critical care, geriatric patients, glycemic control



  1. Humbert, Jennifer BSN, RN
  2. Gallagher, Kendra BSN, RN
  3. Gabbay, Robert MD, PhD
  4. Dellasega, Cheryl PhD, RN


Tight glucose control can significantly improve outcomes of critically ill geriatric patients in the critical care unit (CCU). In the past, blood glucose levels were managed by a point-of-care testing every 4 to 6 hours and using a sliding scale of insulin therapy. This article explores the need for more intensive intravenous insulin therapies. Studies have shown that patient outcomes improve by having a specific set of standing orders, a well-defined algorithm, and empowering the CCU nurses with these tools. Methods for initiating intensive intravenous insulin therapies are discussed along with some of the biggest challenges faced by CCU nurses at the bedside.


Article Content

DIABETES is the fourth most common diagnosis in hospitalized patients, which creates a need for nurses to provide more complex care, especially to older patients who have multiple comorbidities.1 Inpatient days are 43.9% higher for patients of all ages with a diagnosis of diabetes than those without.2 In the past, the importance of glycemic control was not a primary focus in nursing care of patients with critical illness, in part because of a lack of evidence or documented studies proving the need for tighter glycemic control.3 This is no longer the case: recent studies show that improved glycemic control reduces mortality, morbidity, and cost of care, which results in fewer inpatient complications and fewer rehospitalizations.


These are crucial issues for acute care nurses providing care for elderly patients who are primarily older than 65 years with multiple conditions, and at an increased risk of long length of stays and rapid readmissions.2 Statistics from the Center for Disease Control and Prevention state that of patients 75 years and older, approximately 64% have a diagnosis of diabetes, making them twice as having diabetes as those aged 45 years and younger.4


From 1991 to 2001, there was a 48% increase in a diagnosis of diabetes among hospitalized patients,5 and 17 million hospital days were attributed to diabetes with inpatient cost soaring to $40.3 billion.2 The annual per capita cost for care of a patient with diabetes is $6309 and for a patient without diabetes is $1289.2


Some reasons for these cost increases include more frequent hospitalizations, longer hospital stays, more procedures, multiple medications, chronic complications, nosocomial infections, atherosclerotic disease, and the need for more intensive nursing care. In addition to these factors, recent studies have shown that hyperglycemia in hospitalized patients is an independent risk factor for adverse outcomes.2 Because hyperglycemia strongly influences patient outcomes, if no changes are made in the current system, these issues will continue to grow.


By improving the glycemic control of critically ill geriatric patient, mortality, morbidity, and cost of care can be reduced, resulting in fewer inpatient complications and fewer rehospitalizations. Nurses play a key role in glycemic control and can have a positive impact on these important cost- and health-related outcomes.



In 2001, The New England Journal of Medicine published a landmark study that focused on intensive insulin therapy in patients with critical illness. Van den Berghe et al6 evaluated whether the normalization of blood glucose levels with insulin therapy improved the prognosis in patients with hyperglycemia and insulin resistance in a critical care setting. The randomized control trial was designed so that when patients were admitted to the critical care unit (CCU), they were randomly assigned to receive either intensive insulin therapy (IIT) or conventional treatment. Intensive treatment was defined as maintenance of blood glucose levels between 80 and 110 mg/dL, which was achieved by following a standing orders set and a titration algorithm.6Conventional treatment was defined as the standard practice of maintaining blood glucose levels between 180 and 200 mg/dL.


Over a 12-month period, 1548 patients were enrolled. The mean age of these patients was 63.4 years, with a standard deviation of 13.6.6 The study findings revealed that mortality during intensive care was reduced from 8.0% with conventional treatment to 4.6% with intensive insulin therapy. Overall hospital mortality was reduced by 34%, blood stream infections by 46%, acute renal failure requiring dialysis or hemofiltration by 41%, the median number of red cell transfusions by 50%, and critical illness polyneuropathy by 44%, and patients receiving intensive insulin therapy were less likely to require prolonged mechanical ventilation and intensive care.6


Another study conducted in 2006 in medical and surgical intensive care units of a community hospital evaluated the safety and effectiveness of a nurse-managed intensive insulin infusion protocol.7 The nurses in this study titrated insulin infusions according to a standing orders set and followed a well-defined algorithm, which included frequent blood glucose monitoring. The results affected morbidity and mortality when a glucose target range of 91 to 130 mg/dL was used. The control group of 143 patients had their insulin infusions regulated by a physician alone (control group), and 70 patients in the treatment group received infusion dosages adjusted by nurses according to a given protocol (treatment group).


Blood glucose target ranges were achieved in 34% of the protocol group and 23% of the control group, respectively. Once the target range glucose level was met, 43% of the protocol group remained in the range, while only 29% of the control group maintained the target range. The protocol group had an overall mortality of 27% in comparison with the control group mortality of 32%, along with reduced length of stay and less time on mechanical ventilation. Hypoglycemic episodes were not significantly different between the two groups. The study concluded that nurse-managed insulin infusion protocols could improve blood glucose control without significant hypoglycemia.7


The question inevitably raised when changes to existing healthcare practices are proposed is: What will it cost? The American Association of Clinical Endocrinologists and the American Diabetes Association suggest that intensive insulin therapy is an investment.3 A study that involved patients with coronary artery bypass graft surgery showed that for every 50 mg/dL increase in blood glucose level, there was an additional 0.76-day length of stay. This increased the cost per patient by $2824.3 Another study revealed that intensive insulin therapies used in the CCU resulted in an estimated yearly cost savings of $40 000 per CCU bed.3 Another study at the Penn State Milton S. Hershey Medical Center evaluated the cost of using an intravenous glucose infusion protocol and endocrinology consultations on patients after coronary artery bypass graft surgery. The researchers noted that the intervention was revenue neutral despite an increase in blood glucose monitoring and insulin cost.8



The evidence clearly shows the need for a tight glycemic control in patients with critical illness of any age, but especially among the elderly who usually have multiple comorbidities. Aging is among the many factors that lead to increased insulin resistance.9 Advanced age predisposes geriatric patients to hypoglycemia, and therefore makes the challenge to maintain target glucose levels time consuming and complex for nurses.9 Failure to normalize blood glucose levels in an already at-risk patient population further predisposes the geriatric patients to infection, polyneuropathy, multiorgan failure, and ultimately death.10 Understanding this situation is important because the elderly (>65 years) account for 42% to 52% of intensive care unit admissions and 60% of all CCU days.11


Glycemic control is a preventive therapy. Multiple studies demonstrated that glycemic control is associated with decreased CCU mortality, and that nondiabetic patients with hyperglycemia have a 16% increased risk for in-hospital mortality.12 Current practices for critically ill geriatric patients in the CCU typically involve using a traditional sliding scale of insulin therapy with blood glucose monitoring every 4 to 6 hours. Van den Berghe et al6 and Quinn et al7 provide evidence that supports best practice as intensive IITs.


Implementing IIT requires a collaborative team approach. Support is needed from all members of the healthcare team including physicians, nurses, laboratory personnel, research teams, and third party payers. As the professionals who spend the maximum time with hospitalized patients, nurses are key to the success of collaborative effort. Some common barriers to initiating IITs include (1) determination of who is responsible for doing point-of-care testing: the nurse, laboratory technicians, or nursing assistants; (2) inaccuracy of capillary tests owing to shock, hypoxia, or dehydration; (3) adequacy of staffing to provide the 1:2 nurse/patient ratios needed to implement IIT; (4) access to blood glucose meters in the hospital setting; and (5) fears about hypoglycemia secondary to IIT (Table 1). In many situations, the most significant barrier is acceptance. Educating a multidisciplinary team on the importance of IIT and having its members implement the protocol as best practice presents a major challenge for CCU nurses. It is important to remember that failure to treat hyperglycemia is an error of omission; it is unsafe and ultimately can lead to death.3 Advanced age is not a criterion for intensive insulin therapy.

Table 1 - Click to enlarge in new windowTable 1. Common barriers to acceptance of intravenous insulin therapy

Indications for IIT include diabetic ketoacidosis, nonketotic hyperosmolar state, critical care illness after the cardiac surgery, myocardial infarction or cardiogenic shock, and NPO status in type I diabetes. In addition, patients whose glucose levels are exacerbated by high-dose glucocortiticoid therapy, or those in the perioperative period and those on total parenteral nutrition therapies, are also candidates for IIT.


Nursing care is vital to effective glucose management in any setting. Van den Berghe et al6 identified several acute care issues that nurses should be cognizant of: (1) insulin requirements are highest and most variable during the first 6 hours of intensive care; (2) between days 7 and 12, insulin requirements decrease by 40% on stable energy intake; (3) achievement and maintenance of blood glucose level of less than 110 mg/dL are possible in all patients treated with IIT, and (4) no serious hypoglycemic events were reported in spite of the fact that this outcome is considered a feared complication on IIT.


The American College of Endocrinology and the American Diabetes Association consensus statement notes that successful implementation of IIT includes having adequate support from hospital administration, especially financial commitment to fully implement the process.3 There is also the need to support the professional nursing staff through education, adequate supplies, and sufficient staffing to safely administer IIT. The interdisciplinary team members all need to be familiar with and follow a well-defined policy and algorithm.


One standard that is frequently used for reference is the Portland Protocol.13 This well-defined orders set spells out who is responsible for implementing IIT, which patients are to be placed on the protocol, how to mix the insulin bags, how to monitor a patient receiving IIT, how to adjust the rate of infusion, duration, what happens when a patient is transferred, and how to stop the infusion. When IIT is adopted, there is a need for a multidisciplinary steering committee to promote the need and acceptance of IIT.3 Nurses are champions for the program because they will be on the front line of administering it.


The challenges that may confront CCU nurses caring for elderly patients receiving IIT include difficulty assessing hyper- and hypoglycemia (Table 2). Hypoglycemia may be difficult to assess due to altered response of the autonomic nervous system in the geriatric population. Elderly patients tend to have increased incidence of delirium in the CCU setting, which can mask the signs and symptoms of hypoglycemia.11 When assessing for hyperglycemia in the elderly, the typical symptoms may not be exhibited because of an increase in the renal threshold for glucose.8 Polypharmacy and its associated complications can also affect elderly CCU patients due in large part to alterations in metabolism that affect how they respond to medications.14

Table 2 - Click to enlarge in new windowTable 2. Challenges in assessing hyper/ hypoglycemia in elderly patients

It is important to remember that the elderly are predisposed to the same macro- and microvascular complications as younger diabetic patients. Studies show there is an increased prevalence of these complications in the elderly.15 One of the biggest challenges to nurses in the CCU setting is that the American Diabetes Association does not have set standards for glycemic control specific to the geriatric population. Therefore, the goals become prevention of hypo- and hyperglycemia along with the prevention of long-term complications.16



Hyperglycemia leads to increased cost and poorer patient health-related outcomes, which is a concern for nurses, who typically have the most responsibility for patient care. As patient advocates, nurses should take a leadership role in educating others about the importance of glucose regulation for the elderly and other patients with critical illness. With the support of all nurses, implementation of IIT protocols is more likely to happen. A convincing argument for IIT is that the protocol is cost-effective, improves patient outcomes, and reduces demands on nurses. By being the champions for best practice in glucose regulation, nurses in the CCU are empowered to make autonomous decisions and provide state-of-the-art care for their patients.




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