Ketamine ======== þ Mercy Hospital Protocol for Ketamine þ Defeating Emergence Reactions: - "In verbal-age kids I have started using "psychological preparation" based upon an interesting study in which 0 of 90 adults experienced recovery reactions.* I tell kids up front that they will "dream" throughout their ketamine sedation, and that they should plan in advance what they want to dream about. Topics are typically puppies, ice cream, water-slides, etc." --Steve Green, MD - In adults prophylactic benzodiazepines have been shown to decrease the incidence & severity of unpleasant recovery reactions associated with ketamine.* This has not been shown in children, however, perhaps because clinically significant reactions are already quite rare in this age group. In both age groups benzos are reliably effective in treating such reactions if they should occur. *Coppel DL, et al: The taming of ketamine. Anaesthesia 1973; 28:293-296. - Effect of adding benzos: Concurrent benzodiazepines, antihistamines, or barbiturates compete with ketamine for hepatic degradation enzymes, and thus inhibit the latter drug's metabolism by 30 to 50% and prolong recovery time.* We are currently performing a study to determine how much. *Lo JN, Cumming JF: Interaction between sedative premedicants and ketamine in man and in isolated perfused rat livers. Anesthesiology 1975; 43:307-312. *Okamoto GU, Duperon DF, Jedrychowski JR: Clinical evaluation of the effects of ketamine sedation on pediatric dental patients. J Clin Pediatr Dent 1992;16(4):253-7. þ Main uses for ketamine: - sedating children for suturing etc. - intubating asthmatics - intubating patients in shock - anaesthesia in the backcountry or in disasters or developing nations. þ Ketamine characteristics: - Onset 1-2 minutes; dissociation and analgesia for 20-30 minutes; can usually discharge in 90 minutes. - give over 1-2 minutes. - Causes emergence reactions ("bad dreams") in some (? ~10% of mild reactions in the Green 1998 paper) but usually not severe and easily managed by a bit of Versed. - increased secretions especially in kids; often atropine added. - chest wall rigidity sometimes seen but rare - laryngospasm sometimes seen but rarely clinically significant. - Contraindications: + Age <6 mo. or > 10 years or wt < 5 kg. (for peds, but I use it all the time in adults --KC) + Pulmonary infection or disease (acute or chronic) (KC: except asthma) + Full meal within 2-3 hours of use + Cardiac disease or HTN + Head injury with LOC or altered mental status + CNS mass lesions, hydrocephalus, or intracranial hypertension + Glaucoma or acute globe injury + Psychosis + Thyroid disease + Porphyria + Prior adverse reaction to ketamine - works as bronchodilator: + causes catecholamine release + even if patient is beta-blocked, still causes bronchodilation by independent mechanism. þ Ketamine Dosage and Administration - source: Sewickley Valley Hospital policy 2/93 + Ketamine 2-4 mg/kg + atropine 0.01 mg/kg (min 0.1 mg, max 0.3 mg) in same syringe given IM - Alan D Clark at St. John's in Springfield, MO reports via emed-l good success with the lower (2 mg/kg) dose mixed without the Atropine, but adds 0.05 mg/kg of Versed, then he sutures at 12 minutes, when he sees nystagmus. - others say 1-2 mg/kg IV, 4-6 mg/kg IM. + repeat ketamine 2-4 mg/kg (without atropine) in 20 minutes if needed. - Discharge: + once normal level of consciousness + silly behaviour may persist for hours and not reason to delay discharge + NPO for 2 hours at home + no independent ambulation for 2 hours. - Hennepin's protocol drug mix: 1. Laceration repair - Complex (1-7 y.o.) Ketamine, IM (3 mg/kg) AND Atropine, IM (0.01 mg/kg, min. of 0.1 mg and max. of 0.3 mg) AND Midazolam, IM (0.1 mg/kg, max of 2mg) 2. Laceration repair - Oral (1-7 y.o.) Ketamine, IM (4 mg/kg) AND Atropine, IM (0.01 mg/kg, min. of 0.1 mg and max. of 0.3 mg) 3. Laceration repair - Oral (>7 y.o.) Ketamine, IM (2 mg/kg) AND Atropine, IM (0.01 mg/kg, min of 0.1 mg and max. of 0.3 mg) AND Midazolam, IM (0.1 mg/kg, max of 4 mg) (per Stephen Epstein, now at Beth Israel) - Dose is 4-6 mg/kg; use the higher concentration solution for IM injection. - Ready to intubate patient in 2-5 minutes. - Can use lower dose (2 mg/kg) and combine with one of the true paralytics below [Rotondo MF, et al. Urgent paralysis and intubation of trauma þ Ketamine Side Effect Profile þ Major Review: KETAMINE SEDATION FOR PEDIATRIC PROCEDURES: PART 1, A PROSPECTIVE SERIES Green, S.M., et al, Ann Emerg Med 19(9):1024, September 1990 This study, from Loma Linda University Medical Center in Loma Linda, CA, examined the use of ketamine sedation in 108 children requiring a painful and/or disturbing procedure in the ED. The children initially received a 4mg/kg IM dose of ketamine combined with atropine, 0.01mg/kg (up to 0.3mg) to reduce excessive salivation, with a repeat ketamine dose of 2-4mg/kg without atropine if sedation was insufficient ten minutes after the initial dose. The patients exhibited no clinically significant alterations in vital signs, blood pressure, pulse oximetry, or cardiac monitoring (when these monitoring modalities were employed). In 97% of the cases, acceptable conditions were achieved with a single dose of ketamine, and in the majority of cases performance of the procedure was possible within five minutes after administration. The mean recovery time was 82 minutes after a single dose of ketamine, and 121 minutes after two or more doses. One patient developed vomiting and unanticipated laryngospasm, but recovered uneventfully and did not require intubation. Six percent demonstrated vomiting well into the recovery phase. Postdischarge vomiting was reported for 7% of the children, and persistent disequilibrium that had resolved by six hours was reported for 31%. Only 5% of the parents indicated that they would prefer not to use ketamine for future procedures. The authors suggest that administration of IM ketamine by ED physicians in an appropriately monitored and equipped setting is an effective means of providing procedural sedation for children aged 12 months to 15 years. 51 references Copyright 1991 by Emergency Medical Abstracts - All Rights Reserved 1/91 - #28 KETAMINE SEDATION FOR PEDIATRIC PROCEDURES: PART 2, REVIEW AND IMPLICATIONS Green, S.M., et al, Ann Emerg Med 19(9):1033, September 1990 The author, from Loma Linda University Medical Center, reviews the use of ketamine for pediatric sedation. Ketamine induces a trancelike cataleptic state of "sensory isolation", and produces rapid and profound sedation and analgesia while maintaining spontaneous breathing and protective airway reflexes. Its safety has been noted in studies involving more than 11,000 children. Recovery times have ranged between 30 and 120 minutes. Peak concentrations are achieved within five minutes after IM injection, with dissociation typically persisting for 15-30 minutes. Ketamine stimulates salivary and tracheobronchial secretions. This effect may be minimized by concomitant administration of an anticholinergic agent such as atropine (0.01mg/kg, maximum total dose 0.5mg) or glycopyrrolate (0.005mg/kg, maximum total dose 0.25mg). Only 0.017% of children required intubation for airway complications in pooled data from 97 studies. Ketamine is contraindicated in patients aged three months or younger (and those with active respiratory infections), in whom the risk of airway complications is increased. Use of ketamine may be associated with emergence reactions, which may be minimized if excessive stimulation is avoided during recovery. Emesis, which generally occurs late during the recovery phase, has been reported in 8.5% of cases when data from 35 studies are pooled. Use of the IM route is advantageous in children requiring short procedures. A minimum dose of 4mg/kg IM has been reported to be required for consistent pediatric dissociation. In view of its safety and efficacy, the authors suggest increased use of ketamine (with proper precautionary measures and attention to contraindications) for pediatric procedures in the ED. More recent review: Green SM, Rothrock SG, Lynch EL, Ho M, Harris T, Hestdalen R, Hopkins GA, Garrett W, Westcott KIntramuscular ketamine for pediatric sedation in the emergency department: safety profile in 1,022 cases. Ann Emerg Med 1998 Jun;31(6):688-697 STUDY OBJECTIVE: To determine the safety of intramuscular ketamine when administered by emergency physicians for pediatric procedures in accordance with a defined protocol. METHODS: We assembled a consecutive case series of children aged 15 years or younger who were given ketamine in the emergency departments of a university medical center and an affiliated county hospital over a 9-year period. A protocol for ketamine use (4 mg/kg, intramuscularly) was followed. Treating physicians were instructed to complete data forms recording complications and adequacy of sedation concurrent with patient care. Subsequent chart review was used to determine indications, adjunctive drugs, time to discharge, and adverse reactions for all patients. RESULTS: Intramuscular ketamine was administered 1,022 times, mainly for laceration repair and fracture reduction. Physicians completed data forms for 431 of treated children (42%). Transient airway complications occurred in 1.4%: airway malalignment (n = 7), laryngospasm (n = 4), apnea (n = 2), and respiratory depression (n = 1). All were quickly identified and treated without intubation or sequelae. Emesis occurred in 6.7%, without evidence of aspiration. Mild recovery agitation occurred in 17.6%, moderate to severe agitation in 1.6%. No child required hospitalization for complications caused by ketamine. Ketamine produced acceptable sedation in 98% of patients. The median time from injection to emergency department discharge was 110 minutes for children given a single dose of ketamine. CONCLUSION: Intramuscular ketamine may be administered safely by emergency physicians to facilitate pediatric procedures in accordance with a defined protocol and with appropriate monitoring. Ketamine is highly effective, has a wide margin of safety, does not require intravenous access, and uniquely preserves protective airway reflexes.