Pulmonary Embolism Flashcards
when does PE occur
PE occurs when a deep vein thrombosis migrates to the pulmonary arterial tree
types of PE
massive pe
sub- massive pe
low risk pe
non- massive pe
massive pe
acute PE with obstructive shock or SBP <90 mmHg
sub- massive pe
acute PE with obstructive shock or SBP <90 mmHg
pathophysiology
Effects are proportional to the rapidity and degree of obstruction
Increased PVR -> RVF -> obstructive shock
Increased alveolar dead space -> V/Q mismatch -> pulmonary vasoconstriction to optimize gas exchange
Pulmonary infarction
Chronic pulmonary hypertension can ensue
(PVR= pulmonary vascular resistance; RVF= right ventricular failure)
history
May be asymptomatic
SOB
Pleuritic chest pain
Apprehension
Cough
Haemotypsis
Leg pain
Collapse = massive PE
Acute cardiovascular collapse
examination
Pale, mottled skin
Tachypnoea
Tachycardia
Signs of DVT
Hypotension
Altered LOC
Elevated JVP
Parasternal heave
Loud P2
Central cyanosis
risk factors
major- SLOMP
Surgery – major abdominal/pelvic, hip/knee replacements, post ICU
Lower limb problems – #, varicose veins
Obstetrics – late pregnancy, C/S, puerperium
Malignancy – abdominal/pelvic, advanced/metastatic
Mobility – hospitalization, institutional care
Previous VTE (venous thromboembolism)
risk factors
Minor COM
Cardiovascular – congenital heart disease, CHF, HT, superficial venous thrombosis, CVL
Oestrogens – OCP, HRT
Miscellaneous – COPD, neurological disability, occult malignancy, thrombotic disorder, long distance travel, obesity, other (IBD, nephrotic syndrome, dialysis, myeloproliferative disorders, paroxysmal nocturnal haemoglobinuria, Bechet’s disease)
thrombophilia
-Factor V Leiden mutation
-Prothrombin gene mutation
-Hyperhomocysteinaemia
-Antiphospholipid antibody syndrome
-Deficiency of antithrombin III, protein C or protein S
-High concentrations of factor VIII or XI
-Increased lipoprotein (a)
-> test in those < 50years with recurrent or a strong FHx
how to assess severity
severity is judged by assessing the haemodynamic status of the patient.
severity assessment of massive pe
recognised by right ventricular dysfunction and haemodynamic compromise not due to a cause other than PE
severity assessment of sub- massive pe
is recognised by right ventricular strain or myocardial necrosis without haemodynamic compromise
severity assessment of non- massive PE
is not associated with right ventricular strain, myocardial necrosis or haemodynamic compromise
definition of hypotension
systolic blood pressure of <90 mmHg or a pressure drop of >40 mmHg for >15 min
