16 ABGs

To evaluate the effectiveness of ordered interventions for a patient with ventilatory failure, which diagnostic test will be most useful to the nurse? Chest x-ray Oxygen saturation Arterial blood gas analysis Central venous pressure monitoring

ANS Oxygen saturation Arterial blood gas (ABG) analysis is most useful in this setting because ventilatory failure causes problems with CO2 retention, and ABGs provide information about the PaCO2 and pH. The other tests may also be done to help in assessing oxygenation or determining the cause of the patients ventilatory failure.

The laboratory has just called with the arterial blood gas (ABG) results on four patients. Which result is most important for the nurse to report immediately to the health care provider? pH 7.34, PaO2 82 mm Hg, PaCO2 40 mm Hg, and O2 sat 97% pH 7.35, PaO2 85 mm Hg, PaCO2 45 mm Hg, and O2 sat 95% pH 7.46, PaO2 90 mm Hg, PaCO2 32 mm Hg, and O2 sat 98% pH 7.31, PaO2 91 mm Hg, PaCO2 50 mm Hg, and O2 sat 96%

ANS pH 7.31, PaO2 91 mm Hg, PaCO2 50 mm Hg, and O2 sat 96% These ABGs indicate uncompensated respiratory acidosis and should be reported to the health care provider. The other values are normal or close to normal.

A patient in metabolic alkalosis is admitted to the emergency department, and pulse oximetry (SpO2) indicates that the O2 saturation is 94%. Which action should the nurse take next? Administer bicarbonate. Complete a head-to-toe assessment. Place the patient on high-flow oxygen. Obtain repeat arterial blood gases (ABGs).

ANS: Place the patient on high-flow oxygen. Although the O2 saturation is adequate, the left shift in the oxyhemoglobin dissociation curve will decrease the amount of oxygen delivered to tissues, so high oxygen concentrations should be given. Bicarbonate would worsen the patients condition. A head-to-toe assessment and repeat ABGs may be implemented. However, the priority intervention is to give high-flow oxygen.

Which finding by the nurse for a patient with a nursing diagnosis of impaired gas exchange will be most useful in evaluating the effectiveness of treatment? Even, unlabored respirations Pulse oximetry reading of 92% Respiratory rate of 18 breaths/minute Absence of wheezes, rhonchi, or crackles

ANS: Pulse oximetry reading of 92% For the nursing diagnosis of impaired gas exchange, the best data for evaluation are arterial blood gases (ABGs) or pulse oximetry. The other data may indicate either improvement or impending respiratory failure caused by fatigue.

The nurse analyzes the results of a patients arterial blood gases (ABGs). Which finding would require immediate action? The bicarbonate level (HCO3) is 31 mEq/L. The arterial oxygen saturation (SaO2) is 92%. The partial pressure of CO2 in arterial blood (PaCO2) is 31 mm Hg. The partial pressure of oxygen in arterial blood (PaO2) is 59 mm Hg.

ANS: The partial pressure of oxygen in arterial blood (PaO2) is 59 mm Hg. All the values are abnormal, but the low PaO2 indicates that the patient is at the point on the oxyhemoglobin dissociation curve where a small change in the PaO2 will cause a large drop in the O2 saturation and a decrease in tissue oxygenation. The nurse should intervene immediately to improve the patients oxygenation.

A patient who is lethargic and exhibits deep, rapid respirations has the following arterial blood gas (ABG) results: pH 7.32, PaO2 88 mm Hg, PaCO2 37 mm Hg, and HCO3 16 mEq/L. How should the nurse interpret these results? Metabolic acidosis Metabolic alkalosis Respiratory acidosis Respiratory alkalosis

ANS: metabolic acidosis The pH and HCO3 indicate that the patient has a metabolic acidosis. The ABGs are inconsistent with the other responses.

The ICU nurse is caring for a patient who experienced trauma in a workplace accident. The patient iscomplaining of having trouble breathing with abdominal pain. An ABG reveals the following results: pH7.28, PaCO2 50 mm Hg, HCO3 23 mEq/L. The nurse should recognize the likelihood of what acid-base disorder? A) Respiratory acidosis B) Metabolic alkalosis C) Respiratory alkalosis D) Mixed acidbase disorder

ANS: Mixed acid-base disorder Patients can simultaneously experience two or more independent acidbase disorders. A normal pH in thepresence of changes in the PaCO2 and plasma HCO3 concentration immediately suggests a mixeddisorder, making the other options incorrect.

A patient who is being treated for pneumonia starts complaining of sudden shortness of breath. Anarterial blood gas (ABG) is drawn. The ABG has the following values: pH 7.21, PaCO2 64 mm Hg,HCO3 = 24 mm Hg. What does the ABG reflect? A) Respiratory acidosis B) Metabolic alkalosis C) Respiratory alkalosis D) Metabolic acidosis

Ans: Respiratory acidosis Feedback: The pH is below 7.40, PaCO2 is greater than 40, and the HCO3 is normal; therefore, it is a respiratoryacidosis, and compensation by the kidneys has not begun, which indicates this was probably an acuteevent. The HCO3 of 24 is within the normal range so it is not metabolic alkalosis. The pH of 7.21indicates an acidosis, not alkalosis. The pH of 7.21 indicates it is an acidosis but the HCO3 of 24 iswithin the normal range, ruling out metabolic acidosis.