SCHWARTZ,S SCHWARTZ,S PRINCIPLES OF PRINCIPLES OF SURGERY 2005SURGERY 2005PRESENTED PRESENTED BY:KAMRAN ADHAMI BY:KAMRAN ADHAMI M.D.M.D.

A complex process that prevents or A complex process that prevents or terminates blood loss from a disrupted terminates blood loss from a disrupted intravascular spaceintravascular space

4 major physiologic events 4 major physiologic events participate,both in sequence and participate,both in sequence and interdependently,in the hemostatic interdependently,in the hemostatic processprocess

Vascular constriction ,platelet plug Vascular constriction ,platelet plug formation,fibrin formation,and fibrinolysis formation,fibrin formation,and fibrinolysis occur in that general order,but the occur in that general order,but the products of each of these four processes products of each of these four processes are interrelated in such a way that there are interrelated in such a way that there is a continuum and multiple is a continuum and multiple reinforcementsreinforcements

Injury : vasoconstriction is initial vascular response Injury : vasoconstriction is initial vascular response to injury .to injury .

Adherence of endothelial cells to adjacent Adherence of endothelial cells to adjacent endothelial cells may be sufficient to cause endothelial cells may be sufficient to cause cessation of blood loss from the vessel.cessation of blood loss from the vessel.

TXA2,from arachidonic acid from platelet TXA2,from arachidonic acid from platelet membranes during aggregation (vasoconstrictor)membranes during aggregation (vasoconstrictor)

Endothelin , serotonin ,5-Endothelin , serotonin ,5-HT,bradykinin,fibrinopeptidesHT,bradykinin,fibrinopeptides

2 to 4 um in diameter2 to 4 um in diameter 150000-400000/uL150000-400000/uL Up to 30% sequestered in the spleen can Up to 30% sequestered in the spleen can

release in response to catecholaminesrelease in response to catecholamines Average life span 7 to 10 daysAverage life span 7 to 10 days Two pathways:forming a hemostatic plug Two pathways:forming a hemostatic plug

and by contributing to thrombin formationand by contributing to thrombin formation

Injury to the intimal layer in the vascular Injury to the intimal layer in the vascular wall exposes subendothelial collagen to wall exposes subendothelial collagen to which platelets adhere within 15 seconds which platelets adhere within 15 seconds of the traumatic event.of the traumatic event.

vWF in subendothelium (von willebrand)vWF in subendothelium (von willebrand)

Platelets expand and develop pseudopodal Platelets expand and develop pseudopodal processes and also initiate a release reaction processes and also initiate a release reaction that recruits other platelets from the circulating that recruits other platelets from the circulating blood to seal the disrupted vesselblood to seal the disrupted vessel

Primary hemostasis,reversible and is not Primary hemostasis,reversible and is not associated with secretionassociated with secretion

Heparin does not interfere with this reactionHeparin does not interfere with this reaction

In the second wave of platelet In the second wave of platelet aggregation ,a release reaction occurs in aggregation ,a release reaction occurs in which several substances including which several substances including ADP.ca2+,serotonin,TXA2,and alpha ADP.ca2+,serotonin,TXA2,and alpha granule proteins are dischargedgranule proteins are discharged

Compaction of the platelets into an Compaction of the platelets into an amorphous plug,no longer reversibleamorphous plug,no longer reversible

In congenital abnormalities exist,they can In congenital abnormalities exist,they can result in abnormal aggregation ,as a result in abnormal aggregation ,as a result of effects on either the first wave of result of effects on either the first wave of aggregation or the second wave of the aggregation or the second wave of the process(granule release)process(granule release)

Interactions between platelets,vascular Interactions between platelets,vascular wall,and multiple circulating or membrane-wall,and multiple circulating or membrane-bound coagulation factorsbound coagulation factors

Coagulation cascade=2 intersecting Coagulation cascade=2 intersecting pathways:intrinsic and extrinsicpathways:intrinsic and extrinsic

Intrinsic because all are intrinsic to the Intrinsic because all are intrinsic to the circulating plasma and no surface is required to circulating plasma and no surface is required to initiate the processinitiate the process

Extrinsic requires exposure of tissue factor on Extrinsic requires exposure of tissue factor on the surface of the injured vessel wall to initiate the surface of the injured vessel wall to initiate the arm of the cascade beginningthe arm of the cascade beginning

PT:VII-X-V-II-fibrinogenPT:VII-X-V-II-fibrinogen PTT:XII-XI-IX-VIII-X-V-II-fibrinogen-PTT:XII-XI-IX-VIII-X-V-II-fibrinogen-

prekallikrein-high molecular weight prekallikrein-high molecular weight kinninogenkinninogen

Mixing patient plasma 1:1 with normal Mixing patient plasma 1:1 with normal plasma,with and without incubation plasma,with and without incubation for1hour at 37C can distinguish between for1hour at 37C can distinguish between factor deficiency and the presence of an factor deficiency and the presence of an inhibitorinhibitor

Regulation:two related process must exist to Regulation:two related process must exist to balance propagation of the clot before the balance propagation of the clot before the entire vascular bed is thrombosed in response entire vascular bed is thrombosed in response to a local insult.to a local insult.

First,there is a feedback inhibition on the First,there is a feedback inhibition on the coagulation cascade,which deactivates the coagulation cascade,which deactivates the enzyme complexes leading to thrombin enzyme complexes leading to thrombin formationformation

Second,fibrinolysis=breakdown the fibrin clotSecond,fibrinolysis=breakdown the fibrin clot

A third major mechanism=protein C A third major mechanism=protein C systemsystem

thrombin—thrombomodulin---activate thrombin—thrombomodulin---activate protein C to APCprotein C to APC

Its cofactor protein S Its cofactor protein S APC-protein S complex cleaves factors APC-protein S complex cleaves factors

Va and VIIIaVa and VIIIa

FACTOR VIII AND FACTOR IXFACTOR VIII AND FACTOR IX HEMOPHILIA:HEMOPHILIA: Most frequent are hemophilia A and von Most frequent are hemophilia A and von

willebrand disease =factor VIII deficiencywillebrand disease =factor VIII deficiency Hemophilia B or christmas disease Hemophilia B or christmas disease

=factor IX=factor IX Sex-linked recessiveSex-linked recessive

Severe=level less than 1%of normal Severe=level less than 1%of normal Moderate=1% to 5%Moderate=1% to 5% Mild =5%to 30 %Mild =5%to 30 % Severe: severe spontaneous bleeds frequently Severe: severe spontaneous bleeds frequently

into joints,intramuscular into joints,intramuscular hematoma,retroperitoneal hematomas,and hematoma,retroperitoneal hematomas,and gastrointestinal and genitourinary bleedinggastrointestinal and genitourinary bleeding

Intracranial bleeding and retropharyngeal Intracranial bleeding and retropharyngeal bleeding and bleeding from the tongue or bleeding and bleeding from the tongue or lingual frenulum may be life-threateninglingual frenulum may be life-threatening

Mild hemophiliacs don’t bleed Mild hemophiliacs don’t bleed spontaneouslyspontaneously

After major trauma or surgery(platelet After major trauma or surgery(platelet function is normal)function is normal)

May bleed several hours later(tooth May bleed several hours later(tooth extractions or tonsillectomy)extractions or tonsillectomy)

Treatment:factor VIII or factor IX Treatment:factor VIII or factor IX concentrate,respectivelyconcentrate,respectively

Guidelines for replacement:Guidelines for replacement:

CNS and trauma or surgery and CNS and trauma or surgery and retroperitoneal=hemostatic factor level 100% retroperitoneal=hemostatic factor level 100% initially then 50-100% for 10-14 daysinitially then 50-100% for 10-14 days

Retropharyngeal =50-70%Retropharyngeal =50-70% GI system=50-100%GI system=50-100% Hematuria=40%Hematuria=40% Tooth extraction=50%Tooth extraction=50% Mouth=30-40%Mouth=30-40% Intramuscular=40-50%Intramuscular=40-50% Acute hemarthrosis=30-50%Acute hemarthrosis=30-50%

Mild to moderate hemophilia A with minor Mild to moderate hemophilia A with minor bleeds is administraction of DDAVP bleeds is administraction of DDAVP which induces the release of v WF which induces the release of v WF raising the levels of v WF and associated raising the levels of v WF and associated factor VIIIfactor VIII

DDAVP can be given I.V. 0.3ug/kg DDAVP can be given I.V. 0.3ug/kg daily or by nasal spray one puffdaily or by nasal spray one puff

EACA ,amicar,an inhibitor of EACA ,amicar,an inhibitor of fibrinolysis,especially for bleeding fibrinolysis,especially for bleeding because of tooth extraction or other oral because of tooth extraction or other oral bleeding and for urinary tract bleedingbleeding and for urinary tract bleeding

Low factor VIIILow factor VIII Autosomal dominant disorderAutosomal dominant disorder 2function:1-carrier for factor VIII(v WF level are 2function:1-carrier for factor VIII(v WF level are

low,factor VIII levels are variably decrease of low,factor VIII levels are variably decrease of loss of the carrier protein.)loss of the carrier protein.)

2-it is necessary for normal platelet adhesion to 2-it is necessary for normal platelet adhesion to exposed subendothelium and for normal exposed subendothelium and for normal aggregation under high shear condition aggregation under high shear condition

Characteristic of platelet Characteristic of platelet disorders;typically easy bruising and disorders;typically easy bruising and mucosal bleeding.menorrhagia is mucosal bleeding.menorrhagia is common.common.

It has 3 types:It has 3 types: Type I:partial quantitative deficiencyType I:partial quantitative deficiency Type II:qualitative defectType II:qualitative defect Type III:total deficiencyType III:total deficiency

Two options for treatment of itTwo options for treatment of it Use an intermediate purity factor VIII Use an intermediate purity factor VIII

concentrate such as humate-P that concentrate such as humate-P that contains v WF as well as factor VIII.contains v WF as well as factor VIII.

Second option is use of DDAVP, which Second option is use of DDAVP, which raise endogenous v WF levels by release raise endogenous v WF levels by release of the factor from endothelial cellsof the factor from endothelial cells

In general,type I patients respond well to In general,type I patients respond well to DDAVP. Type II patients may DDAVP. Type II patients may respond,depending on the particular respond,depending on the particular defect.type III patients usually do not defect.type III patients usually do not respond.respond.

Hemophilia C Hemophilia C Mild bleeding disorderMild bleeding disorder Autosomal recessive traitAutosomal recessive trait Bleeding may occure after surgery or traumaBleeding may occure after surgery or trauma Treatment is with fresh-frozen plasma FFP.Treatment is with fresh-frozen plasma FFP. Each milliliter of plasma contains 1 unit of factor XI Each milliliter of plasma contains 1 unit of factor XI

activity activity Daily infusion is adequate because the half-life is 48hDaily infusion is adequate because the half-life is 48h DDAVP may also be useful in the prevention of itDDAVP may also be useful in the prevention of it

They are rare.autosomal They are rare.autosomal recessive,significant bleeding in recessive,significant bleeding in homozygotes with less than 1%of normal homozygotes with less than 1%of normal activityactivity

Bleeding is treated with FFP.Bleeding is treated with FFP. FFP contains one unit of activity of X &IIFFP contains one unit of activity of X &II Factor V activity of plasma is somewhat Factor V activity of plasma is somewhat

less less

Rare.Rare. Bleeding is uncommon –level less than Bleeding is uncommon –level less than

3%3% Treatmen with FFP or with recombinant Treatmen with FFP or with recombinant

factor VIIafactor VIIa Half-life is very short(2h)Half-life is very short(2h) Half –life of factor VII in FFP is longer ,Half –life of factor VII in FFP is longer ,

(4h)(4h)

RareRareAutosomal recessiveAutosomal recessiveBleeding is typically delayed because clots form normally Bleeding is typically delayed because clots form normally

but are susceptible to fibrinolysisbut are susceptible to fibrinolysisUmbilical stump bleedingUmbilical stump bleedingIntracranialIntracranialSpontaneous abortion is usualSpontaneous abortion is usualHalf-life is 9to14 daysHalf-life is 9to14 daysReplacement can be accomplished with Replacement can be accomplished with

FFP ,cryoprecipitate ,factor XIII concentrateFFP ,cryoprecipitate ,factor XIII concentrateLevel 1 to 2%Level 1 to 2%

abnormalities of platelet surface abnormalities of platelet surface protein protein

abnormality of platelet granulesabnormality of platelet granules enzyme defectsenzyme defects

Srface protein abnormalities :bernard-soulier syndrom Srface protein abnormalities :bernard-soulier syndrom and thrombasthenia(glanzmann,s disease)and thrombasthenia(glanzmann,s disease)

Absence of functional glycoprotein IIb IIIaAbsence of functional glycoprotein IIb IIIa Receptor for fibrinogen and also a receptor for v WF.Receptor for fibrinogen and also a receptor for v WF. Thrombasthenic patients must be treated with platelet Thrombasthenic patients must be treated with platelet

transfusionstransfusions The bernard-soulier syndrom is caused by a defect in The bernard-soulier syndrom is caused by a defect in

the GP Ib/IX/V receptor for v WF that is necessary for the GP Ib/IX/V receptor for v WF that is necessary for platelet adhesion to the subendotheliumplatelet adhesion to the subendothelium

Transfusion of normal platelets is required for bleeding Transfusion of normal platelets is required for bleeding in these patientsin these patients

The most common intrinsic platelet defect is known as The most common intrinsic platelet defect is known as storage pool disease.storage pool disease.

Dense granule deficiency is the most prevalent of Dense granule deficiency is the most prevalent of these.these.

It may be an isolated defect or occur with partial It may be an isolated defect or occur with partial albinism in the hermansky-pudlak syndrome.albinism in the hermansky-pudlak syndrome.

Bleeding is primary caused by the decreased released Bleeding is primary caused by the decreased released of ADP from these platelets.of ADP from these platelets.

Mild bleeding may decrease bleeding by DDAVPMild bleeding may decrease bleeding by DDAVP Severe bleeding ,platelet transfusion is requiredSevere bleeding ,platelet transfusion is required

PLATELET ABNORMALITIES:PLATELET ABNORMALITIES: Qualitative-quantitative-both typesQualitative-quantitative-both types Quantitative=failure of production,shortened Quantitative=failure of production,shortened

survival,or sequestrationsurvival,or sequestration Failure of production:general marrow Failure of production:general marrow

disorder(leukemia,myelodysplastic disorder(leukemia,myelodysplastic syndrome,severe vitamin B12 or folate syndrome,severe vitamin B12 or folate deficiency,chemotherapeutic deficiency,chemotherapeutic drugs,radiation,acute ethanol intoxication,viral drugs,radiation,acute ethanol intoxication,viral infectioninfection

Platelet transfusion ,with the addition of EACAPlatelet transfusion ,with the addition of EACA

Shortened platelet survival :immune Shortened platelet survival :immune thrombocytopenia,disseminated intravascular thrombocytopenia,disseminated intravascular coagulation, thrombotic thrombocytopenic coagulation, thrombotic thrombocytopenic purpura and hemolytic uremic syndromepurpura and hemolytic uremic syndrome

Immune thrombocytopenia often presents with Immune thrombocytopenia often presents with a very low platelet count,petechiae and a very low platelet count,petechiae and purpura,and epistaxis and gum bleeding.large purpura,and epistaxis and gum bleeding.large platelet are seen on peripheral smear.platelet are seen on peripheral smear.

Treatment is with corticosteroids(1mg/kg per Treatment is with corticosteroids(1mg/kg per day)-or gamma globulin (2g/kg over 2to5 days)day)-or gamma globulin (2g/kg over 2to5 days)

If the platelet count cannot be maintained If the platelet count cannot be maintained medically with these agents,splenectomy medically with these agents,splenectomy is indicated and leads to complete or is indicated and leads to complete or partial remission in 80%of patients.partial remission in 80%of patients.

Platelet transfusion is not needed for Platelet transfusion is not needed for splenectomy in patients with ITP.splenectomy in patients with ITP.

DRUGS THAT SHOULD BE DRUGS THAT SHOULD BE SUSPECTED ARE:SUSPECTED ARE:

heparin,quinidine,quinine,gold heparin,quinidine,quinine,gold salts,sulfonamides,valporic acid,and salts,sulfonamides,valporic acid,and chlorothiazide.chlorothiazide.

HIT:HIT:

Heparin –induced thrombocytopenia is a Heparin –induced thrombocytopenia is a special case of drug-induced immune special case of drug-induced immune thrombocytopenia.thrombocytopenia.

Count fall 5 to 7 days afterCount fall 5 to 7 days after In re-exposure,it may occur within1to2 days.In re-exposure,it may occur within1to2 days. Not severeNot severe Platelet count falls to less than 100000 or it Platelet count falls to less than 100000 or it

drops by 50% from baseline.drops by 50% from baseline.

in Mild to moderate thrombocytopenia ,this is in Mild to moderate thrombocytopenia ,this is characterized by a high incidence of characterized by a high incidence of thrombosis that may be arterial or venous.thrombosis that may be arterial or venous.(HITTS=heparin –induced thrombocytopenia –(HITTS=heparin –induced thrombocytopenia –thrombosis syndrome)thrombosis syndrome)

Heparin should be stopped promptly and an Heparin should be stopped promptly and an alternative anticoagulant should be institutedalternative anticoagulant should be instituted

Lepirudin,argatroban,danaparoidLepirudin,argatroban,danaparoid Warfarin should not be started in them until Warfarin should not be started in them until

count has recovered to greater than 100000count has recovered to greater than 100000

TTP=Thrombotic thrombocytopenic purpuraTTP=Thrombotic thrombocytopenic purpura It is thought that ultralarge v WF molecules It is thought that ultralarge v WF molecules

interact with platelets,leading to activation.interact with platelets,leading to activation. Thrombocytopenia,microangiopathic hemolytic Thrombocytopenia,microangiopathic hemolytic

anemia,renal abnormalities,fever,and anemia,renal abnormalities,fever,and neurologic signs or symptomsneurologic signs or symptoms

Treatment is plasmapheresisTreatment is plasmapheresis platelet Transfusion should not be used in TTP platelet Transfusion should not be used in TTP

unless necessary. unless necessary.

HUS:Hemolytic uremic syndromHUS:Hemolytic uremic syndrom Secondary to infection by escherichia coli Secondary to infection by escherichia coli

0157:H7 or other shiga toxin-producing 0157:H7 or other shiga toxin-producing bacteriabacteria

Some degree of renal failure,neurologic Some degree of renal failure,neurologic symptoms are less frequentsymptoms are less frequent

Thrombocytopenia may occur acutely as Thrombocytopenia may occur acutely as a result of massive blood loss followed by a result of massive blood loss followed by replacement with stored blood.replacement with stored blood.

Exchange of 1 blood volume (11 unit in a Exchange of 1 blood volume (11 unit in a 75-kg man)decreases the platelet count 75-kg man)decreases the platelet count from 250000/Ul to 80000/uL.from 250000/Ul to 80000/uL.

ASPIRIN irreversibly inhibits platelet ASPIRIN irreversibly inhibits platelet function .CLOPIDOGREL and ABCIXIMAB have function .CLOPIDOGREL and ABCIXIMAB have sufficiently long half-lives,therefore platelet transfusion sufficiently long half-lives,therefore platelet transfusion may be required if surgery is indicated within a few may be required if surgery is indicated within a few days of discontinuing therapy.days of discontinuing therapy.

Other Other drugs:indomethacin,ibuprofen,phenothiazines,penicillindrugs:indomethacin,ibuprofen,phenothiazines,penicillins,chelating agents,lidocaine,dextran,betaadrenergic s,chelating agents,lidocaine,dextran,betaadrenergic blockers,nitroglycerin,furosemide,antihistaminesblockers,nitroglycerin,furosemide,antihistamines

In general,50000 platelets/u L is adequate for normal In general,50000 platelets/u L is adequate for normal hemostasis,but if there is associated platelet hemostasis,but if there is associated platelet dysfunction ,there may be a poor correlation between dysfunction ,there may be a poor correlation between the platelet count and the extent of bleeding.the the platelet count and the extent of bleeding.the template bleeding time is the most reliable in vivo test template bleeding time is the most reliable in vivo test of hemostatic function.of hemostatic function.

When thrombocytopenia is present in a patient for When thrombocytopenia is present in a patient for whom an elective operation is being considered,it is whom an elective operation is being considered,it is managed on the basis of how much the platelet count managed on the basis of how much the platelet count is reduced and the cause of the reduction. A count of is reduced and the cause of the reduction. A count of greater than 50000/u L requires no specific therapy.greater than 50000/u L requires no specific therapy.

Sequestration is another important cause of Sequestration is another important cause of thrombocytopenia and usually involves thrombocytopenia and usually involves sequestration of platelets in an enlarged spleen sequestration of platelets in an enlarged spleen from any cause (portal from any cause (portal hypertension,sarcoid,lymphoma,Gaucher,s hypertension,sarcoid,lymphoma,Gaucher,s disease)disease)

Total body platelet mass is essentially normal Total body platelet mass is essentially normal in patients with hypersplenism ,but a much in patients with hypersplenism ,but a much larger fraction of the platelets than normal are larger fraction of the platelets than normal are in the enlarged spleen.in the enlarged spleen.

Platelet transfusion doesnot increase the Platelet transfusion doesnot increase the count as much as it would in a normal count as much as it would in a normal person because the transfused platelets person because the transfused platelets will end up in the spleen.will end up in the spleen.

Splenectomy is not indicated to correct Splenectomy is not indicated to correct the thrombocytopenia of hypersplenism the thrombocytopenia of hypersplenism caused by portal hypertensioncaused by portal hypertension

One unit of platelet concentrate contains One unit of platelet concentrate contains 5.5*10^10 platelets and would be expected to 5.5*10^10 platelets and would be expected to increase the circulating platelet count by about increase the circulating platelet count by about 10000/u L in the average 70-kg person.hence 10000/u L in the average 70-kg person.hence a transfusion of 4 to 8 pool platelet a transfusion of 4 to 8 pool platelet concentrates should raise the count by 40000 concentrates should raise the count by 40000 to 80000/u L and should provide adequate to 80000/u L and should provide adequate hemostasis,as documented by bleeding time hemostasis,as documented by bleeding time and control of the hemorrhagic manifestations.and control of the hemorrhagic manifestations.

The polycythemic patient,particularly with The polycythemic patient,particularly with marked thrombocytosis,is a major surgical risk.marked thrombocytosis,is a major surgical risk.

If possible,the operation should be deferred If possible,the operation should be deferred until medical management has effected normal until medical management has effected normal blood volume,hematocrit level,and platelet blood volume,hematocrit level,and platelet count.count.

Spontaneous thrombosis is a complication of Spontaneous thrombosis is a complication of polycythemia vera and can be explained in part polycythemia vera and can be explained in part by increased blood viscosity,increased platelet by increased blood viscosity,increased platelet count,and an increased tendency toward count,and an increased tendency toward stasis.stasis.

TREATMENT:TREATMENT: Hydroxyurea or anagrelideHydroxyurea or anagrelide Elective surgical procedures should be delayed Elective surgical procedures should be delayed

weeks to months after institution of treatment.weeks to months after institution of treatment. HCT less than 48%, platelet count under HCT less than 48%, platelet count under

400000/u L 400000/u L In emergency procedures,phlebotomy and In emergency procedures,phlebotomy and

replacement of the blood removed with replacement of the blood removed with lactated Ringer,s solution.lactated Ringer,s solution.

All of the coagulation factors are synthesized All of the coagulation factors are synthesized by hepatocytes,although factor VIII level by hepatocytes,although factor VIII level behave differently from those of other factors behave differently from those of other factors with hepatic insufficiency.with hepatic insufficiency.

Levels of the vitamin K –dependent factors and Levels of the vitamin K –dependent factors and factor V decrease progressivelyfactor V decrease progressively

Fibrinogen and factor VIII levels tend to be Fibrinogen and factor VIII levels tend to be elevated with mild liver disease.elevated with mild liver disease.

Fibrinogen levels decrease with progression Fibrinogen levels decrease with progression from COOK,s class A to B to C cirrhosis.factor from COOK,s class A to B to C cirrhosis.factor VIII is low only with very severe liver disease.VIII is low only with very severe liver disease.

Thrombocytopenia is seen in patients with Thrombocytopenia is seen in patients with cirrhosis who have hypersplenism.cirrhosis who have hypersplenism.

Treatment of bleeding in patients with Treatment of bleeding in patients with coagulopathy caused by liver disease usually coagulopathy caused by liver disease usually done with FFPdone with FFP

If the fibrinogen is less than 100mg/dL, If the fibrinogen is less than 100mg/dL, administration of cryoprecipitate(8to 10 administration of cryoprecipitate(8to 10 bags)may be helpful.bags)may be helpful.

Platelet sequestration Platelet sequestration Total body platelet mass is essentially normal Total body platelet mass is essentially normal

in patients with hypersplenism,but a much in patients with hypersplenism,but a much larger fraction of the platelets than normal are larger fraction of the platelets than normal are in the enlarged spleen.in the enlarged spleen.

Platelet transfusion does not increase the Platelet transfusion does not increase the platelet count as much as it would in a normal platelet count as much as it would in a normal person because the transfused platelets will person because the transfused platelets will end up in the spleenend up in the spleen

Spontaneous bleeding may be a complication Spontaneous bleeding may be a complication of anticoagulant therapy with either of anticoagulant therapy with either heparin,warfarin,or one of the newer heparin,warfarin,or one of the newer anticoagulants,low molecular weight heparinsanticoagulants,low molecular weight heparins

It is reduced with a continuous infusion It is reduced with a continuous infusion technique,regulating the a PTT between 1.5 technique,regulating the a PTT between 1.5 and 2.5 times the upper limit of normal.and 2.5 times the upper limit of normal.

Therapeutic anticoagulation is more reliably Therapeutic anticoagulation is more reliably achieved with low molecular weight achieved with low molecular weight heparin,and laboratory testing is not routinely heparin,and laboratory testing is not routinely used to monitor dosing of these agents.used to monitor dosing of these agents.

Effect of the warfarin is reduced in receiving Effect of the warfarin is reduced in receiving barbituratesbarbiturates

Increase warfarin requirements have also been Increase warfarin requirements have also been documented in patients taking contraceptives,other documented in patients taking contraceptives,other estrogen-containing compounds,corticosteroids,and estrogen-containing compounds,corticosteroids,and adrenocorticotropic hormone(ACTH)adrenocorticotropic hormone(ACTH)

Medications known to increase the effect of oral Medications known to increase the effect of oral anticoagulants include phenylbutazone,the cholesterol-anticoagulants include phenylbutazone,the cholesterol-lowering agent clofibrate,anabolic steroids,l-lowering agent clofibrate,anabolic steroids,l-thyroxine,glucagons,amidarone,quinidine,and variety of thyroxine,glucagons,amidarone,quinidine,and variety of antibiotics(cephalosporins)antibiotics(cephalosporins)

Present with epistaxis,G I Present with epistaxis,G I hemorrhage,hematuria,ecchymoses,petehemorrhage,hematuria,ecchymoses,petechiae,hematomachiae,hematoma

Bleeding secondary to anticoagulation Bleeding secondary to anticoagulation therapy is not an uncommon cause of therapy is not an uncommon cause of rectus sheath hematoma,simulating rectus sheath hematoma,simulating appendicitis,and intramural intestinal or appendicitis,and intramural intestinal or retroperitoneal hematoma.retroperitoneal hematoma.

Certain surgical procedures should not be Certain surgical procedures should not be performed in the face of anticoagulation .(CNS performed in the face of anticoagulation .(CNS –eye)–eye)

Because of the added problem of local Because of the added problem of local fibrinolysis,prostatic surgical treatment should fibrinolysis,prostatic surgical treatment should not be carried out in a patient on not be carried out in a patient on anticoagulantsanticoagulants

Blind needle introduction should be avoidedBlind needle introduction should be avoided

Discontinuation of heparin may be Discontinuation of heparin may be sufficient if the operation can be delayed sufficient if the operation can be delayed for several hours,for more rapid for several hours,for more rapid reversal,1 mg of protamine sulfate for reversal,1 mg of protamine sulfate for every 100 units of heparin most recently every 100 units of heparin most recently administered is immediately effective.administered is immediately effective.

Parenteral administration of vitamin K also is Parenteral administration of vitamin K also is indicated in elective surgical treatment of indicated in elective surgical treatment of patients with biliary obstruction or patients with biliary obstruction or malabsorption who may be vitamin K-deficient.malabsorption who may be vitamin K-deficient.

The drug should result in a normal PT or The drug should result in a normal PT or INR.By contrast ,if low levels of factors INR.By contrast ,if low levels of factors II,VII,IX,X are a result of hepatocellular II,VII,IX,X are a result of hepatocellular dysfunction,vitamin K administration is dysfunction,vitamin K administration is ineffectiveineffective

Vitamin K therapy should not be prolonged Vitamin K therapy should not be prolonged over 1 week if no response is noted.over 1 week if no response is noted.

Significant surgical bleeding is usually caused Significant surgical bleeding is usually caused by ineffective local hemostasis.by ineffective local hemostasis.

The goal of local hemostasis is to prevent or The goal of local hemostasis is to prevent or interrupt the flow of blood from a disrupted interrupt the flow of blood from a disrupted vessel that has been incised or transected.vessel that has been incised or transected.

Hemostasis may be accomplished by Hemostasis may be accomplished by interrupting the flow of blood to the involved interrupting the flow of blood to the involved area or by direct closure of the blood vessel area or by direct closure of the blood vessel wall defect.wall defect.

The techniques are classified as The techniques are classified as MECHANICAL,THERMAL,CHEMICALMECHANICAL,THERMAL,CHEMICAL

The oldest mechanical method of effecting The oldest mechanical method of effecting closure of a bleeding point,or of preventing closure of a bleeding point,or of preventing blood from entering the area of disruption,is blood from entering the area of disruption,is digital pressure.digital pressure.

TourniquetTourniquet Pringle maneuver ,which occludes the hepatic Pringle maneuver ,which occludes the hepatic

artery and portal vein in the hepatoduodenal artery and portal vein in the hepatoduodenal ligament as a method of controlling bleeding ligament as a method of controlling bleeding from a transected cystic artery or the raw from a transected cystic artery or the raw surface of the liver.surface of the liver.

The most obvious disadvantage of digital pressure is The most obvious disadvantage of digital pressure is that it cannot be used permanently.that it cannot be used permanently.

A ligature or a hemoclip replaces the hemostat as a A ligature or a hemoclip replaces the hemostat as a permanent method of effecting hemostasis of a single permanent method of effecting hemostasis of a single disrupted vessel.disrupted vessel.

When a small vessel was transected ,a simple ligature When a small vessel was transected ,a simple ligature is sufficient .is sufficient .

For large arteries with pulsation and longitudinal For large arteries with pulsation and longitudinal motion,a transfixion suture to prevent slipping is motion,a transfixion suture to prevent slipping is indicated.indicated.

When the bleeding is from a lateral defect in a large When the bleeding is from a lateral defect in a large vessel,sutures are required .vessel,sutures are required .

The adventitia and media constitute the The adventitia and media constitute the major holding forces in a vessel wall,and major holding forces in a vessel wall,and multiple fine sutures or small hemoclips multiple fine sutures or small hemoclips are preferable.are preferable.

Nonabsorbable sutures,such as Nonabsorbable sutures,such as silk,polyethylene ,and wire,evoke less silk,polyethylene ,and wire,evoke less tissue reaction than absorbable material tissue reaction than absorbable material such as catgut,polyglycolic,and vicryl.such as catgut,polyglycolic,and vicryl.

Diffuse bleeding from multiple small Diffuse bleeding from multiple small vessels can be controlled by pressure vessels can be controlled by pressure applied directly over the bleeding applied directly over the bleeding area,and this is now deemed preferable area,and this is now deemed preferable to the prolonged use of a proximally to the prolonged use of a proximally placed tourniquet because the latter is placed tourniquet because the latter is associated with a greater danger of associated with a greater danger of tissue necrosis.tissue necrosis.

Direct pressure applied by means of pack Direct pressure applied by means of pack affords the best method of controlling diffuse affords the best method of controlling diffuse bleeding from large areas.bleeding from large areas.

Unless the heat is so great as to denature Unless the heat is so great as to denature protein,it can actually increase protein,it can actually increase bleeding,whereas cold packs promote bleeding,whereas cold packs promote hemostasis by inducing vascular spasm and hemostasis by inducing vascular spasm and increasing endothelial adhesiveness.increasing endothelial adhesiveness.

Bleeding from cut bone can be controlled by Bleeding from cut bone can be controlled by packing beeswax on the raw surface to effect packing beeswax on the raw surface to effect pressure.pressure.

Heat achieves hemostasis by Heat achieves hemostasis by denaturation of protein that result in denaturation of protein that result in coagulation of large areas of tissue.coagulation of large areas of tissue.

When electrocautery is employed ,the When electrocautery is employed ,the amplitude setting should be high enough amplitude setting should be high enough to produce prompt coagulation,but not so to produce prompt coagulation,but not so high as to set up an arc between the high as to set up an arc between the tissue and the cautery tip.tissue and the cautery tip.

Advantage of the cautery is that it saves Advantage of the cautery is that it saves time;the disadvantage is that more tissue is time;the disadvantage is that more tissue is necrosed than with precise ligature.necrosed than with precise ligature.

Local cooling has been applied to control Local cooling has been applied to control bleeding from the eroded mucosa of the bleeding from the eroded mucosa of the esophagus and stomach.esophagus and stomach.

Direct cooling with iced saline is effective and Direct cooling with iced saline is effective and acts by increasing the local intravascular acts by increasing the local intravascular hematocrit and by causing vasoconstriction of hematocrit and by causing vasoconstriction of the arterioles.the arterioles.

Epinephrine ,injected locally or applied Epinephrine ,injected locally or applied topically ,induces vasoconstriction and topically ,induces vasoconstriction and can reduce bleeding.can reduce bleeding.

The drug is generally used for an oozing The drug is generally used for an oozing site such as the tonsillar bed or for a site such as the tonsillar bed or for a bleeding duodenal ulcer that is bleeding duodenal ulcer that is concurrently cauterized.concurrently cauterized.

Materials are gelatin(gelfoam),oxidized Materials are gelatin(gelfoam),oxidized cellulose (oxycel),oxidized regenerated cellulose (oxycel),oxidized regenerated cellulose (surgicel),and micronized cellulose (surgicel),and micronized collagen (avitene)collagen (avitene)