NUR 397 Chapter 12: Care of Pt with Acid Base problems

A patient is admitted with chronic anemia. What physiologic imbalance does the nurse suspect the patient is at risk of developing? 1.) Acidosis 2.) Alkalosis 3.) Hypokalemia 4.) Ineffective ventilation

1 Protein buffers, especially hemoglobin buffers, are the primary buffer of hydrogen ions. When patients are anemic, there is less hemoglobin to buffer hydrogen ions and a reduced ability for the body to prevent acidosis. There is no information that suggests the patient is at risk for ineffective ventilation, hypokalemia, or alkalosis.Test-Taking Tip: Watch for grammatical inconsistencies. If one or more of the options is not grammatically consistent with the stem, the alert test taker can identify it as a probable incorrect option. When the stem is in the form of an incomplete sentence, each option should complete the sentence in a grammatically correct way.

What is one of the causes of respiratory alkalosis? 1.) Anxiety 2.) Antacid use 3.) Kidney failure 4.) Diuretic therapy

1 Hyperventilation is one cause of respiratory alkalosis, which can result from fear and anxiety. Kidney failure and diuretic therapy are not causes of respiratory alkalosis. The use of antacids can result in metabolic alkalosis.

The nurse is caring for a group of patients with acidosis. The nurse recognizes that Kussmaul respirations are consistent with which situation? 1.) Aspirin overdose 2.) Use of hydrochlorothiazide 3.) Administration of sodium bicarbonate 4.) Patient receiving mechanical ventilation

1 If acidosis is metabolic in origin, the rate and depth of breathing increase as the hydrogen ion level rises; this is known as Kussmaul respiration. Metabolic acidosis is caused by alcoholic beverages, methyl alcohol, and acetylsalicylic acid (aspirin). Mechanical ventilation is used to correct hypoxemia and hypercapnia (elevated Paco 2). Hydrochlorothiazide causes metabolic alkalosis. Sodium bicarbonate is used in the treatment of metabolic acidosis; administration of this buffer may cause metabolic alkalosis.Test-Taking Tip: The presence of absolute words and phrases can also help you determine the correct answer to a multiple-choice item. If answer choices contain an absolute (e.g., none, never, must, cannot), be very cautious. Remember that there are not many things in the world that are absolute, and in an area as complex as nursing, an absolute may be a reason to eliminate it from consideration as the best choice. This is only a guideline and should not be taken to be true 100% of the time; however, it can help you reduce the number of choices.

A diabetic patient shows symptoms of diabetic ketoacidosis. What mechanism causes acidosis in this patient? 1.) Overproduction of hydrogen ions 2.) Underelimination of hydrogen ions 3.) Overelimination of bicarbonate ions 4.) Underproduction of bicarbonate ions

1 In diabetic ketoacidosis, there is an excessive breakdown of fatty acids. This produces strong acids (ketoacids) with the release of large amounts of hydrogen ions. Underelimination of hydrogen ions occurs when hydrogen ions are produced at normal rates, but their elimination is reduced. This is seen in patients with lung and kidney problems. Bicarbonate ion is made in the kidney or in the pancreas. In patients with impaired kidney or pancreatic function, there is underproduction of bicarbonate ions leading to acidosis. Overelimination of bicarbonate ions occurs when there is an excessive loss of bicarbonate ions. This occurs in diarrhea.

The nurse obtains lab results for a 50-year-old patient with the following results: pH 7.24; bicarbonate 20; PaO 2 82; PaCO 2 35. These findings are consistent with which acid-base imbalance? 1.) Metabolic acidosis 2.) Metabolic alkalosis 3.) Respiratory acidosis 4.) Respiratory alkalosis

1 In metabolic acidosis, there is a decrease in pH (normal is 7.35-7.45), a decrease in bicarbonate (normal is 21-28), a normal PaO 2 (normal is 80-100), and a normal or decreased PaCO 2 (normal is 35-45). The arterial blood gas results of pH 7.24; bicarbonate 20; PaO 2 82; PaCO 2 35 reflect metabolic acidosis. In metabolic alkalosis, there is an increase in pH, increase bicarbonate, normal PaO 2, and normal PaCO 2. In respiratory alkalosis, there is an increase in pH, a normal bicarbonate, a normal PaO 2, and a decrease in PaCO 2 In respiratory acidosis, there is an in decrease in pH, normal bicarbonate, normal PaO 2, and increased PaCO 2.STUDY TIP: Record the information you find to be most difficult to remember on 3" × 5" cards and carry them with you in your pocket or purse. When you are waiting in traffic or for an appointment, just pull out the cards and review again. This "found" time may add points to your test scores that you have lost in the past.

Which conditions can cause metabolic acidosis? Select all that apply. 1.) Diarrhea 2.) Liver failure 3.) Kidney failure 4.) Airway obstruction 5.) Respiratory depression

1,2,3 Diarrhea, liver failure, and kidney failure can result in metabolic acidosis. Airway obstruction and respiratory depression may result in respiratory acidosis.

A patient has been poisoned by botulinum toxins. What assessment findings suggest the patient has acidosis? Select all that apply. 1.) Confusion 2.) Hypertension 3.) Hyperreflexia 4.) Warm, flushed, dry skin 5.) Pounding peripheral pulse

1,4 If the patient is confused and has a warm, flushed, and dry skin, it may indicate the patient has acidosis. Acidosis decreases the ability of excitable tissues in the blood vessels to respond adequately. So, there is vasodilation leading to hypotension rather than hypertension. Decrease in the ability of the excitable tissues in the muscles to respond adequately to stimulus and the hyperkalemia associated with acidosis reduce the muscle tone. This leads to hyporeflexia rather than hyperreflexia. Mild acidosis may increase the heart rate, but as the acidosis worsens and there is hyperkalemia, the heart rate decreases making the peripheral pulse hard to find. Therefore the peripheral pulse is thready rather than pounding.

When caring for a group of patients at risk for respiratory acidosis, the nurse identifies which person as at highest risk? 1.) An athlete in training 2.) Patient who smokes cigarettes 3.) Person with uncontrolled diabetes 4.) Pregnant woman with hyperemesis gravidarum

2 Cigarette smoking worsens gas exchange, leading to disorders that contribute to hypoventilation and respiratory acidosis. An athlete in training should be healthy with optimal lung function, not respiratory acidosis. Hyperemesis gravidarum is characterized by nausea and vomiting, and vomiting causes metabolic alkalosis. Uncontrolled diabetes may result in diabetic ketoacidosis, which causes metabolic acidosis.Test-Taking Tip: The most reliable way to ensure that you select the correct response to a multiple-choice question is to recall it. Depend on your learning and memory to furnish the answer to the question. To do this, read the stem, and then stop! Do not look at the response options yet. Try to recall what you know and, based on this, what you would give as the answer. After you have taken a few seconds to do this, then look at all of the choices and select the one that most nearly matches the answer you recalled. It is important that you consider all the choices and not just choose the first option that seems to fit the answer you recall. Remember the distractors. The second choice may look okay, but the fourth choice may be worded in a way that makes it a slightly better choice. If you do not weigh all the choices, you are not maximizing your chances of correctly answering each question.

When caring for a patient with kidney failure who has metabolic acidosis, which symptom does the nurse expect as evidence of the body's compensatory effort? 1.) Pallor and diaphoresis 2.) Rapid and deep respirations 3.) Bradycardia and bounding pulse 4.) Hypotension and weak, thready pulse

2 Kussmaul respirations (rapid, deep respirations) represent the body's attempt to compensate for metabolic acidosis. The skin is warm, dry, and flushed in metabolic acidosis. Cardiovascular symptoms may occur, but they are manifestations of acidosis, not evidence of compensation.

The nurse is caring for a patient with hypoxemia and metabolic acidosis. Which task can be delegated to the nursing assistant who is helping with the patient's care? 1.) Assess the patient's respiratory pattern. 2.) Apply the pulse oximeter for continuous readings. 3.) Increase the intravenous normal saline to 120 mL/hr. 4.) Titrate O 2 to maintain an O 2 saturation of 95% to 100%.

2 Placing a peripheral pulse oximeter is a standardized nursing skill that is within the scope of practice for unlicensed personnel. Assessment and intravenous therapy are skills performed by the professional nurse. Titration of O 2 requires assessment and intervention beyond the scope of practice of an unlicensed individual.Test-Taking Tip: Be aware that information from previously asked questions may help you respond to other examination questions.

The nurse is caring for a patient with metabolic alkalosis. What manifestations of metabolic alkalosis is the nurse likely to assess? Select all that apply. 1.) Decrease in heart rate 2.) Numbness around the mouth 3.) Increase in handgrip strength 4.) Presence of Kussmaul respiration 5.) Hyperactivity of deep tendon reflexes

2,5 Hypercalcemia occurs with alkalosis, which can cause hyperactivity of deep tendon reflexes. Alkalosis overexcites the nervous system leading to tingling or numbness around the mouth. Overstimulation of the nerves may cause contraction of skeletal muscles, but the contractions are weaker because of hypokalemia. Therefore there is a decrease in handgrip strength. Alkalosis increases myocardial irritability and increases the heart rate. Kussmaul respiration (deep and rapid involuntary breathing) is seen in metabolic acidosis with respiratory compensation.

When evaluating the laboratory results of a patient with diabetic ketoacidosis, which lab value indicates the body has fully compensated from this acid-base imbalance? 1.) Normal serum glucose 2.) Normal serum potassium 3.) Normal pH on arterial blood gases 4.) Normal bicarbonate on arterial blood gases

3 Arterial blood gas pH returns to normal when the body's compensatory efforts are fully effective. Glucose, potassium, and bicarbonate are affected by diabetic acidosis, but their return to normal is not an indicator of acid-base balance.

What is one of the causes of acidosis? 1.) Colitis 2.) Heart failure 3.) Kidney failure 4.)Excessive body fluids

3 Causes of acidosis include kidney failure, pancreatitis, liver failure, and dehydration. Excessive body fluids, heart failure, and colitis are causes of alkalosis.

A lab report for a 47-year-old patient shows the following results: pH 7.32; bicarbonate 24; PaO 2 77; PaCO 2 48. These findings are consistent with which acid-base imbalance? 1.) Metabolic acidosis 2.) Metabolic alkalosis 3.) Respiratory acidosis 4.) Respiratory alkalosis

3 In respiratory acidosis, there is a decrease in pH (normal is 7.35-7.45), a normal bicarbonate (normal is 21-28), a decreased PaO 2 (normal is 80-100), and an increased PaCO 2 (normal is 35-45). The arterial blood gas results of pH 7.32; bicarbonate 24; PaO 2 77; PaCO 2 48 reflect respiratory acidosis. In respiratory alkalosis, there is an increase in pH, a normal bicarbonate, a normal PaO 2, and a decrease in PaCO 2. In metabolic alkalosis, there is an increase in pH, increase bicarbonate, normal PaO 2, and normal PaCO 2. In metabolic acidosis, there is a decrease in pH, decrease bicarbonate, normal PaO 2, and normal PaCO 2.STUDY TIP: Answer every question. A question without an answer is the same as a wrong answer. Go ahead and guess. You have studied for the test and you know the material well. You are not making a random guess based on no information. You are guessing based on what you have learned and your best assessment of the question.

The nurse is reviewing assessment data for a patient who was admitted for emergency treatment of an acute asthmatic episode. Which assessment data suggest the patient is in an uncompensated acid-base imbalance? 1.) Anxious 2.) PaCO 2 of 30 mm Hg 3.) HCO 3- of 24 mEq/L 4.) Temperature of 101.5°F (38.6°C)

3 Kidney compensation for respiratory acid-base imbalance (PaCO 2 30 mm Hg) from the acute asthma episode is not yet evident in the arterial blood gas analysis (HCO 3- 24 mEq/L), resulting in an uncompensated acid-base imbalance state. The fever is most likely associated with increased metabolism and work of breathing. Anxiety is common and related to hypoxia (PaO 2 80 mm Hg) and difficulty breathing (wheezing). The decreased PaCO 2 of 30 mm Hg is associated with the increased respiratory rate and cause of the respiratory alkalosis.Test-Taking Tip: Have confidence in your initial response to an item because it more than likely is the correct answer.

A patient is admitted with severe diabetic ketoacidosis. Arterial blood gas results reveal a pH of 7.21. What is this patient's acidosis most likely in response to? 1.) Anaerobic metabolism 2.) Excessive intake of insulin 3.) Excessive breakdown of fatty acids 4.) Excessive intake of alcoholic beverages

3 Metabolic acidosis can result from the overproduction of hydrogen ions, underelimination of hydrogen ions, or insufficient bicarbonate ions. Excessive breakdown of fatty acids that occurs with diabetic ketoacidosis or starvation results in overproduction of hydrogen ions and metabolic acidosis. Anaerobic metabolism produces lactic acid as a cause of metabolic acidosis. Excessive intake of alcoholic beverages will also cause metabolic acidosis because of the high concentration of hydrogen ions in alcohol. Excessive intake of insulin will not result in diabetic ketoacidosis.Test-Taking Tip: Read carefully and answer the question asked; pay attention to specific details in the question.

A patient with diabetes mellitus is brought to the emergency department after vomiting for several days. The patient has rapid, deep respirations and a urine dipstick reveals ketonuria. Which process does the nurse suspect is occurring with this patient? 1.) Kidney compensation for metabolic acidosis 2.) Kidney compensation for metabolic alkalosis 3.) Respiratory compensation for metabolic acidosis 4.) Respiratory compensation for metabolic alkalosis

3 Patients with diabetes mellitus can develop metabolic acidosis. Respiratory compensation occurs through the lungs as the rate and depth of respirations increase in order to reduce hydrogen ion levels. Kidney compensation is not occurring.

Which acid-base imbalance does the nurse anticipate the patient with morbid obesity may develop? 1.) Metabolic acidosis 2.) Metabolic alkalosis 3.) Respiratory acidosis 4.) Respiratory alkalosis

3 Respiratory acidosis is related to CO 2 retention secondary to respiratory depression, inadequate chest expansion, airway obstruction, or reduced alveolar-capillary diffusion. Respiratory acidosis is common in morbidly obese patients who experience inadequate chest expansion owing to their size and work of breathing. Metabolic acidosis is related to overproduction of hydrogen ions, underelimination of hydrogen ions, underproduction of bicarbonate ions, and overelimination of bicarbonate ions. Metabolic alkalosis is related to loss of bicarbonate or buffers (i.e., vomiting or nasogastric suction). Respiratory alkalosis usually is caused by excessive loss of CO 2 through hyperventilation secondary to fever, central nervous system lesions, and salicylates.

Which assessment finding requires priority nursing intervention in a patient with metabolic or respiratory acidosis? 1.) Dry skin 2.) Rapid respiratory rate 3.) Lethargy and confusion 4.) Bradycardia with widened QRS complex

4 Cardiovascular manifestations that require priority nursing interventions are related to delayed electrical conduction; specifically bradycardia that may progress to heart block, tall T waves, widened QRS complex, and prolonged PR interval. Other changes like lethargy, confusion, rapid respiratory rate, and dry skin are important to address but may not require priority interventions.Test-Taking Tip: Being prepared reduces your stress or tension level and helps you maintain a positive attitude.

When caring for a patient with metabolic acidosis, what must the nurse keep in mind regarding acid-base chemistry? 1.) Acids bind free hydrogen ions in solution. 2.) Acetic acid (CH 3COOH) is a strong acid. 3.) Normally, blood is slightly acidic in nature. 4.) Fluids with lower pH have higher acidity.

4 Fluids with lower pH have a higher level of free hydrogen ions and therefore have higher acidity. Acids release hydrogen ions rather than bind with them when dissolved in water. Strong acids readily dissociate in water and release all of their hydrogen ions. Acetic acid (CH 3COOH) is a weak acid. When dissolved in water, it releases only one of its four hydrogen molecules. Normally, blood has a pH of between 7.35 and 7.45, so it is slightly alkaline.

After a motor vehicle crash, the nurse is consoling a patient in the emergency department who is hysterical and hyperventilating after being notified of the death of a family member. What acid-base imbalance is this patient likely to develop? 1.) Metabolic acidosis 2.) Metabolic alkalosis 3.) Respiratory acidosis 4.) Respiratory alkalosis

4 Hyperventilation leads to excessive loss of CO 2 and respiratory alkalosis. The patient will not develop respiratory acidosis, which is caused by hypoventilation, nor will the patient develop metabolic alkalosis or acidosis.

The nurse is assessing the laboratory profiles of patients with acid-base imbalances. Which patient diagnosis correctly correlates to the appropriate lab values? 1.) Patient A has metabolic alkalosis. 2.) Patient B has metabolic acidosis. 3.) Patient C has respiratory acidosis. 4.) Patient D has respiratory depression.

4 The normal laboratory value of arterial bicarbonate is 21 to 28 mEq/L. The nurse anticipates that patient A has metabolic acidosis because the arterial bicarbonate value of 16 mEq/L indicates a decrease in the bicarbonate levels. The normal laboratory value of venous bicarbonate is 24 to 29 mEq/L. The nurse suspects that patient B has metabolic alkalosis because the patient's venous bicarbonate value is 31 mEq/L. The normal laboratory value of arterial PaCO 2 is 35 to 45 mm Hg. The arterial PaCO 2 value of 30 mm Hg indicates that patient C has a risk of respiratory alkalosis. The normal laboratory value of arterial PaO 2 is 80 to 100 mm Hg. An arterial PaO 2 value of 60 mm Hg indicates respiratory depression.Test-Taking Tip: Chart/exhibit items present a situation and ask a question. A variety of objective and subjective information is presented about the patient in formats such as the medical record (e.g., laboratory test results, results of diagnostic procedures, progress notes, health care provider orders, medication administration record, health history), physical assessment data, and assistant/patient interactions. After analyzing the information presented, the test taker answers the question. These questions usually reflect the analyzing level of cognitive thinking.In a clinical exam, you may be expected to select instruments, arrange instruments, and/or perform some other task. Acquaint yourself with the physical facility. If the required procedures are not clear to you, ask for clarification.

The lab values for a patient admitted for an exacerbation of chronic obstructive pulmonary disease (COPD) reveal a pH of 7.29 with a decreased PaO 2 and an elevated PaCO 2. Which initial treatment does the nurse expect the provider to most likely order? 1.) Intravenous fluids 2.) High-flow oxygen 3.) Sodium bicarbonate 4.) Bronchodilator therapy

4 This patient has signs of respiratory acidosis, so the first intervention is to improve ventilation. To accomplish this, bronchodilators are often used. Oxygen may be used but should be given cautiously to patients with COPD who may rely on hypoxia and not hypercarbia as a stimulus to breathe. Low-flow oxygen would be more appropriate. Intravenous fluids and sodium bicarbonate are used to treat metabolic acidosis.

Which increased blood arterial level causes a compensatory increase in respiration rate? 1.) pH 2.) Lactate 3.) Bicarbonate 4.) Carbon dioxide

4 When the amount of carbon dioxide in arterial blood rises, the central nervous system compensates for the imbalance by increasing the rate and depth of breathing. Increased respiration rate is not a response to rising lactate, pH, or bicarbonate.Test-Taking Tip: Attempt to select the answer that is most complete and includes the other answers within it. For example, a stem might read, "A child's intelligence is influenced by:" and three options might be genetic inheritance, environmental factors, and past experiences. The fourth option might be multiple factors, which is a more inclusive choice and therefore the correct answer.