Medicine Flashcards
Heparin side effects?
Heparin induced thrombocytopenia (HIT)
- don’t give warfarin as it decreases amount of anticoagulant protein C worsening pro thrombotic state (HIT causes paradoxical venous and arterial thrombosis)
- use direct thrombin inhibitors instead
- stop heparin immediately if suspected
Diagnosed by anti-PF4 antibodies if high protest probability (80% specific)
Absolute thrombocytopenia or 50%drop, happens in 5-10 days of starting heparin
Hepatosplenomegaly causes?
Infective
Haematological
Metabolic
……
Hernia exam + indications for repair?
?
Jaundice differential?
?? Haemolytic, intrahepatic, obstructive
Stop statins if starting what?
? Macrolides
ABCDE of CHF X-ray
- Alveolar oedema (bats wing)
- Kerley B lines (Interstitial oedema)
- Cardiomegaly
- Dilated upper lobe vessels
- Effusions
Other signs: Peribronchial cuffing (haziness around bronchi or large bronchioles when seen end on, due to increased fluid or thickened bronchial walls - donut sign)
Haziness of vessels - not as well defined due to interstitial oedema
Widened vascular pedicle
Consolidation, air bronchograms
Increased artery to bronchus ratio best seen in the perihilar region (end on) normally larger at hilum at a ratio of 1.35, smaller than bronchi in upper lobes
Dilation of azygous vein
Varieties of pulmonary oedema?
And vascular pedicle
3 principle varieties:
Cardiac
Over hydration
Increased capillary permeability (ARDS - Acute respiratory distress syndrome)
In relation to VPW (vascular pedicle width): note VPW best used as a serial measure, and may increase on rotation to the right
- Normal VPW-cap permeability, acute cardiac failure
- Widened VPW - over hydration/renal failure, chronic cardiac failure
- Narrowed VPW - most common in cap permeability
Virchows triad?
Endothelial injury
Stasis/turbulent flow
Hypercoaguability
Factors predisposing to thrombosis
Clotting tests?
- APTT activated partial thromboplastin time - measures intrinsic (contact) pathway
Factors I, II, V, VIII, IX, X, XI, XII (1, 2, 5, 8, 9, 10, 11, 12)
notably: Deficiencies In VII or XIII don’t show on APTT. - Prothrombin time (PT)
Extrinsic (tissue factor) pathway
Factors I, II, V, VII, X, (1, 2, 5, 7, 10)
2.ii INR international normalised ratio
Standardised value derived from PT. 0.8-1.2 is N, aim for 2-3 if anti coagulating
- Thrombin Time (TT) aka Thrombin Clotting Time (TCT)
Adds thrombin to plasma and measures clotting, prolonged in fibrinogen abnormality or deficiency and heparin
Note: factor I is fibrinogen, II is prothrombin
Prolonged APTT?
Anticoagulants:
-Heparin, Warfarin
-Antiphospholipid antibodies esp Lupus anticoagulant - note: causes paradoxical thrombosis, binds to prothrombin and activates it
Factor deficiencies eg:
- haemophilia A and B (VIII or IX) hereditary genetic disorder, X chromosome sex linked, recessive, so much more likely in men. A is most common (1/5-10,000 male live births) B(1/20-35000 male live births)
- von willebrand disease (rarely - only when causing VIII deficiency. vWF normally bound to VIII and cleaved by thrombin, degrades rapidly when not bound to vWF)
- sepsis (consumes factors - DIC)
- antibodies against factors (factor inhibitors)
Note: haemophilia C is factor XI deficiency, non sex linked, more common in Jews, otherwise rare
Anti phospholipid syndrome symptoms/signs?
(Autoimmune disease - lupus anticoagulant and anti cardiolipin antibodies are the 2 possible antiphospholipid antibodies)
- Thrombosis (most common are: arterial -> stroke, venous -> DVT in legs)
- Pregnancy related complications
Still birth, recurrent miscarriage, IUGR, preterm birth, pre eclampsia. frequently caused by placental infarction
Other common findings are:
low platelet count, heart valve disease, livedo reticularis
Also associated with headaches, migraines, oscillopsia
Treatment:
Aspirin and warfarin(heparin if pregnant)
Primary or secondary to autoimmune disease (SLE mostly)
Can cause rapid multiorgan failure due to generalised thrombosis in rare cases - CAPS (Catastrophic…)
Differentiating causes of prolonged APTT?
Mixing tests with normal plasma
Will correct if factor deficiency
- ->If doesn’t correct then an “inhibitor” is present:
- Heparin
- Antiphospholipid antibodies (lupus anticoagulant or anticardiolipin)
- coagulation factor specific inhibitors
Corrected with mixing?
- I, II, V, VIII, IX, X, XI, XII
- rarely vWF if causing low VIII level
Prolonged PT?
Factor deficiencies:
- Warfarin or other vitamin K deficiency, malabsorption
- poor factor VII synthesis eg liver disease
- Consumption eg DIC
Tests: Factors I, II, V, VII, X, so deficiencies of these will all prolong PR
Note: early liver failure prolongs PR only, end stage prolongs APTT as well
Transfusion reactions
Haemolytic Febrile non hemolytic Allergy Infection Transfusion related acute lung injury
