannula. Especially, this may be advantageous in treating dental injuries involving upper lip and maxillary anterior teeth because the treatment is not disturbed during sevoflurane insufflations via a nasal cannula.

Defining awakening from anesthesia in infants: a narrative review of published descriptions and scales of behavior

OBJECTIVES

A descriptive tool or validated scale of consciousness is desirable in infants to test the value of any depth of anesthesia monitor.

METHODS

We have reviewed published descriptions and scales of observed behavior that may be applicable to the study of infants during the transition from anesthesia to wakefulness.

RESULTS

Potentially useful scales were found that had been developed for the assessment and study of natural sleep, neurological state, arousal, anesthesia, sedation, coma, and pain. Scales or criteria of behavior had been developed for anesthetised children, but there were no agreed definitions or criteria specifically for anesthetised infants or neonates.

CONCLUSION

Criteria for awakening of infants from anesthesia need to be developed and agreed.

Comparison of effective inspired concentration of sevoflurane in preterm infants with different postconceptual ages

OBJECTIVE

Screening examination for retinopathy of prematurity (ROP) is stressful and painful to the neonate. Sevoflurane has been used successfully in anesthesia for full-term and premature neonates and has been recently used for pediatric outpatient procedures. In this study, we examined the effective inspired concentration of sevoflurane to prevent movement in response to stimulation of examination in 50% of patients (EIC50) of sevoflurane, as well as the response of sevoflurane to age in the preterm outpatients undergoing fundus examination.

METHODS

Preterm pediatric outpatients at different postconceptual ages (duration from the mother's last menstrual period to the date when the examination for ROP was performed) with <44 weeks (group A) and 44-64 weeks (group B) undergoing fundus examination were included. SpO(2) and ECG were monitored in operation room. In the process of anesthetic induction, the oxygen flow rates were 3 l·min(-1), and subjects spontaneously breathed 6% sevoflurane by mask. The time to loss of movement was recorded as induction time. Six percent sevoflurane was inhaled continuously for the same duration, and then the inspired concentration of sevoflurane was adjusted to maintenance concentration. When no movement or crying was observed, the speculums were used to keep the eyelids open, and then the eye examinations were performed by the same ophthalmologist. During induction time and maintenance time, the occurrence of coughing, clenching, gross purposeful movement, breath holding or desaturation to SpO(2) < 95% was recorded. After completion of the procedure, patients were observed in the same room until spontaneous eye opening or verbalization occurred. Up and down method was used to determine subsequent maintenance concentration in each group. The initial maintenance concentration was 3%. The gradient of increase or decrease was 0.5%. If the preceding subject had not moved, the sevoflurane concentration was decreased by 0.5%; if the preceding subject had moved, the concentration was increased by 0.5%. When at least six independent alternations from no-movement to movement were observed, test was terminated.

RESULTS

Twenty-four pediatric outpatients completed the investigation in group A. The effective inspired concentration prevented movement in response to stimulation of examination in 50% of patients (EIC50) of sevoflurane was 2.5% in group A. Twenty-seven patients completed the investigation and EIC50 values of sevoflurane were 3.0% in group B. The induction time in group A was significantly lower than that in group B. The gestational ages, anesthesia time, and awake time were similar in two groups.

CONCLUSION

Anesthesia with inhaled sevoflurane by a face mask can be accomplished in preterm outpatients undergoing fundus examination without intubation and i.v. accession. The EIC50 is lower, and the induction time is shorter in smaller aged patients compared with those in older ones.

Efficacy of different concentrations of sevoflurane administered through a face mask for magnetic resonance imaging in children

BACKGROUND

The main aim of this study was to use a non-invasive method such as a face mask to maintain anesthesia in children during magnetic resonance imaging (MRI). The secondary aim was to ascertain hemodynamic-respiration parameters, recovery time and complications of anesthesia with the administration of different concentrations of sevoflurane.

METHODS

This prospective and randomized study included 96 ASA I-II children, aged 1-10, scheduled to undergo MRI with anesthesia with sevoflurane through a face mask. All patients were administered midazolam 0.5 mg·kg(-1) orally 30 min before anesthesia induction. Sevoflurane 8% was given to induce anesthesia under assisted-controlled ventilation for 2 min, and an intravenous route was opened on the hand. Three different concentrations of sevoflurane were administered through a face mask under spontaneous respiration to maintain anesthesia. A mixture of sevoflurane, oxygen, and air of 5 l·min(-1) was given through a face mask for anesthesia. Group 1 (n = 32) received 1.5% sevoflurane, Group 2 (n = 32) 1.25% sevoflurane, and Group 3 (n = 32) 1.0% sevoflurane. Recovery time, removal from the MRI room, postanesthesia care unit discharge data, and complications were also recorded. Heart rate, mean arterial pressure (MAP), peripheral oxygen saturation (SpO(2)), respiration rate, and anesthesia adequacy were recorded every 5 min from the time of induction until completion of the MRI.

RESULTS

All three groups were similar in demographic and hemodynamic respiratory features. MRI was successfully performed in 96.6% of all patients without additional intervention. Sevoflurane concentrations were increased for a short time in one patient in Group 1 and in two patients in Group 3. Oxygen flow was increased in one patient in Group 1 and in one patient in Group 2 as SpO(2) was lower than 95%. The mean time to eye opening (from discontinuation of sevoflurane to eye opening) was 155.8 ± 50.0 s in Group 1, 89.5 ± 16.0 s in Group 2, and 53.5 ± 10.0 s in Group 3; differences between the groups were statistically significant (P = 0.001). Airways were not used on any of the patients, and none vomited or required endotracheal intubation or laryngeal mask anesthesia.

CONCLUSIONS

We believe that the administration of sevoflurane at a concentration of 1% via a face mask under spontaneous respiration may provide light anesthesia without complications to induce an unarousable sleep for children during MRI.

Variations in velopharyngeal structures between upright and supine positions using upright magnetic resonance imaging

OBJECTIVE

No studies have used MRI to compare the dimensional changes of the velopharyngeal musculature between upright and supine positions. The purpose of this study is to provide a comparison between structures of the velopharyngeal mechanism while in the supine and upright positions during rest and sustained speech productions of four female subjects.

METHODS

Four healthy white female subjects between 30 and 36 years of age (mean, 32.5 ± 1.75 years) were imaged using a 0.6-tesla open-type multi-position MRI scanner. Subjects produced two speech tasks (/i/ and /s/) in the two body positions.

RESULTS

Velar measures (length, thickness, and height), pharyngeal measures (retrovelar and retrolingual), and levator muscle measures (length and angles of origin) demonstrated a small variation between upright and supine positions. Differences in velar height during production of /i/ between the two positions was significant for all subjects. In most cases, the velar thickness remained nearly the same (group mean difference was between -0.2 and 1.2 mm). Group means demonstrated an average levator muscle shortening from upright to supine of 2.8 mm at rest, 2.0 mm during /i/ production, and 2.3 mm during /s/ production. Percentage of levator shortening were 17% for /i/ production and 21% for /s/ production, which were independent of body position.

CONCLUSIONS

Overall, gravity had a minimal effect on velar thickness, velar length, velar height, levator muscle length, angles of origin, and pharyngeal dimensions. Differences between the two body positions (upright and supine) were not significant during rest or during production of /i/ and /s/, with the exception of velar height during /i/ production.

Sevoflurane inside and outside the operating room

BACKGROUND

Sevoflurane is often presented as a near-perfect anaesthetic. After 10 years in the operating room, new uses are emerging outside.

OBJECTIVE

To remind readers of the principal characteristics of sevoflurane, to affirm its usefulness for day-case anaesthesia and to consider the recent new uses.

METHODS

The discussion of the physical properties, pharmacokinetics, metabolism, mechanisms of action and clinical effects is based on classic, essential papers. Recent literature concerning emerging utilizations of sevoflurane was analysed.

RESULTS

Sevoflurane presents many benefits with minimum inconvenience. It allows rapid inhalation induction, maintenance and rapid recovery. It has little toxicity and its haemodynamic and respiratory depressive effects are moderate and well tolerated. It is already widely use for sedation for magnetic resonance imaging in children. Its use in paediatric or adult intensive care could improve the management of pain and sedation.

Therapeutic applications and uses of inhalational anesthesia in the pediatric intensive care unit

OBJECTIVE

To review the physical properties, end-organ effects, therapeutic applications, and delivery techniques of inhalational anesthetic agents in the pediatric intensive care unit.

DATA SOURCE

A computerized, bibliographic search regarding intensive care unit applications of inhalational anesthetic agents.

MAIN RESULTS

Although the end-organ effects of inhalational anesthetic agents vary depending on the agent, general effects include a dose-related depression of ventilatory and cardiovascular function. With increasing anesthetic depth, there is a decrease in alveolar ventilation with a reduction in tidal volume and an increase in PaCO2 in spontaneously breathing patients. The potent inhalational anesthetic agents decrease mean arterial pressure and myocardial contractility. The decrease in mean arterial pressure reduces renal and hepatic blood flow. Secondary effects on end-organ function may result from the metabolism of these agents and the release of inorganic fluoride. Beneficial effects include sedation, amnesia, and anxiolysis, making these agents effective for sedation during mechanical ventilation. Bronchodilatory and anticonvulsant properties have led to their use as therapeutic agents in patients with refractory status asthmaticus and epilepticus. Issues regarding their delivery in the intensive care unit include equipment for their delivery, scavenging, and monitoring.

CONCLUSIONS

The literature contains reports of the therapeutic use of the potent inhalational anesthetic agents in the pediatric intensive care unit. Potential applications include sedation during mechanical ventilation as well as therapeutic use for the treatment of status asthmaticus and epilepticus.

Evaluation of propofol for repeated prolonged deep sedation in children undergoing proton radiation therapy

BACKGROUND

The aim of this study is to evaluate the safety and sufficiency of a fixed dose rate propofol infusion for repeated prolonged deep sedation in children for proton radiation therapy (PRT).

METHODS

With ERB approval, we recorded anaesthesia monitoring data in children undergoing repeated prolonged propofol sedation for PRT. Sedation was introduced with a single bolus of i.v. midazolam 0.1 mg kg(-1) followed by repeated small boluses of propofol until sufficient depth of sedation was obtained. Sedation was maintained with fixed dose rate propofol infusion of 10 mg kg(-1) h(-1) in all patients up to the end of the radiation procedure. Patient characteristics, number and duration of sedation, propofol induction dose, necessity to alter propofol infusion rate, and heart rate, mean arterial pressure, respiratory rate were noted at the end of the radiation procedure before cessation of the propofol infusion. Data are mean (sd) or range (median) as appropriate.

RESULTS

Eighteen children aged from 1.4 to 4.2 yr (2.6 yr) had 27.6 (sd 2.0) (497 in total) radiation procedures within 44.1 (4.0) days lasting 55.7 (8.8) min. Propofol bolus dose for induction, monitoring, and positioning was 3.7 (1.0) mg kg(-1). Propofol bolus requirements were quite stable over the successive weeks of treatment and variability was larger between individuals than over time. In none of the children did propofol infusion rate need to be changed from the pre-set 10 mg kg(-1) h(-1) flow rate because of haemodynamic state, respiratory conditions or inadequate anaesthesia.

CONCLUSIONS

Repeated prolonged deep sedation over several weeks in very young children using a fixed rate propofol infusion was safe and adequate for all patients.

Quelle anesthésie pour les IRM en pédiatrie? Résultats d'une enquête par Internet dans les CHU de France

OBJECTIVE

To investigate the procedures used by French anaesthesiologists in children undergoing MRI.

METHODS

A questionnaire was sent by Internet to every university hospital in France. Information concerning the specialty of the doctor in charge of the child, the age of the children, premedication, airway control, the agents used, presence of a specific recovery room, length of hospitalization and number of children undergoing MRI was obtained.

RESULTS

Out of the 28 hospitals contacted, one did not reply and two did not perform anaesthesia for MRI. In 80% of cases, paediatric anaesthesiologists were in charge of the children. Only one team applied an age limit and performed sedation only in children over 10 kg. Specific monitoring for MRI was used by all teams. Premedication was given in 52% of cases. Parents were present during induction in 52% of cases. Sevoflurane was used in 52%, propofol in 40% and propofol with sufentanil in 8%. Presence of a venous line is systematic in 92% of cases. Intubation is systematic in 36% of cases, laryngeal mask in 20%, one or the other in 24%, and face mask and/or oral canula in 20%. The most widely used ventilation mode is spontaneous breathing (52%). All children go to the recovery room, which was close to the MRI unit in only 48% of cases and was less than 1 hour away in 72%. In 83% of cases, MRI is performed on a day-case basis and the number of procedures varies from 4 to 30 per week.

CONCLUSION

While there is no standard anaesthetic protocol in France for children undergoing MRI, only specialist teams undertake such procedures.

Anesthesia management for the child with Sanjad-Sakati syndrome

Sanjad-Sakati syndrome (SSS) is a rare genetic disorder characterized by congenital hypoparathyroidism, hypocalcemia and hyperphosphatemia, seizures, severe intrauterine and postnatal growth failure, dwarfism, mental retardation, dysmorphic features including retromicrognathia and abnormal dentition and increased susceptibility to infection. It is mainly confined to children in the Middle-East countries. We report the anesthesia management of a 12-year-old boy with SSS for dental treatment, and discuss the anesthesia implications of this disorder.

Dexmedetomidine decreases emergence agitation in pediatric patients after sevoflurane anesthesia without surgery

BACKGROUND

The purpose of the present study was to determine whether prophylactic use of 1 microg x kg(-1) dexmedetomidine affected the incidence of emergence agitation (EA) after sevoflurane based anesthesia without surgery in children.

METHODS

In a double-blinded trial, 42 children (ASA I-II,18 months to 10 years) undergoing magnetic resonance imaging (MRI) examination were randomly assigned to receive dexmedetomidine 1 microg x kg(-1) iv or placebo after induction of anesthesia. Heart rate (HR), mean arterial pressure (MAP), hemoglobin oxygen saturation (SpO2) were monitored. Anesthesia was induced in all patients, irrespective of group, with 8% sevoflurane in 50-50% O2/N2O and maintained with 1.5% sevoflurane in 50/50% O2/N2O. Agitation parameters were assessed with a 5-point scale and measured every 5 min. Delirium was defined as agitation score of > or =4 for > or =5 min. Anesthesia and procedure times and per- and postoperative side effects were recorded.

RESULTS

The HR, MAP, and SpO2, spontaneous arm or leg motion times and purposeful movement times showed no significant differences between the two groups. The time of removing the LMA, and the time of eye opening with verbal stimuli was shorter in group P than the group D (P = 0.007 and P = 0.01). The time of discharge to recovery room and the time of discharge from hospital were similar in the two groups. The mean agitation scores in the dexmedetomidine group were significantly lower than the placebo group except at 30 min (P < 0.0001, P = 0.001, P = 0.002, P = 0.013 and P = 0.001). The incidence of emergence agitation was 47.6% in group P, and 4.8% in group D (P = 0.002).

CONCLUSION

We concluded that a 1 microg x kg(-1) dose of i.v. dexmedetomidine reduces EA after sevoflurane anesthesia in children undergoing MRI.

Oral sedation with midazolam and diphenhydramine compared with midazolam alone in children undergoing magnetic resonance imaging

BACKGROUND

The purpose of this study was to compare the safety and efficacy of oral midazolam and midazolam-diphenhydramine combination to sedate children undergoing magnetic resonance imaging (MRI).

METHODS

We performed a prospective randomized double-blind study in 96 children who were randomly allocated into two groups. Group D received oral diphenhydramine (1.25 mg x kg(-1)) with midazolam (0.5 mg x kg(-1)), and Group P received oral placebo with midazolam (0.5 mg x kg(-1)) alone. Sedation scores, onset and duration of sleep were evaluated. Adverse effects, including hypoxemia, failed sedation, and the return of baseline activity, were documented.

RESULTS

Diphenhydramine facilitated an earlier onset of midazolam sedation (P < 0.01), and higher sedation scores (P < 0.01). In children who received midazolam alone, 20 (41%) were inadequately sedated, compared with 9 (18%) children who received midazolam and diphenhydramine combination (P < 0.01). Time to complete recovery was not significantly different between the two groups.

CONCLUSIONS

Our study indicates that the combination of oral diphenhydramine with oral midazolam resulted in safe and effective sedation for children undergoing MRI. The use of this combination might be more advantageous compared with midazolam alone, resulting in less sedation failure during MRI.

Sedation during regional anesthesia: inhalation versus intravenous

PURPOSE OF REVIEW

Sedation of patients either with or without regional anesthesia is discussed to ascertain sedation requirements in the two groups. The differences between 'monitored anesthesia care' and conscious sedation are defined. Several current and promising methods with which we can evaluate a patient's degree or level of sedation are assessed. Also noted are safety concerns regarding monitoring solutions for patients undergoing monitored anesthesia care. Well established techniques, including some which are decidedly 'low tech', are examined. Several routes of intravenous administration are discussed along with patient variables. Sevoflurane sedation is mentioned with regards to administration, advantages and drawbacks.

RECENT FINDINGS

Several modalities have been studied for evaluation of a patient's level of sedation, some of which have little applicability in the operating room. Processed electroencephalographic monitoring has tremendous promise but is currently not reliable enough to assess sedation level. Sevoflurane has a role in sedation, providing the limitations are understood. One drawback of sevoflurane is its greater degree of disinhibition when compared with intravenous agents, necessitating conversion to general anesthesia.

SUMMARY

Evaluating the degree of patient sedation is a need that technology has yet to meet. Several techniques have been tried in intensive care units but have little utility in the operating room. Utilization of processed electroencephalogram waveforms has the greatest potential but is of limited value at the present time. Sevoflurane is demonstrated to have a limited role in sedation but may prove useful in specific circumstances.

Pediatric sedation outside the operating room: the year in review

PURPOSE OF REVIEW

This review is a survey of the recent literature concerning issues and trends in the rapidly changing field of pediatric sedation.

RECENT FINDINGS

Clinical guidelines for the safe provision of sedation to children continue to be developed and revised. Systems for providing sedation are evolving, and the most successful models emerging are those that involve a dedicated team, either mobile or stationary, of physicians and nurses. A variety of drugs is used, and potent drugs that were designed as anesthetics, such as propofol and ketamine, are being administered outside the operating room by anesthesiologists and non-anesthesiologists. The safety of this practice continues to be debated. The reported incidence of adverse events is different in various settings and systems; however, outcome data are difficult to compare because of differences in study design and outcome definition. There is agreement that sedation is a continuum, and evidence that the depth of sedation attained during procedural sedation in children is often consistent with general anesthesia. Capnography and processed electroencephalogram monitoring have been described in sedation studies, may enhance safety during pediatric sedation, and should be investigated further.

SUMMARY

The evolution of systems, drugs, and monitors for the provision of pediatric sedation is continuing. An accurate assessment of safety and other outcomes will be enhanced through the establishment of multicenter collaborative databases.

Prevention of Emergence Agitation After Sevoflurane Anesthesia for Pediatric Cerebral Magnetic Resonance Imaging by Small Doses of Ketamine or Nalbuphine Administered Just Before Discontinuing Anesthesia

Magnetic resonance imaging (MRI) requires long-lasting immobilization that frequently can only be provided by general anesthesia in pediatric patients. Sevoflurane provides adequate anesthesia but many patients experience emergence agitation. Small doses of ketamine and nalbuphine provide moderate sedation but their benefits have subsided at the time of emergence. We hypothesized that delaying their administration until the end of the procedure would prevent emergence agitation without prolonging patient wake-up and discharge times from the postanesthesia care unit. We performed a double-blind study involving 90 patients (aged 6 mo to 8 yr) randomly allocated to 1 of 3 groups receiving either saline (S-group), ketamine (0.25 mg/kg) (K-group), or nalbuphine (0.1 mg/kg) (N-group) at the end of an MRI procedure under sevoflurane anesthesia. We evaluated emergence conditions, sedation/agitation status and completion of discharge criteria at 30 min. The three groups were comparable in age, sex ratio, physical status, and associated medical disorders. Emergence conditions did not differ significantly. There were significantly more agitated children, at all times, in the S-group and more obtunded patients at early times (5 and 10 min) in both K- and N-groups. All patients met discharge criteria at 30 min but significantly more children were awake and quiet in the K-group and still more in the N-group. In conclusion, small doses of ketamine or nalbuphine administered at the end of an MRI procedure under sevoflurane anesthesia reduce emergence agitation without delaying discharge. Nalbuphine provided better results than ketamine.

The management of infants and children for painless imaging

The ability of a child to remain sufficiently immobile for painless imaging depends upon their behaviour and the imaging itself. Anaesthesia allows imaging to be optimised but it is expensive, scarce and inappropriate for many situations. Fortunately, sedation and behavioural techniques are sufficiently successful for the majority of scanning, and success rates are high provided that suitable children are selected. Sedation, however, administered by non-anaesthetists, may have catastrophic complications such as airway obstruction. Current UK recommendations demand that any sedation technique has a 'wide margin of safety', but in addition to this, safety is dependent on trained, skillful and experienced staff. Magnetic resonance imaging frightens many children and special planning is necessary for sedation and anaesthesia. When planning an imaging service for children, all the management techniques should be considered in order to achieve maximum efficiency, quality and safety.