Asnawati Lab. Fisiologi FK Unlam SPIROMETRI Asnawati Lab. Fisiologi FK Unlam

Spirometri Adalah metode penilaian fungsi paru dengan mengukur aliran dan volume udara yang masuk dan meninggalkan paru PFT (test of pulmonary function): Indikator status kesehatan dan penyakit Exercise fitness

Spirometri Metode ini dapat digunakan untuk membedakan gangguan obstruksi jalan napas (misalnya COPD dan asma) dan penyakit restriktif (dimana ukuran paru berkurang, mis. Penyakit paru fibrotic). Spirometri merupakan cara paling efektif untuk menentukan tingkat keparahan COPD  keuntungan utama: dapat mendeteksi COPD sebelum gejala muncul.

Spirometri Kandidat pasien spirometri: Lanjut usia Perokok berat yang berusia di atas 35 tahun Para pekerja yang terpapar iritan respiratori, seperti debu dan asap

KONTRAINDIKASI UNTUK SPIROMETRI Absolut Post operasi dada Bulan2 setelah infark miokardium Instabilitas serius jalan napas – emfisema Hipersensitivitas bronchial non-spesifik Kesulitan serius pertukaran gas – insufisiensi respiratori total atau parsial.

KONTRAINDIKASI UNTUK SPIROMETRI Relatif Kondisi setelah pneumotoraks spontan Aneurisma arterial-venosa. Hipertensi berat Kehamilan dengan komplikasi dalam bulan ketiga. Pro test dalam profil MVV: sindroma hiperventilasi.

Spirometer Alat untuk mengukur volume/kapasitas paru statis dan dinamis menggunakan sistem tertutup Mencatat jumlah dan kecepatan pergerakan udara masuk dan keluar paru.

Kondisi-kondisi yang dapat mempengaruhi hasil pengukuran Nyeri pulmoner atau nyeri perut Nyeri pada mulut atau wajah Inkontinensia tekanan Demensia atau gangguan mental Merokok 1 jam/< sebelum pemeriksaan Konsumsi alcohol 4 jam/< sebelum pemeriksaan Aktivitas yang melelahkan 30 menit/< sebelum pemeriksaan Kekenyangan/makan besar 2 jam/< sebelum pemeriksaan. Pakaian ketat yang dapat mempengaruhi pernapasan maksimal. Kerapian sensor spirometri - selalu pelihara sensor dan pastikan selalu kering dan bersih. Pasang segel silicon antara sensor sprimometer dan pneumotachograph – tanpa ini tidak dapat mengukur kurva atau mengkalibrasi sensor.

Lung Volumes and Capacities 4 volumes: inspiratory reserve volume, tidal volume, expiratory reserve volume, and residual volume 2 or more volumes comprise a capacity. 4 capacites: vital capacity, inspiratory capacity, functional residual capacity, and total lung capacity

Volume dan Kapasitas paru tergantung pada: Usia Ukuran badan (tinggi dan berat) Jenis kelamin Kesehatan paru Ketinggian tempat Bahan iritan

RECOMMENDED TEST SEQUENCE forced spirometry – FVC, PEF relaxed spirometry – SVC, MVV medicine inhalation (if used) repeating of forced spirometry – post-medical examination

Volume udara yang dikeluarkan pada FEV1 sebagian besar merupakan volume udara yang berada pada zona konduksi saluran pernapasan. Saluran pernapasan yang dilewati oleh udara pada pengukuran FEV1 berada antara bronkus sampai bronkiolus terminalis. Pada daerah tersebut terdapat otot polos yang memegang peranan penting dalam pengukuran jumlah udara yang dihasilkan pada FEV1. oleh karena itu FEV1 bisa dijadikan sebagai indikator kontraksi otot polos pada saluran pernapasan tersebut.

Forced Expiratory Vital Capacity Volume yang dikeluarkan setelah subjek menarik napas maksimal kemudian mengekshalasikan secepat dan sekuat mungkin. Mendekati nilai kapasitas vital selama bernapas pelan, kecuali pada pasien dengan penyakit obstruktif dapat lebih rendah (daripada kapasitas vital) How is this done?

Performance of FVC maneuver Check spirometer calibration. Explain test. Prepare patient. Ask about smoking, recent illness, medication use, etc. (adapted from ATS, 1994)

Performance of FVC maneuver (continued) Give instructions and demonstrate: Show nose clip and mouthpiece. Demonstrate position of head with chin slightly elevated and neck somewhat extended. Inhale as much as possible, put mouthpiece in mouth (open circuit), exhale as hard and fast as possible. Give simple instructions. (adapted from ATS, 1994)

Performance of FVC maneuver (continued) Patient performs the maneuver Patient assumes the position Puts nose clip on Inhales maximally Puts mouthpiece on mouth and closes lips around mouthpiece (open circuit) Exhales as hard and fast and long as possible Repeat instructions if necessary –be an effective coach Repeat minimum of three times (check for reproducibility.) (adapted from ATS, 1994)

Flow-Volume Curves and Spirograms Two ways to record results of FVC maneuver: Flow-volume curve---flow meter measures flow rate in L/s upon exhalation; flow plotted as function of volume Classic spirogram---volume as a function of time

Normal Flow-Volume Curve and Spirogram

Spirometry Interpretation: So what constitutes normal? Normal values vary and depend on: Height Age Gender Ethnicity Height varies directly with vc VC increases with age up to age 20 years then becomes inversely proportion to age Women usually with lower vc than men

MAINTAINING ACCURACY The most common reason for inconsistent readings is patient technique. Errors may be detected by observing the patient throughout the manoeuvre and by examining the resultant trace. Common problems include: • inadequate or incomplete inhalation • lack of blast effort during exhalation • additional breath taken during manoeuvre • lips not tight around the mouthpiece • a slow start to the forced exhalation • exhalation stops before complete expiration • some exhalation through the nose • coughing.

Acceptable and Unacceptable Spirograms (from ATS, 1994)

FLOW-VOLUME MEASUREMENT

Measurements Obtained from the FVC Curve FEV1---the volume exhaled during the first second of the FVC maneuver FEF 25-75%---the mean expiratory flow during the middle half of the FVC maneuver; reflects flow through the small (<2 mm in diameter) airways FEV1/FVC---the ratio of FEV1 to FVC X 100 (expressed as a percent); an important value because a reduction of this ratio from expected values is specific for obstructive rather than restrictive diseases

Spirometry can confirm the presence of COPD, even in mild or moderate stages. COPD is characterised by airflow obstruction which does not change markedly over several months. The impairment of lung function is not fully reversed by bronchodilator or other therapy.

How is a flow-volume loop helpful? Helpful in evaluation of air flow limitation on inspiration and expiration In addition to obstructive and restrictive patterns, flow-volume loops can show provide information on upper airway obstruction: Fixed obstruction: constant airflow limitation on inspiration and expiration—such as in tumor, tracheal stenosis Variable extrathoracic obstruction: limitation of inspiratory flow, flattened inspiratory loop—such as in vocal cord dysfunction Variable intrathoracic obstruction: flattening of expiratory limb; as in malignancy or tracheomalacia

Spirometry Pre and Post Bronchodilator Obtain a flow-volume loop. Administer a bronchodilator. Obtain the flow-volume loop again a minimum of 15 minutes after administration of the bronchodilator. Calculate percent change (FEV1 most commonly used---so % change FEV 1= [(FEV1 Post-FEV1 Pre)/FEV1 Pre] X 100). Reversibility is with 12% or greater change.