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Intravenous Ketamine Sedation of Pediatric Patients in the Emergency Department
PEDIATRICS/ORIGINAL
CONTRIBUTION
Intravenous Ketamine Sedation of Pediatric Patients in the Emergency Department From the Department of Emergency Medicine, Albany Memorial Hospital, Albany, New York. Receivedfor publication March 25, 1996. Revision received August 16, 1996. Acceptedfor publication September 3, 1996. Copyright © by the American College of Emergency Physicians.
Robert J Dachs, MD Geerge M Innes, MD
Study objective: To determine efficacy, safety, recovery times, and parental satisfaction with IV ketamine sedation in pediatric patients requiring brief, painful procedures in the emergency department. Methods: Pediatric ED patients whom we found to require brief (<10 minutes), painful procedures were considered candidates for ketamine sedation. Each subject received 1.0 to 2.0 mg/kg IV ketamine, after which the necessary procedure was performed. Result: Thirty patients, ranging in age from 18 months to 8 years, were enrolled in the study. With the exception of one patient in whom ketamine was inadvertently given subcutaneously, all subjects given IV ketamine exhibited sedation adequate for the planned painful procedure within 2 minutes of ketamine administration. An initial bolus of 1.0 mg/kg required supplemental administration of ketamine in 50% of the patients (6 of 12), whereas an initial bolus of 1.5 mg/kg reliably produced adequate sedation in 94% (17 of 18). The median time elapsed before the criteria for discharge after injection were fulfilled was 25 minutes. No deleterious cardiopulmonary effects were noted. Vomiting and mild agitation after the procedure were observed in two and four cases, respectively. At follow-up all parents reported satisfaction with ketamine sedation. Conclusion: IV ketamine is a consistently effective method of producing a rapid, brief period of profound sedation and analgesia in children in the EB. Although no serious complications were noted in our series, larger studies are needed to establish this drug's safety profile in the ED. Vomiting, ataxia, and agitation were noted in a few cases. [Bachs RJ, Innes 6M: Intravenous ketamine sedation of pediatric patients in the emergency department. Ann EmergMedJanuary 1997;29:146-150.]
1 46
ANNALS OF EMERGENCY MEDICINE
29:1 JANUARY
1997
KETAMINE Dachs & Innes
!
INTRODUCTION
"Fhe appropriate relief of pain and anxiety is essential in the management of pediatric patients undergoing painful procedures in the emergency department. To accomplish this goal, a pharmacologic agent or combination of agents should provide ease of administration, rapid onset, effective and predictable analgesia; avoid airway and cardiopulmonary compromise; and result in rapid and smooth recovew.*,2 Ketamine hydrochloride is a unique pharmacologic agent that produces a trancefike catatonic state resulting in a reliable combination of sedation, amnesia, and analgesia. Spontaneous respiration, muscle tone of the tongue, and the cough and gag reflexes are preserved. Although ketamine has been shown to be safe and effective in more than 11,000 children, few studies on its use in the ED have been undertaken. 3 In 1990, Green and Johnson 4 reported data from 112 children sedated with IM ketamine in the ED. The average time required for recovery after one IM injection was 82 minutes, with a range of 30 to 175 minutes. Recovery from muhiple doses of ketamine required more than 2 hours. We have found these prolonged recovery times to be problematic. IV ketamine, on the other hand, produces a predictable onset of dissociation within 1 to 2 minutes of administration and is rapidly distributed into the peripheral tissues, with return of coherence in 15 to 20 minutes. In this study we sought to learn whether these pharmacokinetic properties would yield reliable, safe sedation in children requiring brief, painful procedures in the ED. We believe this study represents the first report on the use of IV ketamine in the ED. MATERIALS AND METHODS
This study was approved by the Institutional Review Board of Albany Memorial Hospital. Patients aged 3 months through 8 years whom we deemed to require immobilization for painful or emotionally disturbing procedures that were expected to be completed in 10 minutes or less were considered candidates for ketamme sedation. We excluded patients with acute or chronic pulmonary infection or cardiovascular disease, including hypertension; head injury associated with loss of consciousness, altered mental status, or emesis; central nervous system mass lesions, hydrocephalus, and other conditions associated with intracranial hypertension; glaucoma or acute globe injury; prior adverse reaction to ketamine; psychosis; thyroid disorder or use of thyroid medications; or porphyria; and any patient who had consumed a full meal in the 3 hours preceding presentation.
JII.NUARY 1997 2 9 : 1 ANNALS OF EMER6ENCY MEDICINE
Informed consent was obtained from all parents and guardians. We enrolled patients from May 21, 1995, through March 1, 1996. On the basis of previous recommendations in the literature 3,5, we chose to administer 1.0 mg/kg ketamine hydrochloride and to titrate additional doses as needed at the start of the study. On learning that 6 of the initial 11 children still withdrew from painful stimuli and thereby required supplemental dosing, we increased the ketamine dose to a 1.5 mg/kg initial bolus. With the exception of one patient who received the original dose (1,0 mg/kg), all of the remaining 19 patients received a 1.5-mg/kg initial dose. All doses were administered over a period of 30 to 60 seconds. One of us (RD) added atropine .01 mg/kg to each syringe containing ketamine, whereas the other (GI) did not use atropine. IV access was maintained throughout the procedure. Pulse, blood pressure, respiratory rate, and mental status were recorded every 5 minutes; and pulse oximetry was monitored continuously by the nursing staff during the procedure and until recovery was complete. The treating physician was responsible for recording all doses, IV access, efficacy, and duration of sedation; adverse events; and the point at which the patient met appropriate discharge criteria. These criteria comprised return to the presedation level of consciousness; verbalization appropriate for age; ability to recognize parents; and return of purposeful neuromuscular activity. Parents were warned that their children might experience unsteady gait or vomiting for several hours after discharge. We made follow-up telephone ca]ls within 2 to 6 days of discharge to all parents and guardians and queried them about the occurrence of delayed adverse events--in particular, vomiting, ataxia, and nightmares. They were also asked to rate the child's level of comfort during the procedure as very uncomfortable, uncomfortable, comfortable, or very comfortable. Finally, the parents were asked whether they were pleased that sedation was offered and whether, if their children were ever in the same situation, they would want ketamine sedation to be given again. RESULTS
Thirty children were enrolled in the study (age range, 18 months to 8 years; median, 38 months). Twenty-one were boys. Laceration repair was the most common procedure (27 of 30 [90%1).The remaining cases included removal of foreign bodies from feet and ears and lumbar puncture. Veins in the hands and antecubital regions were most often used for IV access (17 and 13 cases, respectively). In one case, IV access was believed to be present when the char-
147
KETAMINE
Dachs & Innes
acteristic "flash" of blood appeared in the tubing. However, extravasation of the drug resulted in subcutaneous administration, which caused partial and delayed sedation. No local or systemic adverse events occurred in this patient. The first 11 patients in this series were given an initial 1.0-mg/kg bolus of ketamine. Six of these patients (54%) required supplemental doses of .5 to 1.0 mg/kg before painful stimuli went unheeded. The remaining 19 patients, with one exception, each received an initial bolus of 1.5 mg/kg of ketamine; only one patient in this group (5.5%) required a supplemental dose Of .5 mg/kg for adequate sedation. Twenty-one patients also received atropine .01 mg/kg; in none did hypersalivation develop. One patient in the group of nine patients who did not receive atropine (11%) did experience hypersalivation. No airway compromise occurred in this patient, and intervention was not required. In all cases of IV administration of ketamine (with the exception of the child in whom the drug was administered subcutaneously), dissociative sedation developed within 2 minutes. Each child exhibited a characteristic wide-eyed, glassy stare with nystagmus. Withdrawal from painful stimuli ceased. Fourteen of the 27 patients undergoing laceration repair (52%) received local anesthesia. The decision to use local anesthesia was left to the treating physician; the most common reasons were to decrease bleeding (using lidocaine with epinephrine) and to provide prolonged local anesthesia. Two patients were noted to exhibit brief episodes of hypertonicity, and two others made brief random movements while sedated. This muscle activity was easily controlled by assistants, and no child required mechanical restraint. No deleterious cardiopulmonary effects were noted. Vital signs, recorded every 5 minutes, remained stable. Oxygen saturation remained greater than 93% in all patients, and no patient required supplemental oxygen. The median time from injection to fulfillment of recovery criteria before discharge was 25 minutes. Most children remained quiet during the recovery period in the ED; only four (13%) cried during recovery. One patient did vomit during the recovery period but did not require assistance in clearing the airway. Telephone follow-up was completed in all but one case (96.6%). All parents responded that they were pleased that sedation had been offered. When asked whether they would want their children to have ketamine sedation again in similar circumstances, all responded affirmatively. When asked to estimate their children's level of comfort during the procedure, 12 responded that they believed their children were very comfortable, 14 said they believed their children had been comfortable, and 1 responded that the child had been uncomfortable (in two cases, the parents did not remain at the bedside during the procedure). One
1 48
child vomited after arriving home. Nine parents reported postprocedure ataxia that persisted .5 to 2 hours. Most parents reported that their children slept on arriving home, and none reported nightmares. DISCUSSION
IV ketamine administration has many attractive pharmacokinetic properties that recommend it for sedation of children in the ED. A dose of 1 mg/kg has been reported to have resulted m a peak concentration and clinical effects within 1 minute. 6 In our study, a dose of 1.5 mg/kg reliably produced dissociative sedation within 2 minutes. After IV administration, ketamine is rapidly distributed into peripheral tissues, resulting in return of coherence within 15 minutes/We found that this property made it possible for our patients to fulfill established criteria for discharge roughly 25 minutes after ketamine administration. IM injection, on the other hand, has been shown to necessitate a length of stay nearly 1 hour longer. 4 Because close monitoring is required in both IV and IM injections, we found that the IV route was the more efficient method of sedation in these children. Without exception, the parents involved in this study were pleased with ketamine sedation. All responded that if they ever found themselves in a similar situation, they would want their children to receive ketamine sedation again. This affirmative response was obtained even in the cases in which minor difficulties occurred. The fact that every parent was also pleased that sedation was offered should encourage emergency physicians to consider offering some form of sedation in these cases. The much-publicized emergence reactions associated with ketamine were rare in our study. The four children who cried during the recovery period may have been experiencing emergence reactions. However, none of these children was reported to experience any sequelae. None of the children was reported to have had subsequent nightmares. One child, on awakening, noted that her mother had "three heads." Our results are consistent with the previous observation that 0% to 10% of children experience emergence reactions. 3 Although coadministration of a low dose of benzodiazepine can reduce this unpleasant reaction, we did not use these drugs because they can delay ketamine metabolism and prolong recovery s-l° Two children in our study (6.6%) vomited. This finding is consistent with previously reported rates ranging from 0% to 43%. Green and Johnson pooled data on 3,358 children from 35 reports and noted an 8.5% rate of emesis. 3 We recommend, if ketamine is to be used, that suction
ANNALS OF EMERGENCY MEDICINE
29:1 JANUARY 1997
KETAMINE
Dachs & Innes
equipment be available during the procedure and that administration be delayed in cases in which full meals were ingested 3 hours before the procedure. Ketamine-induced ataxia is a well-known phenomenon; we noted it in approximately one third of our patients. Parents must be warned about the possibility of disequilibrium and instructed to keep their children from walking independently during the postprocedure period. The principle of achieving adequate pain control with a high degree of safety has recently been extensively promoted. The Joint Commission on Accreditation of Healthcare Organizations, the Agency for Health Care Policy, the American Academy of Pediatrics, the American College of Emergency Physicians, and the American Nurses Association have all made this principle the cornerstone of their policies. 11-15 Ketamine has been reviewed extensively and shown to be extremely safe. A summary of 97 reports involving 17,550 administrations of ketamine, with at least 11,589 in pediatric patients, identified no major cardiovascular complications or deaths associated with ketamine administration. 3 Despite this remarkable safety record, appropriate monitoring and readiness for any potential respiratory or airway emergency is prudent; clinical aspiration and lary-ngospasm ]nave been reported on rare occasions. To our knowledge, only two cases of aspiration in nonneonates have been reported m the literature, one in an infant with a full stomach and the second in a 6-year-old with a brain tumor. 16,1z Both of these conditions are contraindications to ketamine administration. Cases of transient laryngospasm have been reported and are often associated with hypersalivation or active respiratory infection. 3 The former reaction can be inhibited
REFERENCES
Figure. Contraindications to the use of ketamine. 3,7 Age of 3 months or younger Active pulmonary infection or disease Procedures resulting in large amounts of oral secretions or blood History of airway instability, tracheal surgery, or tracheal stenosis Cardiovascular diseases in which a transient increase in blood pressure or pulse can be deleterious (eg, angina, heart failure, aneurysm, or uncontrolled hypertension) Conditions associated with intracranial hypertension (including central nervous system mass lesions, hydrocephalus, and head injuries associated with increased intracranial pressure) Glaucoma or acute globe injury Prior adverse reactions to ketamine Psychiatric illness Full meal within 3 hours of administration* *The use of ketamine is not recommendedin this situation; however, supporting literature evidence is limited.
JI~,NUARY 1997
by the concurrent administration of atropine .01 mg/kg, and the latter remains an absolute contraindication to ketamine administration. Fortunately, laryngospasm requiring airway intervention in healthy children is extraordinarily rare; only 2 children in more than 11,589 administrations have required intubation. ~s,19 Transient respiratory depression has also been reported in cases in which ketamine was intravenously administered over a period shorter than 10 seconds, 2°,2~ We followed the recommendation of most authorities that IV ketamme be given over a period of 30 to 60 seconds, and we witnessed no transient apnea or respiratory depression. Although these respiratory emergencies are rare and often avoidable, attention to contraindications to ketamine administration and appropriate monitoring is imperative. The contraindications to ketamine use are reviewed in the Figure. Monitoring--including pulse, respiratory rate, blood pressure, pulse oximetry, and mental status--should be followed until the child meets appropriate discharge criteria. Although this study is limited by its small sample size, it represents the first formal evaluation of IV ketamine administration in children in the ED. We found that ketamine administration was particularly helpful in lacerations located around the mouth and on the distal extremities, locations in which immobility is necessary and where topical analgesics (tetracaine-adrenaline-cocaine or other comparable preparations) are contraindicated. IV ketamine may be useful in other ED conditions requiring analgesia and immobilization, such as burn care and orthopedic reduction. We recommend that this method of sedation be further evaluated to determine its safety and applicability in other conditions and in other EDs.
29:1
ANNALS OF EMERGENCY MEDICINE
1. Yaster M, DeshpandeJK, Maxwell LG: The pharmacologic management of pain in children. ComprTher1989;15:14-26. 2. Terndrup TE: Pain control, analgesia, and sedation, in Barken RM (ed): PediatricEmergency Medicine: Conceptsand ClinicalPractice.St Louis: Mosby-Year Book, 1992:44-59. 3. Green SM, Johnson NE: Ketamine sedation for pediatric procedures.2. Review and implications. Ann EmergMed 1990;19:1033-1046. 4. Green SM, Nakamura R, Johnson NE: Ketamine sedation for pediatric procedures. I. A prospective series. Ann EmergMed 1990;19:1024-1032. 5. Beonett CR, Stewart RD: Ketamine hydrochloride, in Paris PM, Stewart RD (eds): Pain Managementin EmergencyMedicine. East Norwalk, Connecticut: Appleton & Lunge, 1988. 6. CorssenG, Hayward JR, Gunter JW: A new parenteral anesthesia for oral surgery. J OralSurg 1969,27:627~632. 7. Sacchetti A, SchafermeyerR, Gerardi M, et ah Pediatric analgesia and sedation. Ann Emerg Med 1994;23:237-250. 8. White PF,Way WL. TrevorAJ: Ketamine:Its pharmacologyand therapeutic uses.Anesthesiology 1982;56:119-136. 9. Reich DL, Silvay G: Ketamine: An update on the first ~enty five years of clinical experience. CanJ Anaesth 1989;36:186-197.
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KETAMINE Dachs & Innes
10. Lo JN, CummingJF: Interaction between sedative premedicantsand ketamine in man and in isolated perfused rat livers. Anesthesiology1975;43:307-312. 11. Joint Commissionon Accreditation of HealthcareOrganizations:Accreditation Manual for Hospitals. Chicago:JCAHO, 1995. 12. Acute Pain Management GuidelinePanel: Clinical Practice Guideline. Acute Pain Management: Operative or Medical Proceduresand Trauma.Washington DC: US Departmentof Health and Human Services,Public Health Service,Agencyfor Health Care Policyand Research, February1992, 13. AmericanAcademyof Pediatrics,Committeeon Drugs, Section of Anesthesiology:Guidelines for monitoring and managementof pediatric patients during and after sedation for diagnostic and therapeutic procedures.Pediatrics 1992;89:1110-1115.
Reprint no. 47/1/78154 Address for reprints:
Robert J Dachs, MD Department of Emergency Medicine Albany Memorial Hospital 600 Northern Boulevard Albany, New York 12204
14. Krauss BS, Shannon M, Damian FJ, et al: Guidelinesfor pediatric sedation. Dallas:American Collegeof EmergencyPhysicians,1995. 15. American NursesAssociation: Position Statement on the Role of the Registered Nurse in the Management of Patients Receiving IV ConsciousSedation for Short- Term Therapeutic, Diagnostic, or Surgical Procedures. 1991. 16. Sears BE: Complicationsof ketamine. Anesthesiology1971;35:231. 17. PenroseBH: Aspiration pneumonitisfollowing ketamine induction for general anesthesia. Anesth Analg 1972;51:41-43. 18. Faithfull NS, Haider R: Ketaminefor cardiac catheterization.Anaesthesia 1971;26:318-323. 19. SusmannDR: A comparativeevaluatien of ketamine anesthesiain children and adults. Anesthesiology 1974;40:459-464. 20. CorssenG, Miyasaka M, Domino EF: Changingconceptsin pain centrol during surgery: Dissociativeanesthesiawith CI-581.Anesth Analg 1969;47:746-759. 21. YoungRA, EpkerBN: Ketaminehydroch[oridein outpatient oral surgery in children. J Oral Surg 1971;29:703-705.
1 5o
ANNALS OF EMERGENCY MEDICINE
29:1
JANUARY 1997
CONTRIBUTION
Intravenous Ketamine Sedation of Pediatric Patients in the Emergency Department From the Department of Emergency Medicine, Albany Memorial Hospital, Albany, New York. Receivedfor publication March 25, 1996. Revision received August 16, 1996. Acceptedfor publication September 3, 1996. Copyright © by the American College of Emergency Physicians.
Robert J Dachs, MD Geerge M Innes, MD
Study objective: To determine efficacy, safety, recovery times, and parental satisfaction with IV ketamine sedation in pediatric patients requiring brief, painful procedures in the emergency department. Methods: Pediatric ED patients whom we found to require brief (<10 minutes), painful procedures were considered candidates for ketamine sedation. Each subject received 1.0 to 2.0 mg/kg IV ketamine, after which the necessary procedure was performed. Result: Thirty patients, ranging in age from 18 months to 8 years, were enrolled in the study. With the exception of one patient in whom ketamine was inadvertently given subcutaneously, all subjects given IV ketamine exhibited sedation adequate for the planned painful procedure within 2 minutes of ketamine administration. An initial bolus of 1.0 mg/kg required supplemental administration of ketamine in 50% of the patients (6 of 12), whereas an initial bolus of 1.5 mg/kg reliably produced adequate sedation in 94% (17 of 18). The median time elapsed before the criteria for discharge after injection were fulfilled was 25 minutes. No deleterious cardiopulmonary effects were noted. Vomiting and mild agitation after the procedure were observed in two and four cases, respectively. At follow-up all parents reported satisfaction with ketamine sedation. Conclusion: IV ketamine is a consistently effective method of producing a rapid, brief period of profound sedation and analgesia in children in the EB. Although no serious complications were noted in our series, larger studies are needed to establish this drug's safety profile in the ED. Vomiting, ataxia, and agitation were noted in a few cases. [Bachs RJ, Innes 6M: Intravenous ketamine sedation of pediatric patients in the emergency department. Ann EmergMedJanuary 1997;29:146-150.]
1 46
ANNALS OF EMERGENCY MEDICINE
29:1 JANUARY
1997
KETAMINE Dachs & Innes
!
INTRODUCTION
"Fhe appropriate relief of pain and anxiety is essential in the management of pediatric patients undergoing painful procedures in the emergency department. To accomplish this goal, a pharmacologic agent or combination of agents should provide ease of administration, rapid onset, effective and predictable analgesia; avoid airway and cardiopulmonary compromise; and result in rapid and smooth recovew.*,2 Ketamine hydrochloride is a unique pharmacologic agent that produces a trancefike catatonic state resulting in a reliable combination of sedation, amnesia, and analgesia. Spontaneous respiration, muscle tone of the tongue, and the cough and gag reflexes are preserved. Although ketamine has been shown to be safe and effective in more than 11,000 children, few studies on its use in the ED have been undertaken. 3 In 1990, Green and Johnson 4 reported data from 112 children sedated with IM ketamine in the ED. The average time required for recovery after one IM injection was 82 minutes, with a range of 30 to 175 minutes. Recovery from muhiple doses of ketamine required more than 2 hours. We have found these prolonged recovery times to be problematic. IV ketamine, on the other hand, produces a predictable onset of dissociation within 1 to 2 minutes of administration and is rapidly distributed into the peripheral tissues, with return of coherence in 15 to 20 minutes. In this study we sought to learn whether these pharmacokinetic properties would yield reliable, safe sedation in children requiring brief, painful procedures in the ED. We believe this study represents the first report on the use of IV ketamine in the ED. MATERIALS AND METHODS
This study was approved by the Institutional Review Board of Albany Memorial Hospital. Patients aged 3 months through 8 years whom we deemed to require immobilization for painful or emotionally disturbing procedures that were expected to be completed in 10 minutes or less were considered candidates for ketamme sedation. We excluded patients with acute or chronic pulmonary infection or cardiovascular disease, including hypertension; head injury associated with loss of consciousness, altered mental status, or emesis; central nervous system mass lesions, hydrocephalus, and other conditions associated with intracranial hypertension; glaucoma or acute globe injury; prior adverse reaction to ketamine; psychosis; thyroid disorder or use of thyroid medications; or porphyria; and any patient who had consumed a full meal in the 3 hours preceding presentation.
JII.NUARY 1997 2 9 : 1 ANNALS OF EMER6ENCY MEDICINE
Informed consent was obtained from all parents and guardians. We enrolled patients from May 21, 1995, through March 1, 1996. On the basis of previous recommendations in the literature 3,5, we chose to administer 1.0 mg/kg ketamine hydrochloride and to titrate additional doses as needed at the start of the study. On learning that 6 of the initial 11 children still withdrew from painful stimuli and thereby required supplemental dosing, we increased the ketamine dose to a 1.5 mg/kg initial bolus. With the exception of one patient who received the original dose (1,0 mg/kg), all of the remaining 19 patients received a 1.5-mg/kg initial dose. All doses were administered over a period of 30 to 60 seconds. One of us (RD) added atropine .01 mg/kg to each syringe containing ketamine, whereas the other (GI) did not use atropine. IV access was maintained throughout the procedure. Pulse, blood pressure, respiratory rate, and mental status were recorded every 5 minutes; and pulse oximetry was monitored continuously by the nursing staff during the procedure and until recovery was complete. The treating physician was responsible for recording all doses, IV access, efficacy, and duration of sedation; adverse events; and the point at which the patient met appropriate discharge criteria. These criteria comprised return to the presedation level of consciousness; verbalization appropriate for age; ability to recognize parents; and return of purposeful neuromuscular activity. Parents were warned that their children might experience unsteady gait or vomiting for several hours after discharge. We made follow-up telephone ca]ls within 2 to 6 days of discharge to all parents and guardians and queried them about the occurrence of delayed adverse events--in particular, vomiting, ataxia, and nightmares. They were also asked to rate the child's level of comfort during the procedure as very uncomfortable, uncomfortable, comfortable, or very comfortable. Finally, the parents were asked whether they were pleased that sedation was offered and whether, if their children were ever in the same situation, they would want ketamine sedation to be given again. RESULTS
Thirty children were enrolled in the study (age range, 18 months to 8 years; median, 38 months). Twenty-one were boys. Laceration repair was the most common procedure (27 of 30 [90%1).The remaining cases included removal of foreign bodies from feet and ears and lumbar puncture. Veins in the hands and antecubital regions were most often used for IV access (17 and 13 cases, respectively). In one case, IV access was believed to be present when the char-
147
KETAMINE
Dachs & Innes
acteristic "flash" of blood appeared in the tubing. However, extravasation of the drug resulted in subcutaneous administration, which caused partial and delayed sedation. No local or systemic adverse events occurred in this patient. The first 11 patients in this series were given an initial 1.0-mg/kg bolus of ketamine. Six of these patients (54%) required supplemental doses of .5 to 1.0 mg/kg before painful stimuli went unheeded. The remaining 19 patients, with one exception, each received an initial bolus of 1.5 mg/kg of ketamine; only one patient in this group (5.5%) required a supplemental dose Of .5 mg/kg for adequate sedation. Twenty-one patients also received atropine .01 mg/kg; in none did hypersalivation develop. One patient in the group of nine patients who did not receive atropine (11%) did experience hypersalivation. No airway compromise occurred in this patient, and intervention was not required. In all cases of IV administration of ketamine (with the exception of the child in whom the drug was administered subcutaneously), dissociative sedation developed within 2 minutes. Each child exhibited a characteristic wide-eyed, glassy stare with nystagmus. Withdrawal from painful stimuli ceased. Fourteen of the 27 patients undergoing laceration repair (52%) received local anesthesia. The decision to use local anesthesia was left to the treating physician; the most common reasons were to decrease bleeding (using lidocaine with epinephrine) and to provide prolonged local anesthesia. Two patients were noted to exhibit brief episodes of hypertonicity, and two others made brief random movements while sedated. This muscle activity was easily controlled by assistants, and no child required mechanical restraint. No deleterious cardiopulmonary effects were noted. Vital signs, recorded every 5 minutes, remained stable. Oxygen saturation remained greater than 93% in all patients, and no patient required supplemental oxygen. The median time from injection to fulfillment of recovery criteria before discharge was 25 minutes. Most children remained quiet during the recovery period in the ED; only four (13%) cried during recovery. One patient did vomit during the recovery period but did not require assistance in clearing the airway. Telephone follow-up was completed in all but one case (96.6%). All parents responded that they were pleased that sedation had been offered. When asked whether they would want their children to have ketamine sedation again in similar circumstances, all responded affirmatively. When asked to estimate their children's level of comfort during the procedure, 12 responded that they believed their children were very comfortable, 14 said they believed their children had been comfortable, and 1 responded that the child had been uncomfortable (in two cases, the parents did not remain at the bedside during the procedure). One
1 48
child vomited after arriving home. Nine parents reported postprocedure ataxia that persisted .5 to 2 hours. Most parents reported that their children slept on arriving home, and none reported nightmares. DISCUSSION
IV ketamine administration has many attractive pharmacokinetic properties that recommend it for sedation of children in the ED. A dose of 1 mg/kg has been reported to have resulted m a peak concentration and clinical effects within 1 minute. 6 In our study, a dose of 1.5 mg/kg reliably produced dissociative sedation within 2 minutes. After IV administration, ketamine is rapidly distributed into peripheral tissues, resulting in return of coherence within 15 minutes/We found that this property made it possible for our patients to fulfill established criteria for discharge roughly 25 minutes after ketamine administration. IM injection, on the other hand, has been shown to necessitate a length of stay nearly 1 hour longer. 4 Because close monitoring is required in both IV and IM injections, we found that the IV route was the more efficient method of sedation in these children. Without exception, the parents involved in this study were pleased with ketamine sedation. All responded that if they ever found themselves in a similar situation, they would want their children to receive ketamine sedation again. This affirmative response was obtained even in the cases in which minor difficulties occurred. The fact that every parent was also pleased that sedation was offered should encourage emergency physicians to consider offering some form of sedation in these cases. The much-publicized emergence reactions associated with ketamine were rare in our study. The four children who cried during the recovery period may have been experiencing emergence reactions. However, none of these children was reported to experience any sequelae. None of the children was reported to have had subsequent nightmares. One child, on awakening, noted that her mother had "three heads." Our results are consistent with the previous observation that 0% to 10% of children experience emergence reactions. 3 Although coadministration of a low dose of benzodiazepine can reduce this unpleasant reaction, we did not use these drugs because they can delay ketamine metabolism and prolong recovery s-l° Two children in our study (6.6%) vomited. This finding is consistent with previously reported rates ranging from 0% to 43%. Green and Johnson pooled data on 3,358 children from 35 reports and noted an 8.5% rate of emesis. 3 We recommend, if ketamine is to be used, that suction
ANNALS OF EMERGENCY MEDICINE
29:1 JANUARY 1997
KETAMINE
Dachs & Innes
equipment be available during the procedure and that administration be delayed in cases in which full meals were ingested 3 hours before the procedure. Ketamine-induced ataxia is a well-known phenomenon; we noted it in approximately one third of our patients. Parents must be warned about the possibility of disequilibrium and instructed to keep their children from walking independently during the postprocedure period. The principle of achieving adequate pain control with a high degree of safety has recently been extensively promoted. The Joint Commission on Accreditation of Healthcare Organizations, the Agency for Health Care Policy, the American Academy of Pediatrics, the American College of Emergency Physicians, and the American Nurses Association have all made this principle the cornerstone of their policies. 11-15 Ketamine has been reviewed extensively and shown to be extremely safe. A summary of 97 reports involving 17,550 administrations of ketamine, with at least 11,589 in pediatric patients, identified no major cardiovascular complications or deaths associated with ketamine administration. 3 Despite this remarkable safety record, appropriate monitoring and readiness for any potential respiratory or airway emergency is prudent; clinical aspiration and lary-ngospasm ]nave been reported on rare occasions. To our knowledge, only two cases of aspiration in nonneonates have been reported m the literature, one in an infant with a full stomach and the second in a 6-year-old with a brain tumor. 16,1z Both of these conditions are contraindications to ketamine administration. Cases of transient laryngospasm have been reported and are often associated with hypersalivation or active respiratory infection. 3 The former reaction can be inhibited
REFERENCES
Figure. Contraindications to the use of ketamine. 3,7 Age of 3 months or younger Active pulmonary infection or disease Procedures resulting in large amounts of oral secretions or blood History of airway instability, tracheal surgery, or tracheal stenosis Cardiovascular diseases in which a transient increase in blood pressure or pulse can be deleterious (eg, angina, heart failure, aneurysm, or uncontrolled hypertension) Conditions associated with intracranial hypertension (including central nervous system mass lesions, hydrocephalus, and head injuries associated with increased intracranial pressure) Glaucoma or acute globe injury Prior adverse reactions to ketamine Psychiatric illness Full meal within 3 hours of administration* *The use of ketamine is not recommendedin this situation; however, supporting literature evidence is limited.
JI~,NUARY 1997
by the concurrent administration of atropine .01 mg/kg, and the latter remains an absolute contraindication to ketamine administration. Fortunately, laryngospasm requiring airway intervention in healthy children is extraordinarily rare; only 2 children in more than 11,589 administrations have required intubation. ~s,19 Transient respiratory depression has also been reported in cases in which ketamine was intravenously administered over a period shorter than 10 seconds, 2°,2~ We followed the recommendation of most authorities that IV ketamme be given over a period of 30 to 60 seconds, and we witnessed no transient apnea or respiratory depression. Although these respiratory emergencies are rare and often avoidable, attention to contraindications to ketamine administration and appropriate monitoring is imperative. The contraindications to ketamine use are reviewed in the Figure. Monitoring--including pulse, respiratory rate, blood pressure, pulse oximetry, and mental status--should be followed until the child meets appropriate discharge criteria. Although this study is limited by its small sample size, it represents the first formal evaluation of IV ketamine administration in children in the ED. We found that ketamine administration was particularly helpful in lacerations located around the mouth and on the distal extremities, locations in which immobility is necessary and where topical analgesics (tetracaine-adrenaline-cocaine or other comparable preparations) are contraindicated. IV ketamine may be useful in other ED conditions requiring analgesia and immobilization, such as burn care and orthopedic reduction. We recommend that this method of sedation be further evaluated to determine its safety and applicability in other conditions and in other EDs.
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1. Yaster M, DeshpandeJK, Maxwell LG: The pharmacologic management of pain in children. ComprTher1989;15:14-26. 2. Terndrup TE: Pain control, analgesia, and sedation, in Barken RM (ed): PediatricEmergency Medicine: Conceptsand ClinicalPractice.St Louis: Mosby-Year Book, 1992:44-59. 3. Green SM, Johnson NE: Ketamine sedation for pediatric procedures.2. Review and implications. Ann EmergMed 1990;19:1033-1046. 4. Green SM, Nakamura R, Johnson NE: Ketamine sedation for pediatric procedures. I. A prospective series. Ann EmergMed 1990;19:1024-1032. 5. Beonett CR, Stewart RD: Ketamine hydrochloride, in Paris PM, Stewart RD (eds): Pain Managementin EmergencyMedicine. East Norwalk, Connecticut: Appleton & Lunge, 1988. 6. CorssenG, Hayward JR, Gunter JW: A new parenteral anesthesia for oral surgery. J OralSurg 1969,27:627~632. 7. Sacchetti A, SchafermeyerR, Gerardi M, et ah Pediatric analgesia and sedation. Ann Emerg Med 1994;23:237-250. 8. White PF,Way WL. TrevorAJ: Ketamine:Its pharmacologyand therapeutic uses.Anesthesiology 1982;56:119-136. 9. Reich DL, Silvay G: Ketamine: An update on the first ~enty five years of clinical experience. CanJ Anaesth 1989;36:186-197.
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10. Lo JN, CummingJF: Interaction between sedative premedicantsand ketamine in man and in isolated perfused rat livers. Anesthesiology1975;43:307-312. 11. Joint Commissionon Accreditation of HealthcareOrganizations:Accreditation Manual for Hospitals. Chicago:JCAHO, 1995. 12. Acute Pain Management GuidelinePanel: Clinical Practice Guideline. Acute Pain Management: Operative or Medical Proceduresand Trauma.Washington DC: US Departmentof Health and Human Services,Public Health Service,Agencyfor Health Care Policyand Research, February1992, 13. AmericanAcademyof Pediatrics,Committeeon Drugs, Section of Anesthesiology:Guidelines for monitoring and managementof pediatric patients during and after sedation for diagnostic and therapeutic procedures.Pediatrics 1992;89:1110-1115.
Reprint no. 47/1/78154 Address for reprints:
Robert J Dachs, MD Department of Emergency Medicine Albany Memorial Hospital 600 Northern Boulevard Albany, New York 12204
14. Krauss BS, Shannon M, Damian FJ, et al: Guidelinesfor pediatric sedation. Dallas:American Collegeof EmergencyPhysicians,1995. 15. American NursesAssociation: Position Statement on the Role of the Registered Nurse in the Management of Patients Receiving IV ConsciousSedation for Short- Term Therapeutic, Diagnostic, or Surgical Procedures. 1991. 16. Sears BE: Complicationsof ketamine. Anesthesiology1971;35:231. 17. PenroseBH: Aspiration pneumonitisfollowing ketamine induction for general anesthesia. Anesth Analg 1972;51:41-43. 18. Faithfull NS, Haider R: Ketaminefor cardiac catheterization.Anaesthesia 1971;26:318-323. 19. SusmannDR: A comparativeevaluatien of ketamine anesthesiain children and adults. Anesthesiology 1974;40:459-464. 20. CorssenG, Miyasaka M, Domino EF: Changingconceptsin pain centrol during surgery: Dissociativeanesthesiawith CI-581.Anesth Analg 1969;47:746-759. 21. YoungRA, EpkerBN: Ketaminehydroch[oridein outpatient oral surgery in children. J Oral Surg 1971;29:703-705.
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