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quent transfusions.
Disseminated Intravascular Coagu-
lation
I.Clinical manifestations
A.Disseminated intravascular coagulation (DIC) is
manifest by generalized ecchymosis and petechiae,
bleeding from peripheral IV sites, central catheters,
surgical wounds, and oozing from gums.
B.Gastrointestinal and urinary tract bleeding are
frequently encountered. Grayish discoloration or
cyanosis of the distal fingers, toes, or ears may occur
because of intravascular thrombosis. Large, sharply
demarcated, ecchymotic areas may be seen as a result
of thrombosis.
II.Diagnosis
A.Fibrin degradation products are the most sensitive
screening test for DIC; however, no single laboratory
parameter is diagnostic of DIC.
B.Peripheral smear: Evidence of microangiopathic
hemolysis, with schistocytes and thrombocytopenia, is
often present. A persistently normal platelet count
nearly excludes the diagnosis of acute DIC.
C.Coagulation studies: INR, PTT, and thrombin time
are generally prolonged. Fibrinogen levels are usually
depleted (
(>10 mg/dL) and D-dimer is elevated (>0.5 mg/dL).
III.Management of disseminated intravascular coagu-
lation
A.The primary underlying precipitating condition (eg,
sepsis) should be treated. Severe DIC with
hypocoagulability may be treated with replacement of
clotting factors. Hypercoagulability is managed with
heparin.
B.Severe hemorrhage and shock is managed with
fluids and red blood cell transfusions.
C.If the patient is at high risk of bleeding or actively
bleeding with DIC: Replace fibrinogen with 10 units of
cryoprecipitate. Replace clotting factors with 2-4 units
of fresh frozen plasma. Replace platelets with platelet
pheresis.
D.If factor replacement therapy is transfused,
fibrinogen and platelet levels should be obtained 30-60
minutes post-transfusion and every 4-6 hours thereafter
to determine the efficacy of therapy. Each unit of
platelets should increase the platelet count by 5000
10,000/mcL. Each unit of cryoprecipitate should in
crease the fibrinogen level by 5-10 mg/dL.
E.Heparin
1.Indications for heparin include evidence of fibrin
deposition (ie, dermal necrosis, acral ischemia,
venous thromboembolism). Heparin is used when
the coagulopathy is believed to be secondary to a
retained, dead fetus, amniotic fluid embolus, giant
hemangioma, aortic aneurysm, solid tumors, or
promyelocytic leukemia. Heparin is also used when
clotting factors cannot be corrected with replace
ment therapy alone.
2.Heparin therapy is initiated at a relatively low dose
(5-10 U/kg/hr) by continuous IV infusion without a
bolus. Coagulation parameters must then be fol
lowed to guide therapy. The heparin dose may be
increased by 2.5 U/kg/hr until the desired effect is
achieved.
Thrombolytic-associated Bleeding
I.Clinical presentation: Post-fibrinolysis hemorrhage may
present as a sudden neurologic deficit (intracranial
bleeding), massive GI bleeding, progressive back pain
accompanied by hypotension (retroperitoneal bleeding),
or a gradual decline in hemoglobin without overt evidence
of bleeding.
II.Laboratory evaluation
A.Low fibrinogen (
degradation products confirm the presence of a lytic
state. Elevated thrombin time and PTT may suggest a
persistent lytic state; however, both are prolonged in
the presence of heparin. Prolonged reptilase time
identifies the persistent lytic state in the presence of
heparin.
B.Depleted fibrinogen in the fibrinolytic state will be
reflected by an elevated PTT, thrombin time, or
reptilase time. The post-transfusion fibrinogen level is
a useful indicator of response to replacement therapy.
C.The bleeding time may be a helpful guide to platelet
replacement therapy if the patient has persistent
bleeding despite factor replacement with
cryoprecipitate and fresh frozen plasma.
III.Management
A.Discontinue thrombolytics, aspirin, and heparin
immediately, and consider protamine reversal of
heparin and cryoprecipitate to replenish fibrinogen.
B.Place two large-bore IV catheters for volume replace
ment. If possible, apply local pressure to bleeding sites.
Blood specimens should be sent for INR/PTT,
fibrinogen, and thrombin time. Reptilase time should be
checked if the patient is also receiving heparin. Pa
tient's blood should be typed and crossed because
urgent transfusion may be needed.
C.Transfusion
1.Cryoprecipitate (10 units over 10 minutes) should
be transfused to correct the lytic state. Transfusions
may be repeated until the fibrinogen level is above
100 mg/dL or hemostasis is achieved.
Cryoprecipitate is rich in fibrinogen and factor VIII.
2.Fresh frozen plasma transfusion is also important
for replacement of factor VIII and V. If bleeding
persists after cryoprecipitate and FFP replacement,
check a bleeding time and consider platelet transfu
sion if bleeding time is greater than 9 minutes. If
bleeding time is less than 9 minutes, then
antifibrinolytic drugs may be warranted.
D.Antifibrinolytic agents
1.Aminocaproic acid (EACA) inhibits the conversion
of plasminogen to plasmin. It is used when replace
ment of blood products are not sufficient to attain
hemostasis.
2.Loading dose: 5 g or 0.1 g/kg IV infused in 250 cc
NS over 30-60 min, followed by continuous infusion
at 0.5-2.0 g/h until bleeding is controlled. Use with
caution in upper urinary tract bleeding because of
the potential for obstruction.
References: See page 157.
Infectious Diseases
Bacterial Meningitis
The age group at greatest risk for acute bacterial meningi
tis (ABM) includes children between 1 and 24 months of
age. Adults older than 60 years old account for 50% of all
deaths related to meningitis.
I.Clinical presentation
A.Eighty-five percent of patients with bacterial meningi
tis present with fever, headache, meningismus or
nuchal rigidity, and altered mental status. Other com
mon signs and symptoms include photophobia, vomit
ing, back pain, myalgias, diaphoresis, and malaise.
Generalized seizures can occur in up to 40% of patients
with ABM.
B.Kernig's sign (resistance to extension of the leg while
the hip is flexed) and Brudzinski's sign (involuntary
flexion of the hip and knee when the patient's neck is
abruptly flexed while laying supine) are observed in up
to 50% of patients.
C.About 50% of patients with N. meningitidis may
present with an erythematous macular rash, which
progresses to petechiae and purpura.
II.Patient evaluation
A.Computerized tomography (CT). Patients who
require CT prior to LP include those with focal neuro
logic findings, papilledema, focal seizures, or abnormal
ities on exam that suggest increased intracranial
pressure. If bacterial meningitis is a strong considera
tion, and the decision is made to perform a CT prior to
LP, two sets of blood cultures should be obtained and
antibiotics should be administered before sending the
patient for neuroimaging. Urine cultures may be helpful
in the very young and very old.
B.Blood cultures followed by antibiotic administration
within 30 minutes of presentation is mandatory in all
patients suspected of having bacterial meningitis.
C.Interpretation of lumbar puncture. Examination of
the CSF is mandatory for evaluation of meningitis.
D.CSF, Gram s stain, and culture are positive in 70
85% of patients with ABM.
Cerebrospinal Fluid Analysis in Meningitis
Par Nor- Bac- Vi Fun- T Par
a- mal terial ral gal B a-
me- men-
ter inge
al
Fo-
cus
or
Ab-
sces
s
WB
C
cou 0 >1000 10 100- 10 10-
nt 0- 500 0- 1000
(WB 10 50
C/ 00 0
:L)
% 0 90
PMN 0 0
% >50 >5 >80
lymp 0
h
Glu- 45-
cose 65 5- 45 0- 65
(mg/ 65 45
dL)
CSF: 0.6
bloo 6 .4
d
glu-
cose
ratio
Pro- 20- >150 5 100- 10 >50
tein 45 0- 500 0-
(mg/ 10 50
dL) 0 0
Par Nor- Bac- Vi Fun- T Par
a- mal terial ral gal B a-
me- men-
ter inge
al
Fo-
cus
or
Ab-
sces
s
Ope 3596 >180 N >180 >1 N/A
ning 5 mm L mm 80
pres H20 or H20 m
sure + m
(cm H2
H20) 0
E.If the CSF parameters are nondiagnostic, or the
patient has been treated with prior oral antibiotics,
and, therefore, the Gram's stain and/or culture are
likely to be negative, then latex agglutination (LA) may
be helpful. The test has a variable sensitivity rate,
ranging between 50-100%, and high specificity. Latex [ Pobierz całość w formacie PDF ] - zanotowane.pl
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