Anesthetics influence concussive head injury induced blood-brain barrier breakdown, brain edema formation, cerebral blood flow, serotonin levels, brain pathology and functional outcome

Several lines of evidences show that anesthetics influence neurotoxicity and neuroprotection. The possibility that different anesthetic agents potentially influence the pathophysiological and functional outcome following neurotrauma was examined in a rat model of concussive head injury (CHI). The CHI was produced by an impact of 0.224N on the right parietal bone by dropping a weight of 114.6g from a 20cm height under different anesthetic agents, e.g., inhaled ether anesthesia or intraperitoneally administered ketamine, pentobarbital, equithesin or urethane anesthesia. Five hour CHI resulted in profound volume swelling and brain edema formation in both hemispheres showing disruption of the blood-brain barrier (BBB) to Evans blue and radioiodine. A marked decrease in the cortical CBF and a profound increase in plasma or brain serotonin levels were seen at this time. Neuronal damages were present in several parts of the brain. These pathological changes were most marked in CHI under ether anesthesia followed by ketamine (35mg/kg, i.p.), pentobarbital (50mg/kg, i.p.), equithesin (3mL/kg, i.p.) and urethane (1g/kg, i.p.). The functional outcome on Rota Rod performances or grid walking tests was also most adversely affected after CHI under ether anesthesia followed by pentobarbital, equithesin and ketamine. Interestingly, the plasma and brain serotonin levels strongly correlated with the development of brain edema in head injured animals in relation to different anesthetic agents used. These observations suggest that anesthetic agents are detrimental to functional and pathological outcomes in CHI probably through influencing the circulating plasma and brain serotonin levels, not reported earlier. Whether anesthetics could also affect the efficacy of different neuroprotective agents in CNS injuries is a new subject that is currently being examined in our laboratory.

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.

Conscious Intravenous Sedation in Dentistry: A Review of Current Therapy

Several sedation options are used to minimize pain, anxiety, and discomfort during oral surgery procedures. Minimizing or eliminating pain and anxiety for dental care is the primary goal for conscious sedation. Intravenous conscious sedation is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate as well as cardiovascular function. Patients must retain their protective airway reflexes, and respond to and understand verbal communication. The drugs and techniques used must therefore carry a broad margin of safety.

Complications of three deep sedation methods for magnetic resonance imaging

Background:

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

Aim/Objective:

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

Materials and Methods:

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

Results:

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

Conclusions:

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

Sedation and anesthesia issues in pediatric imaging

Sedation and anesthesia for pediatric imaging departments has changed dramatically for the following reasons: (1) radiologists have stopped sedating patients; (2) the majority of sedations are not for CT (because of the speed of the procedure) but for MR, which lasts 45 min or greater; (3) a cadre of services--pediatricians, emergency medicine physicians, hospitalists and intensivists, as well as anesthesiologists--can provide the services. These changes have significantly influenced the type of agents utilized for sedation and anesthesia and, most important, have created operational issues for MR departments. Nevertheless, it is important for each imaging department to create a uniform approach to sedation, taking into account patient expectations, efficiency of through-put, facilities and personnel available, and institutional costs.

Effect of anesthesia and sedation on pediatric MR imaging patient flow

PURPOSE

To determine the effect of sedative and anesthetic administration on the duration and costs of pediatric magnetic resonance (MR) imaging.

MATERIALS AND METHODS

This prospective study was approved by the institutional research ethics board; informed consent and/or assent was obtained from all participants or their parents. A patient flow study was conducted in a pediatric MR imaging clinic in which research assistants tracked participants' progress through the clinic. Demographic, visit process, and medication information was collected for 237 participants, categorized as awake, sedated, or anesthetized. The data were analyzed to (a) determine total visit duration differences, (b) investigate variations in visit stage durations according to patient type, and (c) estimate visit costs on the basis of human resource and medication use. Linear regression, the Shapiro-Wilk test, the two-tailed t test, and the nonparametric Mann-Whitney test were used.

RESULTS

Complete data sets were obtained for 148 awake, 28 sedated, and 27 anesthetized participants. Data revealed 12 stage sequences among patient visits; dominant sequences differed according to patient category. An awake patient's average visit duration (2 hours 21 minutes) differed significantly from that of sedated (3 hours 38 minutes, P < .001) and anesthetized (4 hours 7 minutes, P < .001) patients; sedated and anesthetized visit durations did not differ significantly (P < .073), although this finding may be attributable to the small sample sizes. Variation in stage durations was also evident within and among patient types. Visit costs for sedated and anesthetized patients were 3.24 and 9.56 times higher, respectively, than those for awake patients. Costs for anesthetized patients were 2.95 times higher than those for sedated patients.

CONCLUSION

Visit durations were significantly longer for anesthetized and sedated patients. Anesthetized patients incurred the highest costs, followed by sedated patients.

Comparison of propofol versus propofol-ketamine combination for sedation during spinal anesthesia in children: randomized clinical trial of efficacy and safety

OBJECTIVES

This study was designed to compare the efficacy and safety of propofol vs propofol-ketamine combination for sedation during pediatric spinal anesthesia.

METHODS

Forty children, aged 3-8 undergoing spinal anesthesia for lower abdominal surgeries were included. Participants were randomly assigned into two groups. Group 1 received propofol bolus of 2 mg.kg(-1) followed by an infusion of 4 mg.kg(-1).h(-1). Group 2 received a combination of 1.6 mg.kg(-1) propofol and 0.4 mg.kg(-1) ketamine followed by an infusion of 3.2 mg.kg(-1).h(-1) and 0.8 mg.kg(-1).h(-1), respectively. The infusion rate was titrated to keep the child sedated at University of Michigan Sedation Score of 3. The heart rate, blood pressure, respiratory rate and oxygen saturation were recorded every 5 min. The episodes of spontaneous body movements and requirement of supplemental sedation were recorded. The postoperative recovery was assessed by modified Aldrette score.

RESULTS

Seventeen patients in group 1 and four patients in group 2 (P < 0.001) required extra boluses of study drug to prevent movements during lumbar puncture. Four patients experienced respiratory depression and three airway obstruction in group 1 when compared to one patient each in group 2 (P < 0.05). The recovery time was similar in both groups. None of the patient had postoperative nausea/vomiting or psychomimetic reactions.

CONCLUSIONS

Propofol-ketamine combination provided better quality of sedation with lesser complications than propofol alone and thus can be a good option for sedation during spinal anesthesia in children.

Sedation trends in the 21st century: the transition to dexmedetomidine for radiological imaging studies

Sedation for radiological imaging studies encompasses the majority of all sedation-related procedures outside of the intensive care unit. This review will follow the evolution of pediatric sedation for radiological imaging studies in North America as well as the transition of sedation services from the oversight of radiologists to those of other providers. The evolving options for sedation agents will be reviewed, with attention given to examining the advantages, limitations, and risks of replacing the standard sedatives with dexmedetomidine.

Sedation for emergent diagnostic imaging studies in pediatric patients

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Sedating the child with congenital heart disease

The number of pediatric patients requiring sedation for procedures performed outside the operating room environment continues to grow yearly, as does the number of patients surviving to adulthood with the residua and sequelae of congenital heart disease. Ongoing efforts to develop guidelines to enhance the safety of these pediatric sedative encounters have resulted in great strides in the prevention of adverse events. In addition, the Society for Pediatric Sedation, associated with the Pediatric Sedation Research Consortium, provides an important forum for practitioner education and the promotion of safe care for infants and children undergoing sedative experiences. Care of the subset of patients with congenital heart disease or pulmonary hypertension remains especially demanding. The additional safety challenges posed by remote locations make the highest level of vigilance essential when planning and performing sedation for these children.