What is a primary nursing responsibility after obtaining a blood specimen for ABGs?

Palpation is used to assess finger clubbing, tracheal deviation, limited chest expansion, and increased tactile fremitus. These findings provide important information about underlying respiratory or cardiac abnormalities and help identify structural or functional changes in the lungs and thorax.

Rationale for correct answers:
2. Finger clubbing. Palpation of the nail beds can confirm the presence of clubbing, which indicates chronic hypoxemia associated with conditions such as lung cancer, bronchiectasis, or chronic obstructive pulmonary disease (COPD).
3. Tracheal deviation. By gently palpating the trachea at the suprasternal notch, the nurse can detect deviation from the midline, which may occur with pneumothorax, pleural effusion, or atelectasis.
4. Limited chest expansion. Placing hands on the posterior chest wall allows the nurse to assess for symmetry and depth of chest movement during respiration. Decreased or asymmetric expansion may indicate lung collapse, pleural effusion, or pneumonia.
5. Increased tactile fremitus. Palpation while the patient repeats a phrase (e.g., “ninety-nine”) can detect vibration transmission through the chest wall. Increased fremitus suggests lung consolidation, as in pneumonia, where sound waves travel more efficiently through dense tissue.

Rationale for incorrect answers:
1. Stridor. Stridor is a high-pitched inspiratory sound heard primarily with auscultation, not palpation.
6. Use of accessory muscles. The use of neck and shoulder muscles during breathing is observed visually, not palpated.

Take-home points:

• Palpation assesses structural alignment, symmetry, movement, and tactile vibrations of the chest.
• Key abnormal findings include tracheal shift, limited expansion, fremitus changes, and clubbing.
• Auscultation and inspection are used for detecting breath sounds and muscle use, not palpation.
• Combined use of inspection, palpation, percussion, and auscultation ensures a complete respiratory assessment.

A low pulse oximetry reading may occur due to factors that interfere with accurate detection of oxygen saturation, such as nail polish, inadequate peripheral circulation, and edema. These conditions can prevent the oximeter’s light sensor from properly detecting arterial oxygen levels, leading to falsely low readings even when the patient’s oxygenation is normal.

Rationale for correct answers:
1. Nail polish. Dark-colored nail polish or artificial nails can block or distort the light signal used by the pulse oximeter, resulting in inaccurate or falsely low readings. The nurse should remove nail polish or use an alternate sensor site, such as the earlobe or toe, to obtain a reliable measurement.

2. Inadequate peripheral circulation. Poor blood flow, as seen in hypotension, hypothermia, or peripheral vascular disease, reduces the pulsatile flow required for accurate pulse oximetry readings. This can cause the device to register a lower saturation level than the actual arterial oxygen concentration.

5. Edema. Tissue swelling, especially in the fingers, interferes with the light transmission and absorption used by the oximeter. This results in unreliable or falsely low readings because the sensor cannot effectively detect the pulsating arterial blood.

Rationale for incorrect answers:
3. Hyperthermia. Elevated body temperature typically increases peripheral circulation and does not contribute to a low oxygen saturation reading. In some cases, it may even improve signal accuracy.
4. Increased hemoglobin (Hgb) level. A higher hemoglobin concentration enhances the blood’s oxygen-carrying capacity and does not lower pulse oximetry readings. In fact, pulse oximetry measures the percentage of hemoglobin saturated with oxygen, not the total hemoglobin level.

Take-home points:

• Nail polish, poor circulation, and edema can lead to falsely low pulse oximetry readings.
• Always verify low readings by reassessing with a clean, well-perfused site or using arterial blood gases (ABGs) for accuracy.
• Pulse oximetry readings should always be interpreted in conjunction with the patient’s overall clinical presentation.