Clinical Policy: Critical Issues in the Sedation of Pediatric Patients in the Emergency Department

Abstract

Other members of the EMSC Panel included:Ramon W. Johnson, MD (ACEP Board Liaison)Rhonda R. Whitson, RHIA (Clinical Policies Manager, ACEP)Tuei Doong (Vice President, The Nakamoto Group, Inc)Jenni Nakamoto-Yingling (President, The Nakamoto Group, Inc)Karen Belli (Public Policy and Partnerships Specialist, EMSC)Tasmeen Singh, MPH, NREMT-P (Executive Director, National Resource Center, EMSC)Tina Turgel (Nurse Consultant, EMSC)[Ann Emerg Med. 2008;51:378-399.]PrefaceEmergency physicians routinely provide sedation and analgesia, monitor the respiratory and cardiovascular status, and manage critically ill patients of all ages.1Innes G. Murphy M. Nijssen-Jordan C. et al.Procedural sedation and analgesia in the emergency department Canadian Consensus Guidelines.J Emerg Med. 1999; 17: 145-156Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar, 2American College of Emergency PhysiciansRapid sequence intubation.Ann Emerg Med. 1997; 29: 573PubMed Google Scholar, 3Glauser J. Mace S.E. Procedural sedation in the emergency department: regulations as promulgated by the Joint Commission on Accreditation of Healthcare Organizations and establishment of procedural sedation policy within the emergency department.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw-Hill, New York, NY2006: 15-21Google Scholar The provision of safe and effective sedation and analgesia is an integral part of emergency medicine practice and a component of the core curriculum for emergency medicine residency programs.4Core Content Task Force IIThe model of the clinical practice of emergency medicine.Ann Emerg Med. 2001; 37: 745-770Abstract Full Text Full Text PDF PubMed Google Scholar, 5Task Force on the Core Content for Emergency Medicine RevisionCore content for emergency medicine.Ann Emerg Med. 1997; 29: 792-811Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar, 6Hostetler M.A. Auinger P. Szilagyi P.G. Parenteral analgesic and sedative use among ED patients in the United States: combined results from the National Hospital Ambulatory Medical Care Survey (NHAMCS) 1992-1997.Am J Emerg Med. 2002; 20: 139-143Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar Failure to adequately treat a patient’s pain can have negative consequences, the event potentially affecting later physiologic responses and behaviors. Appropriately treating pain and anxiety decreases patient suffering, facilitates medical interventions, increases patient/family satisfaction, improves patient care, and may improve patient outcome.7American Academy of Pediatrics and American Pain SocietyThe assessment and management of acute pain in infants, children, and adolescents.Pediatrics. 2001; 108: 793-797Crossref PubMed Scopus (249) Google Scholar, 8Mace S.E. Murphy M. Pain management and procedural sedation: definitions and clinical emergency department management.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw Hill, New York, NY2006: 7-14Google Scholar, 9American Academy of Pediatrics and Canadian Paediatric SocietyPrevention and management of pain and stress in the neonate.Pediatrics. 2000; 105: 454-461Crossref PubMed Google Scholar, 10Anand K.J. Clinical importance of pain and stress in preterm neonates.Biol Neonate. 1998; 73: 1-9Crossref PubMed Scopus (231) Google ScholarProviding effective and safe procedural sedation in the emergency department (ED) is a multifactorial process beginning with the preprocedural patient assessment and continuing through intraprocedural monitoring and postprocedure evaluation. Setting up the proper environment and selecting the most appropriate pharmacologic and nonpharmacologic agents are keys to successful procedural sedation.1Innes G. Murphy M. Nijssen-Jordan C. et al.Procedural sedation and analgesia in the emergency department Canadian Consensus Guidelines.J Emerg Med. 1999; 17: 145-156Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar, 11Glauser J. Documentation and standard forms for use during procedural sedation in the emergency department.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw Hill, New York, NY2006: 22-30Google Scholar, 12Mace S.E. Barata I.A. Cravero J.P. et al.EMSC Grant Panel Writing Committee on Pharmacologic Agents Used in Pediatric Sedation and Analgesia in the Emergency Department Clinical policy: evidence-based approach to pharmacologic agents used in pediatric sedation and analgesia in the emergency department.Ann Emerg Med. 2004; 44: 342-377Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar, 13Zempsky W.T. Cravero J.P. American Academy of Pediatrics Committee on Pediatric Emergency Medicine and Section on Anesthesiology and Pain MedicineRelief of pain and anxiety in pediatric patients in emergency medical systems.Pediatrics. 2004; 114: 1348-1356Crossref PubMed Scopus (122) Google Scholar, 14Brown L. Minasyan L. Nonpharmacologic interventions.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw Hill, New York, NY2006: 398-403Google Scholar, 15Rogovik A.L. Goldman R.D. Hypnosis as treatment for pain.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw Hill, New York, NY2006: 390-397Google Scholar There are many drugs that can be used for procedural sedation and analgesia. In addition, there are various nonpharmacologic modalities that can be used for procedural sedation and analgesia.13Zempsky W.T. Cravero J.P. American Academy of Pediatrics Committee on Pediatric Emergency Medicine and Section on Anesthesiology and Pain MedicineRelief of pain and anxiety in pediatric patients in emergency medical systems.Pediatrics. 2004; 114: 1348-1356Crossref PubMed Scopus (122) Google Scholar, 14Brown L. Minasyan L. Nonpharmacologic interventions.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw Hill, New York, NY2006: 398-403Google Scholar, 15Rogovik A.L. Goldman R.D. Hypnosis as treatment for pain.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw Hill, New York, NY2006: 390-397Google Scholar The choice of a particular agent or modality is influenced by many factors.12Mace S.E. Barata I.A. Cravero J.P. et al.EMSC Grant Panel Writing Committee on Pharmacologic Agents Used in Pediatric Sedation and Analgesia in the Emergency Department Clinical policy: evidence-based approach to pharmacologic agents used in pediatric sedation and analgesia in the emergency department.Ann Emerg Med. 2004; 44: 342-377Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar These include patient characteristics (eg, age, comorbidity, special health care needs) and the procedure to be performed (painful or painless, duration, etc).12Mace S.E. Barata I.A. Cravero J.P. et al.EMSC Grant Panel Writing Committee on Pharmacologic Agents Used in Pediatric Sedation and Analgesia in the Emergency Department Clinical policy: evidence-based approach to pharmacologic agents used in pediatric sedation and analgesia in the emergency department.Ann Emerg Med. 2004; 44: 342-377Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar Appropriate monitoring and assessment are critical for safe and effective procedural sedation and analgesia.3Glauser J. Mace S.E. Procedural sedation in the emergency department: regulations as promulgated by the Joint Commission on Accreditation of Healthcare Organizations and establishment of procedural sedation policy within the emergency department.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw-Hill, New York, NY2006: 15-21Google Scholar, 11Glauser J. Documentation and standard forms for use during procedural sedation in the emergency department.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw Hill, New York, NY2006: 22-30Google Scholar, 16American College of Emergency PhysiciansClinical policy for procedural sedation and analgesia in the emergency department.Ann Emerg Med. 1998; 31: 663-677Abstract Full Text Full Text PDF PubMed Scopus (117) Google Scholar, 17Godwin S.A. Caro D.A. Wolf S.J. et al.American College of Emergency Physicians Subcommittee (Writing Committee) on Procedural Sedation and Analgesia in the Emergency DepartmentClinical policy: procedural sedation and analgesia in the emergency department.Ann Emerg Med. 2005; 45: 177-196Abstract Full Text Full Text PDF PubMed Scopus (138) Google ScholarA previous clinical policy focused on medications for achieving sedation and analgesia in pediatric patients undergoing procedures in the ED.12Mace S.E. Barata I.A. Cravero J.P. et al.EMSC Grant Panel Writing Committee on Pharmacologic Agents Used in Pediatric Sedation and Analgesia in the Emergency Department Clinical policy: evidence-based approach to pharmacologic agents used in pediatric sedation and analgesia in the emergency department.Ann Emerg Med. 2004; 44: 342-377Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar This clinical policy deals with 2 additional sedation drugs, nitrous oxide and chloral hydrate; a nonpharmacologic agent for sedation, sucrose; as well as preprocedural fasting or nulla per os (NPO) status, and discharge criteria.Multiple documents about procedural sedation have been issued by various professional organizations, including The Joint Commission, the American Academy of Pediatrics (AAP), the American Society of Anesthesiologists (ASA), and the American College of Emergency Physicians (ACEP).12Mace S.E. Barata I.A. Cravero J.P. et al.EMSC Grant Panel Writing Committee on Pharmacologic Agents Used in Pediatric Sedation and Analgesia in the Emergency Department Clinical policy: evidence-based approach to pharmacologic agents used in pediatric sedation and analgesia in the emergency department.Ann Emerg Med. 2004; 44: 342-377Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar, 16American College of Emergency PhysiciansClinical policy for procedural sedation and analgesia in the emergency department.Ann Emerg Med. 1998; 31: 663-677Abstract Full Text Full Text PDF PubMed Scopus (117) Google Scholar, 17Godwin S.A. Caro D.A. Wolf S.J. et al.American College of Emergency Physicians Subcommittee (Writing Committee) on Procedural Sedation and Analgesia in the Emergency DepartmentClinical policy: procedural sedation and analgesia in the emergency department.Ann Emerg Med. 2005; 45: 177-196Abstract Full Text Full Text PDF PubMed Scopus (138) Google Scholar, 18Joint Commission on Accreditation of Healthcare OrganizationsHospital Accreditation Standards.in: Joint Commission Resources, Inc, Oakbrook Terrrace, IL2004: 163-166Google Scholar, 19American Academy of PediatricsGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures.Pediatrics. 1992; 89: 1110-1115PubMed Google Scholar, 20American Academy of PediatricsGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: Addendum.Pediatrics. 2002; 110: 836-838Crossref PubMed Scopus (158) Google Scholar, 21American Society of AnesthesiologyPractice guidelines for sedation and analgesia by non-anesthesiologists.Anesthesiology. 1996; 84: 459-471Crossref PubMed Scopus (339) Google Scholar, 22American Society of Anesthesiology Task Force on Sedation and Analgesia by Non-AnesthesiologistsPractice guidelines for sedation and analgesia by non-anesthesiologists.Anesthesiology. 2002; 96: 1004-1017Crossref PubMed Scopus (700) Google ScholarThe goal of this panel is to eliminate the bias from the recommendations by creating a document that is, to the degree possible, evidence-based. With some aspects of procedural sedation, there is a relative deficiency of high-quality data.16American College of Emergency PhysiciansClinical policy for procedural sedation and analgesia in the emergency department.Ann Emerg Med. 1998; 31: 663-677Abstract Full Text Full Text PDF PubMed Scopus (117) Google Scholar This policy is not intended to set standards for individual institutions or practitioners and cannot address every topic about pediatric procedural sedation but does give data for answering key management issues using an evidence-based approach.IntroductionProcedural sedation is the technique of administering sedatives or dissociative agents with or without analgesics to induce a state that allows the patient to tolerate unpleasant procedures while maintaining cardiorespiratory function.16American College of Emergency PhysiciansClinical policy for procedural sedation and analgesia in the emergency department.Ann Emerg Med. 1998; 31: 663-677Abstract Full Text Full Text PDF PubMed Scopus (117) Google Scholar Analgesia is usually a component of procedural sedation particularly for painful procedures. Procedural sedation and analgesia yields a depressed level of consciousness while allowing the patient to maintain independent control of the airway and oxygenation by preserving the protective airway reflexes. Moderate sedation/analgesia, previously “conscious sedation,” is a drug-induced depression of consciousness during which patients respond purposefully to verbal or light tactile stimulation while maintaining protective airway reflexes.18Joint Commission on Accreditation of Healthcare OrganizationsHospital Accreditation Standards.in: Joint Commission Resources, Inc, Oakbrook Terrrace, IL2004: 163-166Google Scholar, 20American Academy of PediatricsGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: Addendum.Pediatrics. 2002; 110: 836-838Crossref PubMed Scopus (158) Google Scholar, 22American Society of Anesthesiology Task Force on Sedation and Analgesia by Non-AnesthesiologistsPractice guidelines for sedation and analgesia by non-anesthesiologists.Anesthesiology. 2002; 96: 1004-1017Crossref PubMed Scopus (700) Google Scholar Deep sedation/analgesia is a drug-induced depression of consciousness during which patients are not easily aroused, and may need airway and/or ventilatory assistance but may respond purposefully to repeated or painful stimulation.19American Academy of PediatricsGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures.Pediatrics. 1992; 89: 1110-1115PubMed Google Scholar, 20American Academy of PediatricsGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: Addendum.Pediatrics. 2002; 110: 836-838Crossref PubMed Scopus (158) Google Scholar, 22American Society of Anesthesiology Task Force on Sedation and Analgesia by Non-AnesthesiologistsPractice guidelines for sedation and analgesia by non-anesthesiologists.Anesthesiology. 2002; 96: 1004-1017Crossref PubMed Scopus (700) Google Scholar General anesthesia, in contrast, is a state of drug-induced loss of consciousness in which patients are not arousable and often have impaired cardiorespiratory function needing support.19American Academy of PediatricsGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures.Pediatrics. 1992; 89: 1110-1115PubMed Google Scholar, 20American Academy of PediatricsGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: Addendum.Pediatrics. 2002; 110: 836-838Crossref PubMed Scopus (158) Google Scholar, 22American Society of Anesthesiology Task Force on Sedation and Analgesia by Non-AnesthesiologistsPractice guidelines for sedation and analgesia by non-anesthesiologists.Anesthesiology. 2002; 96: 1004-1017Crossref PubMed Scopus (700) Google Scholar The terminology “moderate sedation,” “deep sedation,” and “general anesthesia” may not apply to dissociative sedation. In dissociative sedation, as with ketamine, a trancelike cataleptic state occurs with both profound analgesia and amnesia while maintaining protective airway reflexes, spontaneous respirations, and cardiopulmonary stability.23Green S.M. Krauss B. The semantics of ketamine.Ann Emerg Med. 2000; 36: 480-482PubMed Google Scholar In children, deep or dissociative sedation is usually required for painful procedures.24Cote C.J. Wilson S. Work Group on SedationGuidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: an update.Pediatrics. 2006; 118: 2587-2601Crossref PubMed Scopus (197) Google ScholarBecause individuals vary in their responses to a given dose of a specific sedative, practitioners providing procedural sedation and analgesia require the skills needed to provide airway/respiratory management and cardiovascular support. Health care providers administering procedural sedation/analgesia should be proficient in the skills needed to rescue a patient at a level greater than the desired level of sedation. Thus, if moderate sedation is desired, the practitioner should be able to provide the skills needed for deep sedation, and if deep sedation is intended, the practitioner should be competent in the airway management and cardiovascular support involved in general anesthesia.17Godwin S.A. Caro D.A. Wolf S.J. et al.American College of Emergency Physicians Subcommittee (Writing Committee) on Procedural Sedation and Analgesia in the Emergency DepartmentClinical policy: procedural sedation and analgesia in the emergency department.Ann Emerg Med. 2005; 45: 177-196Abstract Full Text Full Text PDF PubMed Scopus (138) Google Scholar Such skills are a requirement of emergency medicine training programs and an essential component of emergency medicine practice.3Glauser J. Mace S.E. Procedural sedation in the emergency department: regulations as promulgated by the Joint Commission on Accreditation of Healthcare Organizations and establishment of procedural sedation policy within the emergency department.in: Mace S.E. Ducharme J. Murphy M. Pain Management and Sedation: Emergency Department Management. McGraw-Hill, New York, NY2006: 15-21Google Scholar, 4Core Content Task Force IIThe model of the clinical practice of emergency medicine.Ann Emerg Med. 2001; 37: 745-770Abstract Full Text Full Text PDF PubMed Google Scholar, 5Task Force on the Core Content for Emergency Medicine RevisionCore content for emergency medicine.Ann Emerg Med. 1997; 29: 792-811Abstract Full Text Full Text PDF PubMed Scopus (28) Google ScholarMethodologyThis clinical policy was created after careful review and critical analysis of the medical literature. Multiple searches of MEDLINE and the Cochrane database were performed. Specific key words/phrases used in the searches are identified under each critical question. All searches were limited to English-language sources, human studies, and years 1976 to 2006. References obtained on the searches were reviewed by panel members (title and abstract) for relevance before inclusion in the pool of studies to be reviewed. Abstracts and articles were reviewed by panel members, and pertinent articles were selected. These articles were evaluated, and those addressing the questions considered in this document were chosen for grading. Additional articles were reviewed from the bibliographies of studies cited. Panel members also supplied articles from their own knowledge and files.The panel used the ACEP clinical policy development process; this policy is based on the existing literature; where literature was not available, consensus of panel members was used. The draft was sent to all of the participating organizations for comments during the expert review stage of development.All articles used in the formulation of this clinical policy were graded by at least 2 panel members for strength of evidence and classified by the panel members into 3 classes of evidence on the basis of the design of the study, with design 1 representing the strongest evidence and design 3 representing the weakest evidence for therapeutic, diagnostic, and prognostic clinical reports, respectively (Appendix A). Articles were then graded on 6 dimensions thought to be most relevant to the development of a clinical guideline: blinded versus nonblinded outcome assessment, blinded or randomized allocation, direct or indirect outcome measures (reliability and validity), biases (eg, selection, detection, transfer), external validity (ie, generalizability), and sufficient sample size. Articles received a final grade (Class I, II, III) on the basis of a predetermined formula taking into account design and quality of study (Appendix B). Articles with fatal flaws were given an “X” grade and not used in the creation of this policy. Evidence grading was done with respect to the specific data being extracted and the specific critical question being reviewed. Thus, the level of evidence for any one study may vary according to the question, and it is possible for a single article to receive different levels of grading as different critical questions are answered. Question-specific level of evidence grading may be found in the Evidentiary Table available online at http://www.annemergmed.com, and online at http://www.acep.org on the Clinical Policies page.Clinical findings and strength of recommendations regarding patient management were then made according to the following criteria:Level A recommendationsGenerally accepted principles for patient management that reflect a high degree of clinical certainty (ie, based on strength of evidence Class I or overwhelming evidence from strength of evidence Class II studies that directly address all of the issues).Level B recommendationsRecommendations for patient management that may identify a particular strategy or range of management strategies that reflect moderate clinical certainty (ie, based on strength of evidence Class II studies that directly address the issue, decision analysis that directly addresses the issue, or strong consensus of strength of evidence Class III studies).Level C recommendationsOther strategies for patient management that are based on preliminary, inconclusive, or conflicting evidence, or in the absence of any published literature, based on panel consensus.There are certain circumstances in which the recommendations stemming from a body of evidence should not be rated as highly as the individual studies on which they are based. Factors such as heterogeneity of results, uncertainty about effect magnitude and consequences, strength of prior beliefs, and publication bias, among others, might lead to such a downgrading of recommendations.This policy is not intended to be a complete manual on pediatric sedation issues but rather a focused examination of critical issues that have particular relevance to the current practice of emergency medicine.It is the goal of the panel to provide an evidence-based recommendation when the medical literature provides enough quality information to answer a critical question. When the medical literature does not contain enough quality information to answer a critical question, panel members believe that it is equally important to alert emergency physicians to this fact.Recommendations offered in this policy are not intended to represent the only diagnostic and management options that the emergency physician should consider. The panel clearly recognizes the importance of the individual physician’s judgment. Rather, this guideline defines for the physician those strategies for which medical literature exists to provide support for answers to the crucial questions addressed in this policy.Scope of ApplicationThis guideline is intended for physicians administering procedural sedation and analgesia to pediatric patients in hospital-based EDs.Inclusion CriteriaThis guideline applies to pediatric patients less than or equal to 18 years of age who are in a hospital ED and have conditions necessitating the alleviation of anxiety, pain, or both.Exclusion CriteriaThis guideline excludes patients greater than 18 years of age.Critical Questions1Should pediatric patients undergo a period of preprocedural fasting to decrease the incidence of clinically important complications during procedural sedation in the ED?Patient Management RecommendationsLevel A recommendationsNone specified.Level B recommendationsProcedural sedation may be safely administered to pediatric patients in the ED who have had recent oral intake.Level C recommendationsNone specified.Key words/phrases for literature searches: preprocedural fasting, NPO, gastric emptying agents, vomiting, aspiration, procedural sedation.Recommendations concerning preprocedural fasting in both pediatric and adult sedation are based on a rare but real risk of pulmonary aspiration. Definitive sedation guidelines based on sound evidence are lacking because of a paucity of ED studies about preprocedural fasting. The ASA fasting guidelines, adopted by the AAP, are consensus-based, extrapolated from patients undergoing general anesthesia.25American Society of Anesthesiologists Task Force on Preoperative FastingPractice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures.Anesthesiology. 1999; 90: 896-905Crossref PubMed Google Scholar As noted in these guidelines, “Published evidence is silent on the relationship between fasting times, gastric volume, or gastric acidity and the risk of emesis/reflux or pulmonary aspiration in humans.” Although these recommendations may be appropriately cautious when considering patients who are undergoing elective general anesthesia, controversy exists as to whether these guidelines are applicable to the pediatric ED population.An important distinction between procedural sedation and analgesia in the ED and general anesthesia in the operating room involves the preservation of airway reflexes. In moderate sedation, airway reflexes are generally maintained. These reflexes, although normally present, are less reliably maintained in deep sedation. However, in general anesthesia, airway reflexes are significantly blunted or completely suppressed, thus increasing the potential risk of aspiration.26Agrawal D. Manzi S.F. Gupta R. et al.Preprocedural fasting state and adverse events in children undergoing procedural sedation and analgesia in a pediatric emergency department.Ann Emerg Med. 2003; 42: 636-646Abstract Full Text Full Text PDF PubMed Scopus (91) Google Scholar, 27Warner M.A. Warner M.E. Weber J.G. Clinical significance of pulmonary aspiration during the perioperative period.Anesthesiology. 1993; 78: 56-62Crossref PubMed Google Scholar, 28Warner M.A. Warner M.E. Warner D.O. Perioperative pulmonary aspiration in infants and children.Anesthesiology. 1999; 90: 66-71Crossref PubMed Google Scholar, 29Borland L.M. Sereika S.M. Woelfel S.K. et al.Pulmonary aspiration in pediatric patients during general anesthesia: incidence and outcome.J Clin Anesth. 1998; 10: 95-102Abstract Full Text Full Text PDF PubMed Scopus (73) Google Scholar, 30Green S.M. Krauss B. Pulmonary aspiration risk during emergency department procedural sedation—an examination of the role of fasting and sedation depth.Acad Emerg Med. 2002; 9: 35-42PubMed Google Scholar Dissociative agents such as ketamine and inhalational agents such as nitrous oxide have a different mechanism of action and do not blunt the airway reflexes to the same degree as other sedatives. Therefore, the description for the continuum of sedation that ranges from anxiolysis to general anesthesia may not accurately reflect the minimal effect of these agents on protective airway mechanisms.Aspiration is a rare but well-documented associated risk in patients undergoing general anesthesia. The incidence of aspiration in pediatric patients has been reported to be 1:978 and 1:2,632 patients in 2 pediatric specific studies by Warner et al28Warner M.A. Warner M.E. Warner D.O. Perioperative pulmonary aspiration in infants and children.Anesthesiology. 1999; 90: 66-71Crossref PubMed Google Scholar and Borland et al.29Borland L.M. Sereika S.M. Woelfel S.K. et al.Pulmonary aspiration in pediatric patients during general anesthesia: incidence and outcome.J Clin Anesth. 1998; 10: 95-102Abstract Full Text Full Text PDF PubMed Scopus (73) Google Scholar When both emergent and elective patients of all ages are reviewed, the incidence decreases to less than 1:3,500.30Green S.M. Krauss B. Pulmonary aspiration risk during emergency department procedural sedation—an examination of the role of fasting and sedation depth.Acad Emerg Med. 2002; 9: 35-42PubMed Google Scholar, 31Mellin-Olsen J. Fasting S. Gisvold S.E. Routine preoperative gastric emptying is seldom indicated A study of 85,594 anaesthetics with special focus on aspiration pneumonia.Acta Anaesthesiol Scand. 1996; 40: 1184-1188Crossref PubMed Google Scholar, 32Engelhardt T. Webster N.R. Pulmonary aspiration of gastric contents in anaesthesia.Br J Anaesth. 1999; 83: 453-460Crossref PubMed Google Scholar During emergency surgery, the incidence of reported aspiration increases to 1:895 in adults and general population patients27Warner M.A. Warner M.E. Weber J.G. Clinical significance of pulmonary aspiration during the perioperative period.Anesthesiology. 1993; 78: 56-62Crossref PubMed Google Scholar and as frequent as 1:373 patients in the Warner et al pediatric study.28Warner M.A. Warner M.E. Warner D.O. Peri