Comparison of propofol with pentobarbital/midazolam/fentanyl sedation for magnetic resonance imaging of the brain in children

Evaluating Sedation Strategies for Magnetic Resonance Imaging: A Comprehensive Review of Intravenous Fentanyl, Butorphanol, and Midazolam in Adult and Pediatric Populations

Magnetic resonance imaging (MRI) is a critical diagnostic tool that often requires patient sedation to ensure optimal image quality and patient comfort, particularly in those with anxiety or an inability to remain still. This comprehensive review examines the efficacy, safety, and practical considerations of three commonly used intravenous sedatives, namely, fentanyl, butorphanol, and midazolam, in adult populations undergoing MRI procedures. This review highlights the pharmacological profiles, advantages, and limitations associated with each sedative agent through a detailed analysis of current literature, clinical guidelines, and practice-based evidence. Fentanyl is noted for its potent analgesic properties and rapid onset of action, making it suitable for painful procedures. Butorphanol, with its unique opioid agonist-antagonist activity, presents an alternative with a balance between analgesia and sedation, potentially offering a safer profile for certain patient populations. Midazolam, widely recognized for its anxiolytic and amnestic effects, remains a staple in managing procedure-related anxiety. The review further discusses patient selection criteria, dosing strategies, and the importance of individualized sedation planning to enhance patient experience and procedural outcomes. Future directions highlight the potential of emerging sedation agents and non-pharmacological approaches to improve patient comfort and compliance. The findings underscore the necessity for healthcare providers to adapt sedation practices to the specific needs of each patient, considering both the clinical context and the inherent characteristics of the sedative agents. This review aims to guide clinicians in selecting the most appropriate sedation strategy for adult patients undergoing MRI, optimizing patient care and diagnostic efficacy.

Effect of esketamine vs dexmedetomidine adjunct to propofol sedation for pediatric 3Tesla magnetic resonance imaging: a randomized, double-blind, controlled trial

BACKGROUND

Adequate sedation is essential for pediatric patients undergoing 3Tesla (T) magnetic resonance imaging (MRI). Using propofol alone is associated with patient arousing and adverse airway events. This study aimed to assess esketamine vs dexmedetomidine adjunct to propofol sedation for pediatric 3 T MRI.

METHODS

In this randomized, double-blind, controlled trial, 114 pediatric patients aged between 6 months and 8 years were randomly assigned, in a 1:1 ratio, to the esketamine-propofol group or the dexmedetomidine-propofol group. Sedation was provided with esketamine or dexmedetomidine in combination with propofol titration. The primary outcome was the total dose of propofol. Secondary outcomes included propofol infusion dose, adverse events, time to emergence from sedation, and time to discharge from recovery room.

RESULTS

A total of 111 patients completed this study (56 in the esketamine-propofol group and 55 in the dexmedetomidine-propofol group). All MRI procedures were successfully performed under sedation. The total median (IQR) dose of propofol was significantly lower in the esketamine-propofol group (159.8 [121.7, 245.2] μg/kg/min) than that in the dexmedetomidine-propofol group (219.3 [188.6, 314.8] μg/kg/min) (difference in medians [95% CI] =  - 66.9 [- 87.8 to - 43.0] μg/kg/min, P < 0.0001). The use of esketamine resulted in a lower dose of propofol for titration (difference in medians [95% CI] =  - 64.3 [- 75.9 to - 51.9] μg/kg/min), a shorter time to emergence (difference in means [95% CI] =  - 9.4 [- 11.4 to - 7.4] min), and a reduced time to recovery room discharge (difference in means [95% CI] =  - 10.1 [- 12.1 to - 8.2] min). In the dexmedetomidine-propofol group, 2 patients experienced upper airway obstruction and 6 patients had bradycardia. No episodes of oxygen desaturation or other adverse events were observed.

CONCLUSIONS

Although both regimens provided effective sedation for pediatric 3 T MRI, the esketamine-propofol sedation reduced propofol requirement and facilitated recovery, without detection of increased adverse effects in the studied population. Trial registration Chinese Clinical Trial Registry (identifier: ChiCTR2100048477).

Incidence and Causes of Adverse Events in Diagnostic Radiological Studies Requiring Anesthesia in the Wake-Up Safe Registry

OBJECTIVES

General anesthesia or sedation can facilitate the completion of diagnostic radiological studies in children. We evaluated the incidence, predictors, and causes of adverse events (AEs) when general anesthesia is provided for diagnostic radiological imaging.

METHODS

Deidentified data from 24 pediatric tertiary care hospitals participating in the Wake-Up Safe registry during 2010-2015 were obtained for analysis. Children 18 years or younger receiving general anesthesia for radiological procedures were identified using Current Procedural Terminology codes, and reported AEs were analyzed if they were associated with anesthetic care at magnetic resonance imaging or computed tomography locations. Logistic regression was used to determine predictors of AE occurrence in cases with complete covariate data.

RESULTS

We identified 175,486 anesthetics for diagnostic radiological exams, compared with 83 AEs in magnetic resonance imaging or computed tomography locations (AE incidence of 0.05%). In multivariable analysis, AEs were more likely among patients with American Society of Anesthesiologists physical status IV compared with American Society of Anesthesiologists physical status I patients (adjusted odds ratio, 8.9; 95% confidence interval, 2.8-28.0; P < 0.001). Twenty-three AEs resulted in harm to the patient, whereas 32 AEs required unplanned hospital or intensive care unit admission. Anesthetic complications or issues were the most common cause of AEs (n = 52).

CONCLUSIONS

Anesthesia provided for pediatric radiological studies is very safe and with an overall low AE incidence. The contribution of anesthetic complications to reported AEs suggests opportunities for further process improvement in this setting.

Lower-Dose Propofol Use for MRI: A Retrospective Review of a Pediatric Sedation Team's Experience

OBJECTIVE

The aim of the study was to evaluate, in children undergoing procedural sedation for magnetic resonance imaging (MRI) scans, whether lower doses of propofol than previously published permitted a high rate of successful MRI completion, whether lower dosages result in a more rapid recovery, and whether age or behavioral diagnosis increases propofol requirements.

METHODS

After institutional review board approval, we retrospectively reviewed the pediatric sedation team's sedation database of children receiving propofol infusion for MRI scans between 2007 and 2016. Data collected included propofol induction dose (in milligrams per kilogram), propofol infusion dose (in micrograms per kilogram per hour), total propofol dose (in milligrams per kilogram and in milligrams per kilogram per hour), and the number of administered ancillary sedative medications. Additional data included the American Society of Anesthesiologist status, sedation duration, recovery duration, and successful completion of MRI. Dosing data were also stratified by age.

RESULTS

A total of 2354 patients met inclusion criteria. Eight percent of patients received propofol infusion alone, 79% received midazolam before their propofol induction, and 13% received a combination of propofol and other drugs. Mean induction dose was 2.2 + 0.9 mg/kg, mean infusion dose was 93.5 + 29.0 μg/kg per minute, and total mean dose was 9.0 + 3.0 mg/kg per hour. Mean recovery time was 44 minutes, and 99.3% of the scans were completed with good images. We noted an increase requirement in the mean induction dose and total dose in children younger than 1 year.

CONCLUSIONS

Propofol infusion doses lower than commonly reported permit successful completion of scans and similar recovery times in a single institution. Younger children require more propofol for successful procedural sedation.

Creation and Implementation of a Hospitalist-Run Propofol Sedation Program

BACKGROUND

Pediatric hospitalists increasingly provide sedation outside the operating room. Given the large body of safety data available, propofol was identified as a beneficial addition to our hospitalist-run sedation service's medication repertoire. Currently, the training required for hospitalists to provide sedation is defined and determined locally by individual institutions.

METHODS

We convened a task force to develop and implement training for hospitalists in the use of propofol for deep sedation. After implementing training, we analyzed the outcome of patients receiving propofol for deep sedation for MRI, including the adverse event rate and successful completion rate. An adverse event was defined as a significant desaturation, persistent upper airway obstruction, laryngospasm, administration of neuromuscular blockade, conversion to anesthesia, call for additional backup, or if the procedure was not able to be completed. Successful completion was defined as any patient being able to complete the imaging study or procedure with sedation performed by a hospitalist physician.

RESULTS

Between September 2015 and September 2018, sedation services sedated 12 979 patients, 3929 of whom were deeply sedated with propofol. During this period, the trained hospitalists had an adverse event rate of 3.6% and a 98.9% rate of successful completion of all studies or procedures when using propofol for deep sedation.

CONCLUSION

With a comprehensive training program for hospitalists in the administration of propofol, we provided effective sedation for a selective population of patients. We now have a standard approach that uses credentialed hospitalists to train new faculty for propofol administration.

Validation of the Ramsay scale for invasive procedures under deep sedation in pediatrics

BACKGROUND

The Ramsay scale is the most widely used scale during pediatric procedures although it has not been formally validated.

OBJECTIVE

To validate the Ramsay scale during invasive procedures under sedation in pediatrics.

METHODS

A prospective analytic study was conducted in two hospitals. All patients ≥6 months that were undergoing invasive procedures under sedation were enrolled. All were recorded, and these videos were edited and randomized. 150 videos were scored by four observers (a pediatrician, a pediatric intensive care unit nurse, an anesthetist, and an operating room nurse). All videos were scored with the Ramsay scale and University of Michigan Sedation Scale. Observers were blinded to drug administration. Construct validity was measured through Wilcoxon test paired samples after administration of sedatives. Criterion validity, intra-observer reliability, and interobserver correlation were evaluated by comparing the scores of the scales using Spearman's correlation coefficient. Interobserver agreement was measured using the intraclass correlation coefficient. To assess test-retest reliability, 50 videos were randomly selected and reevaluated.

RESULTS

Sixty-five patients were included. Construct validity was demonstrated through changes in the Ramsay scale scoring after administration of sedatives (p < .0001). Regarding criterion validity, the Ramsay scale had a high correlation with the UMSS (ρ = 0.621). Intra-observer agreement was ρ = 0.884. The Ramsay scale showed interobserver reliability with an intraclass correlation coefficient = 0.94 when comparing it with the University of Michigan Sedation Scale. Internal consistency was α = 0.91. Regarding applicability, in our study, it was applied in two hospitals in different areas by four professionals from distinct categories.

CONCLUSIONS

The Ramsay scale is valid, reliable, and applicable to monitoring sedation for invasive procedures under deep sedation in pediatrics.

Independent risk factors for adverse events associated with propofol-based pediatric sedation performed by anesthesiologists in the radiology suite: a prospective observational study

This study aimed to identify the types and frequencies of adverse events, as well as the risk factors for respiratory complications related to pediatric sedation. This single-center, prospective, observational study was conducted in a radiology suite at a tertiary university hospital for 2 years. Patients aged under 18 years, who underwent sedation solely by anesthesiologists for computed tomography or magnetic resonance imaging scans, were eligible for inclusion. Univariate and multivariate logistic regression analyses were carried out to identify the risk factors of adverse events, including respiratory complications, related to the propofol-based sedation. We further performed a sensitivity test with 1-to-5 propensity score matching analysis to assess the robustness of our findings. Among 2569 children, 3.9% experienced respiratory problems related to the sedation. After 1-to-5 propensity matching analysis, cardiac and neurologic comorbidities, crying before sedation, a history of snoring or upper respiratory infection, and prolonged duration of sedation were independently associated with the occurrence of adverse respiratory events.Conclusions: Our protocol for pediatric sedation demonstrates a high success rate and low likelihood of fatal complications, but proactive management prior to propofol-based sedation is critical to prevent adverse respiratory events in children. What is Known: • Propofol-based pediatric sedation is associated with adverse events necessarily even though performed by professional anesthesiologists solely. What is New: • Cardiac and neurologic comorbidities, crying before sedation, a history of snoring or upper respiratory infection, and prolonged duration of sedation were independently associated with the occurrence of respiratory adverse events. • Proactive management prior to sedation is critical to preventing adverse respiratory events for pediatrics.

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 infants 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.

Evaluation of the safety of using propofol for paediatric procedural sedation: A systematic review and meta-analysis

Propofol is one of the most widely used drugs for paediatric procedural sedation owing to its known advantages, but some concerns remain regarding respiratory and/or cardiac complications in patients receiving propofol. Although a considerable number of randomised controlled clinical trials (RCTs) have been conducted to compare it with other sedative agents or opioids for children undergoing various procedures, propofol is still being used off-label for this indication in many countries. We performed a systematic review and meta-analysis of those RCTs to provide an overall summation of evidence that can potentially be considered for further regulatory decisions, including reimbursement policies. We searched for RCTs in MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from their inception to January 31, 2018. Our meta-analysis of 30 RCTs confirmed that propofol sedation had advantages in recovery time when compared with other drugs, without excessive concerns for cardiovascular or respiratory adverse events. Its safety profile regarding coughing, nausea or vomiting, and emergence delirium was also similar to that of other drugs. The overall evidence suggests that propofol sedation for paediatric procedures should be considered more positively in the context of regulatory decisions.

Propofol Versus Dexmedetomidine for Procedural Sedation in a Pediatric Population

OBJECTIVES

Frequently, infants and children require sedation to facilitate noninvasive procedures and imaging studies. Propofol and dexmedetomidine are used to achieve deep procedural sedation in children. The objective of this study was to compare the clinical safety and efficacy of propofol versus dexmedetomidine in pediatric patients undergoing sedation in a pediatric sedation unit.

METHODS

A retrospective analysis of patients sedated with either propofol or dexmedetomidine in a pediatric sedation unit by pediatric emergency physicians was performed. Both medications were dosed per protocol with propofol 2 mg/kg induction and 150 μg · kg^-1 · min^-1 maintenance and dexmedetomidine 3 μg/kg induction for 10 minutes and 2 μg · kg^-1 · h^-1maintenance. The variables collected included drug dose, sedation time (time that the drug was given to the completion of the procedure), recovery time (end of the study to the return to the presedation sedation score for 15 minutes), need for dose rate changes, airway management, and adverse events.

RESULTS

A total of 2432 children were included- 1503 who received propofol and 929 who received dexmedetomidine. Propofol and dexmedetomidine resulted in successful completion of the study in 98.8% and 99.7%, respectively (P = 0.02). The mean recovery time for propofol was 34.3 minutes, compared with 65.6 minutes for dexmedetomidine (P < 0.001). The need for unexpected airway management was 9.7% for propofol and 2.2% for dexmedetomidine (P < 0.001). Adverse events occurred in 8.6% and 6% of patients in the propofol and dexmedetomidine groups, respectively (P = 0.02).

CONCLUSIONS

Propofol use led to significantly shorter recovery times, with an increased need for airway management, but rates of bag-mask ventilation (2.3%), airway obstruction (1.1%), and desaturation (1.6%) were low. No patients required intubation. Propofol is a reasonable alternative to dexmedetomidine, with a clinically acceptable safety profile.

Total cerebrovascular blood flow and whole brain perfusion in children sedated using propofol with or without ketamine at induction: An investigation with 2D-Cine PC and ASL

BACKGROUND

Multiple sedation regimes may be used to facilitate pediatric MRI scans. These regimes might affect cerebral blood flow and hemodynamics to varying degrees, particularly in children who may be vulnerable to anesthetic side effects.

PURPOSE

To compare the effects of propofol monosedation solely (Pm group) vs. a combination of propofol and ketamine (KP group) on brain hemodynamics and perfusion.

STUDY TYPE

Prospective double-blind randomized trial.

FIELD STRENGTH/SEQUENCES

1.5T and 3T. 2D-Cine phase contrast (2D-Cine PC) and pseudocontinuous arterial spin labeling (ASL).

POPULATION

Children aged from 3 months to 10 years referred for MRI with deep sedation were randomized into either the KP or the Pm group. Perfusion images were acquired with ASL followed by single-slice 2D-Cine PC acquired between the cervical vertebra C2 and C3.

ASSESSMENT

Average whole-brain perfusion (WBP ml.min^-1 .100 ml^-1 ) was extracted from the ASL perfusion maps and total cerebrovascular blood flow (CVF) was quantified by bilaterally summing the flow in the vertebral and the internal carotid arteries. The CVF values were converted to units of ml.min^-1 .100 g^-1 to calculate the tissue CVF_100g (ml.min^-1 .100 g^-1 ). Images were assessed by a neuroradiologist and data from n = 81 (ASL) and n = 55 (PC) cases with no apparent pathology were entered into the analysis.

STATISTICAL TESTS

Multivariate analysis of covariance was performed to compare drug sedation effects on WBP, CVF, and CVF_100g .

RESULTS

No significant difference in arterial flow was observed (P = 0.57), but the KP group showed significantly higher WBP than the Pm group, covarying for scanner and age (P = 0.003). A correlation analysis showed a significant positive correlation between mean WBP (ml.min^-1 .100 g^-1 ) and mean CVF_100g .

DATA CONCLUSION

The KP group showed higher perfusion but no significant difference in vascular flow compared with the Pm group. WBP and CVF_100g correlated significantly, but ASL appeared to have more susceptibility to perfusion differences arising from the different sedation regimes.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;50:1433-1440.

A Simulation Study of Propofol Effect-Site Concentration for Appropriate Sedation in Pediatric Patients Undergoing Brain MRI: Pharmacodynamic Analysis

PURPOSE

We aimed to establish the propofol effect-site concentration (Ce) for appropriate sedation by pharmacodynamic analysis and to determine the propofol Ce during occurrence of sedation-related side effects in pediatric patients undergoing brain magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In 50 pediatric patients scheduled for brain MRI, sedation was induced with 2.0 mg/kg propofol; additional propofol doses were 0.5-1 mg/kg. Propofol Ce was simulated by inputting the propofol administration profiles of patients into a pediatric compartmental model (Choi model). The relationship between propofol Ce and probabilities of sedation and recovery were analyzed using a sigmoidal Emax model. The simulated propofol Ce for sedation-related side effects was investigated. Population model parameters were estimated using the Nonlinear Mixed-Effects Modelling software.

RESULTS

The mean values of propofol Ce₅₀ for sedation during the preparation, scanning, and recovery phases were 1.23, 0.43, and 0.39 μg/mL. The simulated propofol Ce values during oxygen desaturation (SpO₂ <90%) (3 patients; 6%), hypotension (16 patients; 32%), and bradycardia (12 patients; 24%) were 3.01±0.04, 2.05±0.63, and 2.41±0.89 μg/mL, respectively.

CONCLUSION

The required propofol Ce₅₀ for applying monitors during the preparation phase before the start of MRI was higher than the propofol Ce₅₀ required during the scanning phase. During low-intensity stimulation phases, such as scanning, propofol bolus dose should be strictly titrated not to exceed the propofol Ce that can lead to oxygen desaturation because of the relatively low propofol Ce (Ce₉₅, 1.43 μg/mL) required for sedation in most patients.

Sedation and analgesia for procedures in the pediatric emergency room

OBJECTIVE

Children and adolescents often require sedation and analgesia in emergency situations. With the emergence of new therapeutic options, the obsolescence of others, and recent discoveries regarding already known drugs, it became necessary to review the literature in this area.

DATA SOURCES

Non-systematic review in the PubMed database of studies published up to December 2016, including original articles, review articles, systematic reviews, and meta-analyses. References from textbooks, publications from regulatory agencies, and articles cited in reviews and meta-analyses through active search were also included.

DATA SYNTHESIS

Based on current literature, the concepts of sedation and analgesia, the necessary care with the patient before, during, and after sedoanalgesia, and indications related to the appropriate choice of drugs according to the procedure to be performed and their safety profiles are presented.

CONCLUSIONS

The use of sedoanalgesia protocols in procedures in the pediatric emergency room should guide the professional in the choice of medication, the appropriate material, and in the evaluation of discharge criteria, thus assuring quality in care.

A retrospective comparison of propofol alone to propofol in combination with dexmedetomidine for pediatric 3T MRI sedation

BACKGROUND AND AIM

Both propofol and dexmedetomidine have been found to be safe and effective sedation for magnetic resonance imaging (MRI). Our program experienced an increase in patients arousing and experiencing an adverse airway event during propofol sedation for MRI in the first months of using a new 3T (Tesla) MRI scanner that was found to have a longer reverberation time compared to the previous 1.5 T MRI. In an effort to decrease patient arousal and adverse airway events during MRI, we administered a dexmedetomidine load prior to our standard propofol protocol. The objective was to compare adverse events and other outcome measures of patients sedated with propofol alone (Pro) and propofol preceded by a dexmedetomidine load (D+P).

METHODS

We reviewed a sedation database and medical records for all children undergoing 3T MRI studies while sedated with propofol alone or propofol preceded by a dexmedetomidine load in 2014.

RESULTS

Two hundred and fifty-six sedations were performed for MRI (87 Pro and 169 D+P). The two groups were comparable with regard to age, weight, gender, and American Society of Anesthesiologists status. Subjects in the D+P cohort had significantly fewer adverse events (10/169 patients (5.9%) vs 23/87 patients (26.4%) [OR 0.18, 95% CI: 0.08-0.39, P < 0.001]), particularly upper airway obstruction. Mean discharge time was longer in the D+P cohort compared to the Pro cohort (87.1, SD 26.3 min vs 69.7, SD 23.6; [mean difference 17.7 min, 95% CI: 10.6-24.8, P < 0.001]).

CONCLUSIONS

The addition of a dexmedetomidine infusion prior to our propofol MRI sedation protocol resulted in fewer sedation-related adverse events, particularly upper airway obstruction. Further studies are needed to evaluate the potential for a reduction on adverse events with this drug combination.

Dexmedetomidine versus Propofol: Is One Better Than the Other for MRI Sedation in Children?

Objective The aim of this article is to determine whether dexmedetomidine or propofol is better for MRI sedation in children. Design This study is a retrospective review of patients sedated with dexmedetomidine or propofol for MRI between July 2007 and July 2015. Dexmedetomidine group (group D) was administered a bolus of 2 µg/kg over 10 minutes followed by a 1 ug/kg/hour infusion. Propofol group (group P) received a bolus of 2 mg/kg over 2 minutes followed by 83 µg/kg/minute infusion. Results Of the 996 cases completed, 452 were in group P and 544 were in group D. Patients in group P were heavier and older than those in group D. All the patients except one in group D completed the procedures. Hypotension occurred in 59% in group P versus 4% in group D (89 ± 11.4 SBP vs. 103.80 ± 19.4; p < 0.05). Bradycardia was observed in 2.9% in group P versus 0.6% in group D. Apnea occurred in two patients in group D. Although procedure time was longer in patients receiving propofol versus dexmedetomidine (58.87 ± 28.17 vs. 45 ± 23.6; p < .05), the discharge time was significantly shorter (37. ± 12.30 vs. 92.61 ± 28.19; p < 0.05). Conclusion Dexmedetomidine appears to provide a useful alternative to propofol for MRI sedation with a longer recovery time, stable hemodynamics, and less reliable respiratory profile, while the propofol had the advantage of quicker onset and rapid recovery.

Memory and hippocampal architecture following short-term midazolam in western diet-treated rats

The impact of short-term benzodiazepine exposure on cognition in middle-aged or older patients is a highly debated topic among anesthesiologists, critical care physicians and public media. "Western diet" (WD) consumption is linked to impaired cognition as well. The combination of benzodiazepines with substantial exposure to WD might set the stage for increased hippocampal vulnerability for benzodiazepines leading to exaggerated cognitive impairment in the postoperative period. In this study, Fischer 344 rats were fed either WD or standard rodent diet from 5 to 10.5 months of age. Rats were exposed to midazolam or placebo two days prior to an MRI scan using Diffusional Kurtosis Imaging (DKI) to assess brain microstructural integrity, followed by behavioral testing using a water radial arm maze. Hippocampal tissue was collected to assess alterations in protein biochemistry in brain regions associated with learning and memory. Our results showed that rats exposed to the combination of midazolam and WD had significantly delayed time of learning and exhibited spatial memory impairment. Further, we observed an overall increase of kurtosis metrics in the hippocampus and increased expression of the mitochondrial protein VDAC2 in midazolam-treated rats. Our data suggest that both the short-acting benzodiazepine midazolam and WD contribute to negatively affect the brain in middle-aged rats. This study is the first application of DKI on the effects of midazolam and WD exposure, and the findings demonstrate that diffusion metrics are sensitive indicators of changes in the complexity of neurite architecture.

Practice advisory on anesthetic care for magnetic resonance imaging: an updated report by the american society of anesthesiologists task force on anesthetic care for magnetic resonance imaging

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Anesthetic Care for Magnetic Resonance Imaging presents an updated report of the Practice Advisory on Anesthetic Care for Magnetic Resonance Imaging.

Supplemental Digital Content is available in the text.

Propofol anesthesia for children undergoing magnetic resonance imaging: a comparison with isoflurane, nitrous oxide, and a laryngeal mask airway

BACKGROUND

Both propofol infusions with oxygen delivered through nasal cannula and isoflurane/N2O (nitrous oxide) delivered via a laryngeal mask airway (LMA) are used to provide anesthesia for children undergoing magnetic resonance imaging scans. We compared the incidence of adverse events and perioperative physiologic responses in children anesthetized with these 2 regimens.

METHODS

One hundred-fifty healthy children, ages 1 to 10 years, were randomized to receive either a propofol infusion (starting at 300 µg kg·min) with oxygen via nasal cannula (n = 75) or isoflurane with 70% N2O in oxygen delivered via an LMA (n = 75), both after a sevoflurane/N2O/oxygen induction. Adverse airway events, as well as hemodynamic, respiratory, and other physiologic responses were recorded during the magnetic resonance imaging scans and in the postanesthesia care unit by a single research nurse who was blind to the treatments. All parents were contacted postoperatively to complete a postanesthetic follow-up.

RESULTS

All 150 children completed their scans. The frequency of all adverse airway events during emergence and recovery after propofol (12%) was significantly less than that after isoflurane/N2O/LMA (49%) (95% confidence interval for the risk difference was 23%-50%) (P = 0.0001). Hemodynamic responses and recovery times for the 2 treatments were similar. Early recovery, defined as the time interval from admission to the postanesthesia care unit until eye opening and wakefulness (modified Aldrete score >5), after propofol was more rapid than that after isoflurane/N2O/LMA (P = 0.0001 and P = 0.0012, respectively). No scans had to be repeated.

CONCLUSIONS

The frequency of adverse airway events during emergence and recovery after propofol infusion with oxygen by nasal cannula is less than with isoflurane/N2O/LMA in children.

At what age range should children be circumcised?

Background:

Although male circumcision is a surgical intervention that is frequently performed in children, there is no consensus about the age at which it should be performed.

Objectives:

The purpose of this study was to determine the best age range for routine male circumcision with respect to a child’s health and the cost.

Patients and Methods:

This clinical trial was conducted in the affiliated hospital of the Erzincan University of Medical Sciences, Turkey, in 2014. The circumcised children were evaluated in 3 groups: < 1 year old (Group 1), 1-7 years old (Group 2), and > 7 years old (Group 3). To obtain a satisfactory Wilton sedation score, midazolam 0.1 mg/kg IV was administered first. If adequate sedation was not achieved, ketamine 2 mg/kg IV was also administered. If adequate sedation was still not achieved, general anesthesia was administered via a laryngeal mask. At the end of the surgery, the groups were compared in terms of post-anesthesia recovery duration, complications, discharging duration, and cost.

Results:

A total of 603 children were circumcised, 374 in Group 1, 94 in Group 2, and 135 in Group 3. Midazolam was sufficient for sedation in 364 Group 1 patients (97.3%), 6 Group 2 patients (6.3%), and 38 Group 3 patients (28.1%). The shortest post-anesthesia recovery duration after surgical intervention and time until discharge, the lowest cost, and the fewest anesthesia complications were observed in Group 1 (P < 0.05 for all).

Conclusions:

Although almost all of the < 1 year-old children could be sedated with midazolam alone, most of the > 1 year-old children required ketamine or general anesthesia. Performing circumcision when children are less than 1 year old decreases the risk of complications due to anesthesia and lowers the costs compared with performing the procedure on older children.

A presedation fluid bolus does not decrease the incidence of propofol-induced hypotension in pediatric patients

BACKGROUND AND OBJECTIVE

Propofol is commonly used in pediatric sedation, which may cause hypotension during induction. Our goal was to determine the effect of a preinduction 20-mL/kg isotonic fluid bolus on propofol-induced hypotension, assess clinical signs of hypoperfusion during hypotension, and evaluate for age-related propofol dosing differences.

METHODS

This prospective, randomized, controlled, nonblinded study was conducted at Children's Hospital of Illinois. Patients were children 6 to 60 months of age who needed sedation for MRI or auditory brainstem-evoked response testing. The treatment group received a preinduction 20-mL/kg isotonic saline bolus before procedure initiation. Patients were continuously monitored via cardiorespiratory monitor with pulse oximetry and end-tidal carbon dioxide measurements. Cardiovascular indices and clinical signs of hypoperfusion were compared between groups, and propofol dosing differences were compared between age groups.

RESULTS

One hundred twenty-six patients were randomly assigned to treatment (n=52) or control (n=74) conditions. Twelve patients in the treatment group and 14 patients in the control group experienced postinduction hypotension, as defined by the Pediatric Advanced Life Support guidelines. One patient in each group was given volume resuscitation when blood pressure did not improve after a reduction in the propofol infusion rate. No hypotensive patients had physical signs of hypoperfusion, and patients≤1 year of age needed significantly more propofol.

CONCLUSIONS

A 20-mL/kg preinduction isotonic saline bolus does not prevent propofol-induced hypotension. No clinical signs of hypoperfusion were noted with induced hypotension, and infants≤12 months old need significantly more propofol per kilogram for procedures.

High dose dexmedetomidine: effective as a sole agent sedation for children undergoing MRI

Objective. To determine the efficacy and safety of high dose dexmedetomidine as a sole sedative agent for MRI. We report our institution's experience. Design. A retrospective institutional review of dexmedetomidine usage for pediatric MRI over 5.5 years. Protocol included a dexmedetomidine bolus of 2 μg/kg intravenously over ten minutes followed by 1 μg/kg/hr infusion. 544 patients received high dose dexmedetomidine for MRI. A second bolus was used in 103 (18.9%) patients. 117 (21.5%) required additional medications. Efficacy, side effects, and use of additional medicines to complete the MRI were reviewed. Data was analyzed using Student's t-test, Fisher's exact test, and Analysis of Variance (ANOVA). Main Results. Dexmedetomidine infusion was associated with bradycardia (3.9%) and hypotension (18.4%). None of the patients required any intervention. Vital signs were not significantly different among the subgroup of patients receiving one or two boluses of dexmedetomidine or additional medications. Procedure time was significantly shorter in the group receiving only one dexmedetomidine bolus and increased with second bolus or additional medications (P < 0.0001). Discharge time was longer for children experiencing bradycardia (P = 0.0012). Conclusion. High dose Dexmedetomidine was effective in 78.5% of cases; 21.5% of patients required additional medications. Side effects occurred in approximately 25% of cases, resolving spontaneously.

Pediatric critical care physician-administered procedural sedation using propofol: a report from the Pediatric Sedation Research Consortium Database

OBJECTIVE

Increasing demand for pediatric procedural sedation has resulted in a marked increase in provision of pediatric procedural sedation by pediatric critical care physicians both inside and outside of the ICU. Reported experience of pediatric critical care physicians-administered pediatric procedural sedation is limited. We used the Pediatric Sedation Research Consortium database to evaluate a multicenter experience with propofol by pediatric critical care physicians in all settings.

SETTING

Review of national Pediatric Sedation Research Consortium database to identify pediatric procedural sedation provided by pediatric critical care physicians from 2007 to 2012. Demographic and clinical data were collected to describe pediatric procedural sedation selection, location, and delivery. Multivariable logistic regression analysis was performed to identify risk factors associated with pediatric procedural sedation-related adverse events and complications.

MEASUREMENTS AND MAIN RESULTS

A total of 91,189 pediatric procedural sedation performed by pediatric critical care physicians using propofol were included in the database. Median age was 60.0 months (range, 0-264 months; interquartile range, 34.0-132.0); 81.9% of patients were American Society of Anesthesiologists class I or II. Most sedations were performed in dedicated sedation or radiology units (80.9%). Procedures were successfully completed in 99.9% of patients. A propofol bolus alone was used in 52.8%, and 41.7% received bolus plus continuous infusion. Commonly used adjunctive medications were lidocaine (35.3%), opioids (23.3%), and benzodiazepines (16.4%). Overall adverse event incidence was 5.0% (95% CI, 4.9-5.2%), which included airway obstruction (1.6%), desaturation (1.5%), coughing (1.0%), and emergent airway intervention (0.7%). No deaths occurred; a single cardiac arrest was reported in a 13-month-old child receiving propofol and ketamine, with no untoward neurologic sequelae. Risk factors associated with adverse event included: location of sedation, number of adjunctive medications, upper and lower respiratory diagnosis, prematurity diagnosis, weight, American Society of Anesthesiologists status, and painful procedure.

CONCLUSIONS

Pediatric procedural sedation using propofol can be provided by pediatric critical care physicians effectively and with a low incidence of adverse events.

A randomized trial evaluating low doses of propofol infusion after intravenous ketamine for ambulatory pediatric magnetic resonance imaging

Objective:

Our study compared the discharge time after pediatric magnetic resonance imaging (MRI) following sedation with propofol infusion dose of 100, 75 and 50 mcg/kg/min given after a bolus dose of ketamine and propofol.

Materials and Methods:

One hundred children of American Society of Anesthesiologists status 1/2, aged 6 months to 8 years, scheduled for elective MRI were enrolled and randomized to three groups to receive propofol infusion of 100, 75 or 50 mcg/kg/min (Groups A, B, and C, respectively). After premedicating children with midazolam 0.05 mg/kg intravenous (i.v.), sedation was induced with bolus dose of ketamine and propofol (1 mg/kg each) and the propofol infusion was connected. During the scan, heart rate, noninvasive blood pressure, respiratory rate, and oxygen saturation were monitored.

Results:

The primary outcome that is, discharge time was shortest for Group C (44.06 ± 18.64 min) and longest for Group A (60.00 ± 18.66 min), the difference being statistically and clinically significant. The secondary outcomes that is, additional propofol boluses, scan quality and awakening time were comparable for the three groups. The systolic blood pressure at 20, 25 and 30 min was significantly lower in Groups A and B compared with Group C. The incidence of sedation related adverse events was highest in Group A and least in Group C.

Conclusion:

After a bolus dose of ketamine and propofol (1 mg/kg each), propofol infusion of 50 mcg/kg/min provided sedation with shortest discharge time for MRI in children premedicated with midazolam 0.05 mg/kg i.v. It also enabled stable hemodynamics with less adverse events.

Pediatric procedural sedation with propofol using a higher initial bolus dose

OBJECTIVES

We sought to describe the doses of propofol used for sedation in our pediatric emergency department, along with the range of procedures performed under propofol sedation. We also planned to describe clinically important physiologic changes seen and physician satisfaction with propofol at the doses observed.

METHODS

This was a prospective observational case series. Physicians completed a data collection form after the propofol sedation. The physicians were asked to report physiologic changes that occurred during sedation and rate their satisfaction with propofol as a sedation agent on a 100-mm visual analog scale.

RESULTS

Eight hundred eighty-six sedation events were reported. The median initial dose of propofol given was 2.0 mg/kg and the median total dose was 3.6 mg/kg. Propofol was used for a wide range of procedures. The most common physiologic change was desaturation/hypoxia (desaturation to <90% in 7.2%). No deaths, unplanned intubations, or surgical airway placements were reported. Treating physicians reported a median satisfaction score of 97 mm.

CONCLUSIONS

A 2-mg/kg initial bolus dose of propofol for pediatric sedation was well tolerated and useful for a wide range of procedures. Physicians should expect to find a high level of satisfaction with this dose.

BOLD fMRI in infants under sedation: Comparing the impact of pentobarbital and propofol on auditory and language activation

PURPOSE

To elucidate differences in the disruption of language network function, as measured by blood oxygenation level-dependent (BOLD) contrast functional MRI (fMRI), attributable to two common sedative agents administered to infants under clinical imaging protocols.

MATERIALS AND METHODS

The sedatives pentobarbital (Nembutal) and Propofol, administered clinically to infants at 1 year of age, were compared with respect to BOLD activation profiles in response to passive story-listening stimulation. An intermittent event-related imaging protocol was used with which the temporal evolution of language processing resulting from this stimulation was explored.

RESULTS

Propofol and Nembutal were found to have distinct and complementary responses to story-listening. Propofol exhibited more activation in higher processing networks with increasing response toward the end of narrative stimulus. Nembutal, in contrast, had much more robust activation of primary and secondary sensory cortices but a decreasing response over time in fronto-parietal default-mode regions. This may suggest a breakdown of top-down feedback for Propofol versus the lack of bottom-up feed-forward processing for Nembutal.

CONCLUSION

Two popular sedative agents for use in children for clinical fMRI were found to induce distinct alteration of activation patterns from a language stimulus. This has ramifications for clinical fMRI of sedated infants and encourages further study to build a framework for more confident interpretation.

Analysis of procedural sedation provided by pediatricians

BACKGROUND

Pediatric procedural sedation outside of the operating room is performed by a variety of pediatric specialists. Using the database from the Pediatric Sedation Research Consortium (PSRC), patient demographics, medications used, diagnoses, complications, and procedures involved when pediatricians provided sedation in this cohort, were described. 'Pediatrician' was defined as a general pediatrician, cardiologist, endocrinologist, gastroenterologist, hematologist/oncologist, neurologist, pulmonologist or hospitalist.

METHODS

Data were collected by the PSRC, a group of 35 institutions dedicated to improving sedation care for children. Members prospectively enrolled consecutive patients who received sedation or anesthesia for diagnostic or therapeutic procedures. Data on demographics, primary diagnoses, procedures, medications, interventions, and complications were collected and stored on a Web-based data collection tool.

RESULTS

A total of 12 113 sedations performed by pediatricians were submitted from 1 July 2004 to 31 December 2008, compared to 119 665 cases performed by non-pediatricians. Pediatrician patients were more frequently non-emergency American Society of Anesthesiologists (ASA) class I or II, aged 2-8 years old, with a neurologic primary diagnosis, being sedated for a radiologic procedure with a sedative. Distraction techniques were used more frequently in the pediatrician group (11.9% vs 3.1%). The most common complication encountered was inadequate sedation, which occurred 2.2% of the time.

CONCLUSIONS

Pediatricians sedate for a variety of patients within the PSRC, but the patients tended to be younger, predominately ASA class I or II, non-emergency, and undergoing non-painful procedures when compared to non-pediatrician providers. The patient demographics, medications used, diagnoses, complications, and procedures involved varied between the groups significantly. Complication rates were similar between the groups.

Bayesian Hierarchical Modeling for Categorical Longitudinal Data from Sedation Measurements

We investigate a Bayesian hierarchical model for the analysis of categorical longitudinal data from sedation measurement for Magnetic Resonance Imaging (MRI) and Computerized Tomography (CT). Data for each patient is observed at different time points within the time up to 60 min. A model for the sedation level of patients is developed by introducing, at the first stage of a hierarchical model, a multinomial model for the response, and then subsequent terms are introduced. To estimate the model, we use the Gibbs sampling given some appropriate prior distributions.

Relief of pain and anxiety in pediatric patients in emergency medical systems

Control of pain and stress for children is a vital component of emergency medical care. Timely administration of analgesia affects the entire emergency medical experience and can have a lasting effect on a child's and family's reaction to current and future medical care. A systematic approach to pain management and anxiolysis, including staff education and protocol development, can provide comfort to children in the emergency setting and improve staff and family satisfaction.

Complications of three deep sedation methods for magnetic resonance imaging

Background:

Propofol and pentobarbital are commonly used to sedate children undergoing magnetic resonance imaging (MRI).

Aim/Objective:

To compare the safety of three types of sedation: intravenous propofol (PROP), mixed pentobarbital/propofol (PENT), and mixed pentobarbital group requiring supplemental sedation (PENT SUPP) regimens in pediatric patients following deep sedation (DS) for noncardiac MRI.

Materials and Methods:

We conducted a case-control study matching 619 cases with complications with 619 controls using data from our institution's sedation database for children deeply sedated for noncardiac MRI. Cases were defined as patients with any complication and we characterized complications from cases, and used a conditional logistic regression model to assess the association between three DS methods and occurrence of complications after adjusting for confounding variables.

Results:

We found that complications occurred in association with 794 (10.1%) of the 7,839 DSs performed for MRI between 1998 and 2008. Of the 794 cases, 619 cases met inclusion criteria for the study. Among the 619 cases that met inclusion criteria, 24 (0.3% of 7,839 DSs total) were associated with major complications. Type of sedation was significantly associated with the occurrence of complications, and the PENT group was associated with decreased odds of complications when compared to the PROP regimen (OR 0.68; 95% CI 0.46, 0.98; P=0.040) and compared to the PENT SUPP group (OR 0.60; 95% CI 0.31, 0.89; P<0.0001).

Conclusions:

DS with a pentobarbital technique was associated with decreased odds for complications when compared to a propofol-based technique or a pentobarbital technique requiring supplemental sedation.

Empirical evaluation of age groups and age-subgroup analyses in pediatric randomized trials and pediatric meta-analyses

BACKGROUND

An important step toward improvement of the conduct of pediatric clinical research is the standardization of the ages of children to be included in pediatric trials and the optimal age-subgroups to be analyzed.

METHODS

We set out to evaluate empirically the age ranges of children, and age-subgroup analyses thereof, reported in recent pediatric randomized clinical trials (RCTs) and meta-analyses. First, we screened 24 RCTs published in Pediatrics during the first 6 months of 2011; second, we screened 188 pediatric RCTs published in 2007 in the Cochrane Central Register of Controlled Trials; third, we screened 48 pediatric meta-analyses published in the Cochrane Database of Systematic Reviews in 2011. We extracted information on age ranges and age-subgroups considered and age-subgroup differences reported.

RESULTS

The age range of children in RCTs published in Pediatrics varied from 0.1 to 17.5 years (median age: 5; interquartile range: 1.8-10.2) and only 25% of those presented age-subgroup analyses. Large variability was also detected for age ranges in 188 RCTs from the Cochrane Central Register of Controlled Trials, and only 28 of those analyzed age-subgroups. Moreover, only 11 of 48 meta-analyses had age-subgroup analyses, and in 6 of those, only different studies were included. Furthermore, most of these observed differences were not beyond chance.

CONCLUSIONS

We observed large variability in the age ranges and age-subgroups of children included in recent pediatric trials and meta-analyses. Despite the limited available data, some age-subgroup differences were noted. The rationale for the selection of particular age-subgroups deserves further study.

High-dose dexmedetomidine sedation for pediatric MRI

OBJECTIVES

To test the hypothesis that high-dose dexmedetomidine can be successfully used for pediatric magnetic resonance imaging (MRI) sedation without significant hemodynamic compromise.

BACKGROUND

The dexmedetomidine dose required to achieve optimal sedation is often higher than its recommended dose. High doses of dexmedetomidine can lead to significant hemodynamic side effects.

METHODS

Dexmedetomidine use for pediatric MRI over a 1-year period was retrospectively reviewed. A dexmedetomidine bolus of 2 μg·kg(-1) intravenous followed by 1 μg·kg(-1)·h(-1) infusion was used. Dexmedetomidine efficacy, side effects, timing of side effects, and additional use of medications were analyzed. Data were compared by t-test, Mann-Whitney rank-sum test, Fisher's exact test, and anova.

RESULTS

High-dose dexmedetomidine was used in 77 patients, and MRI was completed in 76 (99%) patients. A second bolus of dexmedetomidine was required in 28 (36%) patients, and 22 (29%) patients required additional medications (midazolam, fentanyl, or ketamine) for adequate sedation. A 25% decrease in blood pressure (BP) was observed in 10.5%, a transient increase in BP in 3.9%, and a heart rate <60 min(-1) in 7.9% of cases. These side effects resolved spontaneously. There were no apneas or respiratory depression. Vital sign changes, recovery time, and discharge time were not significantly different in subgroups of patients receiving one or two boluses of dexmedetomidine with or without additional medications. Transient hypertension was more common in patients receiving two boluses of dexmedetomidine (P = 0.048).

CONCLUSIONS

High-dose dexmedetomidine can be successfully used for pediatric MRI sedation, but a significant number of children require additional medications for optimal control. Hemodynamic side effects resolved spontaneously. High-dose dexmedetomidine did not result in respiratory depression.

Professional skills and competence for safe and effective procedural sedation in children: recommendations based on a systematic review of the literature

Objectives. To investigate which skills and competence are imperative to assure optimal effectiveness and safety of procedural sedation (PS) in children and to analyze the underlying levels of evidence. Study Design and methods. Systematic review of literature published between 1993 and March 2009. Selected papers were classified according to their methodological quality and summarized in evidence-based conclusions. Next, conclusions were used to formulate recommendations. Results. Although the safety profiles vary among PS drugs, the possibility of potentially serious adverse events and the predictability of depth and duration of sedation define the imperative skills and competence necessary for a timely recognition and appropriate management. The level of effectiveness is mainly determined by the ability to apply titratable PS, including deep sedation using short-acting anesthetics for invasive procedures and nitrous oxide for minor painful procedures, and the implementation of non-pharmacological techniques. Conclusions. PS related safety and effectiveness are determined by the circumstances and professional skills rather than by specific pharmacologic characteristics. Evidence based recommendations regarding necessary skills and competence should be used to set up training programs and to define which professionals can and cannot be credentialed for PS in children.

Vocal cord function and bispectral index in pediatric bronchoscopy patients emerging from propofol anesthesia

OBJECTIVE

In children undergoing bronchoscopy for evaluation of stridor or respiratory symptoms, movement of the vocal cords is routinely assessed at the conclusion of flexible bronchoscopy with children still anesthetized. The effect of anesthesia on vocal cord function is not well described. This study aimed to characterize the relationship between depth of propofol anesthesia, as measured by Bispectral Index (BIS), and vocal cord movement in pediatric patients.

METHODS

Children between 6 months and 12 years of age presenting for diagnostic flexible bronchoscopy were enrolled in this prospective observational study. Anesthesia was maintained with a propofol infusion which was discontinued upon completion of the lower airway evaluation. An independent observer recorded the BIS score every 15 sec from discontinuation of propofol whereas the pulmonologist continued to observe vocal cord motion. BIS scores were also recorded for each observed clinical endpoint (paradoxical and normal vocal cord movement, complete vocal cord closure, and volitional movement).

RESULTS

Data were analyzed for 47 subjects. The BIS values increased significantly from the conclusion of the lower airway evaluation with return of normal vocal cord movement, complete vocal cord closure, and volitional movement (P < 0.0005). BIS readings were higher for patients younger than 2 years. Paradoxical vocal cord movement was documented in 10.6% of subjects, but resolved in all subjects.

CONCLUSIONS

Our findings suggest that return of vocal cord function during emergence from propofol anesthesia is related to decreasing anesthetic depth with complete vocal cord closure occurring at BIS values near those associated with volitional movement.

Titrated propofol induction vs. continuous infusion in children undergoing magnetic resonance imaging

BACKGROUND

Propofol is the popular intravenous (i.v.) anaesthetic for paediatric sedation because of its rapid onset and recovery. We compared the efficacy and safety of a single dose and conventional infusion of propofol for sedation in children who underwent magnetic resonance imaging (MRI).

METHODS

This was a double-blind, randomized-controlled study. One hundred and sixty children were assigned to group I (single dose) or II (infusion). Sedation was induced with i.v. propofol 2 mg/kg, and supplemental doses of propofol 0.5 mg/kg were administered until adequate sedation was achieved. After the induction of sedation, we treated patients with a continuous infusion of normal saline at a rate of 0.3 ml/kg/h in group I and the same volume of propofol in group II. In case of inadequate sedation, additional propofol 0.5 mg/kg was administered and the infusion rate was increased by 0.05 ml/kg/h. Induction time, sedation time, recovery time, additional sedation and adverse events were recorded.

RESULTS

Recovery time was significantly shorter in group I compared with group II [0 (0-3) vs. 1 (0-3), respectively, P<0.001]. Group I (single dose) had significantly more patients with recovery time 0 compared with group II (infusion) (65/80 vs. 36/80, respectively, P<0.001). Induction and sedation times were not significantly different between groups. There was no significant difference in the frequency of additional sedation and adverse events between groups.

CONCLUSION

A single dose of propofol without a continuous infusion can provide appropriate sedation in children undergoing MRI for <30 min.

Attenuation of cerebral venous contrast in susceptibility-weighted imaging of spontaneously breathing pediatric patients sedated with propofol

BACKGROUND AND PURPOSE

SWI is known for its detailed visualization of the cerebral venous system and seems to be a promising tool for early detection of cerebrovascular pathologies in children, who are frequently sedated for MR imaging. Because sedation influences cerebral hemodynamics, we hypothesized that it would affect cerebral venous contrast in SWI.

MATERIALS AND METHODS

SWI (125 examinations) of 26 patients (age, 2-16 years) was reviewed in this study. Images were acquired of patients sedated with propofol. Reviewers classified the images by weak or strong venous contrast. Physiologic data, such as etCO(2), BP, age, and CBF by arterial spin-labeling, were monitored and collected during MR imaging. A generalized estimating equation approach was used to model associations of these parameters with venous contrast.

RESULTS

EtCO(2) and CBF were found to correlate with venous contrast, suggesting that patients with high etCO(2) and CBF have weak contrast and patients with low etCO(2) and CBF have strong contrast. BP was also found to correlate with the venous contrast of SWI, suggesting that patients with high BP have strong venous contrast. No significant correlations were found for any other physiologic parameters.

CONCLUSIONS

We found that the venous contrast in SWI is affected by propofol sedation in spontaneously breathing patients. We also found that low etCO(2), low CBF, and high BP are associated with strong venous contrast. Reviewing SWI data in light of physiologic measures may therefore help prevent potential misinterpretations of weak venous contrast in SWI examinations under propofol sedation.

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.

Functional magnetic resonance imaging (fMRI) in children sedated with propofol or midazolam

Magnetic resonance imaging (MRI) requires patient immobility and children generally need to be sedated. The ideal sedative agent for functional MRI (fMRI) should only minimally hamper the neurophysiologic effect of the administered sensorial stimulation. This study compares the effect of propofol and midazolam on the fMRI auditory activation pattern in children. Fourteen children in the 3 to 7 year age group without neurologic or auditory deficits were randomly assigned to receive propofol or midazolam for sedation during auditory fMRI. Two patients in the midazolam group were excluded due to positive baseline MRIs. The children were stimulated using a passive listening task. The fMRI signal was modeled using various functions (hemodynamic response function, temporal derivative, and dispersion derivative) to check for the differing temporal characteristics of the signal between the groups. Patients in the propofol group showed activation only in the primary auditory cortex and exhibited a pattern more similar to that of nonsedated adults. Patients in the midazolam group exhibited a more complex pattern, presenting activation areas other than the primary auditory cortex; a delay in the functional response and higher duration variability were also observed. Our sample sizes are too small to derive a conclusive inference. Our preliminary study encourages the hypothesis that propofol is preferable to midazolam to maintain sedation in 3 to 7-year-old children during auditory fMRI because it facilitates the elicitation of a more focused auditory cortical activation pattern with less temporal and spatial dispersion.

A randomized trial comparing sevoflurane and propofol in children undergoing MRI scans

OBJECTIVES

We compared three primary outcomes of pausing the magnetic resonance imaging (MRI) scan, emergence quality and respiratory complications.

AIM

To measure and compare the quality between sevoflurane and propofol in children undergoing MRI scans.

BACKGROUND

No randomized controlled trial exists comparing the quality between sevoflurane and propofol for MRI.

METHODS/MATERIALS

Two hundred unpremedicated children (18 months to 7 years) scheduled for brain MRI scans were recruited. After induction with sevoflurane, children were randomized to receive sevoflurane [general anesthesia with sevoflurane (GAS)] via laryngeal mask airway (LMA) or propofol [general anesthesia with propofol (GAP)] bolus and infusion for their scan. The three primary outcomes of pausing the MRI scan (P), agitation (A), and respiratory complications (R) were compared. Timeliness of care was also measured.

RESULTS

No MRI scan pauses were found in 92% and 80% in the GAS and GAP groups. The median and interquartile A scores were 3 (0, 7) in GAS and 0 (0, 4) in GAP groups respectively. There was no difference in respiratory complications between GAS and GAP (P = 0.62). The median and interquartile postanesthesia care unit (PACU) times were 25 (18, 34) for GAS and 31 (25, 44) for GAP (P = 0.0001). The median and interquartile total times were 78 (69, 90) for GAS and 88 (78, 100) for GAP (P = 0.0002).

CONCLUSION

Our study compared the three primary outcomes of pausing, agitation, and respiratory complications between the two groups, and we found no difference in respiratory complications. However, the GAP group had more pausing and less agitation than the GAS group.

Sedation for emergent diagnostic imaging studies in pediatric patients

PURPOSE OF REVIEW

To review and summarize current literature regarding sedation for imaging studies in pediatric patients in the Emergency Department and acute care setting.

RECENT FINDINGS

Multiple guidelines about preparation, monitoring, and appropriate training of personnel administering pediatric sedation have been published. Recommendations for fasting prior to sedation remain in flux. Agents such as chloral hydrate, barbiturates, and benzodiazepines that have been used for pediatric sedation for many years continue to be studied. These agents are compared with newer agents such as etomidate, propofol, and dexmedetomidine.

SUMMARY

Although avoiding sedation for diagnostic imaging studies is optimal, there are multiple agents with reasonable safety profiles that can be utilized by personnel trained in pediatric airway management in order to obtain adequate emergent imaging studies.

Propofol vs pentobarbital for sedation of children undergoing magnetic resonance imaging: results from the Pediatric Sedation Research Consortium

BACKGROUND

Pentobarbital and propofol are commonly used to sedate children undergoing magnetic resonance imaging (MRI). The Pediatric Sedation Research Consortium (PSRC) was created in 2003 to improve pediatric sedation process and outcomes.

OBJECTIVE

To use PSRC records to compare the effectiveness, efficiency and adverse events of propofol vs pentobarbital for sedation of children undergoing MRI.

METHODS

Pediatric Sedation Research Consortium records of children aged 6 months to 6 years who were primarily sedated with either i.v. pentobarbital or propofol were included. Participating PSRC investigators obtained institutional review board approval before data collection.

RESULTS

Of 11 846 sedations for MRI, 7079 met inclusion criteria (propofol: n = 5072; pentobarbital: n = 2007). Demographic details were similar between the two groups. Ideal sedation was produced in 96.45% of the pentobarbital group and in 96.8% of the propofol group (P = 0.478), but pentobarbital was more likely to result in poor sedation cancelling the procedure (OR 5.88; CI 2.24, 15.40). Propofol resulted in physiologic changes more frequently than did pentobarbital (OR 5.69; CI 1.35, 23.97). Pentobarbital was associated with prolonged recovery (OR 16.82; CI 4.98, 56.8), unplanned admission (OR 5.60; CI 1.02, 30.82), vomiting (OR 36.76; CI 4.84, 279.2) and allergic complication (OR 9.15; CI 1.02, 82.34). The incidence of airway complications was not significantly different between the two. The median recovery time for patients receiving propofol was 30 min, whereas for pentobarbital it was 75 min (P < 0.001).

CONCLUSION

Among institutions contributing data to the PSRC, it is found that propofol provides more efficient and effective sedation than pentobarbital for children undergoing MRI. Although apnea occurred with a greater frequency in patients who received propofol, the rate of apnea and airway complications for propofol was not statistically different from that seen in patients who received pentobarbital.

The incidence and nature of adverse events during pediatric sedation/anesthesia with propofol for procedures outside the operating room: a report from the Pediatric Sedation Research Consortium

OBJECTIVE

We used a large database of prospectively collected data on pediatric sedation/anesthesia outside the operating room provided by a wide range of pediatric specialists to delineate the nature and frequency of adverse events associated with propofol-based sedation/anesthesia care.

PATIENTS AND METHODS

Data were collected by the Pediatric Sedation Research Consortium, a collaborative group of institutions dedicated to improving sedation/anesthesia care for children internationally. Members prospectively enrolled consecutive patients receiving sedation or sedation/anesthesia for procedures. The primary inclusion criterion was the need for some form of sedation/anesthesia to perform a diagnostic or therapeutic procedure outside the operating room. There were no exclusion criteria. Data on demographics, primary illness, coexisting illness, procedure performed, medications used, procedure and recovery times, medication doses outcomes of anesthesia, airway interventions and adverse events were collected and reported using web-based data collection tool. For this study, we evaluated all instances where propofol was used as the primary drug in the sedation/anesthesia technique.

RESULTS

Thirty-seven locations submitted data on 49,836 propofol sedation/anesthesia encounters during the study period from July 1, 2004 until September 1, 2007. There were no deaths. Cardiopulmonary resuscitation was required twice. Aspiration during sedation/anesthesia occurred four times. Less serious events were more common with O(2) desaturation below 90% for more than 30 s, occurring 154 times per 10,000 sedation/anesthesia administrations. Central apnea or airway obstruction occurred 575 times per 10,000 sedation/anesthesia administrations. Stridor, laryngospasm, excessive secretions, and vomiting had frequencies of 50, 96, 341, and 49 per 10,000 encounters, respectively. Unexpected admissions (increases in levels of care required) occurred at a rate of 7.1 per 10,000 encounters. In an unadjusted analysis, the rate of pulmonary adverse events was not different for anesthesiologists versus other providers.

CONCLUSIONS

We report the largest series of pediatric propofol sedation/anesthesia for procedures outside the operating room. The data indicate that propofol sedation/anesthesia is unlikely to yield serious adverse outcomes in a collection of institutions with highly motivated and organized sedation/anesthesia services. However, the safety of this practice is dependent on a system's ability to manage less serious events. We propose that our data suggest variables for training and credentialing providers of propofol sedation/anesthesia and the system characteristics that promote safe use of this drug.