Venous Thromboembolism Prophylaxis in Low Body Weight Critically Ill Patients.

OBJECTIVE: To compare bleeding and thromboembolic events in low body weight patients receiving reduced-dose venous thromboembolism (VTE) prophylaxis versus standard-dose VTE prophylaxis. DESIGN: Multicenter, retrospective, cohort study. SETTING: Five Ascension Health Hospitals. PATIENTS: Adult, critically ill, low body weight (≤50 kg) patients who received either reduced-dose VTE prophylaxis (n = 140) or standard-dose VTE prophylaxis (n = 279) for at least 48 h. INTERVENTION: Reduced-dose prophylaxis (enoxaparin 30 mg daily or heparin 5000 units every 12 h subcutaneously) or standard-dose prophylaxis (enoxaparin 40 mg daily, enoxaparin 30 mg every 12 h, or heparin 5000 units every 8 h subcutaneously). MEASUREMENTS AND MAIN RESULTS: A total of 419 patients were included with a mean weight of 45.1 ± 4.2 kg in the standard-dose group and 44.0 ± 5.1 kg in the reduced-dose prophylaxis group (P = .02). The primary endpoint, composite bleeding, was significantly lower in patients receiving reduced-dose prophylaxis (5% vs 12.5%, P = .02). After adjusting for confounding factors, results remained consistent demonstrating reduced composite bleeding with reduced-dose prophylaxis (odds ratio: 0.36, 95% confidence interval: 0.14-0.96). Major bleeding events occurred in 3.6% of reduced-dose patients compared with 8.6% in standard-dose patients (P = .056). Clinically relevant nonmajor bleeding (5.4% vs 2.9%, P = .24) and VTE (2.2% vs 0%, P = .08) events were similar between groups. CONCLUSIONS: A reduced-dose VTE prophylaxis strategy in low body weight, critically ill patients was associated with a lower risk of composite bleeding and similar rate of thromboembolism.

Incidence of Symptomatic Venous Thromboembolisms in Stroke Patients.

Venous thromboembolism (VTE) is a common but preventable complication observed in critically ill patients. Deep vein thrombosis (DVT) is the most common type of VTE, with clinical significance based on location and symptoms. There is an increased incidence of DVT and pulmonary embolism (PE) in ischemic stroke patients using unfractionated heparin (UFH) for VTE prophylaxis compared with those using enoxaparin. However, UFH is still used in some patients due to its perceived safety, despite conflicting literature suggesting that enoxaparin may have a protective effect. The current study aimed to determine the incidence of VTEs in patients with acute ischemic strokes on UFH versus enoxaparin for VTE prophylaxis, subclassifying the VTEs depending on their location and symptoms. It also aimed to examine the safety profile of both drugs. A total of 909 patients admitted to the Neuro-ICU with the diagnosis of acute ischemic stroke were identified, and 634 patients were enrolled in the study-170 in the enoxaparin group and 464 in the UFH group-after applying the exclusion criteria. Nineteen patients in the UFH group (4.1%) and 3 patients in the enoxaparin group (1.8%) had a VTE. The incidence of DVT in the UFH group was 12 (2.6%), all of which were symptomatic, compared with 3 (1.8%) in the enoxaparin group, wherein one case was symptomatic. Nine patients (1.9%) in the UFH group developed a PE during the study period, and all of them were symptomatic. No patients in the enoxaparin group developed PE. No statistically significant difference was found between both groups. However, 18 patients in the UFH group (3.9%) experienced intracranial hemorrhage compared with none in the enoxaparin group, and this difference was statistically significant. Enoxaparin was found to be as effective as and potentially safer than UFH when used for VTE prophylaxis in stroke patients.

Is a minimum duration of 5 days of unfractionated heparin infusion necessary before transition to oral anticoagulation in cerebral venous thrombosis? a retrospective chart review.

In managing cerebral venous sinus thrombosis (CVT), the standard approach has been administering parenteral anticoagulation for at least five days, despite limited supporting evidence. This study aimed to determine the optimal duration of parenteral anticoagulation for CVT patients and its potential impact on their functional outcomes upon discharge. This retrospective observational cohort study was conducted across multiple healthcare centers and included adult CVT patients who received varying durations of parenteral anticoagulation: less than 5 days (n = 25) or 5 days or more (n = 16). The primary focus was on the duration of acute anticoagulation treatment, with secondary endpoints including hospital stay length and functional outcomes. The study found that a shorter duration of anticoagulation treatment (< 5 days) was linked to more favorable outcomes, as measured by the modified Rankin Scale (mRS) (68% vs. 25%, RR = 0.37, CI 0.15-0.90, p = 0.007). However, regression analysis showed non statistically significant associations for all variables except gender. Female patients were significantly more likely to receive a shorter duration of anticoagulation (Odds Ratio: 2.6, 95% CI: 2.2-3.1, P-Value: <0.001). These findings suggest a potential connection between shorter anticoagulation duration (< 5 days) and improved CVT patient outcomes, as indicated by their mRS scores at discharge. The observed relationship between female gender and shorter anticoagulation duration warrants further exploration. Nevertheless, caution is necessary when interpreting these findings due to the small sample size and specific patient characteristics. Further research in a larger and more diverse cohort is essential to validate these results and understand their implications fully.

Impact of augmented renal clearance on anticoagulant therapy in critically ill patients with coronavirus disease 2019: A retrospective cohort study.

INTRODUCTION: This study aimed to determine the impact of augmented renal clearance (ARC) on anticoagulation therapy in critically ill patients with coronavirus disease 2019 (COVID-19). METHODS: This retrospective cohort study included adult patients with severe COVID-19 with ARC who had been treated at our hospital between 2020 and 2021. We measured the estimated glomerular filtration rate calculated by the Chronic Kidney Disease Epidemiology Collaboration formula (eGFRCKD-EPI) every morning, and ARC condition was defined as eGFRCKD-EPI ≥ 130 mL/min/1.73 m2. Multivariate regression analysis with Huber-White sandwich estimator was performed to examine the association of unfractionated heparin (UH) dosage between blood test timings with activated partial thromboplastin time (APTT) compared with and without ARC. RESULTS: We identified 38 enrolled patients: seven and 31 in the ARC and non-ARC groups, respectively. In the ARC coexisting condition, a higher dose of UH, which corresponded to the total dose in 24 h from the previous day, was required to achieve the same APTT prolongation, with a significant difference (p < 0.001). CONCLUSIONS: Our study suggests that careful monitoring and consideration of higher UH doses in critically ill patients with COVID-19 is necessary because anticoagulation failure can occur during ARC.

Contributing factors to heparin resistance during cardiopulmonary bypass.

Since the risk factors for heparin resistance (HR) before cardiopulmonary bypass (CPB) have not been fully clarified, this study investigated the contributing factors for HR after the initial unfractionated heparin (UFH) dose of 500 IU/kg. We retrospectively analyzed the data of 371 patients who underwent CPB surgery, with the initial UFH dose of 500 IU/kg, between May 2017 and December 2021. We defined HR as the failure to achieve activated clotting time (ACT) of > 480 s after the initial UFH dose of 500 IU/kg. HR was observed in 36 patients (9.7%) (HR group), while HR was not observed in 335 patients (control group). The HR group included significantly more patients with preoperative use of UFH, with significantly higher white blood cell counts, fibrinogen, fibrinogen degradation products, D-dimer, and C-reactive protein, and lower hemoglobin and albumin. The multivariable logistic regression analysis identified albumin (OR: 3.09, 95% CI 1.3504-7.0845, p = 0.0075) and fibrinogen (OR: 0.99, 95% CI 0.9869-0.9963, p = 0.0003) as independent predictors for HR. Using the Youden index, the cutoffs of albumin and fibrinogen were calculated as 3.8 g/dL and 303 mg/dL, respectively. The receiver operating characteristic curves showed the predictive performance of albumin (area under the curve (AUC): 0.78, sensitivity: 65%, specificity: 81%) and fibrinogen (AUC: 0.77, sensitivity: 56%, specificity: 88%). The incidence of HR after the initial UFH dose of 500 IU/kg was 9.7%. The preoperative albumin < 3.8 g/dL and fibrinogen > 303 mg/dL were independent predictors for HR.

One-Year Safety and Effectiveness of Bivalirudin versus Heparin in Patients Undergoing Elective Percutaneous Coronary Intervention.

Background: Bivalirudin reduces ischemic and hemorrhagic events in patients undergoing primary percutaneous coronary intervention (PCI), but the safety and efficacy for such individuals are unclear. Our aim was to evaluate the long-term safety and efficacy of bivalirudin in patients undergoing elective PCI. Methods: We examined 957 patients with bivalirudin anticoagulation and 1713 patients with unfractionated heparin (UFH) anticoagulation with and without glycoprotein IIb/IIIa inhibitors (GPI). The primary endpoint was net adverse clinical events (NACE), a composite of death, myocardial infarction, revascularization, stent thrombosis, stroke, and bleeding. The secondary endpoints were bleeding and major adverse cardiovascular and cerebrovascular events (MACCE). Results: In one year of follow-up, 307 (11.5%) NACEs, 72 (2.7%) bleedings, and 249 (9.3%) MACCEs occurred. Statistically, patients with bivalirudin anticoagulation had less NACE [hazard ratio (HR): 0.75, 95% confidence interval (CI): 0.58-0.96, p = 0.021] and bleeding (HR: 0.58, 95% CI: 0.34-0.99, p = 0.045) but not less MACCE, than did those with UFH anticoagulation. Furthermore, the risk of bleeding in the bivalirudin group was lower than in the UFH with GPI group (p = 0.001) but not lower than in the group of UFH without GPI (p = 0.197). Conclusions: In patients who undergo elective PCI, the use of bivalirudin significantly decreased the risk of NACE and bleeding without increasing the risk of MACCE; the reduction of bleeding risk with bivalirudin was mainly attributed to the presence of GPIs in the UFH group.

Inhaled nebulised unfractionated heparin (UFH) for the treatment of hospitalised patients with COVID-19: A randomised controlled pilot study.

There is a strong scientific rationale to use nebulised unfractionated heparin (UFH) in treating patients with COVID-19. This pilot study investigated whether nebulised UFH was safe and had any impact on mortality, length of hospitalisation and clinical progression, in the treatment of hospitalised patients with COVID-19. This parallel group, open label, randomised trial included adult patients with confirmed SARS-CoV-2 infection admitted to two hospitals in Brazil. One hundred patients were planned to be randomised to either "standard of care" (SOC) or SOC plus nebulized UFH. The trial was stopped after randomisation of 75 patients due to falling COVID-19 hospitalisation rates. Significance tests were 1-sided test (10% significance level). The key analysis populations were intention to treat (ITT) and modified ITT (mITT) which excluded (from both arms) subjects admitted to ITU or who died within 24 h of randomisation. In the ITT population (n = 75), mortality was numerically lower for nebulised UFH (6 out of 38 patients; 15.8%) versus SOC (10 out of 37 patients; 27.0%), but not statistically significant; odds ratio (OR) 0.51, p = 0.24. However, in the mITT population, nebulised UFH reduced mortality (OR 0.2, p = 0.035). Length of hospital stay was similar between groups, but at day 29, there was a greater improvement in ordinal score following treatment with UFH in the ITT and mITT populations (p = 0.076 and p = 0.012 respectively), while mechanical ventilation rates were lower with UFH in the mITT population (OR 0.31; p = 0.08). Nebulised UFH did not cause any significant adverse events. In conclusion, nebulised UFH added to SOC in hospitalised patients with COVID-19 was well tolerated and showed clinical benefit, particularly in patients who received at least 6 doses of heparin. This trial was funded by The J.R. Moulton Charity Trust and registered under REBEC RBR-8r9hy8f (UTN code: U1111-1263-3136).

Unfractionated Heparin Protects Microcirculation in Endotoxemic Rats by Antagonizing Histones.

INTRODUCTION: Levels of extracellular histones are highly increased in sepsis and may facilitate microcirculatory dysfunction. Unfractionated heparin (UFH) binds histones and neutralizes their cytotoxicity. We investigated the effect of UFH on microcirculatory dysfunction by interacting with extracellular histones in endotoxemic rats. METHODS: Twenty-four Wistar rats were randomly divided into three groups: control, lipopolysaccharide (LPS) group, and LPS + UFH group. In the LPS and LPS + UFH groups, 10 mg/kg LPS was injected to induce endotoxemia, and 100 IU/kg/h UFH was administered intravenously in the LPS + UFH group. The rats underwent midline laparotomy, and then intestinal microcirculation was evaluated using an incident dark field microscope. Circulating histones and microstructures of the rat intestinal microvascular endothelium were also detected. Additionally, the antagonistic effect of UFH on histone-induced cytotoxicity was investigated in human intestinal microvascular endothelial cells. RESULTS: UFH protected the microcirculation of the intestinal serosa and mucosa in endotoxemic rats, as evidenced by increased total vessel density, perfused vessel density, and proportion of perfused vessels of both the serosa and mucosa, and increased microcirculatory flow index of the mucosa in the LPS + UFH group. UFH treatment decreased the levels of circulating histones and alleviated intestinal microvascular endothelial injuries in endotoxemic rats. Furthermore, UFH inhibited histone cytotoxicity in vitro. CONCLUSIONS: UFH attenuated microcirculatory dysfunction in endotoxemic rats by antagonizing extracellular histones, thereby providing a potential therapeutic strategy for sepsis.

Meta-analysis of the effectiveness of heparin in suppressing physiological myocardial FDG uptake in PET/CT.

BACKGROUND: The present meta-analysis aims to investigate the effectiveness of heparin administration in suppressing physiological myocardial 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET)/computed tomography (CT), as its role in this regard has not been well investigated. METHODS: PRISMA guidelines were used to interrogate the PubMed, Embase, Cochrane library, Web of Knowledge, and www.clinicaltrail.gov databases from the earliest records to March 2023. The final analysis included five randomized controlled trials (RCTs). Meta-analysis was conducted to compare the effectiveness of unfractionated heparin (UFH) administration versus non-UFH administration, and subgroup analysis based on fixed and variable fasting durations was conducted. Effect sizes were pooled using a random-effects model, and the pooled odds ratios (ORs) were calculated. RESULTS: Five eligible RCTs with a total of 910 patients (550 with heparin, 360 without heparin) were included. The forest plot analysis initially indicated no significant difference in the suppression of myocardial FDG uptake between the UFH and non-UFH groups (OR 2.279, 95% CI 0.593 to 8.755, p = 0.23), with a high degree of statistical heterogeneity (I2 = 91.16%). Further subgroup analysis showed that the fixed fasting duration group with UFH administration had statistically significant suppression of myocardial FDG uptake (OR 4.452, 95% CI 1.221 to 16.233, p = 0.024), while the varying fasting duration group did not show a significant effect. CONCLUSIONS: According to the findings of our meta-analysis, we suggest that intravenous administration of UFH can be considered as a supplementary approach to suppress myocardial FDG uptake.

Assessment of bleeding risk in low-weight patients receiving prophylactic subcutaneous unfractionated heparin.

BACKGROUND: Underweight patients may be at an increased risk of bleeding while receiving venous thromboembolism (VTE) prophylaxis. Additional evidence is needed to identify patient-specific factors associated with bleeding. The objective of the study was to describe the incidence and identify risk factors associated with bleeding in low-weight (⩽ 60 kg) adult patients receiving subcutaneous unfractionated heparin (SQH) for VTE prophylaxis. METHODS: This was a single-center, retrospective, nested case-control study of low-weight patients receiving SQH for VTE prophylaxis for ⩾ 48 hours. Cases, patients with clinically relevant bleeding while receiving SQH, and controls, patients without a bleeding event, were matched in a 1:3 ratio for age, sex, primary service (surgical or medical), and time at risk of bleeding on SQH to determine factors associated with bleeding. RESULTS: A total of 3761 patients met the inclusion criteria, of which 38 cases of clinically relevant bleeding were identified. The bleeding incidence was 1% at hospital day 6 and 2.8% at hospital day 14. Most patients in this study (69%) received SQH 5000 units three times daily. ICU admission at SQH start was associated with bleeding, OR 2.97 (95% CI 1.21-7.29). CONCLUSION: Bleeding in low-weight patients on prophylactic SQH was uncommon. Patients admitted to the ICU at time of SQH start may be at a higher risk of bleeding. Further studies are needed to detect additional risk factors associated with bleeding and investigate the effects of reduced dosing in this population.

Enoxaparin may be associated with lower rates of mortality than unfractionated heparin in neurocritical and surgical patients.

Unfractionated heparin (UFH) and low molecular weight heparin (LMWH) are often administered to prevent venous thromboembolism (VTE) in critically ill patients. However, the preferred prophylactic agent (UFH or LMWH) is not known. We compared the all-cause mortality rate in patients receiving UFH to LMWH for VTE prophylaxis. We conducted a retrospective propensity score adjusted analysis of patients admitted to neuro-critical, surgical, or medical intensive care units. Patients were included if they were screened with venous duplex ultrasonography or computed tomography angiography for detection of VTE. The primary outcome was all-cause mortality. Secondary outcomes included the prevalence of VTE, deep vein thrombosis (DVT), pulmonary embolism (PE), and hospital length of stay (LOS). Initially 2228 patients in the cohort were included for analysis, 1836 (82%) patients received UFH, and 392 (18%) patients received enoxaparin. After propensity score matching, a well-balanced cohort of 618 patients remained in the study (309 patients receiving UFH; 309 patients receiving enoxaparin). The use of UFH for VTE prophylaxis in ICU patients was associated with similar rates of all-cause mortality compared with enoxaparin [RR 0.73; 95% CI 0.43-1.24, p = 0.310]. There were no differences in the prevalence of DVT, prevalence of PE or hospital LOS between the two groups, DVT [RR 0.93; 95% CI 0.56-1.53, p = 0.889], PE [RR 1.50; 95% CI 0.78-2.90, p = 0.296] and LOS [9 ± 9 days vs 9 ± 8; p = 0.857]. A trend toward mortality benefit was observed in NICU [RR 0.37; 95% CI 0.13-1.07, p = 0.062] and surgical patients [RR 0.43; 95% CI 0.17-1.02, p = 0.075] favoring the enoxaparin group. The use of UFH for VTE prophylaxis in ICU patients was associated with similar rates of VTE, all-cause mortality and LOS compared to enoxaparin. In subgroup analysis, neuro-critical and surgical patients who received UFH had a higher rate of mortality than those who received enoxaparin.

Unfractionated heparin versus nafamostat mesylate for anticoagulation during continuous kidney replacement therapy: an observational study.

BACKGROUND: Unfractionated heparin sodium and nafamostat mesylate have long been used as anticoagulants in continuous kidney replacement therapy (CKRT) where citrate is unavailable. This study aimed to determine whether heparin or nafamostat mesylate used during CKRT was associated with a longer filter life. METHODS: In this single-centre observational study, we included adult patients who required CKRT and used heparin or nafamostat mesylate for their first CKRT in the intensive care unit from September 1, 2013, to December 31, 2020. The primary outcome was filter life (from the start to the end of using the first filter). We used propensity score matching to adjust for the imbalance in patients' characteristics and laboratory data at the start of CKRT and compared the outcomes between the two groups. We also performed restricted mean survival time analysis to compare the filter survival times. RESULTS: We included 286 patients, 157 patients on heparin and 129 patients on nafamostat mesylate. After propensity score matching, the mean filter life with heparin was 1.58 days (N = 91, Standard deviation [SD], 1.52) and with nafamostat mesylate was 1.06 days (N = 91, SD, 0.94, p = 0.006). Multivariable regression analysis adjusted for confounding factors supported that heparin was associated with a longer filter life compared with nafamostat mesylate (regression coefficient, days, 0.52 [95% CI, 0.15, 0.89]). The between group difference of the restricted mean filter survival time in the matched cohort was 0.29 (95% CI, 0.07-0.50, p = 0.008). CONCLUSION: Compared to nafamostat mesylate, heparin was associated with one-third to one-half a day longer filter life. TRIAL REGISTRATION: Not applicable.

Perioperative management in chronically anticoagulated children undergoing tonsillectomy.

BACKGROUND: When undergoing tonsillectomy, patients at high risk of thrombosis who require chronic anticoagulation therapy pose a special challenge as bleeding may occur up to 2 weeks after surgery. Because of a lack of evidence-based data, there is no consensus on the best management for such patients. The objective of our study was to review perioperative anticoagulation bridging strategies in children undergoing tonsillectomy. METHODS: The study group were a retrospective series of patients on chronic anticoagulation therapy at high risk of a thromboembolic event, who underwent tonsillectomy from 2010 to 2021. Patients whose anticoagulation treatment was discontinued because of a low risk of thromboembolic events were excluded. RESULTS: Four patients met the inclusion criteria (age range, 1.5-16.1 years). All patients were admitted prior to surgery for bridging therapy with intravenous unfractionated heparin (UFH), drip-titrated to a therapeutic dose until 4-6 h prior to surgery. The estimated blood loss during surgery was minimal in all surgeries. Unfractionated heparin was readministered according to the hospital protocol on the night of surgery and titrated to a therapeutic dose. Warfarin was restarted within 2 days postsurgery for all patients. High-risk patients were kept in hospital until postoperative day 6-8 because of concern for delayed bleeding. One patient was noticed to have blood-tinged sputum requiring no intervention; none of the patients developed early or delayed hematemesis. CONCLUSIONS: Our data show that bridging therapy with UFH has been successful in chronically anticoagulated patients undergoing tonsillectomy. These patients require multidisciplinary care for the management of their pre- and postoperative course.

The usage and outcomes of dextran in the treatment of acute deep venous thrombosis.

OBJECTIVES: In this study, we retrospectively compared the outcomes of patients with acute deep vein thrombosis treated with dextran 40 infusion and unfractionated heparin with those of patients treated with unfractionated heparin alone. METHODS: We evaluated 104 patients with the diagnosis of acute deep vein thrombosis. The pain complaints of the patients at the time of admission and the pain complaints in the calf with dorsiflexion of the foot were evaluated with the visual analogue pain scale, and the calf diameter of affected limbs was measured. Fifty five patients had dextran 40 infusion and unfractionated heparin treatment concomitantly (Group HD), while 49 patients had unfractionated heparin treatment (Group H). Heparin dose was adjusted to obtain 1.5- to 2.5-fold of normal activated partial thromboplastin time in both groups. Oral anticoagulant, warfarin sodium, was administered in the first day and resumed. Unfractionated heparin infusion therapy was resumed until international normalized ratio values of 2-2.5 were obtained. Dextran 40 infusion therapy was administered for 3 days. Calf diameters, current pain, and calf pain at foot dorsiflexion were recorded at 48 h and 72 h. 65 patients were distal, and 39 patients were proximal and popliteal acute DVT. None of the patients had phlegmasia. All were acute DVT. RESULTS: At 48 and 72 h of therapy, it was determined that the decrease of the calf diameter and the pain were more significant both at 48th and 72nd hours in the Group HD. The calf circumference change, especially at 72 h, was 2.58 ± 0.39 cm in the group receiving heparin + dextran, while it was 1.76 ± 0.56 cm in the group receiving only heparin. (p = 0.000). While there were only 1.24 ± 1.02 people in the group that received dextran at 72 h, leg pain persisted in 3.35 ± 1.11 people in the other group. (p = 0.000). Evaluation was made only with calf vein diameter measurement. When patients with Homan's sign were evaluated for their calf pain at foot dorsiflexion; both groups had decreased pain at 48th and 72nd hours. CONCLUSION: In this study, we observed that the use of dextran 40 infusion therapy concomitantly with unfractionated heparin accelerates recovery substantially and decreases patient complaints significantly in early stages. In particular, reduction in leg pain and calf circumference reduction were more adequate in the dextran group. The early decrease in the calf circumference will have clinical consequences such as less heparin intake, earlier return to normal life, and a decrease in the total cost of treatment. Since the antithrombotic and anticoagulant effects of dextran are well known, we think that its use in this treatment as well as venous thromboembolism prophylaxis should be discussed.

Role of Nebulized Heparin in Clinical Outcome of COVID-19 Patients with Respiratory Symptoms: A Systematic Review.

Coronavirus disease-2019 (COVID-19) is an extremely contagious illness caused by the SARS-CoV-2 virus and has been declared a pandemic by the World Health Organization (WHO). There are currently no particular treatments, however, nebulized heparin has been offered as a viable therapy. The purpose of this systematic review is to assess the efficacy of nebulized heparin in COVID-19 patients with respiratory symptoms. Methods: Relevant studies were identified through a systematic search of the PubMed, Medline, Embase, Cochrane Library and Web of Science, and Scopus databases. The search terms included "nebulized heparin," "COVID-19," and "SARS-CoV-2." Studies that evaluated the use of nebulized heparin in COVID-19 patients with respiratory symptoms were included. The rest of the studies along with those that were not published in English were excluded. The systematic review was registered under PROSPERO-CRD42023413927. Observations: Five studies have been included in this systematic review. Case reports, case series, observational studies, and randomized controlled trial (RCT) comprised the studies. The patient sample sizes ranged from 2 to 98. The studies assessed the efficacy of nebulized heparin in COVID-19 patients with variable disease severity. The evaluated outcomes included mortality, hospital stay duration, oxygen requirements, and laboratory parameters. Conclusion: Based on the clinical studies included in this systematic review, nebulized heparin may be useful in the management of COVID-19. Oxygen saturation was greater, inflammatory indicators were lower, and hospital stays were shorter in these patients. However, the studies had limitations, including inconsistent sample sizes, varying dosages of nebulized heparin, and no control groups. Nebulized heparin in patients with COVID-19 needs to be studied further to determine its safety and effectiveness. How to cite this article: Gupta B, Ahluwalia P, Gupta N, Gupta A. Role of Nebulized Heparin in Clinical Outcome of COVID-19 Patients with Respiratory Symptoms: A Systematic Review. Indian J Crit Care Med 2023;27(8):572-579.

Emicizumab does not interfere with the activated clotting time.

INTRODUCTION: The activated clotting time (ACT) is a useful marker of unfractionated heparin (UFH) activity during cardiopulmonary bypass (CPB) or cardiac catheterization. Emicizumab, recently approved for bleeding prevention in haemophilia A patients, acts like FVIII but does not need prior activation; it therefore shortens coagulation times in assays using intrinsic pathway activators and so is expected to shorten the ACT. AIM: To evaluated emicizumab's impact on heparin-induced ACT (Hemochron®) prolongation. METHODS: We measured the high-range (HR) ACT in citrated blood samples from healthy donors (HDs) (n = 9), CPB patients (n = 3) and emicizumab-treated patients (n = 5) after spiking with UFH and/or emicizumab. The low range (LR) ACT was also measured in spiked-samples from HDs and emicizumab-treated patients. RESULTS: In HDs, the median [interquartile range] baseline HR-ACTs were similar with and without emicizumab (129 [123-138] and 136 [115-141] s for 50 µg/ml, respectively); whatever the concentration of emicizumab (10 to 50 µg/ml), increasing the UFH concentration (1-5 UI/ml) prolonged the HR-ACT. In blood from patients undergoing CPB, the HR-ACT prolongation observed during this procedure was not masked by emicizumab at any concentration. Likewise, the addition of increasing concentrations of UFH to blood from emicizumab-treated patients induced a concentration-dependent prolongation of HR-ACT. Baseline LR-ACT were prolonged in emicizumab-treated patients but as for HR-ACT, emicizumab does not prevent heparin-induced prolongation of LR-ACT. CONCLUSION: Emicizumab does not interfere with UFH-induced ACT prolongation. The hemochron® ACT can be used to monitor UFH in patients receiving emicizumab during CPB or cardiac catheterization.

Effectiveness and safety of bivalirudin in elderly patients with coronary artery disease undergoing percutaneous coronary intervention: A real-world study.

OBJECTIVE: To assess the effectiveness and safety of bivalirudin compared with heparin monotherapy in elderly patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: Bivalirudin is recommended for periprocedural use in patients undergoing PCI who are of high bleeding risk. However, its safe and efficacious use in elderly patients, a typical high bleeding risk cohort, in real world practice is yet to be reported. METHODS: In this single center, real-world observational study, 4736 consecutive elderly patients who underwent PCI were enrolled. Of these, 1240 were treated with bivalirudin and 3496 with heparin according to the periprocedural anticoagulation strategies of PCI. The primary outcome was 12-month net adverse clinical events (NACE) defined as a composite of cardiac death, myocardial infarction, stroke, revascularization, or any bleeding. Propensity score matching (PSM) was used to balance baseline characteristics between groups. RESULTS: After PSM, bivalirudin was found to be associated with lower rates of NACE (19.1% vs. 24.7%, p = 0.002), cardiac death (2.7% vs. 4.3%, p = 0.038), and any bleeding (10.0% vs. 12.9%, p = 0.023) compared to heparin monotherapy. No differences were found in the incidences of myocardial infarction, stroke, revascularization, stent thrombosis (0.1% vs. 0.1%, p = 1.000), and major bleedings (0.5% vs. 0.5%, p = 1.000) between the two patient groups. CONCLUSION: In this real-world observational study, periprocedural use of bivalirudin in elderly patients who underwent PCI was associated with less cardiac death and any bleeding compared to heparin monotherapy, without increased risk of stent thrombosis.

Inhaled nebulised unfractionated heparin for the treatment of hospitalised patients with COVID-19: A multicentre case series of 98 patients.

AIMS: To determine the safety and efficacy-potential of inhaled nebulised unfractionated heparin (UFH) in the treatment of hospitalised patients with COVID-19. METHODS: Retrospective, uncontrolled multicentre single-arm case series of hospitalised patients with laboratory-confirmed COVID-19, treated with inhaled nebulised UFH (5000 IU q8h, 10 000 IU q4h, or 25 000 IU q6h) for 6 ± 3 (mean ± standard deviation) days. Outcomes were activated partial thromboplastin time (APTT) before treatment (baseline) and highest-level during treatment (peak), and adverse events including bleeding. Exploratory efficacy outcomes were oxygenation, assessed by ratio of oxygen saturation to fraction of inspired oxygen (FiO2 ) and FiO2 , and the World Health Organisation modified ordinal clinical scale. RESULTS: There were 98 patients included. In patients on stable prophylactic or therapeutic systemic anticoagulant therapy but not receiving therapeutic UFH infusion, APTT levels increased from baseline of 34 ± 10 seconds to a peak of 38 ± 11 seconds (P < .0001). In 3 patients on therapeutic UFH infusion, APTT levels did not significantly increase from baseline of 72 ± 20 to a peak of 84 ± 28 seconds (P = .17). Two patients had serious adverse events: bleeding gastric ulcer requiring transfusion and thigh haematoma; both were on therapeutic anticoagulation. Minor bleeding occurred in 16 patients, 13 of whom were on therapeutic anticoagulation. The oxygen saturation/FiO2 ratio and the FiO2 worsened before and improved after commencement of inhaled UFH (change in slope, P < .001). CONCLUSION: Inhaled nebulised UFH in hospitalised patients with COVID-19 was safe. Although statistically significant, inhaled nebulised UFH did not produce a clinically relevant increase in APTT (peak values in the normal range). Urgent randomised evaluation of nebulised UFH in patients with COVID-19 is warranted and several studies are currently underway.

Can nebulised HepArin Reduce morTality and time to Extubation in patients with COVID-19 Requiring invasive ventilation Meta-Trial (CHARTER-MT): Protocol and statistical analysis plan for an investigator-initiated international meta-trial of prospective randomised clinical studies.

There is significant interest in the potential for nebulised unfractionated heparin (UFH), as a novel therapy for patients with COVID-19 induced acute hypoxaemic respiratory failure requiring invasive ventilation. The scientific and biological rationale for nebulised heparin stems from the evidence for extensive activation of coagulation resulting in pulmonary microvascular thrombosis in COVID-19 pneumonia. Nebulised delivery of heparin to the lung may limit alveolar fibrin deposition and thereby limit progression of lung injury. Importantly, laboratory studies show that heparin can directly inactivate the SARS-CoV-2 virus, thereby prevent its entry into and infection of mammalian cells. UFH has additional anti-inflammatory and mucolytic properties that may be useful in this context. METHODS AND INTERVENTION: The Can nebulised HepArin Reduce morTality and time to Extubation in Patients with COVID-19 Requiring invasive ventilation Meta-Trial (CHARTER-MT) is a collaborative prospective individual patient data analysis of on-going randomised controlled clinical trials across several countries in five continents, examining the effects of inhaled heparin in patients with COVID-19 requiring invasive ventilation on various endpoints. Each constituent study will randomise patients with COVID-19 induced respiratory failure requiring invasive ventilation. Patients are randomised to receive nebulised heparin or standard care (open label studies) or placebo (blinded placebo-controlled studies) while under invasive ventilation. Each participating study collect a pre-defined minimum dataset. The primary outcome for the meta-trial is the number of ventilator-free days up to day 28 day, defined as days alive and free from invasive ventilation.

Effectiveness and Safety of Twice- Versus Thrice-Daily Subcutaneous Heparin for Venous Thromboembolism Prophylaxis at a Large Academic Medical Center.

BACKGROUND: Dosing variation of subcutaneous unfractionated heparin (UFH) exist for venous thromboembolism prophylaxis (VTEP). OBJECTIVE: The purpose of this study was to compare the safety and effectiveness of thrice-daily (TID) versus twice-daily (BID) administration of UFH during a heparin shortage for VTEP. METHODS: A single-center retrospective analysis was conducted in patients with orders for BID subcutaneous UFH during a heparin shortage from September 1, 2019, to February 4, 2020. These patients were matched to patients with TID subcutaneous UFH orders from January 1, 2019, to May 31, 2019. The primary outcome was the incidence of deep-vein thrombosis or pulmonary embolism confirmed by imaging during hospitalization. The secondary outcome was the incidence of major or clinically relevant nonmajor bleeding events as defined by International Society on Thrombosis and Haemostasis (ISTH) definitions. RESULTS: A total of 277 patients with orders for BID UFH and meeting inclusion criteria were evaluated and matched to patients who received TID UFH. After the exclusion criteria were implemented, 510 patients remained in the TID group. The primary outcome occurred in 4% of patients in the BID group and 3% in the TID group (P = 0.645). Major bleeding or clinically relevant nonmajor bleeding events occurred in 10% of patients in the BID group and 8% in the TID group (P = 0.310). CONCLUSION AND RELEVANCE: There was no difference in effectiveness or safety of TID versus BID subcutaneous UFH for VTEP. During a heparin shortage, transitioning patients to BID UFH for VTEP to conserve supply may be considered.