Specimen Collection: Sputum by Suction (Respiratory Therapy)

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Specimen Collection: Sputum by Suction (Respiratory Therapy)


Hyperoxygenate the patient and closely monitor the patient’s vital signs before and after the sputum collection suctioning procedure.

Don appropriate personal protective equipment (PPE) based on the patient’s signs and symptoms and indications for isolation precautions.


Sputum is produced by cells lining the respiratory tract. It is normal for healthy lungs to produce sputum, but certain conditions can change the characteristics of sputum or increase the amount of sputum produced. Sputum collection may be used to diagnose and determine treatment for a respiratory infection.

Suctioning may be needed to collect sputum from patients unable to spontaneously produce a sputum sample for laboratory analysis. Although suctioning may be a necessary procedure, it may provoke violent coughing or gagging, which may lead to vomiting or laryngeal or bronchial spasms.undefined#ref3">3 In addition, there may be other adverse responses such as hypoxemia, cardiac dysrhythmias due to vagal nerve stimulation, mucosal trauma, and increased intracranial pressure.1,3 Generally, suctioning is well tolerated with minor discomfort and adverse reactions.

The oropharynx can be suctioned using a rigid tonsil tip suction catheter or Yankauer suction catheter before sputum collection from the lower airways. The lower airways may be suctioned through the nose (nasotracheal suctioning) or through an artificial airway (endotracheal or tracheostomy tube suctioning). The two techniques used for artificial airway suctioning for sputum collection include the open method (Figure 1)Figure 1, which uses a single-use open catheter primarily on patients who do not require mechanical ventilation, and the closed method (Figure 2)Figure 2, which uses a sterile sleeved closed suction catheter that does not require disconnection from the ventilator. For patients who require mechanical ventilation, the closed method using the sleeved closed suction catheter is preferred to reduce the incidence of hypoxemia and lung derecruitment, which may occur when the patient is disconnected from the ventilator.3 Sputum collection should be performed using proper sterile technique so that the sputum specimen is fresh and uncontaminated.

Sputum specimens may be collected for many reasons but the most common are microscopic examination using a direct smear and culture and sensitivity. The direct smear uses a staining method that helps determine the type or shape of microorganism in the specimen. The culture and sensitivity test identifies specific microorganisms that cause the respiratory infection and helps to determine the most effective antibiotic treatment.4


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  • Provide developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, and overall neurologic and psychosocial state.
  • Explain to the patient and family that coughing, gagging, or (less common) sneezing can occur because of the cough reflex.
  • Explain to the patient and family that the use of suctioning is a necessary part of patient care.
    • Suctioning removes mucus from the airways to prevent infection and make breathing easier.
    • Suctioning is a way to collect a sputum (mucus) sample from the lungs to determine if there is a respiratory infection and the best way to treat it.
  • Demonstrate the proper splinting technique for postoperative patients.
  • If aerosol treatment is indicated, teach the purpose of the procedure. Explain that the aerosol treatment may loosen the mucus and stimulate coughing so that it is easier to obtain the sputum specimen.
  • Encourage the patient to cough during the procedure to assist in expelling mucus from the upper airway.
  • Encourage questions and answer them as they arise.



  1. Perform hand hygiene before patient contact. Don appropriate PPE based on the patient’s need for isolation precautions or the risk of exposure to bodily fluids.
  2. Introduce yourself to the patient.
  3. Verify the correct patient using two identifiers.2
  4. Verify the practitioner’s order for the type of sputum analysis and specifications (e.g., amount of sputum, number of specimens, time of collection, method to obtain).
  5. For the patient without an artificial airway, ensure the patient has not recently eaten or used toothpaste or mouthwash because this may contaminate the sputum specimen.
  6. Determine the type of patient assistance needed to obtain a specimen.
  7. Assess the patient’s vital signs, including oxygen saturation (SpO2), respiratory rate (RR), heart rate (HR), blood pressure (BP), and color.
  8. Auscultate the patient’s breath sounds.
  9. Assess the need for suctioning.
  10. Instruct the patient to breathe normally during suctioning to prevent hyperventilation.


  1. Prepare the vacuum suction source (wall or portable) and suction tubing to determine proper function.
  2. Set the suction regulator to 120 to 150 mm Hg3 for adults (no greater than what is required to remove secretions adequately).
  3. Gather additional equipment needed for the specimen collection, including open sterile suction catheter or new sleeved closed suction catheter, inline sterile specimen container (sputum trap), and PPE.
  4. Ensure that an oxygen source is available for patient hyperoxygenation before and after the procedure.


  1. Perform hand hygiene and don gloves, gown, mask, and eye protection or face shield.
  2. Verify the correct patient using two identifiers.2
  3. Explain the procedure and ensure that the patient agrees to treatment.
  4. Position the patient in high Fowler or semi-Fowler position.
    Rationale: High Fowler or semi-Fowler positioning promotes full lung expansion and facilitates the patient’s ability to cough.
    If the patient has a surgical incision or localized area of discomfort, instruct the patient to either place the hands firmly over the affected area or to place a pillow over the area.
    Rationale: Splinting the painful area minimizes muscular stretching and discomfort during coughing, which makes coughing more productive.
  5. Auscultate the patient’s breath sounds before and after the suctioning procedure and specimen collection.
  6. Connect the suction tubing from the vacuum suction source to the hard-plastic adapter on the sputum trap.
    1. If using a sleeved suction catheter, remove the suction tubing from the end of the catheter and connect it to the hard-plastic adapter on the sputum trap.
    2. If using an open suction catheter (single use), connect the suction tubing to the hard-plastic adapter on the sputum trap.
      If using the sleeved suction catheter or closed suction method (Figure 2)Figure 2, ensure that the sleeved suction catheter is new and uncontaminated.
  7. Preoxygenate the patient for 30 to 60 seconds.3
  8. If using an open sterile suction catheter, remove gloves, perform hand hygiene, and don sterile gloves to avoid contaminating the outside of the container.
  9. Connect the sterile open suction catheter (Figure 1)Figure 1 or the end of the sleeved suction catheter (Figure 2)Figure 2 to the soft rubber tubing on the sputum trap without contaminating the catheter or the sputum trap.
  10. Oxygenate the patient as needed.
  11. Gently insert the tip of the suction catheter through the endotracheal tube, nasopharynx, or tracheostomy tube without applying suction.
    Rationale: Inserting the catheter without applying suction minimizes hypoxemia and trauma to the airway as the catheter is inserted.
  12. Advance the catheter into the endotracheal tube, nasopharynx, or tracheostomy tube gently and quickly. Only advance the catheter to the end of the endotracheal or tracheostomy tube.
    Rationale: Entrance of the catheter into the larynx and trachea usually triggers the cough reflex.
  13. As the patient coughs, apply suction and gently withdraw the catheter. Limit the aspiration time to 15 seconds or less.3 Apply suction by placing the thumb of the nondominant hand over the suction port of the regular suction catheter or by depressing the suction button of the sleeved suction catheter.
    Suctioning longer than 15 seconds can cause hypoxia and mucosal damage.3
    If the patient shows signs of becoming hypoxemic during the procedure, discontinue the procedure immediately and provide oxygen as ordered.
  14. Release suction and completely remove the catheter from the endotracheal tube, nasopharynx, or tracheostomy tube.
  15. Reoxygenate the patient and allow a short rest period for the patient to catch the breath and for oxygenation to return to baseline.
  16. Continue the procedure until enough of a specimen has been collected.
  17. Detach the catheter from the specimen trap.
    1. If using a sterile open suction catheter, dispose of it in the appropriate receptacle.
    2. If using a sleeved closed suction catheter, reconnect the suction tubing to the end of the closed suction catheter.
  18. For the sputum trap, detach the suction tubing and connect the soft rubber tubing on the sputum trap to the hard-plastic adapter.
  19. Secure the top of the specimen container tightly.
  20. In the presence of the patient, label the specimen per the organization’s practice.2
  21. Place the labeled specimen in a biohazard bag and transport it to the laboratory immediately per the organization’s practice.
  22. Oxygenate the patient as needed.
  23. Discard supplies, remove PPE, and perform hand hygiene.
  24. Document the procedure in the patient’s record.


  1. Observe the patient’s respiratory status throughout the procedure, especially during suctioning.
    Rationale: Excessive coughing or prolonged suctioning can alter the patient’s respiratory pattern and cause hypoxia.
  2. Auscultate the patient’s breath sounds before and after the suctioning procedure and specimen collection.
  3. Observe the patient for anxiety or discomfort.
    Rationale: The procedure can be uncomfortable. If the patient becomes short of breath, anxiety may develop.
  4. Observe the patient for signs and symptoms of pain. If pain is suspected, report it to the authorized practitioner.


  • Vital signs, including HR, RR, BP, and SpO2, return to baseline.
  • Oxygenation status is not compromised.
  • Adequate amount of sputum is collected.
  • Sputum specimen is not contaminated.


  • Hypoxemia
  • Increased respiratory rate and effort
  • Shortness of breath
  • Anxiety
  • Inadequate amount of sputum collected
  • Contaminated sputum specimen
  • Pain or discomfort


  • Method used to obtain specimen
  • Hyperoxygenation steps
  • Date and time of collection
  • Type of test ordered
  • Characteristics of sputum specimen, including amount, color, and consistency
  • Vital signs, including HR, RR, BP, and SpO2
  • Breath sounds
  • Patient’s tolerance of procedure
  • Education
  • Unexpected outcomes and related interventions


  1. American Association for Respiratory Care (AARC). (2010). AARC clinical practice guidelines: Endotracheal suctioning of mechanically ventilated patients with artificial airways 2010. Respiratory Care, 55(6), 758-764. (classic reference)* (Level VII)
  2. Joint Commission, The. (2022). National Patient Safety Goals for the hospital program. Retrieved May 25, 2022, from (Level VII)
  3. La Vita, C.J. (2021). Chapter 37: Airway management. In R.M. Kacmarek, J.K. Stoller, A.J. Heuer (Eds.), Egan’s fundamentals of respiratory care (12th ed., pp. 748-787). St. Louis: Elsevier.
  4. Prestholdt, F.J. (2022). Chapter 7: Clinical laboratory studies. In A.J. Heuer (Ed.), Wilkins’ clinical assessment in respiratory care (9th ed., pp. 117-140). St. Louis: Elsevier.

*In these skills, a “classic” reference is a widely cited, standard work of established excellence that significantly affects current practice and may also represent the foundational research for practice.

Elsevier Skills Levels of Evidence

  • Level I - Systematic review of all relevant randomized controlled trials
  • Level II - At least one well-designed randomized controlled trial
  • Level III - Well-designed controlled trials without randomization
  • Level IV - Well-designed case-controlled or cohort studies
  • Level V - Descriptive or qualitative studies
  • Level VI - Single descriptive or qualitative study
  • Level VII - Authority opinion or expert committee reports