Management of Patients with Diabetes in the Intensive Care Unit

What Is Known and What Is Not Known

Despite recognition of diabetes mellitus (DM) as a risk factor for acute kidney injury (AKI), the inclusion of DM in stratifying patients within large databases is not consistent. In reviewing several papers describing the risk, injury, failure, loss, and end-stage renal disease (RIFLE) and Acute Physiology And Chronic Health Evaluation (APACHE) scores and the use of new biomarkers for AKI, we were surprised to find that DM was not identified overtly in the demographics of any of the published studies. Nonetheless, in other studies, DM is a well-recognized risk factor for AKI, and the coexistence of DM in the critical care population raises unique management challenges for clinicians. This chapter reviews key issues related to the incidence, prevalence, and care of patients with diabetes in critical care settings.

Epidemiology and Burden of Illness

Diabetes is a prevalent metabolic disorder estimated to affect more than 340 million people worldwide. The United States alone had 29.1 million people living with diabetes in 2012, comprising 9.9% of the total population. This number still is expected to rise with one study claiming it may be possible that one in three adults living in the United States will be diagnosed with diabetes by 2050. This high prevalence and increasing incidence are important in that these patients are at high risk for AKI in a multitude of settings.

Patients with diabetes frequently require hospital admission for diabetic and nondiabetic complications. In general, it has been reported that patients with diabetes have a threefold greater chance of hospitalization for all causes compared with their nondiabetic counterparts. Despite focus on optimal diabetic management, there is ongoing evidence that complications including myocardial infarction, congestive heart failure, stroke, peripheral vascular disease, AKI, and infections will continue to increase. Diabetics with evidence of kidney disease (proteinuria, abnormal kidney function) are at greater risk of AKI than those without renal involvement. Retinopathy, neuropathy, coronary disease, and peripheral vascular disease are more prevalent in patients with nephropathy. Patients with diabetes may require intensive care, most commonly for treatment of conditions other than diabetes. Once hospitalized, patients with diabetes have a longer duration of stay than nondiabetics with an increased risk for complications and increased mortality. Therefore efficient and effective treatment for these patients is increasingly important from a patient outcome and a cost perspective.

Diabetic Kidney Disease: Kidneys at Risk

Diabetic nephropathy is common both in type 1 and type 2 DM. In type 1 diabetes, earlier literature reported a 16% chance of developing end-stage renal disease within 30 years after the initial diagnosis. Historically, patients with type 2 diabetes were believed to have a better renal prognosis, but recent epidemiologic studies have suggested that the renal risk of a patient with type 2 DM is similar to that of a patient with type 1 diabetes. Type 2 diabetes, which is 10 to 15 times more common than type 1, is the leading cause of end-stage renal disease in the Western world.