Thrombocytosis in intensive care

Association between minimal decrease in platelet counts and outcomes in septic patients: a retrospective observational study

OBJECTIVES

Although platelets have been linked to inflammatory development in sepsis, knowledge on their role as an indicator in sepsis treatment is scarce. Here, we investigated the association between time-dependent changes in platelet counts with mortality rates to reveal the role of platelets in sepsis therapy.

DESIGN

A retrospective cohort study.

SETTING

We screened the Medical Information Mart for Intensive Care (MIMIC-IV), a public database comprising data from critical care subjects at the Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts, USA.

PARTICIPANTS

A total of 7981 patients, who were admitted to the BIDMC between 2008 and 2019, were analysed based on Sepsis-3 criteria from MIMIC-IV.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary and secondary outcomes included 30-day mortality after admission and length of intensive care unit (ICU) stay and hospitalisation, respectively.

RESULTS

Patients with ≤10% reduction in proportion of platelet counts were associated with significantly lower 30-day mortality (14.1% vs 23.5%, p<0.001, Kaplan-Meier analysis, p<0.0001). Multivariable analysis revealed that decreased platelet-count percentage ≤10% on day 4 after ICU admission was associated with lower probability of 30-day non-survival (OR=0.73, 95% CI 0.64 to 0.82, p＜0.001). Patients in the ≤10% group had significantly shorter ICU stays than those in the >10% group (6.8 vs 7.5, p＜0.001). Restricted cubic spline curves revealed that mortality rates decreased with increase in proportion of platelet counts.

CONCLUSIONS

A ≤10% decrease in platelet-count percentage among sepsis patients after treatments is independently associated with decreased 30-day mortality, suggesting that changes in proportion of platelet counts after treatments could be an indicator for assessing the therapeutic effects of sepsis.

Reactive Thrombocytosis in Non-aneurysmal Subarachnoid Hemorrhage

BACKGROUND

 The role of reactive thrombocytosis in non-aneurysmal subarachnoid hemorrhage (NA-SAH) is largely unexplored to date. Therefore, the impact of a quantitative thrombocyte dynamic in patients with NA-SAH and its clinical relevance were analyzed in the present study.

METHODS

 In this retrospective analysis, 113 patients with nontraumatic and NA-SAH treated between 2003 and 2015 at our institution were included. World Federation of Neurosurgical Societies admission status, cerebral vasospasm, delayed infarction, hydrocephalus, need for ventriculoperitoneal (VP) shunt, and Fisher grade were analyzed for their association with reactive thrombocytosis.

RESULTS

 Reactive thrombocytosis was not associated with hydrocephalus (p ≥ 0.05), need for VP shunt implantation (p ≥ 0.05), cerebral vasospasm (p ≥ 0.05), or delayed cerebral ischemia (p ≥ 0.05).

CONCLUSION

 Our study is the first to investigate the role of thrombocyte dynamics, reactive thrombocytosis, and the clinical course of NA-SAH patients. Our analysis showed no significant impact of thrombocyte count on NA-SAH sequelae.

Etiology and clinical relevance of elevated platelet count in ICU patients : A retrospective analysis

BACKGROUND

Thrombocytosis is a common phenomenon in critically ill patients. Although thrombocytosis is an independent risk factor for complications, it does not seem to influence mortality in intensive care (ICU) patients.

OBJECTIVES

Our investigation aimed to evaluate the etiological and clinical relevance of a platelet count greater than 450 × 10⁹/l in ICU patients.

MATERIALS AND METHODS

Patients admitted for a minimum of 4 days to an interdisciplinary ICU during a 45-month period were enrolled in this retrospective observational study. Thrombocytopenic patients (platelet count <150 × 10⁹/l in at least one measurement) were excluded. The study patients were divided into two groups: thrombocytosis group (thrombocytes >450 × 10⁹/l in at least one measurement) and control group (thrombocytes = 150 - 450 × 10⁹/l during ICU stay). Univariate and multiple regression analysis were used to determine the influence of severe co-morbidities on the development of thrombocytosis and the association of elevated platelet count with thrombotic embolism, length of stay (LOS) in ICU, and mortality.

RESULTS

A total of 307 patients were analyzed, of whom thrombocytosis was observed in 119 cases. Independent risk factors for the development of thrombocytosis included SIRS, mechanical ventilation, and acute bleeding. Increasing age reduced the risk of thrombocytosis. Thromboembolism occurred in 16 patients (13.4%) with an elevated platelet count and only in nine patients (4.7%) with physiological platelet values (OR: 3.1; 95% CI: 1.3-7.2; p = 0.009). Mean duration of LOS was significantly longer in patients with thrombocytosis (25.2 vs.11.7 days, p < 0.0001). Elevated platelet count showed a negative correlation with ICU mortality (OR: 0.32; 95%-CI: 0.12-0.83; p = 0.019).

CONCLUSION

In our retrospective analysis the occurrence of thrombocytosis in a cohort of interdisciplinary ICU patients was associated with a higher rate of complications and longer LOS in the ICU. Despite these findings, thrombocytosis seems to reduce mortality in critical ill patients.

Deep vein thrombosis of upper extremities due to reactive thrombocytosis in septic patients

Deep venous thrombosis (DVT) is not an uncommon condition in the intensive care unit (ICU), and having high morbidity and mortality. Upper limb DVT also is increasingly being recognized as a clinical entity. The presence of the indwelling catheter in neck veins is a risk for developing venous thrombus, which may be further aggravated by presence of thrombocytosis. In ICU patients with sepsis, reactive thrombocytosis has been found during the recovery phase. Here, we are presenting two cases, having thrombocytosis and central venous catheter who developed upper limb DVT.

Low Molecular Weight Heparin Induced Skin Necrosis without Platelet Fall Revealing Immunoallergic Heparin Induced Thrombocytopenia

Low molecular weight heparins (LMWH) are commonly used in the ICU setting for thromboprophylaxis as well as curative decoagulation as required during renal replacement therapy (RRT). A rare adverse event revealing immunoallergic LMWH induced thrombopenia (HIT) is skin necrosis at injection sites. We report the case of a patient presenting with skin necrosis witnessing an HIT after RRT, without thrombocytopenia. The mechanism remains unclear. Anti-PF4/heparin antibodies, functional tests (HIPA and/or SRA), and skin biopsy are of great help to evaluate differential diagnosis with a low pretest probability 4T's score.

Extreme Thrombocytosis in Trauma Patients: Are Antiplatelet Agents the Answer?

The purpose of this study was to review the incidence of extreme thrombocytosis (ExT) (platelet count 1,000,000/μL or greater) in trauma patients and to examine the role of antiplatelet agents in its treatment. The Los Angeles County Medical Center trauma registry was used to obtain injury demographics, medications, and daily platelet counts for injured patients 16 years of age or older admitted between July 2005 and February 2008. Of 6,985 total trauma patients admitted during the study period, 95 developed ExT (1.4%). Average age was 29 years (range, 16-63 years), 89 per cent were male, 44 per cent had penetrating trauma, and mean Injury Severity Score was 24 (range, 1-57). Of the 95 patients with ExT, 41 were treated with aspirin (43%) and 54 were not (57%). The two groups did not differ with regard to basic demographics, injury patterns, vitals on admission, or splenectomy rate (34 vs 20%, P = 0.13). After adjusting for maximum platelet counts and duration of ExT, there was no difference between the treated and untreated groups in terms of mortality, complications, and intensive care unit or hospital lengths of stay. The incidence of ExT is approximately 1.4 per cent in trauma patients. Antiplatelet therapy does not affect ExT patient outcome. Further prospective studies are warranted.

What is the significance of thrombocytosis in patients with trauma?

BACKGROUND

The incidence and risk factors for the development of thrombocytosis after trauma have not been well established. Although it has been suggested that the occurrence of this sequela may be associated with adverse events, there are also limited data regarding outcomes of patients developing posttraumatic thrombocytosis. The objective of this study was to determine the incidence of, risk factors for, and sequela of posttraumatic thrombocytosis.

METHODS

A retrospective review of all trauma intensive care unit (ICU) admissions between July 1998 and December 2005 identified patients with early (< or = 7 days), late, and no thrombocytosis. Bivariate analysis was used to compare the clinical and demographic characteristics with outcomes between the three patient groups.

RESULTS

A total of 3,484 patients were admitted to the ICU during the 7-year study period. After exclusions, the study population consisted of 3,286 patients. The overall incidence of thrombocytosis was 18.7%; early thrombocytosis was found in 72 patients, and late thrombocytosis was identified in 542 patients. All complications examined were significantly higher in patients with thrombocytosis. Overall, the venous thromboembolic rate was 2.4%; for patients with thrombocytosis it was 4.6% compared with 1.9% in patients without thrombocytosis. Overall mortality was 15.4%, but was significantly lower in patients with thrombocytosis (3.8% vs. 18.1%, p < 0.0001). Independent risk factors for the development of thrombocytosis included obesity, laparotomy, blunt injury, Injury Severity Score > 16, mechanical ventilation, Chest Abbreviated Injury Score > 3, and tachycardia.

CONCLUSION

Thrombocytosis is a common finding among patients with trauma admitted to the ICU. The occurrence of both early and late thrombocytosis is associated with significantly higher rates of complications, particularly venous thromboembolism. However, patients developing posttraumatic thrombocytosis may have a significantly lower mortality compared with those without this sequela of injury.

Megakaryocytes and platelet homeostasis in diffuse alveolar damage

Platelet homeostasis reflects a balance between the production of platelets via cytoplasmic fragmentation of megakaryocytes in the pulmonary microvasculature and their catabolism. Increased numbers of megakaryocytes are entrapped in the injured lung, potentially affecting circulating platelet counts. We enumerated pulmonary megakaryocytes and blood platelets in patients with diffuse alveolar damage (DAD) in order to determine their association with clinical outcome. Lung biopsies were examined from 21 patients with histologically documented DAD in its proliferative phase and secondary to a variety of causes. Blood platelet counts were determined within 24 h prior to lung biopsy, and CD61+ pulmonary megakaryocytes were localized in in situ immunohistochemical stains. The overall mortality in this series was 67%. Patients with DAD attributable to drug toxicity (DAD-D) had higher mortality (80%) and greater number of intrapulmonary CD61+ megakaryocytes than those with DAD due to other causes (23+/-7, 10+/-2, p<0.05). Patients with blood platelet counts =350 th/cm(3) showed increased survival (p<0.05). The findings support the hypothesis that abnormal platelet homeostasis is associated with increased mortality in acute lung injury and indicate that thrombocytosis in ARDS is associated with improved survival. The mechanisms of altered platelet homeostasis in DAD merit further investigation.

Thrombocytosis after trauma: incidence, aetiology, and clinical significance

BACKGROUND

Our aim was to assess the occurrence, aetiology, and clinical significance of a platelet count greater than 600 x 10(3)/mm(3) in trauma patients.

METHODS

All trauma patients admitted to the intensive care unit (ICU) during a 13-month period were prospectively studied. Platelet counts were performed daily. We recorded the patient's age, sex, nature of trauma, severity of illness scores, episodes of infections in the ICU, acute lung injury, bleeding, and thromboembolic events. Patients with thrombocytosis were also followed during their hospital stay and 1 month after hospital discharge.

RESULTS

A total of 176 patients were included. Thrombocytosis developed in 36 patients (20.4%) at a mean (sd) time of 14.0 (4.0) days and the platelet count normalized 35.0 (13.0) days after admission to the ICU. All patients with thrombocytosis had one or more possible predisposing conditions before the occurrence of thrombocytosis: nosocomial infection occurred in 30 patients (83%), acute lung injury in 17 (47%), bleeding in 27 (75%), and administration of cathecholamines in 24 (67%). Three venous thromboembolic complications occurred in the ICU (1.7%) and one during follow-up. Only one patient presented thrombocytosis at the time of diagnosis. Despite the fact that patients with thrombocytosis had a greater severity of illness, the ICU mortality was comparable among patients with and without thrombocytosis (8 vs 14%, P=0.34).

CONCLUSIONS

Reactive thrombocytosis is a common finding after severe trauma and was found to be associated with a better survival than predicted by severity of illness score. Unless additional risk factors are present, reactive thrombocytosis is not associated with an increased risk of thromboembolic events.