Seminars for the 5th year students
Seminar 11
Prof. Jiří Horák
Lung Diseases (3)
Pneumoconioses
Def: lung diseases produced by inhalation of inorganic dust
Substance
fibrogenicity
occupation
I. Fibrous minerals
asbestos
high
asbestos mining, insulation
talc
high
talc mining and milling
fiberglass
low
insulation
silica
high
mining, sandblasting
coal
low
mining
iron
low
mining, refining, welding
aluminium
uncertain
dtto
beryllium
high
mining, industry
tin
low
smelting
II. Nonfibrous minerals
III. Metals
Asbestos - a fivefold increase in the rate of bronchogenic carcinoma
among nonsmoking asbestos workers. Malignant mesotheliomas of the
pleura and peritoneum are also associated with smoking.
Simple pneumoconiosis consisting of a fine, diffuse, reticulonodular
pattern seen on chest roentgenogram and the development of a productive
cough occur in 5% of coal workers.
Physiologic impairment, when present, is slight.
Silica exposure - silicosis develops after at least 20 years of exposure,
although it can develop in less than 5 years with intense exposure.
X-ray: changes range from small diffuse nodules with minimal hilar node
enlargement to large nodules, predominantly in the upper lobes, which
vary from about 1 cm to conglomerate masses (progressive massive
fibrosis). Eggshell calcification of the hilar nodes.
Modification by smoking or superinfection with mycobacterial disease.
1/6
Seminars for the 5th year students
Seminar 11
Prof. Jiří Horák
Th: no specific treatment, removal from the offending environment,
search for mycobacterial disease, cessation of smoking, the use of oxygen
to treat complicating cor pulmonale
Hypersensitivity pneumonitis (extrinsic allergic alveolitis)
caused by abnormal sensitivity to some organic agent
4 - 6 hours following exposure in a sensitized subject there is the onset of
cough, dyspnea, fever, and malaise. Wheezing is usually absent.
Phys: diffuse crackles
X-ray: nodular or reticulonodular infiltrates with relative sparing of the
apices.
In most cases, these symptoms gradually resolve but recur on subsequent
exposure.
Repeated exposure - development of pulmonary fibrosis and restrictive
lung disease.
Hypersensitivity pneumonitis
antigen
source
disease examples
Thermophilic bacteria
moldy hay
farmer‘s lung
Bacillus subtilis etc.
water
humidifier lung
fungi
moldy organic material, maple bark-stripper‘s
water
lung
animal protein
bird droppings
pigeon breeder‘s lung
amoeba
water
humidifier lung
Pathogenesis: both immune complex and cell-mediated immune
mechanisms
Th: avoid or remove the offending agent. In acute situations
corticosteroids
Primary pulmonary hypertension
a disease of young adult women.
Pathogenesis: extrinsic or intrinsic stimulus in genetically predisposed
individuals. Inflammatory or immunologic injury to the pulmonary
endothelium results in an imbalance of locally produced vasoconstrictor
2/6
Seminars for the 5th year students
Seminar 11
Prof. Jiří Horák
(thromboxane, endothelin) and vasodilator (prostacyclin) factors pulmonary thrombosis in situ.
Clin: progressive dyspnea and exercise limitation, syncopes, fatigue,
chest pain, cor pulmonale.
Dg: right heart catheterization
Th: chronic anticoagulation, high doses of calcium channel blockers,
prostacyclin, inhaled nitric oxide, combined heart-lung transplantation
Prognosis: 20% survive 3 years
Common drug-induced lung disease
drug
dose relation
appearance
I. Cancer chemotherapeutics
bleomycin
both acute and dose dependent pulmonary fibrosis
busulfan
> 600 mg
pulmonary fibrosis
chlorambucil
>2g
pulmonary fibrosis
methotrexate
none
pneumonitis
II. Analgesics and hypnotics
aspirin
serum level > 45 mg/dl pulmonary edema
ethchlorvynol,
overdose
pulmonary edema
propoxyphene HCl, heroin
opiates and other
chronic i.v. abuse
psychotropic drugs
pulmonary fibrosis
and vasculitis
III. Antibiotics
nitrofurantoin
acute
hypersensitivity
pneumonitis
sulfonamides
chronic
pulmonary fibrosis,
Löffler‘s syndrome
Sarcoidosis
Def: systemic disease of unknown etiology characterized by noncaseating
granulomas found diffusely throughout the body. It occurs most
commonly in the 20s and 30s.
3/6
Seminars for the 5th year students
Seminar 11
Prof. Jiří Horák
Pathogenesis: T-cell activation
Lab: increased percentage of lymphocytes in bronchoalveolar lavage fluid
is a marker of alveolitis
Pathol: organs involved: lungs, skin, lymph nodes, liver, spleen, eyes,
joints, CNS, muscles
Clin: lungs - progressing cough and shortness of breath, pulmonary
fibrosis with respiratory insufficiency
Löfgren‘s syndrome - fever, arthralgias, bilateral hilar adenopathy,
erythema nodosum
skin - lupus pernio (papules, plaques and subcutaneous nodules of the
nose) or plaques
CNS - cranial nerve palsies, diabetes insipidus, subacute meningitis
joints – arthritis
eyes – uveitis, conjunctivitis, retinal involvement, keratoconjuntivitis
sicca (when lacrimal and salivary glands are involved) → steroid Th
peripheral lymphadenopathy and/or splenomegaly
granulomatous hepatitis
heart - arrhythmias, conduction disturbances
hypercalcemia with nephrocalcinosis or nephrolithiasis
Dg: transbronchial biopsy during bronchoscopy, X-ray, liver biopsy,
Kveim test. Pulmonary function tests: restriction + decreased diffusion
capacity. Depressed tuberculin reaction.
Th: corticosteroids, ketoconazole for hypercalcemia
Prognosis: complete resolution of symptoms and chest radiographic
changes within 1 - 2 years. Persistent mild abnormality in a minority of
patients. In 10% severe progressive disease with pulmonary fibrosis or
significant extrapulmonary involvement.
ARDS (Adult Respiratory Distress Syndrome; non-cardiogenic
pulmonary edema)
ARDS can occur as the result of direct lung injury (e.g. aspiration of
gastric acid contents, viral pneumonia) or as part of MODS.
Conditions associated with ARDS
- shock (traumatic, septic, etc.)
4/6
Seminars for the 5th year students
Seminar 11
Prof. Jiří Horák
- infection (pneumonia – viral, bacterial, pneumocystis carinii;
G- sepsis)
- trauma (fat emboli, head injuries, lung contusion)
- aspiration (gastric contents, fresh or salt water)
- drug overdose (narcotics, barbiturates)
- metabolic disorders (poancreatitis, uremia)
- inhaled toxins (O2, smoke, corrosives)
- blood disorders (DIC, massive blood transfusions)
- miscellaneous (radiation, eclampsia, raised intracranial pressure,
seizures, high altitude)
The Multiple Organ Dysfunction Syndrome (MODS): the presence of
altered organ function in an acutely ill patient such that homeostasis
cannot be maintained without intervention. Microcirculation is the
primary target of injury.
Pathogenesis:
alveolar-capillary membrane injury → ↑ permeability of endothelium and
epithelium → interstitial and alveolar edema → ↓ surfactant
alveolar and airway
filling and closure
↓ compliance, intrapulmonary shunting
hypoxemia
ARDS – diagnostic criteria:
- proper clinical setting (pneumonia, shock etc.)
- PaO2 to FiO2 ratio is ≤ 200 on FiO2 > 0.60 (FiO2 = fractional
concentration of inspired O2)
- diffuse pulmonary infiltrates on chest radiography
- pulmonary artery wedge pressure ≤ 18 mm Hg (normal left atrial
pressure)
5/6
Seminars for the 5th year students
Seminar 11
Prof. Jiří Horák
Th: - Swan-Ganz catheter into the pulmonary artery
- intubation and mechanical ventilation (oxygenation with the use of
high tidal volumes and PEEP)
- maintaining fluid balance (PAWP 6 – 8 cm H2O)
- sepsis is the commonest cause of death → antibiotics
- corticosteroids are not indicated
Outlook: 50 – 70% mortality, nearly 100% mortality in ARDS as a part
of MODS
Of those who survive most recover normal lung function
------------------------
6/6