Can ketamine cause dyspnea (difficulty breathing)?

From the Guidelines

Ketamine can cause shortness of breath, although it is not a common side effect, and its use requires careful monitoring, especially in patients with underlying respiratory conditions. When used medically, typically at doses of 0.5-2 mg/kg IV for anesthesia or 0.1-0.5 mg/kg IV for pain management, ketamine can occasionally lead to respiratory depression, particularly when combined with other sedatives or in patients with pre-existing respiratory issues 1. This occurs because ketamine affects multiple neurotransmitter systems, including NMDA receptors and opioid receptors, which can influence respiratory drive.

Key Considerations

• Ketamine generally preserves respiratory function better than many other anesthetics but can cause increased secretions in the airways, contributing to breathing difficulties.
• Patients with asthma or chronic obstructive pulmonary disease should be monitored carefully due to the potential for bronchospasm or respiratory complications.
• The combination of ketamine with other sedatives, such as benzodiazepines or opioids, may increase the risk of respiratory depression, as seen in studies where the combined use of these agents resulted in higher rates of hypoxemia and apnea 1.

Safety and Efficacy

• Studies have shown that ketamine can be safely administered for procedural sedation and analgesia in both pediatric and adult populations, with a low rate of significant adverse events 1.
• A well-designed randomized controlled trial found that a ketamine and midazolam combination was safer and more efficacious than a fentanyl and midazolam combination for sedation in orthopedic procedures, with lower rates of hypoxia 1.
• However, it is crucial to follow recommended dosages and to titrate drugs carefully to minimize the risk of complications, including respiratory depression.

Monitoring and Care

• If shortness of breath occurs after ketamine administration, it is essential to inform healthcare providers immediately, as this could indicate an adverse reaction requiring prompt medical attention.
• Continuous monitoring of respiratory function and oxygen saturation is recommended during and after ketamine administration, especially in high-risk patients.

From the FDA Drug Label

Respiratory disorders: Respiratory depression and apnea following rapid intravenous administration of high doses of ketamine hydrochloride; laryngospasm, and airway obstruction. Yes, ketamine can cause shortness of breath, as it may lead to respiratory depression and apnea. Key points to consider:

• Respiratory depression can occur, especially with high doses or rapid administration.
• Apnea (temporary cessation of breathing) is also a possible adverse reaction.
• Laryngospasm and airway obstruction can further contribute to breathing difficulties. 2 2

From the Research

Ketamine and Shortness of Breath

• There is evidence to suggest that ketamine can cause shortness of breath in certain individuals, particularly those with a history of ketamine use disorder 3.
• A study published in the European journal of case reports in internal medicine found that a 28-year-old female with a history of recurrent cystitis and ketamine use disorder presented with bilateral lower extremity oedema and shortness of breath for 3 months 3.
• However, other studies have found that ketamine can actually activate breathing and abolish the coupling between loss of consciousness and upper airway dilator muscle dysfunction 4.
• A randomized, controlled, cross-over, pharmaco-physiologic study in 12 rats found that ketamine anesthesia was associated with markedly increased genioglossus activity and a respiratory stimulating effect 4.
• It is worth noting that the majority of side effects associated with ketamine are mild, transient, dose dependent, and attenuate with subsequent treatments 5.
• Additionally, ketamine has been found to have rapid-acting antidepressant effects, which may be useful in treating therapy-resistant depressive patients, but its use can also be associated with severe cardiovascular complications, including acute systolic heart failure 6, 3.