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: Ammonia
Lactulose is administered to patients with hepatic encephalopathy to reduce the levels of ammonia in the blood. Hepatic encephalopathy occurs due to the liver’s inability to detoxify ammonia, a byproduct of protein metabolism. Lactulose works by converting ammonia into ammonium, which is then excreted in the stool. This helps to lower blood ammonia levels and alleviate the symptoms of hepatic encephalopathy.
Choice B: Dysarthria
Dysarthria, or difficulty in articulating words, is a common symptom of Parkinson’s disease. It results from the muscle rigidity and bradykinesia (slowness of movement) that affect the muscles involved in speech. Patients with Parkinson’s often have a soft, monotone voice and may struggle with the clarity of their speech.
Choice C: Muscle Rigidity
Muscle rigidity is one of the hallmark symptoms of Parkinson’s disease. It refers to the stiffness and inflexibility of the muscles, which can affect any part of the body. This rigidity can lead to discomfort and pain, and it contributes to the characteristic stooped posture and shuffling gait seen in Parkinson’s patients.
Choice D: Seizures
Seizures are not typically associated with Parkinson’s disease. While Parkinson’s affects the central nervous system, it primarily impacts motor function rather than causing seizure activity. Therefore, this is not a common finding in Parkinson’s patients.
Choice E: Drooling at Times
Drooling, or sialorrhea, is a common symptom in Parkinson’s disease. It occurs due to the decreased ability to swallow saliva, which can result from muscle rigidity and bradykinesia affecting the muscles involved in swallowing. This can be particularly bothersome for patients and may require management strategies.
Choice F: Mask-like Facial Expression
A mask-like facial expression, also known as hypomimia, is a common feature of Parkinson’s disease. It results from the rigidity and bradykinesia affecting the facial muscles, leading to reduced facial expressions and a fixed, staring appearance.
Choice G: Shuffled Gait
A shuffled gait is a characteristic feature of Parkinson’s disease. Patients often take small, shuffling steps and may have difficulty initiating movement. This gait pattern is due to the combination of muscle rigidity, bradykinesia, and postural instability.
Choice H: Stooped Posture
Stooped posture is another common symptom of Parkinson’s disease. It results from the muscle rigidity and postural instability that affect the patient’s ability to maintain an upright position. This can lead to a forward-leaning posture and balance issues.
Correct Answer is C
Explanation
Choice A reason:
Strict monitoring of hourly intake and output is important for managing fluid balance and detecting potential complications such as dehydration or fluid overload1. However, it is not the highest priority in the acute phase of bacterial meningitis. The primary concern is to monitor for signs of increased intracranial pressure (ICP) and neurological deterioration.
Choice B reason:
Managing pain through drug and non-drug methods is essential for patient comfort and overall well-being. Pain management can help reduce stress and improve the patient’s ability to rest and recover. However, it is not the highest priority compared to monitoring neurological status, which can provide early indications of complications such as increased ICP or seizures.
Choice C reason:
Assessing neurological status at least every 2 to 4 hours is the highest priority for a client with bacterial meningitis. This frequent assessment helps detect early signs of neurological deterioration, increased ICP, and other complications. Early detection and intervention are crucial in preventing severe outcomes and improving the patient’s prognosis.
Choice D reason:
Decreasing environmental stimuli is important to reduce stress and prevent exacerbation of symptoms such as headache and photophobia. While this intervention is beneficial, it is not as critical as frequent neurological assessments in the acute management of bacterial meningitis.
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