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phlebotOmy (for secondary polycythemia), and fluid resuscitation (for

relative polycyrhemia).

Thrombocytic Disorders

Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) involves the introduction of thromboplastic substances into the circulation that initiate a massive clotting cascade accompanied by fibrin, plasmin, and Pit activation. It is a complex and paradoxic disorder characterized by both hemorrhage and thrombus formation. First, fibrin is deposited in the

microcirculation, leading ro organ ischemia and the destruction of

RBCs as they pass through these deposits. Second, Pits and clotting

facrors are consumed and hemorrhage occurs. Plasmin is activated to

further decrease clotring factOr, and fibrin further inhibits Pit function, which furrher increases bleeding.

O le, either acute or chronic, is always a secondary process

mediated by infla mmatory cytokines.5S The onset of acute DIC

usually occurs in the presence of illness within hours or days of the

initial injury or event. This condition is associated with infection,

trauma, burn injury, shock, tissue acidosis, antigen-antibody complexes, or the entrance of amnioric fluid or placenta intO the maternal circulation. It is highly associated with gram-negative

sepsis.46

Chronic OIC is associated with hemangioma and other cancers

(panicularly pancreatic or prostate cancer), systemic lupus erythematoStlS, or missed abortion.

Signs and symptOms of DIC may include the following:

• Abrupt (in acute DlC) or slow (in chronic DIC) blood loss from

an injury site, nose, gums, or gastrointestinal or urinary tracts

• Thrombosis (for chronic DIC)

• Tachypnea, tachycardia, hypotension, and dysrhyrhmia

• Altered consciousness, anxiery, fear, or restlessness

VASCULAR SYSTEM AND HEMATOLOGY

4 1 1

• Ecchymosis, petechiae, and purpura

• Weakness

• Decreased urine output

• Acute renal failure (for acute DIC)

DIC may be mild and self-limiting or severe and is often associated

with critical illness.56 Management of DIC may include any of the following: treatment of the causative condition; blood and blood product transfusion for active bleeding; fluid, hemodynamic, and shock management; heparin therapy (this is controversial); and recombinant

protein factor therapy (experimental).55

Hemophilia

Hemophilia is a disease characterized by excessive spontaneous hemorrhaging at mucous membranes, into joint spaces (hemarthrosis) and muscles, or intracranially. It is the result of a genetic deficiency of a

clotting factor. There are four basic types57:

1 .

Hemophilia A is characterized by the lack of factor VIll

and is inherited as an X-linked recessive trait.

2.

Hemophilia B (Christmas disease) is characterized by the

lack of factor IX and is inherited as an X -linked recessive trait.

3.

Hemophilia C is characterized by the lack of factor XI and

is inherited as an autosomal recessive trait.

4.

von Willebrand's disease is characterized by the lack of

factor VHf and is inherited as an autosomal dominant trait.

Patients with mild hemophilia experience bleeding only with

trauma or after surgical procedures, whereas patients with severe

hemophilia may bleed with minor trauma or spontaneously.47

Symptoms and physical findings of bleeding episode from hemophilia may include the following:

• Petechiae, purpura, and ecchymosis

• Hematoma

• Disorientation

• Convulsions

4 t 2 AClITE CARE HANDBOOK fOR PHYSICAL THERAPISTS

• Tachycard ia, tachypnea, and hypotension

Management of hemophilia may include any of the following:

methods to stop active bleeding (e.g., direct pressure), supportive

therapy depending on the location of the bleed (e.g., joint debridement), factor replacement therapy, and pain management.50

Clinical Tip

Watch for signs of joint effusion (warmth and edema) in

patients with hemophilia who are prone to hemarthrosis,

especially during weight-bearing activites.

Thalassemia

Thalassemia is an autosomal-recessive disease characterized by

abnormal formation of Hgb chains in RBCs, resulting in RBC membrane damage and abnormal erythropoiesis and hemolysis.

Hgb is composed of two alpha and two beta chains. a-Thalassemia is a defect in alpha-chain synthesis in which one (alpha trait), two (a-thalassemia minor), or three (Hgb H disease) genes are

altered. Each type of a-thalassemia varies in presentation from a

lack of symptoms (alpha trait and minor) to chronic severe

hemolytic anemia (Hgb H) which requires regular blood transfusions.4• p-Thalassemia minor is a defect in beta-chain synthesis in one of two beta chains and is usually asymptomatic. p-Thalassemia

major is a severe reduction or absence in beta-chain production

that results in severe anemia, growth failure, bony deformities,

hepatosplenomegaly, and j aundice with a life expectancy of 20-30

years from complications of heart failure, cirrhosis, and endocrinopathy.47 Management of the thalassemia may include folate supplementation, blood transfusion, iron-chelating agents, and splenectomy.47

Thrombocytopellia

Thrombocytopenia is an acute or chronic d ecrease in the number

of Pits (less than 1 50,000/�1) in the circulation. It can result from

decreased Pit production (caused by infection, drug or immune

responses, or blood vessel damage), increased Pit destruction

(caused by malignancy, antiplatelet antibodies, or the use of

myelosuppressive drugs), or altered Pit distribution (caused by cardiac surgery-induced hypothermia, portal hypertension, or splenomegaly).57

VASCULAR SYSTEM AND HEMATOLOGY

413

Signs and symptoms of thrombocyropenia may include the

foliowingS8:

• Bleeding of nose, gums, or puncture sites or blood in emesis,

urine, or stool

•

Ecchymosis and petechiae

• Tachycardia and tachypnea

•

Signs of increased intracranial pressure if a cranial bleed is

present

• Renal failure

•

Splenomegaly

Management of thrombocytopenia may include any of the following: treatment of the causative factor, immunosuppressive therapy, anticoagulants in plasma transfusion or plasmapheresis, corticosteroids, or splenectomy,57

Heparill-Illduced Thrombocytopenia

Heparin can have a dramatic thrombocyropenic effect, usually 5-10

days after the initiation of heparin therapy. The clinical presentation

of heparin-induced thrombocytopenia (HIT) is distinct and may

include the followingS':

•

Large, bilateral lower-extremity DVT

• Upper-extremity DVT at a venous catheter site

• Skin lesions at the injection site

• Aortic or ileofemoral thrombus with limb ischemia

• Pulmonary embolism

• An acute systemic reaction to heparin

HIT may be type I (the asymptomatic aggregation of Pits) or type

II (an immune response resulting in Pit activation and venous or arterial thrombi)60 HIT is diagnosed by clinical presentation, a Pit count less than 100 x 10'/L and a positive Pit aggregation test. Management

of HIT starts with the immediate discontinuation of heparin and may

include plasmapheresis, immunoglobulin therapy, and anticoagulants

(experimental), in addition to supportive therapies for alteration in

skin integrity and pain,6o