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CHAPTER 3 PULMONARY MEDICINE I. Introduction to Pulmonology II. Approach to Patients with Pulmonary Conditions 1. 2. Clinical History and Physical Examination Diagnostic Procedures III. Common Pulmonary Conditions 1. 2. 3. 4. 5. 6. 7. 8. Bronchial Asthma Chronic Obstructive Pulmonary Disease Community-Acquired Pneumonia Health Care-Associated Pneumonia Pulmonary Tuberculosis Pleural Effusion Pneumothorax Superior Vena Cava Syndrome 79 SECTION 1 INTRODUCTION TO PULMONOLOGY PULMONOLOGY FORMULAS AND REFERENCE VALUES ALVEOLAR-ARTERIAL OXYGEN GRADIENT (Aa-Gradient) To compute the A-a gradient appropriate for age: Normal A – a gradient = age 4 + 4 The A-a gradient is the difference between the alveolar oxygen (PAO 2) and the arterial oxygen (PaO2)1 computed as follows: A – a gradient = PAO2 – PaO2 PaO2 is derived from patient’s ABG ; while PAO2 is computed as follows: PaCO2 PAO2 = FiO2(Patm- PH2O) – 0.8 The normal A – a gradient for a young person is -5 -10 mmHg (normally increases with age). Example: A 60 year old patient should have an A-a gradient < 19. An increased computed A-a gradient (compared to the A-a gradient appropriate for age) suggests defect in diffusion, V/Q mismatch or right-to-lung shunting. PaO2: arterial oxygen partial pressure: obtained from ABG PAO2: alveolar oxygen partial pressure If FiO2 at room air is 21%, Patm at sea level is 760 mmHg and PH2O is 47 mmHg, the formula for A-a gradient can be simplified to: PaCO2: arterial carbo dioxide pressure: also obtained from ABG 5 A – a gradient = 150 – 4 (PaCO2) - PaO2 PaO2 PFR = FiO2 PaO2 – FiO2 RATION (PFR) PaO2: arterial oxygen partial pressure: obtained from ABG FiO2: fraction of inspired oxygen DESIRED PaO2 If age < 60 years old: Desired PaO2= 104 – (0.43 x age) *Used for adjust for ventilator FiO2 settings If age 60 years and above: Desired PaO2= 80 – (age – 60) DESIRED FiO2 Current FiO2 x Computed desired PaO2 Desired FiO2 = Current PaO2 O2 FLOW SYSTEM Nasal cannula Simple face mask OXYGEN FLOW RATES 1 2 3 4 5 6 5-6 6-7 7-8 Current PaO2: obtained from ABG Computed desired PaO2: obtained previous formula using ESTIMATED FiO2 in % 24 28 32 36 40 44 40 50 60 80 SECTION 2 APPROACH TO PATIENTS WITH PULMONARY CONDITIONS CLINICAL HISTORY AND PHYSICAL EXAMINATION I. DYSPNEA A. Pathogenesis of Dyspnea DESCRIPTION Chest tightness or constriction Air hunger, need to breathe, urge to breathe Cannot get a deep breath, unsatisfying breath Heavy breathing, rapid breathing, breathing more Increased work or effort of breathing B. Variations of Dyspnea SYMPTOM Orthopnea Paroxysmal nocturnal dyspnea Acute, intermittent episodes of dyspnea Chronic persistent of dyspnea Platypnea PATHOPHYSIOLOGY Bronchoconstriction Interstitial edema (asthma, myocardial ischemia) Airway obstruction (COPD, uncontrolled asthma) Neuromuscular disease (myopathy, kyphoscoliosis) Increased drive to breathe (CHF, pulmonary embolism, moderate-severe airflow obstruction) Hyperinflation (asthma, COPD) Restricted tidal volume (pulmonary fibrosis, chest wall restriction) Deconditioning COMMENTS Common indicator of CHF, mechanical impairment of the diaphragm associated with obesity, or asthma triggered by esophageal reflux Highly suggestive of CHF More likely to reflect episodes of myocardial ischemia, bronchospasm, or pulmonary embolism Typical of COPD, interstitial lung disease, and chronic thromboembolic disease Left atrial myxoma or hepatopulmonary syndrome II. COUGH A. Duration of cough DURATION Acute cough Subacute cough Chronic cough <3 weeks 3-8 weeks duration >8 weeks COMMON CAUSES Respiratory tract infection, aspiration event, inhalation or noxious chemicals or smoke Residuum from a tracheobronchitis, such as in pertussis or “post-viral tussive syndrome” Inflammatory, infectious, neoplastic and cardiovascular etiologies B. Differential diagnoses for cough with normal chest physical examination and radiography Cough-variant asthma Gastroesophageal reflux Nasopharyngeal drainage Medications (angiotensin converting enzyme [ACE] inhibitors) III. HEMOPTYSIS 70-90% due to bronchitis, bronchiectasis, necrotizing pneumonia, tuberculosis (owing to high prevalence and its predilection to cavity formation) “BATTLE CAMP” o Bronchitis, Bronchiectasis 81 o Aspergilloma o Tumor o Tuberculosis o Lung abscess o Emboli o Coagulopathy o Autoimmune disorders, AVM, Alveolar hemorrhage o Mitral stenosis o Pneumonia The origin of blood can be identified by observing its color o Bright-red, foamy blood: usually from the respiratory tract o Dark-red, coffee-colored blood: usually from the gastrointestinal tract Principles of management: o Maintain airway patency and oxygenation o Localize the source of bleeding o Control hemorrhage: may give racemic epinephrine ET flushing (if intubated), concocted as 1 ampule of epinephrine in 9 mL normal saline solution, as 2 mL flushing q6 IV. CHEST EXAMINATION FINDINGS CONDITION PERCUSSION Normal FREMITUS BREATH SOUNDS Vesicular (lung bases) VOICE TRANSMISSION Normal ADVENTITIOUS SOUNDS Absent Resonant Normal Dull Increased Bronchial Bronchophony, Egophony Crackles Consolidation or Atelectasis (with patent airway) Consolidation or Atelectasis (with blocked airway) Asthma Emphysema Dull Decreased Decreased Decreased Absent Resonant Hyperresonant Normal Decreased Vesicular Decreased Normal Decreased Pneumothorax Pleural effusion Hyperresonant Dull Decreased Decreased Decreased Decreased Decreased Decreased Pulmonary mass Dull (over the mass) normal Normal normal Wheezing Absent or Wheezing Absent Absent or Pleural Friction Rub Decreased (over the mass) 82 DIAGNOSTIC PROCEDURES DIAGNOSTIC Chest Radiograph or Chest X-Ray (CXR) Ultrasound (US) Computed Tomography (CT) Ventilation-Perfusion (VQ) Lung Scanning Helical CT and Multidetector CT CT Pulmonary Angiography Magnetic Resonance Imaging (MRI) Pulmonary Angiography Bronchoscopy Video-Associated Thoracoscopic Surgery (VATS) DESCRIPTION Routine chest radiography (posterioanterior and lateral views) Integral part of the diagnostic evaluation involving the parenchyma, pleura, airways and mediastinum Lateral decubitus: determine whether pleural abnormalities represent freely flowing fluid Apical lordotic views: visualize disease at the lung apices Produces images using echoes or reflection of the US beam Can detect and localize pleural abnormalities Quick and effective way of guiding percutaneous needle biopsy of peripheral lung, pleural or chest wall lesions Allows distinction between densities that would be superimpose on plain radiographs Better in characterizing tissue density and providing accurate size assessment of lesions Commonly used for evaluation of pulmonary embolism (PE) PE produces 1 or more regions of VQ mismatch (e.g. regions in which there is a defect in perfusion that follows the distribution of a vessel & that is not accompanied by a corresponding defect in ventilation) Helical CT: faster scans with improved contrast enhancement and thinner collimation Multidetector CT: obtains multiple slices in a single rotation that are thinner Allows simultaneous detection of parenchymal abnormalities Test of choice for many clinicians in the evaluation of pulmonary embolism Role is less well defined than that of CT Poorer spatial resolutions and less detail of the pulmonary parenchyma Radiopaque contrast medium is injected through a catheter placed in the pulmonary artery Direct visualization of the tracheobronchial tree Performed usually with flexible fiberoptic instruments Standard technique for diagnosis and management of pleural and parenchyma lung disease 83 SECTION 3 COMMON PULMONARY CONDITIONS BRONCHIAL ASTHMA I. ETIOPATHOGENESIS Syndrome characterized by airflow obstruction that varies markedly, both spontaneously and with treatment Associated with airway hyperresponsiveness and airflow inflammation Symptoms usually demonstrate reversibility and variability o Reversibility applies to rapid improvements in FEV1 (or PEF)1 measured within minutes after inhalation of a rapid-acting bronchodilator or more sustained improvement over days or weeks after controller treatment o Variability refers to improvement or deterioration in symptoms and lung function occurring over time Mast cells, eosinophils, T-lymphocytes, and neutrophils all play a role in the pathogenesis II. CLINICAL MANIFESTATIONS History of variable respiratory symptoms AND confirmed variable expiratory airflow limitation III. History of Variable Respiratory Symptoms Typical symptoms include cough, dyspnea, shortness of breath and wheezing o May be worse at night and in the early morning hours o Triggered by exercise, laughter, allergens and cold air o Often appear or worsen with viral infections Signs include rhonchi & wheezing throughout the chest but may be normal when asthma is controlled III. Evidence of Variable Expiratory Airflow Limitation At least once during the diagnostic process when FEV1 is low, confirm that FEV1 /FVC is reduced (it is normally 0.75-0.80 in adults) Document that variation in lung function is greater than in healthy people (examples include the following): o FEV1 increases by >12% and 200 mL after inhaling a bronchodilator (bronchodilator reversibility) o Average diurnal PEF variability is >10% o FEV1 increases by >12% and 200 mL from baseline after 4 weeks of anti-inflammatory treatment PEF variability is calculated from twice daily readings (best of 3 each time), averaged over 1-2 weeks: Day’s highest PEF – Day’s lowest PEF PEF Variability = mean of the day’s highest and lowest PEF III. DIAGNOSIS A. Classification of Asthma Severity by Level of Control CONTROLLED (all of the following) Daytime Symptoms None (2x or less/week) Limitation of Activities None Nocturnal Symptoms None (Awakening) Need for Reliever None (2x or less/week) Lung Function Normal Exacerbation None B. Asthma Phenotypes PHENOTYPE Allergic Asthma PARTYLY CONTROLLED (any measure present) >2x/week Any Any >2x/week <80% predicted 1 or more per year UNCONTROLLED Three or more symptoms of partly controlled asthma in any week One in any week DESCRIPTION Most easily recognizable phenotype Most often commences in childhood Associated with a personal or family history of atopy (eczema, allergic rhinitis, food and drug allergy) Eosinophilic airway inflammation Responds well to inhaled corticosteroids (ICS) 84 Non-allergic Asthma Late-onset Asthma Asthma with Fixed Airflow Limitation Neutrophilic or paucigranulocytic airway inflammation Less responsive to ICS Common in women, presenting symptoms usually in adulthood Requires higher doses of ICS or are relatively refractory to ICS Seen in patients with long-standing asthma who develop fixed airflow limitation due to airway wall remodeling IV. MANAGEMENT Goals of asthma therapy: o Minimal (ideally no) chronic symptoms, including nocturnal symptoms o Minimal (infrequent) exacerbations o No emergency visits o Minimal (ideally no) use of as-required B2-agonist o No limitations on activities, including exercise o PEF circadian variation <20% o (near) normal PEF o Minimal (or no) adverse effects from medicine A. Pharmacologic Therapy for Asthma DRUG CLASS EXAMPLES MECHANISM OF ACTION COMMENTS/ADVERSE EFFECTS RELIEVERS Short Acting B2 Agonists (SABA) Salbutamol Procaterol Terbutaline Albuterol Short Acting Anticholinergics Ipratropium Methylxanthines Theophylline Aminophylline Stimulates adenylyl cyclase, increasing cAMP, causing bronchodilation Rapid onset of bronchodilation Best used to relief of symptoms No effect on chronic inflammation Muscarinic receptor antagonists Inhibit only the cholinergic reflex components and thereby less effective than B2-agonists Inhibit phosphodiesterase activity causing increase in cAMP levels and bronchodilation Tremors and palpitations (usually in the elderly) Minimal decrease in serum K+ Dry mouth (most common) Urinary retention and glaucoma may be observed in the elderly Nausea, vomiting and headache (most common) Arrhythmia, seizures and death at high concentration CONTROLLERS Inhaled Corticosteroids (ICS) Beclomethasone Budesonide Fluticasone Systemic Steroids Prednisone Methylprednisolone Hydrocortisone Long Acting B2 Agonists Formoterol Salmeterol Most effective antiinflammatory agents for asthma control Reduce inflammatory cell numbers and eosinophils in airway mucosa Useful for treatment of acute exacerbations Improve asthma control and reduce inflammation when Hoarseness / dysphonia and oral candidiasis Truncal obesity, easy bruisability, osteoporosis, DM, HPN, gastric ulceration, proximal myopathy, depression, cataracts Should not be given in the absence of ICS 85 (LABA) Bambuterol added to ICS, thereby allowing lower doses of ICS to be given Leukotriene Modifying Drugs Montelukast Zafirlukast Zileuton Cromones Cromolyn sodium Nedocromil sodium Inhibit mast cell and sensory nerve activation Anti-IgE Omalizumab Inhibits IgE-mediated Block leukotriene receptors (montelukast, zafirlukast) or inhibit lipoxygenase (zileuton) Less effective than ICS in controlling asthma and have less effect on airway inflammation Useful as an add-on therapy in some patients not controlled with low doses of ICS Very short duration of action needing frequent dosing Favorable safety profile Very expensive B. Initial Controlled Treatment Asthma treatment is a continuous cycle: assess, adjust treatment and review response For the best outcomes, regular controller treatment should be initiated as soon as possible after the diagnosis of asthma is made After starting initial controller treatment, review response after 2-3 months, or according to urgency o Consider stepping up if: uncontrolled symptoms, exacerbations or risks o Consider stepping down if: symptoms controlled for 3 months, low risk for exacerbations Indicated only if: Symptoms are rare Step 1 As-needed SABA with no controller No night-walking due to asthma No exacerbations in the last year Normal FEV1 Step 2 Low-dose ICS + as-needed SABA Step 3 Low-dose ICS/LABA + as-needed SABA or ICS/Formoterol maintenance + reliever therapy Step 4 Low-dose ICS/Formoterol maintenance + reliever therapy, or Medium dose ICS/LABA + as-needed SABA Step 5 Refer for expert investigation Add-on treatments: anti-IgE (Omalizumab), low dose oral steroids C. Non-Pharmacologic Therapy of Asthma Smoking cessation Regular physical activity Occupational aspects Breathing techniques V. CLASSIFICATION AND MANAGEMENT OF EXACERBATIONS MILD OR MODERATE SEVERE LIFE THREATENING Clinical Talks in phrases Talks in words manifestations Prefers sitting to lying Sits hunched forward Not agitated Agitated Drowsy, Respiratory rate Increased >30/min Confused, Accessory Not used Used Silent chest muscles Pulse rate 100-120 bpm >120 bpm O2 saturations 90-95% <90% Peak Expiratory >50% predicted or best < 50% predicted or best Flow (PEF) SABA Transfer to acute care facility Treatment Ipratropium bromide SABA Prednisolone 1mg/kg PO Ipratropium bromide 86 Controlled oxygen Controlled oxygen Oral or IV corticosteroids Consider IV magnesium Consider high dose ICS CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) I. ETIOPATHOGENESIS Characterized by expiratory airflow limitation that is not fully reversible (hallmark: airflow obstruction) Unusual in the absence of smoking or prior history of smoking, except for patients with A1-antitrypsin deficiency Elastase-Antielastase Hypothesis: remains a prevailing mechanism for its pathophysiology A. The Pathological Changes include: Chronic inflammation Increased numbers of specific inflammatory cell types in different parts of the lung Structural changes resulting from repeated injury and repair B. Encompasses the Following Conditions: Emphysema: anatomically-defined condition characterized by enlargement and destruction of alveoli “pink puffers”) Chronic bronchitis: clinical condition characterized by chronic cough and phlegm (“blue bloaters”) Small airways disease: condition where bronchioles are narrowed II. CLINICAL MANIFESTATIONS CARDINAL SYMPTOMS Most common symptoms: Cough, sputum production, exertional dyspnea SIGNS May be normal in early stages Pink puffers (predominantly emphysema): thin, non-cyanotic, prominent use of accessory muscles Blue bloaters (predominantly chronic bronchitis): heavy and cyanotic “Tripod position”: to facilitate use of accessory muscles Signs of hyperinflation: barrel chest, enlarged lung volumes on percussion (hyperresonance) Others: pursed-lip breathing, expiratory wheezing, systemic wasting, weight loss Signs of cor pulmonale (bipedal edema, ascites) in severe cases Clubbing is not a sign of COPD and should alert the clinician to other causes of clubbing III. DIAGNOSIS A clinical diagnosis of COPD should be considered in any patient who has dyspnea, chronic cough or sputum production, and a history of exposure to risk factors for the disease Risk factors: tobacco smoke (including popular local preparations), smoke from home cooking and heating fuels, occupational dusts and chemical DIAGNOSTIC TEST COMMENTS/EXPECTED FINDINGS Required to make the diagnosis Post-bronchodilator FEV1/FVC <0.70 confirms presence of persistent airflow limitation Degree of reversibility of airflow limitation after bronchodilators / steroids is no longer recommended (it has never been shown to add Spirometry to the diagnosis, differential diagnosis, or to predicting the response to long-term treatment with bronchodilators or corticosteroids) FEV1, FEV1/FVC and all other measures of expiratory airflow are reduced TLC, FRC and RV may be increased indicating air trapping DLCO may be reduced Chest radiograph Useful for excluding other differential diagnoses 87 CT scan Pulse oximetry Arterial blood gas (ABG) IV. CLASSIFICATION OF COPD PATIENT CHARACTERISTIC A B C D Low risk Less symptoms Low risk More symptoms High risk Less symptoms High risk More symptoms Low flattened diaphragms, increase in the volume of retrosternal airspace (hyperinflation) Hyperlucent lung zones with possible bullae formation and diminished vascular markings Not routinely requested May be helpful when the diagnosis is in doubt to rule out concomitant diseases Useful if surgical procedure such as lung volume reduction is contemplated To evaluate a patient’s oxygen saturation and need for supplemental oxygen therapy Should be used to assess all stable patients with FEV1<35% predicted or with clinical signs suggestive of respiratory failure or right heart failure If peripheral saturation is <92%, ABGs should be assessed Resting or exertional hypoxemia Increased alveolar-arterial oxygen tension gradient In long-standing disease, may have chronically increased arterial PaCO2 but metabolic compensation (increased HCO 3) maintains pH near normal SPIROMETRIC CLASSIFICATION GOLD 1-2 EXACERBATIONS PER YEAR <1 mMRC GOLD 1-2 <1 >2 GOLD 3-4 >2 0-1 GOLD 3-4 >2 >2 0-1 A. Classification based on Severity of Airflow Limitation in COPD using Spirometry (Post-Bronchodilator FEV1) Spirometry should be performed after the administration of an adequate dose of a short-acting inhaled bronchodilator (to minimize variability) STAGE CLINICAL FINDINGS SPIROMETRY FINDINGS FEV1/FVC FEV1 Chronic cough and GOLD 1 FEV1> 80% predicted sputum production Mild Patient unaware that lung function is abnormal Chronic cough and sputum production GOLD 2 FEV1 50 to <80% Shortness of breath on Moderate predicted exertion FEV1 / FVC Stage patients typically seek <0.70 medical attention Greater shortness of breath GOLD 3 FEV130 to <50% Reduced exercise capacity Severe predicted Fatigue Repeated exacerbations Signs or symptoms of GOLD 4 FEV1<30% predicted respiratory failure (PaO2< 60 Very Severe mmHg + PaCO2>50 mmHg) Cor pulmonale 88 B. Classification Based on Exacerbation Exacerbation of COPD: defined as an acute event characterized by worsening of the patient’s respiratory symptoms that is beyond normal day-to-day variations and leads to a change in medication Best predictor of having frequent exacerbations (2 or more per year) is a history of previously treated events C. Modified Medical Research Council (mMMRC) Questionnaire for Assessing the Severity of Breathlessness mMMRC DESCRIPTION 0 I only get breathless with strenuous exercise 1 I get short of breath when hurrying of the level or walking up a slight hill 2 I walk slower than people of the same age on the level because of breathlessness, or I stop for breath when walking on my own pace on the level 3 I stop for breath after walking 100 meters or after a few minutes on the level 4 I am too breathless or I am breathless when I’m dressing or undressing V. OVERVIEW OF MANAGEMENT A. Only Three Interventions have been demonstrated to influence the natural history of COPD Biggest impact in the natural history of COPD Nicotine replacement therapy (gum, inhaler, nasal spray, transdermal Smoking Cessation patch) reliably increases long term smoking abstinence rates Brief (3-minute) period of counseling to urge a smoker to quit results in smoking cessation rates of 5-10% Only pharmacologic therapy demonstrated to unequivocally decrease Oxygen Therapy mortality rates in COPD For chronically hypoxemic patients >15 hours / day (long term oxygen therapy) Lung Volume Reduction Surgery Segmentectomy or lobectomy of focal emphysematous areas of the lung B. Pharmacologic Therapy for Stable COPD None of the existing medications for COPD have been shown to modify the long-term decline in lung function Bronchodilator medications are central to the symptomatic management of COPD (principal bronchodilator treatment includes B2-agonists, anticholinergics and methylxanthines) MEDICATIONS COMMENTS ADVERSE EFFECTS Alters airway smooth muscle tone improving emptying of the lungs Sinus tachycardia Effects usually wear off within 4-6 hours (short acting) and >12 hours (long acting) Arrhythmias Beta2 – Agonists Regular treatment with LABA is more effective Tremors and convenient than treatment with SABA Hypokalemia Appears to provide subjective benefit in acute episodes but is not necessarily helpful in stable disease Blocks acetylcholine’s effect on muscarinic receptors Dryness of the mouth Example: ipratropium, oxitropium, and Anticholinergics tiotropium bromide Bitter metallic taste Bronchodilating effects of short-acting inhaled Arrhythmias anticholinergics lasts longer than that of shortacting B2-agonists Tachycardia Acts as nonselective phosphodiesterase Arrhythmias Methylxanthines inhibitor Seizures Examples: theophylline, doxofylline Headaches Insomnia Inhaled Addition of ICS to bronchodilator treatment Hoarseness corticosteroids appropriate for: Oral candidiasis 89 o Symptomatic patients with FEV1<50% predicted (Stages III and IV) o Repeated exacerbations Chronic treatment with systemic glucocorticoids should be avoided VI. MANAGEMENT OF STABLE COPD A. Pharmacologic Management of COPD PATIENT RECOMMENDED FIRST GROUP CHOICE A B ALTERNATIVE CHOICE SAMA pm or SABA pm LAMA or LABA or SABA and SAMA LAMA or LABA LAMA and LABA C ICS + LABA or LAMA D ICS + LABA and/or LAMA LAMA and LABA or LAMA and PDE-4 inhibitor or LABA and PDE-4 inhibitor ICS + LABA and LAMA or ICS + LABA and PDE-4 inhibitor or LAMA and LABA or LAMA and PDE-4 inhibitor OTHER POSSIBLE TREATMENT Theophylline SABA and/or SAMA Theophylline SABA and/or SAMA Theophylline Carbocisteine SABA and/or SAMA theophylline SAMA: Short acting muscarinic antagonist (e.g., Ipratropium) SABA: Short acting beta agonist (e.g. Salbutamol) LAMA: Long acting muscarinic agonist (e.g., Tiotropium) LABA: Long acting beta agonist (e.g., Salmeterol) ICS: Inhaled corticosteroid (e.g. Budesonide) PDE-4 inhibitor (e.g., Roflumilast) B. Non-Pharmacologic Management of COPD PATIENT GROUP ESSENTIAL RECOMMENDED A Smoking cessation Physical activity B-D Smoking cessation Pulmonary rehabilitation Physical activity DEPENDING ON LOCAL GUIDELINE Flu vaccination Pneumococcal vaccination Flu vaccination Pneumococcal vaccination VII. MANAGEMENT OF ACUTE EXACERBATIONS Exacerbation: event in the natural course of the disease characterized by a change in patient’s baseline dyspnea, cough, and/or sputum that is beyond normal day-to-day variations, is acute in onset, and may warrant a change in regular medication in patients with underlying COPD Change in mental status is the most important sign of a severe exacerbation in patients with very severe COPD A. Management of Severe but Not Life-Threatening Exacerbations of COPD at the ER Assess severity of symptoms, blood gases, and CXR Administer controlled oxygen therapy and repeat ABG after 30-60 minutes Increase doses and/or frequency of bronchodilator use Add oral or IV glucocorticoids Consider antibiotics (oral or occasionally IV) when there are signs of bacterial infection Consider non-invasive mechanical ventilation 90 B. Therapy for Acute Exacerbation MANAGEMENT COMMENTS Bronchodilators Inhaled B-agonists often with addition of anticholinergic agent Frequency depends on severity of exacerbation Bacteria frequently implicated in exacerbations: Streptococcus pneumoniae, Antibiotics Haemophilius influenza, Moraxella catarrhalis Most clinicians treat patients with moderate or severe exacerbations with antibiotics, even in the absence of data implicating a specific pathogen Reduces hospital stay, hastens recovery and reduces chances of subsequent Glucocorticoids exacerbations / relapses Prednisone 40 mg/day or its equivalent for 5 days Most common acute complication for steroids: hyperglycemia Oxygen Maintain O2 saturation > 90% Administration of oxygen does not reduce minute ventilation C. Indications for Ventilator Support NON-INVASIVE VENTILATION Selection Criteria Moderate to severe dyspnea with use of accessory muscles and paradoxical abdominal motion Moderate to severe acidosis (pH <7.35) and/or hypercapnia (PaCO2>45mmHg) RR >25/min Exclusion Criteria (any may be present) Respiratory arrest Cardiovascular instability Change in mental status; uncooperative patient High aspiration risk Viscous or copious secretions Recent facial or gastroesophageal surgery Craniofacial trauma Fixed nasopharyngeal abnormalities Burns Extreme obesity INVASIVE MECHANICAL VENTILATION Indications Unable to tolerate NIV or NIV failure Severe dyspnea with use of accessory muscles and paradoxical abdominal motion RR >35/min Life-threatening hypoxemia Severe acidosis (pH <7.25) and/or hypercapnia (PaCO2>60 mmHg) Respiratory arrest Somnolence, impaired mental status Cardiovascular complications Other complications (e.g., metabolic abnormalities, sepsis, pneumonia, pulmonary embolism, barotrauma, massive pleural effusion) D. Discharge Criteria Inhaled beta-agonist use no more frequent than q4h Patient is able to walk across room Patient able to eat and sleep without frequent awakening by dyspnea Patient has been clinically stable for 12-24 hours ABG have been stable for 12-24 hours Patient (or home caregiver) fully understands the use of meds Follow-up plans have been finalized and home care arrangements have been completed COMMUNITY-ACQUIRED PNEUMONIA (CAP) I. ETIOPATHOGENESIS Lower respiratory tract infection (pulmonary parenchyma) acquired in the community within 24 hours to less than 2 weeks Results from the proliferation of microbial pathogens at the alveolar level and the host’s response to those pathogens Most common access of microorganisms to the lower respiratory tract is through aspiration from the oropharynx Classic pneumonia (lobar pneumococcal) evolves through a series of changes 91 PHASE Edema Red Hepatization Gray Hepatization Resolution (Final Phase) DESCRIPTION Initial phase with the presence of a proteinaceous exudate and often of bacteria in the alveoli Erythrocytes in the cellular intraalveolar exudate Neutrophil influx is more important from the standpoint of host defense Bacteria are occasionally seen in pathologic specimens No new erythrocytes are extravasating and those already present have been lysed and degraded The neutrophilis the predominant cell, fibrin deposition is abundant and bacteria have disappeared This phase corresponds with successful containment of the infection and improvement in gas exchange Macrophage reappears as the dominant cell type in the alveolar space and the debris of neutrophils, bacteria and fibrin has been cleared, as has the inflammatory response II. CLINICAL MANIFESTATIONS Commonly presents with acute cough, abnormal vital signs of tachypnea, tachycardia, and fever with at least one abnormal chest finding of diminished breath sounds, rhonchi, crackles or wheezes III. DIAGNOSIS A. Classification and Disposition LOW-RISK CAP Stable RR <30/min Vital Signs PR <125bpm Temp 36-40oC BP > 90/60mmHg Features Chest X-Ray Disposition No altered mental state of acute onset No suspected aspiration No or stable comorbids Localized infiltrates No pleural effusion No abscess outpatient MODERATE-RISK CAP Unstable RR > 30/min PR >12bpm Temp > 40oC or <36oC BP < 90/60 mm/Hg Altered mental state of acute onset Suspected aspiration Decompensated comorbidities Multilobar infiltrates Pleural effusion Abscess ward admission B. Diagnostics for CAP DIAGNOSTICS Chest Radiography Microbiologic Studies (sputum and blood cultures) Invasive Procedures (e.g., transtracheal, transthoracic, biopsy, bronchoalveolar lavage, protected brush specimen) HIGH-RISK CAP Any of the criteria under Moderate Risk CAP, plus: Severe sepsis and septic shock Need for mechanical ventilation ICU admission COMMENTS Essential in the diagnosis of CAP, assessing severity, differentiating pneumonia from other conditions and in prognostication Best radiologic evaluation consists of standing posterioanterior and lateral views of the chest Does not predict the likely etiologic agent Optional in low-risk CAP Necessary in moderate- and high-risk CAP Options for non-resolving pneumonia, immunocompromised patients and in whom no adequate respiratory specimens can be sent despite sputum induction and routine diagnostic testing 92 IV. MANAGEMENT For patients requiring hospitalization, empiric therapy should be initiated as soon as possible after a diagnosis Empiric microbial therapy for CAP: RISK STRATIFICATION POTENTIAL PATHOGENS EMPIRIC THERAPY Previously healthy: Amoxicillin or extended macrolides (suspected atypical pathogen) Streptococcus pneumoniae Haemophilus influenza With stable comorbid illness: Chlamydphila pneumoniae β-lactam / β-lactamase inhibitor Low-Risk CAP Mycoplasma pneumoniae combination (BLIC) or secondMoraxella catarrhalis generation oral cephalosporin + Enteric Gram-negative bacilli extended macrolides (among those with co-morbids) Alternative: Third-generation oral cephalosporin + extended macrolide Streptococcus pneumoniae Haemophilus influenza IV non-antipseudomonal β-lactam Chlamydphila pneumoniae (BLIC, cephalosporin or carbapenem) Mycoplasma pneumoniae + extended macrolide Moderate-Risk Moraxella catarrhalis or CAP Enteric Gram-negative bacilli IV non-antipseudomonal β-lactam +IV Legionella pneumophila extended macrolide or IV respiratory Anaerobes (risk of aspiration) FQ No risk for P. aeruginosa: High-Risk CAP Streptococcus pneumoniae Haemophilus influenza Chlamydphila pneumoniae Mycoplasma pneumoniae Moraxella catarrhalis Enteric Gram-negative bacilli Legionella pneumophila Anaerobes (risk of aspiration) Staphylococcus aureus Pseudomonas aeruginosa IV non-antipseudomonal β-lactam +IV extended macrolide or IV respiratory FQ With risk for P. aeruginosa: IV antipneumococcal antipseudomonal β-lactam + IV extended macrolide + aminoglycoside or IV antipneumococal antipseudomonal β-lactam + IV ciprofloxacin/levofloxacin (high-dose) 1. Extended macrolides: azithromycin dehydrate, clarithromycin 2. Oral β-lactam/β-lactamase inhibitor (BLIC): amoxicillin-clavulanic acid, amoxicillin-sulbactam, sultamicillin 3. Oral second-generation cephalosporin: cefaclor, cefuroxime axetil 4. Oral third-generation cephalosporin: cefdinir, cefixime, cefpodoxime proxetil 5. IV non-antipseudomonal β-lactam (BLIC, cephalosporin or carbapenem): amoxicillin-clavulanic acid, ampicillin-sulbactam, cefotiam, cefoxitin, cefuroxime Na, cefotaxime, ceftizoxime, ceftriaxone, ertapenem 6. Respiratory fluoroquinolones: levofloxacin, moxifloxacin 7. IV antipneumococal, antipseudomonal β-lactam (BLIC, cephalosporin or carbapenem): cefoperazone-sulbactam, piperacillin-tazobactam, ticarcillin-clavulanic acid, cefipime, cefpirome, imipenem-cilastatin, meropenem 8. Aminoglycosides: gentamicin, tobramycin, netilmicin, amikacin V. PNEUMONIA RISK SCORE (CURB-65) PREDICTS MORTALITY IN CAP C Confusion of new onset U Urea (BUN) > 7 mmol/L (19 mg/dL) R Respiratory rate > 30 bpm B Blood pressure <90/60 mmHg 65 Age >65 years old Interpretation: 0-1: treat as outpatient 2: admit patient >3: consider ICU admission 93 VI. ASSESSING RESPONSE TO THERAPY A. Response to therapy is expected within 24-72 hours of initiating treatment: Temperature, RR, HR, BP, sensorium, O2 saturation, and inspired oxygen concentration should be monitored to assess response to therapy A patient is considered to have responded to treatment if: o Fever decreases within 72 hours; o Temperature normalizes within 5 days; and, o Respiratory signs, particularly tachypnea, return to normal Follow-up cultures of blood and sputum are not indicated for patients who are responding to treatment B. De-escalation of antibiotic therapy once the patient is improving, stable and has a functioning GI tract: Resolution of fever more than 24 hours Less cough and resolution of respiratory distress (normalization of RR) Improving WBC count, no bacteremia Etiologic agent is not a high-risk (virulent/resistant) pathogen (e.g. Legionella, S. aureus, or gram-negative enteric bacilli) No unstable comorbid condition or life-threatening complications such as MI, CHF, complete heart block, new atrial fibrillation, supraventricular tachycardia, etc. No sign of organ dysfunction such as hypotension, acute mental changes, BUN to creatinine ratio of >10:1, hypoxemia, and metabolic acidosis Patient is clinically hydrated, taking oral fluids and is able to take oral medications C. Duration of Treatment ETIOLOGIC ORGANISMS Most bacterial pneumonias Enteric Gram-negative pathogens, S. aureus, and P. aeruginosa Mycoplasma and Chlamydophila Legionella DURATION OF TREATMENT (days) 5-7 14 10-14 14-21 D. Failure to improve after 72 hours of treatment is an indication of reassessment Incorrect diagnosis or presence of complicating noninfectious condition (e.g., pulmonary embolism, CHF, vasculitis, MI) A resistant microorganism or an unexpected pathogen that is not covered by the antibiotic of choice Antibiotic is ineffective or causing an allergic reaction Impaired local or systemic host defenses (e.g., aspiration, endobronchial obstruction, bronchiectasis) Local or distant complications of pneumonia (e.g., parapneumonic effusion, empyema, lung absecess, ARDS, metastatic infection, endocarditis) Overwhelming infection Slow response in the elderly patient (S. pneumoniae and L. pneumophila) Exacerbation of co-morbid illness Nosocomial superinfection E. Hospital Discharge In the absence of any unstable coexisting illness or other life-threatening complication, the patient may be discharged once clinical stability occurs and oral therapy is initiated 1. During the 24 hours before discharge, the patient should have the following characteristics: Temperature of 36-37.5oC Pulse <100/min RR between 16-14/min SBP >90 mmHg Blood O2 saturation >90% Functioning GI tract 2. Repeat Chest Radiograph Not needed in patients who are clinically improving Recommended during a follow-up visit, approximately 4 to 6 weeks after hospital discharge 94 HEALTH CARE-ACQUIRED PNEUMONIA (HCAP) I. ETIOPATHOGENESIS Transition between classic CAP and typical HAP A. Ventilator-Associated Pneumonia (VAP) The greatest difference between VAP and HCAP/HAP is the return to dependence on expectorated sputum for a microbiologic diagnosis of VAP, which is further complicated by frequent colonization by pathogens in patients with HAP or HCAP Common pathogenic mechanisms include oropharyngeal colonization with pathogenic bacteria, cross-infection from other colonized patients, large volume aspiration, microaspiration around ET tub and altered lower respiratory host defenses Clinical manifestations: same in VAP as with any other forms of pneumonia: fever, leukocytosis, increase in secretions, and pulmonary consolidation on PE, along with a new or changing radiographic infiltrate NON-MDR PATHOGENS MDR PATHOGENS Streptococcus pneumoniae Pseudomonas aeruginosa Other Streptococcus spp. MRSA Haemophilius 95nfluenza Acinetobacter spp. Antibiotic-resistant Enterobacteraceae MSSA Antibiotic-sensitive Enterobacteriaceae Enterobacter spp. Escherichia coli ESBL-positive strains Klebsiella pneumoniae Klebsiella spp. Proteus spp. Legionella pneumophila Enterobacter spp. Burkholderia cepacia Serratia marcescens Aspergillus spp. B. Hospital-Acquired Pneumonia (HAP) HAP in non-intubated patients, both inside and outside the ICU, is similar to VAP save for the higher frequency of non-MDR pathogens and better underlying host immunity in non-intubated patients the lower frequency of MDR pathogens allows monotherapy in a majority of HAP cases The only pathogens that may be more common in the non-VAP population are the anaerobes (due to a higher risk of macroaspiration) More difficult to obtain lower respiratory samples appropriate for culture in non-intubated patients II. CLINICAL CONDITIONS ASSOCIATED WITH MDR PATHOGENS IN HCAP Hospitalization for > 48 hours Hospitalization for > 2 days in prior 3 months Nursing home or extended-care-facility residence Antibiotic therapy in preceding 3 months Chronic dialysis Home infusion therapy Home wound care Family member with MDR infection III. MANAGEMENT Once an etiologic diagnosis is made, broad-spectrum empirical therapy can be modified to address the known pathogen specifically Empirical antibiotic treatment of HCAP WITHOUT RISK FACTORS FOR MDR PATHOGENS WITH RISK FACTIRS FOR MDR PATHOGENS Standard recommendation is treatment with three antibiotics: two directed at P. aeruginosa and one at Majority can be treated with a single agent MRSA A beta-lactam: Ceftriaxone 2g IV q24 Moxifloxacin 400 mg IV q24 Ceftazidime 2g IV q8 or Cefepime 2g IV q8-12 Ciprofloxacin 400 mg IV q8 or Levofloxacin 750 mg IV q24 Piperacillin/tazobactam 4.5g IV q6, Imipenem Ampicillin/sulbactam 3g IV q6 500 mg IV q6 or 1g IV q8, plus Ertapenem 1g IV q24 95 A second agent against gram-negative bacteria: Gentamicin or Tobramycib 7 mg/kg IV q24 or Amikacin 20 mg/kg IV q24, or Ciprofloxacin 400 mg IV q8 or Levofloxacin 750 mg IV q24, plus An agent against gram-positive bacteria: Linezolid 600 mg IV q12, or Vancomycin 15mg/kg, up to 1 g IV q12 PULMONARY TUBERCULOSIS (PTB) I. ETIOPATHOGENESIS Caused by Mycobacterium tuberculosis Most common site for the development of TB is the lungs (85% of patients) Most commonly transmitted from person with infectious PTB to others by droplet nuclei, which are aerosolized by coughing, sneezing or speaking. Aerosolized droplets are 1-5 µm in diameter. A single cough can generate 3000 infective droplets, with as few as 10 bacilli needed to initiate infection Most infectious patients: those with cavitary pulmonary disease and laryngeal TB Typical TB lesion: epitheloid granuloma with central caseation necrosis II. CLINICAL MANIFESTATIONS In the Philippines, cough of two weeks or more should lead to high index of suspicion for PTB Cough may be accompanied by night sweats, weight loss, unexplained fever and chills, chest pain, fatigue and body malaise Absence of fever does not exclude TB Physical findings are of little utility in PTB A. General Classification of Tuberculosis CLASSIFICATION Presumptive TB DEFINITIONS Cough of at least 2 weeks in an adult (age > 15 y/o) A child (< 15 y/o) fitting criteria for TB Radiologic imaging suggestive of tuberculosis Any person who presents with symptoms or signs suggestive of TB Cough of any duration in a high risk individual or a close contact of an active TB case Definite case A patient with MTB complex identified from a clinical specimen either by culture or by a newer method such as molecular line probe assay New case Patient who never had treatment for TB or who has taken anti-TB medications for < 1 month Retreatment case (patient previously treated with anti-TB drugs for at least 1 month in the past) Patient who was previously treated for TB, and was declared cured for has Relapse completed treatment; and is now bacteriologically or clinically diagnosed TB Patient who was previously treated for TB, and treatment failed at the end of the most recent course: o Sputum smear or sputum culture positive at 5 months or later Treatment after failure during treatment o Clinically diagnosed in a patient in whom sputum studies cannot be done, without clinical improvement anytime during the course of treatment Treatment after lost to follow A patient who returns to treatment with positive bacteriology (smear or up (TALF) culture) or clinically diagnosed, following interruption of treatment for two months or more Previous treatment outcome A previously treated patient whose outcome was not known or not unknown (PTOU) documented 96 B. Classification of Tuberculosis based on Anatomical Site Affected At least 1 (or 2) sputum specimen positive for AFB, with or without radiographic abnormalities Patient with sputum culture, Culture-positive with or without radiographic abnormalities Patient with positive sputum Rapid Diagnostic testfor MTB using a rapid positive diagnostic test (e.g. Xpert MTB/Rif) with or without radiographic abnormalities Two sputum specimens negative for AFB or MTB; but with clinical or radiologic evidence consistent with active TB and there is a decision by a physician to treat as tuberculosis Smear/culture/rapid diagnostic test from an extrapulmonary site positive for AFB A patient with histologic and/or clinical or radiologic evidence consistent with active extra-pulmonary TB and there is a decision by a physician to treat as tuberculosis Smear-positive BacteriologicallyConfirmed Pulmonary TB Clinically-Diagnosed Extra-Pulmonary TB (EPTB) BacteriologicallyConfirmed Clinically-Diagnosed III. DIAGNOSIS DIAGNOSTICS Sputum Microscopy for AFB Sputum TB Culture Chest Radiograph Rapid Diagnostic Test (Xpert MTB/Rif Assay) COMMENTS / EXPECTED FINDINGS At least two sputum specimens should be sent Sputum collection: o Two sputum specimens of good quality shall be collected, either as frontloading (e.g., spot-spot one-hour apart) or spot-early morning specimens, based on the patient’s preference o The two specimens should be collected at most within 3 days Primarily recommended for patients at risk for drug resistance It is recommended in the following smear positive patients: o All cases of retreatment o All cases of treatment failure o All other cases of smear positive patients suspected to have one or more multi-drug resistant TB o All household contacts of patients with MDR-TB o In patients with HIV Recommended for patients suspected to have PTB whose sputum smears are negative Initiating TB treatment based on chest radiographs alone is discouraged Gene Xpert testing for the presence of Mycobacterium tuberculosis and Rifampicin resistance 97 Presumptive TB Cough of at least 2 years in an adult > 15 years old CXR suggestive of tuberculosis Cough of any duration in a high risk individual or close contact of an active TB case Sputum smear microscopy Positive* Negative or not done Chest Radiograph If not suggestive of TB Not TB If suggestive of TB proceed to nest step Bacteriology confirmed TB MTB (+) Rif-sensitive Xpert MTB/Rif** MTB Negative Not TB MTB Positive Next step History of previous TB treatment? No Bacteriologically confirmed TB New Case Yes MTB (+) Rif-Resistant Bacteriologically confirmed TB Retreatment Refer to PMDT$ Services for Evaluation Clinically Diagnosed TB Retreatment If no access to Xpert MTB/Rif: Decision of MD or TBDC+? Either “Not TB” or “Clinically Diagnosed TB” Yes Category I Treatment History of previous TB treatment? Category II Treatment (for Rif-sensitive) If clinically diagnosed TB No Clinically Diagnosed TB New Case *Positive: at least 1 (of 2) specimen for acid fast bacilli ** Xpert MTB/Rif: Rapid diagnostic test for the presence of Mycobacteria tuberculosis and Rifampicin resistance + TBDC: Tuberculosis diagnostic committee $ PMDT: Programmatic Management of Drug-Resistant Tuberculosis (possible MDR-TB treatment if Rifampicin Resistant TB) 98 IV. MANAGEMENT A. Treatment Regimen for TB CATEGORY I Ia II IIa Drug Resistant TB TB PATIENTS ALTERNATIVE TB TREATMENT REGIMEN Initial Phase Continuation Phase New pulmonary TB (bacteriologicallyconfirmed or clinically diagnosed) New extra-pulmonary TB (bacteriologicallyconfirmed or clinically-diagnosed), except CNS / bones or joints New extra-pulmonary TB (CNS / bones or joints) Pulmonary or extra-pulmonary, previously treated drug-susceptible TB (whether bacteriologically-confirmed or clinicallydiagnosed), except CNS / bones or joints o Relapse o Treatment after failure o Treatment after lost to follow-up (TALF) o Previous treatment outcome unknown (PTOU) o Other Extra-pulmonary (CNS / bones or joints), previously treated, drug susceptible TB (whether bacteriologically-confirmed or clinically-diagnosed) Standard regime drug-resistant (SRDR): rifampicin resistant TB or multi-drug resistant TB XDR TB regimen: extensively drugresistant TB 2 HRZE* 4 HR or 4HRE* 2 HRZE 10 HR 2 HRZES and 1 HRZE 5 HRE 2 HRZES and 1 HRZE 9 HRE Individualized based on previous treatment courses and drug sensitivity testing *if with cavitary disease, give streptomycin IM alternate days (60 days) instead of ethambutol # based on the WHO guideline, in populations with known or suspected high levels of isoniazid resistance, new TB patients may receive HRE as therapy in the continuation phase as an acceptable alternative to HR B. Drugs used for Tuberculosis DRUG DOSE (daily) Isoniazid (H/INH) 5 mg/kg, max 300 mg MECHANISM OF ACTION Rifampicin (R) 10 mg/kg, max 600 mg Pyrazinamide (Z) 25 mg/kg, max 2 g Ethambutol (E) 15 mg/kg Inhibits fatty acid synthase and mycolic acid synthesis Excellent bactericidal activity against both intracellular and extracellular actively dividing MTB Bacteriostatic against slowly dividing organisms Binds to and inhibits mycobacterial DNA-dependent RNA polymerase thereby blocking RNA synthesis Has both intracellular and extracellular bactericidal activity, both in dividing and non-dividing MTB Also has sterilizing activity Most active antimycobacterial agent available and therefore the cornerstone of first-line TB treatment Exact mechanism is unclear (fatty acid synthetase-) may be the primary target) More active against slowly replicating organisms than against actively replicating organisms Active only in acidic environment (pH<6.0) and are found within phagocytes or granulomas Inhibits arabinosyltransferases involved in cell wall synthesis, which probably inhibits the formation of arabinogalactan and lipoarabinomannan 99 Streptomycin (S) 15 mg/kg, max 1 g Bacteriostatic antimycobacterial agent which provides synergy with other drugs Least potent against MTB Inhibits protein synthesis by binding at a site in #)S mycobacterial ribosome Bactericidal against dividing MTB but has only low-level early bactericidal activity C. Managing Side-Effects SIDE EFFECTS DRUGS RESPONSIBLE WHAT TO DO? Minor Side Effects (Patient should be encouraged to continue taking medications) Gastrointestinal intolerance Rifampicin Give medication at bedtime Mild skin reactions Any kind of drug Give antihistamines Orange/red-colored urine Rifampicin Reassure the patient Pain at injection site Streptomycin Apply warm compress Give pyridoxine (Vitamin B6) Burning sensation in feet 100-200 mg daily for IsoniazId (peripheral neuropathy) treatment; 10 mg daily for prevention Give aspirin or NSAID Arthralgia due to hyperuricemia Pyrazinamide If symptoms persist, consider gout Flu-like symptoms (e.g., fever, Rifampicin Give anti-pyretics muscle pain) Major Side Effects (discontinue taking the medications) Severe skin rash Any drug (especially Discontinue anti TB drugs & (hypersensitivity) streptomycin) refer Discontinue anti TB drugs & Jaundice due to hepatitis Any drug (especially isoniazid, refer rifampicin, pyrazinamide) If symptoms subside, resume treatment & monitor clinically Impairment of visual acuity and Discontinue ethambutol & color vision due to optic refer to an ophthalmologist Ethambutol neuritis Hearing impairment, tinnitus Discontinue streptomycin & and dizziness due to damage of Streptomycin refer CN VIII Oliguria or albuminuria due to Streptomycin Discontinue anti TB drugs & renal disorder refer Rifampicin Psychosis and convulsion Isoniazid Discontinue isoniazid & refer Thrombocytopenia, anemia, Rifampicin Discontinue anti TB drugs & shock refer D. Treatment Outcomes OUTCOME Cured Treatment completed Died Treatment failure Lost to follow-up Transfer out DESCRIPTION A sputum smear positive patient who has completed treatment and is sputum smear negative in the last month of treatment and on at least one previous occasion A patient who has completed treatment, but does not meet the criteria to be classified as “cured” or “failure” A patient who dies for any reason during the course of the treatment Patient who is sputum smear positive at five months o later during treatment A sputum smear negative patient initially who turned out to be positive during treatment Patient whose treatment was interrupted for two consecutive months or more Patient who has been transferred to another facility with proper referral/transfer slip for continuation of treatment 100 Not evaluated A patient for whom no treatment outcome is assigned Patients transferred to another treatment facility with outcome unknown PLEURAL EFFUSION I. ETIOPATHOGENESIS Excess quantity of fluid in the pleural space Most common cause of pleural effusion is left ventricular failure Transudative effusion: occurs when systematic factors that influence the absorption of pleural fluid are altered Exudative effusion: occurs when local factors that influence formation and absorption of pleural fluid are altered II. CLINICAL MANIFESTATIONS Patients may present with pleuritic pain, cough and dyspnea Findings include decreased breath sounds with decreased or absent tactile fremiti and dullness on percussion Tracheal deviation and pleural rub may also be noted III. DIAGNOSIS AND MANAGEMENT First step: determine if effusion is exudative or transudative (use the Light’s criteria by obtaining LDH and protein level from serum and pleural fluid) Other diagnostics for exudative pleural effusions: o Description of the appearance of the fluid o Glucose & protein level o Differential cell count o Microbiologic studies and cytology o Work up for tuberculosis A. Light’s Criteria Exudative pleural effusions meet at least one of the following 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 These criteria misidentify -25% of transudates as exudates. If one or more of the exudative criteria arte met and the patient is clinically thought to have a condition producing a transudative effusion, the difference between the protein levels in the serum and the pleural fluid should be measured. If this gradient >31 g/L, the exudative categorization by these criteria can be ignored because almost all such patients have transudative pleural effusion B. Common causes of pleural effusion Transudative Pleural Effusions Effusion due to Heart Failure Cirrhosis Other Transudative Effusions Exudative Pleural Efusions Parapneumonic Effusion Bacterial Pneumonia Most common cause of pleural effusion Diagnostic thoracentesis should be performed: o If effusions are not bilateral and comparable in size o If patient is febrile o If patient has pleuritic chest pain, to verify that the patient has a transudative effusion; otherwise, the heart failure is treated Pleural fluid N-terminal pro-brain natriuretic peptide (NT-proBNP) >1500 pg/mL is virtually diagnostic Liver cirrhosis may give rise to pleural effusion Usually on the right side (passage of fluid from abdomen through diaphragm) Nephritic syndrome, myxedema, urinothorax Pulmonary embolism (may also be exudative) Most common cause of exudative pleural effusion (in the US) 101 Lung Abscess Bronchiectasis Empyema Effusion secondary to Malignancy Effusion secondary to Pulmonary Embolism Tuberculosis Pleuritis Hemothorax Presents with acute febrile illness consisting of chest pain, sputum production and leukocytosis If free fluid separates the lung from the chest wall by >10mm, a therapeutic thoracentesis should be performed The following factors indicate the need for a more invasive procedure (e.g., CTT insertion) o Loculated pleural fluid o Pleural fluid pH <7.20 o Pleural fluid glucose <3.3 mmol/L (<60mg/dL) o Positive gram stain or culture of the pleural fluid o Presence of gross pus in the pleural space If fluid recurs, a repeat thoracentesis should be performed If fluid cannot be completely removed, consider CTT insertion and instilling fibrinolytics or performing thoracoscopy to break own adhesions If above procedures remain ineffective, decortications should be considered Three most common causes: lung CA, breast CA and lymphoma Diagnosis usually clinched by cytologic exam of fluid if negative, thoracoscopy is the next best procedure Glucose levels may be low if tumor burden is high Patients with malignant effusions are treated symptomatically for the most part If patient’s QOL is compromised by dyspnea, pleurodesis or insertion of a small indwelling catheter may be considered Diagnosis most commonly overlooked in the differential diagnosis of a patient with undiagnosed pleural effusion Diagnosis is established by spiral CT scan or pulmonary arteriography If the pleural effusion increases in size after anticoagulation, consider recurrent emboli, hemothorax or a pleural infection Most common cause of an exudative pleural effusion in most parts of the world Usually associated with primary TB and thought to be primarily due to a hypersensitivity reaction to TB protein in pleural space Cytology shows predominantly small lymphocytes Diagnosis is established by high levels of adenosine deaminase (>40 IU/L) or interferon gamma (>140 pg/mL) in the pleural fluid Treatment of pleural TB is identical to PTB Hematocrit should be obtained on pleural fluid if initial tap reveals bloody pleural fluid If hematocrit is more than ½ of that in peripheral blood, hemothorax should be considered and tube thoracostomy should be inserted If pleural hemorrhage >200 mL/h, consider thoracoscopy or thoracotomy 102 PNEUMOTHORAX (PTX) Presence of gas in the pleural space I. ETIOPATHOGENESIS TYPE Primary Spontaneous PTX Secondary PTX Traumatic PTX Tension PTX ETIOLOGY/PATHOGENESIS Occurs in the absence of underlying lung disease Usually due to rupture of apical pleural blebs Occurs almost exclusively in smokers (those with subclinical disease) Occurs in the presence of underlying lung disease Mostly due to COPD (but have been reported in all lung disease) Penetrating or non-penetrating chest injuries Iatrogenic PTX is a subtype which is increasingly becoming more common MANAGEMENT Simple aspiration: initial treatment If lung does not expand or PTX recurs, thoracoscopic stapling of blebs and pleural abrasion Tube thoracostomy or thoracoscopy or thoracotomy with bleb stapling and plural abrasion If patient refuses surgery, pleurodesis is an option Tube thoracostomy unless very small and can be managed with supplemental oxygen or aspiration If hemopneumothorax: two chest tubes directed at each lesion Medical emergency Large-bore needle should be inserted into the pleural space through the 2nd anterior ICS and should be left in place until a thoracostomy tube can be inserted Pressure in the pleural SUPERIOR VENA CAVA (SVC) SYNDROME I. ETIOPATHOGENESIS Clinical manifestation of superior vena caval obstruction with severe reduction in venous return from the heart, neck and upper extremities Most common etiologies are lung CA, lymphoma and metastatic tumors o Lung CA (small cell and squamous cell) accounts for 85% of all cases of malignant origin o Malignant lymphoma is the leading cause of SVCs in adults The increasing use of intravascular devices has led to increasing prevalence of benign causes of SVC Other benign causes: aneursyms, thyromegaly, thrombosis, fibrosing mediastinitis, histoplasmosis or Behcet’s syndrome II. CLINICAL MANIFESTATIONS SVCs usually present with neck and facial swelling (especially around the eyes), dyspnea and cough Other symptoms are hoarseness, tongue swelling, headaches, nasal congestion, epistaxis, hemoptysis, dysphagia, pain, dizziness, syncope and lethargy which are aggravated by bending forward or lying down PE findings include dilated neck veins, increased number of collateral veins over the anterior chest wall, cyanosis and edema of the face, arms and chest More severe cases present with proptosis, glossal and laryngeal edema, obtundation and signs of cerebral edema Cardiorespiratory symptoms may occur at rest when significant airway and vascular obstruction occurs Rarely, esophageal varices may develop III. DIAGNOSIS OF SVC SYNDROME DIAGNOSTICS Chest Radiography COMMENTS / EXPECTED FINDINGS Most significant finding is widening of the superior mediastinum (more commonly on the right side) Pleural effusion occurs in 25% (often on the right side) - majority are 103 Chest CT Chest MRI Invasive Procedures (e.g., broncoscopy, percutaneous core needle biopsy, mediastinoscopy and thoracotomy) exudative and occasionally chylous May be normal in some cases Provides the most reliable view of the mediastinal anatomy Diminished or absent opacification of central venous structure with prominent collateral venous circulation No advantages over CT Necessary for etiologic diagnosis / histologic diagnosis IV. MANAGEMENT Upper airway obstruction demands emergent therapy: o Diuretics with low salt diet o Head elevation o Oxygen support o Glucocorticoids for lymphoma (no benefit in lung CA) Radiation therapy is the primary treatment for SVCs caused by NSCLC and other metastatic solid tumors Chemotherapy is effective when the underlying CA is SCLS of the lung, lymphoma or germ cell tumor Recurrent SVC may be palliated with use of intravascular self-expanding stents (however, may precipitate heart failure and pulmonary edema) The mortality with SVC does not relate to caval obstruction but rather to underlying cause 104