Admissions of geriatric patients to intensive care units (ICUs) are becoming increasingly common and are responsible for increasing healthcare costs.
Older adults present to the ICU in two different ways: acutely and electively. Outcomes after elective ICU admission seem to be better: 1-year mortality for unscheduled surgery was 67 percent, and the 1-year mortality for emergent medical admissions was 80 percent.
The purpose of preoperative evaluation in elderly patients is to document a baseline functional status, stratify risk so that modifiable risk factors can be addressed, optimize patients prior to surgery where possible, and recognize postoperative changes objectively.
Intraoperative management for older adults should take into account the preoperative concerns: lower doses of hypnotic, sedative, and analgesic agents due to the increased sensitivity of the elderly brain; decreased rate of redistribution leading to higher comparative blood levels of drug; and decreased metabolism of drug by the liver or kidney, leading to a longer drug half-life.
Preoperative frailty has been strongly correlated with postoperative outcomes in the elderly patients, and a strong argument can be made for obtaining frailty scores preoperatively to predict perioperative outcomes and guide care in the ICU (especially withholding or withdrawing life support).
The rapid growth of the population older than 65 years of age and its impact on healthcare is a well-recognized fact. Critical care services are not immune to this phenomenon; in fact, admissions of geriatric patients to intensive care units (ICUs) are increasingly common. When examining ICU admissions between1992–96 and 2002–6, a Dutch institution reported a 33 percent increase in admissions of patients older than age 75 . Similarly, data from 57 ICUs in Australia and New Zealand showed a 6 percent increase per year in ICU admissions between 2000 and 2005 of patients older than 80 years of age . This segment of the population represented 14 percent of all ICU admissions in this cohort. In the United States, approximately 42 to 52 percent of ICU admissions are older adult patients, with 60 percent of all ICU days attributed to this group . Additionally, 11 percent of Medicare recipients spend an average of 8 days in the ICU during the final 6 months of their lives, and about 40 percent of Medicare recipients who die are admitted to the ICU during their terminal illness . These ICU stays represent approximately 25 percent of total Medicare expenditures . Teno et al. published data showing increases in ICU use among Medicare beneficiaries in the last 30 days of life, from 24.3 percent in 2000, to 26.3 percent in 2005, and 29.2 percent in 2009, despite a decrease in the mortality rate in acute care hospitals . Considering that hospital stays that involve ICU services are two and a half times costlier than those without ($61,800 versus $25,200) , it is easy to infer the financial impact of the increasing number of elderly adults requiring critical care services. An additional challenge is the relative decrease in ICU beds available per capita, from 193.2 ICU beds per 100,000 elderly persons to 189.4 beds per 100,000 elderly persons, as the segment of those over 65 years continues to grow .
Older adults present to the ICU in two different ways: acutely and electively. An acute presentation encompasses most medical admissions as well as acute unplanned surgical admissions, e.g., trauma and surgical catastrophes. Elective, or planned, ICU admissions are generally related to surgical interventions. Outcomes in this latter group seem to be better than in the former. One study reported that postsurgical admissions had an ICU mortality of 12 percent and a hospital mortality of 25 percent, with 72 percent of those who survived being discharged home . Similarly, another study found that 57 percent of elderly patients who underwent elective surgery were still living at 1 year after surgery . In contrast, older patients who required emergency surgery had an 89 percent mortality rate, and those admitted for acute medical issues had a 90 percent mortality rate . These findings are consistent with another study that reported that the 1-year mortality for unscheduled surgery was 67 percent and the 1-year mortality for emergent medical admissions was 80 percent .
Although survival after elective surgery is better than survival after emergent surgery or ICU admission for geriatric patients, unfortunately, the perioperative outcomes of this patient population are still significantly worse than those of younger adults. In a prospective observational study of 1,064 patients undergoing noncardiac surgery, those older than 65 years had a 1-year mortality rate of 10.3 percent – almost double that of younger adults (5.5 percent) . These findings are no different from those of an epidemiologic study looking at surgical mortality in the United States, in which mortality increases dramatically for those older than 65 years of age . A 2002–5 review of the Veterans Affairs National Surgical Quality Improvement Program (NSQIP) database examining 7,696 surgeries showed an overall 28 percent morbidity rate and 2.3 percent mortality rate, but in those older than 80 years of age the morbidity rate was 51 percent and the mortality rate was 7 percent .
Complications are clearly associated with mortality; very likely, an elderly patient may survive surgery but succumb to postoperative complications. Perioperative complications in older adults and their relationship with mortality have been well identified. Central nervous system (CNS) and cardiac, pulmonary, and renal systems seem to be the common systems in which complications have the greatest impact on outcomes [13–15]. A study completed at NSQIP of patients who had noncardiac surgery between 1991 and 1999 showed that in those age 80 years or older, 20 percent had one or more postoperative complications . Patients who suffered complications had a higher 30-day mortality than those who did not (26 versus 4 percent, P < 0.001) .
Wunsch et al. analyzed data to determine the 3-year outcomes of 35,308 ICU Medicare beneficiaries who survived intensive care. Patients who survived the ICU had a higher 3-year mortality (39.5 percent, n = 13,950) than hospital controls (34.5 percent, n = 12,173, adjusted hazard ratio [AHR] 1.07, 95 percent confidence interval [CI] 1.04–1.10, p < 0.001) and general controls (14.9 percent, n = 5,266, AHR 2.39, 95% CI 2.31–2.48, p <0.001) . Interestingly, survivors who did not receive mechanical ventilation had minimal increased risk compared with hospital controls (3-year mortality 38.3 percent, n = 12,716 versus 34.6 percent, n = 11,470, respectively, AHR 1.04, 95% CI 1.02–1.07), but those who underwent mechanical ventilation had substantially increased mortality (57.6 percent, n = 1,234 ICU survivors versus 32.8 percent, n = 703 hospital controls, AHR 1.56, 95% CI 1.40–1.73), with risk concentrated in the 6 months after the quarter of hospital discharge (6-month mortality 30.1 percent, n = 645 for those receiving mechanical ventilation versus 9.6 percent, n = 206 for hospital controls, AHR 2.26, 95% CI 1.90–2.69) .
Examining long-term outcomes, however, should not be limited to mortality. Quality of life (QoL) is also enormously important for patients and their families. Dependency in activities of daily living (ADLs) has been associated with perioperative complications in the elderly . Complications involving the CNS and cardiac, pulmonary, and renal systems have great impact on outcomes and result in unplanned admissions to the ICU [13–15]. It is also important to note that patients who survive the ICU and are discharged to a skilled care facility have higher 6-month mortality (24.1 percent for ICU survivors and hospital controls discharged to a skilled care facility versus 7.5 percent for ICU survivors and hospital controls discharged home, AHR, 2.62, 95% CI 2.50–2.74, p < 0.001 for ICU survivors and hospital controls combined) .
This growing elderly population that consumes a large segment of healthcare resources and is prone to suboptimal outcomes fits the paradigm of the American Society of Anesthesiologists’ (ASA) Perioperative Surgical Home (PSH) model. This initiative is framed under the Institute for Healthcare Improvement (IHI) Triple Aim, whose goals are to enhance the patient’s experience of care (quality and satisfaction) while reducing the per capita cost of healthcare [17,18]. The PSH is therefore a patient-centric, team-based model of care that emphasizes value, patient satisfaction, and reduced costs [19,20].
The key element in the conceptual frame of the PSH model is to minimize variability in perioperative care . Lessons from organization management demonstrate that variability in practice increases the likelihood for errors and complications. It is suggested that variability can be reduced by ensuring continuity of care and treating the entire perioperative episode of care as one continuum rather than discrete preoperative, intraoperative, postoperative, and postdischarge episodes . It appears that aiming for a better coordination in care for older adults could improve outcomes and decrease costs by minimizing complications that might lead to critical illness in this growing patient population .
In 2012, the American College of Surgeons (ACS) NSQIP and American Geriatrics Society (AGS) published best practice guidelines focusing on the optimal preoperative assessment of geriatric surgical patients . These guidelines detail a comprehensive and evidence-based preoperative assessment with the goal of optimizing patients prior to surgery. Medical optimization is certainly a possibility for geriatric patients who present for elective surgeries with planned postoperative ICU admission. In contrast, the ability to optimize a geriatric patient after trauma or an unexpected surgical complication are more limited, but some degree of preoperative assessment may still be possible and is helpful for prognosis and guiding intra- and postoperative therapy. The ACS NSQIP/AGS best practice guidelines will be reviewed next, updated for more recent developments.
For the preoperative neuropsychiatric evaluation of geriatric patients, the guidelines recommend identifying risk factors for the development of delirium, assessing cognitive ability and capacity, and screening for depression as well as alcohol and other drug abuse or dependence . The purpose of this evaluation is to document a baseline functional status, stratify risk so that modifiable risk factors can be addressed, optimize patients prior to surgery where possible, and ensure that postoperative changes are recognized objectively and treated.
Delirium is the most common complication in geriatric surgical patients, affecting up to 50 percent of older postoperative patients [24,25]. The guidelines recommend that risk factors for delirium be identified, and for patients at risk for postoperative delirium, the use of benzodiazepines and antihistamines should be avoided [23,26]. Risk factors for delirium are summarized in Table 13.1, with the following six risk factors highlighted by ACS NSQIP/AGS and Society of Critical Care Medicine (SCCM) guidelines: preexisting dementia, coma, history of hypertension, history of alcoholism, a high severity of illness at admission, and benzodiazepine use [23,26].
|Cognitive and behavioral disorders|
|Disease or illness related|
To assess cognitive ability and screen for cognitive impairment, in addition to reviewing medical records and, when possible, interviewing those familiar with the patient (e.g., family), the Mini-Cog and clock-drawing tests have emerged as rapid, effective, and recommended screening tools [23,25,27] (Table 13.2 and Figure 13.1). Preoperative cognitive testing is important to establish a baseline with which postoperative status can be compared. Additionally, patients with impairment can be identified and potentially further evaluated or referred for specialist workup. Finally, evidence of cognitive impairment is important in determining the patient’s functional capacity and ability to follow medication regimen and maintain quality of life.
Figure 13.1 Mini-Cog scoring algorithm (www.ncbi.nlm.nih.gov/pubmed/11113982).
The assessment of a patient’s competence, or their decision-making capacity, is recommended by the guidelines and is important in determining a patient’s ability to provide informed consent for surgery and anesthesia . Legal criteria for capacity are defined as the ability to demonstrate understanding, appreciation, reasoning, and choice as they pertain to medical decisions. That is, a patient must be able to understand the information communicated to them, appreciate their clinical situation and consequences, reason through various options, and choose from among the options. A discussion of approaches to capacity assessment is beyond the scope of this chapter but is covered in an excellent review .
Screening for depression and alcohol or substance dependence or abuse is recommended by the guidelines and can be accomplished via the use of validated questionnaires . The Patient Health Questionnaire-2 (PHQ-2) is a simple, rapid, and recommended tool to screen for depression  (Table 13.3); patients screening positive can be referred for further evaluation or workup. Screening for alcohol or substance dependence or abuse can be accomplished through the CAGE (Cut down, Annoyed, Guilty, Eye-opener) questionnaire, with any “yes” answer considered a positive result [23,25]. Patients screening positive for substance dependence or abuse should be considered for perioperative withdrawal prophylaxis, perioperative vitamin supplementation (e.g., thiamine and folic acid), and – time permitting – referral for abstinence or detoxification programs .