Nursing Concepts Acid-Base Balance Part 2

A nurse is teaching a client with gastritis about the need to avoid the intake of caffeinated beverages. The client asks why this is so important. Which explanation from the nurse would be most accurate?

"Caffeine stimulates the central nervous system and thus gastric activity and secretions, which need to be minimized to promote recovery." Explanation: Caffeine is a central nervous system stimulant that increases gastric activity and pepsin secretion. Caffeine is a diuretic that causes decreased fluid volume and potential dehydration. It does not lead to hemorrhage and does not interfere with absorption of vitamin B12.

Trousseau's sign is elicited by which of the following?

Carpopedal spasm is induced by occluding the blood flow to the arm for 3 minutes with the use of a blood pressure cuff. Explanation: A positive Trousseau's sign is suggestive of latent tetany. A positive Chvostek's sign is demonstrated when a sharp tapping over the facial nerve just in front of the parotid gland and anterior to the ear causes spasm or twitching of the mouth, nose, and eye. A positive Allen's test is demonstrated by the palm remaining blanched with the radial artery occluded. The radial artery should not be used for an arterial puncture. A positive Homans' sign is demonstrated when the patient complains of pain in the calf when his foot is dorsiflexed.

A nurse correctly identifies a urine specimen with a pH of 4.3 as being which type of solution?

Acidic Explanation: Normal urine pH is 4.5 to 8.0; a value of 4.3 reveals acidic urine pH. A pH above 7.0 is considered an alkaline or basic solution. A pH of 7.0 is considered neutral.

Which of the following clients is at highest risk for peptic ulcer disease?

Client with blood type O Explanation: Clients with blood type O are more susceptible to peptic ulcers than those with blood types A, B, and AB.

Which assessment findings would the nurse expect to find in the postoperative client experiencing fat embolism syndrome?

Column B Explanation: Fat embolism syndrome is characterized by fever, tachycardia, tachypnea, and hypoxia. Arterial blood gas findings include a partial pressure of oxygen (PaO2) less than 60 mm Hg, with early respiratory alkalosis and later respiratory acidosis.

The nurse is reporting on the results of client blood work to the oncoming nurse. Upon reviewing the data, it is noted that the client has an elevated uric acid level. Which inflammatory process would the nurse screen for on shift rounds?

Gout Explanation: Gout is a medical condition with symptoms of acute inflammatory arthritis that is caused by high levels of uric acid in the blood. The client has uric acid crystal deposits in the joint. The nurse would assess joint areas for pain, redness, and swelling. Rheumatoid arthritis is a chronic disease of joint inflammation and pain. Lupus erythematous is a chronic tissue disorder of the connective tissue and is known to have an elevated antinuclear antibody level. Osteoporosis has a deficiency in the serum calcium level.

Examination of a client's bladder stones reveal that they are primarily composed of uric acid. The nurse would expect to provide the client with which type of diet?

Low purine Explanation: A low-purine diet is used for uric acid stones; the benefits, however, are unknown. Clients with a history of calcium oxalate stone formation need a diet that is adequate in calcium and low in oxalate. Only clients who have type II absorptive hypercalciuria—approximately half of the clients—need to limit calcium intake. Usually, clients are told to increase their fluid intake significantly, consume a moderate protein intake, and limit sodium. Avoiding excessive protein intake is associated with lower urinary oxalate and lower uric acid levels. Reducing sodium intake can lower urinary calcium levels.

Which of the following arterial blood gas results would be consistent with metabolic alkalosis?

Serum bicarbonate of 28 mEq/L Explanation: Evaluation of arterial blood gases reveals a pH greater than 7.45 and a serum bicarbonate concentration greater than 26 mEq/L.

A nurse is providing client teaching about the body's plasma pH and the client asks the nurse what is the major chemical regulator of plasma pH. What is the best response by the nurse?

bicarbonate-carbonic acid buffer system Explanation: The major chemical regulator of plasma pH is the bicarbonate-carbonic acid buffer system. The renin-angiotensin-aldosterone system regulates blood pressure. The sodium-potassium pump regulate homeostasis. The ADH-ANP buffer system regulates water balance in the body.

The nurse observes a client's uric acid level of 9.3 mg/dL. When teaching the client about ways to decrease the uric acid level, which diet would the nurse suggest?

A low-purine diet Explanation: The nurse would suggest a low-purine diet. Foods to avoid are anchovies, animal organs and sardines. The other options do not lower the uric acids levels.

Which condition might occur with respiratory acidosis?

Increased intracranial pressure Explanation: If respiratory acidosis is severe, intracranial pressure may increase, resulting in papilledema and dilated conjunctival blood vessels. Increased blood pressure, increased pulse, and decreased mental alertness occur with respiratory acidosis.

As status asthmaticus worsens, the nurse would expect which acid-base imbalance?

Respiratory Acidosis Explanation: As status asthmaticus worsens, the PaCO2 increases and the pH decreases, reflecting respiratory acidosis.

A patient is being treated for status asthmaticus. What danger sign does the nurse observe that can indicate impending respiratory failure?

Respiratory acidosis Explanation: In status asthmaticus, increasing PaCO2 (to normal levels or levels indicating respiratory acidosis) is a danger sign signifying impending respiratory failure. Understanding the sequence of the pathophysiologic processes in status asthmaticus is important for understanding assessment findings. Respiratory alkalosis occurs initially because the patient hyperventilates and PaCO2 decreases. As the condition continues, air becomes trapped in the narrowed airways and carbon dioxide is retained, leading to respiratory acidosis.

The nurse is studying for a physiology test over the respiratory system. What should the nurse know about central chemoreceptors in the medulla?

They respond to changes in CO2 levels and hydrogen ion concentrations (pH) in the cerebrospinal fluid. Explanation: Central chemoreceptors in the medulla respond to changes in CO2 levels and hydrogen ion concentrations (pH) in the cerebrospinal fluid. Central chemoreceptors do not respond to changes in the O2 levels in the brain, changes in CO2 levels in the brain, changes in O2 levels, and bicarbonate levels in the cerebrospinal fluid.

Upon shift report, the nurse states the following laboratory values: pH, 7.44; PCO2, 30mmHg; and HCO3,21 mEq/L for a client with noted acid-base disturbances. Which acid-base imbalance do both nurses agree is the client's current state?

Compensated respiratory alkalosis Explanation: The question states that the client has a history of acid-base disturbance. The nurse would first note that the pH has returned to close to normal indicating compensation. The nurse then assess the PCO2 (normal: 35 to 45 mm Hg) and HCO3 (normal: 22 to 27mEq/L) levels. In a respiratory condition, the pH and the PCO2 move in opposite direction; thus, the pH rises and the PCO2 drops (alkalosis) or vice versa (acidosis). In a metabolic condition, the pH and the bicarbonate move in the same direction; if the pH is low, the bicarbonate level will be low, also. In this client, the pH is at the high end of normal, indicating compensation and alkalosis. The PCO2 is low, indicating a respiratory condition (opposite direction of the pH).

Examination of a client's bladder stones reveals that they are primarily composed of uric acid. The nurse would expect to provide the client with which type of diet?

Low purine Explanation: A low-purine diet is used for uric acid stones, although the benefits are unknown. Clients with a history of calcium oxalate stone formation need a diet that is adequate in calcium and low in oxalate. Only clients who have type II absorptive hypercalciuria—approximately half of the clients—need to limit calcium intake. Usually, clients are told to increase their fluid intake significantly, consume a moderate protein intake, and limit sodium. Avoiding excessive protein intake is associated with lower urinary oxalate and lower uric acid levels. Reducing sodium intake can lower urinary calcium levels.

A patient who has been treated for uric acid stones is being discharged from the hospital. What type of diet does the nurse discuss with the patient?

Low-purine diet Explanation: For uric acid stones, the patient is placed on a low-purine diet to reduce the excretion of uric acid in the urine. Foods high in purine (shellfish, anchovies, asparagus, mushrooms, and organ meats) are avoided, and other proteins may be limited.

A client in the emergency department reports that he has been vomiting excessively for the past 2 days. His arterial blood gas analysis shows a pH of 7.50, partial pressure of arterial carbon dioxide (PaCO2) of 43 mm Hg, partial pressure of arterial oxygen (PaO2) of 75 mm Hg, and bicarbonate (HCO3-) of 42 mEq/L. Based on these findings, the nurse documents that the client is experiencing which type of acid-base imbalance?

Metabolic alkalosis Explanation: A pH over 7.45 with a HCO3- level over 26 mEq/L indicates metabolic alkalosis. Metabolic alkalosis is always secondary to an underlying cause and is marked by decreased amounts of acid or increased amounts of base HCO3-. The client isn't experiencing respiratory alkalosis because the PaCO2 is normal. The client isn't experiencing respiratory or metabolic acidosis because the pH is greater than 7.35.

Which medication classification represents a proton (gastric acid) pump inhibitor?

Omeprazole Explanation: Omeprazole decreases gastric acid by slowing the hydrogen-potassium adenosine triphosphatase pump on the surface of the parietal cells. Sucralfate is a cytoprotective drug. Famotidine is a histamine-2 receptor antagonist. Metronidazole is an antibiotic, specifically an amebicide.

Which of the following as an example of a proton-pump inhibitor?

Omeprazole Explanation: Proton-pump inhibitors include omeprazole (Prilosec) and lansoprazole (Prevacid). Ranitidine (Zantac) is a histamine-2 antagonist; sucralfate (Carafate) is a cytoprotective agent; cisapride (Propulsid) is a gastrointestinal motility agent.

The nurse is administering an insulin drip to a patient in ketoacidosis. What insulin does the nurse know is the only one that can be used intravenously?

Regular Explanation: Short-acting insulins are called regular insulin (marked R on the bottle). Regular insulin is a clear solution and is usually administered 20 to 30 minutes before a meal, either alone or in combination with a longer-acting insulin. Regular insulin is the only insulin approved for IV use

A client is admitted to the unit with diabetic ketoacidosis (DKA). Which insulin would the nurse expect to administer intravenously?v

Regular Explanation: Regular insulin is administered intravenously to treat DKA. It is added to an IV solution and infused continuously. Glargine, NPH, and Lente are only administered subcutaneously.

In chronic obstructive pulmonary disease (COPD), decreased carbon dioxide elimination results in increased carbon dioxide tension in arterial blood, leading to which of the following acid-base imbalances?

Respiratory acidosis Explanation: Increased carbon dioxide tension in arterial blood leads to respiratory acidosis and chronic respiratory failure. In acute illness, worsening hypercapnia can lead to acute respiratory failure. The other acid-base imbalances would not correlate with COPD.

After being sick for 3 days, a client with a history of diabetes mellitus is admitted to the hospital with diabetic ketoacidosis (DKA). The nurse should evaluate which diagnostic test results to prevent dysrhythmias?

Serum potassium level Explanation: The nurse should monitor the client's potassium level because during periods of acidosis, potassium leaves the cell, causing hyperkalemia. As blood glucose levels normalize with treatment, potassium reenters the cell, causing hypokalemia if levels aren't monitored closely. Hypokalemia places the client at risk for cardiac arrhythmias such as ventricular tachycardia. DKA has a lesser affect on serum calcium, sodium, and chloride levels. Changes in these levels don't typically cause cardiac arrhythmias.

A client with a history of type 1 diabetes is demonstrating fast, deep, labored breathing and has fruity odored breath. What could be the cause of the client's current serious condition?

ketoacidosis Explanation: Kussmaul respirations (fast, deep, labored breathing) are common in ketoacidosis. Acetone, which is volatile, can be detected on the breath by its characteristic fruity odor. If treatment is not initiated, the outcome of ketoacidosis is circulatory collapse, renal shutdown, and death. Ketoacidosis is more common in people with diabetes who no longer produce insulin, such as those with type 1 diabetes. People with type 2 diabetes are more likely to develop hyperosmolar hyperglycemic nonketotic syndrome because with limited insulin, they can use enough glucose to prevent ketosis but not enough to maintain a normal blood glucose level.

To confirm an acid-base imbalance, it is necessary to assess which findings from a client's arterial blood gas (ABG) results? Select all that apply.

pH PaCO2 HCO3 Explanation: Arterial blood gas (ABG) results are the main tool for measuring blood pH, CO2 content (PaCO2), and bicarbonate (HCO3). The two types of acid-base imbalances are acidosis and alkalosis.

A nurse assesses arterial blood gas results for a patient in acute respiratory failure (ARF). Which results are consistent with this disorder?

pH 7.28, PaO2 50 mm Hg Explanation: ARF is defined as a decrease in arterial oxygen tension (PaO2) to less than 60 mm Hg (hypoxemia) and an increase in arterial carbon dioxide tension (PaCO2) to >50 mm Hg (hypercapnia), with an arterial pH less than 7.35.

When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis?

pH 7.48 Explanation: Metabolic alkalosis is a clinical disturbance characterized by a high pH and high plasma bicarbonate concentration. The HCO value is below normal. The PaCO value and the oxygen saturation level are within a normal range.

The nurse is analyzing the arterial blood gas (ABG) results of a client diagnosed with severe pneumonia. Which of the following ABG results indicates respiratory acidosis?

pH: 7.20, PaCO2: 65 mm Hg, HCO3-: 26 mEq/L Explanation: Respiratory acidosis is a clinical disorder in which the pH is less than 7.35 and the PaCO2 is greater than 42 mm Hg and a compensatory increase in the plasma HCO3- occurs. It may be either acute or chronic. The ABG of pH: 7.32, PaCO2: 40 mm Hg, HCO3-: 18 mEq/L indicates metabolic acidosis. The ABGs of pH: 7.50, PaCO2: 30 mm Hg, and HCO3-: 24 mEq/L indicate respiratory alkalosis. The ABGs of pH 7.42, PaCO2: 45 mm Hg, and HCO3-: 22 mEq/L indicate a normal result/no imbalance.

A client admitted with acute anxiety has the following arterial blood gas (ABG) values: pH, 7.55; partial pressure of arterial oxygen (PaO2), 90 mm Hg; partial pressure of arterial carbon dioxide (PaCO2), 27 mm Hg; and bicarbonate (HCO3-), 24 mEq/L. Based on these values, the nurse suspects:

respiratory alkalosis. Explanation: This client's above-normal pH value indicates alkalosis. The below-normal PaCO2 value indicates acid loss via hyperventilation; this type of acid loss occurs only in respiratory alkalosis. These ABG values wouldn't occur in metabolic acidosis, respiratory acidosis, or metabolic alkalosis.