A patient with an oral endotracheal (ET) tube has tube feeding in progress. To address the risk for aspiration, the nurse will perform which intervention for this patient?

Choice A rationale

Systemic vascular resistance (SVR) specifically measures the resistance the left ventricle must overcome to eject blood into the systemic circulation. It does not directly cause an increase in pulmonary vascular resistance (PVR), which is the resistance in the lung's blood vessels. While severe left sided heart failure can eventually lead to pulmonary backup, an increase in SVR itself is a systemic afterload issue. Respiratory rate changes are usually secondary to compensatory mechanisms or distress rather than a direct hemodynamic effect.

Choice B rationale

An increase in systemic vascular resistance usually results in an increase in arterial blood pressure, as pressure is the product of flow and resistance. If resistance increases and the heart maintains its output, the pressure will rise. Mean arterial pressure (MAP) typically increases with higher SVR unless the heart's pumping ability fails significantly. Therefore, decreasing blood pressure is generally the opposite of what is expected when SVR increases, provided the cardiac compensatory mechanisms are still functioning effectively.

Choice C rationale

Increasing systemic vascular resistance represents increased afterload. According to the Frank Starling law and basic hemodynamics, as afterload increases, it becomes harder for the heart to pump blood out, which typically leads to a decrease in stroke volume and subsequently a decrease in cardiac output. It would be highly unusual for cardiac output to increase in response to higher resistance unless there was a massive increase in contractility or heart rate to compensate for the added pressure work.

Choice D rationale

Increased systemic vascular resistance raises the afterload on the left ventricle, forcing the myocardium to work harder to eject blood. This increased workload directly leads to higher myocardial oxygen demands. Simultaneously, the higher resistance often leads to a reduction in stroke volume and cardiac output because the ventricle cannot empty as efficiently against the high pressure. Normal SVR ranges from 800 to 1200 dynes/sec/cm-5. High SVR can lead to heart strain and decreased systemic perfusion.

Choice A rationale

Dilution can sometimes reduce the irritation of a drug on the vein wall, but it is not a universal solution for preventing chemical or physical incompatibilities between two different medications. If two drugs are chemically incompatible, mixing them in a syringe or intravenous line can still result in the formation of a precipitate or the degradation of the active ingredients, regardless of the amount of sterile water or saline added to the mixture.

Choice B rationale

Nurses have a professional and legal responsibility to ensure medication safety, which includes checking for drug-drug or drug-fluid incompatibilities. Administering medications that are known to be incompatible simply because they were ordered by a health care provider is a violation of safety protocols. Such an action could lead to therapeutic failure, the administration of toxic byproducts, or the injection of solid particles into the patient's bloodstream, causing severe harm.

Choice C rationale

Intravenous drug incompatibility refers to a reaction that occurs when two or more drugs are mixed, resulting in a physical or chemical change. Physical incompatibility often manifests as precipitation, cloudiness, or color changes, while chemical incompatibility involves a loss of potency or the creation of toxic compounds. These reactions can block intravenous lines or cause an embolism in the patient. Understanding this allows the nurse to use separate lines or flush thoroughly between medications.

Choice D rationale

While a nurse must address an incompatibility, the first step is usually to look for alternative administration methods, such as using a different IV site or flushing the line with a compatible fluid between doses. Requesting a completely different route of administration from the provider might eventually be necessary if no IV solution is possible, but it is not the definition of an incompatibility nor is it always the immediate or most appropriate clinical intervention required.