Neuraxial anesthesia (NA) refers to the use of local anesthetics around the spinal cord to effectuate analgesia in large areas of the body through the deactivation of ascending pain pathways.1 Neuraxial anesthesia includes epidural anesthesia, spinal anesthesia, and combined spinal-epidural (CSE) anesthesia.1 As with any procedure, there are specific populations for which NA is best indicated as well as populations for which there is greater concern for the onset of adverse side effects. In particular, age is an important consideration when neuraxial anesthesia is being used.
Hypotension, an adverse side effect of NA caused by its sympatholytic effects, has multiple risk factors.2 Older age – specifically, age ≥40 years – was found to have a statistically significant association with hypotension after spinal anesthesia (odds ratio [OR] 2.4; p <0.001).2 Another study, using regression models, also yielded data supporting this conclusion (p <0.0001).3 Meanwhile, age <50 years was associated with increased risk of developing bradycardia during spinal anesthesia (p <0.05).3
Research has also found that age is a factor in the risk of urinary retention after neuraxial anesthesia, an extremely uncomfortable symptom that may require invasive intervention. A 2010 study found statistically significant age-sex dual variables associated with spinal anesthesia-related risk of urinary retention.4 Women aged <40 years were found to have 6-fold greater risk (OR 6.125) of developing urinary retention compared to women aged 40–60 years. Meanwhile, men aged >60 years were 5-fold more likely to develop urinary retention (OR 5.25) when compared with younger men.4 Additionally, this study found that age >60 years, irrespective of patient sex, had higher incidence of urinary retention,4 thought to be related to the age-related degeneration of central, supraspinal somatic, and visceral neurons.5
Spinal epidural hematomas (SEH) are rare but serious complications with high morbidity. They occur when blood accumulates in the epidural space, compressing the spinal cord.6 A 2023 meta-analysis of 29 cohort studies found that age ≥60 years was associated with greater risk (OR 1.35; 95% CI: 1.03-1.77) of developing SEH.7 Meanwhile, on the other end of the spectrum, younger age was found to have higher risk of epidural anesthesia failure (OR 0.91; 95% CI: 0.86-0.95).9
However, increased age does not preclude the use of neuraxial anesthesia. In a 2022 study assessing the safety and feasibility of spinal anesthesia when used in simple and complex lumbar spine surgery, patients age ≥80 years were found to have similar rates of spinal headache (p >0.99), deep vein thrombosis (p >0.99), pneumonia (p >0.99), urinary retention (p >0.99), and 30-day readmission (p >0.99) when compared to those aged <80 years. 8
In conclusion, NA represents a collection of catheter-based techniques, often used as alternatives to general anesthesia, for pain management in the operative patient. Older age predisposes patients to many complications with neuraxial anesthesia, such as hypotension, urinary retention, and formation of SHE. Elderly patients may benefit from NA techniques during specific surgeries; however, its benefits should be weighed against the increased risk of several complications with increased patient age. Meanwhile, younger age, while associated with fewer complications, may be associated with a higher risk of bradycardia and epidural analgesia failure.
References
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3. Tarkkila P, Isola J. A regression model for identifying patients at high risk of hypotension, bradycardia and nausea during spinal anesthesia. Acta Anaesthesiol Scand. 1992;36(6):554-558. doi:10.1111/j.1399-6576.1992.tb03517.x
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7. Luo M, Cao Q, Zhao Z, et al. Risk factors of epidural hematoma in patients undergoing spinal surgery: a meta-analysis of 29 cohort studies. Int J Surg Lond Engl. 2023;109(10):3147-3158. doi:10.1097/JS9.0000000000000538
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