• ESPIROMETRIA PRUEBAS RESPIRATORIAS almunecar granada
  • ESPIROMETRIA PRUEBAS RESPIRATORIAS almunecar granada
  • ESPIROMETRIA PRUEBAS RESPIRATORIAS almunecar granada
  • ESPIROMETRIA PRUEBAS RESPIRATORIAS almunecar granada
 

Espirometry

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WHAT IS IT?LA ESPIROMETRÍA es la técnica que mide los flujos y volúmenes respiratorios

SPIROMETRY is the technique which measures the useful respiratory flow and volume for the diagnosis and monitoring of respiratory pathologies.  It can be simple or forced.


Simple spirometry consists in asking the patient, after taking a deep breath in, to expel all the air from their lungs for however long it takes to do so.

The following volumes and capacities are thereby obtained:

    Normal volume: Vt.  Corresponds to the air used for each breath.

    Inspiratory reserve volume: IRV.  Corresponds to the maximum volume inspired after normal volume.

    Expiratory reserve volume: ERV.  Corresponds to the maximum volume exhaled after normal volume.

    Vital capacity:  VC.  Is the total volume mobilised by the lungs, in other words, the sum total of the three afore-mentioned capacities.

    Residual volume: RV.  Is the volume of air that remains after a maximum exhalation.  This cannot be determined with spirometry, it would need to be done using a technique of dilution of gases or corporal plethysmography.

    Total lung capacity: TLC.  Is the sum total of the vital capacity and the residual volume.


ESPIROMETRIA GRANADA Forced spirometry is that in which, after a maximum inhalation, the patient is asked to exhale all the air in the least possible time.  It is more useful than the previous one as it enables us to establish diagnoses of respiratory pathology.

The flow and volume values that most interest us are:

    Forced vital capacity (expressed in millilitres):  Total volume expelled by the patient from the maximum inhalation to the maximum exhalation.  Its normal value is over 80% of the theoretical value.

    Maximum exhaled volume in the first second of forced exhalation (FEV1) (expressed in millilitres):  is the volume expelled in the first second of a forced exhalation.  Its normal value is over 80% of the theoretical.

    Relation FEV1/FVC: indicates the percentage of the total volume exhaled during the first second of the test.  Its normal value is above 70-75%.

    Maximum expiratory flow between 25 and 75% (FEF25-75%): expresses the relation between the volume exhaled, between 25 and 75% of the FVC and the time it takes to do so.  Its alteration may indicate pathology of the small airways.

Its graphic representation is:

ESPIROMETRIA ALMUNECARVolume: (Litres)
Time (Seconds)
Flow (litres/seconds)
Maximum expiratory flow (FEV1)
Forced vital capacity (FVC)
Volume (Litres)

Flow-volume curves:  Establish the values of the FVC and maximum expiratory flow (PEFR or Peak Expiratory Flow Rate).  It facilitates the control of the initial force of the maximum exhalation.

Fig. 3:  Flow-volume curve

Spirometry is carried out for:

    Diagnosis of patients with respiratory symptoms
    Evaluation of pre-operative risk, principally in patients who refer respiratory symptoms
    Evaluation of the pharmaceutical response to specific medication
    Evaluation of certain diseases that affect the lungs

CONTRAINDICATIONS

1.     Absolute:

    Pneumothorax
    Unstable angor
    Detachment of the retina

2.    Relative:

    Tracheotomy
    Facial paralysis
    Buccal problems
    Nauseas provoked by the mouthpiece
    Physical or cognitive deterioration
    Lack of understanding of the steps to be taken

TECHNIQUE:

    Before the test:  explain to the patient the reason for performing the test and remind him or her not to use medication for 6 hours prior to the test in the case of short action bronchodilators and 12 hours for those of prolonged action and delayed action methylxantines.  Nor should the patient smoke or drink caffeine in the hours preceding the test.  The patient should also be advised that during the test he or she will hear energetically delivered orders.

    At the time of taking the test:  the patient will be seated, without tight clothing, a peg will be placed on his or her nose and the mouth will be checked to ensure there are no impediments to the correct insertion of the mouthpiece, and the technician will give an order (Now!) which will indicate the start of the forced exhalation which will take a MINIMUM of 6 seconds, during which the technician will encourage the patient to continue the exhalation, checking that air is expelled continuously and in a constant flow.

    At the end of the test: the spirometry will be complete when 3 technically satisfactory curves have been obtained, which will be those lasting more than 6 seconds and with differences between the FVC and the FEV1 of the three curves below 5% or 100ml.  The maximum number of curves to be carried out will be 8-9.

    Calculation of the best curve:  will be the one with the greater sum total of the FEV1 and the FVC.

    Calculation of the FEV1/FVC quotient:  carried out using the maximum value of the FEV1 and the FVC in any of the technically satisfactory manoeuvres, and which do not need to correspond to one sole graph.