Page 97 - Concise Pathology for Exam Preparation ( PDFDrive )

82 SECTION I General Pathology

o
Breakdown fat globules into free fatty acids
f

Toxic injury to endothelium by free fatty acids

Platelet activation and recruitment of granulocytes

Production of free radicals, proteases and eicosanoids
Vascular damage
FLOWCHART 4.8. Biochemical basis of cellular injury in fat embolism.

Clinical Features

Clinical manifestations appear within 1–3 days trauma and include
of
• �Tachypnoea, dyspnoea and tachycardia (pulmonary insufficiency)
• �Irritability, restlessness, delirium and coma (neurological effects)
to
• �Diffuse petechial rash nondependent areas (due thrombocytopaenia resulting from
in
platelet consumption)
• �Anaemia (due to aggregation of RBCs and microangiopathic haemolysis)

Q. Write briefly on systemic thromboembolism.
of
Ans. Majority systemic emboli originate from intracardiac mural thrombi (two-thirds
from left ventricular wall infarcts; one-fourth from left atrial dilatation and fibrillation and

the remaining from aortic aneurysms, atheromas, valvular vegetations and paradoxical

emboli). About 10–15% are ambiguous origin. Venous emboli mostly travel the

to

of

or
lungs; arterial emboli travel different sites, most commonly lower extremities brain.
to
Q. Write briefly on amniotic fluid embolism.
of

a

Ans. Amniotic fluid embolism cause maternal morbidity during labour and im-
is
to
of
mediate postpartum period, and has mortality up 20–40%.
a
Pathogenesis

Caused by infusion amniotic fluid with all its contents (fetal cells and debris) into

of

to
in
of
or
maternal circulation due tears placental membrane rupture uterine vessels.
Clinical Findings
• �Sudden respiratory distress
• �Deep cyanosis
• �Hypotensive shock
• �Seizures, convulsions, coma and death
Microscopic Features
• �Pulmonary microcirculation shows fetal skin, squamous cells, lanugo hair and fat from
vernix caseosa, mucin from fetal respiratory tract GIT.
or
is
• �There pulmonary oedema and diffuse alveolar damage and haemorrhage.
Causes of Death
of
• �Mechanical blockage pulmonary circulation
• �DIC
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