Download Bleeding in Surgery: What are responsible for hemostasis [stoppage

Bleeding in Surgery:
On going to surgery bring knife and cut the skin what will happen?
Bleeding, From where? Bleeding immediately from venules, arterioles and capillaries.
If we left this bleeding when it stops? This is called Bleeding time [8-9 min to stop by itself]
Now, after 1-2 hours if there is bleeding again that mean Coagulation system failure.
What are responsible for hemostasis [stoppage of bleeding] are the platelets in the first line
followed by the cascade of the extrinsic and the intrinsic factors that need hours to occur.
The main factors in bleeding are the Platelets and the coagulation systems.
Blood Movement inside the artery or the vain:
The movement of the blood is Laminar
[like a bullet movement] or Centrifugation
movement.
By mass and density differences and by
centrifuging the least density will be the
outermost which is the plasma followed by
the platelets and high density will be in the
center such as proteins, RBC…
Principle of Clot formation
The charge of blood is negative (-ve).
The charge of endothelium of the vascular
system is also negative (-ve).
So the blood will never precipitate on the endothelial wall [in normal situation].
In case of blood vessel injury or inflammation the charge of the endothelium
immediately will become positive (+ve) and nearest substances to the endothelium
are the platelets and the plasma.
The platelets will adhere to the cut edges of the vessel and release chemicals to attract even
more platelets to form Blood Clot. [This is the first defense against injury, Clotting]
Classification of bleeding disorders:
I.
Due to defects of the blood vessels.
1. Vascular purpura:
a. Infections
b. Chemical agents
c. Metabolic purpura
d. Scurvy (vit. C deficiency)
e. Anaphylactoid purpura.
2. Hereditary hemorrhagic telangiectasia: [in Internal Medicine]
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II.
Due to disorders of platelets.
1. Reduced number of platelets:
a. Idiopathic thrombocytopenic purpura (ITP)
b. secondary thrombocytopenic purpura which is seen in:
Blood Dyscrasias [disorder] as in Leukemia and aplastic anemia.
Side effects of drugs as in sulphonamide, quinidine.
Systemic lupus erythematosis SLE.
Acute infections as in infectious mononucleosis and Rubella
Extensive hemangiomas in infants
Massive blood transfusion.
2. Increased number of platelets: thrombocythemia
Excessive platelet count with some dysfunction
Causes severe GIT and post operative bleeding
Condition occurs in the rare disease like hemorrhagic thrombocythemia.
3. Defective platelets: Hereditary and Acquired thrombasthenia [asthenia = weakness ]
The count is normal but the function is defective.
Seen in Glanzman disease (Platelet aggregation)
Seen in Renal and Hepatic Failure and in macroglobulinemia.
Platelet adhesion as in Von Willebrand’s syndrome and BernardSoulier disease.
Drugs play v.imp role: Aspirin and NSAIDs, they prevent the
coagulation and the clotting therefore we have to stop the intake of
these drugs for 2 week or 12 days at least.
In Von Willebrand’s syndrome there is defective in 1blood vessel, 2platelets, and in the
3
coagulation system
Summery of the common causes:
Thrombocytopenia results from ITP, hepatic diseases, tumors, blood transfusion, DIC
(disseminated intra-vascular coagulation), drugs
Impaired platelet adhesions results from Uremia and drugs
Impaired platelet aggregation results from Uremia, hepatic diseases, extracorporal
circulation, leukemia and drugs.
Extracorporal Circulation: Circulation of the blood outside the body, as through a heart-lung machine
or artificial kidney.
III.
Due to defects of the clotting mechanism:
1. Hereditary:
a. Hemophilia (factor VIII deficiency) or hemophilia A.
b. Christmas disease (factor IX deficiency) or hemophilia B.
c. Von Willebrand’s disease.
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2. Acquired
Deficiency of vit K dependant coagulation factors [most common]
Oral anticoagulant therapy such as warfarin
Defective coagulation in hepatic diseases.
Tumors, DIC, anticoagulation, massive transfusion.
Coagulation inhibitors as in heparin and lymphomas
Excess fibrinolysis in DIC [diffuse intravascular coagulation]
Vitamin K dependant coagulation factors (II, VII, IX, X (1972)) synthesized in the liver, so
if we block the common bile duct these factors won't go to the intestine to be absorbed [as in
case of obstructive jaundice] .
So patient with obstructive jaundice must take parenteral vitamin K 10mg IM daily because
vitamin K needs 3 days to be effective so we cant give the patient vitamin k and take him
immediately to the OR you have to wait so you have to give it at least for 3 days, but in case
of emergency you have to transfuse plasma proteins or fresh frozen plasma.
Laboratory monitoring of bleeding and coagulation:
Test for Platelets Function:
Coagulation tests:
Test for Platelets Function:
Peripheral platelet count:
Count of 50,000 \ µL or more ensures adequate hemostasis
You are going to read different numbers in different books.
Counts of less than 10,000 \ µL are dangerous and may lead to spontaneous bleeding.
Spontaneous bleeding, as bleeding from the urinary system, GIT system or from any simple trauma there
will be bleeding from the skin. [These are signs of platelets problem]
Prior to surgery, platelet count should be raised to more than 100,000 \ µL
To preserve hemostasis,
Actually this depends on the site of surgery. Ex. If I'm going to do a surgery on a gall bladder where there is
the cystic artery easy to reach [appreciable] I can do the surgery even if the platelet count was 50,000 \ µL
while if I'm going to work on an area which is very difficult to reach such the area behind to tonsils or the
retina or the posterior fossa of the brain in this case I must be sure that the platelets count is high.
Thrombocytosis is diagnosed when count is more than 500,000 \ µL
In case of splenomegaly, all of the platelets stored inside the spleen, so you can’t raise the count of the
platelets because all the platelets will go to the spleen.
Within surgery in a very acute manner open the abdomen [now by laparoscope], locate and ligate the splenic
artery, squeeze the spleen so all the platelets will go back through venous to the circulation so the count will
back to normal..
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Bleeding Time:
[values need to be memorized]
Means assess the ability of platelets to form hemostatic plugs
Bleeding time is usually shorter than 8 minutes
between 8-15 minutes reflects:
› a low plasma level of vWF [usually]
› the use of antiplatelets drugs [Aspirin]
› presence of lupus-like antibodies
› factor XI deficiency
Readings of more than 15 minutes indicate:
› Severe platelet functional impairment.
› Very low levels of vWF.
› Fibrinogenemia.
› Severe factor V deficiency.
Coagulation tests:
PT [Prothrombin Time]
which tests the extrinsic
system [Factor VII and
common pathway]
Normal PT is 12-14 seconds
usually 13 seconds.
PTT [Partial
Thromboplastin Time]
which tests the intrinsic
pathway [Factors XII, XI,
IX, VIII and common
pathway]
Normal PTT is 45 seconds
TT [thrombin time]
Normal TT is 10 seconds
Fibrinogen level:
Normal level is 200-350 mg/dL
Reading the Results
- If PT and PTT are normal, the defect is probably in the vessels or platelets.
- If both PT and PTT are prolonged, the defect is probably in the common pathway
- If PTT is prolonged and PT is normal, the defect is in the intrinsic pathway
- Prolonged PT and normal PTT is rare and indicates deficiency of factor VII
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Blood Transfusion:
Because this topic is important and need at least 3 lectures [we don’t have 3 lectures] we are going to talk just 5
min about transfusion to hit the headlines and the most important info. to read.
Nowadays, Whole blood is only indicated for the treatment of acute hemorrhage.
Nowadays, Fractionated blood is given (Factors, RBCs, Washed WBCs, plasma and platelets)
Because patients sometimes benefit from one blood component but harmed from another
There is no medical or surgical condition that justifies transfusion of less than 2 units of
blood (the body will compensate them in 6 hours)
So indication to blood transfusion should be to more the three units of Blood.
[must read]
Fresh frozen plasma (FFP):
Is prepared from single units of fresh blood and rapidly frozen within 6 hours of
collection
It contains all the constituents of fresh plasma except platelets
FFP kept in a deep freeze at temp – 30 degrees °C. Have a shelf life of one year
FFP is given to patients with failing coagulation as in DIC, deficiency of vitamin Kdependent coagulation factors, over dose of oral anticoagulants, liver diseases, massive
blood transfusion and in congenital deficiency of factors V and X
Cryoprecipitate and single coagulation factor concentrates &
Albumin:
[Given in surgery]
Adverse consequences of blood transfusion
Acute:
Delayed:
- Allergic
- Hemolytic
- Metabolic Disorders
- Respiratory
- Circulatory overload [esp. in children or pt with HF]
- Non-hemolytic febrile reactions.
- Hemostatic
- Sepsis
- Delayed Hemolysis
- Infections: [blood-borne]
[must know]
Bacterial: brucellosis, syphilis.
Helminthic: filariasis.
Protozoal: babesiosis, chagas, trypanosomiasis…
Rickettsial: relapsing fever, rocky mountain.
Viral: HIV 1 & 2, Hepatitis B & C.
Epstein-Bar virus, HTLV1 and 2, yellow fever.
Immediate hemolytic transfusion reaction:
Advice: During transfusion observe the patient at least for 5 min [this is the most critical], because the
patient may develop immediate hemolytic reactions and die instantly.
Clinical presentation in Immediate hemolytic reaction: [in order]
1
2
3
4
5
Burning sensation at the transfusion site followed by Anxiety, Chest pain (tightness), Back pain, headache,
6
7
8
9
10
11
12
13
Dyspnea, Rigors [Chills], Vomiting, Diarrhea, Restlessness, Tachycardia, Hypotension, Shock.
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1.
2.
3.
4.
5.
Treatment:
Stop transfusion immediately.
Give Hydrocortisone 100-200 mg I.V.
Anti-histamine (chlorpheneramine 10mg) I.V.
Intravenous fluid to maintain the blood volume and urinary flow.
In case of intravenous coagulation give Heparin.
Delayed hemolytic transfusion reaction:
Occurs 1-3 weeks after transfusion.
Clinical presentation in Delayed hemolytic reaction:
Patient comes with Urticaria [due to Plasma proteins] esp. in people with IgA deficiency, jaundice, fever,
aneima, arthralgia and myalgia [muscle pain].
Treatment: None in required just observation.
Non-hemolytic febrile transfusion reaction: [Transfusion pyrexia]
Transfusion of infectious diseases: [Should know]
Transfusion reactions associated with plasma proteins: [Urticaria, esp. IgA deficiency]
Transfusion of infectious diseases:
Transfusion of bacteria and parasites as malaria is exceptionally rare, but for viruses vigorous tests should
be done.
It is mandatory nowadays to test for markers of hepatitis B and C, HIV viruses, and for treponema pallidum.
Immunomodulation:
Now we consider blood transfusion as transplantation.
This transfusion will cause low immunity, and Suppression of the host resistance may have beneficial or
harmful effects on patients.
› If given before surgery for transplantation of organs it minimizes the rejection of the organ transplanted.
› But it has bad effects in tumor surgeries because it lowers the resistance.
› It generally increases the rate of infections during surgery
The End of the Lecture
With Best Regards,
M7MOUD Al-Dari
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