RN NCLEX Mastery Labs & Acid-Base Quiz
A male patient has the following lab results: arterial pH of 7.29, platelet count of 200,000, white blood cell (WBC) count of 8,000, and magnesium of 2.1. Which result is critical and should be reported to the physician immediately? 1- Arterial pH 2- Magnesium 3- Platelets 4- WBC count
1- Arterial pH Explanation • Normal arterial pH is 7.35 to 7.45. The patient is acidotic and needs immediate intervention to correct the pH imbalance. • Normal platelet count: 150,000 to 400,000. • Normal WBC count: 5,000 to 10,000. • Normal magnesium: 1.3 to 2.1 mEq/L.
The nurse is caring for a patient with severe liver disease. The patient becomes confused and combative. To assess for the presence of hepatic encephalopathy, the nurse would expect the physician to order a serum level of 1- ammonia 2- uric acid 3- urea 4- lactate
1- ammonia Explanation • Ammonia is a byproduct of protein catabolism. It is normally converted into urea and excreted, but in liver disease, ammonia is not converted and serum levels rise. • A rise in ammonia levels is toxic to the brain and can cause encephalopathy. In hepatic encephalopathy, as ammonia levels rise, patients become confused and agitated and may become aggressive. • Incorrect: Uric acid, urea, and lactate are not associated with hepatic encephalopathy.
A 5-year-old boy is admitted due to abdominal pain and diarrhea. The patient's physical exam reveals poor skin turgor and dry mucous membranes. The nurse anticipates which laboratory result? 1- Decreased sodium. 2- Elevated hematocrit. 3- Decreased platelets. 4- Elevated potassium.
2- Elevated hematocrit. Explanation • The patient is dehydrated, causing hemoconcentration and an increased hematocrit. • Incorrect: The sodium level is more likely to increase due to fluid loss and subsequent concentration. • Incorrect: A patient with diarrhea is likely to experience hypokalemia. • Incorrect: Platelets should not be affected by infection.
A patient in the emergency room is admitted due to hypertension with a blood pressure of 160/100 mmHg. Blood test shows potassium level is at 5.5mEq/L, calcium is 9.2 mg/dl, and sodium is 139. ECG results show irregular cardiac rhythm. What imbalance is the patient experiencing? 1- Hypocalcemia 2- Hyperkalemia 3- Hypokalemia 4- Hypernatremia
2- Hyperkalemia Explanation • Normal potassium ranges from 3.5 to 5.0 mEq/L. This patient has hyperkalemia and is suffering from cardiac arrhythmias as a result. • Normal calcium ranges from 9 to 10.5 mg/dl. • Normal sodium typically ranges from 136 to 145 mEq/L.
A patient who has undergone neck surgery for removal of the parathyroid gland states that he is experiencing muscle twitching and spasms. The physician orders blood tests to confirm the diagnosis. The nurse expects that 1- phosphate levels are high 2- serum calcium levels are low 3- parathyroid hormone levels are low 4- serum calcium levels are high
2- serum calcium levels are low Explanation • Parathyroid hormone acts to increase serum calcium through the breakdown of bone. Removal of the parathyroid gland and low parathyroid hormone may cause hypocalcemia. • Hypocalcemia can cause muscle twitching, spasms, petechiae, and tingling.
The nurse is giving discharge instructions to a patient with diabetes mellitus regarding glycated hemoglobin (HbA1c). The nurse knows that the patient understands the teachings if the patient says 1- "I will monitor my HbA1c every morning before eating my breakfast." 2- "My capillary blood will be used to check for my HbA1c level." 3- "The HbA1c level is taken to monitor my long-term blood sugar control." 4- "The HbA1c level is repeated once every 4 weeks."
3- "The HbA1c level is taken to monitor my long-term blood sugar control." Explanation • HbA1c monitors long-term control of blood glucose levels. The diabetic goal is a HbA1c < 7%. • HbA1c measures the amount of glucose molecules that have reacted with a red blood cell over the lifespan of the cell (120 days). • Incorrect: HbA1c levels are done 2 to 4 times annually and reflect blood glucose control over the preceding three months. • Incorrect: Routine blood glucose checks use capillary blood and are done at least every morning.
The nurse is caring for a male patient with a hemoglobin level of 12.3 g/dL. The nurse would expect this hemoglobin level to be caused by 1- hyperthyroidism 2- diabetes mellitus 3- chronic renal failure 4- menstruation
3- chronic renal failure Explanation • The normal range of hemoglobin in males is 14 to 18 g/dL. • Chronic renal failure can cause decreased hemoglobin formation due to insufficient erythropoietin production. • Incorrect: Diabetes and hyperthyroidism are not associated with anemia. • Incorrect: Anemia can occur during menstruation due to blood loss; however, the patient in this scenario is a male.
A patient suspected of having tuberculosis needs a sputum culture and sensitivity. The nurse gives instructions to the patient regarding the proper collection of sputum. The nurse needs to give additional instructions if the patient says 1- "I need to cough deeply and expectorate directly into the collection cup." 2- "I should collect sputum in the morning to get an overnight collection of my sputum." 3- "I should avoid contaminating the sputum with other fluids." 4- "I must rinse my mouth with mouthwash before collecting sputum."
4- "I must rinse my mouth with mouthwash before collecting sputum." Explanation • Most mouthwashes are antibacterial. Rinsing the mouth with mouthwash or even water may destroy microbes and alter the culture. • The other answer choices describe proper sputum collection.
A patient has an arterial blood gas (ABG) done in the ER: pH 7.51, pCO2 49, pO2 85, HCO3 35. Which of the following describes this ABG? 1- Uncompensated metabolic acidosis 2- Compensated respiratory acidosis 3- Uncompensated metabolic alkalosis 4- Partially compensated metabolic alkalosis
4- Partially compensated metabolic alkalosis Explanation • Partially compensated metabolic alkalosis is correct because there is an increase in pH (alkalosis) and an increase in HCO3 (metabolic in origin). pCO2 is also elevated, which tells us the lungs are attempting to compensate but have not yet fully compensated.
The health care provider (HCP) suspects that the client with diabetes mellitus type II is experiencing metabolic acidosis. Which set of arterial blood gases indicate to the nurse that the client is having metabolic acidosis? 1- pH 7.55, pO₂ 90 mmHg, pCO₂ 50 mmHg, HCO₃ 33 mEq/L, SaO₂ 98% 2- pH 7.39, pO₂ 85 mmHg, pCO₂ 43 mmHg, HCO₃ 22 mEq/L, SaO₂ 97% 3- pH 7.31, pO₂ 90 mmHg, pCO₂ 67mmHg, HCO₃ 32 mEq/L, SaO₂ 98% 4- pH 7.29, pO₂ 85 mmHg, pCO₂ 35 mmHg, HCO₃ 17 mEq/L, SaO₂ 95%
4- pH 7.29, pO₂ 85 mmHg, pCO₂ 35 mmHg, HCO₃ 17 mEq/L, SaO₂ 95% Explanation To review ABG's, first check the pO₂ and SaO₂ to see the client's oxygenation status. Then assess for pH imbalance. A ph below 7.35 indicates acidosis, whereas a pH above 7.45 indicates alkalosis. Next look at whether the pCO₂ is high (acidotic), low (alkalotic) or normal. Finally. check whether the HCO₃ is high (alkalotic), low (acidotic), or normal. In metabolic acidosis, the pH is acidotic, below normal range of 7.35 to 7.45, and HCO₃ is acidotic, below normal range of 22 to 28 mmHg. This is acidosis caused by excess ketones, an acid, and decreased bicarbonate buffers. When determining the cause of the pH imbalance, think of the pneumonic "R.O.M.E", which stands for Respiratory Opposite Metabolic Equal. Respiratory is opposite of the pH if the imbalance is respiratory in nature (e.g. respiratory acidosis: pH low, pCO₂ high; respiratory alkalosis: pH high, pCO₂ low). If the pH imbalance is related to metabolic causes, the Metabolic (or HCO₃) Equals the pH (e.g. Metabolic acidosis: pH low and HCO₃ low; Metabolic alkalosis: pH high and HCO₃ high).
The nurse is caring for a client with end stage kidney disease (ESKD) on dialysis. The client asks why no milk, chocolate milk, or soft drinks are allowed in the diet order. The nurse explains that these foods should be avoided to decrease the risk of which conditions? 1- Hypernatremia 2- Hyponatremia 3- Hypercalcemia 4- Hypophosphatemia 5- Hyperphosphatemia 6- Hypocalcemia
5- Hyperphosphatemia 6- Hypocalcemia Explanation • In clients with significant kidney disease, the kidneys do not excrete enough phosphate. Dialysis helps clear the blood of waste products, urea, creatinine, and uricacid, but does not remove phosphate effectively. For this reason, clients with severe kidney disease are at risk for hyperphosphatemia even when they are given dialysis. • Hyperphosphatemia is treated by reducing dietary intake of phosphate and by administration of drugs called phosphate-binders, which reduce absorption of dietary phosphate. Foods high in phosphate, such as milk, egg yolks, chocolate, and soft drinks, are avoided. Other foods high in phosphate include organ meats, dried beans, bran cereals, and beer. • As phosphate levels rise, serum calcium lowers as the calcium is consumed in the formation of calcium phosphate. Phosphate also inhibits vitamin D hydroxylation by the kidneys. Vitamin D acts to increase dietary calcium absorption, so hyperphosphatemia contributes to hypocalcemia in this way as well. • Hyperphosphatemia alone does not usually cause symptoms, but in clients with kidney disease high phosphate accompanies low calcium. Hypocalcemia can cause muscle cramps and spasms (tetany), tingling (often in the face or fingers), seizures, or abnormal heart rhythms. • Hypernatremia is associated with kidney disease, but sodium levels are not affected much by these foods. High sodium and the excess fluid that goes with it is managed with dialysis.
The nurse draws blood from a client with acute chest pain and nausea. The nurse notifies the health care provider (HCP) of which of the client's laboratory results? A- Troponin-1 0.025 ng/mL B- Myoglobin 180 mcg/L C- CK-MB 0% D- BNP 70 ng/mL
A- A troponin-1 level of 0.01 ng/mL is within the normal troponin-1 range of <0.035 ng/mL. A troponin-I level above the normal range of less than 0.035 ng/mL may indicate mycardial injury or infarction. *Answer B*- A myoglobin level of 180 mcg/L is above the normal range of less than 90 mcg/L. While myoglobin levels may elevate approximately 2 hours fter cardiac ischemia or infarction, they are not specific to cardiac muscles. C- CKMB levels greater than 0% may indicate myocardial ischemia or infarction. CKMB levels may start elevating approximately 3 hours after cardiac ischemia or infarction, and help determine the presence of an MI along with a 12 lead EKG. D- A BNP of 70 ng/mL is within the normal range of < 100 ng/mL. Elevated BNP levels indicate increased stretching of the cardiac wall and may indicate ventricular dysfunction. Explanation Any troponin-I level greater than 0.03 ng/mL indicates myocardial damage.Troponin-I is more specific for cardiac muscle injury than CK-MB and elevates 4 to 6 hours after infarction. When a client reports chest pain, serum cardiac enzymes are tested and a 12 lead EKG is performed. Cardiac enzyme laboratory panels include several different markers that may indicate muscle damage including creatine kinase-MB (CK-MB), creatine kinase, myoglobin, and troponin. CK-MB and troponin-I are cardiac muscle-specific enzymes, meaning that they are not easily elevated by other muscle breakdown such as occurs with seizures or rhabdomyolysis.
A nurse on a medical unit is assigned patients with acid-base irregularities. While caring for a client with gastric lavage or prolonged vomiting, the nurse should assess for A- alkalosis B- loss of osmotic pressure C- acidosis D- reduction in hemoglobin
A- alkalosis Explanation • Gastric lavage and persistent vomiting both involve the loss of gastric contents and hydrochloric acid from within the stomach, which may lead to metabolic alkalosis. • Incorrect: Gastric lavage and vomiting will not affect hemoglobin levels. • Incorrect: Osmotic pressure is disturbed when protein is lost from the body.
A patient with Type 1 diabetes is in the ER after being found unconscious. The nurse notes the patient's breath is fruity. Which of the following arterial blood gases does the nurse expect to see? A- pH 7.28, pCO2 40, HCO3 16 B- pH 7.38, pCO2 45, HCO3 26 C- pH 7.49, pCO2 50, HCO3 18 D- pH 7.31, pCO2 60, HCO3 29
A- pH 7.28, pCO2 40, HCO3 16 Explanation • This patient is in diabetic ketoacidosis. This is supported by the history of Type 1 diabetes, the fact of being found unconscious, and the fruity breath. • You would expect a low pH due to acidosis, a normal pCO2 (if uncompensated) or low pCO2 (if compensated), and a low HCO3, as this is metabolic in origin. Metabolic Acidosis: • Caused by loss of bicarb or a build up of acids: lactic acidosis, diarrhea, renal failure, ketones, or ammonium intoxication. Not caused by respiration. • HCO3 decreases, pH decreases • Compensation: hyperventilation to eliminate CO2 Respiratory Acidosis: • Respiratory system is the cause • Increase in pCO2, decrease in pH • Compensation: kidneys reabsorb bicarb (HCO3)
A right shift of the oxygen-hemoglobin dissociation curve favors oxygen release to tissues. What causes this right shift to occur? SATA 1- decreased pH 2- Increased pCO2 3- Increased 2, 3-DPG 4- Exercise
All answer choices are correct. Explanation Factors that move the oxygen dissociation curve to the right are physiological states in which tissues need more oxygen. For example, during exercise, muscles have a higher metabolic rate and consequently need more oxygen and produce more carbon dioxide and lactic acid. Their temperature also rises. CO binds to Hb better than oxygen; therefore, it interferes with oxygen unloading from Hb. Oxygen-hemoglobin dissociation curve: • Left Shift (oxygen uptake) — increased pH — decreased 2, 3-DPG — lower temperature — increased CO — pCO2 decreased • Right Shift (oxygen release) — decreased pH — increased 2, 3-DPG — increased temperature — decreased CO — pCO2 increased
The nurse is caring for male patient with sepsis. He weighs 90 kg and his urine output has been 175 mL over 6 hours. The nurse suspects acute kidney injury (AKI) when the creatinine is A- 1.2 mg/dL B- 1.9 mg/dL C- 0.9 mg/dL D- 0.3 mg/dL
B- 1.9 mg/ Explanation • Acute kidney injury (AKI) describes the abrupt loss of kidney function resulting in the retention of urea and other nitrogenous waste products and causing dysregulation of extracellular volume and electrolytes. • AKI is diagnosed by an increase in serum creatinine of 0.3 mg/dL or >50% over normal and a urine output of <0.5 mL/kg/hour for >6 hours. • Correct: Creatinine 1.9 mg/dL is indicative of renal failure. • Normal range for creatinine is 0.6 to 1.2 mg/dL (male) or 0.5 to 1.1 mg/dL (female). • In general, blood urea nitrogen (BUN) and creatinine increase together, but because BUN often increases for other reasons, it is used as a supporting indicator of AKI rather than a diagnostic sign.
The nurse is reviewing the lab results of a patient taking warfarin for atrial fibrillation. Which of the following INR values would the nurse consider therapeutic for this patient? A- 1.8 B- 3.1 C- 2.4 D- 0.8
C- 2.4 Explanation • The INR is used to monitor patients on warfarin or related anticoagulant medications. The normal range is 0.8 to 1.2. • Patients requiring anticoagulation for atrial fibrillation have a target INR range of 2.0 to 3.0 to reduce the risk of blood clots. The higher the INR, the higher the risk of bleeding. • Incorrect: The other options do not fall into the target range of 2.0 to 3.0.
While educating a patient about lifestyle changes to decrease total cholesterol, the nurse tells the patient that the goal for total cholesterol is less than A- 250 mg/dL B- 60 mg/dL C- 200 mg/dL D- 130 mg/dL
C- 200 mg/dL Explanation • Total cholesterol should be maintained below 200 mg/dL. This will lower the risk of coronary artery disease. • HDLs should be above 60 mg/dL. • LDLs should be below 130 mg/dL.
The nurse is caring for a patient on bed rest. The patient receives low-dose heparin daily for the prevention of deep-vein thrombosis (DVT). The nurse evaluates the patient's aPTT level. Which of the following aPTT levels not within the therapeutic range? A- 60 seconds B- 65 seconds C- 50 seconds D- 35 seconds
D- 35 seconds Explanation • The reference range for aPTT is 30 to 40 seconds. • For treatment of DVT with low-molecular-weight heparin (LMWH), a therapeutic range of aPTT ratio (patient/control) of 1.5 to 2.5 is generally recommended. This results in an aPTT ranging from 45 to 100 seconds. • Anything less than 45 seconds is under the therapeutic value. • The activated partial thromboplastin time (aPTT) has replaced partial thromboplastin time (PTT). They both measure the efficacy of the intrinsic and common coagulation pathways in patients treated with heparin.
The nurse observes the following arterial blood gases: pH 7.49, pCO2 41, HCO3 38. The nurse understands that the patient has which acid-base imbalance? 1- Compensated metabolic alkalosis 2- Uncompensated metabolic alkalosis 3- Uncompensated metabolic acidosis 4- Compensated respiratory acidosis
Explanation • Uncompensated metabolic alkalosis is correct because there is an increase in pH (alkalosis), an increase in HCO3 (metabolic in origin), and pCO2 is normal (this tells us the lungs are not compensating). Respiratory Acidosis: • Respiratory system is the cause • Increase in pCO2, decrease in pH • Compensation: kidneys reabsorb bicarb (HCO3) Metabolic Acidosis: • Caused by loss of bicarb or buildup of acids: lactic acidosis, diarrhea, renal failure, ketones, ammonium intoxication. Not caused by respiration. • HCO3 decreases, pH decreases • Compensation: hyperventilation to eliminate CO2 Respiratory Alkalosis: • Caused by excessive ventilation • Decrease in pCO2, increase in pH • Compensation: kidneys excrete HCO3 Metabolic Alkalosis: • Acid (H+) lost from emesis, diuretics. Retention of HCO3 from medications, hyperaldosteronism • Increase in HCO3, increase in pH • Compensation: respiratory centers are not stimulated, leading to hypoventilation and CO2 retention
