Sputum analysis

The sputum analysis consists of obtaining a sputum sample (secretions from the patient's bronchi) that will later be preserved in suitable media and taken to be analyzed in a laboratory specialized in this type of study.

Sputum analysis methods

There are different methods to analyze a sputum sample; In general terms and depending on the type of analysis used, the sputum study can be classified as:

• Macroscopic study: includes the analysis of the general characteristics of sputum such as color, consistency ... This is the basic study.
• Biochemical study: allows to establish the pH, enzymes, and other characteristic chemical elements of sputum.
• Microscopic study that in turn includes the cytological study (allows the detection of precancerous or cancerous cells, ...) and the microbiological study (allows the detection of pathogenic microorganisms).
• Special stains: Gram stain, lugol stain .... allows the detection of specific bacilli.

How the analysis is performed

Sputum analysis requires the taking of a sputum sample by the patient. In most cases, sample collection can be done by the patient himself at home. Collection of sputum from the first hour in the morning right after waking up, before eating or drinking.

Before collecting the sample, a careful cleaning of teeth and gums with your usual toothpaste (avoiding rough scratching that can cause bleeding) and a subsequent rinse with water avoiding the use of mouthwashes or mouthwashes. Once the cleaning is finished, it is recommended to take deep breaths until causing a coughing fit that the patient should take advantage of to expel sputum from his bronchial tree.

Sputum should be deposited from the mouth to a container Sterile specific for the collection of the sample that will be provided to you at the center where the study has been requested or at the pharmacy. In most cases, a small sample the size of a teaspoon may be sufficient for the study.

Once the sputum sample has been collected, the patient must deliver the closed container as soon as possible and within a maximum period of 24 hours to the center where the study has been requested, and from there it will be sent to a specialized laboratory for analysis. The sample can be kept in the refrigerator in the specific closed container until delivery.

Preparation for the study

The sputum analysis does not require any special preparation on the part of the patient. The ingestion of liquids hours before the collection of the sample can thin the secretions and favor their expulsion. Sometimes obtaining the sample can be difficult and it will be necessary to use humidifiers or mucolytics by the patient to help expel the sputum.

Certain studies will require special conditions such as avoiding taking certain drugs the days prior to collecting the sample or collecting three or more consecutive sputum samples, among others; in any case, the doctor must indicate these special conditions to the patient.

The sputum sample is taken by means of its expulsion by the patient taking advantage of a coughing fit and therefore does not imply any kind of annoyance for it. Sometimes the patient cannot expel sputum on his own and will require the use of mechanical methods or one performed by his doctor that can be bothersome.

Study risks

• The expulsion of small threads of blood intermixed with sputum due to irritation of the bronchial tree during its expulsion.
• Can occur slight chest discomfort due to the coughing spells necessary for the expulsion of sputum.
• In cases where the use of mechanical methods or a bronchoscopy is necessary to obtain the sample, the following must be taken into account. inherent risks to these methods.

There are no contraindications to carrying out this type of study except in cases where there is active bronchial bleeding in which taking the sample should be avoided or it should be done with the help of mechanical methods.

What is this study done for?

Sputum analysis is a basic, useful and commonly used tool in the field of Medicine because the technique of obtaining the sample is relatively simple and safe and its analysis by specialized laboratories provides valuable information on the state of the sputum. health of the person. It allows the study, diagnosis and follow-up of multiple inflammatory and / or tumor diseases, both pulmonary and systemic, with pulmonary involvement.

Family and Community Medicine Specialist