04 Etiology and clinical relevance of elevated platelet count in ICU patients

Originalien

Med Klin Intensivmed Notfmed 2018 · 113:101–107 M. Banach1 · C. Lautenschläger2 · P. Kellner1,3 · J. Soukup1,4
DOI 10.1007/s00063-017-0276-y
Received: 19 January 2017 1 Department of Anaesthesiology and Intensive Care Medicine, Martin-Luther-University, Halle-
Accepted: 21 February 2017 Wittenberg, Halle (Saale), Germany
Published online: 31 March 2017 2 Institute of Medical Epidemiology, Biostatistics and Informatics, Martin-Luther-University Halle-
© Springer Medizin Verlag GmbH 2017 Wittenberg, Halle (Saale), Germany

Editorial board 3 Klinik für Anästhesiologie und Intensivmedizin, Universitätsklinikum Schleswig-Holstein, Campus
M. Buerke, Siegen Lübeck, Lübeck, Germany

4 Department of Anaesthesiology, Intensive Care and Palliative Medicine, Carl-Thiem-Hospital, Cottbus,
Germany

Etiology and clinical relevance of
elevated platelet count in ICU
patients

A retrospective analysis

Background though simultaneously related to a longer charge, the first day on which platelets
ICU stay [12, 26, 33]. exceeded the physiological range, and
Since platelets play a central role in the the day on which they normalized as
interaction between coagulation and in- The purpose of this study was to as- well as the maximum and the mini-
flammation [8, 24, 38], a variation in sess the etiology and to verify the previ- mum platelet count were recorded for
platelet count may considerably influ- ous findings concerning the relevance of each patient from daily laboratory mea-
ence the course of severe disease and a reactive elevated platelet count in a het- surements. Thrombocytopenic patients
the outcome in critically ill patients. Af- erogeneous population of ICU patients. (platelets count less than 150 × 109/l in at
ter admission to the intensive care unit least one measurement) were excluded
(ICU), patients often shows a biphasic Patients and methods from the study, except for patients de-
course of platelet counts, with an initial veloping thrombocytopenia in addition
decrease below baseline values followed Patients admitted to the interdisciplinary to thrombocytosis while in the ICU.
by an increase to the normal range or ICU of the Department of Anaesthesi-
higher after 1 week [2, 21]. According ology and Intensive Care Medicine of In our study thrombocytosis was de-
to the current literature, about 25% to the Martin Luther University, Halle- fined as a platelet count over 450 × 109/l
even nearly 33% of ICU patients have at Wittenberg (Halle, Germany), for 4 days occurring at least once during the ICU
least one episode of platelet counts being or more during a 45-month observation stay, as this value is one of the diagnostic
greater than 450 × 109/l [12, 16]. period were included in this study. Be- criteria of essential thrombocythemia
cause of the retrospective observational [32]. Based on the maximal platelet
However, to date, the etiology and character of our analysis and consistent count during the ICU stay, the study pa-
clinical relevance of an elevated platelet with the regulations of data protection, tients were retrospectively divided into
count in the complex course of critical an approval of the local ethics com- two groups:
diseases is not fully clarified. Although mittee was not necessary at this time. A. Platelet count exceeded 450 × 109/l
an increased platelet count is considered All data were obtained retrospectively
a risk factor for thrombotic embolism in from the Patient Data Management Sys- in at least one count (thrombocytosis
medical and surgical patients [16, 26, 28, tem (PDMS Version 7.0, ICM Dräger group)
29, 31], it does not seem to worsen the Medical, Lübeck, Germany) database B. Platelet count always remaining
outcome in critically ill patients. Previous and were anonymized for subsequent between 150 × 109/l and 450 × 109/l
studies concerning ICU patients showed analysis. In the case of a readmission to (control group)
that thrombocytosis was associated with the ICU, each admission was considered
a lower ICU and hospital mortality, al- separately. The duration of stay was In the thrombocytosis group, addition-
rounded to the nearest whole day and ally, the days of the first occurrence
P. Kellner and J. Soukup contributed equally to the ICU history of each patient was fol- of thrombocytosis and of the maximal
this study. lowed up until ICU discharge or death. platelet count in the ICU as well as the
The platelet counts at admission and dis- day of its normalization were recorded.

Medizinische Klinik - Intensivmedizin und Notfallmedizin 2 · 2018 101

Originalien

Total number of admitted patients in (MOF), disseminated intravascular co-
the indicated period (n=752) agulation (DIC), acute bleeding as well
as the necessity and duration of me-
Excluded (n=445) chanical ventilation were also recorded,
patients with platelet representing conditions that were pre-
count < 150 x 109/l in at viously identified as predisposing to re-
least one measurement active thrombocytosis [7, 11, 33]. SIRS
was defined according to the ACCP/
Included in the further analysis SCCM Consensus Conference Criteria
(n=307) [5]. Based on the American Thoracic
Society and Infectious Disease Society
Thrombocytosis group Control group of America Guidelines, pneumonia was
considered if patients developed a lung
Patients with platelet count Patients with platelet count infiltrate with leukocytosis or leukopenia
> 450 x 109/l in at least one 150–450 x 109/l (n=289) or fever [4]. The bacterial culture of the
sputum or of tracheal or bronchial secre-
measurement (n=119) tions was not considered in this study.
MOF was defined as the deterioration
Fig. 1 8 Flow diagram of inclusion and exclusion criteria for our retrospective analysis according to or loss of the function of a minimum
the CONSORT [19] Statement. n number of patients of two organs at the same time. Only
ARF demanding renal replacement ther-
1000 Sex apy was recorded. DIC was identified
800 by a decrease in two or more of the
Male following markers: prothrombin time
Female (Quick’s method in percentage), fibrino-
Male gen level, antithrombin III, and platelet
Female count within 24 h without preceding
or accompanying bleeding. Since the
Maximal platelet count (x109/l) 600 D-dimers were not monitored in each
patient, they were not included in the
400 DIC criteria in this study. Only major
Male (R=0.21; p=0.006) bleeding episodes requiring operative in-
Female (R=0.28; p=0.001) tervention with local tamponade and/or
blood transfusions within 24 h were
200 recorded. In addition, we registered all
cases of cardiac arrest with cardiopul-
0 monary resuscitation prior to admission
or during the ICU stay. Furthermore,
0 20 40 60 80 100 we registered all cases of symptomatic
Age (years) deep vein thrombosis (diagnosed by
duplex sonography) or/and pulmonary
Fig. 2 8 Correlation of maximal platelet count and patients’ age. Correlation of maximum platelet embolism (confirmed by computer to-
count and age was calculated for all patients and is given in the figure according to sex.Corresponding mography).
correlation coefficients (R) and p values are shown
Patients without contraindications re-
Demographics such as age, gender, the Simplified Acute Physiology Score ceived either low-molecular-weight hep-
body mass index, diagnosis of admission (SAPS II) assessed on the first day [18]. arin (Enoxaparin 40 mg) subcutaneously
and co-existing chronic diseases were once a day or continuous intravenous ad-
identified, as well as duration of ICU Systemic inflammatory response syn- ministration of high-molecular-weight
stay and mortality were recorded. The drome (SIRS), pneumonia, acute re- heparin (200 U/kg per 24 h) in addition
severity of illness was evaluated using nal failure (ARF) demanding renal re- to graded elastic compression stockings
placement therapy, multi-organ failure for thrombosis prophylaxis.

Statistical analysis

All data collected were analyzed using
Student’s t test for continuous variables

102 Medizinische Klinik - Intensivmedizin und Notfallmedizin 2 · 2018

Abstract · Zusammenfassung

Med Klin Intensivmed Notfmed 2018 · 113:101–107 DOI 10.1007/s00063-017-0276-y
© Springer Medizin Verlag GmbH 2017

M. Banach · C. Lautenschläger · P. Kellner · J. Soukup

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

Abstract least one measurement) and control group 95% CI: 1.3–7.2; p = 0.009). Mean duration of
(thrombocytes = 150 – 450 × 109/l during LOS was significantly longer in patients with
Background. Thrombocytosis is a common ICU stay). Univariate and multiple regression thrombocytosis (25.2 vs.11.7 days, p < 0.0001).
phenomenon in critically ill patients. Although analysis were used to determine the influence Elevated platelet count showed a negative
thrombocytosis is an independent risk of severe co-morbidities on the development correlation with ICU mortality (OR: 0.32; 95%-
factor for complications, it does not seem to of thrombocytosis and the association of CI: 0.12–0.83; p = 0.019).
influence mortality in intensive care (ICU) elevated platelet count with thrombotic Conclusion. In our retrospective analysis the
patients. embolism, length of stay (LOS) in ICU, and occurrence of thrombocytosis in a cohort of
Objectives. Our investigation aimed to mortality. interdisciplinary ICU patients was associated
evaluate the etiological and clinical relevance Results. A total of 307 patients were analyzed, with a higher rate of complications and
of a platelet count greater than 450 × 109/l in of whom thrombocytosis was observed in longer LOS in the ICU. Despite these findings,
ICU patients. 119 cases. Independent risk factors for the thrombocytosis seems to reduce mortality in
Materials and methods. Patients admitted for development of thrombocytosis included critical ill patients.
a minimum of 4 days to an interdisciplinary SIRS, mechanical ventilation, and acute
ICU during a 45-month period were enrolled bleeding. Increasing age reduced the risk of Keywords
in this retrospective observational study. thrombocytosis. Thromboembolism occurred Platelets · Thrombocytosis · Intensive care ·
Thrombocytopenic patients (platelet count in 16 patients (13.4%) with an elevated Thrombotic embolism · Mortality
<150 × 109/l in at least one measurement) platelet count and only in nine patients (4.7%)
were excluded. The study patients were with physiological platelet values (OR: 3.1;
divided into two groups: thrombocytosis
group (thrombocytes >450 × 109/l in at

Ätiologie und klinische Bedeutung erhöhter Thrombozytenzahlen bei Intensivpatienten.
Retrospektive Studie

Zusammenfassung auf das Auftreten einer Thrombozytose wesentlich höheren initialen Schwergrad
hin untersucht. Darüber hinaus wurde die der Erkrankung aufwiesen (Simplified
Hintergrund. Eine erhöhte Thrombozytenzahl Assoziation einer erhöhten Thrombozytenzahl Acute Physiology Score II, SAPS II: 55 vs. 49
tritt häufig bei kritisch kranken Patienten auf. in Bezug auf eine Thromboembolie, die Punkte; p < 0,001). In der multifaktoriellen
Obwohl diese als ein Risikofaktor für schwere intensivmedizinische Verweildauer und Regressionsanalyse war die Thrombozytose
Komplikationen betrachtet wird, scheint sie Mortalität evaluiert. signifikant mit einer Risikosenkung der
die Prognose der Intensivpatienten nicht zu Ergebnisse. Ausgewertet wurden die Daten intensivstationären Mortalität assoziiert (OR:
verschlechtern. von 307 Patienten: 119 in der Thrombozyto- 0,32; 95%-KI: 0,12–0,83; p = 0,019).
Fragestellung. Ziel dieser Studie war es, segruppe und 188 in der Kontrollgruppe. Die Schlussfolgerung. Thrombozytose bei
die Ätiologie und klinische Relevanz einer unabhängige Risikofaktoren einer Thrombo- intensivmedizinischen Patienten ist mit einem
Thrombozytenzahl über 450 × 109/l in einem zytose waren: SIRS („systemic inflammatory Auftreten schwerer Komorbiditäten und
intensivmedizinischen Patientenkollektiv zu response syndrome“), Beatmungstherapie, einem erhöhten Risiko venöser Thromboem-
untersuchen. akute Hämorrhagie und geringeres Alter. bolien assoziiert, woraus sich eine verlängerte
Material und Methoden. In diese retrospekti- Eine venöse Thromboembolie trat bei 13,4 % intensivmedizinische Verweildauer ableiten
ve Beobachtungsstudie wurden für einen 45- der Patienten mit Thrombozytose und bei lässt. Hingegen reduziert eine Thrombozytose
monatigen Zeitraum alle Intensivpatienten 4,7 % der Kontrollgruppe auf (Odds Ratio, bei intensivmedizinischen Patienten das
mit einer Verweildauer von mindestens OR: 3,1; 95 %-Konfidenzintervall, 95 %-KI: Mortalitätsrisiko und kann somit als Zusatz-
4 Tagen eingeschlossen. Die Patienten mit 1,3-7,2; p = 0,009). Die durchschnittliche parameter in der Abschätzung des Verlaufs
einer Thrombozytenzahl unter 150 × 109/l Verweildauer auf der Intensivstation war in dienen.
wurden aus der weiteren Analyse ausge- der Thrombozytosegruppe signifikant länger
schlossen. Die evaluierten Patienten wurden als in der Kontrollgruppe (25,2 ± 17,7 vs. Schlüsselwörter
in 2 Gruppen geteilt: Thrombozytosegruppe 11,7 ± 10,4 Tage; p < 0,0001). Die Mortalität Thrombozyten · Thrombozytose · Intensivme-
(Thrombozyten >450 × 109/l in mindestens lag bei 11,7 % in der Thrombozytosegruppe, dizin · Thromboembolie · Mortalität
einer Untersuchung) und Kontrollgruppe verglichen mit 14,9 % in der Kontrollgruppe,
(Thrombozyten: 150 × 109/l bis 450 × wobei die Patienten mit Thrombozytose einen
109/l). Mit univarianten und multiplen
Regressionsanalysen wurden Komorbiditäten

Medizinische Klinik - Intensivmedizin und Notfallmedizin 2 · 2018 103

Originalien

Table 1 Clinical characteristics of the study population elevated platelet count showed one or
more of these potential etiologic condi-
Characteristics Thrombocytosis Control group (n = p tions before or during the occurrence
group (n = 119) 188) of thrombocytosis. Furthermore, the
0.001 necessity of mechanical ventilation (95%
Age (years ± SD) 56.8 ± 19.7 63.6 ± 16.3 0.094 vs. 83.5%, p = 0.003) and the ventilation
time (16.2 ± 16.12 vs. 6.8 ± 9.3 days,
Sex: n (%) Male: 73 (61%) Male: 97 (52%) 0.172 p < 0.001) were significantly associated
BMI (kg/m2±SD) Female: 46 (39%) Female: 91 (48%) <0.001 with thrombocytosis, compared with
the control group. Univariate regression
26.1 ± 5.0 27.4 ± 9.7 0.72 analysis indicated a significantly higher
0.26 risk of thrombocytosis for SIRS, pneumo-
SAPS II score at admission 55.48 ± 15.1 49.13 ± 18.2 0.57 nia, ARF, DIC, MOF, hemorrhage, and
0.10 the duration of mechanical ventilation.
Admission category 0.66 Further analysis using multiple logistic
regressions revealed SIRS (OR: 2.5; 95%
Neurosurgery 48 (40%) 80 (42%) 0.15 CI: 1.29–5.03; p = 0.007), hemorrhage
Major trauma 17 (14%) 18 (10%) 0.21 (OR: 2.7; 95% CI: 1.13–6.78; p = 0.025),
Sepsis 15 (12%) 19 (10%) >0.99 and duration of mechanical ventilation
Elective postoperative 13 (10%) 34 (18%) 0.13 (OR: 1.057 for each additional day; 95%
Medical 26 (21%) 37 (19%) 0.38 CI: 1.028–1.087; p < 0.001) as indepen-
0.64 dent risk factors for the development of
Co-existing diseases 0.57 thrombocytosis. DIC non-significantly
0.27 increased the risk of thrombocytosis
Arterial hypertension 61 (51%) 113 (60%) 0.09 more than threefold (OR: 3.3; 95% CI:
Hypertensive crisis 4 (3%) 13 (7%) 0.49–22.22; p = 0.21), probably due to
Lung diseases 16 (13%) 26 (13%) a relative low number of patients (n =
Platelet inhibitor therapy 8 (6%) 31 (16%) 10) with this disorder. The relationship
Blood diseases 1 (0.8%) 0 between the aforementioned factors and
Auto-immune disorders 2 (1.6%) 2 (1%) disorders and the risk of thrombocytosis
Diabetes mellitus 25 (21%) 45 (24%) is shown in . Fig. 3a, b.
Neoplasm 25 (21%) 50 (26%)
History of splenectomy 3 (2%) 1 (0.5%) Side effects

Absolute count, relative percentages, and p values are given in the table Thromboembolism
n number of patients, SAPS II Simplified Acute Physiology Score, BMI body mass index
In all, 16 patients (13.4%) in the thrombo-
and the chi-squared test or Fisher’s ex- (±5.0; range 1–39). The average onset day cytosis group and only 9 patients (4.7%)
act test for categorical variables. Uni- of thrombocytosis was the 12th day after in the control group developed symp-
variate and multiple logistic regression ICU admission ranging between day 0 tomatic thromboembolic complications.
analysis was used to determine the odds and day 43, whereas 80% of these patients Univariate analysis revealed a significant
ratio (OR) and corresponding 95% con- (n = 95) developed thrombocytosis after connection between elevated platelet
fidence interval (CI) of selected factors 4 days of ICU stay. count in at least one measurement and
associated with thrombocytosis, throm- development of deep vein thrombosis
botic embolism, and ICU mortality. Data No differences were revealed between or pulmonary embolism (OR: 3.1; 95%
are expressed as frequency for categorical the thrombocytosis group and the control CI: 1.3–7.2; p = 0.009). Further anal-
variables and as mean and standard de- group in terms of gender, BMI, cause of ysis using multiple logistic regressions
viation (±SD) for continuous variables. admission and pre-existing chronic dis- showed a nonsignificant increase in the
Statistical significance was set at p < 0.05. eases. The average age of patients with risk for thrombotic embolism by the
Data were analyzed using SPSS Statistics thrombocytosis was significantly lower occurrence of thrombocytosis (OR: 1.9;
version 19 (SPSS software, IBM Corp., (56.8 ± 19.7 vs. 63.6 ± 16.3 years, p = 95% CI: 0.7–5.3; p = 0.2). The highest
Armonk, N.Y.). 0.001) and the risk of thrombocytosis and statistically significant impact for
decreased with age, as demonstrated in increased thromboembolism risk was
Results . Fig. 2. Patients with a platelet count seen in DIC patients (OR: 8.1; 95% CI:
over 450 × 109/l in at least one measure- 1.4–46.2; p = 0.018).
During the analyzed time period, 752 pa- ment had a significantly higher severity
tients were admitted to the ICU for 4 days of illness score (SAPS II) 24 h after ad-
or more. A total of 445 patients with mission (55.48 ± 15.1 vs. 49.13 ± 18.2,
platelet counts lower than 150 × 109/l in p < 0.001).
at least one measurement were excluded
from further analysis. Consequently, the Risk factors associated with the
final study population included 307 pa- development of thrombocytosis
tients of whom thrombocytosis was ob-
served in 119 cases (. Fig. 1). The patient The results of univariate analysis for
characteristics are given in . Table 1. the incidence of severe co-morbidities,
the duration of mechanical ventilation,
In the thrombocytosis group, platelet and their relation to thrombocytosis are
count exceeded 450 × 109/l for 5 days given in . Table 2. All patients with an

104 Medizinische Klinik - Intensivmedizin und Notfallmedizin 2 · 2018

Table 2 Univariate analysis of etiologic conditions associated with thrombocytosis bopoietin, interleukin-6, interleukin-11,
tumor necrosis factor, as well as endoge-
Overall Patients with Patients with- p OR 95% CI nous catecholamines [9, 15, 27, 37]. SIRS
num- thrombocyto- out throm- is mostly provoked by severe infections
ber of sis (n (%)) bocytosis or extensive operative or traumatic tis-
patients (n (%)) sue damages [6]. In our study, pneumo-
nia was the most frequent cause of SIRS.
SIRS 104 64 (62) 40 (38) <0.001 4.3 2.61–7.11 According to the literature, an infectious
process is indeed the most common cause
Pneumonia 124 69 (56) 55 (44) <0.001 3.3 2.06–5.4 of reactive thrombocytosis [11, 33], most
often explained by SIRS. Additionally,
Mechanical 270 16.2 ± 16.12 6.87 ± 9.31 <0.001 1.07 1.04–1.10 the duration of mechanical ventilation
ventilation (n = 113) (n = 157) showed a significant positive correlation
(duration; with an elevated platelet count in our
days±SD) study, with an increased risk of reactive
thrombocytosis of about 6–7.5%/day of
ARF 23 17 (74) 6 (26) 0.001 5.05 1.93–13.22 mechanical ventilation. Definitely, posi-
tive pressure ventilation provokes a pul-
DIC 10 8 (80) 2 (20) 0.017 6.7 1.39–32.12 monary and systemic inflammatory reac-
tion with high levels of interleukin-6, -8,
MOF 29 20 (69) 9 (31) 0.001 4.02 1.76–9.16 and -10 in the bronchoalveolar lavage
fluid and plasma of ventilated patients
Hemorrhage 32 20 (63) 12 (37) 0.005 2.9 1.39–6.31 [20, 34, 35], which again induces the el-
evation of platelets. Mechanical ventila-
CPR 16 7 (44) 9 (56) 0.67 1.2 0.45–3.43 tion was identified as an independent risk
factor for secondary thrombocytosis in
Absolute count, relative percentages, and p values are given in the table trauma patients by Salim and colleagues
OR odds ratio, CI confidence interval, SIRS systemic inflammatory response syndrome, ARF acute [26], but to date no study had analyzed the
renal failure, DIC disseminated intravascular coagulation, MOF multi-organ failure, CPR cardiopul- influence of the duration of ventilation.
monary resuscitation Furthermore, our findings demonstrated
that acute bleeding increased the risk of
Length of stay Discussion thrombocytosis. This could be explained
by the enhanced synthesis and release
Mean duration of ICU stay was significant Thrombocytosis, defined as an excessive of thrombopoietin as a feedback mecha-
longer in patients with thrombocytosis number of blood platelets, is a com- nism of the increased platelet loss during
compared with the control group (25.2 ± mon phenomenon in ICU patients. In bleeding [17]. Possibly, ARF and DIC
17.7 vs. 11.7 ± 10.4 days, p < 0.0001). this study we demonstrated that elevated also increase the risk of thrombocytosis,
Within the thrombocytosis group, the platelet count in an ICU population was but in our patient cohort only a small
prevalence was significantly higher in associated with specific co-morbidities as number of patients suffered from these
patients with late-onset thrombocytosis well as with the duration of mechanical disorders, leading to a nonsignificant ef-
(>4 days from admission) compared with ventilation, leading to an increased risk of fect after correcting for this in the multi-
patients with early-onset thrombocyto- thromboembolic complications and pro- ple regression analysis. According to our
sis (27 ± 17.0 vs. 16 ± 18.2 days, p = longed ICU stay. Despite these findings, results, the risk of reactive platelet ele-
0.009). Additionally, patients with a du- thrombocytosis decreased the risk of ICU vation decreased with age, which could
ration of thrombocytosis of more than mortality and appeared to be a predictor be an explanation for the fact that only
5 days showed a significantly longer ICU of a favorable outcome. a few patients with predisposing factors
LOS (31 ± 20 vs. 21 ± 15.2 days, p < developed thrombocytosis.
0.001). Increased platelet count can be either
primary or secondary (reactive) to a vari- Similar to other studies in trauma,
Outcome ety of conditions [27]. Primary thrombo- postoperative, and medical patients [10,
cytosis is a frequent event in general hos- 13, 14, 16, 22, 26], we demonstrated that
Overall ICU mortality was 11.7% in pa- pital populations. By contrast, elevated a platelet count greater than 450 × 109/l in
tients with thrombocytosis and 14.9% in platelet count in ICU patients usually at least one measurement was associated
the control group (n. s.). In this context, represents a reactive phenomenon [23, with a higher rate of thromboembolic
the univariate analysis revealed a ten- 33], occurring prior to ICU admission complications. Moreover, the prevalence
dency toward a reduction in the mor- or developing during the ICU stay. The of deep vein thrombosis or pulmonary
tality risk of about 24% when thrombo- majority (80%) of patients in our analysis embolism in our study in a heteroge-
cytosis was evident (OR: 0.76; 95% CI: developed thrombocytosis after 4 days of
0.38–1.5; p = 0.44). After adjusting for ICU stay and only 20% patient had an
the SAPS II score, which was significantly elevated platelet count within the first
higher in patients with elevated platelet 4 days of admission. The development
count, occurrence of thrombocytosis de- of SIRS was the leading cause of thrombo-
creased mortality risk by 42% (OR: 0.58; cytosis in our investigation. This reactive
95% CI: 0.28–1.2; p = 0.14). In multiple thrombocytosis could be interpreted as
logistic regression analysis, thrombocy- part of the acute-phase response that has
tosis significantly and independently re- been shown to be mediated by various
duced the risk of mortality (OR: 32; 95% humoral substances, especially throm-
CI: 0.12–0.83; p = 0.019).

Medizinische Klinik - Intensivmedizin und Notfallmedizin 2 · 2018 105

Originalien

integrity of endothelial cell membranes
with a reduction in vascular permeabil-
ity [2, 38]. Furthermore, a potential me-
diatory role in inflammatory processes
and host defense mechanisms as well as
participating in wound healing and vas-
cular remodeling is postulated [24, 38].
Currently, the question of whether and
how the use of the platelet inhibitors in
critically ill patients could influence the
course of disease is being investigated [3].

Study limitations

Fig. 3 8 Odds ratios of factors associated with thrombocytosis. Odds ratios for duration of mechanical Our study has a number of shortcomings.
ventilation, age, body mass index (BMI, a) as well as systemic inflammatory response syndrome (SIRS), First, it is a single-center and retrospec-
pneumonia, acute renal failure (ARF), disseminated intravascular coagulation (DIC), hemorrhage and tive study and, therefore, further confir-
cardiopulmonary resuscitation (CPR, b) in relation to thrombocytosis. Values were initially identified mations of our results in other prospec-
using univariate regression analysis followed by multiple logistic regression analysis and are presented tive investigations are required. Second,
including 95% confidence intervals (CI) together with corresponding pvalues the patients included were only followed
up until discharge from the ICU – in part
neous ICU population was 13.4% in pa- 36]. We analyzed the data in compari- – with a persistent thrombocytosis. In
tients with thrombocytosis and therefore son with a control group with a normal future it would be interesting to follow
almost two times higher than previously platelet count throughout. After consid- up these patients in order to assess the
reported in trauma patients (4.6–8%) [16, ering the co-morbidities, age, BMI, and complications and mortality after ICU
26]. One reason for this difference may severity of illness score in our patient or hospital discharge. Furthermore, in
be divergent inclusion criteria. We ex- cohort, the occurrence of thrombocyto- critically ill patients various confounding
cluded patients with an ICU stay of less sis significant decreased the risk of ICU factors are present and it is not possible
than 4 days, leading to the selection of mortality, regardless of an existing higher to control for all of them and take all of
a more severe cohort, as documented by severity of illness score or rate throm- them into consideration. To minimize
higher SAPS II scores in contrast to the boembolic complications. Similar results these effects, we conducted a multiple
cited investigations. On the other hand, were reported by Salim and colleagues, regression analysis apart from univariate
our patients with thrombocytosis poten- showing a significant lower mortality in analysis. Owing to the limited number
tially suffered from a higher rate of co- spite of a simultaneously higher throm- of patients, the impact of certain factors
morbidities and thromboembolic com- botic embolism rate in patients with post- and disorders could not be adequately
plications, which could be a reason for traumatic elevated platelet count [26]. It analyzed, thereby limiting the precision
the prolonged ICU stay. This was ex- seems that platelets may have both bene- of the results and the power of the study.
plicitly seen in patients who developed ficial and potentially harmful effects. In- Finally, the treatment strategies that are
thrombocytosis after 4 days of ICU ad- creased platelet production and aggre- permanently developed may have a big
mission and long-lasting higher platelet gation in inflammation combined with impact on disease progression and out-
count. an increased production of inflamma- come.
tory mediators impairs microcirculatory
Gurung et al. reported that an elevated blood flow and participates in organ dys- Conclusion
platelet count correlates with increased function and failure [8, 24, 25]. The ben-
survival in the ICU, compared with both eficial effect of reactive thrombocytosis In conclusion, thrombocytosis presents
thrombocytopenia and normal platelet on clinical outcome in critically ill pa- a frequent and remarkable symptom in
count [12]. In our study we did not con- tients seems to be associated with the the course of critical illness. The indepen-
sider thrombocytopenia, which is known protective influence of platelets on the dent predictors for elevation of platelet
to correlate with poor outcome [1, 30, count found in our investigation were
SIRS, mechanical ventilation, and acute
bleeding. Patients with thrombocytosis
presented with more organ failures and
thromboembolic complications as well
as a longer ICU stay. Nonetheless, the
occurrence of thrombocytosis seems to
reduce the risk of ICU mortality.

106 Medizinische Klinik - Intensivmedizin und Notfallmedizin 2 · 2018

Corresponding address 11. Griesshammer M, Bangerter M, Sauer T et al 31. Tchebiner JZ, Nutman A, Boursi B et al (2011)
(1999) Aetiology and clinical significance of Diagnostic and prognostic value of thrombocytosis
Dr. P. Kellner thrombocytosis: analysis of 732 patients with an in admitted medical patients. Am J Med Sci
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