Parameter pemantauan penyakit saluran nafas

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1 Parameter pemantauan penyakit saluran nafas Uji fungsi paru Analisis gas darah 2010/10/23 Zullies Ikawati's Lecture Notes 1 Uji Fungsi Paru-paru (lung function test) Peak flow meter Spirometer 2010/10/23 Zullies Ikawati's Lecture Notes 2 1

2 Lung Function Test Untuk mendiagnosis gangguan paru-paru dan seberapa parah gangguan tersebut t Beberapa macam test : - spirometry rutin - gas diffusion test - body yplethysmography, p y, dll. Lung diffusion testing measures how well oxygen passes from the air sacs in the lungs into the blood 2010/10/23 3 Body plethysmography a very sensitive lung measurement used to detect lung pathology that might be missed with conventional pulmonary function tests. This method of obtaining the absolute volume of air within one's lungs may also be used in situations where several repeated trials are required or where the patient is unable to perform the multibreath tests. 2010/10/23 Zullies Ikawati's Lecture Notes 4 2

3 Spirometri 2010/10/23 Zullies Ikawati's Lecture Notes 5 Peak flow meter PEF = Peak Expiratory Flow Peak flow meter sering digunakan oleh pasien asma untuk mengukur jumlah udara yang dapat dihembuskan dari paru-paru. Jika saluran nafas menyempit atau tersumbat karena asma, nilai peak flow akan menurun karena pasien tidak dapat menghembuskan udara dengan sempurna. Peak flow meter berguna untuk memonitor pasien asma sepanjang waktu dan dapat untuk menentukan apakah pengobatan asma berhasil atau tidak. 2010/10/23 Zullies Ikawati's Lecture Notes 6 3

4 Kapasitas dan volume statis paru 2010/10/23 Zullies Ikawati's Lecture Notes 7 Volume statis paru-paru Volume tidal (VT) = jumlah udara yang dihirup dan dihembuskan setiap kali bernafas pada saat istirahat. Volume tidal normal bagi ml. Volume residu (RV) = jumlah gas yang tersisa di paru-paru setelah menghembuskan nafas secara maksimal atau ekspirasi paksa. Nilai normalnya adalah 1200 ml. Kapasitas vital (VC) = jumlah gas yang dapat diekspirasi setelah inspirasi secara maksimal. VC = VT + IRV + ERV (seharusnya 80 % TLC) Besarnya adalah 4800 ml. Kapasitas total paru-paru (TLC) = yaitu jumlah total udara yang dapat dimasukkan ke dlm paru-paru setelah inspirasi maksimal. TLC = VT + IRV + ERV + RV. Besarnya adalah 6000 ml. 2010/10/23 Zullies Ikawati's Lecture Notes 8 4

5 Kapasitas residu fungsional (FRC) = jumlah gas yang tertinggal di paru-paru setelah ekspirasi volume tidal normal. FRC = ERV + RV. Besarnya berkisar 2400 ml. Kapasitas inspirasi i i (IC) = jumlah udara maksimal yang dapat diinspirasi setelah ekspirasi normal. IC = VT + IRV. Nilai normalnya sekitar 3600 ml. Volume cadangan inspirasi (IRV) = jumlah udara yang dapat diinspirasi secara paksa sesudah inspirasi volume tidal normal Volume cadangan ekspirasi (ERV) = jumlah udara yang dapat diekspirasi secara paksa sesudah ekspirasi volume tidal normal 2010/10/23 Zullies Ikawati's Lecture Notes 9 Volume dinamis paru-paru Parameter: FVC, FEV 1 menentukan fungsi paru FVC : Forced Vital Capacity Volume udara maksimum yang dapat dihembuskan secara paksa kapasitas vital paksa Umumnya dicapai dalam 3 detik Normalnya: 4 liter FEV 1 : Forced Expired Volume in one second Volume udara yang dapat dihembuskan paksa pada satu detik pertama Normalnya 3,2 liter Orang sehat dapat menghembuskan 75-80% atau lebih FVC-nya dalam satu detik rasio FEV 1 /FVC = 75-80% 2010/10/23 Zullies Ikawati's Lecture Notes 10 5

6 Spirogram normal yang menunjukkan FVC, FEV1, dan FEF 25-75% 2010/10/23 Zullies Ikawati's Lecture Notes 11 Basic of Pulmonary Function Test Obstructive Lung Disease = tidak dapat menghembuskan udara (unable to get air out) - FEV 1 /FVC < 75% Semakin rendah rasionya, semakin parah obstruksinya FEV 1 : 60-75% = mild FEV 1 : 40-59% = moderate FEV 1 : <40% = severe Restrictive Lung Disease = tidak dapat menarik napas (unable to get air in) FVC rendah; FEV 1 /FVC normal atau meningkat TLC berkurang sebagai Gold Standard 2010/10/23 Zullies Ikawati's Lecture Notes 12 6

7 Obstructive Jalan nafas yang menyempit akan mengurangi voulume udara yang dapat dihembuskan pada satu detik pertama ekspirasi. Amati bahwa FVC hanya dapat dicapai setelah ekshalasi yang panjang. Rasio FEV1/FVC berkurang secara nyata. Ekspirasi diperlama dgn peningkatan perlahan pada kurva, dan plateau tidak tercapai sampai waktu 15 detik. Restrictive FEV1 dan FVC menurun. Karena jalan nafas tetap terbuka, ekspirasi bisa cepat dan selesai dlm waktu 2-3 detik. Rasio FEV1/FVC tetap normal atau malah meningkat, tetapi volume udara yang terhirup dan terhembus lebih kecil dibandingkan normal. Mixed Ekspirasi diperlama dengan peningkatan kurva perlahan mencapai plateau. Kapasitas vital berkurang signifikan dibandingkan gangguan obstruktif. Pola campuran ini, jika tidak terlalu parah, sulit dibedakan dengan pola obstruktif. 2010/10/23 Zullies Ikawati's Lecture Notes 13 Blood gases analysis Definition Blood gases is a measurement of how much oxygen and carbon dioxide is in your blood. It also determines the acidity (ph) of your blood. Why is the Test Performed? The test is used to evaluate respiratory diseases and conditions that affect the lungs. It helps determine the effectiveness of oxygen therapy. The test also provides information about the body's acid/base balance, which can reveal important clues about lung and kidney function and the body's general metabolic state. 2010/10/23 Zullies Ikawati's Lecture Notes 14 7

8 Blood gases test/analysis The blood gases test is performed by collecting a sample of bloodthrough a needle from an artery. The test is used to evaluate respiratory diseases and conditions that affect the lungs, and it is used to determine the effectiveness of oxygen therapy. The acid base component of the test also gives information on how well the kidneys are functioning. 2010/10/23 Zullies Ikawati's Lecture Notes 15 Nilai-nilai normal gas-gas darah Pengukuran gas darah Simbol Nilai normal Tekanan karbon dioksida PaCO mmhg (rata rata 40) > 45 mmhg : hipoventilasi < 35 mmhg : hiperventilasi Tekanan oksigen PaO mm Hg mmhg : hipoksemia ringan mmhg : hipoksemia sedang < 40 mmhg : hipoksemia berat Persentasi kejenuhan SaO % oksigen Konsentrasi ion hidrogen ph 7,35 7,45 Bikarbonat HCO meq/l 2010/10/23 Zullies Ikawati's Lecture Notes 16 8

9 Perubahan asam-basa pada asidosis dan alkalosis Gangguan asam-basa ph HCO - 3 PCO 2 Asidosis respiratorik Alkalosis respiratorik Asidosis metabolic Alkalosis metabolik 2010/10/23 Zullies Ikawati's Lecture Notes 17 Respiratory acidosis Respiratory acidosis is a condition that occurs when the lungs cannot remove all of the carbon dioxide the body produces. This disrupts the body's acid base balance causing body fluids, especially the blood, to become too acidic Chronic respiratory acidosis occurs over a long period of time. This leads to a stable situation, because the kidneys increase body chemicals, such as bicarbonate, that help restore the body's acid base balance. Acute respiratory acidosis is a severe condition in which carbon dioxide builds up very quickly and before the kidneys can return the body to a state of balance. 2010/10/23 Zullies Ikawati's Lecture Notes 18 9

10 Causes of respiratory acidosis include: Diseases of the airways (such as asthma and chronic obstructive lung disease), which send air into and out of the lungs Diseases of the chest (such as scoliosis), which make the lungs less efficient at filling and emptying Diseases affecting the nerves and muscles that "signal" the lungs to inflate or deflate Drugs that suppress breathing (including powerful pain medicines, such as narcotics, and "downers downers, " such as benzodiazepines), especially when combined with alcohol Severe obesity, which restricts how much the lungs can expand 2010/10/23 Zullies Ikawati's Lecture Notes 19 Respiratory alkalosis Definition Respiratory alkalosis is a condition marked by low levels of carbon dioxide in the blood due to breathing excessively. Common causes include: Anxiety Fever Hyperventilation Any lung disease that leads to shortness of breath can also cause respiratory alkalosis. 2010/10/23 Zullies Ikawati's Lecture Notes 20 10

11 Metabolic acidosis Definition Metabolic acidosis is a condition in which there is too much acid in the body fluids. Metabolic acidosis occurs when the body produces too much acid, or when the kidneys are not removing enough acid from the body. There are several types of metablic acidosis: Diabetic acidosis (also called diabetic ketoacidosis and DKA) develops when substances known as ketone bodies, which are acidic, build up during uncontrolled diabetes Hyperchloremic acidosis results from excessive loss of sodium bicarbonate from the body, as can happen with severe diarrhea Lactic acidosis is a buildup of lactic acid. 2010/10/23 Zullies Ikawati's Lecture Notes 21 11