Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Pulmonary Board Review Lecture 1 Lisa M. Zahn, MD Mount Sinai School of Medicine Department of Emergency Medicine November 14, 2007 Lecture 1 • Pneumonia: community acquired, immunocompromised host, aspiration, pediatric • Pneumothorax • Mycobacterium tuberculosis • Miscellaneous: Pleural effusion, lung abscess, ARDS, acute chest syndrome in Sickle Cell Anemia Lecture 2 • • • • • • • Asthma COPD Pulmonary Embolism Fat Embolism Cystic Fibrosis Lung Cancer Pediatric topics: Croup, FB Pneumonia Which of the following statements regarding communityacquired pna is correct? a) Positive blood cx’s reflect the etiologic agent more accurately than do sputum cultures b) Radiographic findings are often predictive of the infectious etiology c) The incidence of positive blood cx’s is higher in pna-specific severity index Class I than in Class V d) The pna-specific severity index has been validated as a triage screening tool e) Typical pna is differentiated from atypical pna by clinical presentation a) Positive blood cx’s reflect the etiologic agent more accurately than do sputum cultures. • Pneumonia Patient Outcomes Research Team (PORT) determined 20 statistically significant criteria that, when combined, yield a pna-specific severity index (PSI). PSI is further categorized into 5 classes with associated increasing mortalities. This information is further extrapolated for use in determining the need for hospital admission and type of bed (e.g., ICU). PORT findings were validated as a mortality prediction rule, not as a method for triaging pts with CAP. • The clinical utility of blood cx’s in CAP pts with no comorbidities and lower PSI scores (Classes I-III) is low (6-11%). • The clinical yield becomes higher (about 30%) in pts with severe pna (PSI Class V). • Yield of sputum analysis is variable. Sputum cx and gram stain are best performed in high-risk hospitalized pts (e.g., intubated or ICU pts). • In contrast, positive blood cx’s reflect the etiologic agent more accurately than sputum cx’s. • The terms “typical” and “atypical” pna refer to the causative agent. • Typical refers to pna caused by pyogenic organisms (e.g, Streptococcus pneumoniae, Haemophilus influenzae) • Atypical refers to pna caused by Mycoplasma, Chlamydia, Legionella, viruses or rickettsiae. • Although CXR can provide a clue to the causative pathogen, the findings overall are nonspecific for accurately predicting a particular infectious etiology. An important consideration regarding pna in elderly pts, compared to younger patients is that: a) Elderly pts are less likely to have pneumococcal bacteremia b) Elderly pts are less likely to present in an advanced stage of illness c) Elderly pts are less likely to present with productive cough and fever d) Mycoplasma is the most common atypical causative agent in elderly pts e) Temperature higher than 38.3 c (100.9 f) is more worrisome in younger pts c) Elderly pts are less likely to present with productive cough and fever • Classic signs and symptoms of PNA, such as cough productive of purulent sputum, SOB, fever, are often absent in elderly or debilitated pts. • Initial presenting complaints can include acute confusion, weakness, tremulousness, and decline in functional status. Elderly pts are often sicker and in an advanced stage of illness in initial presentation (e.g., septic shock in absence of previous signs and symptoms). • As c/w younger adults, febrile (>38.3 c) elderly pts with PNA are more likely to have serious bacterial infection. Pneumococcal bacteremia is 3x more common in elderly pts than in younger pts with pna. • When c/w pts younger than 65, the mortality from pneumococcal pna is 3-5 times greater in the elderly (up to 40%). • The most common atypical organism in the elderly is Legionella. • Mycoplasma pneumoniae is a common cause of CAP in healthy pts younger than 40. • Poor prognostic indicators for elderly pts with pna include: hypothermia, temperature greater than 38.3 c (100.8 f), low WBC count, immunocompromise, Gram negative or staphylococcal infection, CV disease, bilateral infiltrates, and extrapulmonary disease. A 75 year old NH pt with a PMH significant only for mild dementia choked on water while sitting at a table eating his lunch. He recovered uneventfully but was sent to the ED for evaluation of aspiration pna. He is in no respiratory distress and has nl VS, including pulse oximetry, an unremarkable PE, and a normal CXR. Which of the following considerations regarding his tx is correct? a) b) c) d) e) Anaerobes have a major role in aspiration pna Antibiotics should be initiated early regardless of whether he is symptomatic Early initiation of corticosteroids will not help prevent lung injury Expectorated sputum cx’s will have high yield in identifying the causative organism He is likely to have lung involvement in the superior segments of the lower lobes c) Early initiation of corticosteroids will not help prevent lung injury. Community-acquired aspiration PNA is caused by: • • • • Streptococcus pneumoniae Staphylococcus aureus Haemophilus influenzae Enterobacteriaceae Hospital-acquired aspiration PNA, in addition to the above is caused by gram-negative organisms (e.g., Pseudomonas aeruginosa) • If patient has a hx of chronic alcoholism, severe periodontal dz, putrid sputum, evidence of necrotizing pna or lung abscess on cxr consider: Anaerobic organisms • The posterior segments of the upper lobes and the superior segments of the lower lobes are the most common sites of involvement, if aspiration occurred in a recumbent position. • The basal segments of the lower lobes, commonly RLL, are typically affected if the aspiration took place in an upright or semi-recumbent position. • Expectorated sputum cx’s in aspiration PNA has low clinical utility secondary to OP colonization. • Corticosteroids in aspiration PNA have not been supported. • Prophylactic abx are not recommended in pts with an episode of an aspiration who have nl radiographic studies and no signs or symptoms of infection. Which of the following organisms is the most common cause of pna in a pt with HIV infection and a CD4+ count of 850 cells/microliter? a) Cryptococcus neoformans b) Mycobacterium tuberculosis c) Pneumocystis jiroveci d) Pseudomonas aeruginosa e) Streptococcus pneumoniae e) Streptococcus pneumoniae • The most common cause of bacterial pneumonia in pts with HIV is Streptococcus pneumoniae. C/w nonHIV positive pts, the incidence of streptococcal pna is 9 to 10 x higher in HIV pts, and is commonly associated with bacteremia. Bacterial infections are more likely to cause pna when the pt’s CD4+ count is above 800 cells/microliter. • Haemophilus influenzae and Pseudomonas aeruginosa are also common causes of bacterial pna in HIV pts. The incidence of Haemophilus influenzae is 100 x higher in HIV pts than in non-HIV pts. • C/w other bacterial pathogens, Pseudomonas aeruginosa pna in HIV pts is more likely to cause lower WBC and CD4+ counts. • CD4+ counts between 250 and 500 cells/microliter increase the risk of infection by: Mycobacterium tuberculosis Cryptococcus neoformans Histoplasma capsulatum • CD4+ count below 200 cells/microliter increase the risk of infection by Pneumocystis jiroveci (formerly Pneumocystis carinii) • Bacterial pna, TB and opportunistic infections can result in pulmonary nodules in HIV pts. • Pleural effusions are also common in HIV pts and are often caused by Streptococcus pneumoniae and Staphylococcus aureus. • Common noninfectious etiologies of pleural effusions in HIV pts include NHL, Kaposi sarcoma and adenocarcinoma of the lung. A 48 year old man presents complaining of SOB, cough, and fever. His pulse oximetry reading is 92% on room air; CXR demonstrates a RLL infiltrate. He underwent right lung transplantation 4 weeks earlier for idiopathic pulmonary fibrosis. Which of the following statements regarding the pt’s condition is correct? a) b) c) d) e) Acute rejection can be differentiated clinically from infection Bacterial pna is a common complication during the early post-op period EBV is the most common viral infection after lung tx Prophylaxis against pneumocystis jiroveci should be initiated only in lung tx pts who have HIV infection Steroids are contraindicated for the management of acute rejection b) Bacterial pna is a common complication during the early postop period. • Lung transplantation is most commonly performed for: COPD, idiopathic pulmonary fibrosis, CF, alpha1-antitrypsin deficiency emphysema, primary pulmonary htn, sarcoidosis and bronchiectasis. • Absolute exclusion criteria for lung transplantation are: HIV infection, noncurable malignancy, active cigarette smoking, chronic HBV or HCV, and nontreatable infections. • Secondary to the use of various immunosuppressive agents, lung tx pts are at a higher risk for both opportunistic and nonopportunistic infections. • Prophylaxis against Pneumocystis jiroveci (formerly Pneumocystis carinii) with bactrim is customary after lung tx. • Acute rejection and infection are common complications during the first post-op year. Distinguishing between the two is difficult because of overlap between the signs and symptoms. • Dx requires bronchoscopy and transbronchial bx. Highdose steroids is the tx for acute rejection. • Bacterial pna is a common complication during the early post-op period, especially the first 3 months. • Among viral agents, CMV is the most common pathogen (within the first post-op year). Other viral infections (e.g., EBV, HSV) are less common, but possible as well. • Among fungi, Aspergillus species can be associated with invasive disease. For previously healthy children with community acquired pneumonia, which of the following statement is correct? a) b) c) d) e) Age is the most important factor in selecting empiric antibiotic therapy Concurrent presence of watery diarrhea reliably identifies a viral etiology Localized chest pain is most commonly associated with viral pna Viral and bacterial pneumonia can reliably be differentiated in infants Wheezing in preschool-aged children is pathognomonic for viral pna a) Age is the most important factor in selecting empiric antibiotic therapy • The organisms associated with CAP in previously healthy children differ by age. • Perinatally acquired organisms (GBS, gram negative enteric bacteria) have been identified as the etiologic agents in the first 3 weeks of life, only. Infants of this age are admitted and administered ampicillin and gentamicin with or without cefotaxime. Other organisms in this age group include CMV, Listeria monocytogenes. • In infants 3 weeks to 3 months organisms include: Chlamydia trachomatis, RSV, Parainfluenza 3, Streptococcus pneumoniae, Bordetella Pertussis (more likely to cause bronchitis), and less commonly Staphylococcus aureus. • Afebrile infants between 3 weeks and 3 months old with normal oxygen saturation, an oral macrolide such as erythromycin or azithromycin is recommended. • Afebrile infants between 3 weeks and 3 months old with hypoxia, hospital admission for IV erythromycin is recommended. • Febrile infants between 3 weeks and 3 months old, admission to the hospital for IV cefotaxime is recommended. • Infants and children between 4 months and 4 years old, the recommended outpt tx is oral amoxicillin. • Although, most commonly pna is caused by RSV, parainfluenza virus, influenza virus, adenovirus, rhinovirus. • If inpatient tx is indicated, (e.g., signs of sepsis, alveolar infiltrates, or large pleural effusions) IV amp or IV cefotaxime or cefuroxime. Bacterial organisms include Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae (although more common in the older children) and TB (in certain populations). • In children 5 to 15 years old, Mycoplasma pneumoniae is the chief cause of pna. Although Chlamydia pneumoniae is possible. Streptococcus pneumoniae is more likely for a lobar pna, and TB should be considered in certain populations. • Children 5 to 15 years old treated as outpts, oral erythromycin, azithromycin, or clarithromycin is recommended. • Children 5 to15 years old who do not have lobar or lobular infiltrates or pleural effusions but are ill enough to be admitted, IV erythromycin or IV azithromycin is recommended. • For children older than 8 years, oral or IV doxycycline may be substituted for macrolide inpt or outpt therapy. • Children 5 to 15 years old who require hospital admission, i.e., with signs of sepsis, an alveolar infiltrate, or a large pleural effusion, IV cefotaxime or cefuroxime is recommended. • Localized chest pain is most commonly associated with bacterial pna. • Other factors, such as concurrent OM, rhinorrhea, sick contacts, myalgias, diarrhea, do not reliably differentiate bacterial vs viral pnas. • Although wheezing is more commonly seen with viral pna than with bacterial pna, wheezing is not pathognomonic for viral pna. In studies that directly examined this, wheezing was seen in 435 to 56% of viral pna cases and in 16% of bacterial pna cases. Pneumothorax Which of the following conditions is most likely to be a precipitating factor for PTX? a) b) c) d) e) COPD Cigarette smoking Marfan syndrome Physical exertion Pneumocystis carinii pna b) Cigarette smoking • PTX occurs when air enters the intrapleural space (i.e., space between the visceral and parietal pleura). • Tension PTX is caused by positive pressure in the pleural space leading to decreased venous return, hypotension, hypoxia. • PTX is classified into: iatrogenic/traumatic spontaneous: primary or secondary Iatrogenic/traumatic PTX: • secondary to invasive procedures such as needle bx of the lung (50%) • subclavian line placement (25%) • NGT placement • positive pressure ventilation • other trauma Primary spontaneous PTX • accounts for the majority of pneumothoraces • no underlying lung disease • male smokers of taller than average height • relative risk is 6x higher in men than women • cigarette smoking confers a greater than 20:1 relative risk c/w non-smokers • other risk factors: changes in ambient atmospheric pressure, MVP, Marfan syndrome • physical exertion is not a factor Secondary spontaneous PTX • • • • 1/3 of spontaneous PTX underlying pulmonary disease COPD is the most common associated condition other associated lung disease: asthma, CF, necrotizing bacterial PNA, lung abscess, PCP PNA, TB, sarcoidosis, primary lung cancers, pulmonary/pleural mets. Catamenial PTX • rare cause of recurrent spontaneous PTX • occurs in association with menses • develops within 72 hours of onset of menses Clinical features of PTX: • symptoms are directly related to the size, rate of development and underlying lung disease • acute onset of pleuritic pain is found in 95% • dyspnea occurs in 80% and predicts a large PTX • decreased breath sounds on the affected side are present 85% of the time • only 5% have tachypnea over 24 breaths per minute • EKG changes, including ST changes and T-wave inversion may be seen with PTX Diagnosis: • CXR upright PA is 83% sensitive • expiratory films may slightly enhance visualization • CT scan may be more sensitive • recent studies have shown the sensitivity of US to be near 100% A 22 year-old college basketball player presents with sudden-onset SOB. Chest radiography reveals a 10% ptx. The pt has not had a prior episode of ptx. He is not in acute distress, and VS and oxygen saturation are wnl. w/o any intervention, approximately how long will it take for the ptx to resolve on its own? a) 12 hours b) 24 hours c) 36 hours d) 1 week e) 3 weeks d) 1 week Management of PTX: • If unstable (e.g., suspected tension ptx) place chest tube prior to CXR. • Observation is acceptable approach for a healthy, young pt, with a small (i.e., <20% of hemithorax) primary spontaneous PTX. Observe x 6 hours, may repeat cxr and d/c with surgical f/u if no enlargement on cxr. However, 23 to 40% of patients will eventually require tube thoracostomy. Aspiration is another option for small asymptomatic pneumothoraces. • Intrinsic reabsorption rate in intrapleural air is approximately 1 to 2% of lung volume qd. • Administration of 100% O2 increases the reabsorption rate by 3 to 4 fold. Mechanism is by lowering the alveolar partial pressure of nitrogen. As a result, the rate at which air diffuses across the pleural-alveolar barrier is accelerated. • When dischargeable, pts should be instructed to avoid air travel or underwater diving until the PTX has completely resolved. • Management of secondary spontaneous PTX is usually managed by tube thoracostomy, because less invasive approaches such as observation or aspiration has a much lower success rate. Mycobacterium tuberculosis Which of the following conditions places a patient at higher risk for the progression of TB from latent infection to active disease? a) b) c) d) e) Asthma CHF DM Influenza Smoking Risk factors for developing active TB in a previously infected pt include: • • • • • • • • • • • HIV Other immunosuppressive conditions (i.e., steroids, s/p organ tx) TB infection within the last 2 years CXR suggestive of prior TB in an untreated person IVDA DM Silicosis Head and neck CA Hematologic and reticuloendothelial disease CRF Low body weight (<10% of ideal body weight) Risk factors for acquiring TB: • • • • • • Close contact with a person known to have active TB HIV infection Homelessness Incarceration Alcoholism Occupational exposure (e.g., in hospitals, nursing homes) • Advanced age • IVDA • Immigration from areas with higher rates of TB: Asia, Africa, Latin America General Information • TB is a major global problem. More than 30% of the world’s population has latent or active TB. • TB causes 2 million deaths yearly. • TB rates remain disproportionately high in foreign-born persons, accounting for ½ of all US cases. Pathophysiology: • TB is caused by Mycobacterium tuberculosis, a slowing growing aerobic rod, multilayered cell wall which account for its acid-fast property. • Transmission occurs through inhalation of droplet nuclei in to the lungs. • Hematogenous dissemination may occur. Organism survives in areas of high oxygen content or blood flow: apical and posterior segments of the upper lobe, superior segments of lower lobe, renal cortex, meninges, epiphyses of long bones, vertebrae. • Latent TB infections are asymptomatic with positive PPD. • Latent TB will progress to active disease in 5% of cases, within the first 2 years of infection. An additional 5% will reactivate over their lifetime. • Reactivation rates are higher at extremes of age, pts with recent primary infection, immune deficiency (most notably HIV), and pts with chronic diseases (e.g., DM, renal failure) Clinical Features: • Primary TB infection is usually asymptomatic. (Usually noted with a positive PPD.) • Some pts may present with active pneumonitis or extrapulmonary disease. • Immunocompromised pts are more likely to develop rapidly progressive primary infections. • Reactivation of latent TB accounts for most active cases. • Active TB presents subacutely with: fever, cough, weight loss, fatigue, night sweats. Hemopytsis, pleuritic chest pain and dyspnea may develop. • The pulmonary physical exam is usually non-diagnostic, but rales or rhonchi may be present. • Extrapulmonary TB develops in 15% of cases. The most common form is lymphadenitis. • Also, pleural effusion or pericarditis may occur. • TB peritonitis presents insidiously after extension from local lymph nodes. • TB meningitis can occur from hematogenous spread. With symptoms of fever, HA, meningeal signs, and/or CN deficits. • Miliary TB is a multisystem disease caused by massive hematogenous spread. Most common in immunocompromised pts and children. P/w fever, cough, weight loss, adenopathy, HSM, cytopenias. • Prior partially treated TB is a rf for drug-resistant TB. • Multi-drug resistant TB is more common in HIV pts than in the general population, and has a higher fatality rate. Diagnosis: • CXR are the most useful diagnostic tool for active TB in the ED. • Active primary TB presents with parenchymal infiltrates in any lung area. • Hilar and/or mediastinal adenopathy may occur with or without infiltrates. Lesions may calcify. • Reactivation TB presents with lesions in the upper lobes or superior segments of the lower lobes. Cavitation, calcification, scarring, atelectasis and effusions may be seen. • Cavitation is associated with increased infectivity. • Miliary TB may cause diffuse small (1 to 3 mm) nodular infiltrates. • Pts coinfected with HIV and TB are particularly likely to have atypical or nl cxr • Acid fast staining of sputum can detect mycobacteria in 60% of pts with pulmonary TB (lower yield in HIV pts). Therefore a single sample may yield a false negative. Atypical mycobacteria can yield false positives. • PPD tests identifies latent, prior, or active TB infection. Results read within 48 to 72 hours. Pts with positive PPD and no active TB disease should be evaluated for prophylactic treatment with INH to prevent reactivation TB. • Immunosuppresed pts may yield false-negative results to PPD even if not fully anergic. Emergency department care and disposition: • Initial therapy includes a 4 drug regimen, until susceptibilities are available. (e.g., INH, rifampin, pyrazinamide, and streptomycin or ethambutol x 2 months). Then at least 2 drugs are continued for four more months. • Admission for clinical instability, dx uncertainty, unreliable outpt f/u or compliance, and active known MDR TB. • Admit to respiratory/droplet isolation. • ED staff should receive regular PPD skin testing. Miscellaneous Which of the following statements regarding pleural effusions is correct? a) A common cause of atraumatic hemothorax is SLE b) A pH of less than 7.3 strongly suggests pleural empyema or esophageal rupture c) Effusions associated with PE are transudative d) Management of complicated parapnuemonic effusions includes tube thoracostomy e) The most common cause in developing countries is CHF d) Management of complicated parapnuemonic effusions includes tube thoracostomy. • Parapneumonic effusion is a pleural effusion associated with bacterial pna, bronchiectasis or lung abscess. • A complicated parapneumonic effusion requires a tube thoracostomy, in addition to abx. • Most common cause of pleural effusions in developed countries is CHF. • Other causes of pleural effusions: malignancy, bacterial PNA, PE • In developing countries, TB is the leading cause of pleural effusion. Pleural effusions: exudative or transudative. • Exudative: inflammatory or neoplastic conditions, high protein content • Transudative: CHF, Nephrotic syndrome: low protein content. Form from imbalance in hydrostatic or oncotic pressures across the pleural membrane. • PE or sarcoidosis can cause either exudative or transudative effusions. • Bloody pleural effusions can be from trauma, malignancy, pulmonary infarction. • Hemothorax defined when the hematocrit of the pleural fluid is more than 50% of the peripheral blood. • Trauma can cause hemothorax. Other causes include rupture of tumor or blood vessel (ruptured aortic aneurysm). • Parapneumonic effusions, malignancies, rheumatoid effusions, TB and systemic acidosis are associated with a pleural fluid pH of less than 7.3, • A pH of less than 7 suggests empyema or esophageal rupture. Which of the following statements regarding lung abscess is correct? a) A cancerous etiology is more likely if the abscess develops in the posterior portion of the lung b) Anaerobic bacteria are more commonly found in immunocompromised pts than in immunocompetent pts c) In most cases, the abscess cavity communicates with a bronchiole d) Infectious lung abscesses commonly occur in the superior segments of the lower lobes e) Surgical intervention is commonly necessary c) In most cases, the abscess cavity communicates with a bronchiole Etiology of lung abscess includes: • • • Infectious: i.e., bacterial, fungal, parasitic Neoplastic Inflammatory • Infectious etiology, most commonly anaerobic bacteria. However in immunocompromised pts, aerobic bacteria such as Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Haemophilus influenzae have been implicated. • Pts who have conditions that predispose to aspiration, such as stroke or seizure area at higher risk for developing lung abscess. • Basal segments of the lower lobes and the posterior segments of the upper lobes are common locations for infectious lung abscesses. • Cancerous etiology should be suspected when the abscess is located in the anterior portion of the lung. • Frequently, pts with lung abscesses have a prolonged (more than 2 week) course of symptomatology. Clinical features include cough, fever, chest pain. • Hemoptysis is seen in up to 25% of cases • In 75% of cases, the abscess cavity communicates with a bronchiole. CXR will show a cavitary lesion with an air-fluid level. • 85 to 90% of pts with bacterial lung abscess can be successfully treated with broad-spectrum abx alone. Surgical intervention is rarely required. Which of the following statements regarding mediastinal disorders is correct? a) Barium studies of the GI tract are not useful for evaluating posterior mediastinal lesions b) Hamman crunch is best heard with the pt in the left lateral recumbent position c) Median sternotomy for cardiac surgery is a common cause of chronic mediastinitis d) The phrenic nerve is located within the anterior mediastinum e) TB is a common cause of acute mediastinitis b) Hamman crunch is best heard with the pt in the left lateral recumbent position Mediastinum is divided into 3 compartments: • Anterior: from the sternum to the pericardium and brachiocephalic vessels. It contains the thymus and internal mammary arteries and veins. Common lesions include thymomas, lymphomas, teratomatous neoplasms, and thyroid masses. • Middle: contains the heart, ascending and transverse aortic arches, vena cava, brachiocephalic vessels, phrenic nerves, trachea and main bronchi, pulmonary arteries and veins. Common lesions include: vascular masses, lymphadenopathies from metastases or granulomatous diseases, and pleuropericardial and bronchogenic cysts. • Posterior: lies between the pericardium anteriorly and the vertebral column posteriorly. It contains the descending thoracic aorta, esophagus, thoracic duct, azygous and hemiazygous veins. Common lesions include: neurogenic tumors, meningoceles, meningomyeloceles, gastroenteric cysts, and esophageal diverticula. • CT scanning is the dx imaging test of choice. But, for some conditions found in the posterior mediastinal compartment (e.g., hernias, esophageal diverticula) barium studies of the GI tract may be better. • Acute mediastinitis may be caused by esophageal perforation or after median sternotomy after cardiac surgery. • Chronic mediastinits is often due to TB or histoplasmosis. Sarcoidosis and silicosis are possibilities as well. • The Hamman sign, or crunch, is a physical finding associated with pneumomediastinum and or pneumopericardium. It is a crunching noise synchronous with the heartbeat, and it is best hear when the patient is in the left lateral recumbent position. Which of the following statements regarding acute respiratory distress syndrome is correct? a) b) c) d) e) Advanced age is not a risk factor CXR often reveals a unilateral focal infiltrate Early use of corticosteroids reduces mortality It is a cardiogenic pulmonary syndrome It might be associated with the use of amiodarone e) It might be associated with the use of amiodarone ARDS is a form of noncardiogenic pulmonary edema. The most common causes include: • Sepsis • Trauma • Burns • Multiple transfusions • Aspiration of gastric contents • Drug overdose (e.g., salicylates, opiates) • Other drugs that have been reported to be associated with ARDS include: TCA’s, cyclosporine, amiodarone, HCTZ, chemotherapeutic agents (e.g., bleomycin). • Among infections, bacterial PNA is a common cause. • Other conditions associated with ARDS include: toxic gas or smoke inhalation, near-drowning, radiation injury, pancreatitis, embolism, eclampsia, SAH, DIC, high-altitude exposure, oxygen toxicity, and cardiopulmonary bypass. • The ratio of arterial partial pressure of oxygen (Pao2) over inspiratory oxygen fraction (FIo2) less than 200 mm Hg is a feature of ARDS. • Age greater than 75 years, chronic alcohol abuse, metabolic acidosis, and presence of more than on predisposing condition (e.g., head trauma and sepsis) increase the risk of developing ARDS. • Pts. who develop ARDS from direct lung injury (e.g., pna, pulmonary contusion) have a lower mortality rate than those who develop ARDS from indirect lung injury (e.g., drug overdose, pancreatitis). • CXR show bilateral, diffuse, patchy or homogeneous alveolar or interstitial infiltrates involving at least ¾ of the lung fields. • Unlike cardiogenic pulmonary edema, cardiomegaly and pleural effusions are not commonly seen with ARDS. • Mechanical ventilation should be initiated with low tidal volumes (6 ml/kg predicted body weight). • To date, there is no evidence that corticosteroids reduce mortality when used in early ARDS. • Reducing left atrial filling pressures, with fluid restriction and diuretics, is an important part of ARDS management. A 26 year old man with sickle cell disease presents with atypical vaso-occlusive type arm and leg pain. He also reports dull right-side chest pain, a nonproductive cough and fever to 39 c (102.2 f). Diagnostic testing reveals an acute RLL infiltrate on CXR, WBC count of 15.2, Hgb 8.6, platelet count of 112, 000. The next most appropriate management step is: a) b) c) d) e) Admit the pt, begin broad-spectrum abx and bronchodilators, ensure oxygenation, address pain control, consider transfusion Admit the pt for IV hydration and pain control, and await the results of blood and sputum cx’s to guide appropriate abx therapy D/c the pt on a macrolide abx and oral pain medication with 24-hour follow-up Initiate bronchodilators if the pt has audible wheezing or a peak expiratory flow rate less than 50% of predicted, and base disposition decision on the response to bronchodilatory therapy Order a spiral CT scan of the chest to evaluate for the presence of PE a) Admit the pt, begin broad-spectrum abx and bronchodilators, ensure oxygenation, address pain control, consider transfusion • Acute chest syndrome is the leading cause of death and hospitalization in SCA pts. Acute chest syndrome is defined by: chest pain, fever greater than 38.5 c, tachypnea. Wheeze or cough along with a new pulmonary infiltrate involving at least one complete lung segment. Half of the pts in Vichinsky’s study were admitted with a diagnosis other than acute chest syndrome, typically vasoocclusive crisis. Consider vaso-occlusive symptoms as a prodrome of acute chest syndrome. Pts older than 20 were more likely to experience neurologic complications and death from respiratory failure. A platelet count less than 200, 000 was an independent predictor of neurologic complications. • • • • • • The leading causes of acute chest syndrome were: • Pulmonary infections 29% (e.g., Chlamydia pneumoniae and Mycoplasma pneumoniae) • Pulmonary infarctions 16% • Fat emboli 9% (diagnosed by bronchoscopic bx) • Treatment is supportive, and include admission, supplemental O2, aggressive airway management, hydration, pain control, broad spectrum abx (including a macrolide), empiric bronchodilators, and transfusions. Thank you for your attention. Questions?