On several occasions we have talked about the patient safety issues related to sedation for medical procedures in children (see our May 25, 2010 Patient Safety Tip of the Week “Propofol Issues”). The incidence of complications of pediatric procedural sedation varies by type of procedure, type of sedating agent, etc. One study (Larsen 2009) looked at the safety of propofol administration by pediatric intensivists for pediatric outpatient procedures in a single institution over a 6-year period. In over 4700 cases, major complications occurred in only 0.1% of cases, though minor complications were noted in 15% of cases. Another (Mallory et al 2010), using data from the Pediatric Sedation Research Consortium on over 25,000 pediatric patients (majority performed in radiology) documented airway and respiratory adverse events in 3.9% of cases of cases. Cases included two aspirations and one cardiac arrest but there were no deaths but in 2.4% of cases interventions beyond simple airway repositioning were required. Complications were more common in children less than 2 months, ASA class greater than 2, use of adjunctive opioids or midazolam, or adjunctive use of anticholinergics. In an ER setting (Pena 1999) pediatric procedural sedation was associated with a 2.3% incidence of adverse events, though none required hospitalization, intubation or pharmacological reversal.
Last month some terrific resources on procedural sedation for children became available. Though they are intended for those involved with care of children, most of the recommendations apply equally to adults.
NICE (UK’s National Institute for Health and Clinical Excellence) published a guideline on sedation for diagnostic and therapeutic procedures in children and young people (NICE 2010). And then a whole issue of Clinical Pediatric Emergency Medicine was devoted to the issue of procedural sedation in children.
The full NICE guideline contains 385 pages plus appendices but also has a useful quick reference guide and informational materials for patients and families. The full guideline has a comprehensive review of the literature and evidence base. It emphasizes that prodedural sedation is administered and monitored by a team and notes the training and skill needs of various team members for each level of sedation. It has particularly good sections on pre-procedure assessment and preparation (including the role of the parents). It also has good discussion on alternatives and adjuncts that may be used along with sedation. It breaks down recommendations for specific procedures (eg. painful ones, imaging, dental, endoscopy, etc.) and has some good algorithms and an excellent discussion of individual pharmacological agents used.
The Clinical Pediatric Emergency Medicine theme issue also has a nice article on the pharmacology of the agents commonly used in pediatric procedural sedation (Kost 2010) and one on choosing a regimen that fits the situation (Bennett 2010) with multiple case examples. For example, the regimen you might choose for sedation in a CT scan that does not hurt but could take as long as 45 minutes might be considerably different than one you’d use for reduction of an orthopedic injury that might be painful but brief. However, the article by Nagler and Krauss (Nagler 2010) on monitoring is probably the most useful. They discuss the historical evolution of guidelines for monitoring procedural sedation and provide comment on the current guidelines from the American Society of Anesthesiologists, the American Academy of Pediatrics, and the American College of Emergency Physicians. While the monitoring should be tailored to the specific pharmacologic agent being used for sedation, almost all those agents have respiratory risks necessitating close monitoring of parameters related to respiration, by both observational and mechanically recorded means. Some drugs, particularly propofol, may also have cardiovascular risks necessitating closer observation of cardiovascular parameters as well.
Nagler and Krauss note that central respiratory depression due to the sedating agents is not the only cause of respiratory complications. Obstructive apnea and laryngospasm may also occur with some agents and aspiration is always a risk. They have a nice discussion of how the capnographic waveform and respiratory rate monitoring may be helpful in quickly determining the cause of the respiratory problem and leading to the most appropriate intervention. They point out that direct clinical observation has traditionally been the cornerstone of monitoring during procedural sedation, observing respiratory rate and depth and skin color. But they note that continuous observation is almost impossible and therefore mechanical means of monitoring are critical. (You’ve also heard us say, on numerous occasions, that we are poor at predicting which patients have respiratory depression by just watching the patient. We have had medical students, residents, and attendings all observe patients on whom we had arterial blood gases and they did little better than chance at picking out which patients had respiratory depression.). They discuss the usefulness, as well as the limitations, of transthoracic impedance plethysmography, continuous pulse oximetry, capnorgaphy, EKG monitoring and noninvasive blood pressure monitoring and have a good discussion of future directions in monitoring procedural sedation. They also acknowledge the challenges that may occur in applying some of the monitoring tools in children who are uncooperative.
While providers often tailor their monitoring protocols to the intended level of sedation, in reality it is often impossible to predict the level of sedation that will be reached. Therefore, your monitoring must anticipate that the patient may well end up at a level of sedation deeper than had been planned.
The issue of use of oxygen during procedures is a complicated one. In several of our previous articles we have noted that oxygen treatment may actually cause a delay in recognition of respiratory depression. Nagler and Krauss acknowledge that risk but also note that pediatric patients are more vulnerable to precipitous onset of oxygen desaturation because they have a smaller residual capacity relative to total lung volume. Therefore, they recommend use of oxygen before and during procedures in children but recommend use of direct observation and capnography to watch for respiratory depression. Capnography becomes extremely important under such circumstances. A study (Deitch et al 2010) on procedural sedation in adults showed significantly fewer patients with hypoxia in the group monitored by capnography. The 17% absolute risk reduction translated to a number needed to treat (NNT) of 6 cases to prevent one episode of hypoxia. Capnography recognized 100% of the patients who developed hypoxia and did so a median time of 60 seconds before hypoxia developed. That delay meant the physicians usually had adequate time to intervene. We know of no comparable controlled trial in a pediatric population.
Monitoring does not end when the procedure is completed. Nagler and Krauss note that, although the vast majority of adverse events occur within 25 minutes of the last sedataion dose, nearly 10% occur after the procedure has ended. They therefore recommend the duration of monitoring be based on clinical and physiological parameters rather than the clock.
Assessment of readiness for discharge is critical in both adults and pediatrics. Nagler and Krauss note use of validated tools like the Vancouver Sedative Recovery Scale (McNab 1991) or the University of Michigan Sedation Scale (Malviya 2002) in determining readiness of discharge after procedural sedation. The NICE guideline recommends use of checklists to ensure that the child has returned to presedation state but also emphasizes that factors like caregiver readiness and travel distance should be considered.
The Mayo Clinic did a FMEA (Brice 2010) after a routine audit had disclosed several patients had not had their discharge assessment completed before they were discharged after MRI’s which required sedation. That problem apparently began after they had switched from a printed discharge form to an electronic form (yet another unintended consequence of technology!). During their FMEA they recognized that the printed form had served as a visual cue to nursing staff that the patient had been sedated and they needed to perform a formal assessment. One of the interventions they implemented was use of color-coded stickers and corresponding color-coded wristbands for patients to denote they had received sedation for MRI. Note that the issue of color-coded wristbands and bracelets has important implications (see our September 18, 2007 Patient Safety Tip of the Week “ ” and our October 2008 What’s New in the Patient Safety World “More on Color-Coded Wristbands”). In fact, the Mayo group initially chose hot pink wristbands but had to switch to a teal color when the Minnesota hospital group adopted a standardized set of colors for wristbands.
Note that adults and older children who may have driver’s licenses should always be accompanied by an adult who can drive them home after discharge. They should not be allowed to drive themselves. Many sites cancel and reschedule procedures when such patients show up for a procedure requiring sedation without being accompanied by such a driver.
In addition to the potential patient risks inherent in procedural sedation, you need to consider the potential financial and time costs involved and plan your case selection and workflows well. In our August 2010 What’s New in the Patient Safety World column “Sedation Costs for Pediatric MRI” we noted a Canadian study (Vanderby 2010) that addressed the financial impact of sedation for MRI scanning in pediatrics. They found that the average time spent in the MRI suite was 2 hours and 21 minutes for children scanned awake, 3 hours 38 minutes for those sedated, and 4 hours 7 minutes for those anesthetized. Corresponding average costs (in Canadian dollars) were $54.68, $177.27, and $522.73 respectively. This article has a good discsussion about workflow and personnel issues and has some good lessons learned that you may apply in your organization. Good reason to consider the appropriateness of the MRI scan in the first place!
Larsen R,Galloway D, Wadera S, et al. Safety of Propofol Sedation for Pediatric Outpatient Procedures. Clin Pediatr (Phila) 2009; 48: 819-823
Mallory MD, Baxter AL, Yanosky DJ, Cravero. JP. Use of Propofol for Sedation of Pediatric Patients by Emergency Physicians: A Report from the Pediatric Sedation Research Consortium (abstract). Pediatric Academic Societies meeting May 1, 2010
Pena BM, Krauss B. Adverse events of procedural sedation and analgesia in a pediatric emergency department. Ann Emerg Med 1999; 34: 483-91
NICE clinical guideline 112. Sedation in children and young people. Sedation for diagnostic and therapeutic procedures in children and young people. December 2010
NICE page with access to all materials
quick reference guide
Procedural Sedation in Children (theme issue). Clinical Pediatric Emergency Medicine 2010; 11(4): 231-306
Kost S, Roy A. Procedural Sedation and Analgesia in the Pediatric Emergency Department: A Review of Sedative Pharmacology. Clinical Pediatric Emergency Medicine 2010; 11(4): 233-243
Bennett J, DePiero A, Kost S. Tailoring Pediatric Procedural Sedation and Analgesia in the Emergency Department: Choosing a Regimen to Fit the Situation. Clinical Pediatric Emergency Medicine 2010; 11(4): 274-281
Nagler J, Krauss B. Monitoring the Procedural Sedation Patient: Optimal Constructs for Patient Safety. Clinical Pediatric Emergency Medicine 2010; 11(4): 251-264
Deitch K, Miner J, Chudnofsky CR, Dominici P, Latta P. Does End Tidal CO2 Monitoring During Emergency Department Procedural Sedation and Analgesia With Propofol Decrease the Incidence of Hypoxic Events? A Randomized, Controlled Trial. Annals of Emergency Medicine 2010; 55(3): 258-264
AJ Macnab AJ, Levine M, Glick N. et al. A research tool for measurement of recovery from sedation: The Vancouver Sedative Recovery Scale. Journal of Pediatric Surgery 1991; 26: 1263-1267
Malviya S, Voepel-Lewis T, Tait AR, et al. Depth of sedation in children undergoing computed tomography: validity and reliability of the University of Michigan Sedation Scale (UMSS). British Journal of Anaesthesia 2002; 88(2): 241-245
Brice J. Colored wristbands solve MR safety problem at Mayo Clinic. AuntMinnie.com January 17, 2011
Vanderby SA, Babyn PS, Carter MW, et al. Effect of Anesthesia and Sedation on Pediatric MR Imaging Patient Flow. Radiology 2010; 256(1): 229-237