^ Pulmonology Step2 CK

Pulmonology USMLE WORLD

COPD

 The most common bacteria responsible for acute exacerbation of COPD are S.pneumonia, H.inf, and M catarrhalis

 PFTsare the most useful tool to determine if a patient can benefit from the lung resection surgery  Predicted postoperative F EV1 is very helpful for this purpose

 can be derived from preoperative value and the fractional function of the lung t issue to be resected  Current ABG do not provide any useful information in this regard

 They are more useful in determining the level of respiratory compromise and appropriate ventilator settings for patients undergoing lung resection surgery

 Doubtful benefit of resection after 1- FEV12- split function quantitative lung scans & exercise testing

 A bronchodilator response test is used to demonstrate reversibility of airway obstruction It helps to differentiate between COPD and asthma, although a subset of patients with COPD may also demonstrate airway reactivity\

Acute exacerbation

Case:pt with chronic COPD , develop acute exacerbation , failed to respond to steroid and Beta agonist , ipratropium and O2what to do ?

 DoNIPPV (Noninvasive positive pressure ventilation )>> then intubate if no response. BUT WHY ?  NIPPV :associated with ↓ complications that are a hallmark of intubation, which includes infections)  NIPPV is recommended in a patient of respiratory distress with :

o RR>25 per min. o pH<7.35

o PaC02 >45 mmHg

 There is better alveolar ventilation and less fatigue of respiratory muscles by using NIPPV  Contraindication to NIPPV:

o septic,

o Hypotensive, o dysrhythmic patients

 The patient is already on oxygen therapy, but she is hypercapnic as well as acidotic

Note: In COPD patients, PCO2 is elevated at baseline and it does not stimulate the respiratory center, unlike in normal individuals. Their only drive to increase the respiratory rate is

hypoxia

 If you just provide oxygen, it, in fact, worsens the situation

 You should provide NIPPV to provide more oxygen and to wash out the CO2 Caution

 It is always better to avoid intubation, if possible, because of various complications associated with intubation ↑ incidence of nosocomial infections, ↑ long-term mortality in these patients

 However, if the patient does not respond to NIPPV, then intubation should be considered

 Systemic steroids are the first line therapy of the acute exacerbation of COPD but are relatively ineffective for chronic maintenance therapy  The only two modalities that can decrease mortality in patients with

COPD are:

o home oxygen therapy o smoking cessation

This patient has complete left lung collapse (complete opacity), possibly from mucus plugging and obstruction He also has symptoms of respiratory failure like confusion and sweating

He needs urgent bronchoscopy and removal of the mucus plugs

The removal of secretions or plugs is associated with rapid improvement in Pa02

“Please try to understand the various Tx used for COPD It is a very high yield topic in board exams Tx of COPD

1st _{line Anticholinergic drugs (Ipratropium bromide)} 2nd _{lineBeta-2 agonists like albuterol}

Inhaled steroids like beclomethasone MDl are not useful

3rd _{– 4}th _{Aminophylline or oral Theophylline ↑ the diaphragmatic contraction and help breathing} Systemic steroids are the first line therapy of the acute exacerbation of COPD but are relatively ineffective for chronic maintenance therapy

Antibiotics therapy should be used empirically for acute exacerbation of COPD and should cover Streptococcus pneurnonae, Haemophilus influenza, and Moraxella catarrhalis

 The only two modalities that can decrease mortality in patients with COPD are: o home oxygen therapy

o smoking cessation

LTOT( Long-term supplemental oxygen therapy)

 Once the patient qualifies for long-term oxygen therapy, it is continued for life  The criteria for initiating long-term oxygen therapy in COPD patients are as follows

1- All COPD patients with PaO2 < 55 mmHg or SaO2 < 88% on room air

2- Patient with cor pulmonale, evidence of pulmonary HTN or hematocrit> 55% should be started on home oxygen therapy even when PaO2 is 56-59 mmHg with SaO2 > 89%

3- Home oxygen may also be used in patients who has resting awake PaO2 > 60 mmHg with

Sa02 > 90% if they become hypoxic during exercise or sleep (noctumal hypoxia)

The dose of oxygen should be titrated such that SaO2 is maintained at > 90% during sleep, normal waking, and at rest.

Survival benefits of home oxygen are significant when it is used for a minimum of 15 hours a day Note:In any case of COPD the biggest contributor to mortality is Hypoxia pulmonary

vasoconstriction↑ pulmonary artery pressure Pulmonary Arterial Hypertension progressive right heart enlargement right heart failure death.

 After quitting smoking, home oxygen therapy is the only modality known to prolong survival in COPD

Emphesema

alpha- 1 anti-trypsin deficiency :

Any emphysema in a non-smoker,

emphysema presenting in the 3-rd decade any emphesematous changes in the lower lobes

Another diagnostic clue in this patient is the episode of neonatal jaundice, which occurs in 26 % of the patients

Open lung biopsy or video assisted lung biopsy is not needed in this patient, as diagnosis can be made by Dx serum alpha-I anti-trypsin levels

High resolution CT scan should be considered only after the assessment of alpha-I anti-trypsin levels

ASTHMA

 Indicators of sever attack:

o N-↑ PCO2 values indicates CO2 retention because of severe airway obstruction (air trapping) and or respiratory muscle fatigue

o Speech difficulty, o Diaphoresis, o Altered sensorium, o Cyanosis,

o Silent lungs Exercise induced asthma

 Beta agonists and mast cell stabilizers both play an important role in the management of exercise-induced asthma

 It should be noted that aerobic exercise and cold air are more likely to predispose to exercise induced asthma

 Exercise induced asthma should not be confused with post exercise fatigue and seasonal asthma

 Patient with exercise induced asthma experiences chest discomfort, wheezing, cough, breathlessness, fatigue, and abdominal discomfort in some cases

 The symptoms may be underreported in some cases due to fear of loosing position in the team

 Treadmill exercise challenges with pre exercise and post exercise PFTs ma y help in the diagnosis Acute bronchopulmonary aspergillosis

 Characterized by

o worsening asthma;

o fleeting pulmonary infiltrates; o ↑ IgE;

o peripheral eosinophilia;

o immediate skin hypersensitivity reaction to aspergillus antigen; o precipitating antibodies against aspergillus in serum

o coughing brownish mucous plugs

 Oral prednisolone is the Tx of choice for ABPA which is a hypersensitivity reaction to inhaled aspergillus antigens

 Oral itraconazole ↓ steroid requirement in patients with ABPA and improves pulmonary function BUT the mainstay of Tx is oral prednisolone

 CXR typically shows a solid mass surrounded by a radiolucent crescent (crescent sign, Monod's sign)  Any case of bronchial asthma + eosinophils >10 %==>should ↑ the suspicion for parasitic infestations

Central bronchiectasis

The common diagnostic features of ABPA include 1. Asthma like symptoms

2. ↑ IgE

3. HypereosinophiIia 4. Central bronchiectasis 5. Positive Aspergillus Skin test

Whenever a patient with asthma is suspected of having ABPA,skin testing with A antigen is the first diagnostic step

 negative, Dx of ABPA is ruled out

 positive, serum precipitins against Aspergillus fumigatus and IgE level are checked

ABPA is excluded if IgE levels are <1OOOng/ml or if serum precipitins against Aspergillus fumigatus are absent

immediate wheal and flare reaction to Aspergillus fumigatus (type 1 hypersensitivity) Aspirgilloma

 Aspergilloma can grow in the apex of the lung but does no t cause arm pain

 hemoptysis, fever, weight loss and a chronic cough

 The mass is usually mobile and moves with position  Dx finding of hyphae in the specimen

 The occasional aspergilloma can spontaneously regress

 CXRcrescent radiolucency next to a rounded mass

 Cavitary lesions may form because of destruction of the underlying pulmonary parenchyma, and debris and hyphae may coalesce and form a fungus ball, which lies free in the cavity and moves around with position change

 Prophylactic resection is controversial, although some recommend resection if isolated disease is present in good risk patien

Churg-Strauss syndrome



allergic granulomatosis

 multisystem vasculitic disorder

 unknown etiology

 affects skin, kidney, nervous system, lungs, GI system and heart.

 There is usually a history of asthma followed by the development of fever and marked eosinophilia at which time asthma may have become better.

 The disease is severe and requires treatment with glucocorticoids and sometimes with immunosuppressants

 A CSS-like syndrome has been noted in patients who have been successfully treated for chronic steroid dependent asthma with the leukotriene receptor antagonists (zafirleukast)

 Up to 75% of the patients with CSS have evidence of peripheral neuropathy

 This patient has evidence of peripheral neuropathy (mononeuritis multiplex)

 The disease is severe and requires Tx with glucocorticoids and sometimes with immunosuppressants

Job Syndrome

 recurrent bacterial infections  markedly elevated IgE levels

 Bacterial infections usually caused by staphlococci and the skin is the most frequent site of involvement.

 Opportunistic infections (LIKE CANDIDA , pcp)  Neutrophils exhibit impaired chemotaxis

 Some patients have coarse features while others are fair

 Other allergic disorders like eczema, asthma, allergic rhinitis may be present

 Txis intermittent or continuous antibiotics

Wiskott-Aldrich syndrome

 triad of eczema,

thrombocytopenic purpura recurrent pyogenic infections

 IgE and IgA levels are high

 IgM levels are low

 Lymphoreticular malignancies are common in such patients

Chronic Eosinophilic Pneumonia (CEP)

 the most common eosinophilic pneumonia in the US

 systemic symptoms  fever, malaise, anorexia and weight loss for several weeks or months

 Pulmonary symptoms cough and breathlessness

 Sometimes patients have Hx of bronchial asthma or allergic rhinitis

 Chest auscultation shows crackles or wheezing

 CXR reveals peripheral infiItrates that are photographic negative of pulmonary edema and this radiographic finding is pathognomonic of this chronic eosinophilic pneumonia

 BAL eosinophils >40% suggestive of chronic eosinophilic pneumonia

 Glucocorticoid therapy results in rapid resolution of symptoms and radiographic clearing

 CEP who presents with systemic symptoms of fever, malaise, anorexia and weight loss for several weeks or months you should suspect Cherg Strauce S

 Some times the presenting symptom of CCS is CEP

 However, CEP usually does no t have granulomas on biopsy and generally does not involve organs other than the lung

 Glucocorticoid therapy results in rapid resolution of symptoms and radiographic clearing

Lung CA

 A lung mass with cartilage is most likely a hamartoma and can be observed

 Most common benign tumor of the lunghamartoma.

SVC syndrome

 Today, the most common cause of superior vena cava obstruction is bronchogenic CA. o Lung abscess and pneumonia  Never.

 In the past various surgical procedures were devised to relieve the symptoms of SVC obstruction, but today, angioplasty with stenting is the standard of care.

Pancoast

 Preoperative radiation is administered before resection of this tumor.

 Pancoast tumors may be of any histology but the majority are either SCC or adenocarcinomas

 When the tumor invades the lower brachial plexus, it can cause severe pain in the arm along the ulnar nerve

 In a smoker with arm pain, cough and weight loss, a mass in the lung apex is a Pancoast tumor untiI otherwise proven

Note:Carcinoid tumors are slow growing and have the best prognosis of all lung cancers

 NoteAny chronic smoker with

HPO(Hypertrophic osteoarthropathy)

should have a CXR to rule out malignancy

 HPO is associated with chronic proliferative periostitis of the long bones, clubbing, and synovitis

 HPOSCC & AdenoCA

 Due to high incidence of lung cancer among smokers, it should be suspected in any smoker presenting with recurrent pneumonia order HRCT

Incidental Lung nodule

 ASx + lung mass, the first step is to get previous chest x rays for comparison The things that you need to remember are

1- Lesions >3 cm are more likely to be malignant

2- Lesions with irregular borders are likely to be malignant where as smooth borders indicate benign nature

3- Presence of “eccentric" calcification indicates malignancy

Pneumonia

 Any patient with fever, night sweats and copious foul smelling sputum has anyone of these three conditions:

1- Bronchiectasis 2- Lung abscess

3- Anaerobic pneumonia

 Sputum gram stain a specimen that contains >25 PMN & <10 epithelial cells per low power field represents a purulent specimen; however, it is very nonspecific, and you often see the oropharyngeal flora.

 Many physicians do not order this test for CAP, since it is often difficult to identify the microbiologic cause of the pneumonia ….Most often the treatment is empirical after the chest x-ray

 Obtaining routine sputum culturesis also controversial =1- difficult to interpret 2- fastidious organisms overgrow the organisms that actually cause pneumonia 3- difficult to interpret if there is a colonizer, such as MRSA and pseudomonas



Mycoplasma serology  rarely performed, (not cost effective) and most of the empirical antibiotics (azithrornycin, levofloxacin, gatifloxacin) often cover these atypical organisms

Clue In patients with fever and cough after upper GI endoscopy suspect anaerobic lung infection Clindarnycin and ampicillin plus metronidazole are the commonly used agents for this infection

 Doxycycline is a good antibiotic for outpatient community acquired pneumonia

were

the macrolide resistance is suspected

 Levofloxacin covers atypical organisms also and is often used in the inpatient setting of CAP //HAP

 TMP+SMX is the drug of choice pneumocystis carinii pneumonia

o The combination has good synergism and can be used for abdominal infection in combination with metronidazole

 The new generation quinolones (levofloxacin or gatifloxacin) is being extensively used for the inpatient Txof CAP

 For the management of out.patient Tx in stable and low-risk patients (no other cardiopulmonary risk factors, not hypoxic), either azithrornycin or doxycycline can be used

 Ampicillin not used for CAP since quite a number of strep pnuemo are resistant, and it does not cover atypical organisms

 Bactrim the drug of choice for uncomplicated cystitis and sinusitis It is not the first line drug for CAP

 Noteonly new generation fluoroquinolones have excellent streptococcal coverage

 Ciprofloxacin does NOT have good streptococcal coverage and also does NOTcover atypical organisms

 Vancomycin is used for suspected MRSA infection

 When pneumonia fails to heal after two weeks of appropriate antibiotics, a CT scan of the chest followed by bronchoscopy is indicated to ensure that the bronchus is not blocked and there is no lung abscess

Caution:

 Chest tube placed in an acute pneumonia can lead to a bronchopleural fistula.

o This can lead to a significant problem, as these fistulas do not readily close in the presence of an infection

o Because of the contamination of the pleural space, one risks causing an empyema

o There is no role for a chest tube unless a parapneumonic effusion or empyema is suspected

Empyema

 

The individual will usually present with a low-grade fever, and

empyema is best diagnosed

with a CT scan

 When the empyema is localized, complex, and has a thick rim, only surgery is the answer  In surgery, the thick pleural peel is removed, the pus is removed, and the chest is drained  All old blood clots are drained and removed

 Note:

o Empyema, which is recent in onset, can be removed by fibrinolytic Tx o Both STK and urokinase have been used

o However, in a patient with a recent motor vehicle trauma, fibrinolytic therapy is contraindicated

o In addition, the fibrinolytics usually do not have much success when the empyema is loculated and has a thick rim round it

o

ASx pulmonary nodule Triad     LUNG     SKIN  BONE

Primary pulmonary infection has nonspecific features like fever, fatigue, dry

cough, weight loss, and pleuritic chest pain dimorphic fungus

Mississippi and Ohio River valleys and Central America

Wisconsin, Mississippi river belt or Ohio River Belt

Arizona, New Mexico, Texas, Central and South USA

soil with a high

concentration of bird or bat

guano droppings

Cutaneous findings like erythema multiforme and erythema nodosum as well as arthralgias are

immunologically mediated and may be present in some cases Sx self-limiting fever,

chills, and a non-productive cough

CXRpaten, lobar or multinodular lobar Infiltrates.

Chronic cavitary ,

fatalolder COPD patients

CXR50%--> no abnormality

most common abnormality unilateral infiltrate with hilar adenopathy on the same side

A lung cavity may be present in some cases Sometimes there is evidence for a

Histoplasmosis is

the most common fungal infection in theUSA

Note:G-negative bacilli accounts for <

2%

of CAP, but account for most of the nosocomial infection and have high mortality rates

 GNB pneumonias are rare in healthy individuals and usually occur in infants, the

elderly.

alcoholics, and an immunocompromised host, especially with neutropenia

 The usual pathophysiological mechanism is colonization of the oropharynx, followed by micro aspiration of upper airway secretions

TB reactivation in HIV+

 chronic cough, weight loss, fever and malaise + bilateral apical consolidation  typical for reactivation tuberculosis

 Mycobacterial infection occurs earty in the course of disease with CD4 counts >200/microL Histoplasma capsulatum on HIV +

 Disseminated fungal infection takes place when HIV infection is advanced and radiography usually shows a miliary pattern

HHV-8 Kaposi us sarcoma, which usually has cutaneous findings and pulmonary involvement, which may be asymptomatic or mild

CXRusually shows a pulmonary nodule or pleural effusions

PCP

 immunocompromised CD4<200

 atypical pneumonia,

 Its natural habitat is the lung, and the incubation period ranges from 4-8 weeks (note:after 2nd _{dose of} chemo)

 It is airborne transmitted

 Characterized by: dyspnea, fever, and a nonproductive cough

 PE t achypnea. tachycardia. and cyanosis with minimal chest findings

 CXRBi lateral diffuse interstitial infiItrates beginning in the perihilar region is a characteristic finding

 may disseminate outside the lung, and the most common sites of extrapulmonary involvement are the lymph nodes, spleen, liver, and bone marrow

Klebsiella pneumonia, “Friedler’s pneumonia  most frequently affect the upper lobe

 current jelly-like sputum with tissue necrosis and

early

abscess formation

 fulminant course

 Alcoholics

 capsulated G - Bacillus  grows as mucoid colonies

Aspiration Pneumonia

 Impaired swallowing and epiglottic reflex are frequent abnormalities in pts with advanced dementia  Anaerobic bacteria in combination with some aerobic oral flora (eg ,viridans streptococci) are the

 Note:Pulmonary congestion due to LVF impairs lymphaticand venous drainage and can predispose to pneumonia

 Advanced GERD can cause aspiration of gastric content, bronchoconstriction, and pneumonia

Legionella

 gram-negative bacteria known to cause CAP & HAP

 contamination of water sources like air conditioners  Pulmonic +

GI

Sx

 fatigue, malaise, confusion, and fever with chills, productive cough, chest pain, non - bloody diarrhea and abdominal pain

 PEmay show tachypnea. tachycardia. hypotension, ↓ breath sounds with dullness on percussion Labs proteinuria, hyponatremia and hematuria

 usually cannot be seen under ordinary gram staining

 Sputum analysis will reveal neutrophils

 Erythromycin is the treatment of choice

 Remember pneumonia, Hyponatremia and diarrhea are almost classic for Legionella

 Legionella pneumonia should be suspected in those who have not responded t o Beta.actem antibiotics

 5% of CAP and up to 30% of nosocomial pneumonia

 More characteristic features suggestive of Legionella pneumonia are the presence of hyponatremia (sodium of less than 130 mmol/mL)

 Gram stain smear of respiratory secretions showing many PMNs but very few visible organisms

 CXR paten, interstitial inflammation and unilateral lower lobe involvement, which may progress to areas of consolidation over a few days

 definitive Dx urinary Legionella antigen testing using an ELISA test.

 The treatment of choice is high dose erythrornycin or azithrornycin

 The most commonly used method of decontamination is periodic superheating and flushing of w

ater supplies

 This method is particularly useful for urgent disinfection during an outbreak

 Hyperchlorination is no longer recommended because Legionella species are relatively chloride-resistant

 Biocides are also relatively ineffective

 it is not an encapsulated organism and does not produce mucoid colonies



Mycoplasma pneumonia also does not usually respond to penicillins or cephalosporins: however, it rarely gives severe illness

 DDx :Streptococcus, Haemophilus and Moraxella usually respond to beta.lactem antibiotics

 a common respiratory pathogen in teenagers  mostly It causes pharyngitis or bronchitis only

 Pneumonia develops in a few cases

 The cough is usually dry Usually ,but it may be productive of white blood-tinged sputum

 Many patients with pneumonia have upper respiratory tract signs and symptoms including a sore throat and rhinorrhea

 CXRoften appears worse than symptoms suggest

 Extrapulmonary manifestations involving the skin, heart,nervous or hematopoeitic system and they provide the only clinical clue to the Dx

 SJS is one of the extrapulmonary manifestations

 Mycoplasma does not have a cell wall and thus does not stain with gram-stain

 Dx is inadequate since most laboratories do not process cultures of the organism, serology requires paired serum specimens, and PCR-based testing is not widely available. Thus, most treatment is empirically .

Bronchiectesis

 The most serious complication of bronchiectasis is hemoptysis

 Note Respiratory failure can occur in bronchiectasis, but is a rare entity The majority of patients have a chronic insidious course

 a common finding in CF patients and may be the only finding in adults



Bronchiectasis secondary

to CF is often limited to the upper lobe and sputum generally

grows pseudomonas

Cystic Fibrosis

 Sweat chloride test (>60 mEqil) is the gold standard

 preferred over direct mutation analysis as more than 1,250 mutations in CFTR can lead to cystic fibrosis

 So gene testing confirmatory.

Lung Abscess

 Most cases of primary lung abscess are due to aspiration, periodontal disease or gingivitis

 Common causes of altered consciousness are alcoholism, general anesthesia, drug overdose, stroke, seizures, diabetic coma, shock or other serious illnesses

 Secondary lung abscess (obstructive) is most commonly seen in patients with lung malignancy  The location of lung abscess depends on the etiology In case of aspiration, the primary site of

abscess is the posterior segmen t of right upper lobe or apical segmen t of righ t lower lobe especially in recumbent position

 This is because these segments are in direct continuation of right bronchus Same segments on left side are less likely to develop post aspiration lung abscess because right bronchus has relatively more straight course than the left one

Note:  Basal segment of the right lower lobe abscess might be seen in case of transdiaphragmatic infection from amebic/pyogenic liver abscess

Pneumothorax

CXRno bronchovascular markings on the half of the right lung

 Pleural blebs small, <2 cm, subpleural collections of air contained within the visceral pleura, resulting from ruptured alveoli.

 The blebs are usually found at the apex of the upper lobe or the posterior apex of the lower lobe

 These blebs are often accompanied by apical fibrosis

 Blebs are well-demarcated from the normal parenchyma and communicate with it, via a narrow neck

 The most likely cause of a spontaneous pneumothorax is rupture of small subpleural blebs.

 A familial tendency has been described

 Blebs are best Dx with a CT scan of the chest  If the PTX is recurrent, then bleb excision is curative E

mphysema

 Most patients with emphysema and PTX will present with chest pain, respiratory distress, hypoxia & hypercarbia.

 Because of their limited pulmonary reserve, these patients may not even tolerate a small pneumothorax

 Dx CSR and tube drainage is almost always required to reexpand the lung



PTX & CA

 PTX may develop as a result of rupture of an ischemic primary tumor or metastases into the pleural space

 PTX is most frequently associated with metastatic sarcoma

 Tube drainage is always required to re-expand the lung

Lymphangioleiomyomatosis (LAM)

 a diffuse cystic disorder seen in young woman of childbearing-age

 It is due to proliferation of atypical smooth muscle through out the lung

 present with cough, dyspnea, hemoptysis and PTX

 The lung surface is covered with tiny cysts

 Although the natural history of the disorder is not known, the majority of patients die with 10 years

 Up to 50% of patients develop spontaneous PTX and often this is bilateral, recurrent and may require pleurodesis

Subcutaneous emphysema

 when an individual with asthma presents with subcutaneous emphysema, the

first thing one wants to

rule out is a

pneumothorax=> CXR

 commonly seen in severe asthmatics

 presents as crepitus over the neck and chest.

 It may appear very frightening, but does not produce any respiratory distress

 However, a CXR is a must to ensure that there is no pneumothorax

 One may also have a tracheobronchial rupture and this may present with subcutaneous

emphysema However, this is more common in trauma and bronchoscopy may be required

 Once the CXR is done, and if no pneumothorax is seen, the patient can be observed.

 Subcutaneous emphysema does not require any formal treatment , save for

observation

Note:

 Endotracheal intubation is not required for SC emphysema

 Even though they may appear with significant facial swelling, the majority of these patients are in no respiratory distress

 Criteria for mechanical ventilation is based on physical appearance of the patient, blood gas, acidosis and oxygen saturation

 Hyperparic O2 no role.

 CT if suspected bronchial,esophageal tear.

"Extremely high yield question for USMLE”

the first step is Diagnostic thoracentesis (except in patients with classic signs and symptoms of CHF) Bronchoscopy is a close alternative when suspect CA ; however, this requires sedation and is

considered to be a relatively invasive procedure

This will be the next step if the pleural fluid cytology is non-diagnostic and the patient has lung mass If cytology is positive for lung cancer, then the patient does not require a bronchoscopy

 Actually.CHF is the most common cause of pleural effusion (right side)



The determination of pH is important in parapneumonic effusions in which

a value of

<

7.2 requires a chest tube aspiration to prevent empyema

 Normal pleural fluid pH is approximately 7.64 .

 Pleural fluid pH < 7.3 indicates pleural inflammation .

 pH of 7.35 is consistent with transudative pleural effusion .

SepticEmboli

 Drug abuser Tricuspid valve endocarditis S.aureus PC: acute endocarditis +pulmonary infarction and abscess Sx fever, pleuritic chest pain, hemoptysis and malaise

 CXR  peripheral well-circumscribed lesions with cavitation

 Surgery is required in the majority of these patients( Valve repair or replacement is therapeutic)

 Note:Atelectasis may be seen in patients with endocarditis but is a result of the infection and not the cause of endocarditis.

 Note: Pleural effusions in a drug abuser may occur from a parapneumonic effusion

 ClueIn a drug abuser, presence of well-circumscribed lung opacity is most likely due to embolism of infected vegetation causing a pulmonary infarct

' This concept is extremely important for the USMLE exams

Proximal (above knee veins) DVT of lower extremities is the most frequent source of PE. Proximal veins of lower extremity are iliac, femoral and popliteal

Pulmonary Embolisim

 Pulmonary infarction after a pulmonary thromboembolism is very rare.

 Death of lung tissue is very rarely seen after embolism because of the copious oxygen supply

 The lung receives oxygen from the pulmonary arteries, the bronchial arteries and from the airways

 Thus infarction occurs rarely and its appearance usually is associated with compromise of bronchial arterial blood flow and/or airways to the involved area

 Such compromise is promoted by existence of other cardiac or pulmonary pathology, such as left ventricular failure, mitral stenosis or COPD

 When the x-ray is normal and suspicion is still high, the next step is obtain a V/Q scan If the via scan is of low probability with a normal x-ray, one can exclude the diagnosis of PE

 Hampton hump-cone shaped area of opacification

 Westermark sign-dilated pulmonary artery with distal oligemia

 Factor V Leiden is the most common inherited disorder causing hypercoagulability and predisposition to thromboses, especially DVT of lower extremities

 Therapeutic INR for most clinical indications of warfarin is 2 to 3  These conditions include VTE , VHD, and AFib .

 A higher INR of 3.0 to 4.5 is required only in ceratin clinical settings like prosthetic heart valves  Patients with suspected PE should have a CXR and ABG, followed by EKG and V/Q scan. Note: V/Qscan is the most helpful initial evaluation to rule outPE after CXR, ABG and EKG are

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Spiral CT scan of the Chestis helpful if the emboli are large and in the proximal pulmonary artery Spiral CT will be the answer (instead of V/Q scan) if the baseline chest-x ray is abnormal (eg destroyed lung)

 Note:Whenever there is Hypoxia, oxygen is ordered as a Tx

o Try noninvasive ventilation such a 100% non-rebreather mask or BiPAP machine

o If the ABG shows sever hypoxiadespite being on 100% oxygen the intubation is considered  The most typical findings of a PE on ABG sampling are hypoxemia and hypocarbia

 Suspected PE

Notethe problem with CT angiogram is that it can Dx only large emboli, Small emboli can be easity missed 

Suspect choriocarcinoma

in any postpartum women who presents with SOB and

hemoptysis The next step  chest x-ray, pelvic exam, and beta-hCG

DVT

 Patients with DVT in whom anticoagulation is contraindicated require placement of IVC filter for the prevention of pulmonary embolism

 Compression stockings do NOT have any role in the prevention of PE in patients with DVT. They reduce the incidence of venous thrombosis in postsurgical patients by ↓ venous stasis

 Once the Dx of DVT is made by diagnostic testing,next step is to start treatment with anticoagulants unless they are contraindicated.

 DVT is not a clinical diagnosis and therefore all suspected cases of DVT should be evaluted with noninvasive testing and the test of choice for this purpose is compression US.

 Don’t start Tx till prove Dx(because we have only DVT not PE).

 Impedence plethysmographyis the study of choice for recurrent DVT(more specific)

o It becomes normal faster than compression US after an episode of DVT that makes it superior

to compression US for recurrent DVT

Nocturnal sleep apnea

 Noctunal pulse oximetryis used for diagnosing nocturnal desaturation, especially in patients with sleep apnea

 These patients wiII benefit from nocturnal oxygen administration in the form of CPAP

ARDS

 The earliest sign is often tachypnea followed by dyspnea The physical exam and chest x-ray are usually normal initially

 In ARDS, it is best to keep the patient on the dry side and avoid fluid overload  Therefore, most ARDS patients receive diuretics to help decrease the fluid overload

 All patients with ARDS have daily chest x-rays and are weighed daily t o monitor the fluid balance  ↑ TV beyond the recommended 8-10 ml/kg does not help with oxygenation and may in fact ↓

respiratory compliance

 Know the three major complications of too high a PEEP :

o Alveolar damage, o Tension pneumothorax o Ventricular failure

 Pulmonary HTN is very common in ARDS and it occurs as a result of hypoxemic vasoconstriction of pulmonary vasculature

 PCWP is normal in ARDS and it is the most important differentiating point between ARDS and cardiogenic pulmonary edema .It is usually <15 mmHg in ARDS while it is >18 mmHg in cardiogenic pulmonary edema

Criteria for ARDS diagnosis is

1- PCWP< 18 mmHg favors ARDS over cardiogenic pulmonary edema 2- PaO2 to FiO2 ratio of 200 mmHg or less, regardless of the level of PEEP 3- Diffuse, bilateral infiltrates on chest-X ray

This question is based on simple physiology It is expected in USMLE When PEEP is increased, its major drawback is a decrease in cardiac output

Patients who are maintained on PEEP should be monitored with a Swan-Ganz catheter.

To counteract the

effects

of PEEP on cardiac output, some physicians may elect to use inotropic agents or more fluids

Because PEEP increases the intrathoracic pressure, it does slightly increase the central venous pressure This has no significant affect on the patient

Postoperative patient

who presents with dyspnea and tachypnea. one has to exclude: a. MI,

b. PE,

c. pneumonia d. ARDS

Goodpasture and hemisiderosis

 Both patients with IPH(Idiopathic pulmonary hemosiderosis) and Goodpasture’s have hemoptysis (more copious in IPH), iron deficiency anemia and signs of respiratory compromise

 In both cases sputum stain may show iron in the form of hemosiderin and CXR may be abnormal  IPH is more common in young children

 Serologic assays for measurement of AGBMAbs further help in confirming the Dx and monitoring t reatmen t

Wagner

 Note:Fiberoptic bronchoscopy with transbronchial biopsy is not useful in the Dx , however a

thoracoscopic lung biopsy will reveal the full range of pathology of the condition but is not favored as a diagnostic procedure.

 Skin biopsy findings are usually non-specific hence not useful in the diagnosis A deep punch or incisional biopsy demonstrates vasculitis and granulomas

Alveolar proteinosis

 characterized by accumulation of phospholipid rich material in the alveoli probably due to impaired clearance

 Its cause is unknown and it presents with dyspnea and dry cough

 CXRshows bilateral alveolar infilterates

 PFTRLD

 Lung Bx wiII confirm the diagnosis by showing PAS positive material

 Total lung bronchoalveolar lavage is effective treatment of this disoroer. (suck them up …………)

 Corticosteroids are of no benefit in this disease

Hemoptysis

 A case of massive hemoptysis is a medical emergency

 Massive hemoptysis is defined as hemoptysis of >600 ml of blood per 24 hrs

 Most of the times the volume is not measured; therefore any suspicion of massive hemoptysis based up on history needs to be treated as an emergency.

 RIGID BRONCHOSCOPY is the initial intervention of choice in massive hemoptysis because it allows for rapid visualization of the bleeding site and it allows for control of bleeding through laser cautery or other interventions

 Flexible bronchoscopy is used in the diagnostic aspects of hemoptysis and it is not a good choice for emergency management of hemoptysis

 Because of its small lumen it cannot provide much scope for interventions

 Chest X-ray and CT scan are not ideal choices because of the emergency of the situation

Mediastinal mass

 Ant. mediastinal mass + ↑AFP & HCG indicates Nonseminomatous tumor

 Txcan be started evenwithout a tissue biopsy.

 Non-seminomas can be Tx with cis platinum based multi agent chemotherapy These tumors are

very aggressive and in the majority of patients grow to very large size

“Prevention is better than the cure”

Always remember the right time when a common vaccine is given whether it is a child or an adult. This is big in USMLE

 People above 65 years of age should receive pneumococcal vaccine

Idiopathic Interstitial Fibrosis

 IPF is a Dx of exclusion

 best treated with steroids

Most patients will have a positive response in the first six months but they fail to have sustained response

 The shortage of donors has almost eliminated the majority of these patients from transplantation

 ↓ in diffusing capacity does not relate very well with the severity of disease



 Alveolar fibrosis causes ↑ elastic recoil and as a result FEV1/FVC ratio may be ↑… (fibrosis)

 A-a gradient is a useful measure of oxygenation It is increased in interstitial lung diseases due to poor oxygenation

Systemic sclerosis

Note:diffuse SSc Pulmonary HTN and Lung Fibrosis (they have renal a. involvement) BUTLimited SSc (crest synd) Pulmonary HTN only. NO Interstitial lung dz. (no renal a. involvement)

 The most common underlying mechanism of pulmonary complications is interstitial fibrosis

 It develops in about 40% patients with diffuse disease Pulmonary vascular lesions can develop concornitantty with interstitial fibrosis, but isolated pulmonary HTN without interstitial fibrosis occurs in < 10% of patients

 Aspiration of gastric content with resultant pneumonia due to esophageal dysmotility. is less common than interstitial fibrosis

 The risk of bronchogenic carcinoma is ↑ in patients with systemic sclerosis, but it is not the most common cause of pulmonary complications.

 Restriction of chest movements due to extensive thoracic skin fibrosis is rare

 NoteTx of interstitial lung dz cyclophosphamide.

Pulmonary HTN

It can be classified as follows

1- Pulmonary HTN associated with disorders of the respiratory system, hypoxemia, or both

2- Pulmonary HTN due to pulmonary venous hypertension (left ventricular heart disease, mitral valve disease, or pulmonary veno-occlusive disease)

3- Pulmonary HTN following chronic thromboembolic disease

4- Pulmonary arterial HTN (primary pulmonary hypertension, pulmonary hypertension associated with vasculopathy)

5- Pulmonary HTN due to disorders directly affecting the pulmonary vasculature (pulmonary capillary hemangiomatosis)

Chronic cough : nassar

 Cough can be a presenting symptom of GERD

 postnasal drip, is the number one cause of chronic cough in nonsmokers

 note endoscopy is the most sensitive investigation for establishing the Dx of GERD

 The next best step patient is a 24-hour pH recording

Occupational lung Disease

Bird Fanciers lung

 a form of EAA caused by inhalation of bird’s antigens

 initiated and worsened by exposure to organic antigens or haptens.

 avoidance of antigen exposure the most effective Tx (sell your pigons jerk)

 repeated exposure will cause progressive lung damage

 Systemic corticosteroids severe acute symptoms or significant lung dysfunction o significant improvement clinically and functionally

 Inhaled steroids may prove to be useful for prevention or treatment of recurrent disease, but they are usually not used for this purpose

 Inhaled cromolyn No role in the treatment

o used for prevention of acute bronchoconstriction resulting from an acute challenge like in cases of exercise-induced asthma, seasonal asthma

o long-term maintenance therapy in patients of asthma Berylliosis

 Granulamtous pulmonary disease

 high tech industries like aerospace technology, ceramics, electronics Asbestosis

 DxHx of significant exposure + clinical Sx, + radiographic and physiological findings

 A radiographic finding of pleural plaques is the hallmark of asbestos exposure

Obstructive sleep apnea OSA

 The treatment of a mild to moderate disorder usually starts with w eight reduction, avoidance of sedatives and alcohol, and avoidance of supine posture during sleep

 Other treatment modalities include uvulopalatopharyngoplasty and nasal continuous positive airway pressure (CPAP) during sleep

 Tracheostomyis used in patients with a severe disorder, and when all the other treatment modalities have failed

 The clinical clues for diagnosis of this condition are 1) Habitual nighttime snoring

2) Day time somnolence 3) Hypertension

 In severe cases, the patient may develop pulmonary HTN due to chronic hypoxia and 2nd _{right heart} failure

 Once OSA is suspected the investigation of choice is Nocturnal Polysomnography documenting episodes of apnea

 Lateral cephalometry is indicated only.when the patient is scheduled for surgery to relieve the airway obstruction

 Similarly. MRI is used only in the presurgical evaluation of the patient.

 Multiple Sleep Latency Test is used only when the diagnosis is not clear after nocturnal polysomnography.

 It is usually done the day after an inconclusive Polysomnography

Drugs

 NoteBeta agonist MAT (multifocal atrial tachycardia) Ipratropium has low potential for toxicity

Know Theophylline toxicity

 manifests as CNS stimulation (headache, insomnia), GI disturbances (nausea,vomiting), and cardiac toxicity (arrhythmia)

 Factors that influence the metabolism of theophylline. (eg , ciprofloxacin and erythromycin decreases its clearance and raises plasma concentration)

 The exact mechanism responsible for the theophylline toxicity is debated, but may include PDE inhibition, adenosine antagonism, and stimulation of epinephrine release Beta-agonists

 may cause arrhythmia. nervousness, and tremor, but CNS and GI effects are not typical

 Patients who are on high doses of beta-2 agonists may develop hypokalemia and patient should be monitored with daily electrolytes

 The other side affects of beta-2 agonists are tachycardia . tremor, and peripheral edema

"Extremely high yield question for USMLE”

Steroids

 ↓ eosinophils

 Lymphocyte arrest

 ↑neutrophils

o ↑ the bone marrow release

o mobilizing the marginated neutrophil pool

Note::Hypersensitivity reaction is a potential cause of leukocytosis due to hypersensitivity-induced inflammation, but the leukocyte differential neutrophiIia+ eosinophila

Steroids

 In adults, the adverse

effect

of low- dose inhaled corticosteroid are limited to topical problems such as o dysphonia, which occurs in 50 % of patients

o oral candidiasis; symptomatic in less than 5 percent

 High doses of inhaled corticosteroids ↑ systemic absorption and can produce o adrenal suppression,

o cataract formation, o ↓ growth in chiIdren,

o interference with bone metabolism o purpura

 Steroids cause worsening of the GERD symptoms Even if you use steroids in the treatment of bronchial asthma, inhaled steroids are more efficacious and have less systemic effects

Extremely high yield question for USMLEIII

ACEi

 The pathogenesis of the cough is related to an accumulation of the inflammatory or proinflammatory mediators bra dykinin, substance P, t hromboxanes, and prostaglandins

 If the cough is disturbing, ACE inhibitor therapy should be discontinued.

 Only if the cough persists after the discontinuation of ACE inhibitor therapy,CXR Kinins are degraded by ACE

It is caused by an accumulation of kinins, and possibly by the activation of the arachidonic acid pathway

N-acetylcysteine Anti sitamol

 is used to treat patients who have very viscous secretions

 The agent reduces the viscosity and prevents airway plugging

 N-acetylcysteine is a mucolytic agent, which is no longer used in exacerbation of COPD, as they are even implicated in worsening bronchospasm

 has a few indications like o CO poisoning,

o treatment of bends after deep sea diving, o few chronic infections

ASA

Aspirin Sensitivity Syndrome High yield Q

Clues to correct DxASA ingestion , Persistant nasal blockage ,and episodes of bronchoconstriction.

PathogenesisPseudoAllergic Reaction. an exaggerated release of vasoactive and inflammatory mediators in susceptible individual .

ASA is COX1-2 inhibitor

↑5-lipoxygenase

pathway 

↑ leukotrines

and change PG/LT balance trigger characteristic reaction ( bronchoconstriction , polyp formation ) in susceptible individual.

LT inhibitors are gaining popularity in the Tx of this condition

. (DOC)

Other commonly used Tx modalities include topical steroid and ASA

desensitization

Tx.

Miscellaneous

 Shift of the endotracheal tube or into a main bronchus or mucous plugging could cause a collapsed lung However, in that case, the main problem is with oxygenation and the circulatory findings are secondary



BAL is

>

90% effective in Dx PCP

in HIV posi

tive patients, especially when CD4 count is <200. o non-specific in diagnosing:

 sarcoidosis  asbestos industry

 37-year-old female with positive RF.

 Increased ventilatory rate in patients on mechanical ventilation leads to auto PEEP and it can be

corrected by reducing the ventilatory rate (PEEP ↑intrathoracic pressure ↓ venous return ↓CO).  Always consider candida albicans as a cause of infection in a patient with uncontrolled DM do KOH

preparation

Pleurocentisis

The aspirated fluid should always be analyzed for 1. the protein content

o does not determine the need for a chest tube 2. gram stain,

3. LDH

o does NOT indicate if an empyema has occurred (MI,cirrhosis,ischemia) 4. cell count,

o ↑PMNchest tube

o ↑lymphoNOT (malignance,TB) 5. cytology (rule out malignancy),

6. glucose levels

7. pH

o Low pH <7.2is almost always indicative of an empyema and indicates chest tube Note: non-infectious causes generally clear,

infectious,cloudy

Hemorrhagic effusions are bloody in nature, Ruptured thoracic duct milky white effusion

Which one of the following laboratory tests on the pleural fluid is currently thought to be most helpful in determining the need for chest tube placement in parapneumonic effusion?