On arrival at the intensive care unit, a critically ill patient suffers respiratory arrest and is placed on mechanical ventilation. The physician orders pulse oximetry to monitor the patient’s arterial oxygen saturation (SaO₂) noninvasively. Which vital sign abnormality may alter pulse oximetry values?
Tachycardia
Hypotension
Tachypnea
Fever
The Correct Answer is B
Choice A: Tachycardia
Tachycardia, defined as a heart rate exceeding 100 beats per minute, can affect the accuracy of pulse oximetry readings. When the heart beats too quickly, it may not fill with enough blood between beats, leading to reduced perfusion and oxygen delivery to tissues. However, while tachycardia can influence the readings, it is not the most significant factor compared to hypotension.
Choice B: Hypotension
Hypotension, or low blood pressure, significantly impacts pulse oximetry accuracy. When blood pressure is low, there is reduced perfusion to peripheral tissues, including the extremities where pulse oximeters are typically placed. This reduced perfusion can lead to inaccurate readings, as the device may not detect sufficient blood flow to measure oxygen saturation accurately. Hypotension is a critical factor that can alter pulse oximetry values, making it the most relevant choice.
Choice C: Tachypnea
Tachypnea, or rapid breathing, can affect oxygen levels in the blood but does not directly interfere with the pulse oximeter’s ability to measure oxygen saturation. While it indicates respiratory distress and can lead to hypoxemia, the pulse oximeter can still provide accurate readings unless accompanied by other factors like low perfusion.
Choice D: Fever
Fever can cause peripheral vasodilation, which might theoretically affect pulse oximetry readings by altering blood flow to the extremities. However, this effect is generally minimal compared to the impact of hypotension. Fever alone is unlikely to cause significant inaccuracies in pulse oximetry measurements.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is ["A"]
Explanation
Choice A: Monitor for hypernatremia.
Hypernatremia, or high sodium levels in the blood, is a common complication of diabetes insipidus due to excessive water loss and insufficient water intake. Monitoring for hypernatremia involves regular blood tests to check sodium levels. Symptoms of hypernatremia include extreme thirst, confusion, muscle twitching, and seizures. Early detection and management are crucial to prevent severe complications.
Choice B: Monitor neuro status.
Monitoring neurological status is essential in patients with diabetes insipidus because severe hypernatremia can lead to neurological symptoms such as confusion, irritability, seizures, and even coma. Regular assessments of mental status, level of consciousness, and neurological function help in early detection of complications and timely intervention.
Choice C: Monitor for hyponatremia.
While hyponatremia (low sodium levels) is less common in diabetes insipidus, it can occur if there is excessive water intake without adequate sodium replacement. Symptoms include headache, nausea, vomiting, confusion, and seizures. Monitoring sodium levels helps in maintaining a balance and preventing complications.
Choice D: Monitor urine specific gravity.
Urine specific gravity measures the concentration of solutes in the urine. In diabetes insipidus, urine is typically very dilute, with a specific gravity of less than 1.005. Regular monitoring helps in assessing the effectiveness of treatment and the patient’s hydration status. It also aids in differentiating diabetes insipidus from other conditions with similar symptoms.
Choice E: Monitor strict I&O.
Strict monitoring of intake and output (I&O) is crucial in managing diabetes insipidus. This involves accurately measuring all fluids consumed and excreted to ensure proper hydration and electrolyte balance. It helps in identifying trends in fluid loss and guiding appropriate fluid replacement therapy.
Correct Answer is D
Explanation
Choice A: Rosebud-like Stoma Orifice
A rosebud-like stoma orifice is typically a normal appearance for a new stoma. The stoma should be moist, pink to red in color, and protrude slightly from the abdomen, resembling a rosebud. This appearance indicates good blood flow and proper healing. Therefore, this finding does not usually require immediate reporting to the provider.
Choice B: Stoma Oozing Red Drainage
While some minor bleeding or oozing can be normal immediately after surgery, persistent or significant red drainage from the stoma could indicate a complication such as infection or trauma to the stoma site. This finding should be monitored closely, but it is not as immediately concerning as a purplish-colored stoma, which indicates a more severe issue.
Choice C: Shiny, Moist Stoma
A shiny, moist stoma is a sign of a healthy stoma. The stoma should always appear moist and slightly shiny due to the mucus produced by the intestinal lining. This finding is normal and does not require reporting to the provider.
Choice D: Purplish-Colored Stoma
A purplish-colored stoma is an immediate concern and should be reported to the provider. This discoloration can indicate compromised blood flow to the stoma, which can lead to tissue necrosis if not addressed promptly. Ensuring adequate blood supply is crucial for the stoma’s viability and the patient’s overall health. Immediate medical intervention is necessary to prevent further complications.
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