Pneumonia (PDF)

Pneumonia By Dr. Haitham Nabeel Your Date Here Your Footer Here  Pneumonia Your Date Here Your Footer Here Definition Pneumonia is as an acute respiratory illness associated with recently developed radiological pulmonary shad...

Pneumonia By Dr. Haitham Nabeel Your Date Here Your Footer Here  Pneumonia Your Date Here Your Footer Here Definition Pneumonia is as an acute respiratory illness associated with recently developed radiological pulmonary shadowing, which may be segmental, lobar or multilobar. ‫الزم اكو شادونك حته اميزها مثال ع البرونكياكتسس‬ Your Date Here Your Footer Here 3 Classification of pneumonia 1-Community-acquired pneumonia Typical pneumonia Atypical pneumonia Streptococcus pneumoniae (most common) Bacteria Also the most common pathogen in nursing Mycoplasma pneumoniae (most common in the ambulatory setting) home residents Chlamydophila pneumoniae Calm my leg Most common cause of pneumonia in injection Chlamydophila psittaci drug users Legionella pneumophila → legionellosis Haemophilus influenzae Coxiella burnetii → Q fever Moraxella catarrhalis Francisella tularensis → tularemia Klebsiella pneumoniae‫غالبا ب الكهولزم‬ Viruses Staphylococcus aureus RSV Influenza viruses, Parainfluenza viruses COPD ‫ انفكشنات هن نفسهن اليسبنب اكزاسيربريشن ل‬٣ ‫الحظ ان اول‬ CMV Cytomegalovirus Adenovirus Coronaviridae (e.g., SARS-CoV-2) 4 Classification of pneumonia 2-Hospital-acquired pneumonia Gram-negative pathogens Pseudomonas aeruginosa Enterobacteriaceae Acinetobacter spp Staphylococci (Staphylococcus aureus) Streptococcus pneumoniae Your Date Here Your Footer Here 5 Classification of pneumonia 1-Lobar pneumonia Most common: S. pneumoniae Less common Legionella Klebsiella H. influenzae Your Date Here Your Footer Here 6 Classification of pneumonia 2-Bronchopneumonia S. pneumoniae S. aureus H. influenzae Klebsiella Diffused patches Your Date Here Your Footer Here 7  Classification of pneumonia Reticulonodular 3-Interstitial pneumonia Atypical pathogens Mycoplasma pneumoniae Calm my leg Chlamydophila pneumoniae Chlamydophila psittaci Legionella Viruses (e.g., RSV, CMV, influenza, adenovirus) Coxiella burnetii Q-fever Your Date Here Your Footer Here 8 Risk factors Cigarette smoking Old age Upper respiratory tract Recent influenza Infections infection Alcohol Pre-existing lung disease Corticosteroid therapy HIV Indoor air pollution Legionella ‫ﺧﺼﻮﺻﺎ ب‬ Your Date Here Your Footer Here 9 Pathophysiology Routes of infection Most common: microaspiration (droplet infection) of airborne pathogens or oropharyngeal secretions Aspiration of gastric acid (aspiration pneumonitis) , food, or liquids Hematogenous dissemination ‫تجي من الدم‬ (rare) Your Date Here Your Footer Here 10 Pathophysiology Pathogenesis Failure of protective pulmonary mechanisms (e.g., cough reflex , mucociliary clearance , alveolar macrophages ) Infiltration of the pulmonary parenchyma by the pathogen → interstitial and alveolar inflammation Impaired alveolar ventilation → ventilation/perfusion (V/Q) mismatch with intrapulmonary shunting (right to left) ‫اﻟﺪم ﺳﺪﺧﻞ دﯾﺎوﻛﺴﺠﯿﻨﯿﺘﺪ وﯾﻄﻠﻊ‬ Hypoxia due to increased alveolar-arterial oxygen gradient ‫دﯾﺎوﻛﺴﺠﯿﻨﯿﺘﺪد‬ Hypoxia is worsened when the affected lung is in the dependent position, as perfusion to the dependent lung is better compared to the nondependent lung. Your Date Here Your Footer Here 11 Clinical features Typical pneumonia Typical pneumonia is characterized by a sudden onset of symptoms caused by lobar infiltration. Severe malaise High fever and chills Productive cough with purulent sputum (yellow-greenish) Crackles and bronchial breath sounds on auscultation Decreased breath sounds Enhanced bronchophony, egophony, and tactile fremitus Dullness on percussion Tachypnea and dyspnea (nasal flaring, thoracic retractions) ‫ ﻓﺘﺤﺔ اﻻﻧﻒ اﻟﺨﺎرﺟﺔ ﺗﻜﺒﺮ وي ﻛﻞ اﻧﺴﺒﺎﯾﺮﯾﺸﻦ‬+ ‫ﯾﺴﺘﺨﺪم اﻻﻛﺴﻠﺮي ﻣﺼﻞ‬ Pleuritic chest pain when breathing, often accompanying pleural effusion Pain that radiates to the abdomen and epigastric region (particularly in children) Your Date Here Your Footer Here 12 Clinical features Atypical pneumonia Typically has an indolent course (slow onset) and commonly manifests with extrapulmonary symptoms. Nonproductive, dry cough Dyspnea Auscultation often unremarkable Common extrapulmonary features include fatigue, headaches, sore throat, myalgias, and malaise. Your Date Here Your Footer Here 13  This classification does not have a major impact on patient management because it is not always possible to clearly distinguish between typical and atypical pneumonia. Clinical pearl! Your Date Here Your Footer Here 14 Hints to the etiology! Rust-coloured sputum in streptococcal pneumonia ‫ زﻧﺠﺎ ر‬، ‫ﺻﺪى‬ Your Date Here Your Footer Here 15 Hints to the etiology! ‫مشمشي‬ ‫جلي‬ Alcoholic patient presenting with currant-jelly sputum think of klebsiella Alcoholic Your Date Here Your Footer Here 16 Hints to the etiology! Pneumonia after influenza, think of staph. Aureus Your Date Here Your Footer Here 17 Hints to the etiology! In presence of skin pustules, also think of staph. Aureus Your Date Here Your Footer Here 18 Hints to the etiology! Pneumonia in a patient with COPD, think of H. Influenzae Your Date Here Your Footer Here 19 Hints to the etiology! Bad dental hygiene, think of Klebsiella or Actinomyces israelii. Your Date Here Your Footer Here 20 Hints to the etiology! In presence of herpes labialis, think of streptococal infection. Your Date Here Your Footer Here 21 Diagnostics Pneumonia is a clinical diagnosis based on history, physical examination, laboratory findings, and CXR findings. Consider microbiological studies and advanced diagnostics based on patient history, comorbidities, severity, and entity of pneumonia Aim of investigations: Confirm the diagnosis Exclude other conditions Assess the severity Identify the development of complications Your Date Here Your Footer Here 22 Laboratory studies Complete Blood Count (CBC): High WBC count ( leukocytosis) Neutrophil leucocytosis =bacterial aetiology WBC Very high or low = marker of severity Haemolytic anaemia think of Mycoplasma Inflammatory markers: ↑ CRP, ↑ ESR Inflammatory parameters are often unremarkable in atypical pneumonia. Your Date Here Your Footer Here 23 Laboratory studies Urea and electrolytes Urea > (~20 mg/dL): marker of severity Hyponatraemia = marker of severity Liver function tests Abnormal if basal pneumonia inflames liver Hypoalbuminaemia = marker of severity ‫ الن املخزون مل البومني باللفر يبني النقص بي ورا اسبوع تقريبا‬، ‫مو نتيجة ل تدمير باللفر‬ ‫ يصعد باالنفكشن ف االلبومني ينزل باالنفكشن وكلما نزل اكثر يعني‬cpr ‫يعني مثل ما‬، ‫انما هذا رح نعتبرة من دالالت االنفكشن‬ ‫السفرتي اكثر‬ Your Date Here Your Footer Here 24 Microbiological studies Blood culture Bacteraemia: marker of severity Sputum samples for Gram stain and culture Oropharynx swab ‫اﻛﺸﻒ اﻻورﻛﺎﻧﺰم ﻣﻦ اﻟﺤﻤﺾ اﻟﻨﻮوي ﻣﺎﻟﺘﮫ‬ PCR for Mycoplasma pneumoniae and other atypical pathogens Urine for pneumococcal and Legionella Ag Your Date Here Your Footer Here 25 Imaging Chest x-ray (posteroanterior and lateral) Indications: all patients suspected of having pneumonia Findings Lobar pneumonia Opacity of one or more pulmonary lobes Presence of air bronchograms: appearance of translucent bronchi inside opaque areas of alveolar consolidation Bronchopneumonia Nodolar pnemoneia Poorly defined patchy infiltrates scattered throughout the lungs Presence of air bronchograms Atypical or interstitial pneumonia Diffuse reticular opacity Absent (or minimal) consolidation Parapneumonic effusion Your Date Here Your Footer Here 26 Left upper lobe pneumonia Chest x-ray (PA view) A large, homogeneous opacification (green overlay) can be seen over the left upper lobe. It is also obscuring the left heart border and left pulmonary vessels. This appearance is typical of airspace consolidation due to left upper lobe pneumonia. Your Date Here Your Footer Here 27 Bronchopneumonia Chest x-ray (AP view) There are poorly defined patchy infiltrates (green overlay), mainly affecting the left middle and upper bronchi and bronchioles. ECG electrodes and cables can also be seen. These findings are typical of bronchopneumonia. Your Date Here Your Footer Here 28 Atypical pneumonia X-ray chest (PA view) There are prominent vascular markings seen around both hilum and lower lobes. There is a heterogeneous, unilateral opacity in the right middle and lower lung field (green overlay). These findings are characteristic of lobar consolidation due to pneumonia. Your Date Here Your Footer Here 29  A new pulmonary infiltrate on chest x- ray in a patient with classic symptoms of pneumonia confirms the diagnosis. Clinical pearl! Your Date Here Your Footer Here 30 Imaging Chest CT (usually without contrast) Indications Inconclusive chest x-ray Recurrent pneumonia Poor response to treatment Advantages: more reliable evaluation of circumscribed opacities, pleural empyema, or sites of consolidation Findings: Localized areas of consolidation (hyperdense) Air bronchograms Ground-glass opacities Pleural effusion/empyema Your Date Here Your Footer Here 31 Bronchopneumonia X-ray chest (PA view) and CT chest (axial view) There are poorly defined patchy infiltrates (green overlay), widely disseminated throughout both lungs. These findings are characteristic of bronchopneumonia. Your Date Here Your Footer Here 32 Treatment Approach Assess the need for hospitalization with the CURB-65 score. Determine the appropriate level of care using clinical judgment. Begin empiric antibiotic therapy based on severity and patient risk factors (e.g., VAP vs CAP). Provide supportive care. Re-evaluate therapy after 48 hours (earlier if the patient's condition deteriorates or new information becomes available). Your Date Here Your Footer Here 33 CURB-65 score ‫ﯾﺮﺟﻌﻠﻚ ﺑﯿﻦ ﻓﺘﺮة وﻓﺘﺮة‬ Your Date Here Your Footer Here 34 Level of care Indication for ICU admission CURB score of 4–5, failing to respond rapidly to initial management empiric therapy Persisting hypoxia PaO2 ≤60 mmHg, despite high concentrations of oxygen Progressive hypercapnia Severe acidosis Circulatory shock Reduced conscious level Your Date Here Your Footer Here 35 Antibiotics Prompt administration of antibiotics improves the outcome. The initial choice of antibiotic is guided by clinical context, Causative agent Severity assessment, local knowledge of antibiotic resistance patterns and, at times, epidemiological information. ‫ﻛﻞ ﻣﻨﻄﻘﺔ اﻟﮭﺎ ﻧﻮع ﻣﻦ اﻟﺒﻜﺘﺮﯾﺎت او اﻟﻔﯿﺮوﺳﺎت ﻣﺴﺘﻮطﻨﺔ وﺷﺎﺋﻌﺔ ﺑﯿﮭﺎ‬ Duration? In most patients with uncomplicated pneumonia a 5-day course is adequate When to give longer courses? patients with Legionella, staphylococcal or Klebsiella pneumonia Your Date Here Your Footer Here 36 Antibiotics ‫ﻣﺎﻛﺮوﻻﯾﺪ‬ ‫بنسلني‬ for TB Amoxicillin + 3rd gene. clavulanic acid Cephalosporin Your Date Here Your Footer Here 37  Oral antibiotics are usually adequate unless the patient has a severe illness, impaired consciousness, loss of swallowing reflex or functional or anatomical reasons for malabsorption. Clinical pearl! Your Date Here Your Footer Here 38 Supportive care Oxygen Should be administered to all patients with tachypnoea, hypoxaemia, hypotension or acidosis with the aim of maintaining the PaO2 ≥ 8 kPa (60 mmHg) or SaO2 ≥ 92%. Continuous positive airway pressure (CPAP) should be considered in those who remain hypoxic despite high-concentration oxygen therapy. Fluid balance Intravenous fluids should be considered in those with severe illness, in ‫الفيفر مثال تنشف الجسم‬ older patients and those with vomiting Inotropic support may be required in patients with shock ( ‫مثل الدوبامني ) الشغالت الي تزيد البلد فلو وكذا‬ Your Date Here Your Footer Here 39 Supportive care Treatment of pleural pain It is important to relieve pleural pain in order to allow the patient to breathe normally and cough efficiently. For the majority, simple analgesia with paracetamol, co-codamol or NSAIDs is sufficient. In some patients, opiates may be required but must be used with extreme caution in individuals with poor respiratory function. Cause respiratory failure Physiotherapy Physiotherapy is not usually indicated in patients with CAP, although it may be helpful to assist expectoration in patients who suppress cough because of pleural pain Your Date Here Your Footer Here 40 Complications Acute respiratory ‫ممكن اسحبها اذا هواي‬ distress syndrome ‫سبسس و شوك‬ Para-pneumonic effusion – common ARDS, renal failure, multi-organ Empyema Pus accumulated, ‫ﯾﺮادﻟﮭﺎ ﺗﯿﻮب ﺣﺘﮫ اﺳﻮﯾﻠﮭﺎ درﻧﺞ‬ failure Retention of sputum causing lobar Ectopic abscess formation (Staph. ‫اﻟﺴﺒﯿﻮﺗﻢ ﯾﺴﺪ اﻟﺒﺮوﻧﯿﻮﻟﺲ‬ Abcess outside lung parankyma collapse aureus) Deep vein thrombosis and Hepatitis, pericarditis, pulmonary embolism myocarditis, meningoencephalitis Pneumothorax, particularly with Arrhythmias (e.g. atrial Staphylococcus aureus fibrillation) Suppurative pneumonia/lung abscess Pyrexia due to drug hypersensitivity Your Date Here Your Footer Here 41 Prognosis Most patients respond promptly to antibiotic therapy. Fever may persist for several days, however, and the chest X-ray often takes several weeks or even months ‫ﺣﺘﮫ ﻟﻮ راﺣﺖ اﻻﻋﺮاض‬ to resolve, especially in old age. Delayed recovery suggests either that a complication has occurred or that the diagnosis is incorrect. Your Date Here Your Footer Here 42 Prevention Current smokers should be advised to stop. Influenza and pneumococcal vaccination should be considered in patients at highest risk of pneumonia (e.g. those over 65 or with chronic lung, heart, liver or kidney disease, diabetes or immunosuppression). In resource-poor settings, tackling malnourishment and indoor air pollution, and encouraging immunisation against measles, pertussis and Haemophilus influenzae type b are particularly important in children Your Date Here Your Footer Here 43 Notes on Staph pneumonia Community aqu. Pne. It Is a recognized cause of influenza-associated CAP. It also occurs as hospital-acquired pneumonia. Most common in infants, young children, and debilitated patients; A short prodrome of fever followed by rapid onset of respiratory distress; extra pulmonary symptoms ‫ﻋﺎدي ﺗﺴﺒﺐ‬ Prominent GI symptoms may also occur Early in the disease course, the chest radiograph may reveal minimal infiltrates, but within hours, infiltrates progress rapidly Pleural effusion, pneumatoceles, and pneumothorax are also common Your Date Here Your Footer Here 44 Notes on Staph pneumonia pneumatoceles ‫ھﻮاء داﺧﻞ اﻟﺮﺋﺔﺧﺼﻮﺻﺎ داﻧﻞ اﻟﻜﻮﻧﺴﻮﻟﯿﺪﯾﺸﻦ‬ pneumatoceles Your Date Here Your Footer Here 45 Notes on Mycoplasma pneumoniae Mycoplasma pneumoniae infection is a one of atypical bacterial pneumonia that is characterized by a relatively long incubation period (approximately 1– 4 weeks) and a wide spectrum of clinical symptoms and disease manifestations. The bacterium can also cause a wide array of extrapulmonary manifestations without obvious respiratory disease. ‫ﻣﺎﻛﻮ ﻣﺸﻜﻠﺔ ب رﺋﺔ‬ Your Date Here Your Footer Here 46 Notes on Mycoplasma pneumoniae Clinical Complications of mycoplasma p.: Severe complications can occur that result in hospitalization and sometimes death include: Severe pneumonia Exacerbation of asthma Encephalitis Hemolytic anemia ‫اذا ﻟﻜﯿﺖ اﻟﮭﯿﻤﻮﻏﻠﻮﺑﯿﻦ ﻧﺎزل ف ﻓﻜﺮ ﺑﺎﻟﻤﯿﻜﻮﺑﻼزﻣﻚ ﻧﯿﻤﻮﻧﯿﺎ‬ Renal dysfunction Gastrointestinal complaints Erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis. ‫اﻟﻤﮭﻢ اﻛﻮ ﻛﻮﺗﯿﻨﯿﺲ ﻟﯿﺸﻦ‬ Your Date Here Your Footer Here 47 Notes on Mycoplasma pneumoniae Antibiotic treatment: The disease is treated with macrolide, tetracycline, or fluoroquinolone classes of antibiotics. All mycoplasmas lack a cell wall and, therefore, all are inherently resistant to betalactam antibiotics (e.g., penicillin). Your Date Here Your Footer Here 48  Special types of pneumonia Your Date Here Your Footer Here 49  Hospital acquired pneumonia Your Date Here Your Footer Here Definition Most common hospital aquaied infec is UTI 2nd is pneumonia Hospital-acquired pneumonia (HAP) or nosocomial pneumonia refers to a new episode of pneumonia occurring at least 2 days after admission to hospital. It is the second most common hospital-acquired infection (HAI) and the leading cause of HAI associated death. The elderly are particularly at risk, as are patients in intensive care units, especially when mechanically ventilated; here, the term ventilator-associated pneumonia (VAP) Health-care-associated pneumonia (HCAP) refers to the development of pneumonia in a person who has spent at least 2 days in hospital within the last 90 days, or has attended a haemodialysis unit, or received intravenous antibiotics, or been resident in a nursing home or other long-term care facility. Your Date Here Your Footer Here 51 Factors predisposing to hospital-acquired pneumonia Reduced host defences against bacteria Reduced immune defences (e.g. glucocorticoid treatment, diabetes, malignancy) Reduced cough reflex (e.g. post-operative) Disordered mucociliary clearance (e.g. anaesthetic agents) Bulbar or vocal cord palsy Aspiration of nasopharyngeal or gastric secretions Immobility or reduced conscious level Vomiting, dysphagia (N.B. stroke disease), achalasia or severe reflux Nasogastric intubation ‫اذا ﺑﺎﻟﻐﻠﻂ راح ل اﻟﻠﻨﻚ‬ Lower esophegial muscle palsy Your Date Here Your Footer Here 52 Factors predisposing to hospital-acquired pneumonia Bacteria introduced into lower respiratory tract Endotracheal intubation/tracheostomy Infected ventilators/nebulisers/bronchoscopes ‫اﻟﺒﺨﺎﺧﺎت‬ Dental or sinus infection Bacteraemia Abdominal sepsis Intravenous cannula infection Infected emboli ‫ب رايت سايد اندوكاردايتسس‬ ‫اكو امبوالي تروح ل الرئة‬ Your Date Here Your Footer Here 53 Clinical features and investigation ‫ﻧﻔﺲ اﻻﻋﺮاض اﻟﺴﺎﺑﻘﺔ‬ The diagnosis should be considered in any hospitalised or ventilated patient who develops purulent sputum (or endotracheal secretions), new radiological infiltrates, an otherwise unexplained increase in oxygen requirement, a core temperature > 38.3°C, and a leucocytosis or leucopenia. Your Date Here Your Footer Here 54  The clinical features and radiographic signs are variable and non- specific Clinical pearl! Your Date Here Your Footer Here 55 Differential diagnosis Pulmonary embolism, ARDS, Acute respiratory dissetres syndrome Pulmonary oedema, Pulmonary haemorrhage and Drug toxicity. Therefore, in contrast to CAP, microbiological confirmation should be sought whenever possible Your Date Here Your Footer Here 56 Management ‫اﻛﻮ ﻣﺸﻜﻠﺔ ب اﺧﺘﯿﺎر اﻻﻧﺘﯿﺒﺎﯾﻮﺗﻚ ﻟﻜﻦ ﺑﻘﯿﺔ اﻟﺨﻄﻮات ھﻲ ﻧﻔﺲ اﻟﻜﻮﻣﯿﻮﻧﺘﻲ اﻛﻮاﯾﺮد‬ The principles of management are similar to those of CAP, focusing on adequate oxygenation, appropriate fluid balance and antibiotics. The choice of empirical antibiotic therapy is considerably more challenging, however, given the diversity of pathogens and the potential for drug resistance. Your Date Here Your Footer Here 57 Choice of antibiotics Early-onset HAP (occurring within 4–5 days of admission) The organisms implicated are similar to those involved in CAP. In patients who have received no previous antibiotics, co- amoxiclav or cefuroxime represents a sensible choice. If the patient has received a course of recent antibiotics, then piperacillin/tazobactam or a third-generation cephalosporin should be considered. Your Date Here Your Footer Here 58 Choice of antibiotics Late-onset HAP More often attributable to Gram-negative bacteria (e.g. Escherichia coli, Pseudomonas aeruginosa, Klebsiella spp. and Acinetobacter baumannii), Staph. Aureus (including meticillin-resistant Staph. aureus (MRSA)) and anaerobes. The choice of antibiotics ought to cover these possibilities Antipseudomonal cover? carbapenem (meropenem), an anti-pseudomonal cephalosporin or piperacillin–tazobactam ‫ھﻮ ﺑﻨﺸﻠﯿﻦ ﺑﺲ ﯾﺸﺘﻐﻞ ﺿﺪ اﻟﺴﯿﺪوﻣﻮﻧﺲ‬ MRSA cover? vancomycin or linezolid Your Date Here Your Footer Here 59  It is sensible to commence broad-based cover, discontinuing less appropriate antibiotics as culture results become available. Clinical pearl! Your Date Here Your Footer Here 60 Prognosis Despite appropriate management, the mortality from HAP is high (approximately 30%). Your Date Here Your Footer Here 61 Prevention Good hygiene is paramount, particularly with regard to hand- washing and any equipment used. Steps should be taken to minimise the chances of aspiration and to limit the use of stress ulcer prophylaxis with proton pump inhibitors. Oral antiseptic (chlorhexidine 2%) may be used to decontaminate the upper airway and some intensive care units employ selective decontamination of the digestive tract when the anticipated requirement for ventilation will exceed 48 hours. Your Date Here Your Footer Here 62  Suppurative pneumonia, aspiration pneumonia and pulmonary abscess Your Date Here Your Footer Here Introduction These conditions are considered together, as their aetiology and clinical features overlap. Suppuration means pus formation. According to the site of pus formation, suppurative lung diseases will comprise: 1- Lung parenchyma (= lung abscess). 2- Bronchi (= bronchiectasis). 3- Pleura (= empyema). Your Date Here Your Footer Here 64 Suppurative pneumonia Characterised by destruction of the lung parenchyma by the inflammatory process. Microabscess formation is a characteristic histological feature Your Date Here Your Footer Here 65 Lung abscess Pulmonary abscess refers to lesions in which there is a large localized collection of pus,( or a cavity) lined by chronic inflammatory tissue from which pus has escaped by rupture into a bronchus. Your Date Here Your Footer Here 66  How they develop? ‫املهم املريض يكون يتنفس ب بطء ) الن تحت تاثير الجنرل انسثيسا ( بالتالي م يكدر يطرد املايكرو اوركانزم‬ Large amount of microorganisms Occur following inhalation of septic material during operations on the nose, mouth or throat under general anesthesia, or of vomitus during anesthesia or coma, particularly if oral hygiene is poor. Also following bulbar or vocal cord palsy, stroke, achalasia or esophageal reflux, and alcoholism. Aspiration tends to localise to dependent areas of the lung, such as the apical segment of the lower lobe in a supine patient Complicate local bronchial obstruction from a neoplasm or foreign body. Your Date Here Your Footer Here 67 Microbiology ‫ ﺗﺮاﻛﺖ ﻋﻤﻮﻣﺎ‬GIT‫ﻧﻮرﻣﻞ ﻓﻠﻮرا ﻣﻞ اﻟﻤﺎوث او ال‬ Infections are usually due to a mixture of anaerobes and aerobes in common with the typical flora encountered in the mouth and upper respiratory tract. Isolates of Prevotella melaninogenica, Fusobacterium necrophorum, anaerobic or microaerophilic cocci, and Bacteroides fragilis may be identified. When suppurative pneumonia or a pulmonary abscess occurs in a previously healthy lung, the most likely infecting organisms are Staph. aureus or K. pneumoniae. Actinomyces infections (mostly A. israelii) cause chronic suppurative pulmonary infections, which may be associated with poor dental hygiene Your Date Here Your Footer Here 68 Microbiology Bacterial infection of a pulmonary infarct or a collapsed lobe may also produce a suppurative pneumonia or lung abscess. The organism(s) isolated from the sputum include Strep. pneumoniae, Staph. aureus, Streptococcus pyogenes, H. influenzae and, in some cases, anaerobic bacteria. In many cases, however, no pathogen can be isolated, particularly when antibiotics have been given. Some strains of community-acquired MRSA (CA-MRSA) produce the cytotoxin Panton–Valentine leukocidin. The organism is mainly responsible for suppurative skin infection but may be associated with rapidly progressive severe necrotising pneumonia. Your Date Here Your Footer Here 69  Clinical features Cough with large amounts of sputum, sometimes fetid and blood-stained ‫كريه الرائحة‬ Pleural pain common Sudden expectoration of copious amounts of foul sputum if abscess ruptures into a bronchus Your Date Here Your Footer Here 70 Clinical features Signs ‫هو مصخن لكن الحرارة تصعد وتنزل بحيث حته اقل كمية ممكن توصلها رح تبقيها فوك النورمل‬ High remittent pyrexia Profound systemic upset Digital clubbing may develop quickly (10–14 days) Consolidation on chest examination; signs of cavitation rarely found Pleural rub common Rapid deterioration in general health, with marked weight loss if not adequately treated Your Date Here Your Footer Here 71 Investigations Radiological features of suppurative pneumonia include homogeneous lobar or segmental opacity consistent with consolidation or collapse. Abscesses are characterised by cavitation and a fluid level. Your Date Here Your Footer Here 72 Cavitary lung lesion X-ray chest (PA view) of a patient with lung abscess A large cavity with an air-fluid level projects in the perihilar region of the right lung and is surrounded by opacified lung parenchyma. The differential for this appearance includes abscess (bacterial, mycobacterial, fungal), cavitary noninfectious granuloma, and cavitary malignant lesion. Your Date Here Your Footer Here 73 Management Aspiration pneumonia can usually be treated with ‫ﻓﻼﺟﯿﻞ‬ amoxicillin and metronidazole. Clindamycine anaerobic bacteria‫ﺣﺘﮫ اﻏﻄﻲ ال‬ Co-amoxiclav also has a suitable antibiotic spectrum but increases the risk of Clostridium difficile infection Further modification of antibiotics should be informed by clinical response and microbiological results Your Date Here Your Footer Here 74 Management CA-MRSA is usually susceptible to a variety of oral non-β- lactam antibiotics, such as trimethoprim/sulfamethoxazole, clindamycin, tetracyclines and linezolid. Parenteral therapy with vancomycin or daptomycin can also be considered. Prolonged treatment for 4–6 weeks may be required in some patients with lung abscess Physiotherapy is of great value, especially when suppuration is present in the lower lobes or when a large abscess cavity has formed. Your Date Here Your Footer Here 75 Prognosis In most patients, there is a good response to treatment and, although residual fibrosis and bronchiectasis are common sequelae, these seldom give rise to serious morbidity. Your Date Here Your Footer Here 76 Is there any role for surgery? Surgery should be contemplated if no improvement occurs, despite optimal medical therapy. Removal or treatment of any obstructing endobronchial lesion is essential. Your Date Here Your Footer Here 77  Pneumonia in the immunocompromised patient Your Date Here Your Footer Here Introduction Patients immunocompromised by drugs or disease (particularly human immunodeficiency virus (HIV) infection are at increased risk of pulmonary infection and pneumonia is the most common cause of death in this group. The majority of infections are caused by the same pathogens that cause pneumonia in immunocompetent individuals, but in patients with more profound immunosuppression less common organisms, or those normally considered to be of low virulence or non-pathogenic, may become ‘opportunistic’ pathogens. Your Date Here Your Footer Here 79 Introduction Depending on the clinical context, clinicians should consider the possibility of Gram-negative bacteria, especially P. aeruginosa, viruses, fungi, mycobacteria, and less common organisms such as Nocardia spp. Infection is often due to more than one organism. Your Date Here Your Footer Here 80 Clinical features These typically include fever, cough and breathlessness but are influenced by the degree of immunosuppression, and the presentation may be less specific in the more profoundly immunosuppressed. The onset of symptoms tends to be swift in those with a bacterial infection but more gradual in patients with opportunistic organisms such as Pneumocystis jirovecii and mycobacterial infections. In P. jirovecii pneumonia, symptoms of cough and breathlessness can be present several days or weeks before the onset of systemic symptoms or the appearance of radiographic abnormality Your Date Here Your Footer Here 81 Investigations The approach is informed by the clinical context and severity of the illness. Bronchoalveolar lavage Invasive investigations, such as bronchoscopy, BAL, transbronchial biopsy or surgical lung biopsy, are often impractical, as many patients are too ill to undergo these safely; however, ‘induced sputum’ offers a relatively safe method of obtaining microbiological samples. Your Date Here Your Footer Here 82 HRCT focal unilateral airspace opacification favours bacterial infection, mycobacteria or Nocardia bilateral opacification favours P. jirovecii pneumonia, fungi, viruses and unusual bacteria, e.g. Nocardia cavitation may be seen with N. asteroides, mycobacteria and fungi the presence of a ‘halo sign’ (a zone of intermediate attenuation between the nodule and the lung parenchyma) may suggest aspergillosis pleural effusions suggest pyogenic bacterial infections and are uncommon in P. jirovecii pneumonia. Your Date Here Your Footer Here 83 Management In theory, treatment should be based on an established aetiological diagnosis; in practice, however, the causative agent is frequently unknown. Factors that favour a bacterial aetiology include: neutropenia, rapid onset and deterioration. In these circumstances, broad-spectrum antibiotic therapy should be commenced immediately, e.g. a third-generation cephalosporin, or a quinolone, plus an antistaphylococcal antibiotic, or an antipseudomonal penicillin plus an aminoglycoside Your Date Here Your Footer Here 84 Management Thereafter, treatment may be tailored according to the results of investigations and the clinical response. Depending on the clinical context and response to treatment, antifungal or antiviral therapies may be added. Your Date Here Your Footer Here 85 THANK YOU! Do you have any questions?