Is ketamine used as a bronchodilator?

From the Guidelines

Ketamine is not recommended as a primary bronchodilator for respiratory conditions. While ketamine does have some bronchodilatory properties through its sympathomimetic effects and NMDA receptor antagonism, it is not approved or typically used for this purpose in standard clinical practice 1. In emergency situations involving severe bronchospasm or status asthmaticus unresponsive to conventional treatments, ketamine may be considered at doses of 0.1-0.5 mg/kg IV as an adjunctive therapy. However, this use should be reserved for critical care settings under close monitoring due to potential side effects including increased secretions, hallucinations, and hemodynamic changes.

First-line bronchodilator treatments for asthma or COPD exacerbations should include beta-2 agonists (like albuterol), anticholinergics (like ipratropium), and corticosteroids, as these have been shown to increase FEV1, reduce dynamic hyperinflation, and improve exercise performance 1. The bronchodilatory effect of ketamine occurs because it stimulates catecholamine release and inhibits reuptake, leading to increased circulating epinephrine and norepinephrine which relax bronchial smooth muscle. Despite these properties, ketamine's risk profile and the availability of more effective and specific bronchodilators limit its routine use for this indication.

Some key points to consider when treating respiratory conditions include:

• Using inhaled agents in small doses, which are as efficacious as oral preparations and have fewer side effects 1
• Considering combined nebulised treatment with a β agonist and ipratropium bromide in more severe cases 1
• Monitoring patients closely, especially in critical care settings, due to potential side effects of treatments. Overall, the use of ketamine as a bronchodilator should be approached with caution and considered only in specific emergency situations where conventional treatments have failed.

From the FDA Drug Label

Ketamine is a potent bronchodilator suitable for anesthetizing patients at high risk for bronchospasm.

Ketamine can be used as a bronchodilator. It is suitable for anesthetizing patients at high risk for bronchospasm, as stated in the drug label 2 and 2.

• Key points:
  • Ketamine is a potent bronchodilator
  • Suitable for patients at high risk for bronchospasm
  • Can be used for anesthetizing patients with this condition

From the Research

Ketamine as a Bronchodilator

• Ketamine has been studied as a potential bronchodilator in acute severe asthma, with some studies showing improved outcomes and alleviation of the need for mechanical ventilation 3, 4.
• The use of ketamine in severe acute bronchospasm has been investigated, with mixed results: one study found no association between ketamine use and improvement in respiratory mechanics 5, while others have reported positive effects 3, 4, 6, 7.
• In pediatric patients with acute asthma exacerbation, ketamine has been shown to lead to improvements in respiratory parameters, including decreased clinical asthma scores and increased peak expiratory flow 6.
• The safety and efficacy of ketamine as a bronchodilator have been evaluated, with reports of manageable side effects, such as increased tracheobronchial secretions and hallucinations, and no significant changes in heart rate and blood pressure 6, 7.

Clinical Implications

• Ketamine may be considered as an adjunct therapy in acute severe asthma, particularly in cases that are refractory to conventional treatment 3, 4.
• The use of ketamine should be carefully considered and monitored for adverse events, especially in pediatric patients 6.
• Further research is needed to fully evaluate the effectiveness and long-term effects of ketamine as a bronchodilator in acute severe asthma 3, 4, 6.

Studies and Findings

• A review of 20 reports on the use of ketamine as a bronchodilator in acute severe asthma found improved outcomes and alleviation of the need for mechanical ventilation 3.
• A randomized controlled trial found no association between ketamine use and improvement in respiratory mechanics in adult patients with severe acute bronchospasm 5.
• A prospective observational study found that ketamine significantly decreased peak airway pressure and PaCO2 and increased PaO2 in patients with status asthmaticus 7.