Acid-Base Imbalance

4. The nurse is making a home visit to a child who has a chronic disease. Which finding has the greatest implication for acid-base aspects of this patients care? a. Urine output is very small today. b. Whites of the eyes appear more yellow. c. Skin around the mouth is very chapped. d. Skin is sweaty under three blankets.

ANS: A Oliguria decreases the excretion of metabolic acids and is a risk factor for metabolic acidosis. Jaundice requires follow-up but is not an acid-base problem. Perioral chapped skin needs intervention but is not an acid-base issue. With three blankets, diaphoresis is not unusual.

1. The patient had diarrhea for 5 days and developed an acid-base imbalance. Which statement would indicate that the nurses teaching about the acid-base imbalance has been effective? a. To prevent another problem, I should eat less sodium during diarrhea. b. My blood became too acid because I lost some base in the diarrhea fluid. c. Diarrhea removes fluid from the body, so I should drink more ice water. d. I should try to slow my breathing so my acids and bases will be balanced.

ANS: B Diarrhea causes metabolic acidosis through loss of bicarbonate, which is a base. Eating less sodium during diarrhea increases the risk of ECV deficit. Although diarrhea does remove fluid from the body, it also removes sodium and bicarbonate which need to be replaced. Rapid deep respirations are the compensatory mechanism for metabolic acidosis and should be encouraged rather than stopped.

3. The patient has severe hyperthyroidism and will have surgery tomorrow. What assessment is most important for the nurse to assess in order to detect development of the acid-base imbalance for which the patient has highest risk? a. Urine output and color b. Level of consciousness c. Heart rate and blood pressure d. Lung sounds in lung bases

ANS: B Thyroid hormone increases metabolic rate, causing a patient with severe hyperthyroidism to have high risk of metabolic acidosis from increased production of metabolic acids. Metabolic acidosis decreases level of consciousness. Changes in urine output, urine color, and lung sounds are not signs of metabolic acidosis. Although metabolic acidosis often causes tachycardia, many other factors influence heart rate and blood pressure, including thyroid hormone.

2. Which statements said by patients indicate that the nurses teaching regarding prevention of acid-base imbalances is successful? (Select all that apply.) a. Baking soda is an effective inexpensive antacid. b. I shall take my insulin on time every day. c. My aspirin is on a high shelf away from children. d. I have reliable transportation to dialysis sessions. e. Fasting is a great way to lose weight rapidly.

ANS: B, C, D Taking insulin as prescribed helps prevent diabetic ketoacidosis. Safeguarding aspirin from children prevents metabolic acidosis from increased acid intake. Regular dialysis reduces the risk of metabolic acidosis from decreased renal excretion of metabolic acid. Baking soda is sodium bicarbonate and should not be used as an antacid due to the risk of metabolic alkalosis. Fasting without carbohydrate intake is a risk factor for starvation ketoacidosis.

1. The patient is hyperventilating from anxiety and abdominal pain. Which assessment findings should the nurse attribute to respiratory alkalosis? (Select all that apply.) a. Skin pale and cold b. Tingling of fingertips c. Heart rate of 102 d. Numbness around mouth e. Cramping in feet

ANS: B, D, E Hyperventilation is a risk factor for respiratory alkalosis. Respiratory alkalosis can cause perioral and digital paresthesias and pedal spasms. Pallor, cold skin, and tachycardia are characteristic of activation of the sympathetic nervous system, not respiratory alkalosis.

2. The patient has type B chronic obstructive pulmonary disease (COPD) exacerbated by an acute upper respiratory infection. Which blood gas values should the nurse expect to see? a. pH high, PaCO2 high, HCO3 high b. pH low, PaCO2 low, HCO3 low c. pH low, PaCO2 high, HCO3 high d. pH low, PaCO2 high, HCO3 normal

ANS: C Type B COPD is a chronic disease that causes impaired excretion of carbonic acid, thus causing respiratory acidosis, with PaCO2 high and pH low. This chronic disease exists long enough for some renal compensation to occur, manifested by high HCO3-. Answers that include low or normal bicarbonate are not correct, because the renal compensation for respiratory acidosis involves excretion of more hydrogen ions than usual, with retention of bicarbonate in the blood. High pH occurs with alkalosis, not acidosis.

5. The nurse has telephone messages from four patients who requested information and assistance. Which one should the nurse refer to a social worker or community agency first? a. Is there a place that I can dispose of my unused morphine pills? b. I want to lose at least 20 pounds without getting sick this time. c. I think I have asthma because I cough when dogs are near. d. I ran out of money and am cutting my insulin dose in half.

ANS: D Decreasing an insulin dose by half creates high risk of diabetic ketoacidosis, and this patient has the highest priority. The other patients have less priority due to lower risk situations with longer time course before development of an acid-base imbalance. The coughing when dogs are near is not a sign of a severe asthma episode that causes respiratory acidosis, although this patient does need attention after the insulin situation is handled. Disposing of morphine properly helps prevent respiratory acidosis from opioid overdose. Guidance regarding weight loss helps prevent starvation ketoacidosis.