Annual Meeting 2012 Review of Sessions
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Monday, May 21, 2012
Long-Term Effects of Repetitive Procedural Sedation
Reviewed by John Berkenbosch, MD
This presentation at the Seventh Annual Society for Pediatric Sedation Conference in Cleveland evaluated both the impact of sedation on post-encounter neurobehavioral changes and the impact of sedatives themselves on neurotoxicity and long-term developmental delay. This issue is of particular interest to the sedation provider today as the question of anesthetic neurotoxicity has become a key area of anesthesia research and implicates agents we commonly use in sedation. Due to the high profile of this topic, it will undoubtedly filter to the general public and we will be increasingly asked about it by families of children we sedate. Key points of the lecture were:
- that while evidence in the procedural sedation environment is limited, extrapolation from ICU and Anesthesia experiences strongly suggests that children who undergo sedated procedures are at significant risk of important post-encounter behavioral disturbances and
- that while evaluation of the direct neurotoxic effects of commonly used sedatives is ongoing and concerning, there is as yet insufficient data to recommend that current sedation practices be changed.
The initial part of the presentation focused on data demonstrating that children undergoing anesthesia commonly experience maladaptive behavioral changes in the short and medium term post-anesthesia periods. Risk factors for these behaviors include pre-encounter behavior disorders, pre-procedural parental anxiety, and the degree of post-encounter pain experienced. The section concluded with a review of some of the preparatory interventions that might be used to ameliorate these behaviors, including more family-centered preparation, increased patient/parent empowerment during the encounter, use of child life therapy, and pre-procedural amnestic agents (i.e. midazolam).
The latter part of the presentation summarized data relating to the direct neurotoxic effects of commonly used sedatives and anesthetics on the developing brain. Of concern to the sedation provider is that GABA agonists (including barbiturates, benzodiazepines, and propofol) and NMDA agonists (including ketamine and nitrous oxide) have been shown in rodent and primate models to have a direct toxic effect on synaptogenesis, brain development, and learning when administered during a critical “neurodevelopmental window”. Where this window lies in humans remains unclear and studies evaluating the impact of early anesthesia on development have revealed conflicting results. While some studies have found no correlation between anesthesia and development, others have reported that undergoing two or more anesthetics before the age of four years correlates with an increased risk of learning disabilities. Further confusing the issue is that while data are preliminary, animal studies have not found that dexmedetomidine has neurotoxic effect.
While these data are concerning and require our attention as sedation providers, they remain preliminary. Consequently, it would be premature to recommend changes to current sedation practices in terms of medication choices. However, as families become more aware of these concerns via the news media or their own research, it is important that we educate ourselves and our colleagues about this issue so that we may appropriately address their questions.
Research in Review
Reviewed by Janey Phelps, MD
Zier J, Liu M. Safety of high-concentration nitrous oxide by nasal mask for pediatric procedural sedation, experience with 7,802 cases. Pediatr Emer Care 2011;27:1107-1112.
This was a prospective observational study. It is the largest study of nitrous oxide administration for pediatric sedations with a total of 7802 encounters for 5,779 patients over a five and-a-half year period. The age range was 33 days old to 18 years old with a median age of five years. The children received N2O sedation/analgesia for diagnostic studies and/or therapeutic procedures. Children were excluded if nitrous oxide was contraindicated due to gas trapping for various clinical scenarios, pregnancy, altered level of consciousness, increased intracranial pressure or if a deeper level of sedation was indicated.
The standard procedure was to start at 60% nitrous oxide and titrate up or down according to the patient’s response. No adverse events were recorded for 95.7% of the cases. Minor adverse events included nausea at 1.6%, vomiting at 2.2%, and diaphoresis at 0.4%. Compared with patients with less than 15 minutes of nitrous oxide administration, patients with 15 to 30 minutes of administration were 4.2 times more likely to have an adverse event and patients who received the medication for >30 minutes were 4.9 times more likely to have an adverse event. There was no difference in adverse events if >/< 50% nitrous oxide was used, but it is important to note that the patients were grouped into >50% even if they only received >50% for a brief period during the administration of nitrous oxide. As such, only 700 patient encounters were with <50% nitrous oxide. Nine patients had potentially serious adverse events that included six with brief oxygen desaturation with one associated with “gagging” and one who had a tracheostomy and seemed to be related to increased tracheostomy secretions after the procedure. All of these cases improved back to baseline with interventions. Three developmentally appropriate patients developed brief <3 minute seizures, one of which occurred during nitrous oxide administration and two occurred while the patient was receiving 100% oxygen. One of these children had a known seizure disorder and one had previous activity suspicious for a seizure. All three events resolved and the patients returned to baseline and were discharged home on the same day.
Some of the limitations of the study include the potential for missing QA sheets, under-reporting of minor adverse events, missed events of apnea since capnography was not used, and recording of events was based on clinical observation alone, and use of a nasal mask which may have led to mixing with room air. This is the largest study to date examining adverse events associated with nitrous oxide in pediatric patients and it supports the notion that nitrous oxide can be safely administered at up to 70% by nasal mask for procedural sedation. This study indicates that it is best used for short procedures < 15 minutes duration since there is an increased rate of adverse events when used for >15 minutes.
Kannikeswaram N, Chen X, Sethuraman U. Utility of endtidal carbon dioxide monitoring in detection of hypoxia during sedation for brain magnetic resonance imaging in children with developmental disabilities. Pediatr Anesth 2011;21:1241-6.
This prospective observation study included 150 ASA 1-2 outpatient children age 1-10 years old with developmental disabilities who underwent procedural sedation for a brain MRI and levels of endtidal CO2, events of hypoxia, and other adverse events were recorded. Children were sedated according to the institution sedation policy which resulted in 94.7% of the children receiving pentobarbital at a mean dose of 4.58 mg/kg in incremental dosing starting with 3mg/kg bolus with or without fentanyl. The other sedation agents included chloral hydrate as an option for children less than three years old with a mean dose of 99.8 mg/kg. The study was powered based on a hypoxia rate of 15%. The hypoxia rate detected in this study was 18%. Significant endtidal CO2 abnormalities included a change in endtidal CO2 level >/=10mmHg from pre-sedation baseline, an intra-sedation >/= 50mmHg, and loss of capnography waveform. Endtidal CO2 abnormalities were noted in 42.6% of sedation encounters and of these patients, 70% of patients had documented changes in endtidal CO2 before hypoxia developed. Endtidal CO2 changes were noted a mean of 4.38 minutes prior to the occurrence of hypoxia. A significant limitation of this study is that there was no a comparison with developmentally normal children. The high rate of hypoxia may have been related to the sedation regimens.
Stump the Attending
Reviewed by Patricia (Trish) Scherrer, MD
As the final plenary session for Monday, Aaron Calhoun, MD, Mick Connors, MD, and Greg Hollman, MD participated in a panel discussion moderated by Trish Scherrer, MD. During this discussion, which included responses from our panel members as well as input from the audience, we reviewed some typical troublesome cases that can arise in a “day in the life” of a pediatric sedationist.
First, we discussed a child who traveled five hours for an elective MRI of the brain – with resolving URI symptoms and significant nasal congestion. Our panel members related that they had all found themselves in this situation, and that under the circumstances presented, they would likely proceed with caution and explanation of the associated risks to the family. A few folks would administer atropine or glycopyrrolate, but the concern of thickening the secretions was mentioned. We also discussed administration of nasal Afrin, which some panel and audience members do occasionally use.
Next, we reviewed the pros and cons of nitrous oxide administration for NG tube placement in a child with recurrent AML and abdominal pain who was, by exam or radiography, not felt to be obstructed. Although there was less familiarity with utilization of nitrous oxide in this circumstance, several of our audience members did agree with offering it as an option for this child. Providing deep sedation was not felt to be a safe option by our participants, with the caveat that, for the terminally ill child, the benefit of comfort might outweigh the attendant risks.
We briefly presented a situation where the sedationist is asked to perform the procedure, in this case a sedated LP for the neurology team. Everyone agreed that we should try and avoid this situation whenever possible. We also discussed a pediatric bronchoscopy scenario. Our panel members and most of our conference attendees do not provide procedural sedation for bronchoscopy. Those who do, typically utilize propofol.
Finally, we had a fantastic discussion around providing procedural sedation in a new remote location. Our panel experts reviewed personnel, equipment, and supply needs, and their likely preferences for induction and recovery in the sedation unit versus at the distant location (a new procedure site several floors away in the same hospital). Interestingly, participants from the panel and from the audience were split – some would induce and recover the patient in the sedation unit, transporting the sedated child. Some would evaluate the child in the sedation unit but would induce the child and allow the child to at least begin to awaken at the remote site before returning “home.”
Many thanks to our expert panel and our audience members – this was a superb interactive session, and we all enjoyed it immensely!
Tuesday, May 22, 2012
Oral Abstract Presentations
Successful Use of Dexmedetomidine for MRI Sedation in Autistic Children
Presented by Sheik Sohail Ahmed, MD
Reviewed by Michael Mazurek, MDAutism spectrum disorders represent a challenging group of neurodevelopmental disorders where those affected demonstrate difficult-to-control behavior, difficulty adjusting to changes, and frequent comorbid mental retardation. These patients are very challenging to sedate and there is no consensus on the best practice for providing procedural sedation to this group.
Dr. Ahmed presented his group’s work from Riley Hospital for Children in Indianapolis entitled “Successful Use of IV Dexmedetomidine for MRI Sedation in Autistic Children” during the poster discussion section. They retrospectively reviewed their MRI sedation using dexmedetomidine for autistic patients (n=40) and compared them to patients without autism (n=107). Their dexmedetomidine sedation regimen consisted of a 2 mcg/kg bolus over 10 minutes followed by a 1 mcg/kg/hr infusion titrated to a Ramsey score of four . They reported no sedation failures and no sedation complications. The autism patients required a larger bolus dose of dexmedetomidine to achieve sedation but a similar infusion dose to maintain sedation. Heart rates were lower and recovery times were longer in the autistic patients. They concluded that children with autism can be successfully sedated for MRI using dexmedetomidine.
Development of Quality and Safety Dashboard and Metrics for Pediatric Sedation
Presented by Cheri Landers, MD
Reviewed by Subhankar Bandyopadhyay, MDPerformance measurement in healthcare delivery ultimately helps to improve health for everyone in the United States. In 2005, the Institute of Medicine (IOM) published a report that stressed performance measure as an indicator of success of a healthcare organization. Measuring performance often leads to providing feedback both at the provider as well as at the system level, which ultimately leads to improvement. As healthcare delivery becomes more and more transparent to consumers, the goal now is to measure, report and improve at every level. These efforts help institutions to compare their data to national benchmarks while enabling themselves to become benchmarks in the process. Society of Pediatric sedation (SPS), with the collaboration of Pediatric Sedation Research Consortium (PSRC), is helping us to identify important and relevant quality metrics that can be major indicators of performance measures in our practice in pediatric sedation.
The fundamental concept in quality and performance measures mentioned in IOM reports is based on identification of six domains. They are safety, effectiveness, efficiency, timeliness, patient centeredness, and equity. This translates to our practice in pediatric sedation by providing right drugs in right dosages, to the right patient for the right procedure, through our understanding that sedation is a continuum, and as providers we should be able to “rescue” any patient when needed, that we practice evidence based medicine, that we provide timely and best care for our patients and families with explanations of what we do and why, and that we provide the same care irrespective of race, gender, ethnicity or geographic location. Although many publications came out of PSRC data analyses, PSRC database may not be equipped to capture all the quality domains as highlighted by the IOM, neither is this database able to capture the metrics needed to measure structure, process and outcome all together as theorized by Avedis Donabedian in his structural framework of quality. Cheri Landers, MD and her colleagues from Kentucky Children’s Hospital presented their work on developing quality and safety dashboard and metrics for pediatric sedation, a novel work in the area of pediatric sedation.
Dr. Landers presented their 2011 data with creation of this stop-light dashboard. Overall, system-wide quality indicators such as mortality, cardiac arrest, need for increased level of care and cancellation due to issues related to sedation are posted on this dashboard along with service, efficiency and safety domains. This dashboard gives an idea of where service is performed well and where opportunity for improvement exists. It is interesting to see how the efficiency metrics used by anesthesiologists were incorporated outside the operating room. This study should encourage other pediatric sedation services in other institutions to look at their own service line’s safety and efficiency and may be a precursor in developing quality metrics in often neglected areas in IOM quality domains such as equity and patient centeredness.One limitation of their work as stated by Dr. Landers herself was manual input of data. This creates room for human error and limits the real time utility of such dashboards. Incorporation of appropriate business intelligence tools for extraction and analysis of data from electronic medical records (EMR) may help to alleviate this rate- limiting step in the future.
* Not all sessions have been reviewed. Comments on sessions not reviewed here can be found throughout the newsletter.
