Chapter 27: Thoracentesis

Question 1

A nurse is assisting with a thoracentesis. Which of the following actions should the nurse take to ensure patient safety during the procedure?

a. Encourage the patient to lie supine during the procedure.
b. Instruct the patient to avoid coughing during the procedure.
c. Administer high-flow oxygen to the patient during the procedure.
d. Monitor the patient’s urine output throughout the procedure.

Answer 1

b. Instruct the patient to avoid coughing during the procedure.

Rationale: Coughing or sudden movements during thoracentesis can lead to needle displacement or injury to surrounding tissues and organs, such as the lungs, causing a pneumothorax. The patient is positioned upright to allow better access to the pleural space, not supine. Administering high-flow oxygen is not necessary unless the patient has pre-existing respiratory distress. Urine output monitoring is unrelated to thoracentesis safety.

Question 2

After a thoracentesis, which finding should the nurse prioritize for immediate follow-up?

a. A respiratory rate of 20 breaths per minute.
b. Blood pressure of 110/70 mm Hg.
c. Oxygen saturation of 89% on room air.
d. Clear drainage of 100 mL from the thoracentesis site.

Answer 2

c. Oxygen saturation of 89% on room air.

Rationale: Oxygen saturation of 89% is below normal limits and may indicate a pneumothorax or respiratory compromise, which are potential complications of thoracentesis. A respiratory rate of 20 breaths per minute is within normal limits. Clear drainage of 100 mL may be expected, and a blood pressure of 110/70 mm Hg is also within normal limits.

Question 3

A nurse is preparing a patient for a thoracentesis. Which patient statement indicates a need for further teaching?

a. “I will sit upright and lean on the overbed table.”

b. “I may feel some stinging when the anesthetic is injected.”

c. “I will try to remain as still as possible during the procedure.”

d. “I should take deep breaths while the doctor inserts the needle.”

Answer 3

d. “I should take deep breaths while the doctor inserts the needle.”

Rationale: The patient should avoid deep breathing during needle insertion to reduce the risk of lung puncture or displacement of the needle. Correct positioning and understanding of the local anesthetic process reflect appropriate teaching.

Question 4

Which of the following laboratory values should the nurse review prior to a thoracentesis?

a. Hemoglobin and hematocrit
b. Platelet count
c. Serum sodium levels
d. Glomerular filtration rate (GFR)

Answer 4

b. Platelet count

Rationale: Reviewing the platelet count is crucial to assess the patient’s risk for bleeding during the procedure. While hemoglobin and hematocrit provide information about overall oxygen-carrying capacity, they are not directly relevant unless active bleeding is suspected. Serum sodium and GFR are unrelated to thoracentesis.

Question 5

Which of the following is the priority nursing action immediately following a thoracentesis?

a. Obtain a chest X-ray.
b. Position the patient on the unaffected side.
c. Administer prescribed antibiotics.
d. Perform sterile dressing changes.

Answer 5

a. Obtain a chest X-ray.

Rationale: A chest X-ray is typically performed post-thoracentesis to rule out complications such as pneumothorax. While dressing the site is necessary, it is not the priority. Positioning the patient on the unaffected side may be needed for comfort but does not take precedence over ruling out complications.

Question 6

A patient reports sudden chest pain and difficulty breathing shortly after a thoracentesis. What complication does the nurse suspect?

a. Atelectasis
b. Pneumothorax
c. Pleural effusion
d. Pulmonary embolism

Answer 6

b. Pneumothorax

Rationale: Pneumothorax is a potential complication of thoracentesis due to accidental puncture of the lung. Symptoms include sudden chest pain, dyspnea, and decreased oxygen saturation. Atelectasis involves lung collapse due to other factors, not trauma from thoracentesis. Pleural effusion is the condition being treated, and pulmonary embolism is less likely without other risk factors.

Question 7

During a thoracentesis, the nurse observes that more than 1,500 mL of fluid is removed. What complication should the nurse monitor for in this patient?

a. Re-expansion pulmonary edema
b. Cardiac tamponade
c. Hypovolemic shock
d. Respiratory alkalosis

Answer 7

a. Re-expansion pulmonary edema

Rationale: Removing more than 1,000 to 1,500 mL of pleural fluid at one time can lead to re-expansion pulmonary edema due to rapid lung inflation. Symptoms may include respiratory distress, frothy sputum, and crackles on auscultation. Cardiac tamponade and hypovolemic shock are not common outcomes of fluid removal during thoracentesis.

Question 8

A physician orders a thoracentesis for a patient with a pleural effusion. The nurse knows the purpose of this procedure includes all of the following except:

a. Diagnosing the cause of the pleural effusion
b. Draining fluid to relieve dyspnea
c. Instilling medication into the pleural space
d. Removing a pulmonary embolism

Answer 8

d. Removing a pulmonary embolism

Rationale: Thoracentesis is not used to treat or remove a pulmonary embolism. Its primary purposes include diagnosing the cause of pleural effusion, draining fluid to relieve symptoms, and instilling medications. Pulmonary embolism requires treatment with anticoagulants or other interventions.

Question 9

A nurse is preparing a patient for a thoracentesis. Which of the following positions is most appropriate for the procedure?

a. Supine with a pillow under the knees
b. Prone with arms extended above the head
c. Sitting upright, leaning forward on an overbed table
d. Side-lying with the affected side elevated

Answer 9

c. Sitting upright, leaning forward on an overbed table

Rationale: The correct position for a thoracentesis is sitting upright and leaning forward on an overbed table, with the feet supported on the floor or a stool. This position allows optimal access to the pleural space, enabling safe needle insertion and fluid drainage. Supine, prone, or side-lying positions do not provide adequate exposure for the procedure. Additionally, lying on the affected side is contraindicated as it may hinder proper drainage or exacerbate symptoms.

Question 10

A nurse is preparing to assist with a thoracentesis. Which of the following must be completed before the procedure?

a. Administering IV fluids to prevent hypotension during the procedure

b. Positioning the patient in a lateral decubitus position

c. Explaining the procedure and obtaining signed consent

d. Administering oxygen therapy to the patient

Answer 10

c. Explaining the procedure and obtaining signed consent

Rationale: Obtaining informed consent and explaining the procedure are critical nursing responsibilities before thoracentesis. This ensures the patient understands the risks, benefits, and what to expect. The upright position is used, not lateral decubitus. IV fluids and oxygen therapy are not routinely required unless the patient has specific pre-existing conditions.

Question 11

During a thoracentesis, the patient begins coughing persistently. What is the nurse’s priority intervention?

a. Administer a cough suppressant.

b. Instruct the patient to take deep breaths to control the cough.

c. Notify the provider and remind the patient to remain still.

d. Stop the procedure and reposition the patient.

Answer 11

c. Notify the provider and remind the patient to remain still.

Rationale: Persistent coughing during a thoracentesis increases the risk of needle displacement or pleural injury, potentially causing complications such as pneumothorax. The nurse should immediately notify the provider and encourage the patient to stay still to prevent further risks. Administering a cough suppressant or stopping the procedure is not within the nurse’s independent scope in this context.

Question 12

After a thoracentesis, which assessment finding should be reported to the provider immediately?

a. Decreased breath sounds on one side
b. Blood-tinged fluid draining from the thoracentesis site
c. Pain rated 4/10 at the puncture site
d. Respiratory rate of 18 breaths per minute

Answer 12

a. Decreased breath sounds on one side

Rationale: Decreased or absent breath sounds on one side may indicate pneumothorax, a serious complication of thoracentesis. Blood-tinged fluid at the site can be normal if small amounts are observed. Pain rated 4/10 and a respiratory rate of 18 are expected findings post-procedure unless accompanied by other concerning symptoms.

Question 13

The nurse is teaching a patient post-thoracentesis care. Which statement by the patient indicates a need for further teaching?

a. “I should notify my provider if I feel short of breath or have chest pain.”

b. “I need to take deep breaths regularly to help re-expand my lungs.”

c. “I can resume my normal activities immediately after the procedure.”

d. “The fluid removed will be sent to the lab for further analysis.”

Answer 13

c. “I can resume my normal activities immediately after the procedure.”

Rationale: Patients should avoid strenuous activities for several hours after a thoracentesis to reduce the risk of complications, such as pneumothorax or bleeding. The other statements reflect proper understanding of post-procedure care, including recognizing signs of complications, promoting lung expansion, and sending fluid for laboratory analysis.

Question 14

PvO2 range

Answer 14

38-42 mmHg

Question 15

SvO2 range

Answer 15

60%-80%

Question 16

PvCO2 range

Answer 16

38-55 mmHg

Question 17

A mixed venous blood gas (SvO₂) result shows an oxygen saturation of 55%. Which of the following conditions is the most likely cause of this abnormal value?

a. Hypervolemia
b. Decreased tissue oxygen demand
c. Decreased cardiac output
d. Increased hemoglobin concentration

Answer 17

c. Decreased cardiac output

Rationale: SvO₂ below the normal range of 60%–80% often indicates inadequate oxygen delivery to tissues, which may result from decreased cardiac output. Hypervolemia and increased hemoglobin would typically enhance oxygen delivery, while decreased tissue oxygen demand would raise SvO₂, not lower it.

Question 18

A nurse is interpreting a patient’s mixed venous blood gas results: pH 7.29, PvO₂ 36 mm Hg, SvO₂ 58%, PvCO₂ 60 mm Hg, HCO₃⁻ 18 mEq/L. Which acid-base imbalance does the nurse suspect?

a. Metabolic alkalosis
b. Respiratory alkalosis
c. Respiratory acidosis
d. Metabolic acidosis

Answer 18

d. Metabolic acidosis

Rationale: The pH of 7.29 indicates acidosis, and the low HCO₃⁻ (18 mEq/L) suggests a metabolic origin. The elevated PvCO₂ is likely a compensatory mechanism rather than the primary cause. Metabolic alkalosis is ruled out due to the low HCO₃⁻ and acidic pH, while respiratory causes are not supported by the provided data.

Question 19

The nurse reviews a patient’s mixed venous blood gas results: SvO₂ 85%. What is the most likely explanation for this finding?

a. Increased oxygen extraction by tissues
b. High levels of oxygen delivery relative to demand
c. Increased carbon dioxide retention
d. Acute anemia reducing hemoglobin oxygen-carrying capacity

Answer 19

b. High levels of oxygen delivery relative to demand

Rationale: An SvO₂ greater than the normal range of 60%–80% indicates that oxygen delivery exceeds tissue oxygen demand, which may occur in conditions such as hyperoxia, sepsis, or cyanide poisoning. Increased oxygen extraction would lower SvO₂, and anemia would typically reduce overall oxygen delivery.

Question 20

A patient with mixed venous blood gas values showing PvCO₂ 60 mm Hg and pH 7.35 is in which acid-base state?

a. Fully compensated respiratory acidosis
b. Fully compensated metabolic alkalosis
c. Partially compensated respiratory acidosis
d. Partially compensated metabolic acidosis

Answer 20

a. Fully compensated respiratory acidosis

Rationale: The PvCO₂ of 60 mm Hg indicates hypercapnia, typically causing respiratory acidosis. However, the pH is within the normal range (7.35–7.45), indicating full compensation by renal retention of bicarbonate. Metabolic alkalosis and acidosis are not supported by the given data.

Question 21

A patient’s mixed venous blood gas shows: pH 7.38, PvO₂ 40 mm Hg, SvO₂ 60%, PvCO₂ 52 mm Hg, and HCO₃⁻ 26 mEq/L. What conclusion can the nurse make about this patient’s condition?

a. The patient is in uncompensated metabolic alkalosis.
b. The patient has compensated respiratory acidosis.
c. The patient is experiencing uncompensated respiratory acidosis.
d. The results are within normal limits.

Answer 21

b. The patient has compensated respiratory acidosis.

Rationale: The PvCO₂ is elevated (normal: 38–55 mm Hg), suggesting respiratory acidosis. However, the pH is within the normal range, indicating that the condition is fully compensated. The bicarbonate (HCO₃⁻) is normal, which aligns with full compensation rather than an uncompensated state.

Question 22

The nurse prepares a patient who has a left-sided pleural effusion for a thoracentesis. How should the nurse position the patient?

a. High-Fowler‘s position with the left arm extended

b. Supine with the head of the bed elevated 30 degrees

c. On the right side with the left arm extended above the head

d. Sitting upright with the arms supported on an over bed table

Answer 22

d. Sitting upright with the arms supported on an over bed table

Rationale: The upright position with the arms supported increases lung expansion, allows fluid to collect at the lung bases, and expands the intercostal space so that access to the pleural space is easier. the other positions would increase the work of breathing for the patient and make it more difficult for the health care provider performing the thoracentesis.

Question 23

The nurse is caring for a patient who has just had a thoracentesis. Which assessment information obtained by the nurse is a priority to communicate to the health care provider?

a. O2 saturation is 88%.

b. Blood pressure is 155/90 mm Hg.

c. Respiratory rate is 24 breaths/min when lying flat.

d. Pain level is 5 (on 0 to 10 scale) with a deep breath.

Answer 23

a. O2 saturation is 88%.

Rationale: O2 saturation should improve after a thoracentesis. A saturation of 88% indicates that a complication such as pneumothorax may be occurring. the other assessment data also indicate a need for ongoing assessment or intervention, but the low O2 saturation is the priority.