Question 1

A male patient with a history of heavy alcohol use has been admitted to hospital for malnutrition and suspected pancreatitis. The patient's diagnostic workup suggests alcoholic ketoacidosis as a component of his current health problems. He is somewhat familiar with the effect that drinking has had on his nutrition and pancreas but is wholly unfamiliar with the significance of acid-base balance. How best could his care provider explain the concept to him?

Accepted Answer

Metabolic activity is highly contingent on a narrow range of pH. Normal pH is slightly basic, not acidic, and appropriate pH is maintained by the lungs and kidneys, not vice versa. The action of the respiratory and renal systems, not particular food or fluid intake, has the most salient effect on the acid-base balance.

Question 2

When explaining how carbon dioxide combines with water to form carbonic acid as part of acid-base lecture, the faculty instructor emphasized that which enzyme is needed as a catalyst for this reaction?

Accepted Answer

^A^{lthough CO}2 ^{is a gas and not an acid, a small percentage of the gas combines with water to form H}2^CO3^{. The reaction that generates H}2^CO3 ^{from CO}2 ^{and water is}catalyzed by an enzyme called carbonic anhydrase.

Question 3

A 31-year-old client with a diagnosis of end-stage liver failure has been admitted to the intensive care unit of a hospital. Arterial blood sampling indicates that the man has an acid-base imbalance. Which of the following situations is most likely to result in an inappropriate pH?

Accepted Answer

Albumin and plasma globulins are key protein buffers in the vascular compartment; consequently, a low albumin level, as is common in liver failure, is apt to result in acid-base imbalances. Answer choices A, C, and D all convey normal physiological processes that help to maintain pH.

Question 4

A patient with ESRD comes into the emergency department in severe acidosis. The nurse notes that the respiratory rate is 36 breaths/minute. The nurse understands the pathophysiology of this response and explains to the student nurse that the patient's

Accepted Answer

The second line of defense against acid-base disturbances is the control of extracellular ^CO2 ^{by the lungs. Blood PCO}2 ^{and pH are important regulators of ventilation.}Chemoreceptors in the brain stem and the peripheral chemoreceptors in the carotid and ^{aortic bodies sense changes in PCO}2 ^{and pH and alter the ventilatory rate.}

Question 5

Place the following stages of the hydrogen ion elimination and bicarbonate conservation in the proximal tubules of the nephrons in the ascending chronological order. Use all the options.

Accepted Answer

Renal regulation of pH involves the secretion of hydrogen ions into the tubular fluid, the combining of hydrogen ions with bicarbonate yielding carbonic acid, followed by the decomposition of carbonic acid into carbon dioxide and water.

Question 6

Following several days in an acidotic state, a hospital patient has returned to desired pH. Which of the following processes could have contributed to the resolution of the patient's health problem?

Accepted Answer

The phosphate and ammonia buffer systems are secondary, but important, processes that contribute to the maintenance of appropriate pH. The kidneys must reabsorb nearly all the body's stores of HCO ^-3to maintain homeostasis, and they are not involved in CO control. Hydrogen-potassium exchange, not hydrogen-sodium exchange, is a component of acid-base control.

Question 7

When trying to explain the role of potassium and hydrogen related to acid-base balance, which of the following statements is accurate?

Accepted Answer

^{Hypokalemia is a potent stimulus for H}⁺^{secretion and HCO}3 ^{reabsorption. Acidosis}tends to increase H⁺elimination and decrease K⁺elimination, with a resultant increase in plasma potassium levels, whereas alkalosis tends to decrease H⁺elimination and increase K⁺elimination, with a resultant decrease in plasma K⁺levels.

Question 8

A client with poorly controlled diabetes mellitus presents to the emergency department with suspected ketoacidosis. Which of the following diagnostic results would most likely confirm this diagnosis?

Accepted Answer

^{Increased CO}2 ^{levels, an increased anion gap, and a base deficit are all associated with}an acidotic state. Base excess, low oxygen, high potassium, high ammonia, and decreased anion gap would not suggest acidosis.

Question 9

A patient who has just had her first postoperative dinner out to celebrate her recovery from an intestinal bypass is brought to the emergency room by her spouse. He reports that the patient seems disoriented and is slurring her words. The patient did not have any alcohol with her pasta dinner. Which of the following might be the cause of her symptoms?

Accepted Answer

A unique form of lactic acidosis, called D-lactic acidosis, can occur in persons with intestinal disorders that involve the generation and absorption of D-lactic acid. D-lactic acidosis can occur in persons with jejunoileal bypass, in which there is impaired reabsorption of carbohydrate in the small intestine. Persons with D-lactic acidosis experience episodic periods of metabolic acidosis often brought on by eating a meal high in carbohydrates. Manifestations include confusion, cerebellar ataxia, slurred speech, and loss of memory. They may complain of feeling (or may appear) intoxicated.

Question 10

The nurse is caring for a patient with ketoacidosis, who is complaining of increasing lethargy and occasional confusion following several weeks of rigid adherence to a carbohydrate-free diet. The nurse understands which of the following phenomena is most likely occurring?

Accepted Answer

Low-carbohydrate diets can induce the fat metabolism and consequent metabolic acidosis that is more commonly associated with diabetic ketoacidosis. The acidotic state is not classified as respiratory in nature and does not involve a buffer role for carbohydrates or insulin deficiency.

Question 11

A 14-year-old boy, appearing to be intoxicated, is brought to the emergency room by ambulance. The EMTs report that the boy has denied consuming anything out of the ordinary, but an open antifreeze container was found in the boy's room. Which of the following is likely to be used to treat the patient's symptoms?

Accepted Answer

Ethylene glycol is found in products ranging from antifreeze and deicing solutions to carpet and fabric cleaners. It tastes sweet and is intoxicating-the factors that contribute to its abuse potential. A lethal dose is approximately 100 mL. It is rapidly absorbed from the intestine, making treatment with either gastric lavage or syrup of ipecac ineffective. Fomepizole, with specific indications for ethylene glycol poisoning, was recently approved by the U.S. Food and Drug Administration.

Question 12

A patient who overdosed on aspirin is brought to the emergency department. The nurse caring for this patient should anticipate which of the following clinical manifestations? Select all that apply.

Accepted Answer

The salicylates cross the blood-brain barrier and directly stimulate the respiratory center, causing hyperventilation and respiratory alkalosis (answer choices A and C). The blood pressure is at normal range, and the urine output is normal or excessive depending on fluid intake. Bilateral crackles (fluid) in the lungs are usually a sign of heart failure.

Question 13

Which of the following individuals are at risk of developing metabolic alkalosis? Select all that apply.

Accepted Answer

Ingestion of bicarbonate, gastric suction, and vomiting are causes of metabolic alkalosis. Patients on mechanical ventilation are at risk of respiratory alkalosis, while heavy alcohol use and renal failure are associated with acidosis.

Question 14

A 55-year-old male client with a history of cardiovascular disease has been admitted to the intensive care unit after recovering from cardiogenic shock. In the hours since admission, the client's arterial blood gases indicate acidosis, most likely acute lactic acidosis. Which of the following signs, symptoms, and diagnostic findings might his care team anticipate before the acid-base balance is restored? Select all that apply.

Accepted Answer

As with any form of acidosis, pH is apt to be lower than normal. Metabolic acidosis is also associated with dysrhythmias, decreased alertness, and nausea and vomiting.Respiration is likely to be increased in both rate and depth.

Question 15

A nurse is providing care for a client who has been diagnosed with metabolic alkalosis after several days of antacid use. Which of the following treatments should the nurse prepare to give?

Accepted Answer

KCl administration facilitates the renal retention of hydrogen ions,resulting in lowering of pH. It is not possible to administer free H+ions, and sodium bicarbonate wouldexacerbate her condition. Mechanical ventilation is indicated in cases of respiratoryacidosis.

Question 16

A hospital patient's arterial blood gases indicate normal levels of oxygen and increasedcarbon dioxide. The patient's respiratory rate is 12 breaths/minute (normal 14 to 20breaths/minute) with all other vital signs within normal range. While not evident from assessment and diagnostics, the patient's kidneys are minimizing both H+ excretion and HCO3-reabsorption. What is this client'smost likelydiagnosis?

Accepted Answer

In response to increased bicarbonate, the client is hypoventilating to increase carbondioxide partial pressure. As well, renal compensation is aimed at lowering pH by bothr educing H+ excretion and HCO3-reabsorption.The given data are incongruent with the other major acid-base imbalances.

Question 17

A 77-year-old female diagnosed with chronic obstructive pulmonary disease (COPD) is^{experiencing impaired gas exchange and CO}2 ^{retention, despite a rapid respiratory rate.} Which of the following pathophysiological principles would her health care team expect if her compensatory mechanisms are working?

Accepted Answer

Respiratory acidosis is accompanied by renal adaptation with a more marked increase in plasma HCO ^-and a lesser decrease in pH. Her pH is likely below 7.35, and the likely renal response involves the reabsorption of HCO ^-and secretion of H⁺. Excess CO production is not a common manifestation of obstructive lung disease.

Question 18

The ICU nurse is concerned with her patient's arterial blood gas (ABG) results-^{especially the pH 7.30; and PCO}2 ^{49 mm Hg. The nurse interprets these ABG results to} mean respiratory acidosis. The nurse knows which of the following are clinical manifestations of respiratory acidosis? Select all that apply.

Accepted Answer

Carbon dioxide readily crosses the blood-brain barrier, exerting its effects by changing ^{the pH of brain fluids. Elevated levels of CO}2 ^{produce vasodilation of cerebral blood}vessels, causing headache, blurred vision, irritability, muscle twitching, and psychological disturbances. Distracters C and D are related to hypocalcaemia.Numbness in the fingers and toes correlates with respiratory alkalosis.

Question 19

A 55-year-old woman has presented to the emergency department following a panic attack. Her blood pressure, respiratory rate, and heart rate are all highly elevated, while her temperature and oxygen saturation are within normal ranges. What is the woman's body most likely doing to address the changes in pH associated with her situation?

Accepted Answer

Renal compensation for respiratory alkalosis involves decreased bicarbonate reabsorption. Manipulation of Cl^-ions is not a compensatory mechanism that the body ^{is capable of, and increased CO}2 ^{levels and decreased H}⁺^{would compensate for her}acid-base imbalance.

Question 20

In the neurotrauma unit, a teenager with a closed head injury related to an automobile accident is experiencing high intracranial pressure (ICP). He is intubated and is on a ventilator. One treatment for this is to allow him to progress into which acid-base imbalance in an attempt to lower ICP?

Accepted Answer

Respiratory alkalosis is seen as a treatment with the ventilator with intubated people experiencing high intracranial pressure (ICP) in order to attempt to lower the ICP.

Quiz 9: Inflammation, Tissue Repair, and Wound Healing