Pediatric Procedural Sedation

Introduction

Procedural sedation and analgesia (PSA) is a rapidly evolving niche in pediatrics. In the past decade, everything from the name ("conscious sedation") to the drugs, practitioners, monitoring guidelines, and billing codes has evolved. Staying current is fundamental to staying safe and effective. This article will review recent Joint Commission on Accreditation of Healthcare Organizations (JCAHO) and American Academy of Pediatrics (AAP) guidelines, classic and recent literature, the most common medications, and controversies relating to procedural sedation.

History of Pediatric Procedural Sedation

The first AAP definitions were published in 1992, referring to "conscious sedation" as a depressed stated of consciousness where patients nonetheless were able to retain protective reflexes and "respond appropriately to stimuli." The American College of Emergency Physicians proposed new sedation terminology, noting that procedural sedation's goal is to medicate patients until they can tolerate unpleasant procedures -- an inappropriate response for a nonsedated person. Thus, the misnomer of "conscious" sedation was replaced with "moderate sedation." While using doses "not likely" to cause partial or complete loss of airway reflexes, unplanned descent to deeper sedation was acknowledged as an inherent possibility.^[1,2]

This spectrum of PSA as codified by the JCAHO and American Society of Anesthesiologists (ASA) describes 4 levels.^[3] When given "anxiolysis," a patient is expected to respond normally to verbal commands, albeit with impaired coordination and cognitive function. "Moderate sedation" most closely resembles deep relaxation, in which a person should respond purposefully to verbal or light stimuli, with adequate spontaneous ventilation and airway maintenance. Under "deep sedation," repeated painful stimulation should yield purposeful response, but this depth can impair the ability to maintain ventilatory function. "General anesthesia" is the state where a patient is not arousable, even with painful stimuli. The corresponding lack of tone can impair independent ventilatory function and protective airway reflexes.

The requirements for practitioner and monitoring are linked to the potential for airway compromise via the proxy of sedation level. As the field and experience with performing PSA grew, researchers questioned equating levels of patient responsiveness directly to absolute levels of risk. The dissociative hypnotic ketamine, for example, results in an unresponsive catatonic state while maintaining independent ventilatory function and exaggerating airway reflexes.^[4,5] Drs. Green and Krauss proposed dissociative sedation guidelines in 2004, but at present this is not reflected in accreditation sedation nomenclature.^[6,7]

Current Guidelines

JCAHO's 2006 requirements for moderate to deep sedation include that the licensed independent practitioner administering the medications be trained to manage rescue from one level deeper than anticipated.^[8] The patients must have a history and physical with an airway focus and must be immediately re-evaluated prior to administration of sedation. The practitioner must be immediately available to intervene after induction, and the patient must be continuously monitored and not discharged with a responsible adult until they meet pre-established criteria. Moreover, the standard of care for a given level of sedation should be the same no matter where in the hospital the sedation occurs. The details and interpretation of the above are left to individual hospitals.

New pediatric sedation monitoring guidelines from the AAP in 2006^[9] focus on the concept of preparedness to rescue from an unintended depth, while also highlighting patient discharge criteria and home care. Deep sedation requires an additional person whose sole responsibility is to monitor the patient, but the sedationist can perform a procedure under moderate sedation with a monitor who also assists. While supplemental oxygen is recommended, end tidal CO₂ monitoring is not expressly required. Smaller studies have found end tidal monitoring to be much more sensitive at detecting apnea but have been too small to show differences in patient outcomes.^[10] For example, Miner and colleagues^[11] reported that while pulse oximetry detected 11/33 patients with respiratory depression during procedural sedation, end tidal CO₂ identified them all. End tidal monitoring is essential when a patient cannot be directly observed, as in magnetic resonance imaging (MRI).

Precise methods of sedation monitoring are not specified, but the 1-6 Ramsay Score easily assesses sedation depth (Table 1).^[12]

Table 1. Ramsey Score

After sedation, discharge readiness can be evaluated with any number of scoring systems; the Aldrete Recovery Scale is a common one (Table 2).

Table 2. Aldrete Recovery Score

BP = blood pressure

Preceding the concept of rescue is knowing how to avoid a situation in which it would become necessary. While familiarity with the ASA Physical Class rating system (Table 3) is required, greater emphasis is now placed on airway evaluation, particularly as agreement on the ASA rating system may vary.^[13] The Mallampati score should be familiar to every sedationist.^[14] A child may not have an illness that affects their daily health, but this ASA categorization is less important than if their mouth is too small to be opened or you can't see their tonsils. Down syndrome, other macroglossia or micrognathia syndromes, and laryngomalacia complexes may not be captured by a scoring system but should typically involve consultation with a specialist before elective procedural sedation is considered.

Table 3. ASA Classification

BPD = blood pressure disease
Note: Sedate ASA class III patients with caution. ASA classifications are not precise in all circumstances.