4. Pneumonia.pptx

Pneumonia Pneumonia or pulmonary inflammation is an inflammation of lung tissue. Causes include infection Bacteria Streptococcus pneumoniae (pneumococcus) Mycoplasma pneumoniae. Viruses Influenza viruses Respiratory syncytial virus (RSV) SARS-CoV-2 (the virus that causes COVID-19) Fungi In more r...

Pneumonia Pneumonia or pulmonary inflammation is an inflammation of lung tissue. Causes include infection Bacteria Streptococcus pneumoniae (pneumococcus) Mycoplasma pneumoniae. Viruses Influenza viruses Respiratory syncytial virus (RSV) SARS-CoV-2 (the virus that causes COVID-19) Fungi In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. The typical bacteria which cause pneumonia are Streptococcus pneumoniae, Staphylococcus aureus, Group A Streptococcus, Klebsiella pneumoniae, Haemophilus influenzae, and gram-negative organisms. These organisms can be easily cultured on standard media or seen on Gram stain, unlike atypical organisms. Atypical organisms Chlamydia pneumoniae Chlamydia psittaci Legionella pneumophila Mycoplasma pneumoniae Epidemiology Epidemiology •Pneumonia is a dangerous condition, and is responsible for many deaths of patients over the age of 80 •Deaths amongst younger populations have dramatically decreased with the advent of antibiotics. •Incidence is 1-3 per 1000 (i.e.. 0.1-03% of people have pneumonia at any one time) •The incidence of bacterial pneumonia amongst those with HIV is higher than in the general population, particularly in IV drug users with HIV. However, the causatory organisms are the same. • Most cases caused by bacteria, about 15% are viral Classification • anatomical location – • if one particular lobe is affected – lobar pneumonia - diffuse : bronchopneumonia • aetiology; e.g. pneumococcal or atypical (e.g. caused by Chlamydia, legionella, coxiella burnetti) • Types : Community acquired Nosocomial Pneumonia can be classified into 2 types based on how the infection is acquired: • Community-acquired pneumonia (CAP): Most common type • Nosocomial pneumonia Hospital-acquired pneumonia (HAP) Ventilator-associated pneumonia (VAP) Healthcare-associated pneumonia (HCAP) HAP develops more than 48 hours after hospital admission. VAP Patients who are mechanically ventilated for more than 48 hours after endotracheal intubation can develop pneumonia known as HCAP occurs in ambulatory patients who are not hospitalized and have had extensive healthcare contact within the last 3 months. Any condition or disease that impairs the host immune response, for example, older age (older than 65 years), immunosuppression, diabetes, lung cancer, chronic lung disease CKD Conditions which increase the risk of macro- or micro-aspiration include stroke, seizures, anesthesia, drug intoxication. Cigarette smoking, alcoholism, malnutrition, o obstruction of bronchi from tumors are other common predisposing conditions. Pathophysiology? Congestion/consolidation in the first 24 hours in which the lungs are heavy, red, and, boggy. Microscopically characterized by vascular engorgement and intra-alveolar edema. Many bacteria and few neutrophils are present. Red hepatization/early consolidation begins 2 to 3 days after consolidation and lasts for 2 to 4 days and named because of firm liver-like consistency. The affected lung is red-pink, dry, granular and, airless. Fibrin strands replace the edema fluid of the previous phase. Microscopically marked cellular exudate of neutrophils with some showing ingested bacteria, extravasation of erythrocytes, desquamated epithelial cells, and fibrin within the alveoli are Grey hepatization/late consolidation occurs 2 to 3 days following red hepatization and lasts for 4 to 8 days. The lung appears gray with liver-like consistency due to fibrinopurulent exudate, progressive disintegration of red blood cells, and hemosiderin. The macrophages begin to appear. Resolution and restoration of the pulmonary architecture start by the eighth day. The enzymatic action begins centrally and spreads peripherally which liquefies the previous Symptoms •Typically the same for hospital acquired / non-hospital acquired cases •Shortness of breath •Cough • May be productive in adolescents and adults – Purulent sputum possible • Often dry in infants and the elderly •Fever Rigors •Pleuritic chest pain – which may on occasion radiate to the shoulder (if diaphragm is involved) or the anterior abdominal wall most painful on inspiration •Loss of appetite •Very occasionally – haemoptysis . HeadacheVomiting Appearance of the Patient •Patients with pneumonia usually appear normal or in distress. Vital Signs •Decreased oxygen saturation •Fever •Hypotension < 90 mm Hg •Tachycardia > 125 beats/min •Tachypnea •Examination of respiratory system •Palpation Decrease chest mvmt / Increased tactile fremitus •Percussion Dullness on percussion •Auscultation Bronchial breath sounds Crackles, Rales Investigations Diagnosis SPO2/ABG Oxygen saturation – <92% is worrying CXR Usually an x-ray is performed after clinical suspicion to confirm the diagnosis. The x-ray may show: Evidence of infiltrate in the form of consolidation on the x-ray – can also show the spread of any infection by distribution of the infiltrate Changes may not appear on x-ray for up to 48 hours after symptoms, however, after effective treatment, consolidation may still be seen on x-ray for up to 6 weeks Persistent x-ray changes may suggest underlying carcinoma with secondary • FBC ↑WBC ↑ESR (>100mm/h) and ↑CRP Possible anaemia (sign of abscess) Sputumculture/Gram’s stain Blood cultures – in ill patients to check for septicaemia Urine – in severe cases of pneumonia, where legionella is suspected, urine testing for legionella antigen may be indicated • Renal function- Bld urea/Se creatinine • • • • • • The CURB-65 score – is a scale used to assess the severity of community-acquired pneumonia. It predicts the risk of mortality (CURB score 0 = <1% risk, CURB score 5= 60% risk). Each factor of the score is worth 1 point. C – Confusion – use the abbreviated mental test (score ≤8) U – Urea – >7mmol/L Respiratory rate – ≥30/min Blood Pressure <90 systolic, or <60 diastolic 65 – age >65 years A score ≥3 is severe pneumonia. ≥2 requires hospitalisation. Differentials Pulmonary embolism (PE) – patient is not usually systemically unwell. Shortness of breath is more likely to be sudden onset. Pulmonary / pleural TB Pulmonary oedema Treatment If not vomiting, and CURB65 score ≤2, oral antibiotics.- Amoxycillin /erythromycin( macrolide) If severe and/or vomiting, IV antibiotics required, as per sensitivities. Keep Oxygen saturation >92%, using oxygen therapy as required IV fluids, to prevent dehydration and shock Monitor progress – All patients should receive 6 week follow-up including repeat CXR • Outpatient monotherapy with macrolides, such as azithromycin and clarithromycin are the first choice newer fluoroquinolones like levofloxacin, moxifloxacin,/ amoxycillin • Inpatient non-ICU management: The recommended therapy includes newer fluoroquinolones alone or a combination of beta-lactam/second or third-generation cephalosporin r and a macrolide • Or amoxycillin and macrolide • Inpatient ICU management: The recommended therapy is a combination of macrolide/newer fluoroquinolone and a beta-lactam. Complications • • • • • • • Respiratory failure Septicaemic shock Atrial Fibrillation Pleural Effusion Empyema Lung collapse Lung abscess A 50 year old patient presents with SOB. • Accumulation of fluid within the visceral and parietal layers of the pleura when there is an imbalance between formation and absorption in various disease states. • Normal amount 8.4 ml per hemi thorax Five types of fluids can accumulate in the pleural space: Serous fluid (hydrothorax) Blood (hemothorax) Chyle (chylothorax) Pus (pyothorax or empyema) Urine (urinothorax) History: EVALUATION • Dyspnea Physical Examination • Pleuritic chest pain • Decrease chest expansion • Cough & Fever • Dullness to percussion • Hemoptysis • Decreased breath sounds • Weight loss • Absent tactile fremitus • Trauma • Other findings: • History of cancer • ascites, JVP, peripheral • smoking edema, unilateral leg • Cardiac surgery swelling Pleural Effusion Chest X-Ray PA view Lateral decubitus Thoracentesis., Contraindications None absolute. Relative include • Patient on anticoagulation or with bleeding diathesis • Very small volume of fluid. • Patients are mechanical ventilation though not at increased risk for pneumothorax are at high risk for tension pneumothorax or persistent airleak. • Active skin infection at the port of entry. SAFE TRIANGLE CLUES TO THE COMMON ETIOLOGIES • Distended neck veins, S3 gallop, peripheral edema suggests congestive heart failure. • A right ventricular heave or thrombophlebitis/DVT and sinus tachycardia suggests pulmonary embolus. • The presence of lymphadenopathy or hepatomegaly suggests neoplastic disease. • .Signs of consolidation above the level of the fluid in a febrile patient suggests para pneumonic effusion. • Ascites may suggest a hepatic cause Chest tube drainage with under water seal PLEURAL FLUID ANALYSIS Appearance • Bloody Hct<1% not significant, 1-20%= Cancer, PE, • Trauma >50% serum Hct = hemothorax • Cloudy trig level >110mg/dl = chylothorax • Putrid odor : stain and culture = infection? • Straw coloured - ?? PTB Transudate vs Exudate? On the basis of fluid present - Exudative pleural effusion Transudative pleural effusion Exudates Vs transudates Light’s criteria • Pleural fluid protein/serum protein >0.5 • Pleural fluid LDH/serum LDH >0.6 • Pleural fluid LDH more than two-thirds normal upper limit for serum Transudative Pleural effusions • • • • • • • Congestive heart failure Cirrhosis Pulmonary embolism Nephrotic syndrome Peritoneal dialysis Superior vena cava obstruction Myxedema Exudative Pleural Effusions • • • • • • • Neoplastic diseases Infectious diseases Pulmonary embolization Gastrointestinal disease Collagen-vascular diseases miscellaneous Drug-induced pleural disease Total and Differential Cell Counts • Predominance of neutrophils in the fluid >50% indicates that an acute process is affecting the pleura. Common causes include – parapneumonic effusions (81 percent), – effusions secondary to pulmonary embolus (80 percent), and – those secondary to pancreatitis(80 percent). – Mononuclear cells like small lymphocytes >50% indicates a chronic process. – cancer or tuberculous pleuritis, Imaging contd., Role of CT scan /MRI – can display pleural effusions, pleural tumors, and chest wall invasion. – can characterize the content of pleural effusions. – Can determine the age of the hemorrhage. Fluid Tests for Cancer – Cytology is a fast, efficient, and minimally invasive – not routinely warranted in young patients with evidence of acute illness. – establishes the diagnosis in more than 70 percent of cases of metastatic adenocarcinoma – less efficient - diagnosis of a mesothelioma squamous cell carcinoma, – lymphoma or a sarcoma. – If cytology is negative – go for thoracoscopy & biopsy Markers of Tuberculosis • warranted if there is pleural fluid lymphocytosis. • < 40 % have positive cultures, hence alternative means are used. – adenosine deaminase (>40 U/L) (99.6% sensitive and 97.1 % specific)) or – the PCR for mycobacterial DNA – definitive for TB. Evaluation for Pulmonary Embolism – Always consider if pleuritic chest pain, hemoptysis, or dyspnea out of proportion to the size of theeffusion. – D-dimer in the peripheral blood is the best screening test . – If a sensitive D-dimer test is used and it is negative, the diagnosis of pulmonary embolism is essentially ruled out. – If the D-dimer test is positive, then additional specific diagnostic testing — such as duplex ultrasonography of the legs, spiral CT, perfusion scanning of the lungs, or pulmonary arteriography — is necessary to establish the diagnosis. The undiagnosed effusion. – No known etiology found in a substantial percentage of patients with exudative effusions – If the effusion persists despite conservative treatment, thoracoscopy should be considered, since it has a high yield for cancer or tuberculosis. – If thoracoscopy is unavailable, alternative invasive approaches are needle biopsy and open biopsy of the pleura. – No diagnosis is ever established for approximately 15 percent of patients despite invasive procedures. Health care associated pneumonia (HCAP) A is defined as pneumonia that occurs 48 hours or more after hospital admission B pneumonia in ventilated patients C acquired in community D occurs in ambulatory patients who are not hospitalized and have had extensive healthcare contact within the last 3 months. Which of the following refers to a milky white effusion high in triglycerides? A.Chyliform effusion B.Chylous effusion C.Hemothorax D.Trapped lung