📖 General Pathology
Pulmonary embolism
General PathologyPulmonary embolism
A pulmonary embolism (thromboembolism) occurs when a blood clot, generally a venous thrombus, becomes dislodged from its site of formation and embolizes to the arterial blood supply of one of the lungs.
Clinical presentation
Signs of PE are sudden-onset dyspnea (shortness of breath, 73%), tachypnea (rapid breathing, 70%), chest pain of "pleuritic" nature (worsened by breathing, 66%), cough (37%), hemoptysis (coughing up blood, 13%), and in severe cases, cyanosis, tachycardia (rapid heart rate), hypotension, shock, loss of consciousness, and death. Although most cases have no clinical evidence of deep venous thrombosis in the legs, findings that indicate this may aid in the diagnosis.
Diagnosis
The gold standard for diagnosing pulmonary embolism (PE) is pulmonary angiography
An electrocardiogram may show signs of right heart strain or acute cor pulmonale in cases of large PEs
In massive PE, dysfunction of the right side of the heart can be seen on echocardiography, an indication that the pulmonary artery is severely obstructed and the heart is unable to match the pressure.
Treatment
Acutely, supportive treatments, such as oxygen or analgesia
In most cases, anticoagulant therapy is the mainstay of treatment. Heparin or low molecular weight heparins are administered initially, while warfarin therapy is given
Cor pulmonale
General PathologyCor pulmonale
a failure of the right side of the heart. It is caused by prolonged high blood pressure in the right ventricle of the heart, which in turn is most often caused by pulmonary hypertension - prolonged high blood pressure in the arteries or veins of the lungs. People with heart disease, or lung diseases such as cystic fibrosis, are at greater risk.
Pathophysiology
There are several mechanisms leading to pulmonary hypertension and cor pulmonale:
Pulmonary vasoconstriction
Anatomic changes in vascularisation
Increased blood viscosity
Primary pulmonary hypertension
Causes
Acute:
• Massive pulmonary embolization
• Exacerbation of chronic cor pulmonale
Chronic:
• COPD
• Loss of lung tissue following trauma or surgery
Amyotrophic lateral sclerosis
General PathologyAmyotrophic lateral sclerosis (Lou Gehrig’s disease)
a. Characterized by the rapid degeneration of motor neurons in the spinal cord and corticospinal tracts.
b. More common in men in their 50s.
c. Clinically, the disease results in rapidly progressive muscle atrophy due to denervation. Other symptoms include fasciculations, hyperreflexia, spasticity, and pathologic reflexes. Death usually occurs within a few years from onset, usually by respiratory failure or infection.
Q Fever
General PathologyQ Fever
An acute disease caused by Coxiella burnetii (Rickettsia burnetii) and
characterized by sudden onset of fever, headache, malaise, and interstitial
pneumonitis.
Symptoms and Signs
The incubation period varies from 9 to 28 days and averages 18 to 21 days. Onset
is abrupt, with fever, severe headache, chills, severe malaise, myalgia, and,
often, chest pains. Fever may rise to 40° C (104° F) and persist for 1 to > 3
wk. Unlike other rickettsial diseases, Q fever is not associated with a
cutaneous exanthem. A nonproductive cough and x-ray evidence of pneumonitis
often develop during the 2nd wk of illness.
In severe cases, lobar consolidation usually occurs, and the gross appearance of
the lungs may resemble that of bacterial pneumonia
About 1/3 of patients with protracted Q fever develop hepatitis, characterized
by fever, malaise, hepatomegaly with right upper abdominal pain, and possibly
jaundice. Liver biopsy specimens show diffuse granulomatous changes, and C.
burnetii may be identified by immunofluorescence.