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Study Guide NURS 2140 Chapter 19 – Acid Base Review Practice Questions Interpreting Arterial Blood Gas Self Study: (condensed from the self study packet offered at Orlando Regional Healthcare, Education & Development, copyright 2004) “Arterial blood gas analysis is an essential part of diagnosing and managing a patient’s Oxygenation status and acid-base balance. The usefulness of this diagnostic tool is dependent on being able to correctly interpret the results. This self- learning packet will examine the components of an arterial blood gas, what each component represents and the interpretation of these values to determine the patient’s condition and treatment.” The Basics explained: The pH is a measurement of the acidity or alkalinity of the blood. It is inversely proportional to the number of hydrogen ions (H+) in the blood. The more H+ present, the lower the pH will be. Likewise, the fewer H+ present, the higher the pH will be. The pH of a solution is measured on a scale from 1 (very acidic) to 14 (very alkalotic). A liquid with a pH of 7, such as water, is neutral (neither acidic nor alkalotic). 1 7 14 Very Acidic Neutral Very Alkalotic (Base) 1

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Page 1: faculty.mccneb.edufaculty.mccneb.edu/tmchampion/ACID BASE SELF STUD…  · Web viewStudy Guide NURS 2140. Chapter 19 – Acid Base Review Practice Questions. Interpreting Arterial

Study Guide NURS 2140

Chapter 19 – Acid Base Review Practice Questions

Interpreting Arterial Blood Gas Self Study: (condensed from the self study packet offered at Orlando Regional Healthcare, Education & Development, copyright 2004)

“Arterial blood gas analysis is an essential part of diagnosing and managing a patient’sOxygenation status and acid-base balance. The usefulness of this diagnostic tool is dependenton being able to correctly interpret the results. This self-learning packet will examine thecomponents of an arterial blood gas, what each component represents and the interpretation ofthese values to determine the patient’s condition and treatment.”

The Basics explained:

The pH is a measurement of the acidity or alkalinity of the blood. It is inversely proportional tothe number of hydrogen ions (H+) in the blood. The more H+ present, the lower the pH will be.Likewise, the fewer H+ present, the higher the pH will be. The pH of a solution is measured ona scale from 1 (very acidic) to 14 (very alkalotic). A liquid with a pH of 7, such as water, isneutral (neither acidic nor alkalotic).

1 7 14 Very Acidic Neutral Very Alkalotic (Base)

The normal blood pH range is 7.35 to 7.45. In order for normal metabolism to take place, thebody must maintain this narrow range at all times. When the pH is below 7.35, the blood is saidto be acidic. Changes in body system functions that occur in an acidic state include a decreasein the force of cardiac contractions, a decrease in the vascular response to catecholamines, anda diminished response to the effects and actions of certain medications. When the pH is above7.45, the blood is said to be alkalotic. An alkalotic state interferes with tissue oxygenation andnormal neurological and muscular functioning. Significant changes in the blood pH above 7.8or below 6.8 will interfere with cellular functioning, and if uncorrected, will lead to death.

Key Concepts: The only 2 ways an acidotic state can exist is from either too much PaCO2 or too little HCO3. The only 2 ways an alkalotic state can exist is from either too little PaCO2 or too much HCO3.

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The body regulates acid base in order to maintain normal pH (7.35-7.45) by using delicate buffer mechanisms between the respiratory and renal systems.

The Respiratory (Lungs) Buffer ResponseA normal by-product of cellular metabolism is carbon dioxide (CO2). CO2 is carried in theblood to the lungs, where excess CO2 combines with water (H2O) to form carbonic acid(H2CO3). The blood pH will change according to the level of carbonic acid present. Thistriggers the lungs to either increase or decrease the rate and depth of ventilation until theappropriate amount of CO2 has been re-established. Activation of the lungs to compensate foran imbalance starts to occur within 1 to 3 minutes.

The Renal (Metabolic) Buffer ResponseIn an effort to maintain the pH of the blood within its normal range, the kidneys excrete orretain bicarbonate (HCO3-). As the blood pH decreases, the kidneys will compensate byretaining HCO3- and as the pH rises, the kidneys excrete HCO3- through the urine. Although thekidneys provide an excellent means of regulating acid-base balance, the system may take fromhours to days to correct the imbalance. When the respiratory and renal systems are workingtogether, they are able to keep the blood pH balanced by maintaining 1 part acid to 20 partsbase.

ACID BASE DISORDERS

Respiratory AcidosisRespiratory acidosis is defined as a pH less than 7.35 with a PaCO2 greater than 45 mm Hg.Acidosis is caused by an accumulation of CO2 which combines with water in the body toproduce carbonic acid, thus, lowering the pH of the blood. Any condition that results inhypoventilation can cause respiratory acidosis. These conditions include:

Central nervous system depression related to head injury Central nervous system depression related to medications such as narcotics, sedatives, or anesthesia Impaired respiratory muscle function related to spinal cord injury, neuromuscular diseases, or neuromuscular blocking drugs Pulmonary disorders such as atelectasis, pneumonia, pneumothorax, pulmonary edema, or bronchial obstruction Massive pulmonary embolus Hypoventilation due to pain, chest wall injury/deformity, or abdominal distension.

SIGNS AND SYMPTOMS OF RESPIRATORY ACIDOSISPulmonary Dyspnea

Respiratory distressShallow and/or slow respirations

Cardiovascular TachycardiaDysrhythmias

Neurological HeadacheRestlessnessConfusion

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CLINICAL APPLICATION:If the CO2 becomes extremely high, drowsiness and unresponsiveness may be noted.

Increasing ventilation (minute volume) will correct respiratory acidosis. The method for achieving this will vary with the cause of hypoventilation. If the patient is unstable, manual ventilation with a bag mask (ambu bag) is indicated until the underlying problem can be addressed. After stabilization, rapidly resolvable causes are addressed immediately. Causes that can be treated rapidly include pneumothorax, pain, and CNS depression related to medications (i.e.: narcotic overdose-narcan). If the cause cannot be readily resolved, the patient may require mechanical ventilation while treatment is rendered. Although patients with hypoventilation often require supplemental oxygen, it is important to remember that oxygen alone will not correct the problem.

Respiratory AlkalosisRespiratory alkalosis is defined as a pH greater than 7.45 with a PaCO2 less than 35 mm Hg.Any condition that causes hyperventilation can result in respiratory alkalosis. These conditionsinclude:

Psychological responses, such as anxiety or fear Pain Increased metabolic demands, such as fever, sepsis, pregnancy, or thyrotoxicosis (condition caused by overactive thyroid) Medications, such as respiratory stimulants Central nervous system lesions (abnormality in CNS caused by disease or trauma)

SIGNS AND SYMPTOMS OF RESPIRATORY ALKALOSISCardiovascular Dysrhythmias

PalpitationsDiaphoresis

Neurological Light-headednessNumbness and tinglingConfusionInability to concentrateBlurred vision

Miscellaneous Dry mouthTetanic spasms of the arms and legs

CLINICAL APPLICATION:Treatment of respiratory alkalosis centers on resolving the underlying problem.Patients presenting with respiratory alkalosis have dramatically increased work ofbreathing and must be monitored closely for respiratory muscle fatigue. When therespiratory muscles become exhausted, acute respiratory failure may ensue.

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Metabolic AcidosisMetabolic acidosis is defined as a bicarbonate level of less than 22 mEq/L with a pH of lessthan 7.35. Metabolic acidosis is caused by either a deficit of base in the bloodstream or anexcess of acids, other than CO2. Diarrhea and intestinal fistulas may cause decreased levels ofbase. Causes of increased acids include: Renal failure Diabetic ketoacidosis Anaerobic metabolism Starvation Salicylate (aspirin) intoxication

SIGNS AND SYMPTOMS OF METALBOLIC ACIDOSISPulmonary Kussmaul’s respirations (deep and labored breathing)Cardiovascular Dysrhythmias

Warm, flushed skinNeurological Headache

ConfusionRestlessnessLethargyStupor or coma

Gastrointestinal Nausea and vomiting

As with most acid-base imbalances, the treatment of metabolic acidosis is dependent upon thecause. The presence of metabolic acidosis should spur a search for hypoxic tissue somewherein the body. Hypoxemia can lead to anaerobic metabolism system-wide, but hypoxia of anytissue bed (brain, heart, kidneys, liver, pancreas, etc.) will produce metabolic acids as a result of anaerobic metabolism even if the PaO2 is normal. The only appropriate way to treat this source of acidosis is to restore tissue perfusion to the hypoxic tissues. Other causes of metabolic acidosis should be considered after the possibility of tissue hypoxia has been addressed.

CLINICAL APPLICATION:Current research has shown that the use of sodium bicarbonate is indicated only for knownbicarbonate-responsive acidosis, such as that seen with renal failure. Routine use of sodiumbicarbonate to treat metabolic acidosis results in subsequent metabolic alkalosis withhypernatremia and should be avoided.

Metabolic AlkalosisMetabolic alkalosis is defined as a bicarbonate level greater than 26 mEq/liter with a pH greater

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than 7.45. Either an excess of base or a loss of acid within the body can cause metabolicalkalosis. Excess base occurs from

ingestion of antacids excessive use of bicarbonate use of lactate in dialysis vomiting gastric suction hypochloremia (low chloride) excess administration of diuretics high levels of aldosterone

SIGNS AND SYMPTOMS OF METALBOLIC ALKALOSISPulmonary Respiratory depressionMusculoskeletal Weakness

Muscle twitchingMuscle crampsTetany

Neurological DizzinessLethargyDisorientationSeizuresComa

Gastrointestinal Nausea Vomiting

Metabolic alkalosis is one of the most difficult acid-base imbalances to treat. Bicarbonateexcretion through the kidneys can be stimulated with drugs such as acetazolamide (Diamox®),but resolution of the imbalance will be slow. In severe cases, IV administration of acids maybe used.

CLINICAL APPLICATION:It is significant to note that metabolic alkalosis in hospitalized patients is usuallyiatrogenic (brought on about unintentionally by treatment of other medical conditions).

COMPONENTS OF THE ARTERIAL BLOOD GAS

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The arterial blood gas provides the following values:

pH:Measurement of acidity or alkalinity, based on the hydrogen (H+) ions present.The normal range is 7.35 to 7.45Remember:pH > 7.45 = alkalosispH< 7.35 = acidosis

PaO2:

The partial pressure of oxygen that is dissolved in arterial blood.The normal range is 80 to 100 mm Hg.

SaO2:

The arterial oxygen saturation.The normal range is 95% to 100%.

PaCO2:

The amount of carbon dioxide dissolved in arterial blood.The normal range is 35 to 45 mm Hg.Remember:pCO2 >45 = acidosispCO2 <35 = alkalosis

HCO3

The calculated value of the amount of bicarbonate in the bloodstream.The normal range is 22 to 26 mEq/literRemember:HCO3 > 26 = alkalosis HCO3 < 22 = acidosis

B.E.The base excess indicates the amount of excess or insufficient level of bicarbonate in thesystem.The normal range is -2 to +2 mEq/liter. (-3 to +3 in Osborn book)Remember:A negative base excess indicates a base deficit in the blood.

THE 6 EASY STEPS TO ARTERIAL BLOOD GAS (ABG) INTREPRETATION: (condensed from www.ED4NURSES.com, copyright 1997-2012, ED4Nurses, Inc.)

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The 6 Easy Steps to ABGAnalysis:

Step 1: Analyze the pHThe first step in analyzing ABGs is to look at the pH. Normal blood pH is7.4, plus or minus 0.05, forming the range 7.35 to 7.45. If blood pH falls below 7.35 it is acidic. If blood pH rises above 7.45, it is alkalotic. If it falls into the normal range, note what side of 7.4 it falls on. Lower than 7.4 is normal/acidic, higher than 7.4 is normal/alkalotic.

Step2: Analyze the CO2The second step is to examine the pCO2. Normal pCO2 levels are 35 ‐ 45mmHg. Below 35 is alkalotic, above 45 is acidic.

Step 3: Analyze the HCO3The third step is to look at the HCO3 level. A normal HCO3 level is 22--‐26 mEq/L. If the HCO3 is below 22, the patient is acidotic. If the HCO3 is above 26, the patient is alkalotic.

Step 4: Match the CO2 or the HCO3 with the pHNext match either the pCO2 or the HCO3 with the pH to determine the acid--‐base disorder. For example, if the pH is acidotic, and the CO2 is acidotic, then the acid--‐base disturbance is being caused by the respiratory system. Therefore, we call it a respiratory acidosis. However, if the pH is alkalotic and the HCO3 is alkalotic, the acid--‐base disturbance is being caused by the metabolic (or renal) system. Therefore, it will be a metabolic alkalosis.

Step 5: Does the CO2 or HCO3 go the opposite direction of the pH?Fifth, does either the CO2 or HCO3 go in the opposite direction of the pH? If so, there is compensation by that system. For example, the pH is acidotic, the CO2 is acidotic, and the HCO3 is alkalotic. The CO2 matches the pH making the primary acid--‐base disorder respiratory acidosis. The HCO3 is opposite of the pH and would be evidence of compensation from the metabolic system. (explained more in next section).

Step 6: Analyze the pO2 and the O2 saturation.Finally, evaluate the PaO2 and O2 sat. If they are below normal there is evidence of hypoxemia.

ABG Test Normal Range Decreased Value Increased Value

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pH 7.35 – 7.45 Acidosis AlkalosisPaCO2 34 – 45 Alkalosis AcidosisHCO3 22-26 Acidosis AlkalosisPaO2 (dissolved O2) 80-100 Hypoxemia O2 TherapySaO2 (saturation) 95-100% Hypoxemia ----------------------

Notice that if the pH is lower than 7.35 it indicates acidosis, if the pH is higher than 7.45 it indicates alkalosis. The HCO3 is also acidotic if it is low: less than 22 indicate acidosis. If the HCO3 is higher than 26 it indicates alkalosis. However, if the CO2 is lower than 35 it indicates alkalosis, and if the CO2 is higher than 45 It indicates acidosis. One way to remember this relationship is to use the acronym. ROME.

RespiratoryOppositeMetabolicEqual

The PaCO2 is the respiratory component of the ABG, and if it is low and the pH is high the patient would have a respiratory alkalosis. They move in opposite directions to match.The HCO3 is the metabolic component of the ABG. If the HCO3 is low and the pH is low the patient would have metabolic acidosis. They move in the same direction to match.

STEP 5 REFERS TO COMPENSATION.Compensation is the attempt by the body to maintain homeostasis by correcting the pH. The opposite system will do this. The component of the respiratory system that balances the pH is the dissolved carbon dioxide (PaCO2) that is produced by the cellular processes and removed by the lungs. The component of the renal system that balances the pH is the dissolved bicarbonate (HCO3) produced by the kidneys. The kidneys also help control pH by eliminating hydrogen (H+) ions. The way the two systems interact is through the formation of carbonic acid (H2CO3).Movement through the carbonic acid system is fluid and constant. What this means is that water (H2O) can combine with CO2 and form carbonic acid. If necessary, carbonic acid (H2CO3) can then break up to form hydrogen ions (H+) and bicarbonate (HCO3). This system works in both directions. By balancing back and forth, a normal pH is achieved. The respiratory system balances the pH by increasing or decreasing the respiratory rate, thereby manipulating the PaCO2 level. Fast and deep breathing (Increased minute volume) “blows off” PaCO2. Conversely, slow and shallow breathing (decreased minute volume) “retains” PaCO2. The renal system balances pH by producing HCO3 or by eliminating hydrogen ions (H+). The renal system will reflect changes in metabolic activity within the body. For example, a patient in shock will undergo anaerobic metabolism, which produces lactic acid. The production of lactic acid will bind or use up available HCO3 and will be manifested by a decrease in the HCO3 level. Therefore, the HCO3 level is an indicator of metabolic acid-base balance.

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Balance must always be achieved by the opposing system. Therefore, our body regulates pH by using the opposing system to balance pH. So if the pH is out of balance because of a respiratory disorder, it will be the renal system that makes the corrections to balance the pH. Conversely, if the renal system is to blame for the pH disorder, the respiratory system will have to compensate. This process is called compensation. Compensation may not always be complete.Complete or Full compensation returns the pH balance to normal. There are times when the imbalance is too large for compensation to restore the pH to normal. This is called partial compensation. Like the seesaw, compensation must come from the opposite system.

Step 5 analyzes compensation by looking for the system that is going the opposite direction of the pH. Opposite in terms of acidosis and alkalosis. (i.e.: pH is acid (low), HCO3 is acid (low) but PaCO2 is alkalotic (high) – would be Metabolic Acidosis with partial compensation from the respiratory system).

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Examples of interpretation ABG are using the six steps:

Example 1:

Step 1: The pH is less than 7.35, so it is acidotic.

Step 2: The CO2 is greater than 45, so it is acidotic.

Step 3: The HCO3 is normal.

Step 4: The PaCO2 matches the pH, because they are both acidotic. Therefore the imbalance is respiratory acidosis. It is acidotic because the pH is acidotic, it is respiratory because the PaCO2 moved opposite (ROME) and matches the pH.

Step 5: The HCO3 is normal, therefore no compensation. If the HCO3 was alkalotic (high) (moved in opposite direction to pH) then a compensation (partial) would be present.

Step 6: Lastly, the PaO2 and SaO2 are both low indicating hypoxemia.

The Full Interpretation for this ABG is: Uncompensated Respiratory Acidosis with hypoxemia.

This patient has an acute respiratory disorder. Caused by hypoventilation. Retaining CO2. Hypoventilation is slow shallow breathing (decreased Minute Volume) and decreased Alveolar Minute Volume (areas that actually participate in gas exchange in the lungs). These conditions are: COPD, Drug overdoses (narcotics, opiates), obstructed airway, neuromuscular diseases that affect breathing, chest trauma, high spinal column injuries and pulmonary edema.

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pH 7.27 acidotic

PaCO2 53 acidotic

PaO2 50 low

SaO2 79% low

HCO3 24 normal

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Example 2:

Step 1: The pH is greater than 7.45, so it is alkalotic

Step 2: The PaCO2 is less than 35, so it is alkalotic.

Step 3: The HCO3 is normal.

Step 4: The PaCO2 matches the pH, because they are both alkalotic. Therefore the imbalance is respiratory alkalosis. It is alkalotic because the pH is alkalotic; it is respiratory because the PaCO2 moved opposite (ROME) and matches the pH.

Step 5: The HCO3 is normal, therefore there is no compensation. If the HCO3 was acidotic (low) (opposite of the pH) then compensation (partial) would be present.

Step 6: Lastly, the PaO2 and SaO2 are normal indicating normal oxygenation (no hypoxemia).

The Full Interpretation for this ABG is: Uncompensated respiratory alkalosis.

This patient is hyperventilating. “Blowing off CO2”. Hyperventilation is fast and deep breathing (increased Minute Volume) and increased Alveolar Minute Volume (areas that actually participate in gas exchange in the lungs). Conditions that can cause this are: Anxiety, Pain, High Altitudes, Fever, initial stages of Pulmonary embolism, hypoxia. Treatment for this patient would be to treat the condition: anxiety medications, pain medications, fever reducers, etc.), encourage patient to breath slow, possible rebreathing in paper bag to restore CO2.

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pH 7.52 alkalotic

PaCO2 29 alkalotic

PaO2 100 normal

SaO2 98% normal

HCO3 23 normal

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Example 3:

Step 1: The pH is less than 7.35, so it is acidotic.

Step 2: The PaCO2 is Normal.

Step 3: The HCO3 is less than 22, so it is acidotic.

Step 4: The HCO3 matches the pH, because they are both acidotic. Therefore the imbalance is metabolic acidosis. It is acidotic because the pH is acidotic; it is metabolic because the HCO3 matches the pH.

Step 5: The PaCO2 is normal, therefore, no compensation.

Step 6: Lastly, the PaO2 and SaO2 are normal indicating normal oxygenation (no hypoxemia)

The full interpretation of this ABG is: Uncompensated Metabolic acidosis.

The patient has an acute metabolic disorder such as Diabetic Ketoacidosis (DKA), severe starvation, Salisylate (Aspirin) Overdose, Shock, Sepsis, severe diarrhea, renal failure. Treatment is to treat the underlying disorder, administer medication and fluids, replace electrolytes, and dialysis.

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pH 7.18 acidotic

PaCO2 44 normal

PaO2 92 normal

SaO2 95% normal

HCO3 16 acidotic

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Example 4.

Step 1: The pH is less than 7.35, so it is acidotic

Step 2: The PaCO2 is less than 35, so it is alkalotic.

Step 3: The HCO3 is less than 22, so it is acidotic.

Step 4: The HCO3 matches the pH, because both are acidotic. Therefore the imbalance is a metabolic acidosis. It is acidotic because the pH is acidotic; it is metabolic because the HCO3 matches the pH.

Step 5: The PaCO2 is alkalotic and goes the opposite direction of the pH, so therefore there is compensation. Because the pH is not in the normal range (7.35 – 7.45) the compensation is called partial.

Step 6: Lastly, the PaO2 and the SaO2 are low indicating hypoxemia. (inadequate oxygenation).

The full interpretation for this ABG is: Partially-compensated metabolic acidosis with hypoxemia.

There are a number of conditions that can cause metabolic acidosis: renal failure, severe diarrhea, Aspirin overdose, DKA, Shock, and Sepsis. This patient is probably in shock because the metabolic acidosis is associated with poor oxygenation.

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pH 7.30 acidotic

PaCO2 30 alkalotic

PaO2 68 low

SaO2 92% low

HCO3 14 acidotic

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Example 5:

Step 1: The pH is greater than 7.45, so it is alkalotic.

Step 2: The PaCO2 is greater than 45, so it is acidotic.

Step 3: The HCO3 is greater than 26, so it is alkalotic.

Step 4: The HCO3 matches the pH, because both are alkalotic. Therefore the imbalance is a metabolic alkalosis. It is alkalotic because the pH is alkalotic; it is metabolic because the HCO3 matches the pH.

Step 5: The PaCO2 is acidotic and goes the opposite direction of the pH, so therefore there is compensation. Because the pH is not in the normal range (7.35 – 7.45) the compensation is called partial.

Step 6: Lastly, the PaO2 and the SaO2 are normal indicating normal oxygenation (no hypoxemia).

The full interpretation for this ABG is: Partially-compensated metabolic alkalosis.

The patient is probably losing stomach acid from vomiting, NG tube drainage/suctioning, use of anti-acids or medications that reduce stomach acid, or potassium wasting diuretics (thiazides like furosemide (Lasix).

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pH 7.60 alkalotic

PaCO2 56 acidotic

PaO2 92 normal

SaO2 98% normal

HCO3 35 alkalotic

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Example 6: (last one) (Full compensation – ohh shit! Now I am confused again!)

Step 1: The pH is normal but less than 7.40, so it is within range but on the acidotic (low) side of the normal range.

Step 2: The CO2 is greater than 45, so it is acidotic.

Step 3: The HCO3 is greater than 26 so it is alkalotic.

Step 4: The PaCO2 matches the pH, only because the normal pH is on the low side of the range <7.40 (towards acidosis). So the primary imbalance is respiratory.

Step 5: The HCO3 is alkalotic and is going in the opposite direction of the normal pH; therefore compensation is present from the renal system. The pH is between 7.35 and 7.40 (low normal), so it is fully compensated. Therefore the imbalance is respiratory acidosis with full compensation.

Step 6: Lastly, the PaO2 and SaO2 are both low indicating hypoxemia.

The Full Interpretation for this ABG is: Fully Compensated Respiratory Acidosis.

Notice that the only difference between partially and fully compensated states is whether or not the pH has returned to within the normal range. In compensated acid-base disorders, the pH will frequently fall either on the low or high side of neutral (7.40). Making note of where the pH falls within the normal range is helpful in determining if the original acid-base disorder was acidosis or alkalosis.

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pH 7.38 normal

PaCO2 62 acidotic

PaO2 93 normal

SaO2 97% normal

HCO3 35 alkalotic

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Now test yourself: answer the questions

ABG Interpretation Review and Application:

Question 1:

A patient’s blood pH is decreasing. The nurse realizes that this patient’s hydrogen ion concentration is:

1. Increasing

2. Decreasing

3. Being affected by oxygen concentration

4. Stabilizing

Question 2:

A patient is admitted with the diagnosis of diabetic ketoacidosis. The nurse realizes that this patient’s body will attempt to attain acid-base balance by:

1. Decreasing its respiratory rate.

2. Increasing the reabsorption of hydrogen ions.

3. Increasing the secretion of hydrogen ions.

4. Decreasing the reabsorption of bicarbonate.

Question 3: A patient has a respiratory rate of 20. The nurse calculates this patient’s minute ventilation to be:

1. 1 L/min

2. 2 L/min

3. 5 L/min

4. 10 L/min

Question 4:

The nurse, admitting a patient with diabetes, believes the patient is attempting to correct an acidotic condition. Which of the following did this nurse most likely observe while assessing this patient?

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1. Slow methodical respirations

2. Deep rapid respirations

3. Change in level of consciousness

4. Intact extraocular movements

Question 5:

The nurse is caring for a patient with metabolic acidosis. The nurse realizes that which of the following laboratory values might be altered for this patient?

1. Ammonia

2. Blood-urea-nitrogen

3. Creatinine

4. Prothrombin

Question 6:

The nurse is reviewing a patient’s arterial blood gas results. Which of the following values should the nurse study first?

1. PaCO2

2. HCO3

3. Compensation

4. pH

Question 7:

The nurse is caring for a patient with pneumonia who has arterial blood gas values of: pH 7.20, PaCO2 75, HCO3

- 26, PaO2 44. Which of the following would be a priority for this patient?

1. Assisting the patient to breathe into a paper bag.

2. Preparing to administer Sodium Bicarbonate IV.

3. Placement of the patient in high Fowler’s position.

4. Administration of the prn sedative available.

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Question 8:

A patient is admitted in respiratory acidosis secondary to barbiturate overdose. Which of the following will the nurse most likely assess in this patient?

1. Kussmaul’s respirations

2. Seizures

3. Slow, shallow respirations

4. Increased deep tendon reflexes

Question 9: The nurse is providing discharge instructions to a patient with respiratory alkalosis. Which of the following statements indicates the patient understands the instructions?

1. “I will not take my Lasix without a potassium supplement.”

2. “I will not use Mylanta 5-6 times a day like I used to.”

3. “I will take a stress management class or seek counseling.”

4. “I will call my MD the next time I have diarrhea for a few days.”

Question 10:

A patient ABG’s come back as: pH: 7.33; PaCo2: 60; HCO3: 34, PaO2: 88; SaO2: 90%.

1. Uncompensated Respiratory Acidosis with hypoxemia.2. Partially-compensated respiratory alkalosis with normal oxygenation.3. Partially-compensated respiratory acidosis with hypoxemia.4. Respiratory acidosis with full compensation and with hypoxemia.

Question 11:

Interpret the following ABG’s: pH: 7.48; PaCO2: 42; HCO3: 30; PaO2: 94; SaO2:100%.

1. Metabolic acidosis without compensation.2. Respiratory alkalosis with partial compensation.3. Respiratory alkalosis without compensation.4. Metabolic alkalosis without compensation.

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Question 12:

In question 11, what is the oxygenation status?

1. Normal oxygenation2. Hypoxemia

Question 13:

Interpret the following ABG’s: pH: 7.38; PaCO2: 38; HCO3: 24; PaO2: 96; SaO2:98%.

1. Respiratory Alkalosis2. Normal ABG’s3. Metabolic Alkalosis4. None of the above

Question 14:

Interpret the following ABG’s: pH: 7.21; PaCO2: 60; HCO3: 24; PaO2: 66; SaO2:88%.

1. Normal ABG’s2. Uncompensated Respiratory Acidosis with hypoxemia.3. Partially-Compensated Metabolic Acidosis with hypoxemia.4. Fully-compensated Respiratory Acidosis and normal oxygenation.

Question 15:

Interpret the following ABG results: pH: 7.42; PaCO2: 58; HCO3: 31.

1. Partially-compensated metabolic acidosis.2. Fully compensated metabolic alkalosis.3. Uncompensated metabolic alkalosis.4. Fully compensated respiratory acidosis.

Question 16:

Interpret the following ABG results: pH: 7.36; PaCO2: 29; HCO3: 19.

1. Fully compensated respiratory acidosis2. Fully compensated respiratory alkalosis3. Fully compensated metabolic acidosis4. Fully compensated metabolic alkalosis

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