Preoperative care: risk assessment

One of the central tenets of perioperative planning for the patient is to weigh the potential harm against the benefit of the operation in terms of return to acceptable function and/or alleviation of suffering. This tenets holds in the elective as well as the acute setting. Risk assessment involves a thorough evaluation of the patient’s functional and physical status, as well as elicitation of patient centered goals of therapy, ideally in partnership with the patient’s primary care provider.

Traditional risk assessment has focused on cardiac risk and mortality outcomes. For instance, the Revised Cardiac Index, published in 1999 by Lee et al. in Circulation, is part of the American Heart Association and American College of Cardiology guidelines and is used to predict perioperative cardiac complications.[6] Such risk assessment has also assisted with potential risk modification, for instance with the use of perioperative blockade. The American College of Surgeons National Surgery Quality Improvement Program developed a risk calculator to estimate morbidity and mortality for a patient undergoing surgery. This calculator takes into account many relevant factors regarding the geriatric population such as functional and nutritional status. This online tool is available at http://riskcalculator.facs.org/PatientInfo/PatientInfo. No one calculator has been clearly deemed superior; therefore, most physicians utilize these different tools to obtain an overall idea of the patient’s perioperative risk.

Refined preoperative assessment tools and the use of frailty measures have led to better insight into the difference between chronologic and physiologic age. Along with this shift has come focus not only on mortality and complications as outcomes, but also on functional status, discharge disposition, rehospitalization, and other quality-of-life measures. Some newly identified risk predictors are relatively simple. For example, a positive history of falls in the past six months in elderly patients undergoing colorectal surgery predicts increased complications and readmissions, as well as increased rates of discharge to a care facility instead of home.[7] The evaluation of sarcopenia based on computed tomography imaging of the psoas muscle is another novel method of assessment of frailty and risk. Sarcopenia, or loss of muscle mass, appears to be a predictor of increased physiologic age, frailty, loss of independence following surgery or injury, and increased mortality.[8, 9]

In addition to these uncomplicated approaches, a multidimensional comprehensive geriatric assessment (CGA) performed by a multi-disciplinary geriatric team is recommended. Such a program has been demonstrated to predict adverse outcomes postoperatively in the geriatric population undergoing elective procedures.[10] The CGA includes: cognitive assessment, depression screening, consideration of risk factors for delirium, alcohol and drug use, cardiopulmonary evaluation, burden of comorbidity, polypharmacy assessment, physical function and history of falls, frailty, nutritional assessment, social support and goals of therapy.[10–12] Ideally, this work in preoperative assessment will allow not only appropriate selection of patients but will also lead to proactive risk modification and improved outcomes for all geriatric patients in need of surgical care.[13]

Medications assessment

Certainly medication assessment in the surgical geriatric patient is critical. Evaluation of the need for anticoagulation in the perioperative period is an essential part of medication assessment. Vitamin K antagonists such as warfarin are usually held five days preoperatively. However, in patients who are at high risk for thromboembolism, anticoagulation should be bridged instead of completely stopped.[14] Urgent procedures require reversal of these agents with the administration of vitamin K if a 12-hour delay is acceptable, or with fresh frozen plasma or a prothrombin concentrate if more urgent intervention is required. Other oral anticoagulants such as dabigatran, rivaroxaban, and apixaban, have shorter half-lives but may not be easily reversed in cases of emergency. Antiplatelet therapies such as clopidogrel are held seven days prior to surgery. Continuation of aspirin has been controversial. However, holding aspirin preoperatively has been associated with withdrawal syndrome and increased risk of thromboembolism.[15] It is advised that aspirin be continued perioperatively. Similarly, for some patients in the period of high risk for cardiac stent thrombosis, continuation of all antiplatelet therapy through the perioperative period may be warranted.

The patient will often be NPO at midnight for surgery the next day, therefore it is crucial to know which medications to continue and which to withhold on the day of surgery. Medications that should be continued include beta blockers, anti-arrhythmics, asthma medications, gastroesophageal reflux therapies, and statins. It appears quite important to continue beta blockers since their withdrawal perioperatively has been shown to increase morbidity and mortality.[16] Continuation of angiotensin converting enzyme (ACE) inhibitors is controversial as their continuation has been associated with improved outcomes in cardiac surgery patients, but their use has also been associated with severe intraoperative refractory hypotension. Medications that should be held the day of surgery include insulin, oral hypoglycemic agents, and diuretics unless prescribed for congestive heart failure.

Preoperative communication

An in-depth discussion of goals of care is paramount to ensure the surgeon, the patient, and his or her family are in agreement. At times, communication with the patient themselves may be complicated because of dementia or delirium, reinforcing the critical importance of involving family early on in the decision-making process.[17] A goal-oriented approach may be recommended over the usual disease/procedure-oriented method, especially for elderly patients with multiple medical problems facing the end of life. The patient and her social support figures are the experts in the patient’s goals, values, expectations, and hopes. The surgeon caring for this population needs to be well versed in the variety of options to help choose the best treatment plans that maximize the likelihood of meeting those goals. In certain situations, more conservative treatments may be associated with a better quality of life.[18]

Older patients naturally are more likely to have do not resuscitate (DNR) orders and other limitations placed on burdensome treatments, often outlined in advanced directives. Literature exists concerning the effect of DNR orders on outcomes as well as the surgical care. For example Saager, et al. found that preexisting DNR orders are not associated with increased postoperative morbidity at 30 days in a cohort of surgical patients from the American College of Surgeons National Surgery Quality Improvement Program database.[19] However, Kazaure and colleagues found that DNR orders were an independent risk factor for 30-day mortality in a cohort of patients from the same database.[20] Unfortunately, at times a DNR order is conflated with less care and patients with such orders may be afforded less opportunities for certain types of interventions. It is important to review such orders explicitly in the preoperative planning. DNR orders or other limitations to life-prolonging therapies need not be a barrier to consideration of operative intervention especially for procedures aimed for symptom relief. Most societies, including the American College of Surgeons, recommend a practice of required reconsideration, in which exploration of the goals and values associated with a DNR order inform a careful discussion to evaluate whether to rescind or leave in effect the DNR order. If the order is rescinded at the time of the operation, a clearly defined perioperative time period should be established.[21]

Postoperative care: prevention and management of complications, disposition

Postoperative complications in the elderly population are responsible for significant morbidity, mortality, and functional derangements. The most common complications that occur postoperatively in geriatric surgery are neurologic, cardiac, and pulmonary. Postoperative delirium is the number one neurologic complication, with rates reported between 15% and 53% of general patients and up to 80% for patients in the intensive care unit.[22] Importantly, the development of delirium is independently associated with poor outcomes. Some risk factors associated with delirium include cognitive impairment, sleep deprivation, immobility, visual impairment, hearing impairment, and dehydration. Implementing certain protocols such as orienting the patient throughout the day, using noise reduction strategies at night, encouraging early physical therapy and ambulation, reinstituting visual and hearing aids immediately postoperatively, and ensuring adequate oral intake have been shown to decrease the incidence of delirium.[22] Other factors associated with increased risk of delirium include inadequate pain control, electrolyte abnormalities, and opioid use.[23] Adequate pain control can be complicated in the elderly secondary to decreased renal and hepatic function, drug–drug interactions, and cognitive impairment. Medications without significant effects on mental status such as NSAIDs and IV acetaminophen are preferred. However, opiates should be used if necessary for pain control. Clinical status should be carefully monitored for any signs of sedation that could signal respiratory depression. To avoid adverse side effects, the rule “start low and go slow” should be employed for narcotic dosing.[24] Regional blocks preoperatively can decrease postoperative pain medication use and should be done if appropriate. Neuraxial blockades have also been shown to improve survival and decrease complications such as venous thromboembolism and respiratory depression.[25]

Although age has not been shown to be an independent risk factor in cardiac postoperative care, acute myocardial infarction has a higher mortality in the elderly population. As previously discussed, patients who were on beta blockers preoperatively for ACCF/AHA guideline indications should be continued on them postoperatively.[16] Careful attention to fluid balance is critical in avoiding both cardiac and pulmonary insufficiency in the perioperative period. It is often too easy to tip the scale in either direction in patients, for example, with aortic stenosis or diastolic dysfunction. Unfortunately, tools for assessing intravascular volume remain inadequate, and attention to weight, intakes and outputs, and physical assessment remain important tools.

Pulmonary complications have been shown to strongly correlate with age. Patients 60–69 years of age experience twice the number of pulmonary complications of those less than 60 years, whereas patients aged 70–79 have three times as many complications. Risk factors include the use of long-acting neuromuscular blockage, decreased lung expansion, surgery close to the diaphragm, and aspiration. To ensure lung expansion and avoid shallow breathing, early mobilization, adequate pain control, and incentive spirometry should be employed. Elderly patients are also at a higher risk of aspiration due to weakened oropharyngeal reflexes, which can be compounded by swallowing disorders. Appropriate aspiration precautions should be practiced and sedation avoided.

Hypothermia has been associated with many postoperative events such as cardiovascular complications and surgical site infection. The elderly are more prone to developing hypothermia due to physiologic changes including impaired central thermoregulation, vasoconstriction, and decreased metabolic activity.[23] Therefore, aggressive thermoregulation with the use of warming devices should be carried out perioperatively.

Polypharmacy is also a significant cause of post-surgical complications in the elderly with over 25% of hospitalized geriatric patients receiving an inappropriate medication.[26] The START and STOPP criteria or Beer’s criteria can be used to determine appropriateness of a patient’s medical regimen.[27, 28] These criteria have been utilized to assess for medications that may increase the risk of postoperative complications as well as medications that may result in the increased risk of falls and traumatic injuries.

Unlike the younger population, elderly patients are less likely to be discharged home after surgery. Both preoperative risk factors and post-surgical complications play a role in disposition. For example, the incidence of being discharged to a facility after a minor surgery was 0.8% in nonfrail and 17.4% in the frail. The incidence after major surgery was 2.9% in nonfrail versus 42.11% in frail patients.[29] Interdisciplinary team efforts to facilitate early mobilization may improve functional independence in this population.