380 likes | 1.22k Views
30/07/2000. DR.T.M.K- ARDS. 2. DIAGNOSTIC CRITERIA. ARDSAcutePaO2/Fio2<200 mmHgBilateral interstitialor alveolar infiltratesPcwp <15-18 mmHg. ALIAcute<300 mm HgSamesame. 30/07/2000. DR.T.M.K- ARDS. 3. Clinical diagnosis. RapidWithin 12 to 48 hr of the predisposing eventAwake patients be
E N D
1. ARDS DR. T. MOHAN KUMAR, MD, AB, DPPR, FCCP
CHIEF & SENIOR CONSULTANT,
DEPARTMENT OF PULMONOLOGY & CRITICAL CARE,
SRI RAMAKRISHNA HOSPITAL,
COIMBATORE ARDS IS A CLINICAL SYNDROME CHARACTERIZED BY ACUTE RESPIRATOR DISTRESS,REFRACTORY HYPOXEMIA,DECREASED RESPIRATORY SYSTEM COMPLIANCE AND DIFFUSE PULMONARY INFILTRATESON THE CHEST RADIOGRAPHARDS IS A CLINICAL SYNDROME CHARACTERIZED BY ACUTE RESPIRATOR DISTRESS,REFRACTORY HYPOXEMIA,DECREASED RESPIRATORY SYSTEM COMPLIANCE AND DIFFUSE PULMONARY INFILTRATESON THE CHEST RADIOGRAPH
2. 30/07/2000 DR.T.M.K- ARDS 2 DIAGNOSTIC CRITERIA ARDS
Acute
PaO2/Fio2<200 mmHg
Bilateral interstitial
or alveolar infiltrates
Pcwp <15-18 mmHg ALI
Acute
<300 mm Hg
Same
same
3. 30/07/2000 DR.T.M.K- ARDS 3 Clinical diagnosis Rapid
Within 12 to 48 hr of the predisposing event
Awake patients become anxious,agitated &
dyspnoeic
Dyspnoea on exertion proceeding to severe when hypoxemia intervenes
Stiffening of lung leads to increase work of breathing,small tidal volumes,rapid respiratory rate
Initially respiratory alkalosis
Respiratory failure
4. 30/07/2000 DR.T.M.K- ARDS 4 Clinical disorders associated with ARDS Direct lung injury
Aspiration of gastric contents
Pulmonary contusion
Toxic gas inhalation
Near drowning
Diffuse pulmonary infection Indirect lung injury
Severe sepsis
Major trauma
Hypertransfusion
Acute pancreatitis
Drug overdose
Reperfusion injury
Post cardiac bypass/lung transplants
5. 30/07/2000 DR.T.M.K- ARDS 5 Clinical disorders associated with ARDS FREQUENT CAUSES
SEPSIS
BACTEREMIA WITHOUT SEPSIS SYNDROME 4%
SEVERE SEPSIS/SEPSIS SYNDROME 35-45%
MAJOR TRAUMA
MULTIPLE BONE FRACTURES 5-10%
PULMONARY CONTUSION 17-22%
HYPERTRANSFUSION 5-36%
ASPIRATION OF GASTRIC CONTENTS 22-36%
6. 30/07/2000 DR.T.M.K- ARDS 6 CLINICAL MANIFESTATIONS ARDS occurs in the setting of acute severe illness
Clinical manifestations may vary
Sepsis and trauma most important
Multiple organ failure
Atelectasis and fluid filled lungs
Hypoxemia/dyspnoea
Fever /leukocytosis
7. 30/07/2000 DR.T.M.K- ARDS 7 Laboratory studies To date no lab findings pathognomonic of ARDS
X-ray chest shows bilateral infiltrates consistent with pulmonary edema, may be mild or dense, interstitial or alveolar, patchy or confluent
ABG shows hypoxemia with respiratory alkalosis. In late stages hypoxemia, acidosis, hypercarbia may be seen.
8. 30/07/2000 DR.T.M.K- ARDS 8 Leukocytosis/Leukopenia/anemia are common
Renal function abnormalities/or liver function
Von willebrands factor or complement in serum may be high
Acute phase reactants like ceruloplasmin or cytokine (TNF,IL-1,IL-6,IL-8) may be high.
9. 30/07/2000 DR.T.M.K- ARDS 9 BRONCHOALVEOLAR LAVAGE Inflammatory mediators like cytokines, reactive oxygen species, leukotrienes & activated complement fragments are found in the fluid
Cellular analysis shows more than 60% of neutrophils.
As ARDS resolves neutrophils are replaced with alveolar macrophages.
Another interesting finding is the presence of a marker of pulmonary fibrosis called procollagen peptide III (PCPIII) and this correlates with mortality.
Presence of more eosinophils suggest eosinophilic pneumonia, high lymphocyte counts may be seen in hypersensitivity pneumonitis, sarcoidosis, BOOP, or other acute forms of interstitial lung disease.
10. 30/07/2000 DR.T.M.K- ARDS 10 Differential diagnosis Infectious causes
Bacteria - Gm neg & pos , mycobacteriae, mycoplasma, rickettsia, chlamydia
Viruses- CMV, RSV, hanta virus, adeno virus, influenza virus
Fungi- H.capsulatum, C.immitis
parasites- pneumocytis carinii, toxoplasma gondii
11. 30/07/2000 DR.T.M.K- ARDS 11 Differential Diagnosis Non infectious causes
CCF
Drugs & toxins (paraquat, aspirin, heroin, narcotics, toxic gas, tricyclic anti depressants, acute radiation pneumonitis)
Idiopathic (esinophilic pneumonia, Acute interstitial pneumonitis, BOOP, sarcoidosis, rapidly involving idiopathic pulmonary fibrosis)
Immunologic (acute lupus pneumonitis, Good Pastures syndrome, hypersensitivity pneumonitis)
Metabolic (alveolar proteinosis)
Miscellaneous (fat embolism, neuro/high altitude pulmonary oedema)
Neoplastic (leukemic infiltration, lymphoma)
12. 30/07/2000 DR.T.M.K- ARDS 12 Therapy -goals Treatment of the underlying precipitating event
Cardio-respiratory support
Specific therapies targeted at the lung injury
Supportive therapies
13. Respiratory Support
14. 30/07/2000 DR.T.M.K- ARDS 14 Spontaneously Breathing Patient In the early stages of ARDS the hypoxia may be corrected by 40 to 60% inspired oxygen with CPAP Peak inspiratory flow rates of >= 70ltrs / min require a tight-fitting face mask with a large reservoir bag or a high flow generator If the patient is well oxygenated on <= 60 % inspired oxygen and apparently stable without CO2 retention and apparently stable, then ward monitoring may be feasible but close observation( 15 to 30 Min), continuous oximetry, and regular blood gases are required