How Sedation Affects Cognitive Function in Older Adults

Sedation offers a state of calmness, relaxation, or sleepiness due to certain sedative drugs. These medications are usually given intravenously but can sometimes be provided orally or with a face mask. Sedatives have numerous applications, including alleviating anxiety and relaxing muscles before surgeries and procedures, such as:

• Dental surgery
• Lumbar puncture 
• Minor foot or skin surgery
• Bone or joint realignment
• Breast biopsy
• Endoscopy
• Bronchoscopy 

Although helping patients feel more relaxed during the procedures, sedatives affect a patient’s level of awareness and consciousness. There is a concern about elderly patients undergoing sedation and how they might be affected by its possible long-term complications and side effects. Approximately 30% of all surgeries are performed on people over the age of 70. Safe sedation training can help healthcare providers learn the best sedation practices and techniques to protect the cognitive capacity of patients of all ages, especially elderly individuals. The ability to determine an accurate dosage for a patient is extremely important. 

Sedation and Its Effects on Cognitive Function in Older Adults

A pillar of modern medicine is ensuring patients are as comfortable as possible during surgery or procedures for diagnosing medical conditions. Hence, sedation has become a standard of care for physicians and other healthcare professionals to help patients control pain and increase their comfort during medical procedures. These may be performed in a hospital or an outpatient setting, like a same-day surgery center, a doctor’s office, or a dentist’s office. Since elderly patients tend to be more sensitive to pain, they may be in need of more comfort. They also may have concomitant diseases associated with aging so they can often require sedation in a hospital setting. There is a concern about how sedation impacts the cognitive function of older adults (since they have less cognitive reserve), and the medical society is still monitoring and studying this aspect.

Sedation relies on benzodiazepines, barbiturates, hypnotics, narcotics, and miscellaneous sedatives such as ramelteon and suvorexant. Higher than needed doses of these medications can cause complications (decreased levels of consciousness and respiratory depression), which may require intubation and mechanical ventilation. In patients 65 years and older, physicians and other healthcare professionals can avoid (or minimize) giving benzodiazepines, phenothiazines, centrally acting cholinergic, meperidine, and antipsychotics during the perioperative period, decreasing the risk of cognitive changes.

Side effects of sedation affect every age group. The short-term side effects of sedatives include slowed reaction times and reflexes, numbness, sleepiness, dizziness, difficulty focusing or thinking, and blurred vision. There are also some risks and complications of sedation, such as frequent forgetfulness or memory loss, withdrawal symptoms, and depression symptoms, such as tiredness and hopelessness. In older patients, sedation can cause delirium, dementia, or mild cognitive impairment.

For instance, older patients tend to have Postoperative Cognitive Dysfunction (POCD) after receiving a certain level of sedation. POCD is a short-term loss of cognitive function that mainly affects memory and executive functions used for daily activities, including working memory, flexible thinking, and self-control. POCD typically lasts from a few days to a few weeks. Patients aged 60 years or older are at significant risk for long-term cognitive function issues.

Factors That Influence the Impact of Sedation on Cognitive Function in Older Adults

Sedation involves the use of prescription medications that slow your brain’s activity. Common ways sedation affects the body include:

• Decreased anxiety
• Decreased muscle function
• Reduced sensitivity to pain and touch
• Drowsiness
• Memory loss
• Relaxed feeling
• Shallow breathing
• Slowed heart rate
• Interruptions in your memory

These effects can also disrupt or affect cognitive functions. Recent research suggests that disrupting central nervous system (CNS) function may result in unwanted mental effects in some individuals. Scientists believe the body's inflammatory response to surgery or other medical procedures is an essential factor that influences the impact of sedation on cognitive functions. The study indicates that another significant risk factor in elderly patients may be a relative 'anesthetic overdose.' Other risk factors include:

• Age
• Level of education
• Mental health
• Compromised higher-level cognitive skills
• Systemic inflammatory markers
• Procedure characteristics such as invasiveness, duration, and urgency
• Postoperative admission to an intensive care unit 

Doctors and other healthcare professionals should start a detailed patient evaluation when there are significant risk factors. It should include a thorough conversation with the patient, their family or caregivers, and the entire perioperative team. To address and optimize modifiable risk factors before the patient undergoes elective surgery and other procedures, clinicians should perform a full health assessment, including the following: 

• Functional status and baseline frailty score
• Depression
• Hypertension
• Sleep disorders
• Glycemic and diabetes control
• Alcohol and other substance use/dependence
• Cessation of nonessential medications 
• Review of essential medicines
• Monitoring for potential interactions
• Nutritional status
• Family and social support system

Recommendations for Minimizing the Impact of Sedation on Cognitive Function in Older Adults

In preparation for surge­ry, it is recommended to maintain a healthy lifestyle. This practice can be beneficial in preventing cognitive dysfunction in older adults. The importance of maintaining a healthy lifestyle cannot be overstated. It involves various factors, such as consuming a balance­d diet and engaging in regular e­xercise. Also, other beneficial strategies that can be incorporated into elderly patients’ routines should include stress relief and fostering healthy sle­ep patterns.

During recove­ry, providing mental stimulation and physical rehabilitation can effe­ctively prevent cognitive­ decline. To facilitate recove­ry, elderly patients need to stay active. Preventative measures and care­ful planning alongside the healthcare team can effectively mitigate the likelihood of cognitive­ complications.

Clinicians and healthcare providers should maintain a prudent approach to prescribing sedative drugs and using sedation. Discussions with surgeons and ane­sthesiologists regarding medication choices and monitoring can significantly reduce potential risks. They should also ensure there is comprehensive ge­riatric evaluation. ­

Conclusion

Sedation is often used to enhance comfort and re­laxation during medical procedures. However, it can pote­ntially impact cognitive function, especially in older adults. High doses of sedative me­dications may lead to complications, such as decrease­d consciousness and respiratory depre­ssion. Elderly individuals undergoing se­dation face the risk of expe­riencing postoperative cognitive­ dysfunction (POCD), which can affect their memory and daily life. It is worth considering various influe­ncing factors like age, inflammation, and health status when evaluating the effect of sedation on cognitive function. Healthcare professionals should conduct thorough assessments and optimize modifiable­ risk factors before performing procedures. Also, the judicious use of sedation, an active recovery program, and maintaining a healthy lifestyle can help reduce its effects on the cognitive function of older adults.