45 Diabetes mellitus
Overview/pathophysiology
Other types:
Formerly termed secondary diabetes, these include the following:
• Diseases of the exocrine pancreas: Pancreatitis, cystic fibrosis, hemochromatosis, trauma, infection, pancreatic cancer, and pancreatectomy may result in destruction of beta islet cells. All diseases except cancer generally involve extensive pancreatic destruction.
• Drug-induced by insulin antagonists: Many drugs impair insulin secretion, including phenytoin, steroids (hydrocortisone, dexamethasone), hormones (estrogen), intravenous (IV) pentamidine, nicotinic acid, thyroid hormone, thiazides, alpha-interferon, and rat poison.
• Endocrine dysfunction/hormonal diseases: Growth hormone, epinephrine, cortisol, and glucagons antagonize insulin and may be increased when diseases such as acromegaly, Cushing’s syndrome, pheochromocytoma, or glucagonoma are present. Presence of excess antagonistic hormones results in reduced insulin action, and with somatostatinoma and aldosteronoma, insulin secretion may be reduced.
• Genetic defects of the beta cell: An autosomal dominant pattern results in severely impaired insulin secretion, most often characterized by hyperglycemia beginning before 25 years of age; it is also termed maturity onset diabetes of the young.
• Genetic defects in insulin action: A genetic defect manifested as abnormal insulin action is reflected by hyperinsulinemia with mild to severe hyperglycemia. Women with acanthosis nigricans and those with polycystic ovaries may have this type of insulin resistance. Leprechaunism and Rabson-Mendenhall syndrome are two pediatric syndromes in this category.
• Infections: Presence of several different viruses, including rubella, coxsackievirus B, cytomegalovirus (CMV), adenovirus, and mumps has resulted in beta cell destruction.
• Uncommon immune-mediated diabetes: Antiinsulin receptor antibodies bind to insulin receptors and can either block or increase binding of insulin, resulting in either hyperglycemia or hypoglycemia. Systemic lupus erythematosus and “stiff-man” syndrome are examples of implicated disorders.
• Other genetic syndromes: Hyperglycemia has been linked to patients with Down’s syndrome, Klinefelter’s syndrome, Turner’s syndrome, and Wolfram’s syndrome.
Complications
Problems with insulin:
Systemic allergic reactions:
With the advent of primarily human insulin and insulin analogues, systemic allergic reactions are extremely rare. The episode begins with a localized skin reaction, which evolves into generalized urticaria or anaphylaxis. Patients must be desensitized to insulin by progression from minuscule to more normal doses over the course of 1 day, using a series of subcutaneous injections.
Diagnostic tests
Once the diagnosis of diabetes mellitus is made
12-lead electrocardiogram (ECG):
Nursing diagnosis:
Risk for unstable blood glucose level
related to inadequate blood glucose monitoring, dietary intake, and/or medication management
| ASSESSMENT/INTERVENTIONS | RATIONALES |
|---|---|
| Assess blood glucose before meals and at bedtime. | This monitors effectiveness of blood glucose control at times when patient’s glucose is not increased by food being digested. The American Diabetes Association and American Association of Clinical Endocrinologists (2009) have determined that both morbidity and mortality could be reduced for thousands of patients if hyperglycemia is diagnosed at admission and treated throughout hospitalization. Guidelines state that in critically ill patients, blood sugar level should be maintained at 140-180 mg/dL. Non–intensive care patients should be maintained at a premeal level of no more than 140 mg/dL and a maximum level of 180 mg/dL. Previously accepted tight glycemic control guidelines were changed following the NICE Sugar Trial, published in 2009. The trial revealed benefits of tight control did not outweigh any potential negative outcomes of low blood sugar. |
| Assess for changes in mentation, apprehension, erratic behavior, trembling, slurred speech, staggering gait, and seizure activity. Treat hypoglycemia as prescribed. | These are signs of hypoglycemia. Patients with hypoglycemia may experience vasodilation and diminished myocardial contractility, which decrease cerebral circulation and impair cognition. |
| In addition to sensation, assess capillary refill, temperature, peripheral pulses, and color. | This assessment monitors patient’s peripheral perfusion to detect macroangiopathy or PVD. |
| Administer basal, prandial, and correction doses of insulin as prescribed. | Adherence to the therapeutic regimen is essential for promoting optimal tissue perfusion. Progression of vascular disease and neuropathy, including blindness, kidney failure, gastroparesis, heart attack, and stroke is the root cause of all complications of DM. By keeping serum glucose in a more normal range, the vascular endothelium receives better nourishment within the cells and will be less likely to deteriorate. |
| Encourage and teach patient how to perform regular home blood glucose monitoring. | Blood glucose is generally monitored before meals, at bedtime, and possibly during the night (3:00 AM) in order to assess whether a correction dose of short-acting insulin is needed. Self-monitoring by patients is extremely useful in reducing complications. |
| Check BP q4h. Alert health care provider to values outside patient’s normal range. Administer antihypertensive agents as prescribed and document response. | Hypertension is commonly associated with diabetes. Careful control of BP is critical in preventing or limiting development of heart disease, stroke, retinopathy, and nephropathy. |
| Monitor for orthostatic hypotension after administering blood pressure medications. | Orthostatic hypotension is a potential side effect of antihypertensive agents and of autonomic neuropathy in which the patient’s compensatory mechanisms may be impaired. |
| Protect patients with impaired peripheral perfusion from injury caused by sharp objects or heat (e.g., avoid use of heating pads; always wear shoes outdoors and slippers at home). | Patients may experience decreased sensation in the extremities because of peripheral neuropathy. |
| Teach patient to avoid pressure at back of the knees by not crossing legs or “gatching” bed under the knees. Caution patient to avoid garments that constrict circulation to the extremities and lower body. For additional information, see Risk for Impaired Skin Integrity p. 353. | These actions could cause venous stasis and reduction in arterial perfusion in patients with macroangiopathy or impending PVD. |
| As indicated, orient patient to locations of such items as water, tissues, glasses, and call light. | This orientation provides necessary information and a safe environment for patients with diminished eyesight caused by diabetic retinopathy. |
| Monitor laboratory values for changes in renal function. | Laboratory values that would signal changes in renal function include increases in blood urea nitrogen (more than 20 mg/dL) and creatinine (more than 1.5 mg/dL). Approximately half of all persons with type 1 DM develop chronic kidney disease (CKD) and end-stage renal disease. Proteinuria (protein more than 8 mg/dL in a random sample of urine) or microalbuminuria are early indicators of developing CKD. (See “Chronic Kidney Disease,” p. 202, for more information.) |
| Also monitor urine output, especially after exposure to contrast medium. Observe these patients for indicators of acute renal failure (ARF). (See “Acute Renal Failure,” p. 187, for more information.) | Individuals with DM and with reduced renal function are at significant risk for dehydration and development of ARF after exposure to contrast medium. Patients who will receive contrast medium should be well hydrated and possibly receive several doses of oral acetylcysteine or an IV bicarbonate infusion to protect the kidneys from contrast-related deterioration. |
| In Addition Assess for the Following: | |
| Individuals with DM may experience multiple problems resulting from autonomic neuropathy. | |
| Orthostatic hypotension: – Check BP while patient is lying down, sitting, and then standing. Alert health care provider to significant findings. < div class='tao-gold-member'>
Only gold members can continue reading. Log In or Register to continue
 Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
Get Clinical Tree app for offline access
| |