Metabolic alkalosis
Metabolic alkalosis is a pH imbalance that occurs when the body accumulates too much of an alkaline substance, such as bicarbonate, and does not have enough acid to effectively neutralize the effects of the alkali. This disturbanceof the body's acid/base balance, can be a mild condition, brought on by vomiting, the use of steroids or diuretic drugs, or the overuse of antacids or laxatives. Metabolic alkalosis can also indicate a more serious problem with amajor organ such as the kidneys.
Metabolic alkalosis results from the body having more base than acid in the system. Chemists use the term "pH" to decribe how acidic or alkaline (also called basic) a substance is. Based on a scale of 14, a pH of 7.0 is neutral. ApH below 7.0 is an acid; the lower the number, the stronger the acid. A pH above 7.0 is alkaline; the higher the number, the stronger the alkali. Blood pHis slightly alkaline, with a normal range of 7.36-7.44.
Conditions that lead to a reduced amount of fluid in the body, like vomitingor excessive urination due to use of diuretic drugs, change the balance of fluids and salts. The blood levels of potassium and sodium can decrease dramatically, causing symptoms of metabolic alkalosis. Slowed breathing may be an initial symptom. The patient may also have episodes of apnea (not breathing) that may go on 15 seconds or longer. Cyanosis, a bluish or purplish discoloration of the skin, may also develop as a sign of inadequate oxygen intake. Nausea, vomiting, and diarrhea may also occur. Other symptoms can include irritability, twitching, confusion, and picking at bedclothes. Rapid heart rate, irregular heart beats, and a drop in blood pressure are also symptoms. Severe cases can lead to convulsions and coma.
Although metabolic alkalosis may be suspected based on symptoms, they are often not noticeable. The condition is usually confirmed by laboratory tests onblood and urine samples. Blood pH above 7.45 confirms the condition. Levels of other blood components, including salts like potassium, sodium, and chloride, fall below normal ranges. The level of bicarbonate in the blood will be high, usually greater than 29 mEq/L. Urine pH may rise to about 7.0 in metabolic alkalosis.
Treatment focuses first on correcting the imbalance. An intravenous line maybe started to administer fluids (generally normal saline, a salt water solution) and allow for the quick injection of other drugs that may be needed. Potassium chloride will be administered. Drugs to regulate blood pressure or heart rate, or to control nausea and vomiting might be given. Vital signs like pulse, respiration, blood pressure, and body temperature will be monitored. Theunderlying cause of the metabolic alkalosis must also be diagnosed and corrected.
If metabolic alkalosis is recognized and treated promptly, the patient may have no long-term complications; however, the underlying condition that causedthe alkalosis needs to be corrected or managed. Severe metabolic alkalosis that is left untreated will lead to convulsions, heart failure, and coma.
Patients receiving tube feedings or intravenous feedings must be monitored toprevent an imbalance of fluids and salts, particularly potassium, sodium, and chloride. Overuse of some drugs, including diuretics, laxatives, and antacids, should be avoided.