Page 2010 - Williams Hematology ( PDFDrive )

1985

CHAPTER 116 Eliciting and interpreting all of the relevant information requires a
systematic and methodical approach. The following points are worth
CLASSIFICATION, CLINICAL considering:
1. Patients vary in their responses to hemorrhagic symptoms. Some
MANIFESTATIONS, AND patients ignore significant symptoms, whereas other patients are
highly sensitive to even minor symptoms. When asked in stan-
EVALUATION OF DISORDERS dardized questionnaires, many normal, healthy people indicate
they have excessive bleeding or bruising. Therefore, some experts
1,2
believe the question “Do you bruise easily?” is virtually worthless.
OF HEMOSTASIS Women are more likely to respond that they have excessive bleed-
ing or bruising than are men.
2. Patients with severe hemorrhagic disorders invariably have very
abnormal bleeding histories, for example, severe hemophilia A or
Marcel Levi, Uri Seligsohn, and Kenneth Kaushansky hemophilia B, type 3 (homozygous) von Willebrand disease, and
Glanzmann thrombasthenia. Importantly, these patients may expe-
rience spontaneous bleeding episodes.
SUMMARY 3. The diagnostic value of any specific symptom varies in the differ-
ent disorders. Therefore, recognizing typical patterns of bleeding
is important (Table 116–2). Unprovoked hemarthroses and muscle
Evaluation of a hemostatic disorder is commonly initiated when (1) a patient hemorrhages suggest one of the hemophilias, whereas mucocu-
or referring physician suspects a bleeding tendency, (2) a bleeding tendency taneous bleeding (epistaxis, gingival bleeding, menorrhagia) are
is discovered in one or more family members, (3) an abnormal coagulation more characteristic of patients with qualitative platelet disorders,
assay result is obtained from an individual as part of a routine examination, thrombocytopenia, or von Willebrand disease.
(4) an abnormal assay result is obtained from a patient during preparation 4. Assessing the extent of hemorrhage against the background of any
for surgery, or (5) a patient has unexplained diffuse bleeding during or after trauma or provocation that may have elicited the hemorrhage is
surgery or following trauma. Evaluation of a possible hemostatic disorder in important. If a patient has never had a significant hemostatic chal-
each of these scenarios is a stepwise process that requires knowledge of the lenge, such as tooth extraction, surgery, trauma, or childbirth,
various classes of hemostatic disorders commonly found under the particular the lack of a significant bleeding history is much less valuable in
circumstances. The patient’s history, the results of physical examination, and excluding a mild hemorrhagic disorder. For example, a significant
an initial set of hemostatic tests usually enable a tentative diagnosis. However, percentage of patients with mild von Willebrand disease or mild
forms of hemophilia may have negative bleeding histories, even
1
more specific tests are commonly necessary to make a definitive diagnosis. though they may be at considerable risk for excessive bleeding after
This chapter reviews the necessary steps. surgery or other interventions. Thus, these diagnoses must be con-
sidered even in elderly patients if their first severe hemostatic chal-
lenge occurs at that age.
CLASSIFICATION OF HEMOSTATIC 5. Obtaining objective confirmation of the subjective information
conveyed in the bleeding history is valuable. Objective data include
DISORDERS (1) previous hospital or physician visits for bleeding symptoms,
(2) results of previous laboratory evaluations, (3) previous transfu-
Hemostatic disorders can conveniently be classified as either hereditary sions of blood products for bleeding episodes, and (4) a history of
or acquired (Table 116–1). Alternatively, hemostatic disorders can be anemia and/or previous treatment with iron.
classified according to the mechanism of the defect. Of the acquired 6. Although self-administered questionnaires may provide useful
disorders, the thrombocytopenias are the most frequently encountered background information, they cannot substitute for a dialogue
entities. Thrombocytopenias can result from reduced production of between the physician and the patient. Thus, history taking in gen-
platelets, excessive destruction caused by antibodies or other consump- eral, but especially in the often subtle histories related to hemostatic
tive processes, or pooling of platelets in the spleen, as in hypersplenism disorders, is an intellectually active process involving data collec-
(Chap. 119); however, if hypersplenism is the sole cause of a hemostatic tion, hypothesis development, new question formulation, addi-
disorder, it is rarely severe enough to cause pathologic bleeding. tional data gathering, and new hypothesis development. However,
this iterative procedure has its limitations even when it is carefully
BLEEDING HISTORY pursued. 3,4
7. A medication history is a crucial component of the bleeding history,
The bleeding history is a crucial element in the evaluation of a patient with particular attention to nonprescription drugs, such as aspi-
with a hemorrhagic disorder. The bleeding history helps define the rin and nonsteroidal antiinflammatory agents, which may affect
subsequent diagnostic approach and the likelihood of future bleeding. bleeding symptoms. A medication history is especially impor-
tant in patients with thrombocytopenia, because drug-induced
thrombocytopenia is common (Chap. 120 and see Table 116–1).
Medication also may affect hemostasis through deleterious effects
Acronyms and Abbreviations: aPTT, activated partial thromboplastin time; DIC, on the liver or kidney functions. The increased use of herbal and
disseminated intravascular coagulation; ELISA, enzyme-linked immunosorbent alternative medicines poses particular problems, because patients
assay; PT, prothrombin time; RCF, ristocetin cofactor. may not readily share information about what they are taking, and
the dose they are taking of any particular active ingredient may

Kaushansky_chapter 116_p1985-1992.indd 1985 9/18/15 10:12 AM