Category: Critical Care Nursing Macrocytic anemias most commonly result from deficiencies of vitamin B12 or folate. Serum levels of both micronutrients are significantly affected by dietary modifications. Methylmalonic acid and homocysteine levels need to be obtained.
Category: Critical Care Nursing The complete blood count is the initial laboratory test performed in the evaluation of anemia. Based on the MCV, the anemia can be classified into microcytic (MCV less than 80 fL), normocytic (MCV 80-100 fL) and macrocytic (MCV more than 100 fL).
Category: Critical Care Nursing In the absence of bleeding, hemodilution is mostly responsible for the decrease in hemoglobin levels in the first 72 hours after admission to the ICU and results from the liberal use of crystalloids and colloids in the resuscitation of critically ill patients.
Category: Critical Care Nursing When blood glucose concentration indicates hypoglycemia, it should be corrected immediately and the cause should be investigated. If there is no obvious medication-related cause, insulin and C peptide levels can be helpful.
Category: Critical Care Nursing Various rate and rhythm disturbances, including sinus tachycardia, sinus bradycardia, atrial and ventricular ectopies and ventricular repolarization abnormalities, have been observed during acute hypoglycemic episodes.
Category: Critical Care Nursing During episodes of hypoxia or ischemia, myocardial cells preferentially use glucose as a substrate for adenosine triphosphate (ATP) generation. Hypoglycemic episodes stimulate the sympathoadrenal system, which can be proarrythmogenic.
Category: Critical Care Nursing Hypoglycemic coma may occur when glucose levels are below 40-50 mg/dL. The neurons most sensitive to hypoglycemia are located in the superficial layers of the cortex, the hippocampus, the caudate nucleus and the subiculum.
Category: Critical Care Nursing Patients experiencing hypoglycemia present with either adrenergic (tremors, palpitations, anxiety), cholinergic (sweating, paresthesias) or neuroglycopenic symptoms (cognitive, behavioral, psychomotor changes, seizures, coma).
Category: Critical Care Nursing The brain uses glucose and ketone bodies as fuel, especially during starvation. Brain glucose concentrations drop close to zero when blood glucose concentration falls below 36 mg/dL (2 mmol/L).
Category: Critical Care Nursing The brain and heart are two organs that are dependent on glucose for energy utilization and function. Consequently, most of the symptoms of hypoglycemia are related to these two organ systems.
Category: Critical Care Nursing Based on the NICE-SUGAR trial, most centers target a blood glucose level of less than 180 mg/dL (10 mmol/L) for critically ill patients in an attempt to treat hyperglycemia while reducing the incidence of hypoglycemia.
Category: Critical Care Nursing An increase in the levels of catecholamines, growth hormone, glucocorticoids, and glucagon, along with an increase in cytokines and peripheral insulin resistance, may play an important role in the genesis of stress-induced hyperglycemia.
Category: Critical Care Nursing For patients with hypercalcemia and underlying malignancy, treatment with salmon calcitonin, pamidronate or plicamycin may be necessary. These agents act to inhibit bone resorption. Hydrocortisone can also be used.
Category: Critical Care Nursing The treatment of hypercalcemia should be directed at the underlying medical condition. Saline infusion and diuresis are indicated in symptomatic patients and when the serum calcium level rises above 14 mg/dL (3.5 mmol/L).
Category: Critical Care Nursing Mild hypercalcemia is usually asymptomatic. However, patients with circulating calcium above 12 mg/dL may experience confusion, psychosis and coma. Patients also may experience nausea, vomiting, constipation, abdominal pain and ileus.
