A Comparison of Dexmedetomidine-Midazolam with Propofol for Maintenance of Anesthesia in Children Undergoing Magnetic Resonance Imaging

Usefulness of deep sedation with intravenous dexmedetomidine and midazolam in cardiac catheterization procedures for pediatric patients

Background

Dexmedetomidine (DEX) is a highly selective alpha 2 receptor agonist that has the advantage of causing less respiratory depression than other sedative agents. We evaluated the add-on effects of DEX on sedation among pediatric patients who received midazolam and pentazocine during cardiac catheterization.

Methods

120 cardiac catheterization procedures in 110 patients under deep sedation at Department of Pediatrics, Kanazawa University Hospital from January 2013 to August 2018: 63 procedures without DEX (i.e., non-DEX group) and 57 procedures with DEX (i.e., DEX group). Intravenous midazolam and pentazocine were used in both groups, and DEX without an initial loading dose (0.6 μg/kg/h) was used in the DEX group. We retrospectively investigated complications during catheterization, doses of sedative agents, and changes in vital signs.

Results

Hypoxemia requiring oxygen administration during catheterization tended to be higher in the non-DEX group than in the DEX group (4.8% vs. 0%). Additional dose of midazolam was significantly lower in the DEX group (median [IQR]: 0.05 mg/kg [0-0.11]) than in the non-DEX group [0.09 mg/kg (0-0.23), p = 0.0288]. The additional dose of midazolam in the non-DEX group with hypoxemia was significantly higher than the dose used in the non-DEX group without hypoxemia. No case of bradycardia below the criteria for bradycardia occurred and no serious complications occurred in the DEX group.

Conclusion

The use of intravenous DEX in combination with midazolam and pentazocine in pediatric cardiac catheterization may reduce the need for an additional dose of midazolam and may contribute to the prevention of airway complications associated with respiratory depression caused by sedative agents.

An evaluation of dexmedetomidine in combination with midazolam in pediatric sedation: a systematic review and meta-analysis

BACKGROUND

Dexmedetomidine and midazolam are commonly used sedatives in children. We conducted a systematic review and meta-analysis to compare the safety and effectiveness of sedation provided by dexmedetomidine combined with midazolam versus other sedatives including chloral hydrate, midazolam and other sedatives in pediatric sedation.

METHODS

The Embase, Web of Science, Cochrane Library, and PubMed databases, and Clinicaltrials.gov register of controlled trials were searched from inception to June 2022. All randomized controlled trials used dexmedetomidine-midazolam in pediatric sedation were enrolled. The articles search, data extraction, and quality assessment of included studies were performed independently by two researchers. The success rate of sedation was considered as the primary outcome. The secondary outcomes included onset time of sedation, recovery time of sedation and occurrence of adverse events.

RESULTS

A total of 522 studies were screened and 6 RCTs were identified; 859 patients were analyzed. The administration of dexmedetomidine combined with midazolam was associated with a higher sedation success rate and a lower incidence of nausea and vomiting in computed tomography, magnetic resonance imaging, Auditory Brainstem Response test or fiberoptic bronchoscopy examinations than the other sedatives did (OR = 2.92; 95% CI: 1.39-6.13, P = 0.005, I2 = 51%; OR = 0.23, 95% CI: 0.07-0.68, P = 0.008, I2 = 0%, respectively). Two groups did not differ significantly in recovery time and the occurrence of adverse reactions (WMD = - 0.27, 95% CI: - 0.93 to - 0.39, P = 0.42; OR 0.70; 95% CI: 0.48-1.02, P = 0.06, I2 = 45%. respectively). However, the results of the subgroup analysis of ASA I-II children showed a quicker onset time in dexmedetomidine-midazolam group than the other sedatives (WMD=-3.08; 95% CI: -4.66 to - 1.49, P = 0.0001, I2 = 30%).

CONCLUSIONS

This meta-analysis showed that compared with the control group, dexmedetomidine combined with midazolam group provided higher sedation success rates and caused a lower incidence of nausea and vomiting in completing examinations, indicating a prospective outpatient clinical application for procedural sedation.

Comparison of Caudal Block and Dexmedetomidine Infusion in Pediatric Patients Undergoing Hypospadias Repair Surgery: A Prospective, Randomized, Double-blinded Clinical Study

Background

Many parents continue to reject caudal block since they worry about a rare neurological consequence that may happen. A parenteral surrogate is sought because it can induce recovery with features such as local analgesia.

Objectives

To compare the efficacy and safety of intravenous dexmedetomidine versus caudal and general anesthesia (GA) in children undergoing hypospadias surgery repair.

Methods

A randomized prospective study was conducted on 135 pediatric patients scheduled for hypospadias repair surgery in the hospital affiliated to Tanta University. The participants were divided into a control group (Group C) receiving GA, a caudal group receiving caudal block after GA, and a dexmedetomidine group (Group D) receiving intravenous dexmedetomidine after GA. The postoperative modified objective pain score (MOPS), the total pethidine received in the first 24 h postoperatively, and complications were recorded.

Results

The patients receiving GA required a significantly higher pethidine dose than the other two groups without a significant difference between caudal and dexmedetomidine. The patients receiving dexmedetomidine were extubated significantly later than patients in the other two groups. Regarding the MOPS score, there was a significant difference between Group C and the other two groups 30 minutes and one hour after operation regarding movements, posture, and agitation. Moreover, a significantly larger number of patients developed tachycardia in Group C compared to the other groups.

Conclusions

With the caudal block, the benefits of smooth emergency can be obtained by intravenous dexmedetomidine; however, it had less analgesic efficacy in the pediatric patients undergoing hypospadias repair surgery.

Nurse-led dexmedetomidine sedation for magnetic resonance imaging in children: a 6-year quality improvement project

We aimed to safely introduce dexmedetomidine into a nurse-led sedation service for magnetic resonance imaging in children. Secondary aims were to increase the number of children eligible for sedation and to increase the actual number of children having sedation performed by our nurse sedation team. We analysed 1768 consecutive intravenous and 219 intranasal dexmedetomidine sedation episodes in infants, children and adolescents having magnetic resonance imaging scans between March 2016 and March 2022. The overall sedation success rate was 98.4%, with a 98.9% success rate for intravenous dexmedetomidine and a 95.0% success rate for intranasal dexmedetomidine. The incidence of scan interruption during intravenous and intranasal dexmedetomidine sedation was 8.8% and 21.9%, respectively. We conclude that paediatric sedation with dexmedetomidine for magnetic resonance scanning is safe and successful.

Comparison of the Efficacy and Safety of Dexmedetomidine Administered in Two Different Modes Under Procedural Sedation and Analgesia in Plastic Surgery

Background

Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor agonist, is now widely used in procedural sedation and analgesia. This study was designed to observe and compare the efficacy and safety of DEX administered in two different modes.

Methods

In total, 100 patients were randomly divided into two groups to receive intravenous DEX 1 µg/kg over 15 min followed by 0.4–0.7 µg/kg/h infusion or DEX 1 µg/kg over 30 min followed by 0.4–0.7 µg/kg/h infusion. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), bispectral index (BIS), Ramsay Sedation Scores (RSS scores), the lowest respiratory rates (LRR), incidences of respiratory adverse events and frequencies of body movements were recorded. Recovery time, recall of intraoperative events, pain scores in PACU and satisfaction of patients and surgeons were assessed.

Results

The BIS at time points from 5 min after anesthesia to the end of surgery in the intervention group were significantly higher (p < 0.05). The RSS scores at time points from 5 min after anesthesia to immediately after induction with DEX were significantly higher in the intervention group (p < 0.05). The HR at time points from the beginning of surgery to 30 min after local anesthesia, the MAP at time points from 30 min after local anesthesia to the end of surgery, and the RR at time points from 5 min after anesthesia to the end of surgery were significantly higher in the intervention group (p < 0.05). Patients in the intervention group had higher LRR, lower incidences of respiratory adverse events, and shorter recovery time (p < 0.05).

Conclusions

Dexmedetomidine infused with a loading dose over 30 min had less impact on patients’ hemodynamics and respiration and could shorten the recovery time after anesthesia in procedural sedation and analgesia.

Clinical Trial Registration

ClinicalTrials.gov, identifier: ChiCTR1900027958.

Effect of dexmedetomidine and propofol sedation on the prognosis of children with severe respiratory failure: a systematic review and meta-analysis

BACKGROUND

During treatment of acute respiratory failure (ARF) in children, sedation can reduce pain, improve tolerance, and reduce the incidence of adverse events, so selecting an appropriate sedation strategy is very important for improving prognosis and quality of life. Both dexmedetomidine and propofol have good sedative effects, so we investigated the application of these drugs in critically ill children with ARF by literature search and meta-analysis.

METHODS

We searched Embase, The Cochrane Library, PubMed, Ovid, Clinicaltrials.org, and Google Scholar for randomized controlled trials (RCTs) preferentially but not exclusively, and used RevMan 5.4 to analyze the screened literature.

RESULTS

Seven studies were included in the quantitative meta-analysis, with a total of 1,188 patients. There was no significant difference in the effect of dexmedetomidine and propofol on the duration of tracheal intubation in children with ARF [mean difference (MD) =-0.05; 95% confidence interval (CI): (-0.42, 0.32); Z=0.26; P=0.79], but dexmedetomidine sedation could reduce the intensive care unit (ICU) stay in children with ARF [MD =-0.62; 95% CI: (-1.08, -0.16); Z=2.65; P=0.008], and shorten the total hospital stay [MD =-1.94; 95% CI: (-2.63, -1.25); Z=5.48; P<0.00001]. There was no significant effect on mortality between the two groups [odds ratio (OR) =0.48; 95% CI: (0.19, 1.25); Z=1.50; P=0.13]. The incidence rate of bradycardia with dexmedetomidine sedation was higher than with propofol [OR =12.30; 95% CI: (2.28, 66.47); Z=2.92; P=0.004], and the incidence of hypotension was also higher [OR =6.99, 95% CI: (1.22, 39.86); Z=2.19; P=0.03].

DISCUSSION

Compared with propofol, dexmedetomidine can significantly reduce the ICU stay and hospital stay. However, bradycardia and hypotension may occur during the use of dexmedetomidine, which requires close attention and timely intervention.

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.

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.

Association of dexmedetomidine with recovery room and hospital discharge times: A retrospective cohort analysis

BACKGROUND

Dexmedetomidine is a useful anesthetic adjunct, increasingly popular during pediatric surgery and procedural sedation. Its half-life of 2-3 hours might prolong recovery and discharge times when compared with an un-supplemented propofol anesthetic. This may create an additional burden in a busy post-anesthetic care unit (PACU).

AIM

To investigate whether intraoperative adjuvant dexmedetomidine delays PACU discharge in patients undergoing propofol anesthesia for day surgery or procedural investigations with minimal anticipated post-procedural pain.

METHODS

We conducted a retrospective review of outpatient procedures performed during a six-month period including pediatric patients, ASA physical status I-III, who underwent intravenous anesthesia with propofol and remifentanil for magnetic resonance imaging (MRI), strabismus repair, upper gastrointestinal endoscopy, or combined upper/lower gastrointestinal endoscopy. Patients receiving a sedative premedication, long-acting opioids, or volatile anesthetics for maintenance of anesthesia, were excluded. Duration of PACU stay was compared for patients who did or did not receive intraoperative dexmedetomidine in the four procedure groups.

RESULTS

Charts were reviewed for 359 patients; 130 (36%) received dexmedetomidine. Median differences in duration of PACU stay for dexmedetomidine versus non-dexmedetomidine cases were: 5 minutes (95%CI 0 to 10, p=0.037) for MRI; 5 minutes (95%CI -3 to 15, p=0.258) for strabismus surgery; 7 minutes (95%CI 3 to 10, p<0.001) for upper endoscopy; and 5 minutes (95%CI 1 to 12, p=0.021) for combined upper/lower endoscopy. Linear regression (F=61.1, adjusted R² =0.40) indicated a significant relationship between dexmedetomidine dose (estimate 14.6 minutes per μg/kg, 95%CI 8.2 to 21.1, p<0.001) and duration of PACU stay.

CONCLUSION

We found evidence for a small association of intraoperative dexmedetomidine with duration of recovery from propofol anesthesia for a set of common outpatient procedures, with a potential dose relationship equivalent to approximately 15 minutes delay per μg/kg dexmedetomidine administered. Future research into the benefits of dexmedetomidine in pediatric anesthesia should further evaluate this relationship.

The synergistic effect of dexmedetomidine on propofol for paediatric deep sedation: A randomised trial

BACKGROUND

Propofol and dexmedetomidine are used separately, and sometimes together, for paediatric deep sedation. Although their combination has been described in adults, the effect of dexmedetomidine as a potential synergist in children has not been studied before.

OBJECTIVES

The primary objective was to compare the propofol requirements of children who receive propofol alone with those who receive it in combination with dexmedetomidine for deep sedation for upper and lower endoscopic gastrointestinal procedures.

DESIGN

This was a prospective, open-label, randomised study comparing patients who received propofol alone (group P) with those who received dexmedetomidine and propofol (group DP). The depth of sedation was titrated to a target bispectral (BIS) index.

SETTING

A Gastroenterology Procedure Unit at a single, tertiary care academic medical centre from April 2018 until December 2019.

PATIENTS

Eligible patients were scheduled for upper endoscopy, lower endoscopy or both. A total of 39 patients were enrolled (20 DP) and (19 P).

INTERVENTIONS

Patients in Group DP received dexmedetomidine 0.5 μg kg-1 administered over 1 min followed by an infusion of 0.15 μg kg-1 h-1. In both groups, intravenous propofol was given in bolus increments titrated to a BIS index of 40 to 50 and then a continuous infusion of propofol to maintain BIS at 40 to 50.

MAIN OUTCOME MEASURES

The primary outcome measure was propofol requirement in each group. Secondary outcome measures were time to achieve the targeted sedation depth, time to achieve an Aldrete recovery score of 9, duration of sedation, mean BIS values, adverse events, 'PAED' scores and time to discharge from the postanaesthesia care unit (PACU).

RESULTS

The median (range) total dose of propofol was 0.23 (0.10 to 0.50) mg kg-1 min-1 in group DP and 0.40 (0.20 to 0.50) mg kg-1 min-1 in group P (P = 0.0004). Time of discharge from the PACU was 60 (20 to 121) min in group DP and 63 (46 to 91) min in group P (P = 0.0409).

CONCLUSION

The combination of dexmedetomidine and propofol for paediatric procedural sedation achieved a significant reduction in median propofol dose and a slightly shorter median time to discharge from PACU. Large-scale studies may determine whether this reduction decreases the risk of significant adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02952222.

The effect of intraoperative dexmedetomidine administration on length of stay in the post-anesthesia care unit in ambulatory surgery: A hospital registry study

STUDY OBJECTIVE

Dexmedetomidine, which is commonly used for procedural sedation and as adjunct to general anesthesia for ambulatory procedures, may affect patient discharge from the post-anesthesia care unit (PACU). We hypothesized that intraoperative dexmedetomidine use in ambulatory surgery is associated with delayed discharge from the PACU and that this is modified by surgical duration and anesthesia type.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENTS

130,854 adult patients undergoing ambulatory surgery between 2008 and 2018.

INTERVENTIONS

Intraoperative administration of dexmedetomidine.

MEASUREMENTS

The primary outcome was PACU length of stay. In secondary and exploratory analyses, we examined dose-dependency, effect modification by duration of surgery and anesthesia type, effects of timing of dexmedetomidine administration, and PACU discharge delays.

MAIN RESULTS

Dexmedetomidine was associated with a prolonged PACU length of stay (adjusted absolute difference [AD_adj] 15.0 min; 95%CI 12.7-17.3; p < 0.001). This effect was dose-dependent (p-for-trend < 0.001), magnified in surgeries of less than one hour (AD_adj 20.7 min; 95%CI 16.7-24.7; p < 0.001) and in patients undergoing monitored anesthesia care compared to general anesthesia (AD_adj 16.8 min; 95%CI 14.1-19.6; p < 0.001). The effect was more pronounced if dexmedetomidine was administered within the last 60 min of surgery (AD_adj 18.7 min; 95%CI 15.7-21.7; p < 0.001). Dexmedetomidine was associated with discharge delays due to cardiovascular complications (OR_adj 2.27; 95%CI 1.59-3.24; p < 0.001) and over-sedation (OR_adj 1.28; 95%CI 1.11-1.48; p < 0.001). In patients who received dexmedetomidine (n = 2901), the use of bolus doses only versus the combination of bolus and infusions, magnified the effects on PACU length of stay (AD_adj 29.5 min per μg/kg; 95%CI 17.3-41.8 versus 18.1 min per μg/kg; 95%CI 11.4-24.8; p < 0.001).

CONCLUSIONS

The intraoperative administration of dexmedetomidine was dose-dependently associated with a prolonged PACU length of stay. Clinicians should judiciously titrate dexmedetomidine, especially when using this long-acting drug for monitored anesthesia care for shorter procedures.

A Comparison of Safety and Efficacy of Dexmedetomidine and Propofol in Children with Autism and Autism Spectrum Disorders Undergoing Magnetic Resonance Imaging

Children with autism and autism spectrum disorders have a high incidence of neurologic comorbidities. Consequently, evaluation with magnetic resonance imaging (MRI) is deemed necessary. Sedating these patients poses several challenges. This retrospective study compared the efficacy and safety of dexmedetomidine to propofol in sedating autistic patients undergoing MRI. There were 56 patients in the dexmedetomidine group and 49 in the propofol group. All of the patients successfully completed the procedure. Recovery and discharge times were significantly lower in the propofol group, while the dexmedetomidine group maintained more stable hemodynamics. Both propofol and dexmedetomidine proved to be adequate and safe medications in the sedation of autistic children undergoing MRI.

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.

Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures

The safe sedation of children for procedures requires a systematic approach that includes the following: no administration of sedating medication without the safety net of medical/dental supervision, careful presedation evaluation for underlying medical or surgical conditions that would place the child at increased risk from sedating medications, appropriate fasting for elective procedures and a balance between the depth of sedation and risk for those who are unable to fast because of the urgent nature of the procedure, a focused airway examination for large (kissing) tonsils or anatomic airway abnormalities that might increase the potential for airway obstruction, a clear understanding of the medication's pharmacokinetic and pharmacodynamic effects and drug interactions, appropriate training and skills in airway management to allow rescue of the patient, age- and size-appropriate equipment for airway management and venous access, appropriate medications and reversal agents, sufficient numbers of appropriately trained staff to both carry out the procedure and monitor the patient, appropriate physiologic monitoring during and after the procedure, a properly equipped and staffed recovery area, recovery to the presedation level of consciousness before discharge from medical/dental supervision, and appropriate discharge instructions. This report was developed through a collaborative effort of the American Academy of Pediatrics and the American Academy of Pediatric Dentistry to offer pediatric providers updated information and guidance in delivering safe sedation to children.

Sedation Strategies for Procedures Outside the Operating Room

With the rapid development of diagnostic and therapeutic procedures performed outside the operating room (OR), the need for appropriate sedation care has emerged in importance to ensure the safety and comfort of patients and clinicians. The preparation and administration of sedatives and sedation care outside the OR require careful attention, proper monitoring systems, and clinically useful sedation guidelines. This literature review addresses proper monitoring and selection of sedatives for diagnostic and interventional procedures outside the OR. As the depth of sedation increases, respiratory depression and cardiovascular suppression become serious, necessitating careful surveillance using appropriate monitoring equipment.

Non-operating room anaesthesia in children

Administration of sedation and/or anaesthesia to patients undergoing painful or uncomfortable procedures at off-site locations is referred to as non-operating room anaesthesia (NORA). Sedating/anaesthetising children in an unfamiliar environment, with the lack of support staff, nonavailability of choice of medication and equipment is often challenging. Studies have shown an increased risk of airway-related adverse events, complications, and even death outside the operating room locations. It is crucial to be familiar with the anatomical and physiological variations in children, well versed with the difficult airway algorithm and call for help early. The most common event in NORA claims was inadequate oxygenation/ventilation, which are preventable with vigilant monitoring. English language articles were searched in Pubmed, Google Scholar, and Academic using 'sedation in children', 'remote location anaesthesia', 'peadiatric sedation', and 'nonoperating room anaesthesia' as the mesh words. Full text of the relevant articles was obtained and this review article was synthesised. The article outlines various safety guidelines, sedation techniques, drugs used for sedation, environmental concerns, procedure-specific risks, and complications associated with NORA in children.

A retrospective comparison of propofol to dexmedetomidine for pediatric magnetic resonance imaging sedation in patients with mucopolysaccharidosis type II

BACKGROUND

Mucopolysaccharidosis type II patients are reported to have an elevated incidence of difficult airway. Propofol is a commonly used sedative for magnetic resonance imaging in pediatric patients, but patients who receive it may exhibit dose-dependent upper airway obstruction and respiratory depression. Dexmedetomidine also provides adequate procedural sedation with a relatively low risk of airway obstruction. Accordingly, we introduced the use of dexmedetomidine in our practice to reduce the risk of airway obstruction during magnetic resonance imaging procedures.

AIMS

The aim of this study was to evaluate the incidence of artificial airway interventions in patients sedated with propofol and compare it to that in patients sedated with dexmedetomidine in patients with mucopolysaccharidosis type II during magnetic resonance imaging procedures.

METHODS

All mucopolysaccharidosis type II patients undergoing magnetic resonance imaging at our institution between April 2014 and February 2018 were included in this study. The patients were divided into two groups according to whether they were managed before and after the introduction of dexmedetomidine: those who were sedated with propofol (group P) and those who were sedated with dexmedetomidine (group D).

RESULTS

Forty-six sedations were performed in 27 patients. Artificial airway interventions were significantly more frequent during propofol-based than dexmedetomidine-based sedation: 14 of 32 (43.8%) in group P and 1 of 14 (7.1%) in group D (odds ratio, 10.11; 95% confidence interval, 1.18-86.85; P = 0.018). Time to awake and time to discharge were similar between groups. Changes in hemodynamic variables also did not significantly differ between groups.

CONCLUSION

Dexmedetomidine provides an adequate level of sedation and is associated with lower rates of artificial airway interventions compared to propofol. Therefore, dexmedetomidine may offer advantages for preserving the native airway compared to propofol when administered during magnetic resonance imaging scans in patients with mucopolysaccharidosis type II.

Comparison of dexmedetomidine and ketamine versus propofol and ketamine for procedural sedation in children undergoing minor cardiac procedures in cardiac catheterization laboratory

BACKGROUND

The ideal anaesthetic technique for management of paediatric patients scheduled to undergo cardiac catheterisation is still not standardised.

AIM

To compare the effects of ketamine-propofol and ketamine-dexmedetomidine combinations on hemodynamic parameters and recovery time in paediatric patients undergoing minor procedures and cardiac catheterisation under sedation for various congenital heart diseases.

MATERIAL AND METHODS

60 children of either sex undergoing cardiac catheterisation were randomly assigned into two groups Dexmedetomidine-ketamine group (DK) and Propofol-ketamine (PK) of 30 patients each. All patients were premedicated with glycopyrrolate and midazolam (0.05mg/kg) intravenously 5-10 min before anaesthetic induction. Group 'DK'received dexmedetomidineiv infusion 1 μg/kg over 10 min + ketamine1mg/kg bolus, followed by iv infusion of dexmedetomidine 0.5μg/kg/hr and of ketamine1 mg/kg/hr. Group 'PK' received propofol 1mg/kg and ketamine 1mg/kg/hr for induction followed by iv infusion of propofol 100 μg/kg/hr and ketamine 1 mg/kg/hr for maintenance. Haemodynamic parameters and recovery time was recorded postoperatively.

STATISTICAL ANALYSIS

Independent sample t test was used to compare the statistical significance of continuous variables of both the groups.Chi square test was used for numerical data like gender.Fischer exact test was applied for non parametric data like ketamine consumption.

RESULTS

We observed that heart rate in dexmedetomidine (DK) group was significantly lower during the initial 25 mins after induction compared to the propofol (PK) group. Recovery was prolonged in the DK group compared to the PK group (40.88 vs. 22.28 min). Even ketamine boluses consumption was higher in DK group.

CONCLUSION

Use of dexmedetomidine-ketamine combination is a safe alternative, without any hemodynamic orrespiratory effects during the cardiac catheterization procedure but with some delayed recovery.

Advanced maxillofacial imaging for temporomandibular disorder in special needs patients

Temporomandibular disorder (TMD) is prevalent in special needs patients. Clinical examination of the temporomandibular joint (TMJ) complex and imaging in this patient population can be challenging due to patient disposition and cooperation. We report a case of a 29-year-old male with neurologic and behavioral special needs who required advanced maxillofacial imaging for a suspected TMD under general anesthesia, which has not been reported previously. This article intends to serve as a resource for health care providers who may encounter similar clinical situations.

Neuroprotection and neurotoxicity in the developing brain: an update on the effects of dexmedetomidine and xenon

Growing and consistent preclinical evidence, combined with early clinical epidemiological observations, suggest potentially neurotoxic effects of commonly used anesthetic agents in the developing brain. This has prompted the FDA to issue a safety warning for all sedatives and anesthetics approved for use in children under three years of age. Recent studies have identified dexmedetomidine, the potent α2-adrenoceptor agonist, and xenon, the noble gas, as effective anesthetic adjuvants that are both less neurotoxic to the developing brain, and also possess neuroprotective properties in neonatal and other settings of acute ongoing neurologic injury. Dexmedetomidine and xenon are effective anesthetic adjuvants that appear to be less neurotoxic than other existing agents and have the potential to be neuroprotective in the neonatal and pediatric settings. Although results from recent clinical trials and case reports have indicated the neuroprotective potential of xenon and dexmedetomidine, additional randomized clinical trials corroborating these studies are necessary. By reviewing both the existing preclinical and clinical evidence on the neuroprotective effects of dexmedetomidine and xenon, we hope to provide insight into the potential clinical efficacy of these agents in the management of pediatric surgical patients.

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.

Evaluation of efficacy of dexmedetomidine versus propofol for sedation in children undergoing magnetic resonance imaging

Background:

A deep level of sedation is required for magnetic resonance imaging (MRI) in children to ensure optimum image quality. The present study was conducted to evaluate the efficacy and safety of dexmedetomidine versus propofol for sedation in children undergoing MRI.

Materials and Methods:

A total of sixty children aged 2–10 years, having physical status 1 or 2 according to the American Society of Anesthesiologists, undergoing MRI were included in the study. Group D: (n = 30) received injection dexmedetomidine 2 μg/kg for 10 min followed by continuous infusion of 1.0 μg/kg/h. Group P (n = 30) received injection propofol 1 mg/kg bolus followed by continuous infusion of 100 μg/kg/min.

Results:

The mean time for onset of sedation in Group D was much longer than in Group P (P = 0.000). Mean duration of sedation was comparable in the two groups. The number of patients requiring increased infusion of study drug was significantly higher in Group D (30%) as compared to Group P (16.7%) (P < 0.05). The average recovery time in Group D was much longer than in Group P (P < 0.001).

Conclusion:

Propofol had an advantage of providing rapid onset of sedation and quicker recovery time. Dexmedetomidine resulted in a better preservation of respiratory rate and oxygen saturation, so it may be more suitable in children who are prone to respiratory depression. Hence, both the drugs could achieve required sedation in children posted for MRI.

Does dexmedetomidine cause less airway collapse than propofol when used for deep sedation?

STUDY OBJECTIVE

The risk of airway collapse in patients undergoing deep sedation is a major concern. In this study, we compared the airway patency of deep sedation provided by propofol with the airway patency of deep sedation provided by dexmedetomidine in magnetic resonance imaging (MRI) procedures. This comparison was done using MRI static and dynamic images and comparing these images to baseline after sevoflurane induction.

DESIGN

After institutional review board approval, children who were scheduled for MRI procedures were given an inhalation induction, had intravenous access established, and were randomized to receive either dexmedetomidine 1-μg/kg load followed by 1-μg/(kg h) infusion or propofol infusion at 300 μg/(kg min) reduced to 250-μg/(kg min) infusion. MR images were then obtained. Airway patency and collapse were assessed at the level of the posterior midtongue in the axial and sagittal planes. The degree of airway collapse was assessed by determining the percent change in the airway caliber from its minimum to maximum value. After conclusion of the MRI procedure, the study patients were immediately observed by a blinded observer to determine their level of sedation according to the Ramsey sedation scale.

SETTING

MRI scanner at Women and Children's Hospital of Buffalo.

PATIENTS

Forty children between the ages of 3 and 7 years.

INTERVENTION

Comparison of the utilization of propofol against dexmedetomidine infusions for deep sedation to determine the degree of airway collapse.

MEASUREMENTS

Magnetic resonance images were then obtained using a 1.5-T GE Excite 12.0 scanner. Airway patency and collapse were assessed at the level of the posterior midtongue in the axial and sagittal planes. The degree of airway collapse was assessed by determining the percent change in the airway caliber from its minimum to maximum value. After conclusion of the MRI procedure, the study patients were immediately observed by a blinded observer to determine their level of sedation according to the Ramsey sedation scale.

MAIN RESULTS

Our study demonstrated no difference in airway collapse between dexmedetomidine-based deep sedation and propofol-based deep sedation following sevoflurane induction.

CONCLUSION

In deep sedation, which is commonly associated with a loss of airway tone, it may not matter which of these intravenous study agents are used. Intravenous sedation with propofol or dexmedetomidine appears to produce the same effect on the pediatric airway.

Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures: Update 2016

The safe sedation of children for procedures requires a systematic approach that includes the following: no administration of sedating medication without the safety net of medical/dental supervision, careful presedation evaluation for underlying medical or surgical conditions that would place the child at increased risk from sedating medications, appropriate fasting for elective procedures and a balance between the depth of sedation and risk for those who are unable to fast because of the urgent nature of the procedure, a focused airway examination for large (kissing) tonsils or anatomic airway abnormalities that might increase the potential for airway obstruction, a clear understanding of the medication's pharmacokinetic and pharmacodynamic effects and drug interactions, appropriate training and skills in airway management to allow rescue of the patient, age- and size-appropriate equipment for airway management and venous access, appropriate medications and reversal agents, sufficient numbers of staff to both carry out the procedure and monitor the patient, appropriate physiologic monitoring during and after the procedure, a properly equipped and staffed recovery area, recovery to the presedation level of consciousness before discharge from medical/dental supervision, and appropriate discharge instructions. This report was developed through a collaborative effort of the American Academy of Pediatrics and the American Academy of Pediatric Dentistry to offer pediatric providers updated information and guidance in delivering safe sedation to children.

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.

Comparing the efficacy and safety between propofol and dexmedetomidine for sedation in claustrophobic adults undergoing magnetic resonance imaging (PADAM trial)

STUDY OBJECTIVE

To determine the efficacy of sedation with dexmedetomidine compared to propofol for claustrophobic adults undergoing magnetic resonance imaging (MRI) in our institution.

DESIGN

Randomized, prospective, double-blinded study.

SETTING

University-based tertiary referral center.

PATIENTS

Thirty claustrophobic adults with American Society of Anesthesiologists physical status I and II who were planned for MRI.

INTERVENTIONS

Patients were randomly assigned to target-controlled infusion propofol or dexmedetomidine loading followed by maintenance dose for procedural sedation.

MEASUREMENTS AND MAIN RESULTS

The primary end point was adequate reduction in patient anxiety levels to allow successful completion of the MRI sequence. Both methods of sedation adequately reduced anxiety levels in visual analog scale scores and Spielberger Strait Test Anxiety Inventory (P<.001). Dexmedetomidine required a longer time to achieve anxiolysis, 7.36minutes (SD, 2.59), and required increasing maintenance dose to induce sleep compared to 10.71minutes (SD, 4.63) for propofol. In terms of image quality, 2 patients (16.67%) in the dexmedetomidine group were satisfactory, whereas all with propofol were graded as good to excellent. Adverse effects were seen in patients sedated with dexmedetomidine with number needed to harm 8 for hypotension and 15 for bradycardia compared to none recorded in the propofol arm. There was no significant difference in patient satisfaction scores or home readiness after the MRI.

CONCLUSIONS

Both dexmedetomidine and propofol can effectively reduce anxiety levels of claustrophobic adults undergoing MRI, but dexmedetomidine takes longer to achieve adequate anxiolysis and sleep and may have an effect on image quality. Hypotension and bradycardia are common adverse effects observed with dexmedetomidine.

Dexmedetomidine vs midazolam as preanesthetic medication in children: a meta-analysis of randomized controlled trials

INTRODUCTION

The preoperative period is a stressing occurrence for most people undergoing surgery, in particular children. Approximately 50-75% of children undergoing surgery develop anxiety which is associated with distress on emergence from anesthesia and with later postoperative behavioral problems. Premedication, commonly performed with benzodiazepines, reduces preoperative anxiety, facilitates separation from parents, and promotes acceptance of mask induction. Dexmedetomidine is a highly selective α2 -agonist with sedative and analgesic properties. A meta-analysis of all randomized controlled trials (RCTs) on dexmedetomidine versus midazolam was performed to evaluate its efficacy in improving perioperative sedation and analgesia, and in reducing postoperative agitation when used as a preanesthetic medication in children.

METHODS

Studies were independently searched in PubMed, BioMedCentral, Embase, and the Cochrane Central Register of clinical trials and updated on August 15th, 2014. Primary outcomes were represented by improved sedation at separation from parents, at induction of anesthesia, and reduction in postoperative agitation. Secondary outcomes were reduction in rescue analgesic drugs, and duration of surgery and anesthesia. Inclusion criteria were random allocation to treatment and comparison between dexmedetomidine and midazolam. Exclusion criteria were adult studies, duplicate publications, intravenous administration, and no data on main outcomes.

RESULTS

Data from 1033 children in 13 randomized trials were analyzed. Overall, in the dexmedetomidine group there was a higher incidence of satisfactory sedation at separation from parents (314 of 424 [74%] in the dexmedetomidine group vs 196 of 391 [50%] in the midazolam group, RR = 1.30 [1.05-1.62], P = 0.02), a reduced incidence of postoperative agitation (14 of 140 [10%] vs 56 of 141 [40%], RR = 0.31 [0.13-0.73], P = 0.008), and a significant reduction in the rescue doses of analgesic drugs (49 of 241 [20%] vs 95 of 243 [39%], RR = 0.52 [0.39-0.70], P < 0.001). There was no evidence of a higher incidence of satisfactory sedation at anesthesia induction or any reduction of duration of surgery and anesthesia.

CONCLUSIONS

Dexmedetomidine is effective in decreasing anxiety upon separation from parents, decreasing postoperative agitation, and providing more effective postoperative analgesia when compared with midazolam.

Effect of a neck collar on upper airway size in children sedated with propofol-midazolam combination during magnetic resonance imaging

INTRODUCTION

Propofol and midazolam are widely used for pediatric magnetic resonance imaging (MRI) sedation. Increasing depth of sedation may be associated with airway obstruction. A neck collar supporting the mandible and maintaining the head in slight extension may be beneficial in maintaining airway patency.

AIM OF THE STUDY

Primary aim: To assess upper airway size with and without a neck collar during pediatric MRI sedation with propofol-midazolam. Secondary aim: To evaluate complications encountered during the procedure.

MATERIALS AND METHODS

Sixty patients aged 2-4 years scheduled for MRI of the brain were selected. They were sedated with intramuscular midazolam 0.1 mg·kg(-1) 30 min before the procedure. Patients were sedated with i.v. propofol 1 mg·kg(-1) and continued with 50-100 μg·kg(-1) ·min(-1) . T1 3D fast-field echo axial sequence from the nasopharyngeal roof to subglottic region was taken with and without application of a neck collar. Airway dimensions were measured and analyzed at the base of the tongue, soft palate, and at the epiglottis.

RESULTS

At the base of the tongue and soft palate, the cross-sectional area (CSA) and the anteroposterior diameter of the airway were respectively statistically significantly higher when the neck collar was applied. The CSA at the epiglottis was significantly less with application of the neck collar. Complications were not significantly different between the two sequences.

CONCLUSION

Application of a soft neck collar in children aged 2-4 years may enhance the retropalatal and retroglossal airway dimensions during pediatric sedation in the supine position.

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.

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.

Comparison of propofol and dexmedetomedine techniques in children undergoing magnetic resonance imaging

BACKGROUND

Propofol (PRO) and dexmedetomidine (DEX) are commonly used to produce anesthesia and sedation for routine MRI procedures. Children with complex conditions often require much lengthy MRI for multi-body-part scans with frequent scanner coil changes and patient body reposition. This study compared PRO and DEX techniques on outcomes for the particular MRI setting with longer than 1 h duration.

METHODS

95 children, aged from 1 to 7 years, scheduled for MRI >75 min were randomly assigned to PRO or DEX group. After induced with sevoflurane, a loading dose of PRO (2 mg·kg(-1)) was administrated and followed by continuous infusion (200 μg·kg(-1) ·min(-1)); a loading dose of DEX (2 μg·kg(-1)) was administrated and followed by continuous infusion (2 μg·kg(-1) ·h(-1)). Patients received O(2) by nasal cannula. The observed outcomes were times for induction, MRI, emergence, and recovery, and total time (induction to discharge); MRI pauses from patient movement; incidence of technique failure and critical events; emergence and behavior in postanesthesia care unit (PACU); parental satisfaction; and arterial pressure (BP) and heart rate (HR) during anesthesia.

RESULTS

PRO compared with DEX showed significantly less time for anesthesia induction (16.3 versus 24.2 min), emergence (21.2 versus 39.9 min), PACU (35.7 versus 62.5 min), and total time (135 versus 173 min) (all P < 0.001). There were significantly fewer pauses during MRI and lower failure rate to complete MRI in PRO versus DEX (0.22 versus 0.81, P = 0.01 and 1 versus 15, P < 0.001), less behavioral disturbances in PACU, and higher parental satisfaction in PRO versus DEX (P < 0.01). There were no critical events in either group: In PRO, mean BP during MRI (from 52 ± 8 to 58 ± mmHg) was significantly less than before anesthesia (80 ± 12 mmHg), while HR remained relatively constant (range of 97-103) at its baseline of 108 ± 21, but in DEX, mean BP remained unchanged (from 76 ± 12 to 78 ± 15) during anesthesia compared with before anesthesia (79 ± 14 mmHg), while HR decreased (74 ± 16 to 78 ± 15) during anesthesia from its baseline (102 ± 17).

CONCLUSION

For children undergoing lengthy multicomponent MRI, the propofol technique yielded overall better outcomes than the dexmedetomedine technique in terms of timeliness, PACU emergence characteristics, and parental satisfaction.

Preemptive dexmedetomidine to prevent propofol injection pain in children

BACKGROUND

The incidence of propofol injection pain is high in children, but no methods have been found to suppress it completely. This study intends to evaluate the efficacy of dexmedetomidine-midazolam in preventing propofol injection pain in children.

METHODS

One-hundred ASA I patients, aged 3-12 years, weighing 15-53 kg, undergoing elective surgery were randomized into two groups of 50 each, using computer-generated random numbers. Normal saline 0.15 ml/kg in Group C or dexmedetomidine 0.6 μg/kg in Group D was infused IV over 10 min. Then midazolam 0.06 mg/kg was administered immediately; 2 min after aforementioned treatments in each group, all patients received propofol 2 mg/kg (propofol was mixed with lidocaine 1 mg/ml in Group C) at an average rate of 0.2 ml per 1 s. Another anesthesiologist, blind to the pretreatment, recorded the occurrence of injection pain using a four-graded pain scale: 1 = no pain (no reaction to injection), 2 = slight pain (minor verbal/facial response or motor reaction to injection), 3 = moderate pain (clear verbal/facial response or motor reaction to injection) and 4 = severe pain (the patient both complained of pain and withdrew the arm).

RESULTS

Forty (80 %) patients in Group C (control) had injection pain; however, none of patients in Group D had any injection pain. The total incidence of profol-induced pain in Group C was significantly higher (P < 0.01). There were no instances of bradycardia or low blood pressure with either treatment in this study.

CONCLUSIONS

Pretreatment with dexmedetomidine 0.6 μg/kg, then midazolam 0.06 mg/kg could suppress propofol injection pain in children.

An evaluation of intranasal sufentanil and dexmedetomidine for pediatric dental sedation

Conscious or moderate sedation is routinely used to facilitate the dental care of the pre- or un-cooperative child. Dexmedetomidine (DEX) has little respiratory depressant effect, possibly making it a safer option when used as an adjunct to either opioids or benzodiazepines. Unlike intranasal (IN) midazolam, IN application of DEX and sufentanil (SUF) does not appear to cause much discomfort. Further, although DEX lacks respiratory depressive effects, it is an α2-agonist that can cause hypotension and bradycardia when given in high doses or during prolonged periods of administration. The aim of this feasibility study was to prospectively assess IN DEX/SUF as a potential sedation regimen for pediatric dental procedures. After IRB approval and informed consent, children (aged 3-7 years; n = 20) from our dental clinic were recruited. All patients received 2 μg/kg (max 40 μg) of IN DEX 45 min before the procedure, followed 30 min later by 1 μg/kg (max 20 μg) of IN SUF. An independent observer rated the effects of sedation using the Ohio State University Behavior Rating Scale (OSUBRS) and University of Michigan Sedation Scale (UMSS). The dentist and the parent also assessed the efficacy of sedation. Dental procedures were well tolerated and none were aborted. The mean OSUBRS procedure score was 2.1, the UMSS procedure score was 1.6, and all scores returned to baseline after the procedure. The average dentist rated quality of sedation was 7.6 across the 20 subjects. After discharge, parents reported one child with prolonged drowsiness and one child who vomited at home. The use of IN DEX supplemented with IN SUF provided both an effective and tolerable form of moderate sedation. Although onset and recovery are slower than with oral (PO) midazolam and transmucosal fentanyl, the quality of the sedation may be better with less risk of respiratory depression. Results from this preliminary study showed no major complications from IN delivery of these agents.

Short-term reduction in intrinsic heart rate during biventricular pacing after cardiac surgery: a substudy of a randomized clinical trial

BACKGROUND

The Biventricular Pacing After Cardiac Surgery trial investigates hemodynamics of temporary pacing in selected patients at risk of left ventricular dysfunction. This trial demonstrates improved hemodynamics during optimized biventricular pacing compared with atrial pacing at the same heart rate 1 and 2 hours after bypass and reduced vasoactive-inotropic score over the first 4 hours after bypass. However, this advantage of biventricular versus atrial pacing disappears 12 to 24 hours later. We hypothesized that changes in intrinsic heart rate can explain variable effects of atrial pacing in this setting.

METHODS

Heart rate, mean arterial pressure, cardiac output, and medications depressing heart rate were analyzed in patients randomized to continuous biventricular pacing (n = 16) or standard of care (n = 18).

RESULTS

During 30-second testing periods without pacing, intrinsic heart rate was lower in the paced group 12 to 24 hours after bypass (76.5 ± 17.5 vs 91.7 ± 13.0 beats per minute; P = .040) but not 1 or 2 hours after bypass. Cardiac output (4.4 ± 1.2 vs 3.6 ± 1.9 L/min; P = .054) and stroke volume (53 ± 2 vs 42 ± 2 mL; P = .051) increased overnight in the paced group. Vasoactive medication doses were not different between groups, whereas dexmedetomidine administration was prolonged over postoperative hours 12 to 24 in the paced group (793 ± 528 vs 478 ± 295 minutes; P = .013).

CONCLUSIONS

These observations suggest that hemodynamic benefits of biventricular pacing 12 to 24 hours after cardiopulmonary bypass lead to withdrawal of sympathetic drive and decreased intrinsic heart rate. Depression of intrinsic rate increases the apparent benefit of atrial pacing in the chronically paced group but not in the control group. Additional study is needed to define clinical benefits of these effects.

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.

Sedation/anaesthesia in paediatric radiology

OBJECTIVES

In this article we will give a comprehensive literature review on sedation/general anaesthesia (S/GA) and discuss the international variations in practice and options available for S/GA for imaging children.

METHODS

The key articles were obtained primarily from PubMed, MEDLINE, ERIC, NHS Evidence and The Cochrane Library.

RESULTS

Recently, paediatric radiology has seen a surge of diagnostic and therapeutic procedures, some of which require children to be still and compliant for up to 1 h. It is difficult and sometimes even impossible to obtain quick and high-quality images without employing sedating techniques in certain children. As with any medical procedure, S/GA in radiological practice is not without risks and can have potentially disastrous consequences if mismanaged. In order to reduce any complications and practice safety in radiological units, it is imperative to carry out pre-sedation assessments of children, obtain parental/guardian consent, monitor them closely before, during and after the procedure and have adequate equipment, a safe environment and a well-trained personnel.

CONCLUSION

Although the S/GA techniques, sedative drugs and personnel involved vary from country to country, the ultimate goal of S/GA in radiology remains the same; namely, to provide safety and comfort for the patients. Advances in knowledge Imaging children under general anaesthesia is becoming routine and preferred by operators because it ensures patient conformity and provides a more controlled environment.

Preliminary experience with a combination of dexmedetomidine and propofol infusions for diagnostic cardiac catheterization in children

No specific regimen has been universally accepted as ideal for procedural sedation during cardiac catheterization in infants and children. In this paper, we retrospectively describe our preliminary experience with a continuous infusion of dexmedetomidine and propofol for sedation during cardiac catheterization in children with congenital heart disease. The short-half life of these two drugs creates a potential for easier titration, quicker recovery and less prolonged sedation-related adverse effects. This combination was not only able to limit the dose of either drugs, but was also very stable from cardio-respiratory standpoint. There were no adverse effects noted in our two patients. This initial experience showed that the combination of propofol and dexmedetomidine as a continuous infusion may be a suitable alternative for sedation in spontaneously breathing children undergoing cardiac catheterization.

Is the addition of dexmedetomidine to a ketamine-propofol combination in pediatric cardiac catheterization sedation useful?

Pediatric patients undergoing cardiac catheterization usually need deep sedation. In this study, 60 children were randomly allocated to receive sedation with either a ketamine-propofol combination (KP group, n = 30) or a ketamine-propofol-dexmedetomidine combination (KPD group, n = 30). Both groups received 1 mg/kg of ketamine and 1 mg/kg of propofol for induction of sedation, and the KPD group received an additional 1 μg/kg of dexmedetomidine infusion during 5 min for induction of sedation and a maintenance infusion of 0.5 μg/kg/h. In both groups, 0.2 mg/kg of propofol was administered as a bolus to maintain a Ramsey sedation score (RSS) greater than 4 throughout the procedure. None of the patients in either group required intubation. In the KP group, one patient required mask ventilation. The chin-lift maneuver needed to be performed for eight patients in the KP group and one patient in the KPD group (p < 0.05). Adding dexmedetomidine to the ketamine-propofol combination decreased movement during the procedures. The heart rate in the KPD group was significantly lower after induction of sedation and throughout the procedure (p < 0.05). No significant differences in systolic blood pressure, diastolic blood pressure, or respiration rates were found between the two groups (p > 0.05). The mean recovery time was longer in the KP group (5.86 vs 3.13 min; p < 0.05). Adding dexmedetomidine to a ketamine-propofol combination led to a reduced need for airway intervention and to decreased movement during local anesthetic infiltration and throughout the procedure. The recovery time was shorter and hemodynamic stability good in the KPD group.

Hemodynamic characteristics of midazolam, propofol, and dexmedetomidine in healthy volunteers

STUDY OBJECTIVE

To study the effect of intravenous (IV) sedation on blood pressure (BP), heart rate (HR), and respiratory rates (RR) to determine if IV sedatives differ with respect to their effect on BP, HR, and RR.

DESIGN

Prospective, randomized, single-blinded, placebo-controlled study.

SETTING

Monitored patient care room at a clinical research center.

SUBJECTS

60 healthy ASA physical status 1 volunteers.

INTERVENTIONS

Subjects were randomized to receive, in increasing doses, one of three IV sedatives: propofol, midazolam, or dexmedetomidine; or saline control.

MEASUREMENTS

Blood pressure (systolic, diastolic), HR, and RR were recorded.

MAIN RESULTS

A significant dose-dependent BP reduction occurred with dexmedetomidine and, to a lesser degree, with propofol; and there was good agreement of predicted versus measured drug concentrations for all sedatives. Blood pressure and HR of participants who received midazolam did not change.

CONCLUSIONS

When administered in sedative doses, dexmedetomidine and, to a lesser extent, midazolam, reduces BP in a dose-dependent fashion. Dexmedetomidine also reduces HR. Midazolam does not affect BP or HR.