Ketamine Side Effect Profile ============================ þ IM Ketamine stridor easily managed without intubation - þ No way to tell who's going to get airway problems or emergence reactions [Green SM et al. Predictors of adverse events with intramuscular ketamine sedation. Ann Emerg Med 2000;35:35-42.] þ Ketamine Side Effects: emed-l discusssion - Harvey Louzon's Internet comments on Ketamine, for Kids, and regarding prophylactic treatment to prevent emergence phenomena: > Your notes about the incidence of laryngospasm are true enough but it > should be noted that laryngospasm associated with traditional general > anesthetics has an overall incidence of between 0.85% and 2.8% (1-3 mo olds > being at higher risk). I don't think we should scare people away from (or > perpetuate the anxiety about) ketamine. It is truly an ideal drug if used > properly. I agree with your suggestions except for the avoidance of oral > procedures. A dose of atropine (or robinul) and adequate suctioning of > secretions (without stimulating the posterior pharynx) should be enough to > keep the laryngospasm risk on par with other anesthetics (which is quite > low). By your statistics you can administer another 4999 dissociative > anesthetics without needed to grab a tube (so go for it!) Agreed. Although I wasn't trying to scare physicians from using it only looking at ways to make the proceedure even safer. Neverthless a 1 - 2% incidence of laryngospasm gives one pause to wonder. This is not something that is rare by any means. Be prepared for it. After using it safely for many years I should not have been surprised, ultimately, to see it myself. The number that we tend to remember is the 1 in 5000 incidence of laryngospasm requiring intubation. This translates to 1 in 50 to 1 in 100 instances of laryngospasm requiring intubation (assuming an incidence of 1% - 2%). So most of the time it will resolve of its own accord. Of course, when it does occur you don't know, at first, if it is 'one of those times.' H. Louzon MD J Trauma 1993; 34(2):242.] Pruitt et. al. Intramuscular ketamine, midazolam, and glycopyrrolate for pediatric sedation in the emergency department. J Oral Maxillofac Surg 1995 53(1):13-7. They used an IM dose of 3 mg/kg ketamine with 0.05 mg/kg versed and 0.005 mg/kg glycopyrrolate. Onset of action was about 6 minutes and duration of effect was about 30 minutes. Patients were given an additional 1 mg/kg dose of ketamine if needed. A recent placebo controlled study of ketamine using an oral dose of 10 mg/kg has been published: Qureshi et. al. Efficacy of oral ketamine for providing sedation and analgesia to children requiring laceration repair. Pediatr Emerg Care 1995 11(2):93-7 Norreslet J; Propofol infusion for sedation of children. Crit Care Med 18:890-92, 1990 3 case studies. Bloomfield EL, Masaryk TJ, Schubert A: Pediatric sedation for MRI of the brain and spine: a comparative study of pentobarbital vs. propofol.Anesth Analg 76:S22, 1993 Bready R, Spear R, Fisher B, et al: Propofol infusion: dose response for CT scans in children. Anesth Analg 74:S36, 1992 Lefever EB, Potter PS, Seeley NR ; Propofol sedation for pediatric MRI. Anesth Analg 76:919-920, 1993 Valtonen M: Anaesthesia for computerised tomography of the brain in children: a comparison of propofol and thiopentone.Acta Anaesthesiol Scand 33:170-173,1989 Hannallah R, Friedfeld S, Verghese P, et al: Comparison of propofol and thiopental for rapid anesthesia induction in infants.AnesthAnalg 74:S132, 1992 Hannallah RS, Baker SB, Casey W, et al: Propofol: Effective dose and induction characteristics in unpremedicated children. Anesthesiology 74: 217-219, 1991 Patel DK, Keeling PA, Newman GB, et al: Induction dose of propofol in children: Anaesthesia 43:949-952, 1988 Westrin P: The induction dose of propofol in infants 1-6 months of age and in children 10-16 years of age. Anesthesiology 74:455-458, 1991 Valtonen M, Lisalo E, Kanto J, et al: Propofol as an induction agent in children: Pain on injection and pharmacokinetics. Acta Anaesthesiol Scand 33:152-155, 1989 Swanson ER, Seaberg DC et al: Propofol for conscious sedation: A case series. Letter to editor; Academic Emerg Med Vol2, No7, 661-3, 1995 Swanson ER, Seaberg DC; Use of Propfol for conscious sedation in the Emergency Department. Abstract in Academic Emerg Med. Vol 2/No 5, 1995 Ross H, Plummer D; Propofol in the ED. Abstract in Academic Emerg Med. Vol 2/No 5, 1995 BTW, the reference below contains American guidelines that excuse you from having IV access for "conscious sedation" (defined as "minimally depressed level of consciousness that retains....ability (to) respond appropriately to physical stimulation and/or verbal command") For anything more (deep sedation and general anaesthesia), IV access is considered mandatory. (Generally I aim for sedation that is more deep than light!) Committee on Drugs, Section on Anesthesiology: Guidelines for the elective use of conscious sedation, deep sedation, and general anaesthesia in ped iatric patients: Pediatrics 1985: 72 (2);317-321. BTW, If there is anything more recent than this, can someone please send me a note? Ketamine for Kids ================= I use ketamine for complex facial or nailbed injuries in children. The head and distal extremities are difficult to adquately immobilize during a proceedure. A recent study (1) looked at the use of a combination of ketamine, midazolam and glycopyrrolate. The meds were mixed in the same syringe and given IM in the following dosage: ketamine 3 mg/kg, midazolam 0.05 mg/kg and glycopyrrolate 0.005 mg/kg. (The authors used glycopyrrolate because of some theoretical advantages over atropine that have never been conclusively proven. Most people use atropine 0.01 mg/kg instead). A second injection of ketamine 1 mg/kg was administered after 10 minutes if sedation was inadaquate. This cocktail was supplemented with local lidocaine anesthesia. The children ranged in age from 12 months to 7 years. Anesthesia was adaquate to begin the procedure after an average of 4.8 minutes (range 3 - 10 min). Two episodes of vomiting occured. O2 sats never dropped below 96% in any patient. The time from initial injection until discharge averaged 76 minutes (50 -120 min). Other than vomiting, side effects noted included a subtle (transient) diffuse hyperemic rash in 13.5% which faded upon awakening. (The first time I saw this I was at a loss to explain it), mild tachycardia (18% increase), and a few cases of hypertonicity and random movements. The authors adhered to a standard set of exclusion criteria such as age less than 1 year, possible increased ICP, cardiovascular disease, psychiatric illness and URI. I would make the following observations based upon the experience I have acquired using it. 1) Avoid using it in patients with URI. Because it results in increased laryngeal reflexes there is some concern about laryngospasm (incidence in a review of 12000 children: 0.017%). There is also some concern about using it for intra-oral injuries for the same reason but I have done so occasionally. 2) Prepare the parents for the procedure since they are sometimes disturbed when they see their child with eyes wide open in a catatonic state and worry about the sometimes prolonged recovery phase with random crying etc. 3) Supplement the procedure with local anesthesia. Just in case there is partial awakening during a long procedure. 4) Use no more than 0.01 mg/kg atropine as premedication. I have found that larger doses result in an excessive tachycardia when superimposed upon that produced by the ketamine itself. The use of an anticholinergic agent is important to offset the increased (upper and lower) airway secretions that it causes. 5) The rationale behind using midazolam in the prevention of emergence (uncommon but not unheard of below the age of 10) is well founded. There are several other reasons why benzos are the ideal premedication in this setting 1) it counteracts the muscular hypertonicity of ketamine 2) and it provides additional sedation. 6) In spite of adaquate sedation, random limb movements may occur and restraint may still be needed. 7) I have been accustomed to using ketamine IV but I have found that, although, it provides a profound degree of anesthesia it's short duration (20 min) may make the IM route preferable. 8) When given IV you will observe the presence of nystagmus in about 1 minute (5 or more after IM administration). This is a good sign that the child is well 'under the influence'. 9) Although ketamine genrally increases heart rate and BP it is a mycardial depressant and may (rarely) cause hypotension if the sympatho-adrenal system is already maximally stimulated. 10) Generally, with the exception of rare episodes of laryngospam, ventilations remain adaquate and protective airway reflexes are preserved. Nevertheless ventilatory responses to CO2 are impaired (there we go again) and high doses have been associated with hypoventilation. 11) Not merely a sedative as consciousness is profoundly impaired but, then again, not strictly a general anesthetic as airway reflexes are preserved. All in all, a potent drug with a wide safety margin and relatively rare serious side effects. H. Louzon MD (1) Pruitt et. al. Intramuscular Ketamine, Midazolam and Glycopyrrolate for Pediatric Sedation in the Emeregency Department. J Oral Max Surg 1995;53:13-17 Good Review =========== Green SM, Johnson NE Ketamine sedation for pediatric procedures: Part 2, Review and implications. Department of Emergency Medicine, Riverside General Hospital, California 92503. Ann Emerg Med 1990 Sep;19(9):1033-46 Article Number: UI90365310 ABSTRACT: Ketamine produces rapid and consistent pediatric sedation with a predictable onset and recovery time. A wide margin of safety is afforded without the respiratory and cardiovascular depression commonly seen with alternative agents. The efficacy of ketamine is well established in anesthesia and dentistry and has extensive applications in other specialties. Ketamine sedation facilitates superior technical and cosmetic results while minimizing emotional trauma to distraught children. The much-feared complications of aspiration and laryngospasm are extremely rare when ketamine is used with proper precautions. Ketamine deserves increased use in the ED, and we advocate additional clinical investigation in this setting. Ketamine: Prophylactice Medication for Emergence Phenomena =========================================================== I said: >Let me point out that I have never used ketamine in adults without first >premedicating them with a benzodiazepine. I think that is an essential >step and more and more I am doing this even in children.... Daniel Joyce then commented: >>I have a different understanding. The need for a benzodiazepine with >>ketamine administration is to attenuate and/or eliminate emergence >>phenomena. Thus, benzo serum levels are needed at time of >> emergence or awakening, not as a premedication nor while >> anesthetized with ketamine. I agree with Dan. James Li observed: >>>On a slightly different note, there was a fairly extensive discussion of >>>ketamine sedation in early 1994 on the list during which it was pointed >>>out that benzos are not magic in preventing emergence phenomenon. In the >>>overseas literature where ketamine of necessity is often used as primary >>>anesthesia, it has been pointed out that benzos are inferior to >>>promethazine for reducing emergence reactions, and that most such >>>reactions are handled equally well by placing the patient in a quiet >>>darkened room with familiar family members. This is sometimes impossible >>>in a busy western ED, but the point, I believe, is that there are several >>>ways of managing emergence. I really didn't think that there was any serious dispute over the superiority of benzodiazepines in preventing emergence reactions in adults. Had I been aware of this, I would have tried to muddy up the waters far sooner. With respect to Daniel's comments about the need for benzos at the time of emergence rather than as premedication I would make the following observations: When given intravenously, ketamine has a very short duration of action (20 minutes or so). I would assume that 'emergence' occurs as soon as drug effects start to wear off which is far sooner than the 60 - 90 minute period of lethargy that follows. Furthermore, I believe that vivid (and sometimes terrifying) dreams occur with the _onset_of_induction_ and not only as an 'emergence' phenomnon. One study implied the necessity of having benzos on board _at_the_time_of_induction to be fully effective (1). I think that it is a mistake to rely upon the _subsequent_ use of benzos to induce retrograde amnesia. A previous article that I had referenced indicated that benzos were more effective in inducing _antegrade_ then they were at _retrograde_ amnesia. As far as the superiority of benzos for preventing emergence phenonenon I would make the following observations: Diazepam is better than placebo (1). Midazolam is better than diazepam (3,5). Lorazepam is better than phenothiazines (4). I found one reference to the use promethazine from 1982 in the oral surgery literature. Please let me point out (James) that if you truly feel that promethazine is a superior drug for preventing emergence, (the main side effect of ketamine in adults who do not have a contraindication to it's use) then you should feel obligated to use it. I agree with your observation that several other considerations are important when using ketamine. Avoiding it's use in patients with psychiatric disorders, minimizing stimulation during the emergence process, etc. Perhaps you might consider the use of music (6) to ease the emergence process. I would recommend staying away from 'heavy metal', however. H. Louzon MD (1) Mattila MA, Larni HM, Nummi SE, Pekkola PO Effect of diazepam on emergence from ketamine anaesthesia. A double-blind study. Anaesthesist 1979 Jan;28(1):20-3 ABSTRACT: The series comprises 109 healthy females aged 14-49 years (mean age 28 years) hospitalized for legal abortion or diagnostic curettage. The patients were premedicated with morphine-scopolamine 0.4-0.7 ml i.m. (morphine 20 mg/ml, scopolamine 0.6 mg/ml) and atropine 0.01 mg/kg i.v. Ketamine 1.5 mg/kg was administered i.v. and immediately thereafter 2 ml of a coded solution i.v. consisting either of diazepam 10 mg or its solvent only. Supplementary doses of ketamine 0.2-0.4 mg/kg were administered when needed. Diazepam reduced the incidence of unpleasant dreams and experiences to a significant degree (p less than 0.01) according to the postanaesthetic interviews of the patients. Nausea occurred in the diazepam group in 2 per cent and in the placebo group in 17 per cent (p less than 0.01). In respect to the differences in opinion presented in literature the authors consider the time of administration of diazepam at induction to be of decisive importance and find prophylactic prevention of dreams justified as it cannot be predicted which of the patients will have unpleasant or even terrifying dreams. Dreams and/or experiences or their memories must be prevented at the stage at which the effect of ketamine commences. The authors do not, however, recommend ketamine anaesthesia for young adults, even when supplemented with diazepam. On the other hand, the authors consider the positive observations made during the study to be applicable to all other ketamine anaesthesias. (2) Toft P, Romer U Comparison of midazolam and diazepam to supplement total intravenous anaesthesia with ketamine for endoscopy. Can J Anaesth 1987 Sep;34(5):466-9 ABSTRACT: Fifty patients undergoing endoscopy (laryngoscopy, bronchoscopy, mediastinoscopy) were anaesthetised in a double-blind prospective trial using total intravenous anaesthesia. Half of the patients were anaesthetised with an infusion of a solution of 250 mg ketamine and 12.5 mg midazolam. The other patients received an infusion of a solution of 250 mg ketamine and 20 mg diazepam. In addition, both groups were given increments of 50-100 micrograms of fentanyl. The immediate awakening time (t1) was not significantly different between groups, but the patients who had received midazolam-ketamine, had a significantly shorter time to more complete recovery (t2), a significantly lower frequency of emergence reactions and were more satisfied with the anaesthetic than the patients who had received diazepam-ketamine. There was no difference between groups with respect to intraoperative heart rate and blood pressure. No awareness during anaesthesia was reported. (4) Lilburn JK, Dundee JW, Nair SG, Fee JP, Johnston HM Ketamine sequelae. Evaluation of the ability of various premedicants to attenuate its psychic actions. Anaesthesia 1978 Apr;33(4):307-11 ABSTRACT: The ability of a number of drugs to abolish the emergence delirium and unpleasant dreams which follow anaesthesia induced with 2 mg/kg ketamine was studied. These included three benzodiazepines, droperidol and 'neurolept' combinations and four commonly-used premedicants. When given intravenously 10 min before induction of anaesthesia flunitrazepam and lorazepam gave best results. In a subsequent study, these two benzodiazepines and diazepam were given intravenously 30-40 min before induction of anaesthesia. There was no doubt that 4 mg lorazepam gave the greatest protection and is worthy of further study in this respect. (5) Cartwright PD Pingel SM Midazolam and diazepam in ketamine anaesthesia. Anaesthesia (1984 May) 39(5):439-42 Midazolam 0.07 mg/kg was compared with diazepam 0.12 mg/kg intravenously as an adjuvant to ketamine anaesthesia in healthy patients undergoing minor gynaecological operations of less than 15 minutes duration. The occurrence of induction and emergence sequelae, and patient acceptance of the technique was assessed by means of a questionnaire. The incidence of unpleasant dreams was 6.7% with midazolam and 26.7% with diazepam. There was no significant difference in any other sequelae. Overall patient acceptance was high at 96.7%. (6) Kumar A, Bajaj A, Sarkar P, Grover VK The effect of music on ketamine induced emergence phenomena. Anaesthesia 1992 May;47(5):438-9 ABSTRACT: The purpose of this investigation was to assess the influence of music on emergence phenomena after ketamine anaesthesia. Fifty ASA 1 patients undergoing minor gynaecological procedures were randomly divided into two equal groups. Patients in the treated group were played music of their choice through headphones from 5 min before induction of anaesthesia to 15 min postoperatively. Although the incidence of emergence phenomena was similar in both groups the effects tended to be more pleasant and acceptable in those to whom music was played. The majority of patients in the study group (80%) expressed their willingness to have a similar anaesthetic in the future compared to 52% in the control group (p less than 0.05) Some individuals have chosen to unfairly label ketamine a "general anesthetic". However, ketamine does NOT meet accepted criteria as a general anesthetic! To follow is a paragraph discussing this issue from a ketamine article from our institution that will be published this spring: "Determination of appropriate monitoring standards for ketamine is problematic, as the unique features of this drug prevent its classification according to existing standards. (1,30,31) As patients receiving ketamine maintain spontaneous breathing and protective airway reflexes without intubation, (1-5) this drug violates the standard definition of general anesthesia, which requires "partial or complete loss of protective reflexes, including the inability to independently maintain an airway." Similarly, ketamine does not meet definitions for either conscious sedation (which requires responsiveness) or deep sedation (which requires depressed airway reflexes and/or inability to maintain an airway). (1,30,31) The state induced by ketamine is fundamentally unique both pharmacologically and clinically, and a fourth distinct category (eg, dissociative sedation) would appear both necessary and appropriate. The low rate of complications noted in this report and others (2,3) support the opinion that standards similar to those specified for conscious sedation are adequate for dissociative sedation. Most importantly, a practitioner must pay careful attention to airway positioning. Additionally, ketamine should be administered either IM or very slowly IV." 1. American College of Emergency Physicians: Pediatric analgesia and sedation. Ann Emerg Med 1994; 23:237-250. 2. Green SM, Nakamura R, Johnson NE: Ketamine sedation for pediatric procedures: Part I - A prospective series. Ann Emerg Med 1990; 19:1024-032. 3. Green SM, Johnson NE: Ketamine sedation for pediatric procedures: Part II - Review and implications. Ann Emerg Med 1990; 19:1033-1046. 4. White PF, Way WL, Trevor AJ: Ketamine - its pharmacology and therapeutic uses. Anesthesiology 1982; 56:119-36. 5. Corssen G, Reves JG, Stanley TH: Intravenous anesthesia and analgesia. Philadelphia, Lea & Febiger, 1988, pages 99-174. 30. National Institutes of Health: Consensus conference - Anesthesia and sedation in the dental office. JAMA 1985; 8:1073-1076. 31. American Academy of Pediatrics: Guidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures. Pediatrics 1992; 89:1110-1115. Expect to see more articles from our group on ketamine in the next 1-2 years. We are currently writing up our 9-year experience using the IM protocol described in reference #2 above. Steve Green, MD Director, Emergency Medicine Residency Program Associate Professor of Emergency Medicine Loma Linda University School of Medicine, Loma Linda, CA E-mail: steven_green@msn.com ------------------------------------------------- Date sent: Sat, 9 Nov 1996 19:54:32 UT Send reply to: Steve Green From: Steve Green Subject: Ketamine induced laryngospasm To: Multiple recipients of list EMED-L Here at Loma Linda we are currently writing up our 9 years' experience with the ketamine 4 mg/kg IM protocol. In >1,000 cases we have had 3 cases of laryngospasm, and all have been brief and without adverse sequelae. We generally avoid intra-oral procedures and regularly use concomitant atropine. Some physicians confuse mild stridor with laryngospasm, and the first step with any noisy breathing should be to reposition the head & airway. (Harvey's case was clearly laryngospasm, of course.) Interestingly, I know two pediatric gastroenterologists who routinely use IV ketamine for endoscopy. Passing the scope produces substantial posterior pharyngeal stimulation, and they encounter transient laryngospasm regularly, sometimes with mild or moderate desaturation. Over several years of use they have never had to intubate a child or encountered any adverse sequelae to such laryngospasm. The 1 in 5,000 risk of laryngospasm requiring intubation quoted by Harvey is from pooled data (1), and the 2 actual cases constituting the numerator are very superficially documented in their original reports (2,3). Laryngospasm is to be respected, but luckily the risk of any serious consquence appears to be extremely low. Ketamine is far more consistently effective than alternative sedating agents, and in my opinion has a broader margin of safety as well. Steve Green MD / Loma Linda University (1) Ann Emerg Med 1990; 19:1033-1046 (2) Anesthesiology 1974; 40:459-464 (3) Anaesthesia 1971; 26:318-323 The Loma Linda University Emergency Department ketamine protocol Purpose To define the guidelines for administration, monitoring, and recovery for pediatric emergency department patients receiving ketamine for procedural sedation. Characteristics of the Ketamine "Dissociative State" 1. Dissociation  Following administration of ketamine the patient passes into a fugue state or trance. The eyes may remain open but the patient does not respond. "The lights are on, but no one's home." 2. Catalepsy  Normal or slightly enhanced muscle tone is maintained. On occasion the patient may move or be moved into a position that is self-maintaining. Occasional muscular clonus may be noted. 3. Analgesia  Analgesia is typically substantial or complete. 4. Amnesia  Total amnesia is typical. 5. Maintenance of Airway Reflexes  Upper airway reflexes remain intact and may be slightly exaggerated. Intubation is unnecessary, but occasional repositioning of the head may be necessary for optimal airway patency. Suctioning of hypersalivation may occasionally be necessary. 6. Cardiovascular Stability  Blood pressure and heart rate are not decreased, and typically are moderately increased. 7. Nystagmus:  Nystagmus is typical. Patient Selection Ketamine is best-suited for children aged 12 months to 10 years. There is an increased risk of airway complications in children younger than 12 months, and ketamine is not recommended in these patients. There is an increased risk of unpleasant emergence reactions in both adults and children older than 10 years, and ketamine is not recommended in these patients. Indications Short, painful procedure, especially those requiring immobilization Complex facial lacerations Reduction and casting of fractures Foreign body removal Abscess incision and drainage Examination judged likely to produce excessive emotional disturbance Pediatric sexual assault examination Contraindications Age less than 3 months (use with extreme caution if 3-12 months of age) History of airway instability, tracheal surgery, or tracheal stenosis Procedures involving stimulation of the posterior pharynx Active pulmonary infection or disease (including upper respiratory infection) Full meal within three hours of procedure Cardiovascular disease including angina, heart failure, or hypertension Head injury associated with loss of consciousness, altered mental status, or emesis Hydrocephalus, central nervous system abnormalities, or masses Glaucoma or acute globe injury Prior adverse reaction to ketamine Psychosis, porphyria, thyroid disorder, or thyroid medication Environment Area with suction, oxygen, and equipment for advanced airway management Physician immediately available who is adept at advanced airway management Intravenous access is not required. Presedation Patients should undergo a pre-sedation assessment in accordance with hospital policy. Educate parents or caretakers regarding the unique characteristics of the dissociative state. Baseline level of consciousness and oxygen saturation will be recorded on the medical record prior to administration of ketamine Ketamine administration Ketamine 4 mg/kg is combined with atropine 0.01 mg/kg (minimum 0.1 mg, maximum 0.5 mg) in the same syringe, and administered IM. The atropine is to minimize oral secretions. Ketamine is not administered until physician is ready to begin procedure (onset of dissociation typically within 5 minutes) Repeat ketamine dose (2-4 mg/kg IM without additional atropine) if sedation is inadequate after 5-10 minutes (unusual) Adjunctive physical restraint if needed to control random motion (occasional) Adjunctive local anesthetic if needed for incomplete analgesia (unusual) Interactive Monitoring Mandatory close observation of airway and respirations by an experienced health care professional until recovery well-established THE PATIENT IS NEVER LEFT ALONE. Drapes positioned such that airway and chest motion can be visualized at all times Occasional repositioning of the head may be indicated for optimal airway patency. Occasional suctioning of the anterior pharynx may be necessary. Mechanical Monitoring Continuous pulse oximetry until recovery is well-established Continuous cardiac monitoring until recovery is well-established Potential side effects Airway malalignment requiring repositioning of head (0.7%) Transient laryngospasm (0.4%) Transient apnea or respiratory depression (0.3%) Hypersalivation (1.7%) Emesis while sedated (0.8%) Emesis well into recovery (5.9%) Unpleasant recovery agitation or dreams (mild in 7.8%, moderate or severe in 0.9%) Muscular hypertonicity and random, purposeless movements are common. Clonus, hiccuping, and/or rash may occur. Recovery area Minimal physical contact or other psychic disturbance Quiet area with dim lighting if possible Advise parents or caretakers not to stimulate patient prematurely Median time from injection to discharge is 106 minutes (typical range 60-140 minutes). Discharge criteria Return to pre-treatment level of verbalization and awareness Return to pre-treatment level of human recognition Return to pre-treatment level of purposeful neuromuscular activity Discharge instructions Nothing by mouth for 2 hours Careful family observation and no independent ambulation for 2 hours -------------------------------- Date sent: Sat, 9 Nov 1996 18:12:24 -0600 Send reply to: Harvey Louzon From: Harvey Louzon Subject: Forward from PED-EM-L: muscle relaxants in children To: Multiple recipients of list EMED-L On Fri, 8 Nov 1996, Anthony L. Palomba wrote: > Barbara W. Brandom, M.D., Prof. Anesthesiology/Critical Care > Medicine at Univ. of Pittsburgh School of Medicine recently > published a wonderfully concise review: "Muscle relaxants in > infants and children, how they differ from adults"; ASA > REFRESHER COURSES IN ANESTHESIOLOGY: vol.24;chapt.2;1996;pp. > 13-19. In it we are reminded of a number of reported cases of > sudden, unsuspected hyperkalemic cardiac arrest in children > given succinylcholine in patients with subclinical myopathies. > There are also recorded cases of jaw rigidity with > significant > myoglobinuria and CPK elevations not thought to be due to > malignant hyperthermia. I have personally been involved with a > case of the latter. > > To my knowledge a defasiculating dose of non-depolarizing > muscle relaxant will not protect against these effects. This > is why many have discontinued routine use of succinylcholine. I actually replied to this post but the cows on PED-EM have been ruminating excessively about it and it hasn't been posted yet. Since this issue has, again, been raised I've reproduced part of my response below: It is precisely for reasons of this sort that *elective* use of succinylcholine has been discontinued in children. The revised FDA labeling of sux does, indeed, sanction its use in emergency situations such as the present case. Even the authors of the reports of hyperkalemia after the use of sux in children acknowedge its legitimate use in emergency situations (1). The cases of hyperkalemia described in children after the use of sux have generally occured after repeated doses of the drug or unrecognonized pre-existing hyperkalemia, acidosis or myopathy. These have all been described in an elective setting and, to my knowledge, have not occured in crash intubations. In a series of over 5000 children only 3 developed the syndrome of masseter muscle spasm (2). H. Louzon MD (1) Schulte-Sasse U [Heart arrest in children after intravenous injection of succinylcholine in the ENT operating room (see comments)] HNO 1995 Nov;43(11):676-9 Acute rhabdomyolysis with hyperkalemia has been followed by ventricular dysrhythmia, cardiac arrest and death after the administration of succinylcholine to apparently healthy children who were subsequently found to have undiagnosed skeletal muscle myopathies. Boys have mostly been affected. Reports of anesthesia emergencies from the United States and Germany have indicated that serious side effects of succinylcholine are not as rare as previously thought. This disorder often presents as sudden cardiac arrest within minutes after the administration of the drug. The tragedy is that an apparently healthy child dies abruptly during what was considered to be a relatively uncomplicated surgical procedure (most often in ENT surgery). Due to the abrupt onset of rhabdomyolysis, routine resuscitative measures are likely to be unsuccessful. Extraordinary measures (including institution of extracorporeal circulation) and prolonged efforts have resulted in successful resuscitation of some cases. Since there are usually no signs or symptoms to alert the practitioner to patients at risk, the use of succinylcholine in children should be reserved for emergency intubations or instances in which immediate securing of the airway is necessary. (2) Lazzell VA, Carr AS, Lerman J, Burrows FA, Creighton RE The incidence of masseter muscle rigidity after succinylcholine in infants and children [see comments] Can J Anaesth 1994 Jun;41(6):475-9 To determine whether the incidence of masseter muscle rigidity is affected by the anaesthetic induction sequence, we prospectively studied for ten months the anaesthetic course in 5,641 infants and children who received muscle relaxation to facilitate tracheal intubation. The anaesthetic induction sequence consisted of intravenous sodium thiopentone (STP) 5 mg.kg-1 alone, halothane induction alone 1-4%, or halothane followed by STP. Inhalational inductions with halothane included nitrous oxide and oxygen. Tracheal intubation was facilitated by either intravenous succinylcholine (Sch) at least 1.5 mg.kg-1 or by a non-depolarizing muscle relaxant. The induction sequence and all episodes of MMR were recorded. Ninety percent of the patients received Sch and 10% received a non-depolarising agent. Of those who received Sch, 88% (5,064 patients) were anaesthetised with STP and 12% (607 patients) were anaesthetised with halothane alone or halothane followed by STP. Masseter muscle rigidity was defined clinically by the transient inability to distract the mandible from the maxilla such that the mouth could not be opened or could only be opened with force. No children anaesthetised with STP followed by Sch developed MMR. One child (0.9%) developed MMR after halothane and Sch and two developed MMR after halothane, STP and Sch (0.4%). The incidence of MMR after Sch was less with STP than with halothane alone or with halothane and STP (P < 0.025). The peak CPK values in the three children who developed MMR were 17,580 IU.L-1 after halothane and Sch, and 7,280 IU.-1 and 3,273 IU.-1 after halothane, STP and Sch. There was no evidence of MH reactions in these patients.(ABSTRACT TRUNCATED AT 250 WORDS) ------------------------------- Date sent: Fri, 9 May 1997 03:13:00 BST-1 Send reply to: "EMED-L is a list for hospital based emergency medicine practitioners." , Rowland Cottingham From: Rowland Cottingham Subject: Ketamine (was prehospital CVA) To: Multiple recipients of list EMED-L I ask because I did a literature review for my paper on "Use of ketamine for prolonged entrapment" (J Accident and Emergency Med 1994;11:189-91) and turned up 2 Japanese case reports of patients undergoing neurosurgery who already had space occupying lesions. The intracranial pressure rose transiently on administration of ketamine and the rise was immediately abolished by IPPV. I regard these papers as completely irrelevant to the prehospital situation. The greatest benefit of ketamine is in the pain relief and calming. I use small subanaesthetic doses titrated as necessary; using 25mg iv boluses I usually give women 50 and men 75mg. If you need full anaesthesia doubling this is usually quite adequate. I contend that any small rise in ICP from this is more than compensated for by the reduction in venous pressure (and hence rise in CPP) that abolishing all that struggling produces. --------------------------------- "Is anyone aware of a series of laryngospasm with Ketamine? One of our plastic surgeons, who uses morphine and Versed for kids, feels that the risk of this complication is unacceptable." This opinion is without factual basis. In the past decade at Loma Linda University we have administered ketamine to 1200+ children in our ED, and have observed 4 transient episodes of laryngospasm with no adverse outcome (0.3% incidence). (1) This is less than the 2.3% incidence of laryngospasm reported for pediatric inhalational anesthesia, (2,3) and similar to the up to 1% incidence of laryngospasm described with IV midazolam. (4) In the 27 years that ketamine has been on the market (and given to probably millions of patients) there are only 2 reports in the literature of ketamine-associated laryngospasm leading to intubation in patients lacking standard contraindications, (5) and in both of these cases no adverse outcome was described. No only is the ketamine "dissociative state" far more effective for performing ED procedures than Versed, I believe that its safety profile is similar if not superior. Once you start using it, you will wonder how you ever did these procedures without it. I would like to hear from anyone who has ever seen a real complication with ketamine in patients lacking standard contraindications. Such an occurrence would constitute a reportable case. Steve Green, MD / Loma Linda University ********************* (1) Green SM, Rothrock SG, Lynch EL, Ho M, Harris T, Hestdalen R, Garrett W, Hopkins A: Intramuscular Ketamine for Pediatric Procedural Sedation in the Emergency Department: Safety and Efficacy With 1,022 Cases. [abstract] Academic Emergency Medicine 1997; 4:364. (2) Borland LM, Saitz EW, Woelfel SK: Evaluation of pediatric anesthesia care. [abstract] Anesthesiology 1989; 71:A920. (3) Holzman RS: Morbidity and mortality in pediatric anesthesia. Pediatr Clin North Am 1994; 41:239-256. (4) Roche Laboratories: Midazolam package insert. Nutley, New Jersey, June 1994. (5) Green SM, Johnson NE: Ketamine sedation for pediatric procedures: Part 2, Review and implications. Ann Emerg Med 1990; 19:1033-1046. --------------------- (1) Hersack R A.. Ketamine's psychological effects do not contraindicate its use based on a patient's occupation. Aviat Space Environ Med 1994; 65:1041-1046. ABSTRACT: Since ketamine was approved for clinical use, there has been debate over whether the psychological effects of ketamine warrant avoiding use of the drug in patients based on their occupation. This article reviews the literature to determine if such concerns are valid. After 25 years of clinical experience with ketamine, fewer than 10 cases document the occurrence of delayed psychological effects potentially attributable to that drug. In most cases, the delayed effects were temporary, resolving within 3 weeks. Further, there were no long-term psychological effects clearly attributable to ketamine. Children who manifested delayed effects had several other factors present placing them at risk for long-term psychological changes independent of their receiving ketamine. Several controlled studies investigating the risk of long-term psychological effects due to ketamine fail to document that the risk of permanent psychological changes from ketamine is any greater than that from any other anesthetic. In conclusion, there is no evidence in the literature that ketamine presents a higher risk compared to other anesthetics for causing long-term psychological effects that result in a patient not being able to return to his or her occupation. The decision of whether to use ketamine should be a clinical decision weighing relative risks versus benefits, and not a decision based on the patient's career. 56 ref. Author.