From the Guidelines
Ketamine should be used with extreme caution in elderly patients with myocardial infarction (MI) due to its potential to increase heart rate, blood pressure, and cardiac output, which could exacerbate myocardial ischemia. The use of ketamine in this population is concerning because it can lead to a dose-dependent increase in heart rate, blood pressure, and cardiac output, mediated through stimulation of the sympathetic nervous system 1. This effect is particularly worrisome in patients with ischemic heart disease, as it may increase myocardial oxygen demand and potentially worsen ischemia.
While ketamine can provide effective analgesia and sedation, its potential cardiovascular effects make it a less desirable choice for elderly MI patients. If ketamine is deemed necessary, it should be administered at reduced doses (starting at 0.1-0.3 mg/kg IV for analgesia) and with careful hemodynamic monitoring 1. The medication should be given slowly to minimize cardiovascular effects, and clinicians should be prepared to manage potential hypertension or tachycardia.
Some key points to consider when using ketamine in elderly MI patients include:
- Careful dose titration to minimize cardiovascular effects
- Close monitoring of hemodynamic parameters
- Preparation to manage potential hypertension or tachycardia
- Consideration of alternative analgesics or sedatives that may be safer in this population, such as fentanyl, morphine, or etomidate. It is essential to weigh the potential benefits of ketamine against its risks in elderly MI patients and to consider alternative options that may be safer and more effective in this population 1.
From the Research
Detrimental Effects of Ketamine on Elderly MI Patients
- There is limited research directly addressing the detrimental effects of ketamine on elderly patients with myocardial infarction (MI) [ 2 ].
- A study published in 2021 found that ketamine can cause mild to moderate transient increases in blood pressure, heart rate, and cardiac output in adults, which may exacerbate underlying cardiac disease [ 2 ].
- The same study found that 9.7% of patients older than 50 years receiving ketamine for procedural sedation had new onset ischemia on electrocardiogram (ECG), but there were no statistically significant differences between the groups [ 2 ].
- Another study published in 2022 found that long-term use of β-blockers in elderly patients with coronary artery disease (CAD) without MI was associated with an increased risk of adverse cardiovascular events, including admission for heart failure [ 3 ].
- However, this study did not specifically investigate the effects of ketamine on elderly MI patients [ 3 ].
- Other studies have investigated the use of cardiovascular medications in elderly patients with MI, but not specifically the effects of ketamine [ 4 , 5 , 6 ].
Considerations for Ketamine Use in Elderly MI Patients
- Careful attention should be made in patient selection when ketamine is the desired agent for procedural sedation [ 2 ].
- Consideration might be made in using the lowest possible dose of ketamine to obtain adequate sedation in order to lessen the occurrence of ECG changes suggestive of myocardial ischemia [ 2 ].
- The use of ketamine in elderly MI patients should be approached with caution, taking into account the potential risks and benefits [ 2 ].