7.3 Clinical Reasoning and Decision-Making Related to Cardiac Medications V2

Assessment and Cues

For just about every health condition, perfusion is assessed. Prior to giving any cardiac med, you need a baseline. This will always start with assessing heart rate (rate, rhythm) and blood pressure. For many conditions, you will also want to know capillary refill, skin temperature, skin colour, presence of peripheral edema and heart sounds (S1 S2). As the respiratory function is very much interrelated with the cardiovascular system, assessing respiratory function will also be done. At a minimum, respiratory rate, quality of respirations (depth, work of breathing), oxygen saturations, and chest auscultation.

Mechanism of action of meds are important to know

Understanding the mechanism of action of a cardiac medication will help a nurse choose the proper assessments to perform on a client. It will also help with understanding therapeutic effects and any adverse effects.  It is important for a nurse to complete a full cardiac assessment to fully understand the health status of the client, the safe implementation of the medication, and the expected effectiveness of the medication.

Many cardiovascular drugs alter a client’s blood pressure or heart rate, such as antiarrhythmics, cardiac glycosides, antihypertensives, and diuretics. As mentioned above, it is important for a nurse to assess a client’s blood pressure and heart rate prior to administration. For some meds, ECG monitoring may be ordered before a dose, periodically to assess for changes, or continuous monitoring.  Medication parameters are often included in the order by a healthcare provider.

Monitoring Labs

Electrolytes can play a large role in cardiac conduction and muscle function. Medications that alter electrolytes, such as Loop diuretics, require a review of laboratory values before administration. Loop diuretics such as furosemide (Lasix) often cause a depletion of potassium. If a nurse administers a loop diuretic to a client who already has low serum potassium levels (called hypokalemia), worsening symptoms of hypokalemia will occur, which can cause life-threatening arrhythmia.

Monitoring kidney function is also important when administering many cardiovascular medications. For example, diuretics can cause renal injury. A nurse should be aware of cardiovascular medications that are affected by impaired renal function or cause renal injury. In addition, a nurse must appropriately assess and report abnormal laboratory values such as worsening serum creatinine and glomerular filtration rates (GFR). It is also important to assess for signs of dehydration, as well as intake and output in client’s taking diuretics.

Anticoagulant medications cause serious risk for bleeding that can be life threatening. Prior to administering medication that alters a client’s coagulation, it is important to assess for signs and symptoms of unusual bleeding or bruising. Laboratory values, such as International Normalized Ratio (INR), PTT, or platelets, may also require review prior to administering an anticoagulant medication. Any new abnormal lab values or signs of increased bleeding and internal bleeding should be immediately reported.

Implementation

Before administration of any cardiovascular drug, it is vital for the nurse to determine if this cardiac medication is safe for this client at this time. For example, if the client’s heart rate or blood pressure is below the anticipated parameters, the medication should be withheld and the prescribing provider notified.

It is also important to consider the effect of the medication before administering it at the ordered time. For example, if a diuretic is prescribed before a client is sent to a diagnostic test, the test may be disrupted by the need for the client to urinate, and the dosage should be rescheduled for a later time. A more significant safety concern arises when a client who is scheduled for surgery is prescribed aspirin or an anticoagulant. The nurse should consider these types of upcoming events before administering medications as they are ordered.

Evaluation

Therapeutic response achieved?

It is always important to evaluate the client’s response to a medication compared to what is expected. Many medications require dose adjustments to produce desired effect. For example, IV heparin is administered based on a protocol that requires dose adjustment based on PTT or aPTT lab results to achieve therapeutic range (and avoid overdosage that can cause life-threatening bleeding).  Also, assess for any adverse effects that may have occurred, such as nausea or dizziness, both common effects from cardiac drugs.

Monitoring:

For all cardiac meds, monitor a client’s blood pressure, heart rate, intake and output, edema, or other cardiac assessments to evaluate if the ordered cardiac agents are effective or if further treatment or dosage adjustment is required.

Continually monitor the client for potential adverse effects of the medication. For example, is the client becoming dehydrated following the diuretic furosemide?  Are they developing muscle cramps and tingling in their feet, both signs of hypokalemia from diuresis? Is there labs that should be done to ensure the client is within normal limits, for example ordering electrolytes? Some adverse effects can be life threatening and require prompt notification to the prescribing provider.

Client teaching

Does the client understand the purpose of the medications?  Assess for basic understanding of what the drug does or is used for, for example, “this med will lower my blood pressure.” Make sure they know how to take the med correctly (with or without food, morning or bedtime), as well as common side effects.  Lastly, they should know when to return for follow up appointments, and when to notify their provider of changing symptoms.  Additional client education before discharge home is always required, especially if new medications are prescribed.