Risk Factors For Thrombocytopenia Research Articles

Assessment of thrombocytopenia in critically ill patients

BackgroundThrombocytopenia is commonly observed among critically ill patients.AimThe aim of this study was to evaluate the incidence, risk factors, and the outcome of thrombocytopenia in patients admitted to the respiratory intensive care unit (RICU).Materials and methodsData were collected from 50 adult patients admitted to the RICU in a 6-month period. The baseline platelet count was measured and was repeated every other day during the RICU stay period. Thrombocytopenia was defined as platelet count of less than 150´109/l.ResultsThe incidence of thrombocytopenia was 20% (10 patients). The overall mortality was 16%, of which 50% of the patients were having thrombocytopenia. The thrombocytopenic group had a higher mortality (40 vs. 10%, P < 0.05), a lower admission platelet count (215.3 ± 85.6 vs. 252.8 ± 73.2, P < 0.05), a lower nadir platelet count (111.1 ± 22.6 vs. 213.9 ± 53.2, P < 0.001), an increased transfusion requirement (30 vs. 2.5%, P < 0.05), and increased septic shock (40 vs. 2.5%, P < 0.05) compared with the nonthrombocytopenic group. Comorbidities, indications for RICU admission, the length of RICU stay, mechanical ventilation, days on mechanical ventilation, admission severity scores, bleeding, ICU-related complications, and medications administrated during the RICU stay did not differ significantly. A prolonged RICU stay of more than 15 days carried a 4.7 times higher incidence of development of thrombocytopenia. Thrombocytopenia differed significantly between survivors and nonsurvivors (P < 0.05), with a significant effect on mortality (P = 0.034).ConclusionThrombocytopenia is common among critically ill patients and affects the mortality significantly. Prolonged ICU stay and septic shock are among the risk factors for thrombocytopenia. Egypt J Broncho 8:143–148

Factors associated with thrombocytopenia in severe leptospirosis (Weil's disease)

OBJECTIVE:This study was conducted to investigate factors associated with thrombocytopenia in a large cohort of patients with leptospirosis in an endemic area.METHODS:This retrospective study included 374 consecutive patients with leptospirosis who were admitted to tertiary hospitals in Fortaleza, Brazil. All patients had a diagnosis of severe leptospirosis (Weil's disease). Acute kidney injury was defined according to the RIFLE criteria. Thrombocytopenia was defined as a platelet count <100,000/mm3.RESULTS:A total of 374 patients were included, with a mean age of 36.1±15.5 years, and 83.4% were male. Thrombocytopenia was present at the time of hospital admission in 200 cases (53.5%), and it developed during the hospital stay in 150 cases (40.3%). The patients with thrombocytopenia had higher frequencies of dehydration (53% vs. 35.3%, p = 0.001), epistaxis (5.7% vs. 0.8%, p = 0.033), hematemesis (13% vs. 4.6%, p = 0.006), myalgia (91.5% vs. 84.5%, p = 0.038), hematuria (54.8% vs. 37.6%, p = 0.011), metabolic acidosis (18% vs. 9.2%, p = 0.016) and hypoalbuminemia (17.8% vs. 7.5%, p = 0.005). The independent risk factors associated with thrombocytopenia during the hospital stay were lengthy disease (OR: 1.2, p = 0.001) and acute kidney injury (OR: 6.6, p = 0.004). Mortality was not associated with thrombocytopenia at admission (12.5% vs. 12.6%, p = 1.000) or during the hospital stay (12.6% vs. 11.3%, p = 0.748).CONCLUSIONS:Thrombocytopenia is a frequent complication in leptospirosis, and this condition was present in more than half of patients at the time of hospital admission. Lengthy disease and acute kidney injury are risk factors for thrombocytopenia. There was no significant association between thrombocytopenia and mortality.

A Case of Thrombocytopenia Associated With Valproic Acid Treatment

To the Editor: Thrombocytopenia is a condition in which the blood has a lower than the normal platelet count. Thrombocytopenia is derived from the old term thrombocytes, ie, cells responsible for blood clotting or thrombus.1 Bone marrow produces platelets along with other kinds of blood cells. Normal platelet count is between 150,000 and 450,000/μL of blood. Even though a platelet count of less than 150,000/μL of blood is lower than normal, risk of mild bleeding occurs only when the platelet count falls below 50,000/μL of blood. The risk of serious bleeding occurs when the level is below 20,000/μL of blood.2 Thrombocytopenia can occur when the bone marrow fails to produce the normal levels of platelets in conditions such as certain cancers that affect stem cells, aplastic anemia, exposure to toxic chemicals, viruses, and excessive consumption of alcohol. Thrombocytopenia can also occur when the body destroys its own platelets after the bone marrow makes enough platelets, eg, in conditions such as thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, and drug-induced thrombocytopenia. Drug-induced thrombocytopenia can be caused by certain drugs such as vancomycin, phenytoin, sulfa-containing antibiotics, quinine, and rifampin.2 These drugs cause serious reaction with platelets in sensitive people by producing drug-dependent antibodies that destroy the platelets and thus lower the platelet count. Platelet count can be normalized by stopping the drug, and the identification of the responsible drug is important to prevent reexposure.1 Thrombocytopenia can cause external bleeding in the form of petechiae, purpura on skin, bleeding from nose and mouth, or internal bleeding in any part of the body leading to a medical emergency. Thrombocytopenia can be easily identified by a routine blood test such as a complete blood cell (CBC) count, which can be followed up with other tests as needed.2 Mild-to-moderate thrombocytopenia needs no treatment most of the time. Severe thrombocytopenia can be treated by steroids, blood or platelet transfusions, and splenectomy if other treatments fail.2 Case report. Mr A, a 23-year-old Hispanic man, presented with a diagnosis of bipolar disorder (DSM-IV criteria). His weight was 178 lb. He was started on treatment with valproic acid 500 mg twice daily. Initial laboratory values were within normal limits, including a baseline platelet level of 348,000/μL. After 1 week of treatment, his platelets were checked again; his platelet count had decreased to 38,000/μL. The patient has no other risk factors for thrombocytopenia or any previous history. Valproic acid was immediately stopped, and another CBC count was obtained 1 week later; his platelet level had increased to 208,000/μL. Platelet level increased again to 300,000/μL 3 weeks after cessation of valproic acid treatment. This case, like some other cases,3,4 shows that valproic acid treatment is associated with thrombocytopenia. The case demonstrates thrombocytopenia induced by treatment with valproic acid in a relatively young patient after only a week of treatment. The risk of thrombocytopenia caused by valproic acid is 5%, and the risk increases with the age of the patient and with the level of valproic acid in the blood.4–6 In this case, the patient was young and had received a standard dose of valproic acid for a week when his platelet count dropped to 38,000/μL, which alerted us to check the CBC count regularly in all patients treated with valproic acid. The risks caused by thrombocytopenia can be easily prevented by promptly stopping the drug and monitoring the patient every week until the platelet count normalizes.7

Thrombocytopenia in the critically ill: prevalence, incidence, risk factors, and clinical outcomes

The aim of this cohort study was to describe the prevalence, incidence, and risk factors for thrombocytopenia in the intensive care unit (ICU) and to evaluate the impact of thrombocytopenia on mortality with further comparisons amongst major diagnostic categories. Patients admitted to the ICU from 1997-2011 for cardiac, medical, surgical, and trauma conditions were included. The presence of a platelet count < 100 × 10(9)·L(-1) on admission day or its appearance during ICU stay were considered as prevalent and incident thrombocytopenia, respectively. Risk factors for thrombocytopenia and the influence of thrombocytopenia on mortality were also analyzed. This study included 20,696 patients. Prevalent and incident thrombocytopenia occurred in 13.3% and 7.8% of patients, respectively, with associated mortality rates of 14.3% and 24.7%, respectively, compared with 10.2% in the group with normal platelet count (P < 0.001). After adjustments, thrombocytopenia remained associated with an increased risk of mortality (odds ratio 1.25; 95% confidence interval 1.20 to 1.31; P < 0.001). The greatest impact of thrombocytopenia on mortality was observed in the cancer, respiratory, digestive, genitourinary, and infectious diagnostic categories. Independent risk factors included age, female sex, admission platelet counts and hemoglobin, mechanical ventilation, days of hospitalization prior to ICU admission, liver cirrhosis, hypersplenism, coronary bypass grafting, intra-aortic balloon pump placement, acute hepatitis, septic shock, and pulmonary embolism or deep vein thrombosis. Thrombocytopenia in the ICU is associated with an independent risk of mortality that varies greatly depending on diagnostic admission category.

The Prevalence and Risk Factors of Thrombocytopenia After Living-Related Renal Transplantation in Chinese Adult Recipients

ObjectiveTo evaluate the prevalence of and risk factors for thrombocytopenia during the first year after living-related renal transplantation of Chinese patients. MethodsThis retrospective study was performed in 274 adult kidney transplant recipients between January 2009 and December 2010. We followed each for ≥1 year. Posttransplant thrombocytopenia (PTT) was defined as a platelet (PLT) count ≤100 × 109/mL at any time after transplantation; a severe case was considered to be <50 × 109/mL. Possible risk factors for PTT were analyzed using univariate methods with key factors determined by multivariate analysis. ResultsThe prevalence of PTT was high (33.9%) during the first year, but severe PTT occured only among 4.0% of patients. The lowest PLT often happened in the first 3 months after the operation. Key risk factors associated with PTT were induction therapy (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.3–4.1; P = .005) and infection (OR, 2.2; 95% CI, 1.3–3.8; P = .004) upon multivariate analysis. Severe PTT correlated with induction therapy (OR, 9.9; 95% CI, 1.7–56.2; P = .010) and acute rejection episodes (OR, 7.8; 95% CI, 1.4–42.4; P = .018). ConclusionsPTT was quite prevalent in the first year after renal transplantation. Most recipients showed the lowest PLT count in the first 3 months. However, severe cases, which correlated with induction therapy and acute rejection episodes, were rare.

Thrombocytopenia at birth in neonates with red cell alloimmune haemolytic disease

To evaluate the incidence and severity of and risk factors for thrombocytopenia at birth in neonates with red cell alloimmunization. All neonates with haemolytic disease of the foetus/newborn (HDFN) due to red cell alloimmunization admitted to our centre between January 2000 and September 2010 were included in this retrospective study. We measured platelet counts at birth and determined the incidence of thrombocytopenia (platelet count<150×10(9)/l) and severe thrombocytopenia (platelet count<50×10(9)/l). Risk factors for thrombocytopenia at birth were evaluated. Thrombocytopenia was present in 26% (94/362) of included neonates with HDFN at birth. Severe thrombocytopenia was found in 6% (20/362) of neonates. Three risk factors were found to be independently associated with thrombocytopenia at birth: treatment with intrauterine red cell transfusion (IUT) (OR 3·32, 95% CI 1·67-6·60, P=0·001), small for gestational age (SGA) below the 10th percentile (OR 3·32, 95% CI 1·25-8·80, P=0·016) and lower gestational age at birth (OR 1·22/week, 95% CI 1·02-1·44, P=0·025). Thrombocytopenia at birth occurs in 26% of neonates with HDFN due to red cell alloimmunization and is independently associated with IUT treatment, SGA and lower gestational age at birth.

Splenomegaly and thrombocytopenia in patients with liver cirrhosis

Splenomegaly is a frequent finding in patients with liver cirrhosis and portal hypertension and may cause hypersplenism. The occurrence of thrombocytopenia in those patients can be considered as an event with multiple etiologies. Two mechanisms may act alone or synergistically with splenic sequestration. One is central which involves either myelosuppression because of hepatitis viruses or the toxic effects of alcohol abuse on the bone marrow. The second one involves the presence of antibodies against platelets. It also depends upon the stage and etiology of liver disease. The aim of the study was to investigate a correlation between the platelet count and spleen size and the risk factors for thrombocytopenia in patients with liver cirrhosis. We studied 40 patients with decompensated liver cirrhosis who were hospitalized in the Department of Gastroenterohepatology. The liver function was graded according to Child Pugh score. Spleen size was defined ultrasonografically on the basis of craniocaudal length. Suspicion of portal hypertension was present when longitudinal spleen length was more than 11 cm. Thrombocytopenia was determined by platelet count under 150,000/mL. We did not find any significant correlation between hepatic dysfunction and spleen size (p = 0.9), and between hepatic dysfunction and thrombocytopenia (p = 0.17). Our study did not find any significant correlation between spleen size and peripheral platelet count (p = 0.5), but we found a significant correlation between thrombocytopenia and etiology of cirrhosis - decreased platelet count was more common among patients with cirrhosis of alcoholic etiology than in other etiologies of cirrhosis (p = 0.001). According to our study, liver cirrhosis, portal hypertension and thrombocytopenia could be present even in the absence of enlarged spleen suggesting the involvement of other mechanisms of decreasing platelet account.

Incidence and Risk Factors of Thrombocytopenia in Patients Receiving Intermittent Antiretroviral Therapy: A Substudy of the ANRS 106-Window Trial

Incidence and risk factors for thrombocytopenia in patients discontinuing highly active antiretroviral therapy (HAART) have not been fully investigated. Well-suppressed patients on HAART were randomized to continuous (CT) or intermittent therapy (IT) for 96 weeks. Incidence of thrombocytopenia (<150 x 10(3) platelets/mm(3)) was assessed and multivariate analysis performed to identify baseline predictors. Correlations were assessed between platelet, CD4, CD8 T-cell counts, and viral load after treatment interruption. Three hundred ninety-one patients were included, with a median baseline platelet count of 243,000/mm(3). The incidence of thrombocytopenia at week 96 was significantly higher in the IT versus the CT arm (25.4% versus 9.8%, respectively, P < 0.001) and median time to thrombocytopenia was 9 weeks. In multivariate analysis, the IT strategy: odds ratio (OR) = 4.1 (2.1-7.9; P < 0.0001), a history of thrombocytopenia: OR = 11.9 (2.4-57.9; P = 0.002), and a low baseline platelet count: OR = 3.4 (2.3-5.1; P < 0.0001) were associated with an increased risk of thrombocytopenia. Also, after treatment interruption, changes from baseline in platelet counts were correlated with changes in CD4 T-cell counts and plasma HIV RNA levels (P < 0.001 for both). Intermittent therapy is associated with a high incidence of thrombocytopenia, especially among patients with low platelet counts and a history of thrombocytopenia.

Risk Factors for Thrombocytopenia in Patients Treated With Prolonged Heparin Therapy—Reply

Risk Factors for Thrombocytopenia in Patients Treated With Prolonged Heparin Therapy—Reply

Risk Factors for Thrombocytopenia in Patients Treated With Prolonged Heparin Therapy

Risk Factors for Thrombocytopenia in Patients Treated With Prolonged Heparin Therapy

Incidence and significant predicting factors for chemotherapy-induced severe thrombocytopenia in lymphoma patients

20519 Background: Severe thrombocytopenia (TCP) is a complication of chemotherapy (CT), resulting in frequent transfusions and treatment delays. The incidence and risk factors for TCP in lymphoma patients (pts) with current CT regimens are not well defined. Methods: Medical records of 1046 newly referred lymphoma pts to MD Anderson Cancer Center in 2003 were retrospectively reviewed over two years follow-up period. The incidence of severe TCP was determined, and logistic regression models were employed to identify the significant baseline clinical and laboratory features correlated with severe TCP. Results: 404 pts, who received ≥ 1 cycle of treatment and had adequate laboratory records, were included in the analysis (total CT cycles 2061). Grade (GR) 4 TCP (PLT nadir < 25×103/μL) was observed in 42% (170/404) of pts, in the median cycle 2 (range 1-11) and median PLT nadir of 12×103/μL (1- 24×103/μL). Bleeding occurred in 48% (81/170) of pts with GR 4 TCP compared to 8% (19/234) of pts with higher PLT counts (p=0.0001), although most bleedings (95%) were minor. Seventy-nine percent (134/170) of pts with GR 4 TCP received PLT transfusions, compared to only 2% (4/234) of pts with higher PLTs (p<0.0001). 137 out of 170 (81%) GR 4 TCP pts and 245 out of 398 (62%) GR 4 TCP episodes occurred in the 1st regimen. Therefore the logistic regression models analyzed the data set of 1st regimen. In the multivariate model, following variables were most important predictive factors for GR 4 TCP. Conclusions: The incidence of severe TCP in lymphoma pts is high. Predictive risk factors can be very useful to develop prophylactic strategy with PLT growth factors in high risk pts to prevent TCP related complications. Variable Odds Ratio (95% CI) P value Myelosuppressive Risk of Regimen ( high vs low) 38.60 (18.70–79.66) <0.0001 Extra Nodal Involvement (yes vs no) 2.57 (1.29–5.09) 0.007 Type of Previous Therapy* (CT+RT vs no Rx) 3.53 (1.33–9.33) 0.011 PLT Count 0.995 (0.993–0.998) 0.001 Serum Beta2MicroG 1.153 (1.03–1.29) 0.014 * RT: radiotherapy; no statistical significance between RT or CT±surgery vs no Rx. No significant financial relationships to disclose.

Incidence and Risk Factors for Severe Thrombocytopenia in Lymphoma Patients Receiving Chemotherapy.

Background: Severe thrombocytopenia (TCP) can be a serious complication of chemotherapy (CT) in lymphoma patients (pts), however the exact incidence with the current regimens and risk factors for TCP are not well known.Methods: A retrospective cohort study was conducted to determine the incidence of TCP, and logistic regression analysis were performed to identify the clinical and laboratory features correlated with severe TCP in lymphoma. Medical records of 538 consecutive pts out of the 1050 lymphoma pts, who were newly referred to MDACC in 2003, were reviewed.Results: 202 pts who received > 1 cycle of treatment were included in the analysis. The total number of CT cycles (with PLT counts) for the 202 pts was 985 (median 6, range, 1–20). Grade (gr) 4 TCP (PLT nadir < 25x103/μL) was observed in 39% (79/202) of pts and 20% (196/985) of cycles. The median cycle in which gr 4 TCP occurred was 2 (range, 1 to 11), and median PLT nadir count for gr 4 TCP was 12x103/μL (3 to 24x103/μL). The regimens most commonly associated with gr 4 TCP were Hyper-CVAD/ Ara-c/Mtx (31/35=89%), ESHAP (6/7=86%), ASHAP (3/4=75%), and ICE (5/7=71%) + rituxan, and the most common histological subtypes were MCL (15/19=79%), Burkitts lymphoma (7/9=78%), T cell lymphoma (10/17=58%), and LCL (31/64=48%). Thirty two of 79 (41%) gr 4 TCP pts had bleeding as compared to 8 of 123 (7%) pts with higher PLT counts (p=0.0001). Overall, the incidence of bleeding was 20% (40/202) by pts and 6% (60/985) by cycles; however, the most incidents [95% (57/60)] were minor. 80% (63/79) of Grade 4 TCP pts received PLT transfusions, as compared to only 2% (2/123) of the rest (p<0.0001). Using multivariate logistic regression, histological gr, (highly aggressive or aggressive vs indolent: OR=10.402, 95% CI, 3.991 to 27.107, p<0.0001), baseline PLT count (≤150 vs >150x103/μL: OR=4.610, 95% CI, 1.366 to 15.560, p=0.0138), prior therapy (yes vs. no: OR=2.575, 95% CI, 1.337 to 4.961, p=0.0047), Beta2 Microglobulin (B2M) (≥2 vs <2mg/L: OR=2.846, 95% CI, 1.401 to 5.783, p=0.0038), age (>60 vs. ≤60 yrs: OR=0.479, 95% CI, 0.241 to 0.952, p=0.0356) were the most important risk factors for grade 3 or 4 TCP.Conclusions: The incidence of severe TCP in this population is high. Baseline pt characteristics including histological gr, PLT counts, prior therapy, age and serum B2M were found to be significant risk factors predictive for chemotherapy-induced TCP (CIT). These findings could be useful to identify high risk pts for consideration of treatment approaches for prevention and treatment of CIT.

Thrombocytopenia in a Surgical ICU

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. Prospective study. An 8-bed surgical ICU in an 885-bed teaching hospital. 147 consecutive patients admitted to the surgical ICU during a 6-month period. 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. 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 patients. 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.

Incidence and risk factors of thrombocytopenia in critically ill trauma patients.

To determine the incidence of thrombocytopenia (< 100 platelets x 10(3)/mm3) and potential risk factors, including medications, associated with the development of thrombocytopenia in critically ill trauma patients. Prospective, observational study. A 20-bed trauma intensive care unit (ICU) at a university hospital. Sixty-three critically ill trauma patients without baseline thrombocytopenia admitted to the trauma ICU for at least 48 hours. Patients were followed for up to 14 days. Platelet counts were determined daily. The following data were collected and analyzed as potential risk factors for the development of thrombocytopenia: medications, age, sex, race, trauma score, mode and type of injury, alcohol history, units of packed red blood cells (PRBC) and platelets transfused, surgical procedures, duration of ICU stay, and the development of systemic inflammatory response syndrome or disseminated intravascular coagulation. Thrombocytopenia occurred in 26 (41%) of the patients. Among risk factors studied, nonhead injury, age, trauma score, duration of ICU stay, and the number of PRBC transfusions were significantly associated with the development of thrombocytopenia (p < 0.05). However, nonhead injury, age, and trauma score were useful variables in predicting the development of thrombocytopenia by using multivariate analysis. Medications were not associated with the development of thrombocytopenia. The type of injury sustained, the quantity of platelet-deficient, transfusions, and age are the greatest risk factors associated with the development of thrombocytopenia in critically ill trauma patients. Drug-induced thrombocytopenia appears to play a minor role in the development of thrombocytopenia; therefore, medications should not be automatically discontinued or substituted when thrombocytopenia occurs.

Prevalence of thrombocytopenia in HIV-infected and non-HIV infected drug users and homosexual men.

We studied the prevalence and risk factors for thrombocytopenia among 299 drug users and 461 homosexual men. The prevalence of thrombocytopenia was 3.3% in HIV-negative homosexual men, 8.7% in HIV-negative drug users, 16.4% in HIV-positive homosexual men, and 36.9% in HIV-positive drug users. With multivariate logistic regression HIV-seropositivity (odds ratio 3.3), a history of injecting drugs (OR 3.9), an increased number of lymphocytes (OR 0.44), an increased number of neutrophils (OR 0.53) and a larger mean platelet volume (OR 2.8) were independently and significantly associated with thrombocytopenia. The results obtained with linear regression analysis were consistent with the results of the logistic regression. The higher prevalence of thrombocytopenia among drug users was related to a history of intravenous drug use but not to recent injecting. The mechanisms causing thrombocytopenia among HIV-positives and HIV-negatives seem to be related, but HIV-infection seems to enhance thrombocytopenia in an independent way.