Question

The client is admitted with chronic obstructive pulmonary disease. The client's laboratory values reveal a \(\mathrm{CO}_2\) level of \(49 \mathrm{mEq} / \mathrm{L}\). The \(\mathrm{HCO}_3\) level is \(26 \mathrm{mEq} / \mathrm{L}\), and the \(\mathrm{pH}\) is \(7.32\). The nurse is aware that these laboratory values reveal: A. Metabolic acidosis B. Metabolic alkalosis C. Respiratory alkalosis D. Respiratory acidosis

Short answer

Answer: D. Respiratory acidosis

Step-by-step solution

Identify the normal reference ranges for the given values

The normal reference ranges for the given values are as follows: - Normal \(\mathrm{CO}_2\) level: \(35\) to \(45 \mathrm{mEq} / \mathrm{L}\) - Normal \(\mathrm{HCO}_3\) level: \(22\) to \(26 \mathrm{mEq} / \mathrm{L}\) - Normal \(\mathrm{pH}\) level: \(7.35\) to \(7.45\)

Compare the patient's values with the normal reference ranges

In this step, we will compare the patient's laboratory values to the normal reference ranges: - \(\mathrm{CO}_2\) level: \(49 \mathrm{mEq} / \mathrm{L}\) (higher than the normal range) - \(\mathrm{HCO}_3\) level: \(26 \mathrm{mEq} / \mathrm{L}\) (within the normal range) - \(\mathrm{pH}\) level: \(7.32\) (lower than the normal range)

Identify the type of acid-base imbalance

Based on the comparison made in Step 2, we can now identify the type of acid-base imbalance: - The high \(\mathrm{CO}_2\) level indicates a respiratory issue, as \(\mathrm{CO}_2\) is a respiratory variable. - The normal \(\mathrm{HCO}_3\) level suggests that there is no significant metabolic issue. - The low \(\mathrm{pH}\) level indicates acidosis, as it is below the normal range. Putting these findings together, we can conclude that the patient is experiencing Respiratory Acidosis.

Choose the correct answer

By analyzing the laboratory values and identifying the type of acid-base imbalance, we can conclude that the correct answer is: D. Respiratory acidosis

Key concepts

Respiratory Acidosis

Respiratory acidosis is a condition that arises when the lungs cannot effectively remove all the carbon dioxide (CO₂) produced by the body, leading to an excessive buildup of CO₂ in the bloodstream. This results in the blood becoming too acidic, a condition known as acidosis.

Under normal circumstances, the lungs regulate the levels of CO₂, a waste product of metabolism, by expelling it during exhalation. However, in cases of respiratory dysfunction, such as in patients with chronic obstructive pulmonary disease (COPD), the elimination of CO₂ is hampered. The retention of CO₂ causes an increase in the concentration of hydrogen ions, lowering the pH of the blood and causing the blood to become more acidic.

Common symptoms of respiratory acidosis include confusion, lethargy, and shortness of breath. The body may compensate for this acid-base imbalance over time by adjusting the kidney's retention and excretion of acids and bases, specifically bicarbonate ions (HCO₃). However, these compensatory mechanisms have limitations and can be overwhelmed, necessitating medical intervention to correct the underlying respiratory issue.

Acid-Base Imbalance

Acid-base imbalance occurs when the body's pH, which is normally tightly regulated, deviates from its normal range of 7.35 to 7.45. These disturbances are classified into four primary categories: metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis.

The acid-base status of an individual is determined by evaluating the pH, partial pressure of carbon dioxide (PaCO₂), and bicarbonate (HCO₃) concentrations in arterial blood. These parameters are interrelated; disturbances in PaCO₂ affect respiratory processes, while changes in HCO₃ concentration are usually a result of metabolic processes.

Metabolic acidosis is characterized by a low pH and low HCO₃, while metabolic alkalosis involves a high pH and high HCO₃. Respiratory acidosis and alkalosis are distinguished primarily by PaCO₂ levels, with respiratory acidosis reflecting high PaCO₂ and respiratory alkalosis indicative of low PaCO₂. Prompt and accurate diagnosis of these conditions is crucial as they can be life-threatening if not properly managed.

Nursing Laboratory Values Interpretation

Nursing laboratory values interpretation is a critical skill for healthcare providers, especially nurses who are often the first to review test results. The interpretation of these values assists in diagnosing conditions, monitoring patient progress, and evaluating the effectiveness of interventions.

In the context of respiratory acidosis, nurses must primarily interpret three key laboratory values: the CO₂ level, the HCO₃ level, and the pH. The normal ranges for these values in the blood are a CO₂ level of 35 to 45 mEq/L, an HCO₃ level of 22 to 26 mEq/L, and a pH level of 7.35 to 7.45.

When interpreting these results, nurses will compare the patient’s values against the established reference ranges. A higher than normal CO₂ level suggests respiratory acidosis, while HCO₃ levels indicate whether a metabolic issue is present. The pH reveals the overall acid-base status. In addition to understanding these numbers, nurses need to be aware of the patient’s clinical presentation and any underlying conditions that could contribute to abnormal lab results. Ultimately, the accurate interpretation of laboratory values is essential for providing high-quality patient care, guiding treatment decisions, and ensuring patient safety.