10.3: Sputum Collection
By the end of this section, you will be able to:
- Describe the chemical, physical, and microscopic characteristics of sputum, nasal secretions, and throat cells
- Verbalize the steps in collecting sputum, nasal, and oropharyngeal specimens
- Interpret the results of sputum, nasal, and oropharyngeal specimens
Sputum, nasal, and throat analyses offer valuable insights into the respiratory health of our patients, aiding in the diagnosis and management of a wide range of conditions. Understanding the chemical, physical, and microscopic characteristics of sputum, nasal secretions, and throat cells provides a foundation for recognizing abnormalities. As a nurse, you will be responsible for collecting sputum, nasal, and oropharyngeal specimens, ensuring accurate and contamination-free sampling. By knowing the normal characteristics of sputum, nasal secretions, and throat cells, you will be able to interpret the results of specimen testing, enabling you to make informed clinical decisions and deliver the best possible care to your patients.
Sputum, Nasal, and Throat Specimen Overview
Mucus and other secretions that are coughed up from the lungs and expectorated through the mouth are called sputum . The body normally produces mucus to keep the delicate tissues of the respiratory tract moist so small particles of foreign matter can be trapped and forced out. Sputum can exhibit various chemical, physical, and microscopic characteristics that are valuable for diagnostic purposes. These characteristics can provide important insights into the patient’s respiratory health.
Nasal and oropharynx specimens are most commonly used for the detection of pathogenic microorganisms in the nose and throat. The oropharynx is the part of the throat at the back of the mouth behind the oral cavity. It includes the back third of the tongue, the soft palate, the side and back walls of the throat, and the tonsils. Microscopic examination of nasal and oropharynx swabs are used to detect the presence of microorganisms, such as bacteria, fungi, or parasites.
Purpose
A sputum culture is a diagnostic test that evaluates the type and number of bacteria present in sputum. The patient is asked to cough deeply and spit any mucus that comes up into a sterile specimen container. The sample is sent to a lab where it is placed in a special dish (Figure 10.4) and watched for two to three days or longer to see if bacteria or other disease-causing germs grow.
Sputum cytology is also a critical component of a lung cancer diagnosis. It involves examining sputum samples for the presence of abnormal or cancerous cells and can help detect lung cancer at an early stage. It can also be used for diagnosis of chronic respiratory conditions such as chronic obstructive pulmonary disease (COPD) or asthma, and performed periodically to monitor disease progression and guide treatment. Sputum samples can also be collected before and during treatment for respiratory conditions to help assess the effectiveness of therapy.
Nasal and oropharyngeal swab s are commonly used to diagnose respiratory infections, including viral infections like COVID-19, influenza, the common cold, and bacterial infections such as streptococcal infections (strep throat). By collecting samples from the upper respiratory tract, healthcare providers can detect the presence of pathogens responsible for these infections. The specific purpose of the swab test may vary depending on the clinical context and the suspected pathogen. For example, the COVID-19 swab test, which uses a nasopharyngeal or oropharyngeal swab, is used to detect the presence of SARS-CoV-2, while an oropharyngeal swab is used to identify Streptococcus bacteria.
Types of Sputum, Nasal, and Oropharyngeal Collections
There are several methods for collecting sputum samples for diagnostic and clinical purposes, each depending on the specific diagnostic goals and the patient’s condition. Some common types of sputum collection methods include the following:
- In spontaneous sputum collection , the patient coughs up sputum and spits it into a sterile container.
- In induced sputum collection , a hypertonic saline or other aerosolized agent may be used to induce sputum production in cases where the patient has difficulty producing sputum. The patient inhales the agent, which loosens mucus and makes it easier to cough it up for collection.
- In nasotracheal suction collection , a nasotracheal suction catheter may be used to collect sputum directly from the lower respiratory tract in patients who are unable to produce sputum or when deeper respiratory samples are required. This method is typically used in more critical or ventilated patients.
- In bronchoscopy collection , an invasive procedure, a thin, flexible tube with a camera is inserted into the airways. During this procedure, a healthcare provider can collect sputum samples from specific areas within the respiratory system for diagnostic purposes.
- A sputum trap may be used in some cases. Healthcare facilities may use this specialized collection device that attaches to the patient’s breathing equipment (such as ventilators) to collect sputum samples.
There are several methods for collecting nasal and oropharyngeal specimens for diagnostic and clinical purposes. Some common types of nasal and oropharyngeal collection methods include the following:
- For a nasal swab , a swab is used to collect a sample from the inside of the nasal passage.
- For a nasopharyngeal swab , a swab is used to collect a sample from the nasopharynx, which is the upper part of the throat that connects to the back of the nasal cavity.
- For an oropharyngeal swab , a swab is used to collect a sample from the oropharynx, which is the part of the throat at the back of the mouth.
Procedural Steps for Sputum, Nasal, and Oropharyngeal Collection
Prior to implementing sputum specimen collection, it is helpful to ensure the patient is well hydrated. Hydration helps thin and loosen sputum and increases the likelihood of obtaining an adequate sample. If the patient is prescribed nebulizer treatments, it is helpful to administer this treatment prior to the procedure to help mobilize secretions. It is also important to assess if the patient is experiencing pain related to coughing. For example, pain following chest or abdominal surgery can inhibit the patient from taking deep breaths and expectorating. In this case, pain medication should be provided prior to performing the procedure. Patients can also be encouraged to support surgical wounds with a pillow while coughing to provide additional support and comfort.
See the competency checklist for Collecting a Sputum Specimen. You can find the checklists on the Student resources tab of your book page on openstax.org.
It is best to obtain sputum samples in the early morning because secretions accumulate overnight. The patient can rinse their mouth with water prior to the procedure, but avoid mouthwash or toothpaste because these products can affect the microorganisms in the sample. Remove dentures if they are present.
Be aware that droplets and aerosols may be generated when collecting sputum specimens, so use appropriate personal protective equipment when entering the room and during the procedure based on the patient’s condition. Explain the procedure to the patient, the type of specimen required, and the difference between oral secretions and sputum . Identify the patient with name and date of birth, matching with patient verbally and checking ID bands. Preprinted labels should be verified too. Position the patient in a seated position in a chair or at the side of the bed or place them in high Fowler position.
Instruct the patient to take three slow, deep breaths and then cough deeply. Repeat this process until the patient has produced sputum, with rest periods between each maneuver.
When the patient has mobilized sputum, instruct them to expectorate directly into a sterile specimen container without touching the inside or rim of the container. The specimen should be at least 5 mL (one teaspoon); ask the patient to continue producing and expectorating sputum until this amount is achieved. Assess the sputum specimen to ensure it is sputum and not saliva. Sputum appears thick and opaque, whereas saliva appears thin, clear, and watery.
Cap the specimen container tightly, and ensure it is labeled with the patient’s name. Place the specimen in a transport bag, and send it to the laboratory for analysis. Document the time and date the sputum specimen was collected and the characteristics of the sputum, including amount and color.
If a patient is unable to expectorate a sputum sample, other interventions may be required to mobilize secretions. It is often helpful to collaborate with a respiratory therapist for assistance in this situation. Interventions may include nebulizers, hydration, deep-breathing exercises, chest percussion, and postural drainage. If these interventions are not successful, a sputum sample may be obtained via oropharyngeal or endotracheal suctioning; these methods are used to obtain sputum samples for patients who are intubated.
When performing a nasal swab , gently insert the sterile swab into the patient’s nostril (Figure 10.5) (Centers for Disease Control and Prevention [CDC], 2022). The swab should be directed upward and backward along the floor of the nasal passage, following the natural curvature of the nasal cavity. The swab should be advanced to a depth of about 1 to 1.5 in (2.5 to 4 cm). Rotate the swab gently for about ten to fifteen seconds to ensure that it comes into contact with the nasal mucosa, which contains the cells and secretions necessary for the test.
To collect a nasopharyngeal swab test, ask the patient to tilt their head slightly backward to help access the nasopharynx more easily. Remove the swab from the packaging. Gently insert the sterile swab through one of the patient’s nostrils, and advance it approximately the distance equivalent from the ear to the nostril of the patient (Figure 10.5) (CDC, 2022). The swab should be directed posteriorly, following the natural curvature of the nasal passage. If you meet resistance, try reinserting the swab at a different angle or use the other nostril; however, do not force the swab.
Once the swab has reached the nasopharynx, gently rotate it for several seconds to collect the sample. This may induce a gag reflex or cause mild discomfort, but it is usually brief. Slowly withdraw the swab while continuing to rotate it to ensure maximum sample collection. Carefully remove the swab from the nostril and place it in the sterile collection tube, according to manufacturer’s guidelines. The swab should be inserted into the tube swab-first and typically involves breaking the swab off at an etched groove so the lid can be placed on the tube. Properly label the container with the patient’s identifying information, including the patient’s name, date of birth, date and time of collection, and other details according to facility policy. Place the collection tube in a biohazard bag and transport the sample to the laboratory according to facility procedure.
See the competency checklist for Collecting a Nasopharyngeal Sample. You can find the checklists on the Student resources tab of your book page on openstax.org.
The procedure for collecting an oropharyngeal specimen is similar to collecting a nasopharyngeal specimen; however, the swab is inserted in the mouth and directed toward the back of the throat (Figure 10.7) (CDC, 2022). Instruct the patient to open their mouth and say “ahh.” Avoid touching the tongue, teeth, and gums. Gently swab the back of the throat and the tonsils (if present). Ensure that the swab comes into contact with the oropharyngeal area for several seconds to collect an adequate sample. A tongue depressor may be used to hold the tongue down, if necessary, to better visualize the throat. Like nasopharyngeal testing, oropharyngeal testing may induce a gag reflex or cause mild discomfort; however, it is usually brief.
Documentation of Sputum, Nasal, and Oropharyngeal Collection
Documenting sputum , nasal, and oropharyngeal collections is an important part of the diagnostic process, as it helps ensure proper tracking and identification of samples, which is crucial for accurate diagnosis and treatment. Always follow the specific documentation procedures and guidelines set by the healthcare facility to ensure consistency and accuracy in the documentation process.
Documentation should include:
- type, date, time, and quality of the specimen
- recent antibiotic therapy
- appearance of the oral mucosal and/or nasal structures
- patient’s tolerance of the procedure
- any unexpected outcomes or interventions
- teaching provided to the patient and family, including understanding of the teaching and any follow-up teaching needed
Patient Education
Patient education is a crucial part of sputum collection to ensure that the process is done effectively, comfortably, and with minimal risk of contamination. Be sure to cover the following:
- why sputum collection is necessary
- the ideal time for sputum collection, such as in the morning when sputum production is often highest
- the importance of refraining from eating or drinking for at least thirty minutes before collecting sputum to minimize saliva contamination
- good handwashing before collecting sputum
- proper use of the sputum collection container
- coughing technique
- importance of avoiding contaminating sputum with saliva
Inform the patient about when and how they will receive the results of their sputum analysis. If the patient has an infectious respiratory condition, explain the importance of good respiratory hygiene. Encourage patients to ask questions and seek clarification if needed to ensure they feel confident in the process. Provide contact information for questions or concerns.
Before performing a nasal or oropharyngeal swab on a patient, it is important to provide clear and reassuring instructions to help the patient understand the procedure, what to expect during the collection process, and alleviate any concerns. It is important to educate patients that retrieval of throat specimens may initiate a gag reflex. If gagging occurs, it will be brief. The patient should try to remain still, avoid pulling away, and take deep breaths through their nose.
Interpretation of Results
Interpreting sputum, nasal, and throat specimen results is a critical part of diagnosing and managing respiratory conditions and infections. Specimen analysis provides valuable insights into the nature of respiratory illnesses and can guide healthcare providers in making informed decisions regarding treatment and care. This section reviews normal and abnormal findings as well as factors affecting the results.
Normal Findings
When considering the normal findings of sputum , it is important to note that what is considered “normal” can vary among individuals. What may be considered “normal” for a healthy individual could be different from what is expected in the context of diagnosing or monitoring specific respiratory conditions. Normal sputum, in a healthy individual, should typically have no color or smell and should not contain blood or microorganisms (Table 10.6).
| Characteristic | Result |
|---|---|
| Color | Clear, white, or slightly yellow |
| Consistency | Thin, watery |
| Odor | None |
| Volume | Small amount, not excessive |
| Clarity | Transparent or slightly cloudy |
| Viscosity | Not overly viscous or sticky |
| Blood | Negative |
| Microorganisms | Negative |
Normal findings in nose and throat specimens generally mean there are no signs of viral or bacterial pathogens. Normal nasal and oropharyngeal swabs will be negative for viruses (e.g., influenza, common cold viruses) or bacteria (e.g., Staphylococcus aureus , Streptococcus pyogenes ) responsible for respiratory infections.
Abnormal Findings
Abnormal findings in a sputum sample indicate the presence of various respiratory conditions, infections, or other health issues. Characteristics of abnormal sputum can be found in Table 10.7.
| Characteristic | Description |
|---|---|
| Color |
Yellow or green (purulent) sputum often suggests a bacterial respiratory infection, such as bronchitis or pneumonia.
Brown or rusty-colored sputum may indicate the presence of old blood. Red or pink sputum (hemoptysis) may suggest active bleeding in the respiratory tract, which could be caused by various conditions, including lung cancer, tuberculosis, or bronchitis. |
| Consistency | Abnormal sputum may be thick and sticky. |
| Odor | An unpleasant or foul odor in sputum can be indicative of a bacterial or fungal infection. |
| Volume | Sputum samples with an abnormally high volume of thick, sticky mucus may be observed in conditions like cystic fibrosis. |
| Clarity | Abnormal sputum may be cloudy. |
| Viscosity | Abnormal sputum may be viscous and sticky. |
| Presence of blood | Abnormal sputum may contain blood. |
| Presence of white blood cells (leukocytosis) | Elevated levels of white blood cells (leukocytes) in sputum are often indicative of an inflammatory response to infection or other respiratory conditions. |
| Presence of microorganisms | Identification of specific bacterial species in sputum may indicate bacterial respiratory infections like pneumonia or bronchitis. |
| Cytological abnormalities | The presence of abnormal or cancerous cells in sputum is a critical finding that may suggest lung cancer or precancerous changes. |
| Inflammatory cells | Elevated levels of eosinophils in sputum may be indicative of conditions like asthma or eosinophilic lung diseases. The presence of neutrophils and other inflammatory cells can help identify the nature of the inflammation and the underlying cause. |
| Crystals | Charcot-Leyden crystals found in sputum are often associated with eosinophilic inflammation and may be seen in conditions like asthma or parasitic lung infections. |
It is important to note that sputum analysis is just one component of the diagnostic process. Abnormal findings in sputum are typically considered alongside the patient’s clinical history, physical examination, imaging studies, and other tests to make an accurate diagnosis and guide treatment decisions.
Abnormal findings in nose and throat specimens generally mean there are signs of viral or bacterial pathogens. Abnormal nasal and throat swabs will show evidence of viruses (e.g., influenza, common cold viruses) or bacteria (e.g., Staphylococcus aureus , Streptococcus pyogenes ) responsible for respiratory infections.
Factors Affecting Results
There are a number of factors that can affect sputum results, influencing the characteristics of the sample and the accuracy of diagnostic information. Healthcare providers and laboratory professionals must be aware of these factors when interpreting sputum results:
- deviations from standard collection process
- inability to collect a quality sample
- contamination of the specimen
- patient compliance
- certain medications that can alter sputum
- certain foods that can alter the color of sputum
- underlying patient conditions or environmental exposures
- improper transport or storage of specimen
Age-related factors can affect sputum results, particularly for older adults. For example, age-related changes in the respiratory system, such as reduced lung function and weakened cough reflexes, can impact sputum production. Therefore, older adults may have a harder time generating sufficient sputum for collection and may not have the physical strength to generate a productive cough. Sputum consistency also alters with increased age. Sputum from older adults may be thicker and more viscous due to age-related changes in mucous production and clearance mechanisms. Older adults are also more prone to respiratory conditions like COPD and pneumonia, which can affect sputum characteristics. For example, COPD often leads to increased mucous production, thicker and more viscous sputum, blood in the sputum, and changes to sputum color (such as yellow, green, or even brown).
Collecting a sputum sample from an older adult with cognitive impairments, such as dementia, can present several challenges. These individuals may have difficulty understanding instructions, following through with the procedure, or expressing discomfort. Older adults with cognitive impairments often have limited ability to cooperate during the sputum collection process and may not comprehend the need for the procedure or may resist it due to confusion or anxiety. Cognitive impairments can also lead to anxiety and agitation during unfamiliar medical procedures, which can make the sputum collection process distressing for the individual and challenging for healthcare providers. In many cases, caregivers or healthcare providers may need to assist with sputum collection to ensure the safety and comfort of the patient.
There are also several factors that can affect the accuracy and reliability of nasal and throat specimens. The way the specimen is collected, including the swabbing technique and the depth to which the swab is inserted, can significantly affect the results, as improper collection may result in inadequate sample retrieval or contamination. The timing of specimen collection in relation to the onset of symptoms can impact results, as some infections may not be detectable in the early stages of illness or may have already cleared by the time the test is performed. The choice of swab can affect the results, as the swab should be designed for the specific diagnostic test. Medications such as antibiotics and antivirals can impact the results. For example, if a patient has already started antibiotic or antiviral treatment, it may impact the ability to detect the pathogen in the sample. Understanding these factors is essential to ensure nasal and throat samples are collected and analyzed accurately.