Temporal changes in hematologic markers after splenectomy, splenic embolization, and observation for trauma

Initial Hemorrhage Control Procedure for Splenic Injuries May Affect Risk of Venous Thromboembolism

INTRODUCTION

Venous thromboembolism (VTE) continues to be a major cause of morbidity in trauma. It is unclear whether the type of hemorrhage control procedure (i.e., splenectomy versus angioembolization) is associated with an increased risk of VTE. We hypothesize that hemodynamically stable patients undergoing angioembolization for blunt high-grade splenic injuries have lower rates of VTE compared to those undergoing splenectomy.

METHODS

The American College of Surgeons Trauma Quality Program dataset from 2017 to 2019 was queried to identify all patients with American Association for the Surgery of Trauma grade 3-5 blunt splenic injuries. Outcomes including VTE rates were compared between those who were managed with splenectomy versus angioembolization. Propensity score matching (1:1) was performed adjusting for age, sex, initial vital signs, Injury Severity Score, and splenic injury grade.

RESULTS

The analysis included 4698 matched patients (splenectomy [n = 2349] and angioembolization [n = 2349]). The median (interquartile range) age was 41 (27-58) years and 69% were male. Patients were well matched between groups. Angioembolization was associated with significantly lower VTE than splenectomy (2.2% versus 3.4%, P = 0.010) despite less use of VTE chemoprophylaxis (70% versus 80%, P < 0.001), as well as a relative delay in initiation of chemoprophylaxis (44 h versus 33 h, P < 0.001). Hospital and intensive care unit length of stay and mortality were also significantly lower in the angioembolization group.

CONCLUSIONS

Angioembolization is associated with a significantly lower incidence of VTE than splenectomy. Thus, angioembolization should be considered for initial management of hemodynamically stable patients with high-grade blunt splenic injuries in whom laparotomy is not otherwise indicated.

Hematologic setpoints are a stable and patient-specific deep phenotype

The complete blood count is an important screening tool for healthy adults and is the most commonly ordered test at periodic physical exams. However, results are usually interpreted relative to one-size-fits-all reference intervals, undermining the goal of precision medicine to tailor medical care to the needs of individual patients based on their unique characteristics. Here we show that standard complete blood count indices in healthy adults have robust homeostatic setpoints that are patient-specific and stable, with the typical healthy adult's set of 9 blood count setpoints distinguishable from 98% of others, and with these differences persisting for decades. These setpoints reflect a deep physiologic phenotype, enabling improved detection of both acquired and genetic determinants of hematologic regulation, including discovery of multiple novel loci via GWAS analyses. Patient-specific reference intervals derived from setpoints enable more accurate personalized risk assessment, and the setpoints themselves are significantly correlated with mortality risk, providing new opportunities to enhance patient-specific screening and early intervention. This study shows complete blood count setpoints are sufficiently stable and patient-specific to help realize the promise of precision medicine for healthy adults.

Follow-up strategies for patients with splenic trauma managed non-operatively: the 2022 World Society of Emergency Surgery consensus document

Background

In 2017, the World Society of Emergency Surgery published its guidelines for the management of adult and pediatric patients with splenic trauma. Several issues regarding the follow-up of patients with splenic injuries treated with NOM remained unsolved.

Methods

Using a modified Delphi method, we sought to explore ongoing areas of controversy in the NOM of splenic trauma and reach a consensus among a group of 48 international experts from five continents (Africa, Europe, Asia, Oceania, America) concerning optimal follow-up strategies in patients with splenic injuries treated with NOM.

Results

Consensus was reached on eleven clinical research questions and 28 recommendations with an agreement rate ≥ 80%. Mobilization after 24 h in low-grade splenic trauma patients (WSES Class I, AAST Grades I–II) was suggested, while in patients with high-grade splenic injuries (WSES Classes II–III, AAST Grades III–V), if no other contraindications to early mobilization exist, safe mobilization of the patient when three successive hemoglobins 8 h apart after the first are within 10% of each other was considered safe according to the panel. The panel suggests adult patients to be admitted to hospital for 1 day (for low-grade splenic injuries—WSES Class I, AAST Grades I–II) to 3 days (for high-grade splenic injuries—WSES Classes II–III, AAST Grades III–V), with those with high-grade injuries requiring admission to a monitored setting. In the absence of specific complications, the panel suggests DVT and VTE prophylaxis with LMWH to be started within 48–72 h from hospital admission. The panel suggests splenic artery embolization (SAE) as the first-line intervention in patients with hemodynamic stability and arterial blush on CT scan, irrespective of injury grade. Regarding patients with WSES Class II blunt splenic injuries (AAST Grade III) without contrast extravasation, a low threshold for SAE has been suggested in the presence of risk factors for NOM failure. The panel also suggested angiography and eventual SAE in all hemodynamically stable adult patients with WSES Class III injuries (AAST Grades IV–V), even in the absence of CT blush, especially when concomitant surgery that requires change of position is needed. Follow-up imaging with contrast-enhanced ultrasound/CT scan in 48–72 h post-admission of trauma in splenic injuries WSES Class II (AAST Grade III) or higher treated with NOM was considered the best strategy for timely detection of vascular complications.

Conclusion

This consensus document could help guide future prospective studies aiming at validating the suggested strategies through the implementation of prospective trauma databases and the subsequent production of internationally endorsed guidelines on the issue.

Impact of blood alcohol concentration on hematologic and serum chemistry parameters in trauma patients: Analysis of data from a high-volume level 1 trauma center

Background

Alcohol (EtOH) intoxication is common among trauma patients. While providers are familiar with the clinical aspects of acute EtOH intoxication, few studies have investigated the effects that EtOH levels may have on common laboratory markers. The aim of this study was to identify hematologic and serum chemistry parameters that may be affected by the blood alcohol concentration (BAC), hypothesizing that BAC influences both comprehensive blood count (CBC) and comprehensive serum chemistry (CSC) components.

Methods

We performed an IRB-exempt institutional registry review of all trauma patients who had serum EtOH levels measured between January 2009 and June 2015. Data for each patient included: patient demographics, BAC determinations (g/dL), injury mechanism/severity information (ISS), hematologic parameters included in a CBC (hemoglobin, hematocrit, white blood cell [WBC] count, and platelet count), and CSC panel components (sodium, potassium, chloride, bicarbonate, blood urea nitrogen [BUN], creatinine, glucose, and hepatic function tests). Laboratory markers were contrasted across predefined categories of BAC: <0.10%, 10%-15%, 15%-20%, and >20%. Statistical comparisons were performed using SPSS 18 Software, employing analysis-of-covariance with adjustments performed for the patient demographics and injury characteristics. Statistical significance was set at α = 0.005.

Results

A total of 2167 patient records were analyzed. After adjusting for patient age, gender, and ISS, increasing BAC correlated with 4.8% increase in hemoglobin and 32.5% higher hematocrit (both P < 0.001), as well as a 27.8% decrease in WBC count. There were also statistically significant differences between low (<0.10%) and high (>0.20%) BAC groups across multiple CSC parameters, with largest impact on BUN (32.2% decrease); creatinine (31.5% decrease); and glucose (13.6% decrease) values. Elevated BAC (>0.20 g/dL) was also associated with 81.8% increase in total bilirubin, and hepatic transaminases were elevated among patients with BAC >0.10.

Conclusion

Due to the paucity of literature relating to the effects of BAC on serum hematologic and biochemical markers in acute trauma, this study provides a foundation for further exploration of these relationships and their clinical impact. More specifically, we found that BAC levels significantly influenced key laboratory markers, suggesting that acute EtOH intoxication may lead to hematologic and CSC changes that are potentially important in acute trauma management by frontline clinical staff.

Splenic Artery Angioembolization is Associated with Increased Venous Thromboembolism

BACKGROUND

Angioembolization has become an increasingly utilized adjunct for splenic preservation after trauma. Embolization of the splenic artery may produce a transient systemic hypercoagulable state. This study was designed to determine the risk of venous thromboembolism (VTE) in blunt trauma patients managed nonoperatively with splenic angioembolization, relative to those managed without.

METHOD

Retrospective review of the American College of Surgeons Trauma Quality Improvement Performance (TQIP) Database from 2013 to 2016. Adult (>16 years) patients with isolated, severe (Grades III-V) blunt splenic injuries managed nonoperatively who received pharmacological VTE prophylaxis formed the study population. Outcomes included deep venous thrombosis (DVT), pulmonary embolism (PE), or any VTE.

RESULTS

A total of 2643 patients met inclusion criteria (69.1% Grade III, 26.5% Grade IV, 4.5% Grade V). The incidence of DVT was 4.5% in patients who underwent angioembolization, compared to 1.4% in patients who did not (p<0.001). Multivariable analysis showed that angioembolization was an independent risk factor for both DVT (OR 2.65, p = 0.006) and any VTE (OR 2.04, p = 0.01). Analysis according to splenic injury Grades showed that angioembolization remained an independent risk factor for DVT (p = 0.004) in the Grade IV-V injury group, and for VTE (p<0.01) in the Grade III injury group. Initiation of pharmacological VTE prophylaxis 48 h after admission was associated with increased VTE rates in comparison to early initiation (OR 1.75, p = 0.02) CONCLUSIONS: Splenic artery angioembolization may be an independent risk factor for VTE events in isolated, severe blunt splenic trauma managed nonoperatively. Early prophylaxis with LMWH after intervention should be strongly considered.

Diagnostic and predictive value of white blood cell count, erythrocyte sedimentation rate, and coagulation tests in patients with blunt head trauma

Introduction: Head trauma is the third leading cause of death and one of the most common causes of referral to the emergency department. Prognosis in these patients identifies individuals at higher risk and provides them with faster and more complete treatment, so it is of particular importance. The aim of this study is to evaluate the diagnostic and predictive value of white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and coagulation tests in the outcome of patients with blunt head trauma. Methods: In this retrospective study, 91 patients referred to the emergency department of Imam Reza hospital of Tabriz, with a complaint of DAI type of blunt head trauma, were enrolled in a complete and sequential study during the first six months of the year 2017. The patientswere divided into two groups according to good or poor prognosis and their association with leukocytosis status and other paraclinical factors at the baseline. Results: The final outcome in high consciousness group was 13.3% need for intubation,26.7% need for surgery, 50% improvement without complications, and 10% mortality. In the low consciousness group, 16.7% required intubation, 20.0% required surgery, 10% had no complications, and 53.3% experienced mortality. The significance level of the chi-squaretest was 0.001. Independent t test results showed that the WBC and ESR values in the lowconsciousness group were significantly higher than the high consciousness group. But the international normalized ratio (INR) in the high consciousness group was significantly higher than the low consciousness group (P<0.05). Conclusion: There is a significant relationship between severity of injury and leukocytosis, ESRelevation, and related coagulopathy after major trauma.

Trends in hematologic markers after blunt splenic trauma: Risk factor or Epiphenomenon?

BACKGROUND

Most blunt splenic injuries (BSI) are treated with nonoperative management (NOM) or embolization (EMBO). Little is known about the hematologic changes associated with these treatments. We aim to assess the temporal changes of hematologic markers in trauma patients who undergo splenectomy (SPL), packing and splenorrhaphy (P/S), EMBO, or NOM. We hypothesize that differences in trends of hematologic markers exist in patients undergoing EMBO or SPL, compared to NOM.

METHODS

An 8-year review of adult patients with BSI and underwent SPL, EMBO, P/S, or NOM. White blood cell count (WBC), hematocrit (HCT) and platelet count (PLT) at presentation to 14 days post-admission were analyzed; post-procedural complications were reviewed. Temporal trends were compared using linear mixed-effects models.

RESULTS

478 patients sustained BSI, 298 (62.3%) underwent NOM, 100 (29.2%) SPL, 42 (8.8%) EMBO, and 38 (8.0%) P/S. After adjustment for age, ISS and splenic injury grade, SPL patients had a significantly higher upward trend compared to other management strategies (p < 0.05). Infection further increased this trend. Starting on day 6, SPL patients with infections had significantly higher WBC than those without infection. SPL and P/S were more likely than NOM to develop infections after adjustment for confounders (HR = 3.64; 95%CI: 1.79-7.39 and HR = 2.59; 95%CI: 1.21-5.55, respectively). Day 6 WBC>16,000 cells/ml post-SPL had a positive predictive value (PPV) of 65.2% and negative predictive value (NPV) of 76.9% for infections. Among P/S, Day 6 WBC >10,200 cells/ml had a PPV = 50% and NPV = 86.7% for infections.

CONCLUSIONS

We observed distinct patterns of hematologic markers following BSI managed with SPL, EMBO, P/S, and NOM. Day 6 WBC increases after SPL or P/S should raise suspicion of infections and trigger a diagnostic investigation.

Clinical and laboratory assessment of a patient with thrombocytosis

Elevated platelet counts are frequently encountered in hospital medicine and arise from both physiological and pathological mechanisms. Thrombocytosis may be secondary, reflecting an inflammatory state, iron deficiency, recent surgery or point towards an underlying neoplasm. Thrombocytosis may be the presenting sign of solid tumours and haematological conditions. The discovery of the activating mutations affecting thrombopoiesis led to greater understanding of the pathobiology of essential thrombocythaemia and other myeloproliferative neoplasms. The investigation of suspected primary thrombocytosis has evolved to include testing for these disease-associated mutations. Therapy for patients with essential thrombocythaemia aims to reduce their risk of thrombotic complications by addressing cardiovascular risk factors, and using antiplatelet agents and, in selected patients, cytoreductive therapy. This article provides a logical approach to distinguishing reactive or secondary thrombocytosis from thrombocytosis associated with an underlying myeloproliferative neoplasm and gives an overview of the management of essential thrombocythaemia.

Increased Hematocrit Due to Electrical-Waveform Exposures in Splenectomized Sus scrofa

In laboratory studies of the pig Sus scrofa, hematocrit has consistently increased after conducted-electrical-weapon (CEW) exposures, possibly due to contraction of the spleen. Splenectomized animals and intact sham control animals were exposed, each for 30 sec, to a benchtop-produced electrical waveform of net charge levels similar to those of some CEWs. Changes in the blood were compared statistically. Hematocrit increased significantly in both splenectomized and sham animals. There were no significant main-effect differences between values of hematocrit from the two groups. There were, however, significant interactive effects of time and splenectomy for hematocrit, red blood cell count, and hemoglobin. After peak values were reached for these variables, values returned toward baseline levels more slowly in splenectomized animals. This may have been due to the lack of a spleen to sequester red blood cells (thereby resulting in more cells remaining in the general circulation), unlike sham animals with intact spleens.

Long-Term Follow-Up After Non-operative Management of Blunt Splenic and Liver Injuries: A Questionnaire-Based Survey

BACKGROUND

Non-operative management (NOM) of blunt splenic or liver injuries (solid organ injury, SOI) has become the standard of care in hemodynamically stable patients. However, the incidence of long-term symptoms in these patients is currently not known. The aim of this study was to assess long-term symptoms in patients undergoing successful NOM (sNOM) for SOI.

METHODS

Long-term posttraumatic outcomes including chronic abdominal pain, irregular bowel movements, and recurrent infections were assessed using a specifically designed questionnaire and analyzed by univariable analysis.

RESULTS

Eighty out of 138 (58%) patients with SOI undergoing sNOM) responded to the questionnaire. Median (IQR) follow-up time was 48.8 (28) months. Twenty-seven (34%) patients complained of at least one of the following symptoms: 17 (53%) chronic abdominal pain, 13 (41%) irregular bowel movements, and 8 (25%) recurrent infections. One female patient reported secondary infertility. No significant association between the above-mentioned symptoms and the Injury Severity Score, amount of hemoperitoneum, or high-grade SOI was found. Patients with chronic pain were significantly younger than asymptomatic patients (32.1 ± 14.5 vs. 48.3 ± 19.4 years, p = 0.002). Irregular bowel movements were significantly more frequent in patients with severe pelvic fractures (15.4 vs. 0.0%, p = 0.025). A trend toward a higher frequency of recurrent infections was found in patients with splenic injuries (15.9 vs. 2.8%, p = 0.067).

CONCLUSION

A third of patients with blunt SOI undergoing sNOM reported long-term abdominal symptoms. Younger age was associated with chronic abdominal symptoms. More studies are warranted to investigate long-term outcomes immunologic sequelae in patients after sNOM for SOI.

Red Blood Cell Homeostasis: Mechanisms and Effects of Microvesicle Generation in Health and Disease

Red blood cells (RBCs) generate microvesicles to remove damaged cell constituents such as oxidized hemoglobin and damaged membrane constituents, and thereby prolong their lifespan. Damage to hemoglobin, in combination with altered phosphorylation of membrane proteins such as band 3, lead to a weakening of the binding between the lipid bilayer and the cytoskeleton, and thereby to membrane budding and microparticle shedding. Microvesicle generation is disturbed in patients with RBC-centered diseases, such as sickle cell disease, glucose 6-phosphate dehydrogenase deficiency, spherocytosis or malaria. A disturbance of the membrane-cytoskeleton interaction is likely to be the main underlying mechanism, as is supported by data obtained from RBCs stored in blood bank conditions. A detailed proteomic, lipidomic and immunogenic comparison of microvesicles derived from different sources is essential in the identification of the processes that trigger vesicle generation. The contribution of RBC-derived microvesicles to inflammation, thrombosis and autoimmune reactions emphasizes the need for a better understanding of the mechanisms and consequences of microvesicle generation.

Changes of red blood cell aggregation parameters in a long-term follow-up of splenectomy, spleen-autotransplantation and partial or subtotal spleen resections in a canine model

BACKGROUND

Decrease or loss in splenic filtration function may influence the hemorheological state.

OBJECTIVE

To follow-up the long-term effects of splenectomy, spleen autotransplantation and spleen resections on red blood cell aggregation in a canine model.

METHODS

Beagle dogs were subjected to control (n = 6), splenectomy (SE, n = 4), spleen autotransplantation (AU, Furka's spleen-chip method, n = 8) or partial and subtotal spleen resection (n = 4/each) groups, and followed-up for 18 postoperative (p.o.) months. Erythrocyte aggregation was determined in parallel by light-transmittance aggregometry (Myrenne MA-1 aggregometer) and syllectometry (LoRRca).

RESULTS

Erythrocyte aggregation decreased three months after splenectomy, with lower aggregation index and elongated aggregation time. It was more or less associated with relatively lower hematocrit and fibrinogen concentration. However, in autotransplantated animals a relatively higher fibrinogen did not increase the aggregation markedly. Spleen resection resulted in the most controversial red blood cell aggregation findings, and it seems, that the degree of the resection is an influencing factor.

CONCLUSIONS

Splenectomy alters erythrocyte aggregation, spleen autotransplantation can be useful to preserve filtration function. However, the degree of restoration shows individual differences with a kind of 'functional periodicity'. Spleen resection controversially influences erythrocyte aggregation parameters. The subtotal resection is supposed to be worse than spleen autotransplantation.