A client is admitted to the hospital with an acid base imbalance. Arterial blood gas (ABG) results are: Ph 7.33 (7.35-7.45), PaCO2 49mmHg (35-45mmHg), HCO3 26mEq/L (22-26mEq/L). How should the nurse interpret these results?

a. Metabolic alkalosis: Metabolic alkalosis can occur due to loss of gastric acid through suctioning of gastric contents via the nasogastric tube. Continuous suctioning of gastric contents can lead to loss of hydrogen ions (H+) and chloride ions (Cl-) from the stomach, resulting in metabolic alkalosis.

b. Metabolic acidosis: Metabolic acidosis is less likely in this scenario unless there are other factors contributing to acidosis, such as renal dysfunction or excessive administration of certain medications. Suctioning of gastric contents would lead to loss of acid, which could potentially predispose the client to metabolic alkalosis rather than metabolic acidosis.

c. Respiratory alkalosis: Respiratory alkalosis is less likely to occur in this scenario. Although the client is NPO and may be experiencing some respiratory compensation due to metabolic alkalosis, the primary acid-base disturbance would be metabolic rather than respiratory.

d. Respiratory acidosis: Respiratory acidosis is not typically associated with suctioning of gastric contents. Instead, it occurs due to inadequate alveolar ventilation, leading to retention of carbon dioxide (CO2) and subsequent respiratory acidosis. This imbalance is more commonly seen in conditions such as respiratory depression, neuromuscular disorders, or airway obstruction.

a. Dopamine: Dopamine is a medication that primarily acts as a vasopressor and inotropic agent. While it can increase cardiac contractility and improve cardiac output, it does not directly decrease afterload. In fact, dopamine may increase systemic vascular resistance (afterload) at higher doses.

b. Warfarin: Warfarin is an anticoagulant medication used to prevent blood clot formation, particularly in individuals with certain cardiac conditions such as atrial fibrillation or mechanical heart valves. While warfarin is important for preventing thromboembolic events in individuals with mitral valve regurgitation, it does not directly affect afterload.

c. Digoxin: Digoxin is a medication that primarily acts as a positive inotropic agent by increasing myocardial contractility. While it can improve cardiac function, particularly in individuals with heart failure, it does not directly decrease afterload.

d. Lisinopril: Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor medication that reduces blood pressure by inhibiting the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. By reducing angiotensin II levels, lisinopril dilates blood vessels and decreases systemic vascular resistance (afterload), thus reducing the workload on the heart. Therefore, lisinopril is the medication that would help decrease afterload for a client with mitral valve regurgitation.