Study objectives: To assess the
incidence of thrombocytopenia in surgical ICU patients, the factors
associated with thrombocytopenia, the outcome of thrombocytopenic
patients, and the possible mechanisms involved.
Design: Prospective study.
8-bed surgical ICU in an 885-bed teaching hospital.
Patients: 147 consecutive patients admitted to the surgical
ICU during a 6-month period.
Main outcome measures:
Incidence of thrombocytopenia (defined by a platelet count< 100,000/mm3), risk factors for thrombocytopenia, or
death in thrombocytopenic patients identified by a stepwise logistic
regression analysis, as well as the mechanisms involved.
Results: Thrombocytopenia occurred in 52 patients (35%)
with a mortality rate of 38%, compared with a 20%mortality rate in
nonthrombocytopenic patients (p = 0.02). Sepsis, episodes of bleeding
or transfusions, and an acute physiology and chronic health evaluation
(APACHE) II score of > 15 were the independent risk factors
identified for thrombocytopenia. The correction of thrombocytopenia was
a protective factor reducing the risk of mortality in thrombocytopenic
patients. Disseminated intravascular coagulation was found in 40% of
thrombocytopenic patients, elevated platelet-associated IgG in 33%,
and hemophagocytic histiocytes in 67%. Combinations of two of these
mechanisms were demonstrated in one quarter of thrombocytopenic
Conclusions: Sepsis was the major
independent risk factor identified. Thrombocytopenic patients had a
higher ICU mortality due to the severity of overall clinical status.
Bone marrow examination could be diagnostic when no obvious causes are
demonstrated. Thrombocytopenia probably reflects the severity and
course of an underlying pathologic condition, as its correction appears
to be a good prognostic factor.
Abbreviations: APACHE = acute
physiology and chronic health evaluation; CI = confidence interval;
DIC = disseminated intravascular coagulation;
Fio2 = fraction of inspired oxygen;
OR = odds ratio; PAIgG = platelet-associated IgG;
THR+ = thrombocytopenic; THR− = nonthrombocytopenic