A practical approach to evaluating postoperative thrombocytopenia. Blood Adv. 2020;4:776-783. [PMID: 32097460 DOI: 10.1182/bloodadvances.2019001414]

Postoperative Spinal Cord Ischemia Monitoring: A Review of Techniques Available after Endovascular Aortic Repair

BACKGROUND

Spinal cord ischemia is one of the complications that can occur after open and endovascular thoracoabdominal aortic repair. This occurs despite various perioperative approaches, including distal aortic perfusion, hybrid procedures with extra anatomical bypasses, motor-evoked potential, and cerebrospinal fluid drainage. The inability to recognize spinal ischemia in a timely manner remains a devastating complication after thoracoabdominal aortic repair.This review aims to look at novel technologies that are designed for continuous monitoring to detect early changes that signal the development of spinal cord ischemia and to discuss their benefits and limitations.

METHODS

We conducted a systematic review of the technologies available for continuous monitoring in the intensive care unit for early detection of spinal cord ischemia. Studies were eligible for inclusion if they used different technologies for monitoring spinal ischemia during the postoperative period. All articles that were not available in English were excluded. To ensure that all relevant articles were included, no other significant restrictions were imposed.

RESULTS

We identified 59 studies from the outset to December 2022 to be included in our study. New techniques have been studied as potentially useful monitoring tools that could provide simple and effective monitoring of the spinal cord. These include near-infrared spectroscopy, contrast-enhanced ultrasound, magnetic resonance imaging, fiber optic monitoring of the spinal cord, and cerebrospinal fluid biomarkers.

CONCLUSIONS

Despite the development of new techniques to monitor for postoperative spinal cord ischemia, their use remains limited. We recommend more future research to ensure rapid intervention for our patients.

In-Vivo Evaluation of a Novel Integrated Pediatric Pump Lung in a 30-Day Ovine Animal Model

Recently there has been increased use of mechanical circulatory support in pediatric patients as a bridge to cardiopulmonary recovery or transplantation. However, there are few devices that are optimized and approved for use in pediatric patients. We designed and prototyped a novel integrated pediatric pump lung (PPL) that underwent 30 day in-vivo testing in seven juvenile Dorset Hybrid sheep. Devices were implanted in a right atrial to pulmonary artery configuration. Six of seven sheep survived with a device functioning for 25-35 days. The device flow rate was maintained at 2.08 ± 0.34 to 2.54 ± 0.16 L/min with oxygen transfer of 109.8 ± 24.8 to 151.2 ± 26.2 ml/min over the study duration. Aside from a postoperative drop in hematocrit, all hematologic and blood chemistry test values returned to normal ranges after 1-2 weeks postoperatively. Similarly, lactate dehydrogenase increased postoperatively and returned to baseline. In two sheep, there were early device failures due to oxygenator thrombosis on postoperative days zero and five; they then had oxygenator exchanges with subsequent devices performing stably for 30 days. This study demonstrated that the integrated PPL device exhibited stable performance and acceptable biocompatibility in a 30 day ovine model.

An Introduction to the Complete Blood Count for Clinical Chemists: Platelets

BACKGROUND

The most ordered laboratory test worldwide is the complete blood count (CBC).

CONTENT

In this primer, an introduction to platelet testing in the context of the CBC is provided with a discussion of the laboratory evaluation of platelet abnormalities including thrombocytopenia and thrombocytosis.

SUMMARY

As clinical chemists continue to be tasked to direct laboratories outside of the traditional clinical chemistry sections such as hematology, expertise must be developed. This primer is dedicated to that effort.

Intraoperative Oxygen Consumption and Postoperative Immune Response in Colorectal Oncological Surgery: A Prospective, Monocentric Pilot Study

Surgical resection is the key treatment for colorectal cancer, but the extent of surgical trauma has been implied as a key factor for the oncologic outcome. The immune stress response to surgical trauma generates a cascade of immunological events implying neutrophils' perioperative change generating NETosis, N killer decrease, and platelets' activation that may influence postoperative surgical outcome, tumor cell growth, and future oncogenesis. The present study aimed to investigate the correlation between intraoperative oxygen consumption (VO2) and the dynamic variation of neutrophils, lymphocytes, and platelets in the perioperative period to identify an intraoperative tool that could predict the postoperative immune response. Twenty-six colorectal oncological surgical patients were enrolled in an observational, prospective, monocentric study, over 18 months. Serum neutrophils, lymphocytes, and thrombocytes values were collected in the preoperative period and on the third postoperative day, oxygen consumption was measured and recorded every 15 min during surgery using indirect calorimetry. We compared oxygen consumption measurements registered 30 min after induction of anesthesia (VO2a) and the first value registered after abdominal wall closure (VO2b) to perioperative variation of absolute neutrophils (VNC), lymphocytes (VLC), and platelets (VPC) count. Our results proved a significant correlation between VO2 variation and neutrophils' perioperative dynamic assessed by VNC (correlation coefficient = 0.547, p < 0.01, 95% confidence interval (CI) =0.175, 0.783). We also noticed a correlation between VPC and VO2 (correlation coefficient = -0.603, p < 0.01, 95% CI = -0.815, -0.248). No correlation could be shown between VO2 and VLC variation (p = 0.39). In conclusion, intraoperative VO2 variation measured by indirect calorimetry correlates well with perioperative neutrophils and platelets count dynamic variations and can be used as an early prognosis marker of postoperative immune response and surgical outcome in colorectal oncological surgery.

Changes in Coagulation in Cancer Patients Undergoing Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy Treatment (HIPEC)-A Systematic Review

Venous thromboembolism and postoperative bleeding are complications of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). The aim of this systematic review was to summarize current knowledge on the effect of cytoreductive surgery with HIPEC on coagulation and fibrinolysis within 10 days after surgery. Studies were identified in PubMed, Embase, and Web of Science on December 12, 2022. Data on biomarkers of coagulation and fibrinolysis measured preoperatively up to the 10th postoperative day were extracted. Among 15 included studies, 13 studies reported markers of primary hemostasis. Eleven studies found reduced platelet count following cytoreductive surgery with HIPEC and two studies reported reduced platelet function. Twelve studies reported impaired secondary hemostasis until postoperative day 10 indicated by prolonged international normalized ratio, prothrombin time, and activated partial thromboplastin time. Fibrinogen was decreased in three studies from preoperative to postoperative day 3 switching to increased levels until postoperative day 10. In accordance, three studies found reduced maximum amplitude and maximum clot firmness by thromboelastography/thromboelastometry (ROTEM/TEG) on the first postoperative day indicating impaired clot strength. Four studies demonstrated increased d-dimer, factor (F) VIII, and thrombin generation during the 10 postoperative days. Four studies investigated fibrinolysis by ROTEM/TEG and plasminogen activator inhibitor-1 (PAI-1) after cytoreductive surgery with HIPEC reporting contradictive results. In conclusion, a decrease in platelet count and subtle changes in secondary hemostasis were found following cytoreductive surgery with HIPEC. Data on the effect of cytoreductive surgery with HIPEC on fibrinolysis are sparse and this needs to be further investigated.

Successful treatment of severe passenger lymphocyte syndrome with efgartigimod synergy

INTRODUCTION

This case describes passenger lymphocyte syndrome (PLS) generating human platelet antigen 1a (HPA-1a) alloantibodies against the recipient's platelets after liver transplant. Given the rarity of PLS, especially in liver transplant with HPA-1a alloantibodies, disease course and management options are poorly described.

METHODS

The patient had cirrhosis secondary to nonalcoholic steatohepatitis complicated by hepatocellular carcinoma, encephalopathy, and severe ascites. The model for end-stage liver disease (MELD) score was 15 at presentation. The patient developed hepatic artery thrombosis after an orthotopic liver transplant and was relisted for transplant with a MELD score of 40. The patient received a hepatitis C virus antibody positive, hepatitis C virus nucleic amplification test positive donor liver on postoperative day (POD) 7 after first transplant. On POD 7 after the second transplant, the patient developed profound thrombocytopenia refractory to platelet infusion. They were found to have serum antibody to HPA-1a based upon serum platelet alloantibody testing. The donor was later found to be negative for HPA-1a by genetic testing. However, the patient's native platelets were HPA-1a positive. The patient was diagnosed with PLS.

RESULTS

The patient's treatment course included 57 units of platelets transfused, emergency splenectomy, rituximab, plasma exchange, intravenous immunoglobulin (IVIG), eltrombopag, romiplostim, and efgartigimod.

DISCUSSION

The synergistic effect of efgartigimod with eltrombopag and romiplostim most likely resolved the patient's thrombocytopenia. This case represents a novel use of efgartigimod in the treatment of passenger lymphocyte syndrome following liver transplant.

How I diagnose and treat thrombocytopenia in geriatric patients

ABSTRACT

Thrombocytopenia in older individuals is a common but diagnostically challenging condition that has variable clinical impact to those who are affected. Diagnostic approach requires evaluation of the preexisting clinical conditions, detailed review of medications, and assessment for disorders that warrant urgent treatment. In this article, we describe a systematic approach to diagnosis of thrombocytopenia and present a schematic review for management strategies. Three clinical scenarios are presented that are relevant for their prevalence and management challenges in an older adult population. The first scenario addresses primary immune thrombocytopenia (ITP) and reviews different treatment options. The second one addresses complications of thrombocytopenia in management of the myelodysplastic syndrome. The last one reviews diagnostic challenges of drug-induced ITP.

Association between postoperative nadir platelet count and postoperative cardiovascular complications following septal myectomy in patients with hypertrophic cardiomyopathy: a retrospective cohort study

BACKGROUND

Platelet count is associated with cardiovascular risk and mortality in several cardiovascular diseases, but the association of the nadir platelet counts post-septal myectomy with the cardiovascular complication risk in hypertrophic obstructive cardiomyopathy patients remains unclear.

METHODS

This retrospective cohort study reviewed all adult patients who underwent septal myectomy at a single tertiary referral center over a 5-year period. Postoperative nadir platelet count was defined as the lowest platelet count in the first 4 postoperative days or until hospital discharge. The composite outcome included cardiovascular death, myocardial infarction, heart failure, malignant arrhythmia, cardiac tamponade, and major bleeding events within 30 days postoperatively. Univariable and multivariable logistic regression and restricted cubic spline models were used to assess the association between postoperative nadir platelet count and the 30-day postoperative cardiovascular complication risk.

RESULTS

Among the 113 enrolled patients, 23 (20.4%) developed cardiovascular events within 30 days postoperatively. The incidence of postoperative cardiovascular complications was significantly higher in patients with a nadir platelet count ≤ 99 × 109/L than in those with a nadir platelet count > 99 × 109/L (33.3% vs. 7.1%, crude risk ratio: 4.67, 95% confidence interval: 1.69-12.85, P < 0.001). Multivariable logistic regression revealed that postoperative nadir platelet count was negatively associated with 30-day postoperative cardiovascular complications (adjusted odds ratio: 0.97; 95% confidence interval: 0.95-0.99; P = 0.005) and the association was linear (Pnonlinearity = 0.058) after full adjustment. The association between nadir platelet count and cardiovascular complications within 30 days post-surgery was consistent in all predefined subgroups (Pinteraction > 0.05).

CONCLUSION

The postoperative nadir platelet count was significantly associated with the 30-day post-myectomy risk of cardiovascular complications in hypertrophic obstructive cardiomyopathy patients.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov (NCT04275544).

Effect of cardiopulmonary bypass on coagulation factors II, VII and X in a primate model: an exploratory pilot study

OBJECTIVES

The use of cardiopulmonary bypass (CPB) in cardiac surgery is a major risk factor for postoperative bleeding. We hypothesized that consumptive coagulopathy and haemodilution influence the coagulation factors; therefore, we aimed to estimate the activity profiles of coagulation factors II, VII and X during CPB circulation.

METHODS

A 120-min bypass was surgically established in cynomolgus monkeys (n = 7). Activities of coagulation factors II, VII and X were measured at 6 time points during the experiment (baseline, 0, 30, 60, 120 min of bypass and 60 min after bypass). To assess the influence of consumptive coagulopathy, the values were adjusted for haemodilution using the haematocrit values. Data were expressed as mean (standard deviation).

RESULTS

Activities of coagulation factors decreased during the experiment. In particular, the activities for II, VII and X were decreased the most by 44.2% (5.0), 61.4% (4.3) and 49.0% (3.7) at 30 min following CPB initiation (P < 0.001, P < 0.001 and P < 0.001, respectively). Following adjustments for haemodilution, change magnitudes lessened but remained significant for factor VII. The adjusted concentration of factor VII was observed to decrease from the baseline to the initiation of bypass circulation.

CONCLUSIONS

In conclusion, coagulation factor II, VII and X concentrations decreased during CPB. Following adjustment for haemodilution, a decrease in concentration was observed with factor VII.

Novel Postoperative Serum Biomarkers in Atypical Meningiomas: A Multicenter Study

BACKGROUND

There has been no known serum biomarker to predict the prognosis of atypical meningioma.

OBJECTIVE

To investigate the prognostic impact of serum biomarkers in patients newly diagnosed with resected intracranial atypical meningiomas.

METHODS

This study enrolled 523 patients with atypical meningioma who underwent surgical resection between 1998 and 2018 from 5 Asian institutions. Serum laboratory data within 1 week after surgery were obtained for analysis. Optimal cutoffs were calculated for each serum marker using the maxstat package of R.

RESULTS

Of 523 patients, 19.5% underwent subtotal resection and 29.8% were treated with adjuvant radiation therapy (ART). Among the 523 patients, 454 were included in the multivariate analysis for the progression/recurrence (P/R) rate excluding patients with incomplete histopathologic or laboratory data. On multivariate analysis, tumor size >5 cm, subtotal resection, and postoperative aspartate aminotransferase/alanine transaminase (De Ritis) ratio >2 were associated with higher P/R rates, whereas ART and postoperative platelet count >137 × 10 3 /μL were associated with lower P/R rates. In the subgroup of patients treated with ART, tumor size >5 cm and postoperative neutrophil-to-lymphocyte ratio >21 were associated with higher P/R rates. By contrast, postoperative De Ritis ratio >2 remained an adverse prognosticator in patients not treated with ART.

CONCLUSION

Postoperative De Ritis ratio, platelet count, and neutrophil-to-lymphocyte ratio were revealed as a novel serum prognosticator in newly diagnosed atypical meningiomas. Additional studies are warranted to validate its clinical significance and biological background.

Interaction Between Platelet and Fibrinogen on Clot Strength in Healthy Patients

OBJECTIVE

The purpose of this study was to explore the relationship between platelet concentration (PLT) (× 10⁹/L) and clot strength measured by thromboelastography maximum amplitude (TEG-MA) in healthy volunteers without a history of coagulation abnormalities. Secondarily, the relationship between fibrinogen (mg/dL) and TEG-MA was analyzed.

DESIGN

A prospective study.

SETTING

At a university's tertiary-care center.

MEASUREMENTS AND MAIN RESULTS

Using whole blood, PLT was reduced in the first part, and hematocrit was reduced in the second part of the study by hemodilution with platelet-rich and -poor plasma. Thromboelastography (TEG 5000 Haemonetics) was performed to measure clot formation and strength. Spearman correlation coefficients regression analyses and receiver-operating characteristics (ROC) were obtained to analyze the relationships among PLT, fibrinogen, and TEG-MA. Strong correlations were found in univariate analysis between PLT and TEG-MA (r = 0.88; p < 0.0001) and between Fibrinogen and TEG-MA (r = 0.70; p = 0.003). A biphasic relationship between PLT and TEG-MA was linear below a PLT 90 × 10⁹/L, followed by a plateau above 100 × 10⁹/L (p = 0.001). A linear relationship between fibrinogen (190-474 mg/dL) and TEG-MA (53-76 mm) was found (p = 0.0007). The ROC analysis found that PLT = 60 × 10⁹/L was associated with a TEG-MA of 53.0 mm. The product of PLT and fibrinogen concentrations was more strongly correlated (r = 0.91) to TEG-MA than either PLT (r = 0.86) or fibrinogen (r = 0.71) alone. A ROC analysis revealed that a TEG-MA of 55 mm was associated with a PLT × fibrinogen of 16,720.

CONCLUSION

In healthy patients, a PLT of 60 × 10⁹/L was associated with normal clot strength (TEG-MA ≥53 mm), and there was little change in clot strength with PLT >90 × 10⁹/L. Although prior analyses described the contributions of platelets and fibrinogen toward clot strength, they are presented and discussed independently. The data above described clot strength as an interaction among them. Future analyses and clinical care should evaluate and recognize the interplay.

Association Between Thromboelastometry Identified Hypercoagulability and Thromboembolic Complications After Arthroplasty: A Prospective Observational Study in Patients With Obesity

The prothrombotic state of obesity can increase the risk of thromboembolism. We aimed to investigate if there was an association between baseline hypercoagulable rotational thromboelastometry (ROTEM) profile and thromboembolic complications in arthroplasty patients with obesity. Patients with a body mass index ≥ 25 kg/m2 and/or waist circumference ≥94 cm (M) and 80 cm (F) undergoing hip and knee arthroplasty had pre- and postoperative ROTEM. ROTEM values were compared by outcome status using an independent sample equal-variance t-test. Of the 303 total participants, hypercoagulability defined as extrinsically activated thromboelastometry maximum clot firmness G score ≥ 11 K dyne/cm2, was observed in 90 (30%) of the 300 participants with preoperative ROTEM assays. Clinically significant thromboembolic complications occurred in 5 (1.7%) study participants before discharge and in 10 (3.3%) by 90 days. These included 6 with pulmonary emboli, 3 with deep venous thrombus, and 1 with myocardial infarction. We found no evidence for an association between baseline hypercoagulability and incident thromboembolic events, analysis limited by the number of events. Postoperative decrease in platelets and an increase in fibrinogen were observed. ROTEM parameter changes differed across obesity categories.

Postsurgical Thrombotic Microangiopathy and Deregulated Complement

Postsurgical thrombotic microangiopathy (TMA) is a complication associated with significant morbidity and mortality. Still, the pathophysiological underlying mechanism of postsurgical TMA, a diagnosis often overlooked in postoperative patients with acute kidney injury and thrombocytopenia, is largely unknown. Here, we report the case of a 56-year-old male that developed anuric acute kidney injury, Coombs-negative hemolysis, and thrombocytopenia after surgical aortic arch replacement. Massive ex vivo complement activation on the endothelium, a rare complement gene variant in C2, at-risk haplotype MCPggaac, and excellent response to therapeutic complement inhibition, points to the pivotal role of complement in the pathophysiology of disease. Moreover, the importance of a multidisciplinary team approach in (postsurgical) thrombocytopenia is emphasized.

Heparin-induced Thrombocytopenia: Perioperative Diagnosis and Management

Heparin-induced thrombocytopenia is a severe prothrombotic disease. Timely diagnosis and treatment are essential. Application of diagnostic algorithms based on validated clinical scoring tools and rapid, specific laboratory assays may improve outcomes.

Accuracy of a modified 4Ts score in predicting heparin-induced thrombocytopenia in critically ill patients: A pilot study

PURPOSE

Thrombocytopenia is common among critically ill patients and heparin-induced thrombocytopenia (HIT) is often on the differential. Professional guidelines recommend calculating a pre-test probability score before performing HIT testing. The 4Ts score is widely utilized but accuracy has been questioned in critically ill patients. The HIT Expert Probability (HEP) score is available, but complexity limits use. Our objective was to compare a modified intensive care unit (ICU)-4Ts score to available scoring tools.

MATERIALS AND METHODS

This was a single-center retrospective pilot study. Adult ICU patients that were tested for HIT and had a documented 4Ts score were included. A blinded investigator retrospectively calculated the HEP and ICU-4Ts score. Receiver operating characteristics (ROC) area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were compared.

RESULTS

In 194 included patients, ROC AUC was significantly higher for the ICU-4Ts compared to the 4Ts score (0.80 versus 0.66, respectively; p = 0.044). The ICU-4Ts score had the highest specificity, PPV, and NPV. The sensitivity was similar between the HEP and ICU-4Ts score.

CONCLUSIONS

The ICU-4Ts score better predicted the diagnosis of HIT compared to the 4Ts score. Prospective validation studies are needed to confirm these results.

Meropenem-induced thrombocytopenia: a paediatric case

Meropenem is a broad-spectrum carbapenem widely used to treat both Gram-positive and negative bacterial infections, including extended-spectrum beta-lactamase-producing microbes. We describe the occurrence of thrombocytopenia and hypersensitivity in a boy receiving intravenous meropenem for intra-abdominal sepsis secondary to perforated appendicitis. The patient developed a pruritic maculopapular rash with occasional petechiae, associated with severe thrombocytopenia, after 7 days of meropenem administration. Investigations for other causes of thrombocytopenia, including possible line sepsis, were unfruitful, and the thrombocytopenia did not resolve until cessation of meropenem. Drug-induced reactions should be considered in children receiving meropenem who present with a rash and thrombocytopenia.

Thrombocytopenia secondary to acute appendicitis: A case report

Thrombocytopenia is a rare but possible complication of appendicitis and, if severe, might be a contraindication to appendectomy.

Comparison of Clinical Scoring Tools to Predict Heparin-Induced Thrombocytopenia in Cardiac Surgery

The 4Ts and HIT-Expert Probability (HEP) scoring tools for heparin-induced thrombocytopenia (HIT) have not been validated in cardiac surgery patients, and the reported sensitivity and specificity of the Post-Cardiopulmonary Bypass (CPB) scoring tool vary widely in the 2 available analyses. It remains unclear which of the available scoring tools most accurately predicts HIT in this population. Forty-nine HIT-positive patients who underwent on-pump cardiac surgery within a 6-year period were loosely matched to 98 HIT-negative patients in a 1:2 case-control design. The 4Ts, HEP, and CPB scores were calculated for each patient. Sensitivity and specificity of each tool were calculated using standard cut-offs. The Youden method was utilized to determine optimal cut-offs within receiver operating characteristic (ROC) curves of each score, after which sensitivities and specificities were recalculated. Using standard cut-offs, the sensitivities for the CPB, HEP, and 4Ts scores were 100%, 93.9%, and 69.4%, respectively. Specificities were 51%, 49%, and 71.4%, respectively. The AUC of the scoring tool ROC curves were 0.961 for the CPB score, 0.773 for the HEP score, and 0.805 for the 4Ts score. Using the Youden method-derived optimal cut-off of  ≥3 points on the CPB score, sensitivity remained 100% with improved specificity to 88.9%. The CPB score is the preferred HIT clinical scoring tool in adult cardiac surgery patients, whereas the 4Ts score performed less effectively. A cut-off of ≥ 3 points on the CPB score could increase specificity while preserving high sensitivity, which should be validated in a prospective evaluation.

Factors predisposing to thrombosis after major joint arthroplasty

BACKGROUND

Total joint arthroplasty is one of the most common options for end stage osteoarthritis of major joints. However, we must take into account that thrombosis after hip/knee arthroplasty may be related to mutations in genes encoding for blood coagulation factors and immune reactions to anticoagulants [heparin-induced thrombocytopenia (HIT)/thrombosis]. Identifying and characterizing genetic risk should help to develop diagnostic strategies or modify anticoagulant options in the search for etiological mechanisms that cause thrombophilia following major orthopedic surgery.

AIM

To evaluate the impact of patients’ coagulation profiles and to study specific pharmacologic factors in the development of post-arthroplasty thrombosis.

METHODS

In 212 (51 male and 161 female) patients that underwent primary total hip arthroplasty (100) or total knee arthroplasty (112) due to osteoarthritis during a period of 1 year, platelet counts and anti-platelet factor 4 (PF4)/heparin antibodies were evaluated pre/postoperatively, and antithrombin III, methylenetetrahydrofolate reductase, factor V and prothrombin gene mutations were evaluated preoperatively. In a minimum follow-up of 3 years, 196 patients receiving either low-molecular-weight heparins (173) or fondaparinux (23) were monitored for the development of thrombocytopenia, anti-PF4/heparin antibodies, HIT, and thrombosis.

RESULTS

Of 196 patients, 32 developed thrombocytopenia (nonsignificant correlation between anticoagulant type and thrombocytopenia, P = 0134.) and 18 developed anti-PF4/heparin antibodies (12/173 for low-molecular-weight heparins and 6/23 for fondaparinux; significant correlation between anticoagulant type and appearance of antibodies, P = 0.005). Odds of antibody emergence: 8.2% greater in patients receiving fondaparinux than low-molecular-weight heparins. Gene mutations in factor II or V (two heterozygotes for both factor V and II) were identified in 15 of 196 patients. Abnormal low protein C and/or S levels were found in 3 of 196 (1.5%) patients, while all patients had normal levels of von Willebrand factor, lupus anticoagulant, and antithrombin III. Four patients developed HIT (insignificant correlation between thrombocytopenia and antibodies) and five developed thrombosis (two had positive antibodies and two were heterozygotes for both factor II & V mutations). Thrombosis was not significantly correlated to platelet counts or HIT. The correlation of thrombosis to antibodies, factor II, factor V was P = 0.076, P = 0.043, P = 0.013, respectively.

CONCLUSION

Screening of coagulation profile, instead of platelet monitoring, is probably the safest way to minimize the risk of post-arthroplasty thrombosis. In addition, fondaparinux can lead to the formation of anti-PF4/heparin antibodies or HIT.

Heparin Induced Thrombocytopenia for the Perioperative and Critical Care Clinician

Purpose of Review

This review will illustrate the importance of heparin-induced thrombocytopenia in the intraoperative and critical care settings.

Recent Findings

Heparin-induced thrombocytopenia (HIT) occurs more frequently in surgical patients compared with medical patients due to the inflammatory release of platelet factor 4 and perioperative heparin exposure. Recognition of this disease requires a high index of suspicion. Diagnostic tools and therapeutic strategies have been expanded and refined in recent years.

Summary

HIT is a condition where antibodies against the heparin/platelet factor 4 complex interact with platelet receptors to promote platelet activation, aggregation, and thrombus formation. Our review will focus on intraoperative and postoperative considerations related to HIT to help the clinician better manage this rare but often devastating hypercoagulable disease process.