Acid/Base Balance Content Post Test- HURST

A client who had a cerebral vascular accident (CVA) is now having Cheyne-Stokes respirations ranging from 12-30 breaths/minute. BP 158/108, HR 46. Based on this assessment, which acid/base imbalance does the nurse anticipate that this client will develop? Choose One 1. Respiratory acidosis 2. Respiratory alkalosis 3. Metabolic acidosis 4. Metabolic alkalosis

1 Rationale 1. Correct: Causes of respiratory acidosis include any causes of decreased respiratory drive, such as drugs (narcotics) or central nervous system disorders. With a massive cerebral vascular accident (CVA or stroke), the respiratory center in the brain is impaired and affects oxygenation. Cheyne-Stokes respirations are characterized by progressively deeper and sometimes faster respirations followed by periods of apnea. This leads to acidosis and often times respiratory arrest. 2. Incorrect: Respiratory alkalosis includes hyperventilation and tachypnea which does not describe the characteristics of Cheyne-Stokes respirations. 3. Incorrect: Compensation for metabolic acidosis caused by disorders like DKA includes tachypnea with deep respirations called Kussmaul's respirations. Here, we have a respiratory problem, not a problem that started with a metabolic issue. 4. Incorrect: The most common cause of metabolic alkalosis is vomiting, and this is clearly a respiratory problem, not metabolic.

A client, admitted to the surgical unit post left thoracotomy, is drowsy. Vital signs on admit are T 99.8ºF (37.6ºC), HR 94, R 16/shallow, BP 100/68. ABGs are pH 7.33, PCO2 48, HCO3 24. What action should the nurse initiate? Choose One 1. Have client take deep breaths. 2. Administer naloxone. 3. Tell the client to breathe faster. 4. Medicate for pain.

1 Rationale 1. Correct: This client had chest surgery and the pCO2 is high. What are you worried about? Hypoventilation. Yes, the client is probably hurting due to the incision and does not want to take deep breaths. In order to get rid of the excess CO2 the client needs to turn, cough, and deep breathe. Incentive spirometry can be provided to assist the client with this effort. 2. Incorrect: This client has mild respiratory acidosis after surgery. The nurse can fix this by waking the client up and instructing the client to take deep breaths or have the client use incentive spirometry. 3. Incorrect: Breathing faster will only work for a few minutes. The problem is the client needs to breathe deeper to get more oxygen to the tissue and more CO2 out of the lungs. Hyperventilating will lead to respiratory alkalosis. 4. Incorrect: No more sedation! The client is not breathing enough. This client needs to take deep breaths.

The emergency department nurse is monitoring a client being admitted in diabetic ketoacidosis (DKA). Which arterial blood gas value would be expected? Select All That Apply 1. pH 7.32 2. PaCO2 32 3. HCO3 25 4. PaO2 78 5. SaO2 82

1, 2 Rationale 1., &2. Correct: In DKA, the client is acidotic. Normal pH is 7.35-7.45. A pH of 7.32 indicates acidosis and will be expected for a client in DKA. Normal PaCO2 is 35-45. Remember CO2 is considered an acid. The client in DKA will have an increased respiratory rate, so the PaCO2 will either be normal or low. This value of 32 is low and is an expected finding as the body is compensating for the acidosis. 3. Incorrect: Normal HCO3 is 22-26. HCO3 is a base. Initially, the acids bind to the bicarb to reduce the acid levels. Therefore, the HCO3 would be less than 22. So, in DKA, the expected initial finding is a low HCO3?. Keep in mind that with acidosis, as the body compensates later, the kidneys will retain bicarb and you will see the bicarb levels increase. 4. Incorrect: Normal PaO2 is 80-100. An expected finding in DKA will be normal or increased PaO2, not decreased. 5. Incorrect: The client in DKA is kussmauling to blow off the CO2 (acid), so the oxygen saturation of blood will be high if there is no respiratory issue. In this question you are not told that there is a respiratory problem, so you would not expect a low oxygen saturation level.

How would the nurse interpret this client's Arterial Blood Gas (ABG) results? pH 7.30 PaCO2 55 mm Hg Bicarb 25 mEq/liter PaO2 93 mm Hg SaO2 95% Select All That Apply 1. Respiratory acidosis 2. Respiratory alkalosis 3. Metabolic acidosis 4. Metabolic alkalosis 5. Uncompensated 6. Partially compensated 7. Fully compensated

1, 5 Rationale 1., & 5. Correct. Now will a pH of 7.30 make the patient have acidosis or alkalosis? Well it's less than 7.35 so that's a low pH, and you know that a low pH is acidosis. So now we know acidosis, but we still must figure out if it is respiratory or metabolic. Look at the PaCO2, it is 55. That's a lot of CO2, and it's greater than the normal range of 35-45, so the PaCO2 must be acidosis. Now the Bicarb is 25, and a Bicarb of 25 is within the normal range of 22-26. To determine whether this is respiratory or metabolic acidosis, we need to match the pH with either the PaCO2 or the HCO3. The pH that we're trying to match is acidosis, so keep in mind you're trying to match the word acidosis with one of the chemicals. Well look at our problem, the CO2 is also acidosis. So, since these two match and they are both acidosis, we can say this is clearly Respiratory Acidosis because the "respiratory" chemical (CO2) is the one that matches the pH. Now, look at the Bicarb level. The bicarb is normal and doesn't match our pH which is acidosis, so, we can just mark it out. There you have it; this is Respiratory Acidosis. So, is there any compensation going on? No, not yet. The bicarb is still within normal limits. These values indicate uncompensated respiratory acidosis. 2. Incorrect. The pH would need to be above 7.45 and the PaCO2 below 35 for the client to have respiratory alkalosis. 3. Incorrect. The pH would need to be below 7.35 and the Bicarb below 22 for the client to have metabolic acidosis. 4. Incorrect. The pH would need to be above 7.45 and the Bicarb above 26 for the client to have metabolic alkalosis. 6. Incorrect. When partial compensation begins, the bicarb level will be above 26 as it goes UP to put more base in the body. 7. Incorrect. Full compensation will occur when the pH comes back to normal.

A client who has been given steroids for a prolonged period to treat asthma, reports dizziness, tingling of the fingers, and muscle weakness. What action should the nurse take first? Choose One 1. Determine current blood pressure 2. Connect client to a cardiac monitor 3. Administer oxygen 4. Obtain arterial blood gases

2 Rationale 2. Correct. These symptoms are indicative of hypokalemia and metabolic alkalosis. What do steroids do to the body? Steroids make you retain sodium and excrete potassium. So, you could become hypokalemic. Low potassium levels cause an increase in the reabsorption of bicarb by the kidneys. That is why you sometimes see metabolic alkalosis with Cushing's disease and prolonged steroid use. What electrolyte imbalance do we see with metabolic alkalosis? It's hypokalemia. So, if you have a client who is hypokalemic then they may have muscle weakness, hypotension and life threatening arrhythmias. And we know when the potassium is messed up, we should always think about the heart first. Connect the client to the cardiac monitor. 1. Incorrect. The priority is going to be checking the heart rhythm because a low potassium can cause a life-threatening arrhythmia. 3. Incorrect. The symptoms are most likely due to low potassium levels. This could lead to life-threatening arrhythmias. How would you fix this problem? Yes, give potassium, not oxygen. 4. Incorrect. You can do this after you check the heart rhythm. The priority is going to be checking the heart rhythm because a low potassium can cause a life-threatening arrhythmia.

A client presents to the emergency department (ED) with flu symptoms, fever, and chills. The nurse notes that the vital signs are: T 102.8°F (39.3°C), P 128, RR 30, B/P 154/88. ABG results are: pH-7.5, PaCO2 32, HCO3 23. What acid/base imbalance does the nurse determine that this client has developed? Choose One 1. Respiratory acidosis 2. Respiratory alkalosis 3. Metabolic acidosis 4. Metabolic alkalosis

2 Rationale 2. Correct: This client has a high fever. Hyperventilation due to anxiety, pain, shock, severe infection, fever, and liver failure can lead to respiratory alkalosis. Here, the ABGs reflect respiratory alkalosis. pH > 7.45, PCO2 < 35, HCO3 normal. 1. Incorrect: The client is hyperventilating so CO2 (acid) is being blown off. The pH says alkalosis.3. Incorrect: Not a metabolic problem since the HCO?3 is in normal range and remember the pH says alkalosis.4. Incorrect: Not a metabolic related acid/base imbalance since the HCO3 is in normal range.

How would the nurse interpret this client's Arterial Blood Gas (ABG) results? pH 7.35 PaCO2 30 mm Hg Bicarb 19 mEq/liter PaO2 89 mm Hg SaO2 90% Select All That Apply 1. Respiratory acidosis 2. Respiratory alkalosis 3. Metabolic acidosis 4. Metabolic alkalosis 5. Uncompensated 6. Partially compensated 7. Fully compensated

3, 7 Rationale 3., & 7. Correct. These ABG values indicate metabolic acidosis. The pH is normal, but it is on the acidosis side of normal at 7.35. Now, which other chemical says acidosis? Look at the bicarb; the bicarb is low, indicating acidosis so there's your match! The bicarb matches the pH. What chemical problem does the bicarb relate to - respiratory or metabolic? It's metabolic. Metabolic acidosis. Has compensation begun? Yes. The lungs are compensating for the metabolic acidosis by getting rid of CO2, which is an acid. Therefore, the PaCO2 is below the normal range of 35-45. Since the pH is normal, full compensation has occurred. 1. Incorrect. For this problem to indicate respiratory acidosis, the pH would need to be less than 7.35 (or if fully compensated, the pH would be less than 7.40 to be on the acidotic side of normal) and the CO2 would need to be greater than 45. In this problem, we see the CO2 has been blown off to help get rid of the acid. 2. Incorrect. This is not a respiratory problem. The lung chemical, carbon dioxide does not match the acidotic pH. The pH indicates acidosis, not alkalosis. 4. Incorrect. Metabolic alkalosis would have pH greater than 7.45 (or if fully compensated, the pH would be greater than 7.40 to be on the alkalotic side of normal) and a Bicarb level greater than 26. The pH is on the acidosis side of normal, and the bicarb (metabolic chemical) indicates acidosis here. The lungs have compensated by bringing down the CO2 level to decrerase the acidotic state. 5. Incorrect. The pH is normal even though the PaCO2 and the bicarb values are abnormal so compensation has occurred. The pH would be abnormal and the PaCO2 would be normal if compensation had not begun. This client has fully compensated. 6. Incorrect. The pH is normal even though the PaCO2 and the bicarb values are abnormal so compensation has occurred. With partial compensation, the pH, PaCO2, and bicarb would all be abnormal. This client has fully compensated.

A client arrives at the clinic with reports of persistent vomiting, weakness and leg cramps. The nurse notes that the client is irritable. BP 102/58, HR 108, RR 14. Based on this data, what acid/base imbalance does the nurse expect? Choose One 1. Respiratory acidosis 2. Respiratory alkalosis 3. Metabolic acidosis 4. Metabolic alkalosis

4 Rationale 4. Correct: Symptoms of alkalosis are often due to associated potassium loss and may include irritability, weakness, and cramping. Excessive vomiting eliminates gastric acid and potassium, leading to metabolic alkalosis. 1. Incorrect: Respiratory Acidosis signs and symptoms include decreased respiratory rate, hyportension and a decrease in level of consciousness. Remember, if it's respiratory acidosis, it traces back to the lungs. This problem describes a metabolic issue. 2. Incorrect: Repiratory Alkalosis signs and symptoms include an inability to concentrate, light-headedness, numbness and tingling, tinnitus and loss of consciousness. The loss of CO2 from the lungs would be the problem with respiratory alkalosis, but the problem described in the question is metabolic. 3. Incorrect: Metabolic Acidosis signs and symptoms include headache, confusion, increased respiratory rate and depth, drowsiness, and nausea and vomiting. This can occur in cases of diarrhea, when more bicarb is lost through the lower GI tract.

Which initial arterial blood gas (ABG) results would the nurse likely see in a client who has overdosed on acetylsalicylic acid (ASA)? Choose One 1. pH 7.50, PaCO2 42, PaO2 63, SaO2 91, HCO3 28 2. pH 7.32, PaCO2 36, PaO2 83, SaO2 95, HCO3 19 3. pH 7.28, PaCO2 28, PaO2 72, SaO2 90, HCO3 16 4. pH 7.48, PaCO2 30, PaO2 88, SaO2 92, HCO3 24

4 Rationale 4. Correct: This ABG result indicates respiratory alkalosis. Initially, acetylsalicylic acid stimulates the respiratory center and causes an increase in respiratory rate and depth. This causes respiratory alkalosis by blowing off CO2 and causing the pH to increase. Losing CO2 (acid) makes the client more alkalotic, which is reflected with an increased pH, decreased PaCO?2 and normal HCO?3. 1. Incorrect: This ABG result indicates metabolic alkalosis. The pH is high, PaCO?2 is normal and HCO?3 is high. Normal pH is 7.35-7.45, normal PaCO?2 is 35-45, normal HCO?3 is 22-26. 2. Incorrect: The client with an initial aspirin overdose will have a respiratory alkalosis. This ABG result indicates metabolic acidosis. The pH is less than 7.35 (acidotic); the PaCO2 is within normal limits, and the bicarb is low (less than 22), which creates acidosis. 3. Incorrect: This ABG indicates partially compensated metabolic acidosis. The problem in the stem would initially result in a respiratory problem. The pH is low (acidosis). The PaCO2 is low (alkalosis) as the body tries to compensate by decreasing the acid in the body. The metabolic chemical, bicarb, is low (acidosis) which matches the acidotic pH. Since the pH, PaCO2, and bicarb are all abnormal, we know that partial compensation has occurred.

How would the nurse interpret this client's Arterial Blood Gas (ABG) results? pH 7.44 PaCO2 51 mm Hg Bicarb 31 mEq/liter PaO2 91 mm Hg SaO2 91% Select All That Apply 1. Respiratory acidosis 2. Respiratory alkalosis 3. Metabolic acidosis 4. Metabolic alkalosis 5. Uncompensated 6. Partially compensated 7. Fully compensated

Rationale 4., & 7. Correct. The pH is on the alkalosis side of normal (7.35-7.45). Anything above 7.0 is on the alkalotic side of normal. Look at the CO2. The CO2 is high, which indicates acidosis, so this does not match the alkalotic pH, does it? No. Look at the Bicarb. The bicarb is high, indicating alkalosis, so there is your match. The bicarb is higher than 26, so there is a lot of base in the body. So, this is metabolic alkalosis. Has compensation begun? Yes. The PaCO2 is high. The lungs are attempting to compensate by holding on to carbon dioxide, an acid, to make the pH normal. Since the pH is normal, full compensation has occurred. 1. Incorrect. For this problem to indicate respiratory acidosis, the pH would need to be less than 7.35 (or less than 7.40 if fully compensated to be on the acidotic side of normal) and the CO2 would need to be greater than 45. This pH does not indicate acidosis, so the lungs are not the problem. The lungs are compensating for a metabolic problem. 2. Incorrect. This is not a respiratory problem. The lung chemical, carbon dioxide is high, which would cause acidosis. However, this does not match the alkalotic pH. The pH indicates alkalosis, not acidosis. 3. Incorrect. The pH would need to be below 7.35 (or if fully compensated, the ph would be less than 4.0 to be on the acidotic side of normal) and the Bicarb below 22 for the clint to have metabolic acidosis. 5. Incorrect. The pH is normal even though the PaCO2 and the bicarb values are abnormal, so compensation has occurred. The pH would be abnormal and the PaCO2 would be normal if compensation had not begun. This client has fully compensated. 6. Incorrect. The pH is normal even though the PaCO2 and the bicarb values are abnormal so compensation has occurred. With partial compensation, the pH, PaCO2, and bicarb would all be abnormal. This client has fully compensated.