Page 73 Complete Your CE Test Online - Click Here PATHOPHYSIOLOGY Compared to anorexia nervosa, the pathophysiology of bulimia nervosa does not show the effects of near starvation. This does not mean, however, that the client is free from dangerous pathophysiological effects. These effects can include fluid and electrolyte imbalances[14] . Electrolyte imbalances Several electrolyte imbalances may be found in persons suffering from bulimia nervosa. Hypokalemia Hypokalemia may exist. Hypokalemia is defined as potassium levels lower than 3.5 mEq/L. The imbalance occurs when there is a significant loss of gastrointestinal fluids from prolonged vomiting or diarrhea[14] . Fluid loss from vomiting or diarrhea are characteristic of the purging behaviors associated with bulimia nervosa as is the abuse of diuretics, which also causes significant loss of fluids[9,14] . Other signs of hypokalemia include[9,14] : ● ● Weakness of the skeletal muscles, especially in the legs. ● ● Paresthesia (tingling or “pins and needles” sensations). ● ● Leg cramps. ● ● Decreased or absent deep tendon reflexes. ● ● Weakness of respiratory muscles that can lead to respiratory distress. ● ● Tachycardia. ● ● Rapid respiratory rate. ● ● Anorexia, nausea, and vomiting. Hypokalemia can also lead to cardiac problems. Signs of hypokalemia- related cardiac problems include[14] : ● ● Weak, irregular pulse. ● ● Arrhythmias. ● ● Orthostatic hypotension. ● ● Bradycardia or tachycardia. ● ● ECG changes, such as a flattened or inverted T wave, a depressed ST segment, and a characteristic U wave. Hyponatremia Decreased sodium, or hyponatremia, may develop. Hyponatremia is defined as a sodium level less than 135 mEq/L. When diuretics are abused, the body loses both fluid and sodium and imbalance occurs[14] . The signs and symptoms of hyponatremia can vary from client to client, depending on how quickly the client’s sodium level drops[14] . Some general signs and symptoms of this imbalance include[14] : ● ● Poor skin turgor. ● ● Dry, cracked skin. ● ● Weak, rapid pulse. ● ● Hypotension. ● ● Orthostatic hypotension. ● ● Central venous pressure (CVP), pulmonary artery pressure (PAP), and pulmonary wedge pressure (PAWP) may be decreased. Hypochloremia Hypochloremia, or a deficiency of chloride is defined as a serum chloride level below 98 mEq/L. Chlorine is lost when fluid is lost from the gastrointestinal (GI) tract or from the kidneys[14] . Clients with hypochloremia often exhibit signs and symptoms of various other electrolyte imbalances (i.e. hypokalemia and hyponatremia) or metabolic alkalosis. The nerves are more irritable and excitable, potentially resulting in tetany, hyperactive deep tendon reflexes, and hypertonicity of the muscles[14] . Additional signs and symptoms include[14] : ● ● Muscle cramps. ● ● Muscle twitching. ● ● Muscle weakness. ● ● Irritability. ● ● Agitation. If levels continue to dangerously decrease, the client may develop seizures, arrhythmias, respiratory arrest, and coma[14] . Metabolic alkalosis Elevated bicarbonate levels may lead to metabolic alkalosis[2] . This imbalance is caused by a decrease in hydrogen ion production characterized by a blood pH above 7.45 and a bicarbonate level above 26 mEqu/L[14] . A variety of problems can lead to metabolic alkalosis. The most common cause is an excessive loss of acid from the GI tract. For example, prolonged periods of vomiting can cause a loss of hydrochloric acid from the stomach. Diuretic use is another cause. Thiazide and loop diuretics cause fluid loss as well as the loss of hydrogen, potassium, and chloride ions from the kidneys. Low potassium levels cause the kidneys to excrete hydrogen ions as they try to conserve potassium. Potassium moves out of the cells, hydrogen moves into the cells, and the result is alkalosis[14] . Signs and symptoms of metabolic alkalosis include[14] : ● ● In the early stages of metabolic alkalosis, slow, shallow respirations prevail. As the problem continues, hypoxemia (low levels of oxygen in the blood) develops, which stimulates and increases respirations. ● ● Anorexia. ● ● Apathy. ● ● Confusion. ● ● Cyanosis. ● ● Hypotension. ● ● Loss of reflexes. ● ● Twitching of muscles. ● ● Weakness. ● ● Nausea and vomiting. Complications of bulimia nervosa There are a number of potential complications of bulimia nervosa. These include the following problems. ● ● Suicide risk: Persons affected by bulimia nervosa have an increased risk of suicide. Clients should be assessed for suicidal ideation as well as the co-existence of other mental health disorders such as depression, obsessive-compulsive disorder, and other anxiety disorders[1] . ● ● Dental erosion: The acidic gastric contents expelled by vomiting destroy tooth enamel. This can lead to severe tooth decay and dental problems[2,9,12] . ● ● Esophageal damage leading to esophageal bleeding: Such bleeding can progress to hemorrhage[2,9] . ● ● Gastric rupture: The pressure and damage to the gastric area from prolonged episodes of vomiting can lead to significant bleeding, hemorrhage, and peritoneal infection because of the release of gastric contents following rupture[2,9,12] . ● ● Cardiac problems: Cardiac problems can occur as a result of electrolyte imbalances. Many of these imbalances affect the cardiac system and can cause dangerous, even life-threatening arrhythmias[1,2,9,12] .