Ketamine events

Anticonvulsant drugs such as carbamazepine, diazepam, valproic acid, and phenobarbital also slightly increased the duration of the initial AD. However, the effects of these drugs on the other associated seizure events were quite different from PCP and ketamine. The effects of carbamazepine and diazepam, typical of the four compounds, are illustrated in figure 4. These compounds either suppressed the rebound spiking (diazepam, valproic acid, and phenobarbital) or lengthened the total seizure duration with no rebound suppression (carbamazepine). 

In a study of 21 outpatients with refractory neuropathic pain treated with oral ketamine, 17 reported adverse events (20). The most common were light-headedness, dizziness, tiredness, headache, a nervous floating feeling, and bad dreams. The adverse effects were sufficiently important to prevent ten patients from continuing with the trial. 

In a prospective observational study of the prevalence of adverse behavioral events, such as anxiety and sleep disturbance, in the 2-week period after discharge from the emergency department, in children aged 3 months to 18 years, the prevalence of behavioral disturbances was low in those who received fentanyl 4-midazolam ( = 109) however, when compared with those who received ketamine-b midazolam ( = 120), the fentanyl-b midazolam group had a 2.6 times increased odds of being in the highest quintile of the Post Hospital Behavior Questioimaire [42 ]. 

The effects of a combination of morphine and a subanesthetic dose of ketamine have been studied in 41 patients undergoing thoracotomy in a double-blind, randomized study [131. The addition of ketamine reduced morphine consumption by 45%, achieved equivalent pain management, and was associated with fewer adverse events. 

Respiratory In a meta-analysis of the occurrence of all airway and respiratory adverse events, and the specific occurrence of laryn-gospasm and apnea in 8282 children who received ketamine sedation in an Emergency Department, the incidence of airway and respiratory problems was 319/8282 (3.9%), of which 22 (0.3%) were laryngo-spasm and 63 (0.8%) were apnea [25 ]. Children aged under 2 years and 13 years and over had the highest rates of overall adverse events (OR = 2.72 95% Cl = 1.97, 3.74). Adverse airway and respiratory events were less common with low doses... 

In a randomized blind comparison, patients undergoing sedation for emergency procedures received either ketamine 0.3 mg/kg or fentanyl 1.5 micrograms/kg followed by intravenous propofol 0.4 mg/ kg bolus [62 ]. All five severe events were in those who received fentanyl and fentanyl caused more mild (OR = 5.9), moderate (OR = 3.8), and severe (OR = 12.3) adverse events. Desaturation was the main contributor to this difference. Fentanyl was 5.1 times more likely to cause sedation than ketamine, and this persisted after adjustment for age, weight, procedure type, and pre-procedure pain (OR = 4.6). 

Cardiovascular In patients undergoing orthopedic reduction or abscess drainage who were randomized to ketamine 0.3 mg/ kg (n = 32) or fentanyl 1.5 micrograms/kg (n = 31) intravenously, the latter had significantly more cardiorespiratory events (5.1 times the odds for serious events) only 16% did not experience any cardiorespiratory events, compared with 53% of those who received ketamine [63 ]. Of those who received fentanyl, 32% reported mild cardiorespiratory events, 36% moderate, and 16% severe. In those who received ketamine, the incidences were 25%, 22%, and 0% respectively. 

Drug administration ronte Ketamine can be associated with long recovery periods and potential psychiatric adverse events. All patients who had received ketamine for out-patient emergency procedural sedation at a tertiary children s hospital were entered into a sedation registry and retrospectively identified [63 ]. Of 229 patients 48% received ketamine intramuscularly and 52% intravenously. The mean doses were higher in the former (3.7 versus 1.5 mg). Adverse events occurred in 35% of... 

Strayer RJ, Nelson LS. Adverse events associated with ketamine for procedural sedation in adults. Am J Emerg Med 2008 26(9) 985-1028. 

A randomised double-blind placebo-controlled trial [33 ] investigating ketamine in the management of cancer pain demonstrated no improvement with escalating doses of ketamine (100, 300 and 500 mg) delivered subcutaneously over 24 h. There was, however, a statistically significant increase in adverse events in the ketamine group. This included cognitive disturbances, dizziness, site irritation, somnolence and nausea. 

A further study reviewed 18 patients over a 3 year period with acute agitation and psychiatric illness requiring aero medical retrieval imder the mental health act [5(T]. Intravenous ketamine for sedation of patients was used as an alternative to a general anaesthetic and intubation. Patients were given up to two bolus doses of 0.5-1 mg/kg followed by an infusion of 1-1.5 mg/kg/hr. Only mild adverse events occurred with four patients having hypertension and tachycardia all of which spontaneously resolved. One patient vomited but there were no incidences of aspiration and no airway intervention was required. Thus ketamine could be considered as a safe alternative to general anaesthetic in this study population. 

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