Risks of Surgery and Anesthesia in Elderly Patients
It is estimated that in the United States, 15 million surgeries per year are performed on patients who are aged 65 and older. Surgery in this group, however, requires special considerations. In addition to organs having a steady decline of functional reserve, the presence of chronic diseases such as hypertension, diabetes, and coronary and cerebrovascular disease are more likely to be present. It is important for patients to understand the preoperative process and ask questions in order to remain informed, understand their risks, and make appropriate decisions that meet their needs and align with their wishes.
When appropriate, surgery may be scheduled in an ambulatory surgery center, often referred to as “day surgery.” This may be done for certain surgical procedures, including cataracts, colonoscopies, carpal tunnel repairs, knee arthroscopies and hernia repairs. However, these procedures may need to be done in a hospital if the patient has a complicated medical history or needs assistance after surgery. Functional status assessments of the patient's ability to perform Activities of Daily Living (ADL) without assistance must be made. The 5 activities in ADL include eating, dressing, using the toilet, transferring and walking, and bathing. The patient should discuss with their family, surgeon, and primary care physician if they are suitable for ambulatory surgery and whether they will need home health care.
The surgeon may request preoperative testing. There are no mandatory preoperative tests or studies based solely on age. Rather, the decision to order tests depends on the presence of disease and type of surgical procedure. Studies may be ordered to establish a baseline, screen for common disease or assess the severity of a known disease in order to optimize a patient before their procedure. Some common tests include an electrocardiogram (EKG), basic metabolic panel (lab test of electrolytes and urine function) and hematocrit (concentration of red blood cells). Chest x-rays are seldom obtained in patients whose history does not suggest lung disease or in non-smokers.
Patients with complicated medical histories or scheduled for general anesthesia are often sent for medical clearance by their primary care physician who is more familiar with their medical history. In certain circumstances, a patient may need clearance by a specialist such as a cardiologist, pulmonologist or endocrinologist. These physicians can assist with optimizing a patient's health and ordering specialized tests before surgery that can improve their overall course. Primary care physicians often refer patients to their surgeon and are aware that a surgery may be indicated. However, it is recommended that patients inform their primary care doctor and specialists if they are scheduled to have a procedure or surgery.
Patients should be given instructions on their medication schedule for the days prior to the surgery and on the morning of the procedure. This decision is based upon the primary care physician, surgeon and anesthesiologist's expertise and policies. Despite being instructed not to eat or drink on the day of surgery, the patient may be asked to take certain medications, particularly blood pressure medications, with a small sip of water. Conversely, certain types of blood pressure medications such as angiotensin converting enzyme inhibitors (ACEIs) or diuretics, blood thinners or oral diabetes medications are often stopped before surgery. Appropriate management and adherence to instructions can avoid cancellation of surgery and decrease the risk for complications.
Depending on the surgical setting, type of surgery, and medical history, the patient may be asked to schedule an appointment in a preoperative anesthesia clinic or receive a phone call the day prior. If a patient has questions or concerns about their anesthesia, they have the right to contact the anesthesia department and discuss them before their scheduled surgery. On the day of surgery, the patient will meet their anesthesiologist face-to-face and a thorough medical history will be attained and/or confirmed including allergies, last meal or drink, medication list, history of previous surgeries, problems with anesthesia, as well as heart, lung, brain and kidney function.
An airway exam will be performed on all patients and involves asking the patient to open their mouth and say “ahhh.” This simple exam allows the anesthesiologist to assess the ease of inserting airway devices to assist with breathing and deliver inhaled anesthetic medications in patients who are receiving a general anesthetic. In patients undergoing sedation for their procedure, information from this exam can become useful if the patient develops difficulty with breathing.
Based upon the doctor's assessment of the patient's overall health, an ASA (American Society of Anesthesiologists) score of 1-5 will be assigned. This classification system is not affected by chronological age. The score is used to assess the risk that a patient may have in the perioperative period.
The anesthesiologist will formulate and describe a plan of care and will attain consent from the patient. The patient will have the opportunity to ask specific questions about the type of anesthesia that will be administered, how their pain will be managed and what are reasonable risks.
Pain relief during or after the surgery may be provided by intravenous or oral medications. In certain circumstances, regional or neuraxial (epidural, spinal) nerve blocks with local anesthetics may be appropriate and can provide excellent pain relief, good functional outcome, reduced length of hospitalization and improved patient satisfaction when compared to other forms of pain relief.
Awareness Under Anesthesia
During the Civil War, anesthesia was provided by dipping cloth in liquid chloroform or ether and holding it over a patient's nose and mouth. There are some obvious concerns with this technique and fortunately anesthesia has come a long way since then. Today, anesthetic medications are delivered in a controlled (and more civil) manner through specialized devices to provide unconsciousness for surgery.
Over the last several years, there has been significant media coverage of “waking up” during surgery. Also known as intraoperative awareness, this implies that during a period of intended general anesthesia, the brain is aroused by stimuli that are stored in memory. Every week I have at least one patient express concern about waking up during surgery. I have to admit, I wish they were this concerned about quitting smoking, abstaining from alcohol, exercising or eating healthy. Fortunately, intraoperative awareness is extremely rare and studies have shown an estimated incidence of 0.007-0.91 percent. However, this value is not zero and our patient's concerns and fears are real.
Media coverage of this issue has resulted in the medical community proactively addressing and researching methods to prevent, identify and treat intraoperative awareness. In fact, awareness about intraoperative awareness is a good thing, especially when it is discussed factually and not sensationalized. Here are some facts every patient undergoing general anesthesia should know:
- General anesthesia is a drug-induced state that interrupts the brain's ability to process and remember information from the patient's surroundings.
- While you are asleep, your anesthesiologist utilizes sophisticated technology to deliver specific dosages of anesthetic medications (no cloth over the nose and mouth). They also carefully and vigilantly monitor your heart rate, blood pressure and breathing pattern to help gauge the depth of anesthesia. Specialized brain function monitors can assess electrical activity and possibly aid with decision-making. However, these monitors have limitations and the decision to use them should be individualized to your case.
- It is possible to remember events or conversations in the operating room before going to sleep or after awakening from your surgery. However, this does not constitute awareness under anesthesia. Additionally, some procedures are performed with sedation (e.g. colonoscopies, cataracts, biopsies) instead of general anesthesia.
- “Not giving enough” anesthesia is not the only cause of intraoperative awareness. More commonly, awareness occurs in patients who have impaired heart function, have lost a significant amount of blood, or are undergoing emergency surgeries or Cesarean sections. These patients may not be able to tolerate the blood pressure lowering effects of anesthetic medications. Your anesthesiologist may face the difficult choice between keeping the patient (or baby) alive and unharmed versus keeping them asleep. Alternatively, patients with chronic pain conditions, alcohol abuse or obesity may have higher drug requirements.
- Not all awareness is the same. It can vary from specific and vivid to dream-like memories of your surgery. Most patients who have experienced awareness did not feel pain, although some described experiencing pressure.
Doctors and researchers have shown when intraoperative awareness is identified early and appropriately managed, there is a decreased occurrence of sleep disturbances, anxiety or post-traumatic stress disorder (PTSD) and patients are less likely to avoid future medical care. If you feel you may have experienced awareness under anesthesia, alert your anesthesiologist as soon possible. He or she should obtain a detailed account of your experience and appropriately document it in your chart and report it to the hospital. When appropriate, you may be offered counseling or psychological support. You should be informed of the Anesthesia Awareness Registry and encouraged to join by calling (206) 616-2669 and requesting a paper enrollment packet.
As a patient, there are a number of things you can do that may decrease your risk of intraoperative awareness. During your preoperative interview, it is important to provide an accurate list of medications, in particular pain, anxiety, and sleep medications. Be forthright about how much alcohol you drink (or if you use any illegal drugs) and the approximate the number of cans, glasses or ounces you consume in a day or week. Anesthetic medications act on the same brain receptors as a number of these medications or alcohol and you may require higher dosages. If you have encountered, or believe you have encountered awareness under anesthesia, this should also be disclosed so your doctor can try to figure out why it happened and make specific attempts to prevent it from happening again. Be clear about what type of anesthesia you will be receiving because in some instances, sedation may be most appropriate and safest. And finally, ask the anesthesiologist if you have an increased risk.
Chronological age, in and of itself, does not increase the risk of postoperative complications. However, because patients over the age of 65 are more likely to have chronic disease as compared to younger patients, the frequency of overall complications is increased. One study of Medicare beneficiaries showed 40 percent of inpatients suffered a minor or major medical, surgical or anesthesia-related complication during hospitalization for non-cardiac surgery. Complications most frequently involve the heart, brain, lungs and kidneys. Your anesthesiologist should be able to discuss these with you after evaluating your history.
Cognitive issues, including delirium and postoperative cognitive dysfunction (POCD), are seen at a greater frequency after surgery in those who are elderly. Postoperative delirium is an acute state that is characterized by a fluctuating course, disorganized thinking and alterations in the level of consciousness with inattention. Patients may be agitated, withdrawn or have a combination of both. Delirium may present immediately after waking up from anesthesia or one to three days after. One study showed that it occurred in 13.2 percent of elderly patients following general surgical procedures but can vary depending on several factors. Treatment consists of removing potential causes, supportive care, and, if appropriate, medications. The occurrence of delirium is associated with an increase in other adverse events, length of hospital stay, need for transfer to nursing facilities instead of home and mortality.
Postoperative cognitive dysfunction (POCD) describes a deterioration of cognition after surgery and anesthesia. It is an evolving concept that is characterized by a persistent deterioration of mental performance. Studies show that POCD may be present in approximately 25 percent of elderly patients at one week following surgery and decreases to 10 percent at three months and 1 percent at two years following surgery. Diagnosis of this condition is via neuropsychological cognitive testing. It remains an active area of ongoing research and a major concern for the future given the growing elderly population and their increased need for surgical procedures. Although age appears to be the strongest predictor of POCD, additional risk factors include a longer duration of operation, limited formal education, repeat operation, postoperative infections, respiratory complications, cardiopulmonary bypass, on-pump cardiac surgery, major surgery, severe illness, orthopedic surgery, acute postoperative pain and preoperative cognitive impairment.