June 1, 2013
Volume 77, Number 6
Perioperative Care of the Elderly: Extrapolation of Guidelines or Real Evidence?
Shamsuddin Akhtar, M.B., B.S. Committee on Geriatric Anesthesia
The National Guideline Clearinghouse has more than 2,000 guidelines on its website.1 The Guideline International Network (GIN) has more than 6,000 guideline-type documents on its website, and these documents are regularly reviewed and updated. The practice of medicine is now significantly influenced by guidelines. Based on the medical condition of concern, the guidelines vary in scope and complexity. With the current focus on evidence-based medicine, many guidelines now incorporate some assessment of evidence on which the recommendations are based. This is particularly helpful for practitioners, as it emphasizes the areas where recommendations are based on strong clinical evidence, compared to areas where there is significant lack of evidence.
While not the intention of guideline developers, unfortunately “guidelines” have become de facto “standards of care.” ASA clearly distinguishes between “Standards,” “Guidelines” and “Practice Advisories.”2 Each of the documents has different medico-legal and practice implications (as they are developed differently).2 However, other societies and organizations are not as specific when it comes to differentiating “Standards,” “Guidelines” and “Practice Advisories.” For a busy practitioner, the distinction between standards, guidelines and practice advisories can become quickly blurred, and not following the guidelines could be equated with “poor care.” This blurred distinction can directly impact institutional or practitioner ratings and regulatory issues such as pay for performance.
Guidelines and evidence-based medicine have many limitations, and detailed discussion is beyond the scope of this article.3 Many of the recommendations are not based on a high level of evidence (LOE), i.e., large randomized controlled trials in multiple populations. In reality, most recommendations are based on a low or intermediate level of evidence (retrospective studies, expert opinions).4 For example, an analysis of American Heart Association (AHA) guidelines suggested that only a small percentage of total recommendations were based on a high LOE. If one examines the American College of Cardiology/AHA guidelines for perioperative care of patients undergoing non-cardiac surgery, only 10 percent (six out of 63) of recommendations are based on LOE-A, and only five out of 16 Class I (strong, should be done) recommendations are based on LOE-A.5 All the other Class I recommendations are based on either Level B or Level C evidence (Figure 1). Complicating this issue further is interpretation of data. Experts from other specialties or organization may interpret the same data differently and as a result end up with significantly different recommendations for the same morbidities. For example, European Society of Cardiology (ESC) guidelines have a total of 92 recommendations compared to the AHA guidelines, that have 63. Half of the ESC recommendations are Class I though 50 percent are based on LOE-C (Table 1).6 Perusing through the recommendations (or executive summary) of a guideline document, it may be difficult to discern groups of patients for which there is limited or no data. The practitioner may then apply the recommendations globally, which may not be applicable and may even be potentially deleterious in certain group of patients.
It is interesting that when we think about the future advances in medicine, we often visualize an approach highlighting “individualized medicine”; however, the practice of adhering to guidelines globally “standardizes” practice and is actually counter to this approach, as it “depersonalizes” the practice of medicine. Most guidelines address clinical conditions and generalize the recommendations to a wide range of individuals; implicit recommendations for adult patients will include patients 18 years to 99 years (or even older). Extrapolating recommendations derived from younger populations to very old patients (>80 years) may not be prudent. The primary studies, on which many of the guidelines and recommendations are based, have excluded elderly, frail or debilitated patients.7,8 Expecting an intervention to have the same positive outcomes, especially in the very elderly patients who have significantly altered physiology, pharmacokinetic and pharmacodynamic profiles, may result in undesirable and inconsistent outcomes. For example, in the POISE study, 5.4 percent of the patients were older than 85 years. Using the same study design and dosing regimen for a beta-blocker, in a very elderly patient as for a younger individual, experiencing perioperative stress may have confounded the results of the study.9
Many major organizations are recognizing the limitations of their guidelines as they pertain to very elderly patients and
strongly recommended individualizing treatment regimens in older individuals.10 One document is about the manage-
ment of diabetes in older individuals.11 It clearly highlights issues that should be considered when individualizing treatment regimens in older individuals (Table 2). A similar framework can be applied more broadly. Co-morbidities and geriatric syndromes should be taken into account, including baseline cognitive dysfunction, functional impairment/frailty, depression, vision and hearing impairments, chronic pain syndromes, and persistent or neuropathic pain. Nutritional issues are frequently disregarded, and this is particularly important as elderly patients are at a significant risk for poor nutrition. Finally, age-specific aspects of pharmacotherapy should be closely considered. Age-related changes in pharmacokinetics and pharmacodynamics can have significant impact on drug dosing and their side-effects. Much lower doses need to be considered. Furthermore, complex regimens of medications, poly-pharmacy or medication burden can lead to non-adherence to treatment or significant chances of drug-drug interaction.
All of these factors complicate perioperative care of the elderly, and applying therapeutic goals that have been demonstrated
for younger patients may lead to significant deleterious effects.
It is recommended that in the perioperative period glucose be maintained less than 180-200 mg/dl to avoid osmotic diuresis and subsequent electrolyte imbalances.11 However, the authors of the guidelines recognize there are no data in the elderly population.10 It is also reasonably well established that hypoglycemia is associated with poor outcomes. Elderly patients are more vulnerable to hypoglycemia; they may also demonstrate less neuro-glycopenic symptoms and hence may develop more severe hypoglycemic levels before it is recognized. In addition, due to poor exogenous intake, glycemic regimens may have to be modified for elderly hyperglycemic patients.
Similar lack of data is evident for red blood cell (RBC) transfusion triggers in the older population. Recent guidelines by the American Association of Blood Banks (AABB) recommend hemoglobin of 7 gm/dl as a transfusion trigger in critically ill adult patients.12 However, in postoperative surgical patients, a hemoglobin concentration of 8 gm/dl is recommended, based on the FOCUS trial.13 In the presence of chest pain, orthostatic hypotension, tachycardia, unresponsiveness to fluid administration or congestive heart failure, individualized management is recommended. Though the general consensus among experts is that liberal RBC transfusion (>10 gm/dl) is unlikely to improve outcomes, the guideline developers for this target hemoglobin recognize the limitations of data. Despite analyzing many studies, they concluded that “the trial could have missed a two-fold risk of myocardial infarction associated with restrictive transfusion.” They also recognize that data advocating restrictive transfusion strategy in patients who had undergone revascularization could not be “confidently” advocated for patients with uncorrected coronary artery disease.12
Most studies investigating the role of transfusion in trauma patients have enrolled much younger patients. Most often, debilitated, multi-trauma patients have been excluded similarly. Studies involving cardiac surgery patients have included very few octogenarians (5 percent or less) (personal observation). Like glucose control, individualized patient assessment, with particular attention to co-morbidities, should guide therapy. The experts acknowledge the need for clinical trials of RBC transfusion in “elderly medical patients recovering from illnesses that result in hospitalization, hemorrhagic shock,
Many areas of perioperative management and care of the elderly need reassessment and revision. Preoperative evaluation incorporating objective measures of functional capacity, cognitive function, aspiration risk and potential drug-drug interactions may be helpful in determining risks and instituting optimal perioperative care protocols. Perioperative fluid management in the very old needs to be re-evaluated. The frequency of under- and over-hydration in this physiological marginal patient population can be disastrous and lead to prolonged hospitalization and poor outcomes.14 Similarly, perioperative nutrition should be reassessed. Functional and physiological studies are needed to guide optimal management of nutritional therapy in very elderly patients. Management strategies that have been acquired from younger, healthier populations may not be relevant or inappropriate in this patient population.
Currently, many trials registered at the Clinical Trial.gov website are involved in the management of some aspects of geriatric perioperative care/pain/intensive care. Results from these trials will be very helpful in creating new guidelines specifically in the elderly population. Another aspect that may help clinicians is the slight addition to the reporting standard in clinical trials. Reporting age distribution (< 65, 66-79, 80 and above), such as in the future publications, will also better inform readers regarding the appropriate applications of the trial results in elderly population. Future research must allow and account for medical complexity, with multiple co-morbidities and heterogeneity of geriatric patients, if we are to significantly advance evidence-based perioperative management of the elderly population.
Shamsuddin Akhtar M.B., B.S. is an
Associate Professor, Director of
Medical Education, Secretary,
Society for Advancement of Geriatric Anesthesia (SAGA), Yale University School of Medicine, New Haven, Connecticut.
1. National Guideline Clearinghous. http://guideline.gov/. Accessed April 2, 2013
2. Guidelines International Network. http://www.g-i-n.net/. Accessed April 2, 2013
3. Howick JH. The Philosophy of Evidence-Based Medicine. Chichester, UK: Wiley-Blacwell, BMJ Books; 2011.
4. Tricoci P, Allen JM, Kramer JM, Califf RM, Smith SC Jr. Scientific evidence underlying the ACC/AHA clinical practice guidelines. JAMA. 2009;301(8): 831-841.
5. Richards KL, Ferrara J, Kurup V, Myslajek T, Hines RL, Akhtar S. AHA guidelines 1996-2009: increase in evidence or getting lost in it? [abstract A080]. Presented at: Anesthesiology 2011; October 15, 2011; Chicago, IL. http://www.asaabstracts.com/strands/asaabstracts/searchArticle.htm;jsessionid=2DC322A8E8719F74191A892C908F5F2D?index=1&highlight=true&highlightcolor=0&bold=true&italic=false. Accessed April 11, 2013.
6. Ferrara J, Richards K, Kurup V, Myslajek T, Hines R, Akhtar S. ESC vs AHA guidelines: a tale of two continents [abstract A1651]. Presented at: Anesthesiology 2011; October 19, 2011; Chicago, IL. http://www.asaabstracts.com/strands/asaabstracts/searchArticle.htm;jsessionid=2DC322A8E8719F74191A892C908F5F2D?index=0&highlight=true&highlightcolor=0&bold=true&italic=false. Accessed April 11, 2013.
7. Alexander KP, Newby LK, Armstrong PW, et al. Acute coronary care in the elderly, part II: ST-segment-elevation myocardial infarction: a scientific statement for healthcare professionals from the American Heart Association Council on Clinical Cardiology: in collaboration with the Society of Geriatric Cardiology. Circulation. 2007;115(19):2570-2589.
8. Alexander KP, Newby LK, Cannon CP, et al. Acute coronary care in the elderly, Part I: non-ST-segment-elevation acute coronary syndromes: a scientific statement for healthcare professionals from the American Heart Association Council on Clinical Cardiology: in collaboration with the Society of Geriatric Cardiology. Circulation. 2007;115(19):2549-2569
9. Devereaux PJ, Xavier D, Pogue J, et al.; POISE (PeriOperative ISchemic Evaluation) Investigators. Characteristics and short-term prognosis of perioperative myocardial infarction in patients undergoing noncardiac surgery: a cohort study. Ann Intern Med. 2011;154(8):523-528.
10. American Diabetes Association. Standards of medical care in diabetes--2013. Diabetes Care. 2013;36(suppl 1):S11-S66.
11. Kirkman MS, Briscoe VJ, Clark N, et al. Diabetes in older adults. Diabetes Care. 2012;35(12):2650-2664.
12. Carson JL, Grossman BJ, Kleinman S, et al.; Clinical Transfusion Medicine Committee of the AABB. Red blood cell transfusion: a clinical practice guideline from the AABB*. Ann Intern Med. 2012;157(1):49-58.
13. Carson JL, Terrin ML, Noveck H, et al.; FOCUS Investigators. Liberal or restrictive transfusion in high-risk patients after hip surgery.
N Engl J Med. 2011;365(26):2453-2462.
14. Soni N. British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients (GIFTASUP): Cassandra’s view. Anaesthesia. 2009;64(3):235-238