Symptoms of severe hyperglycemia include polyuria, polydipsia, and weight loss. As the patient's blood glucose increases, neurologic symptoms can develop. The patient may experience lethargy, focal neurologic deficits, or altered mental status. The patient can progress to a comatose state. 

Patients with diabetic ketoacidosis may present with nausea, vomiting and abdominal pain in addition to the above symptoms. They also may have a fruity odor to their breath and have rapid shallow respirations, reflecting compensatory hyperventilation for the acidosis. 

The physical examination can reveal signs of hypovolemia like hypotension, tachycardia, and dry mucous membranes. 

When evaluating a patient for hyperglycemia, the focus should be on the patient's cardiorespiratory status, mental status, and volume status. Bedside serum glucose can be obtained quickly. Testing includes serum electrolytes with the calculation of the anion gap, BUN and creatinine, and complete blood count. Urinalysis by dipstick assesses for glucose and ketones in the urine. Arterial blood gas or venous blood gas may be necessary if serum bicarbonate is substantially reduced.[9]

Blood Glucose Determination

To determine if the patient has developed type 2 diabetes the patient needs to have the following outcomes on these tests:

• A fasting plasma glucose level of 126 mg/dL or higher.

• A 2-hour plasma glucose level of 200 mg/dL or higher during a 75-g oral glucose tolerance test (OGTT).

• Random plasma glucose of 200 mg/dL or higher in the presence of symptoms of hyperglycemia.

• A hemoglobin A1c level of 6.5% or higher.

The treatment goals of hyperglycemia involve eliminating the symptoms related to hyperglycemia and reducing long-term complications. Glycemic control in patients with type 1 diabetes is achieved by a variable insulin regimen along with proper nutrition. Patients with type 2 diabetes are managed with diet and lifestyle changes as well as medications. Type 2 diabetes also may be managed on oral glucose-lowering agents. Patients with hyperglycemia need to be screened for complications including retinopathy, nephropathy, and cardiovascular disease. 

Goals of Treatment

Treatment goals are to reduce the following complications associated with hyperglycemia:

• Kidney and eye disease by regulation of blood pressure and lowering hyperglycemia.
• Ischemic heart disease, stroke and peripheral vascular disease by control of hypertension, hyperlipidemia, and cessation of smoking.
• Reduce the risk of metabolic syndrome and stroke by control of body weight and control of hyperglycemia.

Patients who have hyperglycemia and are confirmed to have type 2 diabetes need to be referred to an endocrinologist. Unless there is a contraindication, the drug of choice to lower hyperglycemia is metformin. In addition, some patients may require insulin therapy in combination with other agents.

Prevention of complications

To prevent complications of hyperglycemia, the following preventive approaches are recommended:

• Refer to an ophthalmologist for yearly eye exams.
• Monitor A1c levels every 3-6 months.
• Check urinary albumin levels every 12 months.
• Examine the feet at each clinic visit.
• Maintain the Blood pressure to less than 130/80 mmHg.
• Initiate statin therapy if the patient has hyperlipidemia.

Some patients are prone to greater glycemic variability of their blood sugars within a day and also variability for the same time on different days, thereby causing frequent episodes of hypoglycemia and hyperglycemia. These patients need close monitoring by an endocrinologist with a treatment plan intended to reduce both the risks or at least maintain one risk while reducing the other.

Differential diagnosis of hyperglycemia include

1. Diabetes mellitus type 1 and 2.

2. Stress-induced hyperglycemia.

3. Medications induced like steroids.

4. Acromegaly

5. Cushing's disease.

6. Iatrogenic (from intravenous fluids with dextrose and tube feeds).

The prognosis of individuals with hyperglycemia depends on how well the levels of blood glucose are controlled. Chronic hyperglycemia can cause severe life- and limb-threatening complications. Changes in lifestyle, regular physical exercise, and changes in diet are the keys to a better prognosis. Individuals who maintain euglycemia have a markedly better prognosis and an improved quality of life compared to individuals who remain hyperglycemic. Once the complications of hyperglycemia have developed, they are basically irreversible. Countless studies have shown that untreated hyperglycemia shortens lifespan and worsens the quality of life. Thus, an aggressive lowering of hyperglycemia must be initiated, and patients must be closely followed. Studies suggest that one should try to achieve an A1C level of less than 7%. However, controlling blood sugars too tightly can result in hypoglycemia which is not well tolerated by elderly individuals who already may have a pre-existing cardiovascular disease.[10]

Complications of untreated or uncontrolled hyperglycemia over a prolonged period of time include:

1. Microvascular complications

• Retinopathy
• Nephropathy
• Neuropathy

2. Macrovascular complications

• Coronary artery disease
• Cerebrovascular disease
• Peripheral vascular disease

Hyperglycemia is common postoperatively. High blood sugars postoperatively are associated with higher perioperative complications so the target blood sugars should be kept around 140-180 mg/dL. Multiple teams take care of postoperative patients during their hospital stay, thereby needing a multidisciplinary team to create and follow protocols to treat hyperglycemia and decrease perioperative complications.[11]

Hyperglycemia can be managed by internists but if remains uncontrolled then consultation with endocrinology is needed. 

Patients with diabetes are more prone to depression than those without diabetes. This is more so in newly diagnosed diabetics and young patients due to significant lifestyle changes that are needed.[12]

Patients diagnosed with diabetes need comprehensive care in the first few months of the diagnosis as management can be overwhelming and time-consuming. Patients and family members need to be educated about testing blood sugar, taking medications especially insulin, going to their medical appointments, and lifestyle modifications which include diet and exercise. Patients need to be given information for diabetes classes. 

Patients with severe hyperglycemia should be assessed for clinical stability including mentation and hydration. Diabetic ketoacidosis and hyperglycemic hyperosmolar state are acute, severe disorders related to hyperglycemia. 

Patients confirmed with type 2 diabetes are faced with a life-long challenge to maintain euglycemia. This is not an easy undertaking and is also prohibitively expensive. Patients must be educated that making changes in their lifestyle can markedly improve their prognosis.

Diabetes management is very complex and time-consuming. A newly diagnosed patient can easily become overwhelmed, leading to non-compliance with treatment which would further lead to irreversible complications. Patients and family members need to work closely with primary care physicians, endocrinologists, dieticians, and diabetic educators to help achieve optimal therapeutic goals and prevent complications. Home health nursing services for disease management in the first few weeks has been shown to improve outcomes and should be utilized when available.[13]