Anesthetic Considerations in Geriatric Patients - Pre-operative, Intraoperative, and Postoperative

Introduction:

The average lifetime has substantially expanded worldwide thanks to contemporary healthcare advancements over the past century, and older people use healthcare services at the biggest pace of development. Anesthesia is used for surgery and other operations on an increasing number of patients yearly. The safety of anesthesia for senior patients has increased due to advances in primary and perioperative care, but they still face a high risk of serious morbidity and mortality. Age raises anesthesia-related perioperative risks, correlated with several pathologic conditions that worsen morbidity and mortality. A thorough preoperative evaluation and knowledge of typical physiologic and pathologic aging can enhance patient safety and surgical results.

What Are the Anesthetic Considerations About Physiological Changes?

All major organ systems' reserves and functions decrease with age, which reduces the available reaction to sudden stress. The degree of each system's loss of function varies greatly depending on factors such as heredity, way of life, and preventative healthcare.

• Cardiovascular System: The physiological alterations of the vascular system are atherosclerosis (accumulation of lipids, cholesterol, and other materials inside and on the outermost layer of arterial walls) and the thickening of arterial walls. Geriatric people frequently have ischemic heart disease, hypertension, diabetes mellitus, and hypercholesterolemia. Eventually, aging results in a reduction in heart rate and cardiac output.

• Renal System: Renal function continuously deteriorates as people grow older. Diabetes mellitus, pre-existing renal insufficiency, and recent nephrotoxic exposure are risk factors for acute postoperative renal failure. Subclinical renal insufficiency can be brought on by sympathetic stimulation, discomfort, surgical stress, and the use of vasoconstrictive medications. Hence, urine production would be routinely monitored before, during, and after major surgery. Although, postoperative renal failure is uncommon.

• Nervous System: Aging causes a decrease in the nervous system's volume, the neurons' density, and the concentration of neurotransmitters. Among these patients, cognitive impairment, memory loss, and degenerative diseases like Parkinson's disease (a central nervous system condition that affects mobility and frequently accompanies tremors) may develop. With age, postoperative cognitive impairment gets worse. Using a regional anesthetic or a combination of general and regional anesthesia may be advantageous.

• Respiratory System: All of the respiratory system's functional capacities are decreased in geriatric people. Chest wall compliance and respiratory muscle strength decline, compromising the ability to ventilate the lungs and reducing maximum inhalation and expiration force. Geriatric people have a worsened respiratory response to hypoxemia (decreased blood oxygen level) and hypercapnia (increased level of partial pressure of CO2 or carbon dioxide). Moreover, the likelihood of developing chronic obstructive lung disease rapidly increases with age.

What Are the Types of Anesthesia Used for Elderly Patients?

The patient's medical condition, the nature and extent of the surgery, the anesthesiologist and surgeon's ability, as well as other factors, all influence the choice of anesthesia. The major type of anesthesia employed in elderly patients are:

• General Anesthesia (GA): Most general anesthetics eventually alter consciousness, lowering respiratory and cardiovascular function. Geriatric people experience hypoxemia and oxygen desaturation more frequently. Thus, proper preoxygenation is essential. Additionally, geriatric patients receive a significantly lower induction dose of the anesthetic drug. It is highly advised to titrate medications that have been administered. Those with heart problems or hypertension are advised to avoid ketamine. In elderly patients with severe cardiorespiratory conditions, GA can be preferable.

• Regional Anesthesia (RA): Regional methods can be used as a primary anesthetic approach for surgical anesthesia, or they can be used in conjunction with GA as an adjuvant technique to improve intraoperative and postoperative pain management. Moreover, RA may reduce the need for sedatives and analgesics. This method likely reduces postoperative complications after pelvic and orthopedic surgery while also maintaining spontaneous ventilation. The following are RA's claimed benefits:

1. Lower thromboembolic incidents.

2. Less confusion.

3. Decreased postoperative respiratory issues.

4. Reduction in endocrine stress related to surgery.

5. Reduction in loss of blood.

6. Effective for TURP (transurethral resection of the prostate) or carotid surgery monitoring.

• Intravenous Sedation: Geriatric individuals can benefit from safe and efficient intravenous sedation. It is typically used for minor and moderate surgical procedures, particularly in the endoscopy unit and radiology department.

What Are the Preoperative Considerations of Anesthesia in Geriatric Patients?

Preoperative considerations of anesthesia involve assessment and evaluation.

• Assessment: Geriatric patients typically have more complex preoperative evaluations than younger patients. The assessment includes a complete investigation of comorbidities, functional or physiological status, neurocognitive function, drug dependence, weakness, diet, and medicines. Eventually, it is necessary to assess history and clinical examinations in addition to the blood investigation.

• Evaluation: Preoperative evaluation for elderly people is typically not advised unless comorbid conditions are suspected. A chest film would be recommended for patients with known respiratory disorders and those who exhibit symptoms of cardiorespiratory diseases. Additionally, electrocardiograms are typically required.

What Are the Intraoperative Considerations of Anesthesia in Geriatric Patients?

The intraoperative consideration involves the following:

• Preparation of suitable pre-medication, psychological apprehension, and pre-warming of the patient's body condition.

• Elderly patients with dermatoporosis (a clinical disorder that results in chronic skin fragility) may have more difficulty obtaining appropriate and accessible intravenous fluids.

• Airway maintenance might be more challenging due to the osteoporotic mandible or lower jaw, stiffness of the temporomandibular joint, cervical spondylosis, atlanto occipital joint arthritis, and edentulous jaw or loosening of the teeth.

• The basis for fluid management should be the assessment of preoperative hydration, intraoperative losses, urine output, pulse, blood pressure, central venous pressure, and even transesophageal Doppler. Both excessive and inadequate hydration result in serious morbidity.

• The prevalence of hypothermia is decreased by forced air warmers, warmed operating rooms, covering exposed body parts (particularly the head), warming surgical wash, and warming intravenous fluids. Since oxygen demand exceeds supply during recovery, shivering may elevate oxygen demand above the respiratory threshold and result in myocardial ischemia ( When a coronary artery is partially or completely blocked by a deposit of plaques, blood flow to the heart muscle is impaired resulting in a condition called myocardial ischemia).

What Are the Postoperative Considerations of Anesthesia in Geriatric Patients?

• Appropriate nutrition plays a major role in promoting healing and rehabilitation.

• Assessment of blood glucose levels improves patient outcomes. Elderly patients have a larger prevalence of glucose intolerance, decreased liver function, and a 40 % decrease in hepatic mass, increasing the risk of both hyper and hypoglycemia.

• Due to cognitive decline, dementia, and aphasia, assessment of pain might be challenging. However, the nonverbal evaluations are aided by the patient's posture and facial expressions. Paracetamol is the most recommended drug for pain management. Whereas NSAIDS (non-steroidal anti-inflammatory drugs) increase the risk of gastrointestinal hemorrhage.

• 20 % or more of elderly patients' postoperative mortality can be attributed to acute renal failure, which can be managed with adequate fluid administration.

• The ability to increase and maintain high levels of ventilation is lower in elderly patients. Ventilatory muscle fatigue can start to manifest after 2 to 3 days of surgery. Hypoxia and hypercarbia impair brain activity, which is further decreased by opiates and anesthesia. Aging causes a decrease in protective reflexes, coughing, and swallowing. Aspirations may occur repeatedly, and injury may result. Despite these, oxygen therapy is highly required for geriatric patients.

• Acute confusion, disorientation, restlessness, agitation, fear, hallucinations, and delusions, as well as altered psychomotor activity, varying states of consciousness, and disrupted sleep-wake cycles are associated with postoperative cognitive dysfunction. These can be treated by correction of physiological parameters, effective pain medication, and engagement of geriatricians and psychogeriatricians.

• Post-operative recovery is aided by early mobilization, physiotherapy, and occupational therapy.

Conclusion:

Elderly patients are especially sensitive to the risks associated with hospitalization, anesthesia, and surgery. But age is not a sufficient reason to avoid surgery. The task of caring for elderly folks is likely to become more challenging. Geriatric patients require appropriate preoperative, intraoperative, and postoperative treatment. With these patients, a delicate balance must be struck between abnormalities in the body and those in the mind. Before using their anesthetic approaches, anesthesiologists must also be familiar with the physiological, pharmacokinetics, and pharmacodynamic variations.