|
|
(16 intermediate revisions by 3 users not shown) |
Line 1: |
Line 1: |
− | {{review}}
| + | #REDIRECT[[:Category:Lungs - Circulatory Pathology]] |
− | | |
− | {{toplink
| |
− | |backcolour = D1EEEE
| |
− | |linkpage =Cardiorespiratory System - Pathology
| |
− | |linktext =Cardiorespiratory System
| |
− | |maplink = Cardiorespiratory System (Content Map) - Pathology
| |
− | |pagetype =Pathology
| |
− | |sublink1=Lungs Degenerative - Pathology
| |
− | |subtext1=LUNGS DEGENERATIVE
| |
− | }}
| |
− | <br>
| |
− | ==Hyperaemia==
| |
− | | |
− | *Localised of diffuse as part of acute inflammation
| |
− | | |
− | | |
− | ==Congestion==
| |
− | | |
− | *Decreased outflow of venous blood
| |
− | *Most commonly caused by left-sided or bilateral cardiac failure
| |
− | **Stagnant blood in pulmonary vessels -> red blood cells move into alveoli and are phagocytosed -> [[Pigmentation and Calcification - Pathology#Haemosiderin|haemosiderin in macrophages]] (heart failure cells)
| |
− | *One-sided in post-mortem hypostatic congestion
| |
− | *Acute pulmonary congestion is seen after barbiturate euthanasia
| |
− | *Leads to pulmonary oedema (below)
| |
− | | |
− | | |
− | ==Pulmonary oedema==
| |
− | | |
− | *Excessive fluid in the lung
| |
− | *Normally, mechanisms are in place to protect the lung from the entry of circulatory fluid into alveolar spaces (See [[Respiratory System General Introduction - Pathology#Lungs|functional anatomy]])
| |
− | *Occurs when exudation of fluid from vessels into interstitium or alveoli exceeds the rate of alveolar or lymph removal
| |
− | *Generally a sequel to or part of congestion or inflammatory process
| |
− | *Generally begins as '''interstitial oedema''' characterised by expansion of perivascular and peribronchial and peribronchiolar fascia and distension of interstitial lymphatics
| |
− | *Only when this interstitial compartment is overwhelmed does fluid flood the airspaces causing '''alveolar oedema'''
| |
− | *Gross pathology:
| |
− | **Heavy wet lungs which do not properly collapse
| |
− | **Subpleural and interstitial tissue distended with fluid
| |
− | **Foamy fluid oozing from the cut surface and airways
| |
− | *Micro pathology:
| |
− | **Pinkish fluid in alveoli and airways in association with air bubbles, and also in dilated lymphatics of the interstitium
| |
− | **Colour of the fluid enhanced in cases where the endothelium is damaged - more protein present
| |
− | **In slowly developing cases, macrophages contain haemosiderin
| |
− | *The major causes of pulmonary oedema are:
| |
− | **Increased capillary or type I epithelial permeability caused by
| |
− | ***Systemic toxins
| |
− | ***Shock
| |
− | ***Inhaled caustic gases
| |
− | **Increased capillary hydrostatic pressure ('''cardiogenic oedema''' - left-sided or biventricular heart failure, sympathetic stimulation in acute brain damage)
| |
− | **Decreased plasma oncotic pressure (hypoalbuminaemia)
| |
− | **Overloading in excessive fluid therapy
| |
− | **As part of inflammatory process
| |
− | | |
− | | |
− | ==Pulmonary haemorrhage==
| |
− | [[Image:Pulmonary haemorrhage.jpg|right|thumb|100px|<small><center>Pulmonary haemorrhage (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
− | *Potential sequel of septicaemias, bleeding disorders, disseminated intravascular coagulation, and severe congestion, severe acute inflammation, "back splashing" at slaughter (aspiration of blood)
| |
− | *[[Exercise Induced Pulmonary Haemorrhage - Pathology|'''Exercise-induced pulmonary hemorrhage''' (EIPH)]] occurs commonly in horses during racing or training
| |
− | **Shows as [[Respiratory System Clinical Signs - Pathology#Epistaxis|epistaxis]]
| |
− | **Undetected in many horses
| |
− | **Haemorrhage is dorsocaudal, large brown areas
| |
− | **Micro - alveolar haemorrhage, macrophages containing [[Pigmentation and Calcification - Pathology#Haemosiderin|haemosiderin]], mild interstitial fibrosis
| |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | ==Embolism, thrombosis and infarction==
| |
− | [[Image:Pulmonary infarction.jpg|right|thumb|100px|<small><center>Pulmonary infarction (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] | |
− | [[Image:Segmental pulmonary infarction.jpg|right|thumb|100px|<small><center>Segmental pulmonary infarction (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
− | | |
− | *Lungs are strategically situated to catch emboli carried in venous blood
| |
− | *Because the lung is supplied by both pulmonary and bronchial arteries and has extensive collateral channels, infarction usually does not follow embolism or thrombosis unless pulmonary circulation is already compromised
| |
− | *In animals, greatest risk comes from:
| |
− | **'''Tumor emboli'''
| |
− | ***From e.g.: osteosarcoma and haemangiosarcoma in dogs, uterine carcinoma in cattle
| |
− | **'''Septic emboli'''
| |
− | ***From bacterial [[Endocarditis|endocarditis]], jugular thrombophlebitis, [[Hepatic Abscessation|hepatic abscesses]] etc.
| |
− | ***May cause unexpected death if in large numbers
| |
− | ***May develop [[Lungs Inflammatory - Pathology|suppurative pneumonia]] -> [[Lungs Inflammatory - Pathology#Pulmonary abscesses|pulmonary abscesses]], [[Arteritis|arteritis]], [[Thrombosis - Pathology|thrombosis]]
| |
− | *Pulmonary infarcts usually occur when there is embolisation or thrombosis during general circulatory collapse or passive congestion of heart failure
| |
− | *Pulmonary thromboembolism is a sequel to in cattle to large emboli from liver abscesses close to the vena cava
| |
− | **Death may ocur due to massive haemorrhaging into lung tissue
| |
− | *Parasites (e.g. [[Respiratory Parasitic Infections - Pathology#Dirofilaria immitis|''Dirofilaria immitis'']], [[Respiratory Parasitic Infections - Pathology#Angiostrongylus vasorum|''Angiostrongylus vasorum'']]) may be responsible
| |
− | *Long-term intravenous catheterisation may cuse thrombi pieces breaking off and lodging in pulmonary vessels
| |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | | |
− | ==Pulmonary hypertension==
| |
− | | |
− | *Caused by '''left-to-right vascular shunts''' or increased resistance of the pulmonary vascular system
| |
− | | |
− | *In animals, it is most commonly a sequel of '''widespread fibrosis in the lung''' or [[Bronchi and Bronchioles Inflammatory - Pathology#Chronic bronchitis|chronic bronchitis or bronchiolitis]] which stimulates hypertrophy in the walls of small arteries
| |
− | *Severe prolonged pulmonary hypertension leads to [[Cor Pulmonale|'''cor pulmonale''']], right-sided heart failure secondary to primary lung disease
| |