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

Intravenous esketamine as an adjuvant for sedation/analgesia outside the operating room: a systematic review and meta-analysis

Background

This study was conducted to evaluate the safety and efficacy of intravenous esketamine as an adjuvant for sedation or analgesia outside the operating room in adults and children.

Method

PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and Scopus were searched for potential randomized controlled studies randomized controlled trials comparing drug combinations of esketamine to any other single or combination drug regimens for sedation or analgesia outside the operating room.

Results

Twenty-five studies with a total of 3,455 participants were included in this review. The pooled results of adults showed that compared with drug regimens of the control group, intravenous esketamine combinations were significantly associated with decreased risk of oxygen desaturation (RR = 0.49, 95% CI = [0.34, 0.70]); hypotension (RR = 0.38, 95% CI = [0.31, 0.46]); bradycardia (RR = 0.23, 95% CI = [0.12, 0.43]); injection pain (RR = 0.37, 95% CI = [0.25, 0.53]); body movement (RR = 0.60, 95% CI = [0.41, 0.88]); and propofol consumption (SMD = -1.38, 95% CI = [-2.64, -0.11]), but an increased risk of psychiatric symptoms (RR = 3.10, 95% CI = [2.11, 4.54]) (RR = relative risk; CI = confidence intervals; SMD = standardized mean difference). Subgroup analysis showed that only the combination of esketamine and propofol significantly reduced the above incidence of respiratory and cardiovascular adverse events in adults. In addition, the pooled results of children showed that compared with drug regimens of the control group, esketamine and propofol co-administration significantly reduced the risk of hypotension (RR = 0.59, 95% CI = [0.37, 0.95]) but increased the risk of visual disturbance (RR = 6.62, 95% CI = [2.18, 20.13]) and dizziness (RR = 1.99, 95% CI = [1.17, 3,37]). Subgroup analysis indicated that esketamine>0.5 mg/kg significantly reduced the incidence of hypotension, but increased the risk of dizziness in children.

Conclusion

Intravenous use of esketamine, particularly in combination with propofol, may improve the safety and efficacy of sedation and analgesia outside the operating room, although the potential for psychiatric side effects warrants attention. Future research is recommended to investigate the role of esketamine with agents other than propofol.

Combined sedation in pediatric magnetic resonance imaging: determination of median effective dose of intranasal dexmedetomidine combined with oral midazolam

BACKGROUND

The exact median effective dose (ED50) of intranasal dexmedetomidine combined with oral midazolam sedation for magnetic resonance imaging (MRI) examination in children remains unknow and the aim of this study was to determine the ED50 of their combination.

METHODS

This is a prospective dose-finding study. A total of 53 children aged from 2 months to 6 years scheduled for MRI examination from February 2023 to April 2023 were randomly divided into group D (to determine the ED50 of intranasal dexmedetomidine) and group M (to determine the ED50 of oral midazolam). The dosage of dexmedetomidine and midazolam was adjusted according to the modified Dixon's up-and-down method, and the ED50 was calculated with a probit regression approach.

RESULTS

The ED50 of intranasal dexmedetomidine when combined with 0.5 mg∙kg- 1 oral midazolam was 0.39 µg∙kg- 1 [95% confidence interval (CI) 0.30 to 0.46 µg∙kg- 1] while the ED50 of oral midazolam was 0.17 mg∙kg- 1 (95% CI 0.01 to 0.29 mg∙kg- 1) when combined with 1 µg∙kg- 1 intranasal dexmedetomidine. The sedation onset time of children with successful sedation in group D was longer than in group M (30.0[25.0, 38.0]vs 19.5[15.0, 35.0] min, P < 0.05). No other adverse effects were observed in the day and 24 h after medication except one dysphoria.

CONCLUSION

This drug combination sedation regimen appears suitable for children scheduled for MRI examinations, offering a more precise approach to guide the clinical use of sedative drugs in children.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, identifier: ChiCTR2300068611(24/02/2023).

Safety and quality in paediatric procedural sedation: what really matters?

PURPOSE OF REVIEW

This review gives an overview of the safety aspects for paediatric procedural sedation and a discussion of possibilities for optimizing structure, processes and outcomes.

RECENT FINDINGS

Procedural sedation in paediatric patients is performed by providers of different specialties and compliance with safety standards is a basic requirement regardless of provider specialty. This includes preprocedural evaluation, monitoring, equipment and profound expertise of sedation teams. The choice of sedative medications and the possibility of incorporating nonpharmacological methods play an important role for optimal outcome. In addition, an ideal outcome from the patient's perspective includes optimized processes and clear and empathetic communication.

SUMMARY

Institutions providing paediatric procedural sedation must ensure the comprehensive training of sedations teams. Furthermore, institutional standards for equipment, processes and optimal choice of medication depending on performed procedure and comorbidities of the patient must be established. At the same time, organizational and communication aspects should be considered.

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).

Dexmedetomidine as a sole sedative for procedural sedation in preterm and neonate infants: A retrospective analysis

BACKGROUND

Many different sedation concepts for magnetic resonance imaging have been described for prematurely and term-born infants, ranging from "no sedation" to general anesthesia. Dexmedetomidine is an alpha-2 receptor agonist that is frequently used to sedate older children, because the anesthesiologist can easily adjust sedation depth, the patient maintains spontaneous breathing, and awakens rapidly afterwards.

AIMS

The present study evaluates whether dexmedetomidine could safely be used as the sole sedative for prematurely and term-born infants less than 60 weeks postconceptional age undergoing diagnostic procedures.

METHODS

We performed a retrospective monocentric analysis of n = 39 prematurely and term-born infants (<60 weeks postconceptional age or a body weight <5 kg) who were sedated with dexmedetomidine for an MRI at a German university hospital from August 2016 to November 2018.

RESULTS

Successful imaging was achieved in all cases. The median initial bolus of dexmedetomidine administered over 10 min was 1.39 μg kg^-1 body weight (range 0.34-3.64 μg kg^-1 ), followed with a continuous infusion at a median rate of 1.00 μg kg^-1  h^-1 (range 0.5-3.5 μg kg^-1  h^-1 ); however, 3 patients (7%) needed some additional sedation (ketamine or propofol). All patients, including 10 infants who had previously required respiratory support, underwent the procedure without any relevant desaturation or apnea. Bradycardia was observed in up to 15 out of 39 cases (38.5%), but only four (10.3% in total and 26.7% of bradycardia) required atropine.

CONCLUSIONS

These results indicate that dexmedetomidine can be safely used for procedural sedation in the high-risk cohort of prematurely and term-born infants less than 60 weeks postconceptional age. Apnea during procedural sedation and subsequent stay in the recovery room is avoided, but bradycardia remains a relevant risk that may require treatment.

Dexmedetomidine reduces propofol-induced hippocampal neuron injury by modulating the miR-377-5p/Arc pathway

BACKGROUND

Propofol and dexmedetomidine (DEX) are widely used in general anesthesia, and exert toxic and protective effects on hippocampal neurons, respectively. The study sought to investigate the molecular mechanisms of DEX-mediated neuroprotection against propofol-induced hippocampal neuron injury in mouse brains.

METHODS

Hippocampal neurons of mice and HT22 cells were treated with propofol, DEX, and propofol+DEX. In addition, transfection of miR-377-5p mimics or inhibitors was performed in HT22 cells. Neuronal apoptosis was evaluated by a means of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) or Hochest 33,258 staining; Arc positive expression in hippocampus tissues was detected using a microscope in immunohistochemistry assays; miRNA-377-5p expression was quantified by RT-qPCR; the protein levels of Arc, DNMT3A, and DNMT3B were determined using western blot; Cell Counting Kit-8 (CCK-8) assay was used to detect the viability and apoptotic rate of the neurons; methylation analysis in the miR-377-5p promoter was performed through methylated DNA immunoprecipitation (MeDIP) assay; dual luciferase reporter assay was performed to confirm whether Arc was under targeted regulation of miR-377-5p.

RESULTS

In the current study, both in vitro and in vivo, propofol treatment induced hippocampal neuron apoptosis and suppressed cell viability. DNMT3A and DNMT3B expression levels were decreased following propofol treatment, resulting in lowered methylation in the miR-377-5p promoter region and then enhanced expression of miR-377-5p, leading to a decrease in the expression of downstream Arc. Conversely, the expression levels of DNMT3A and DNMT3B were increased following DEX treatment, thus methylation in miR-377-5p promoter region was improved, and miR-377-5p expression was decreased, leading to an increase in the expression of downstream Arc. Eventually, DEX pretreatment protected hippocampal neurons against propofol-induced neurotoxicity by recovering the expression levels of DNMT3A, miR-377-5p, and Arc to the normal levels. Additionally, DNMT3A knockdown improved miR-377-5p expression but reduced Arc expression, and DNMT3A overexpression exerted the opposite effects. Dual luciferase reporter assay revealed a binding target between miR-377-5p and Arc 3'UTR. The neuroprotective effect of DEX against propofol-induced neuronal apoptosis was diminished after Arc knockdown. Silencing Arc independently triggered the apoptosis of HT22 cells, which was alleviated through transfection of miR-377-5p inhibitors.

CONCLUSIONS

DEX reduced propofol-induced hippocampal neuron injury via the miR-377-5p/Arc signaling pathway.

Propofol context-sensitive decrement times in children

Plasma drug concentration is the variable linking dose to effect. The decrement time required for plasma concentration of anesthetic agents to decrease by 50% (context-sensitive half-time) correlates with the time taken to regain consciousness. However, the decrement time to consciousness may not be 50%. An effect compartment concentration is associated more closely with return of consciousness than plasma concentration. An alternative decrement time, the time required for propofol to decrease to a predetermined effect compartment concentration associated with movement (eg, 2 µg.ml^-1 ), was used to simulate time for the concentration to decrease from steady state at a typical targeted effect compartment concentration 3.5 µg.ml^-1 in children. These times were short and reflected a decrement time to consciousness (CST_AWAKE ) increase that was small with longer infusion time. CST_AWAKE ranged from 7.5 min in 1-year-old infant given propofol for 15 min to 13.5 min in a 15-year-old adolescent given a 2-hour infusion. Changes in decrement time with age reflect maturation of drug clearance. Neonates had prolonged increment times, 10 min after 15 min infusion and 18 min after 120 min infusion using a target concentration of 3.5 µg.ml^-1 . Decrement times to a targeted arousal concentration are context-sensitive. Use of a higher target concentration of 6 µg.ml^-1 doubled decrement times. Decrement times are associated with variability: delayed recovery beyond these simulated times is likely more attributable to the use of adjuvant drugs or the child's clinical status. An understanding of propofol decrement times can be used to guide recovery after anesthesia.

Using intranasal dexmedetomidine with buccal midazolam for magnetic resonance imaging sedation in children: A single-arm prospective interventional study

OBJECTIVE

Although numerous intravenous sedative regimens have been documented, the ideal non-parenteral sedation regimen for magnetic resonance imaging (MRI) has not been determined. This prospective, interventional study aimed to investigate the efficacy and safety of buccal midazolam in combination with intranasal dexmedetomidine in children undergoing MRI.

METHODS

Children between 1 month and 10 years old requiring sedation for MRI examination were recruited to receive buccal midazolam 0.2 mg⋅kg^-1 with intranasal dexmedetomidine 3 μg⋅kg^-1. The primary outcome was successful sedation following the administration of the initial sedation regimens and the completion of the MRI examination.

RESULTS

Sedation with dexmedetomidine-midazolam was administered to 530 children. The successful sedation rate was 95.3% (95% confidence interval: 93.5-97.1%) with the initial sedation regimens and 97.7% (95% confidence interval: 96.5-99%) with a rescue dose of 2 μg⋅kg^-1 intranasal dexmedetomidine. The median sedation onset time was 10 min, and a significant rising trend was observed in the onset time concerning age (R = 0.2491, P < 0.001). The wake-up and discharge times significantly correlated with the duration of the procedure (R = 0.323, P < 0.001 vs. R = 0.325, P < 0.001). No oxygen deficiency nor medication intervention due to cardiovascular instability was observed in any of the patients. History of a prior failed sedation was considered a statistically significant risk factor for failed sedation in the multivariate logistic regression model [odds ratio = 4.71 (95% confidence interval: 1.24-17.9), P = 0.023].

CONCLUSION

In MRI examinations, the addition of buccal midazolam to intranasal dexmedetomidine is associated with a high success rate and a good safety profile. This non-parenteral sedation regimen can be a feasible and convenient option for short-duration MRI in children between 1 month and 10 years.

Sedation with dexmedetomidine and propofol in children with Fontan circulation undergoing cardiac catheterization: A descriptive study

Background:

A combination of dexmedetomidine and propofol is considered advantageous for maintaining spontaneous breathing with a satisfactory depth of anesthesia. However, the incidence of upper airway obstruction under sedation with dexmedetomidine and propofol in patients with Fontan circulation remains unanswered. This study aimed to evaluate upper airway patency and oxygen desaturation during sedation with dexmedetomidine and propofol for cardiac catheterization in pediatric patients with Fontan circulation.

Methods:

In this descriptive study, we reviewed medical records of patients with Fontan circulation who underwent cardiac catheterization between December 2018 and August 2020 at a single-center 200-bed academic children's hospital in Japan.

Results:

A total of 35 patients with Fontan circulation sedated with a departmental protocol of dexmedetomidine and propofol infusion for cardiac catheterization were reviewed. Overall, the incidence of airway interventions and oxygen desaturation were 31.4% and 28.6%, respectively. In children with a history of snoring and additional use of intravenous midazolam, the rates of airway interventions were 50% and 100%, respectively. In patients ≤2 years old with recent upper respiratory infection (URI) symptoms, oxygen desaturation rate was 75%.

Conclusions:

In children with Fontan circulation, the incidence rate of upper airway obstruction was high under sedation with dexmedetomidine and propofol during cardiac catheterization, which is commonly considered safe in children without Fontan circulation. A history of snoring, an additional bolus of IV midazolam, and the presence of recent URI symptoms in patients ≤2 years old are potential risks for upper airway obstruction.

Comparison of Intra and Post-operative Sedation efficacy of Dexmedetomidine-Midazolam and Dexmedetomidine-Propofol for Major Abdominal Surgery

BACKGROUND

The effectiveness and side effects of dexmedetomidine (DEX) in combination with midazolam and propofol have not been comparatively studied in a single clinical trial as sedative agents to general anesthesia before.

OBJECTIVE

The objective of this study is to compare intra and post-operative sedation between DEX-Midazolam and DEX-Propofol in patients who underwent major abdominal surgery on the duration of general anesthesia, hemodynamic and sedation effect.

METHOD

This prospective, randomized, double-blinded clinical trial included 50 patients who were 20 to 60 years of age and admitted for major abdominal surgery. The patients were randomly assigned by a computer-generated random numbers table to sedation with DEX plus midazolam (DM group) (n=25) or DEX plus propofol (DP group) (n=25). In the DM group, patients received a bolus dose of 0.1 mg/kg of midazolam and immediately initiated the intravenous (i.v.) infusion of DEX 1 µg/kg over a 10 min and 0.5 µg/kg/hr by continuous i.v. infusion within operation period. In the DP group, patients received pre-anesthetic i.v. DEX 1 µg/kg over 15 min before anesthesia induction and 0.2-1 µg/kg/hr by continuous i.v. infusion during the operative period. After preoxygenation for at least 2 min, during the surgery, patients received propofol infusion dose of 250 μg/kg/min for 15 min then a basal infusion dose of 50 μg/kg/min. The bispectral index (BIS) value, as well as mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), oxygen saturation (SaO2), percutaneous arterial oxygen saturation (SpO2) and end-tidal carbon dioxide tension (ETCO2) were recorded before anesthesia (T0), during anesthesia (at 15-min intervals throughout the surgical procedure), by a blinded observer. Evidence of apnea, hypotension, hypertension and hypoxemia were recorded during surgery.

RESULTS

The hemodynamic changes, including HR, MAP, BIS, VT, SaO2, and RR had a downward tendency with time, but no significant difference was observed between the groups (P>0.05). However, the two groups showed no significant differences in ETCO2 and SPO2 values in any of the assessed interval (P>0.05). In this study, the two groups showed no significant differences in the incidence of nausea, vomiting, coughing, apnea, hypotension, hypertension, bradycardia and hypoxemia (P>0.05). Respiratory depression and serious adverse events were not reported in either group. Extubation time after surgery was respectively 6.3 ± 1.7 and 5.8 ± 1.4 hr. in the DM and DP groups and the difference was not statistically significant (P= 0.46).

CONCLUSION

Our study showed no significant differences between the groups in hemodynamic and respiratory changes in each of the time intervals. There were also no significant differences between the two groups in the incidence of complication intra and post-operative. Further investigations are required to specify the optimum doses of using drugs which provide safety in cardiovascular and respiratory system without adverse disturbance during surgery.

Trends in Pediatric MRI sedation/anesthesia at a tertiary medical center over time

BACKGROUND

Each year, hundreds of thousands of children require sedation/anesthesia to facilitate MRI scans. Anesthetic techniques for accomplishing sedation/anesthesia vary widely between institutions and providers, with unclear implications for patient safety.

AIMS

We sought to establish trends in anesthetic practice for pediatric MRI sedation/anesthesia across a 7-year period and determine rates of adverse events, considering technique used, age, and ASA physical classification status (ASA-PS).

METHODS

Using established data resources, we analyzed 24 052 anesthetics performed by anesthesiologists for MRI scans between 5/1/2013 and 12/31/2019 on patients less than 18 years old, focusing on medications used, trends of use, and associated adverse events. Adverse events (hypoxia, hypotension, bradycardia) were defined by deviation from age norms and accessed via the electronic anesthetic record database. The Cochran-Armitage test was used to assess trends over time in categorical data, and one-way ANOVA was used to analyze continuous data. Multivariable logistic regression analysis was implemented to determine the independent associations between anesthetic technique and adverse events while adjusting for age, ASA-PS, and weight.

RESULTS

The most significant trends noted were a decrease in "propofol-only" anesthetic techniques and an increase in propofol and dexmedetomidine combination techniques. Mild desaturation (80-89% SpO₂ ) occurred in 4.22% of cases with more significant hypoxia much rarer (0.44% of cases having desaturation <70% SpO₂ ). Bradycardia occurred in 2.39% of cases and hypotension in 1.75% of cases. Major adverse events were rare.

CONCLUSIONS

We provide the largest report of the nature of MRI sedation/anesthesia as practiced by anesthesiologists in a large children's hospital. We demonstrate that, even in a large system, anesthetic techniques are pliable and shift significantly over time. Our data also support a high level of safety within our system, despite a case mix likely higher in risk than those in most of the previously published studies.

Outcomes of deep sedation for catheter ablation of paroxysmal supraventricular tachycardia, with adaptive servo ventilation

BACKGROUND

Catheter ablation for paroxysmal supraventricular tachycardia (PSVT) is an established treatment, but the effect of deep sedation on PSVT inducibility remains unclear.

AIM

We sought to examine PSVT inducibility and outcomes of catheter ablation under deep sedation using adaptive servo ventilation (ASV).

METHODS

We retrospectively evaluated consecutive patients who underwent catheter ablation for PSVT under deep sedation (Propofol + Dexmedetomidine) with use of ASV. Anesthetic depth was controlled with BIS™ monitoring, and phenylephrine was administered to prevent anesthesia-induced hypotension. PSVT induction was attempted in all patients using extrastimuli at baseline, and after isoproterenol (ISP) infusion when necessary.

RESULTS

PSVT was successfully induced in 145 of 147 patients, although ISP infusion was required in the majority (89%). The PSVT was atrioventricular nodal reentrant tachycardia (AVNRT) in 77 (53%), atrioventricular reciprocating tachycardia (AVRT) in 51 (35%), and atrial tachycardia (AT) in 17 (12%). A higher ISP dose was required for AT compared to other PSVT (AVNRT: 0.06 (IQR 0.03-0.06) vs AVRT: 0.03 (0.02-0.06) vs AT: 0.06 (0.03-0.12) mg/h, P = .013). More than half (51%) of the patients developed hypotension requiring phenylephrine; these patients were older. Acute success was obtained in 99% (patients with AVNRT had endpoints with single echo on ISP in 46%). Long-term success rate was 136 of 144 (94%) (AVNRT 96%, AVRT 92%, and AT 93%). There were no complications related to deep sedation.

CONCLUSIONS

Deep sedation with use of ASV is a feasible anesthesia strategy for catheter ablation of PSVT with good long-term outcome. PSVT remains inducible if ISP is used.

Comparison of sedation between dexmedetomidine and propofol during transesophageal echocardiography: A randomized controlled trial

Background:

This study aimed to compare sedation characteristics of dexmedetomidine (Dex) and propofol during transesophageal echocardiography (TEE) in cardiac patients.

Methods:

This clinical trial was conducted on 65 cardiac patients, who underwent TEE in a referral heart hospital. The patients were randomly divided into two groups: Dex (n = 34) and propofol (n = 31). The depth of sedation in the patients was assessed at 5-min intervals until the end of the TEE examination. The patient, physicians’ satisfaction was recorded. Furthermore, blood pressure, heart and respiratory rates, peripheral oxygen saturation, and the bispectral index (BIS) of the patients were measured. The occurrence of apnea, hypotension or bradycardia was documented.

Results:

Demographic variables were similar in both groups. Time from the beginning of sedation to the start of TEE was significantly longer in the Dex group (P = 0.01). Duration of the TEE examination was not different between the two groups. Interestingly, the recovery time was shorter in the Dex group than in the propofol group. There were no significant differences regarding patient and physician satisfaction with sedation quality. Hemodynamic profile was mainly similar in both groups. There was a significantly lower BIS level in the Dex group. There was no significant difference in the incidence of apnea or hypotension between the groups.

Conclusions:

Time from the beginning of sedation with Dex was longer than that with propofol. However, Dex was able to provide satisfactory sedation levels, hemodynamic stability, short recovery time, and acceptable patient and practitioner satisfaction during TEE in our cardiac patients.

Efficacy and safety of intravenous thiamylal in pediatric procedural sedation for magnetic resonance imaging

OBJECTIVE

To evaluate the efficacy and safety of intravenous (i.v.) thiamylal in pediatric magnetic resonance imaging (MRI) sedation.

METHODS

Infants and children from 1 month up to 8 years of age who underwent MRI in our hospital between April 2017 and March 2019 were included in this prospective observational study. Initial dose of 2 mg/kg thiamylal was given intravenously; however, additional doses were administered as needed. MRI was performed after adequate sedation was achieved. The primary endpoint was the success rate of MRI, while secondary endpoints were adverse events related to sedation, time to sedate, recovery time, and the dose of thiamylal.

RESULTS

A total of 118 patients were included in the analysis with median age and weight of 31.5 months (14.0-56.8 months) and 12.6 kg (9.5-15.7 kg), respectively. The success rate of MRI was 96.6% (114/118), and the median dose of thiamylal per body weight was 3.6 (2.8-4.0) mg/kg. The median time from the first dose of thiamylal to MRI was 7 min (4-10 min) and that from the end of MRI scanning to the confirmation of emergence was 8 min (5-25 min). Adverse events encountered included respiratory arrests (n = 3) and reduction in oxygen saturation (SpO₂; n = 9). There were no significant differences in the age, dose of thiamylal, sex, body weight, the American Society of Anesthesiologists physical status, and neurological abnormalities between the groups with and without respiratory complications.

CONCLUSION

This study demonstrated an adequate efficacy and safety of i.v. thiamylal, with rapid sedation and patient recovery.

Pediatric Anesthesia Outside the Operating Room: Case Management

Anesthesiology teams care for children in diverse locations, including diagnostic and interventional radiology, gastroenterology and pulmonary endoscopy suites, radiation oncology units, and cardiac catheterization laboratories. To provide safe, high-quality care, anesthesiologists working in these environments must understand the unique environmental and perioperative considerations and risks involved with each remote location and patient population. Once these variables are addressed, anesthesia and procedural teams can coordinate to ensure that patients and families receive the same high-quality care that they have come to expect in the operating room. This article also describes some of the considerations for anesthetic care in outfield locations.

[Sedative effect of intranasal midazolam in neonates undergoing magnetic resonance imaging: a prospective single-blind randomized controlled study]

OBJECTIVE

To compare intranasal midazolam and intramuscular phenobarbital sodium for their sedative effect in neonates undergoing magnetic resonance imaging (MRI).

METHODS

A total of 70 neonates who underwent cranial MRI from September 2017 to March 2019 were randomized into an observation group and a control group, with 35 cases in each group. The observation group received intranasal drops of midazolam (0.3 mg/kg), and the control group received intramuscular injection of phenobarbital sodium (10 mg/kg). The sedation status of the neonates was evaluated using the Ramsay Sedation Scale. Meanwhile, the two groups were compared for the success rate of MRI procedure and incidence of adverse reactions.

RESULTS

In the observation group, the sedation score was the highest at 20 minutes post administration, then was gradually decreasing, and decreased to the lowest level at 70 minutes post administration. In the control group, the sedation score was the lowest at 10 minutes post administration, then was gradually increasing, and increased to the highest level at 40 minutes and 50 minutes post administration, followed by a gradual decrease. Comparison of the sedation score at each time period suggested that the sedation score was significantly higher in the observation group than in the control group within 40 minutes post administration (P<0.05), while there were no significant differences between the two groups in the sedation score after 40 minutes post administration (P>0.05). The success rate of MRI procedure was significantly higher in the observation group than in the control group (89% vs 69%, P<0.05). There was no significant difference between the two groups in the incidence of adverse reactions (P>0.05).

CONCLUSIONS

Intranasal midazolam is superior to intramuscular phenobarbital sodium in the sedative effect in neonates undergoing MRI, with the benefits of being fast, convenient, safe, and effective.

Propofol use in newborns and children: is it safe? A systematic review

OBJECTIVES

To determine the main indications and assess the most common adverse events with the administration of hypnotic propofol in most pediatric clinical scenarios.

SOURCES

A systematic review of PubMed, SciELO, Cochrane, and EMBASE was performed, using filters such as a maximum of five years post-publication, and/or references or articles of importance, with emphasis on clinical trials using propofol. All articles of major relevance were blind-reviewed by both authors according to the PRISMA statement, looking for possible bias and limitations or the quality of the articles.

SUMMARY OF THE FINDINGS

Through the search criterion applied, 417 articles were found, and their abstracts evaluated. A total of 69 papers were thoroughly studied. Articles about propofol use in children are increasing, including in neonates, with the majority being cohort studies and clinical trials in two main scenarios: upper digestive endoscopy and magnetic resonance imaging. A huge list of adverse events has been published, but most articles considered them of low risk.

CONCLUSIONS

Propofol is a hypnotic drug with a safe profile of efficacy and adverse events. Indeed, when administered by non-anesthesiologists, quick access to emergency care must be provided, especially in airway events. The use of propofol in other scenarios must be better studied, aiming to reduce the limitations of its administration by general pediatricians.

Specific absorption rate implications of within-scan patient head motion for ultra-high field MRI

PURPOSE

This study investigates the implications of all degrees of freedom of within-scan patient head motion on patient safety.

METHODS

Electromagnetic simulations were performed by displacing and/or rotating a virtual body model inside an 8-channel transmit array to simulate 6 degrees of freedom of motion. Rotations of up to 20° and displacements of up to 20 mm including off-axis axial/coronal translations were investigated, yielding 104 head positions. Quadrature excitation, RF shimming, and multi-spoke parallel-transmit excitation pulses were designed for axial slice-selection at 7T, for seven slices across the head. Variation of whole-head specific absorption rate (SAR) and 10-g averaged local SAR of the designed pulses, as well as the change in the maximum eigenvalue (worst-case pulse) were investigated by comparing off-center positions to the central position.

RESULTS

In their respective worst-cases, patient motion increased the eigenvalue-based local SAR by 42%, whole-head SAR by 60%, and the 10-g averaged local SAR by 210%. Local SAR was observed to be more sensitive to displacements along right-left and anterior-posterior directions than displacement in the superior-inferior direction and rotation.

CONCLUSION

This is the first study to investigate the effect of all 6 degrees of freedom of motion on safety of practical pulses. Although the results agree with the literature for overlapping cases, the results demonstrate higher increases (up to 3.1-fold) in local SAR for off-axis displacement in the axial plane, which had received less attention in the literature. This increase in local SAR could potentially affect the local SAR compliance of subjects, unless realistic within-scan patient motion is taken into account during pulse design.

Procedural Sedation Outside the Operating Room and Potential Neurotoxicity: Analysis of an At-Risk Pediatric Population

OBJECTIVES

To determine the characteristics of children who met the risk criteria for potential neurotoxicity defined by the US Food and Drug Administration (FDA; 2016 warning) in a procedural sedation (PS) service.

STUDY DESIGN

A single-center retrospective review of all infants and children aged <3 years receiving PS outside the operating room from 2014 to 2016. Demographics, duration of, and the reason for PS were analyzed.

RESULTS

A total of 2950 patients with 3653 sedation encounters were included. Median age was 19 (range, 11-26) months. Most PS (86.4%) were for magnetic resonance imaging (MRI). The median number of sedation procedures per patient was 1 (25th-75th: 1-7), and median duration of sedation was 72 minutes (25th-75th: 55-98 minutes). Forty patients (1.4%) required prolonged sedations >3 hours, in a single encounter (median, [25th-75th] of 196 minutes [185-214 minutes]), and 298 patients (10.1%) had multiple sedation exposures during the study period. Overall, 327 patients, 11.1% (95% confidence interval, 10.0%-12.3%) required repeated and/or prolonged sedation. The most common reasons for repeated or prolonged sedation were MRI of the brain and neurologic concerns.

CONCLUSIONS

Multiple and prolonged PS commonly occurs outside the operating room in this young and potentially vulnerable population. Although certain imaging cannot be avoided, other cases may have the potential to be delayed until the child is >3 years old or to have alternate imaging that may not require prolonged PS. Family and provider awareness of the FDA warnings regarding potential neurotoxicity of sedation in all settings, both inside and outside the operating room, is critical.

Practicalities of Total Intravenous Anesthesia and Target-controlled Infusion in Children

Propofol administered in conjunction with an opioid such as remifentanil is used to provide total intravenous anesthesia for children. Drugs can be given as infusion controlled manually by the physician or as automated target-controlled infusion that targets plasma or effect site. Smart pumps programmed with pharmacokinetic parameter estimates administer drugs to a preset plasma concentration. A linking rate constant parameter (keo) allows estimation of effect site concentration. There are two parameter sets, named after the first author describing them, that are commonly used in pediatric target-controlled infusion for propofol (Absalom and Kataria) and one for remifentanil (Minto). Propofol validation studies suggest that these parameter estimates are satisfactory for the majority of children. Recommended target concentrations for both propofol and remifentanil depend on the type of surgery, the degree of surgical stimulation, the use of local anesthetic blocks, and the ventilatory status of the patient. The use of processed electroencephalographic monitoring is helpful in pediatric total intravenous anesthesia and target-controlled infusion anesthesia, particularly in the presence of neuromuscular blockade.

A non-randomized controlled study of total intravenous anesthesia regimens for magnetic resonance imaging studies in children

BACKGROUND AND AIMS

We studied the efficacy and safety of different total intravenous anesthesia used for pediatric magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Children of 1-7 years age (n = 88), undergoing MRI received a loading dose of dexmedetomidine 1 μg/kg over 10 min, ketamine 1 mg/kg, and propofol 1 mg/kg in sequence. University of Michigan Sedation Scale (UMSS) of 3 was considered an acceptable level for starting the scan. Rescue ketamine 0.25-0.5 mg/kg was given if UMSS remained <3. After the loading dose of drugs, some children attained UMSS = 4 or progressive decline in heart rate, therefore, did not receive any infusion. The rest received either dexmedetomidine (0.7 μg/kg/h) (n = 35) or propofol (3 mg/kg/h) (n = 38) infusion for maintenance. Ketamine 0.25 mg/kg was used as rescue. Sedation failure was considered if either there was inability to complete the scan at the pre-set infusion rate, or there was need for >3 ketamine boluses or serious adverse events occurred. Statistical Package for Social Sciences 20 was used for analysis.

RESULTS

Initiation of scan was 100% successful with median induction time of 10 min. Maintenance of sedation was successful in 100% with dexmedetomidine and 97.4% with propofol infusion. Recovery time (25 min v/s 30 min), discharge time (35 min v/s 60 min), and total care duration (80 min v/s 105 min) were significantly less with propofol as compared to dexmedetomidine (P = 0.002, 0.000, and 0.000, respectively). There were no significant adverse events observed.

CONCLUSION

Dexmedetomidine 1μg/kg, ketamine 1 mg/kg, and propofol 1 mg/kg provide good conditions for initiation of MRI. Although dexmedetomidine at 0.7μg/kg/h and propofol at 3 mg/kg/h are safe and effective for maintenance, propofol provides faster recovery.

The utility of the pretracheal stethoscope in detecting ventilatory abnormalities during propofol sedation in children

BACKGROUND

Monitoring of ventilation with capnography or a stethoscope is recommended because the detection of ventilatory abnormalities can be significantly delayed by the use of pulse oximetry alone in patients receiving supplemental oxygen. The aim of this study was to evaluate the diagnostic performance of the pretracheal stethoscope with pulse oximetry and capnography in detecting adverse respiratory events during propofol sedation in nonintubated children. We hypothesized that use of the pretracheal stethoscope would facilitate earlier detection of adverse respiratory events.

METHODS

This was a prospective observational study of children undergoing procedural sedation at a pediatric sedation program. A pretracheal stethoscope, pulse oximetry, and nasal capnography were attached at the discretion of the sedation nurse and provider to monitor ventilation.

RESULTS

We enrolled 104 patient encounters (mean recorded time, SD 8.3 ± 5.3 minutes) from February, 2015 to March, 2017. The pretracheal stethoscope was the first monitor to detect adverse events in 64% (25/39) of patients compared to 18% (7/39) for capnography and 15% (6/39) for pulse oximetry. Auscultation performed best at detecting upper airway obstruction but capnography and pulse oximetry performed best at detecting hypoventilation. The positive predictive value for detecting a true ventilation abnormality and 95% CI of the pretracheal stethoscope, pulse oximetry, and capnography was 100% (90%-100%), 18% (10%-31%), and 27% (18%-38%), respectively. The negative predictive value and 95% CI of the pretracheal stethoscope, pulse oximetry, and capnography was 88% (82%-92%), 68% (59%-75%), and 70% (61%-78%), respectively. Limitations are short observation time, nonstandardized application of respiratory monitors, and too much focus on auscultation.

CONCLUSION

A pretracheal stethoscope in conjunction with capnography and pulse oximetry detects most sedation-related adverse events first. Auscultation performed best at detecting upper airway obstruction but capnography and pulse oximetry performed best at detecting hypoventilation.

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.

Premedication with intranasal dexmedetomidine decreases barbiturate requirement in pediatric patients sedated for magnetic resonance imaging: a retrospective study

Background

Barbiturates are commonly used in ambulatory sedation of pediatric patients. However, use of barbiturates involve risks of respiratory complications. Dexmedetomidine, a highly selective α₂-adrenoceptor agonist, is increasingly used for pediatric sedation. Premedication with intranasal (IN) dexmedetomidine offers a non-invasive and efficient possibility to sedate pediatric patients undergoing magnetic resonance imaging (MRI). Our hypothesis was that dexmedetomidine would reduce barbiturate requirements in procedural sedation.

Methods

We included 200 consecutive pediatric patients undergoing MRI, and analyzed their hospital records retrospectively. Half of the patients received 3 μg/kg of IN dexmedetomidine (DEX group) 45–60 min before MRI while the rest received only thiopental (THIO group) for procedural sedation. Sedation was maintained with further intravenous thiopental dosing as needed. Thiopental consumption, heart rate (HR) and peripheral oxygen saturation were recorded.

Results

The cumulative thiopental requirement during MRI was (median and interquartile range [IQR]) 4.4 (2.7–6.0) mg/kg/h in the DEX group and 12.4 (9.8–14.8) mg/kg/h in the THIO group (difference 7.9 mg/kg/h, 95% CI 6.8–8.8, P <  0.001). Lowest measured peripheral oxygen saturation remained slightly higher in the DEX group compared to the THIO group (median nadirs and IQR: 97 (95–97) % and 96 (94–97) %, P <  0.001). Supplemental oxygen was delivered to 33% of the patients in the THIO group compared to 2% in the DEX group (P <  0.001). The lowest measured HR (mean and SD) was lower (78 (16) bpm) in the DEX group compared to the THIO group (92 (12) bpm) (P <  0.001).

Conclusion

Premedication with IN dexmedetomidine (3 μg/kg) was associated with markedly reduced thiopental dosage needed for efficient procedural sedation for pediatric MRI.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0690-1) contains supplementary material, which is available to authorized users.

Gauging potential risk for patients in pediatric radiology by review of over 2,000 incident reports

BACKGROUND

Incident reporting can be used to inform imaging departments about adverse events and near misses.

OBJECTIVE

To study incident reports submitted during a 5-year period at a large pediatric imaging system to evaluate which imaging modalities and other factors were associated with a greater rate of filed incident reports.

MATERIALS AND METHODS

All incident reports filed between 2013 and 2017 were reviewed and categorized by modality, patient type (inpatient, outpatient or emergency center) and use of sedation/anesthesia. The number of incident reports was compared to the number of imaging studies performed during that time period to calculate an incident report rate for each factor. Statistical analysis of whether there were differences in these rates between factors was performed.

RESULTS

During the study period, there were 2,009 incident reports filed and 1,071,809 imaging studies performed for an incident report rate of 0.19%. The differences in rates by modality were statistically significant (P=0.0001). There was a greater rate of incident reports in interventional radiology (1.54%) (P=0.0001) and in magnetic resonance imaging (MRI) (0.62%) (P=0.001) as compared to other imaging modalities. There was a higher incident report rate for inpatients (0.34%) as compared to outpatient (0.1%) or emergency center (0.14%) (P=0.0001). There was a higher rate of incident reports for patients under sedation (1.27%) as compared to non-sedated (0.12%) (P=0.0001).

CONCLUSION

Using incident report rates as a proxy for potential patient harm, the areas of our pediatric radiology service that are associated with the greatest potential for issues are interventional radiology, sedated patients, and inpatients. The areas associated with the least risk are ultrasound (US) and radiography. Safety improvement efforts should be focused on the high-risk areas.

Low-dose dexmedetomidine as an adjuvant to propofol infusion for children in MRI: A double-cohort study

INTRODUCTION

Propofol is an effective sedative for magnetic resonance imaging. Nevertheless, it may cause hemodynamic and respiratory complications in a dose dependent fashion. We investigated the role of low-dose dexmedetomidine (0.5 μg/kg) as an adjuvant to propofol sedation for children undergoing magnetic resonance imaging. We hypothesized that dexmedetomidine would decrease the propofol dose required, airway complications, and hemodynamic instability.

METHODS

We performed a retrospective chart review of patients' age of 1 month to 20 years. Children were divided into 2 groups; group P received only propofol; group D + P received intravenous bolus of dexmedetomidine (0.5 μg/kg) and propofol.

RESULTS

We reviewed 172 children in P and 129 in D + P (dexmedetomidine dose, median: 0.50 μg/kg (IQR: 0.45-0.62). An additional dexmedetomidine bolus was given to 17 children for sedation lasting longer than 2 hours. Total propofol dose (μg/kg/min) was significantly higher in group P than D + P; 215.0 (182.6-253.8) vs 147.6 (127.5-180.9); Median Diff = -67.8; 95%CI = -80.6, -54.9; P < .0001. There was no difference in recovery time (minutes); P: 28 (17-39) vs D + P: 27 (18-41); Median Diff = -1; 95%CI = -6.0, 4.0; P = .694. The need for airway support was significantly greater in P compared to D + P; 15/172 vs 3/129; OR = 0.25; 95%CI = 0.07 to 0.90; P = .02 (2-sample proportions test). Mean arterial pressure was significantly lower in P compared to D + P across time over 60 minutes after induction (coef = -0.06, 95%CI = -0.11, -0.02, P = .004).

DISCUSSION & CONCLUSION

A low-dose bolus of dexmedetomidine (0.5 μg/kg) used as an adjuvant can decrease the propofol requirement for children undergoing sedation for magnetic resonance imaging. This may decrease the need for airway support and contribute to improved hemodynamic stability without prolonging recovery time.

Sedation for magnetic resonance imaging using propofol with or without ketamine at induction in pediatrics-A prospective randomized double-blinded study

INTRODUCTION

Deep sedation using propofol has become a standard technique in children. This double-blinded randomized clinical trial aims to compare the clinical effects of propofol-mono-sedation vs a combination of propofol and ketamine at induction and a reduced propofol infusion rate for maintenance in children undergoing diagnostic magnetic resonance imaging.

METHODS

Children aged from 3 months to 10 years scheduled as outpatients for elective magnetic resonance imaging with deep sedation were included. They were randomized into 2 groups, receiving either 1 mg/kg ketamine at induction, then a propofol infusion rate of 5 mg/kg/h or a propofol infusion rate of 10 mg/kg/h without prior ketamine. Time to full recovery (modified Aldrete score = 10) was the primary outcome. Further outcomes were quality of induction, immobilization during image acquisition, recovery, postoperative nausea and vomiting, emergence delirium using the Pediatric Anesthesia Emergence Delirium scale, vital signs and adverse cardiorespiratory events. All patients and parents as well as anesthetists, imaging technicians, and postsedation personnel were blinded. Data are given as median (range).

RESULTS

In total, 347 children aged 4.0 (0.25-10.9) years, weighing 15.6 (5.3-54) kg, ASA classification I, II, or III (141/188/18) were included. The ketamine-propofol group showed significantly shorter recovery times (38 (22-65) vs 54 (37-77) minutes; median difference 14 (95% CI: 8, 20) minutes; P < .001), better quality of induction, and higher blood pressure, but higher incidence of movement requiring additional sedative drugs. There were no significant differences in respiratory side effects, cardiovascular compromise, emergence delirium, or postoperative nausea and vomiting.

CONCLUSION

Both sedation concepts proved to be reliable with a low incidence of side effects. Ketamine at induction with a reduced propofol infusion rate leads to faster postanesthetic recovery.

A comparison of the use of propofol alone and propofol with midazolam for pediatric magnetic resonance imaging sedation - a retrospective cohort study

Background

Pediatric MRI sedation performed by a variety of specialists such as sedationists and anesthesiologists commonly uses propofol, which has similar effects to an ideal sedative agent for maintaining deep sedation. However, when propofol is used, adverse airway events are relatively more common than when using other sedative agents. The concomitant administration of midazolam and propofol can reduce the dose of propofol needed for adequate sedation and might also reduce the frequency of airway obstruction without affecting the patient’s recovery profile.

Methods

We reviewed the our hospital records of all pediatric MRI sedation patients aged 3 to 16 years who were sedated with either propofol alone or propofol with midazolam between December 2013 and June 2016.

Results

Eight hundred ninety-seven pediatric MRI sedation patients were included (n = 897). The frequency of airway intervention was 25/356 (7.0%) in Group P and 15/541 (2.8%) in Group PM (difference in proportions: 4.2%; 95% CI: 1.4–7.6%; p = 0.002). The mean (SD) time to awake was longer in Group PM compared to Group P [21.2 (5.6) minutes vs. 23.0 (7.1) minutes; mean difference, 1.8 min; 95% CI, 0.9–2.9; p < 0.001]. The mean (SD) time to discharge was longer in Group PM compared to Group P [34.5 (6.9) minutes vs. 38.6 (9.4) minutes; mean difference, 4.0 min; 95% CI, 3.0–5.1; p < 0.001].

Conclusions

The administration of a small dose of midazolam during pediatric MRI sedation using propofol can reduce the frequency of airway complications without prolonging the clinically significant recovery profile.