Ketamine: Its Effect on Airway Resistance in Man

The Efficacy of Ketamine in Pediatric Emergency Department Patients Who Present With Acute Severe Asthma

“…14 Previously described case series have reported the successful use of ketamine in the management of patients with asthma exacerbations that were recalcitrant to traditional therapies; however, the dosing regimens and severity of patient illness varied significantly because some patients were intubated. 11,12,[15][16][17][18][19] In contrast, our randomized trial found that ketamine added no additional benefit to standard therapy for nonintubated children with a moderately severe asthma exacerbation, even though our dosing regimen was greater than several of those that reported success. 11,12,15 Although it was a negative study outcome, the previously published randomized trial of ketamine for asthma by Howton et al 20 was difficult to generalize to children, given its exclusion of patients younger than 18 years and dysphoria that resulted in the lowering of the bolus dose.…”

“…of circulating catecholamines to increase bronchodilation, 11 blocking calcium influx, 12 and directly relaxing smooth muscle by reducing vagally mediated bronchoconstriction. 13 …”

“…Huber et al reported measurable bronchodilation in intubated patients using a loading dose of 0.1 mg/lb. 11 Sarma later reported avoiding intubation in 2 adults using a ketamine infusion of 0.15 mg/kg per hour, 12 whereas Nehama et al 15 reported successful bronchodilation of an intubated infant at a rate of 0.2 mg/kg per hour. The range of published successful dosing strategies of ketamine infusions, as well as the patient cohorts who received it, has varied significantly.…”

Intravenous Ketamine in a Dissociating Dose as a Temporizing Measure to Avoid Mechanical Ventilation in Adult Patient with Severe Asthma Exacerbation

“…Ketamine has demonstrated bronchodilatatory properties in both in vitro studies (relaxing bronchial smooth muscles) and mechanically ventilated status asthmaticus patients (decreasing mean airway pressure and PaCO 2 and increasing PaO 2 ) (14 -19). Suggested mechanisms of bronchodilatation include: sympathomimetic effect, direct relaxant effect, antagonism to histamine and acetylcholine, calcium influx blockage, and a membranestabilizing effect, as with local analgesics (17,18,20,21). It is also possible that the dissociating effect of ketamine may result in anxiolysis and a decrease in the work of breathing without depressing the respiratory drive.…”

Drug Therapy Approaches in the Treatment of Acute Severe Asthma in Hospitalised Children

“…[189,190] Ketamine increases catecholamine levels by blocking the reuptake of noradrenaline. [191] As an anaesthetic it produces sedation, analgesia and anaesthesia.…”