Anaphylaxis to Protamine During a Carotid Endarterectomy.

Protamine sulfate is commonly used to reverse the anticoagulant effects of unfractionated heparin (UFH) during surgical procedures, but its administration can sometimes trigger severe adverse reactions, including life-threatening anaphylaxis. We present the case of a 77-year-old male undergoing carotid endarterectomy who developed profound hypotension and tachycardia following protamine infusion. Anaphylaxis was confirmed by elevated tryptase levels. This case emphasizes the importance of vigilant monitoring during protamine administration, particularly in high-risk patients, and highlights the need to consider alternative reversal strategies to enhance patient safety.

Time in Therapeutic Range of Unfractionated Heparin-Based Therapy in Critically Ill Patients with COVID-19 Pneumonia.

Purpose: Anticoagulation therapy aims to improve the outcome of critically ill patients with severe COVID-19-associated pneumonia. Activated partial thromboplastin time (aPTT) is commonly used to maintain the target therapeutic range of continuous infusion of unfractionated heparin (UFH). The UFH infusion efficacy can be evaluated by determining the time in therapeutic range (TTR) using a modified Rosendaal method. The present study's primary aim was to evaluate TTR based on the aPTT in critically ill patients with severe forms of COVID-19 pneumonia and its influence on survival. The secondary aim was to evaluate the time spent above (TATR) and below the therapeutic range (TBTR). Patients and Methods: We performed a retrospective analysis of critically ill patients with COVID-19-associated pneumonia. All patients received a continuous infusion of UFH from the 2nd to 8th day since admission to the ICU. TTR, TATR, and TBTR were calculated using the modified Rosendaal method, and survival days were analyzed by regression (censored after 60 days). Results: Of 103 patients, the median TTR was 49% (IQR 38-63%), TATR 11% (IQR 5-20%), and TBTR 33% (IQR 22-51%). The regression analysis indicated a positive impact of higher TTR and TATR on the number of survival days [ß=0.598 (p=0.0367) and ß=1.032 (p=0.0208), respectively] and a negative impact of higher TBTR [ß=-0.681 (p=0.0033)] on the number of survival days. Conclusion: Higher TTR and TATR were associated with better survival of critically ill patients with a severe course of COVID-19-associated pneumonia. Higher TBTR was associated with worse survival in these patients.

Increased white blood cell count is associated with an increased demand for unfractionated heparin during veno-arterial extracorporeal oxygenation in lung transplantation.

BACKGROUND: This retrospective observational study aimed to examine whether clinical inflammatory parameters were associated with the requirement dosage of unfractionated heparin (UFH) to maintain the range of ACT in veno-arterial extracorporeal membrane oxygenation (V-A ECMO) during lung transplantation surgery. METHODS: Among all patients who underwent lung transplantation using V-A ECMO from January 2021 to May 2022, 27 patients were included. These patients were divided into two groups based on whether the infusion rate of UFH was increased from the initial infusion rate (7-8 units/kg/h) (increased group, n = 10) or the infusion rate was maintained or decreased (non-increased group, n = 17). The infusion rate was adjusted with an activated clotting time (ACT) target of 160-200 s. RESULTS: At 1-2 h after starting ECMO, ACT was significantly lower (179.0 (166.5-188.5) versus 224.0 (193.0-242.0) sec, p = 0.006) and white blood cell (WBC) counts were higher in the increased group (12.6 ± 3.3 versus 9.5 ± 4.0 × 103/µL, p = 0.046). The UFH infusion rates were higher in the increased group during the surgery. The cutoff value of WBC count at 1-2 h after starting ECMO for discriminating the need for increasing the UFH dosage was determined as 10.2 × 103/µL (sensitivity 90.0%, specificity 58.8%, area under the curve 0.712) and discrimination of this cut-off value was confirmed as statistically significant (p = 0.018). CONCLUSION: These data suggested that WBC count was associated with the requirement of an increase in the UFH infusion rate of V-A ECMO during lung transplantation surgery. Further evaluation is necessary to clarify the role of WBC count in determining the optimal UFH dosage.

Relation between antithrombin-III activity and activated clotting time for cardiopulmonary bypass.

Heparin resistance (HR) is observed before cardiopulmonary bypass (CPB), despite with normal antithrombin III (AT-III) levels. The relationships between preoperative AT-III activity and activated clotting time (ACT) after the first heparin dose should be clarified. We retrospectively analyzed the data of 818 patients who underwent CPB surgery, with the initial heparin of 300, 400, and 500 IU/kg, between 2017 and 2021. We defined HR as the failure to achieve ACT after the initial heparin dose (Post ACT) of > 480 s.There were no significant correlations between the AT-III activity and Post ACT in all patients, including 143 patients with AT-III activity < 80% and 675 patients with AT-III activity of ≥ 80%. Also, there were no significant correlations between the AT-III activity and Post ACT in 74 patients who received heparin of 300 IU/kg, in 186 patients with 400 IU/kg, and in 339 patients with 500 IU/kg. After identifying smoking, HR, activated partial thromboplastin time, fibrinogen degradation products (FDP), and ACT as influencing factors, multiple comparisons using the Steel-Dwass test showed significant difference in FDP and HR among the patients who received heparin of 300 IU/kg, 400 IU/kg, and 500 IU/kg. There is no association between preoperative AT-III activity and ACT after the first heparin administration for CPB, even in different dose of heparin. Rather, the higher the initial UFH dose is, the higher ACT may be, regardless of the AT-III activity.

Comparison of pain after prophylactic anticoagulant injections to prevent venous thromboembolism.

Subcutaneous injection of unfractionated heparin (UH) or low molecular weight heparin (LMWH) is frequently utilized for venous thromboembolism chemoprophylaxis. We previously discovered that nurses believe patients experience more pain with UH compared to the LMWH enoxaparin; however, no published studies that are appropriately powered exist comparing pain associated with subcutaneous chemoprophylaxis. Our objective was to assess if differences exist in pain associated with subcutaneous administration of UH and enoxaparin. We conducted an observational study of patients who underwent major abdominal surgery between 11/2017-4/2019. All patients received one of three prophylactic regimens: (1) UH only, (2) Initial dose of UH followed by enoxaparin, or (3) enoxaparin only. Of the 74 patients observed, 40 patients received UH followed by enoxaparin, 17 received UH only, and 17 received enoxaparin only. There was a significant difference in patients' mean perceived pain between subcutaneous UH and enoxaparin injections (mean post-injection pain after UH 3.3 vs. enoxaparin 1.5; p < 0.001). There was no significant difference in perceived pain for patients who received consecutive UH or enoxaparin injections. Differences in pain associated with different chemoprophylaxis agents may be an unrecognized driver of patient refusals of VTE chemoprophylaxis and may lead to worse VTE outcomes.

Standardization of Anti-Xa Assay and its Comparison with Activated Partial Thromboplastin Time for Monitoring Unfractionated Heparin Therapy.

Monitoring of anticoagulant activity of unfractionated heparin (UFH) is primarily done with activated partial thromboplastin time (aPTT), which is affected by many factors. Anti-Xa assays are considered to overcome these factors and may provide a better method for monitoring patients on UFH with a narrow therapeutic range. This study aimed to compare the effectiveness of aPTT and anti-Xa assays in UFH monitoring. A prospective non-randomized study was carried out in two stages: first, the anti-Xa assay was standardized using kit instructions; each sample was then analyzed by both tests. The outcomes of the two assays were compared and assessed for agreement of maintaining therapeutic anticoagulant levels. These levels for anti-Xa assay were between 0.3 and 0.7 IU/ml, while it was 1.5-2.5 times the control for aPTT assay. Below this range was regarded as subtherapeutic, and above this as supratherapeutic. A total of 90 samples were tested and analyzed using both assays. Most of them (> 70%) were noted to be in subtherapeutic levels with both tests. The overall concordance was 73.3%, and the estimated kappa value was 0.483 (0.396-0.57). The correlation between aPTT and anti-Xa assay was 0.74 (p < 0.001). With anti-Xa levels in the therapeutic range, aPTT levels were in subtherapeutic in 60% and supratherapeutic in 13.3% cases. Although both the testing strategies had a good agreement and correlation, discordance was observed in interpretative values with anti-Xa levels in therapeutic range and aPTT levels in non-therapeutic range. Its clinical implications need to be evaluated further in future studies.

Post-procedural Anticoagulation With Unfractionated Heparin in Acute Coronary Syndrome: Insight from the STOPDAPT-3 Trial.

The current guidelines for acute coronary syndrome (ACS) discourage the use of anticoagulation after percutaneous coronary intervention (PCI) without specific indications, although the recommendation is not well supported by evidence. In this post hoc analysis of the ShorT and OPtimal Duration of Dual AntiPlatelet Therapy-3 (STOPDAPT-3) trial, 30-day outcomes were compared between the 2 groups with and without post-PCI heparin administration among patients with ACS who did not receive mechanical support devices. The co-primary end points were the bleeding end point, defined as the Bleeding Academic Research Consortium type 3 or 5 bleeding, and the cardiovascular end point, defined as a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke. Among 4,088 patients with ACS, 2,339 patients (57.2%) received post-PCI heparin. The proportion of patients receiving post-PCI heparin was higher among those with ST-elevation myocardial infarction compared with others (72.3% and 38.8%, p <0.001), and among patients with intraprocedural adverse angiographic findings compared with those without (67.6% and 47.5%, p <0.001). Post-PCI heparin compared with no post-PCI heparin was associated with a significantly increased risk of the bleeding end point (4.75% and 2.52%, adjusted hazard ratio 1.69, 95% confidence interval 1.15 to 2.46, p = 0.007) and a numerically increased risk of the cardiovascular end point (3.16% and 1.72%, adjusted hazard ratio 1.56, 95% confidence interval 0.98 to 2.46, p = 0.06). Higher hourly dose or total doses of heparin were also associated with higher incidence of both bleeding and cardiovascular events within 30 days. In conclusion, post-PCI anticoagulation with unfractionated heparin was frequently implemented in patients with ACS. Post-PCI heparin use was associated with harm in terms of increased bleeding without the benefit of reducing cardiovascular events. Trial identifier: STOPDAPT-3 ClinicalTrials.gov number, NCT04609111.

To Compare the Effectiveness of Low-Molecular-Weight Heparin and Unfractionated Heparin in Reducing Lower Limb Girth in Deep Vein Thrombosis.

INTRODUCTION: Treating deep vein thrombosis (DVT) using a once-daily dose of enoxaparin offers greater convenience and the possibility of home-based care for certain patients, as opposed to a continuous infusion of unfractionated heparin (UFH). The study aimed to determine the most cost-effective thromboprophylaxis between low-molecular-weight heparin (LMWH) and UFH for hospitalized patients. MATERIALS AND METHODS: After obtaining clearance from the institutional ethical committee, the study was conducted in the Department of General Surgery, Sri Devaraj Urs Medical College, over a period of six months. Informed consent was obtained from all 46 patients included in this study. The participants were divided into two groups: group A received LMWH and group B received UFH. RESULTS: The mean age in group A was 59.8 + 10.6 years and in group B was 54.9 + 12.3 years. There was no significant difference in the girth of the lower limb between the groups during the follow-up period (p > 0.05). In group A, there was a highly significant reduction in lower limb girth from day one to day five (p < 0.0001), day five to day 10 (p < 0.0001), and day one to day 10 (p < 0.0001). In group B, there was no significant reduction from day one to day five (p = 0.06), but there was a significant reduction from day five to day 10 (p = 0.001) and day one to day 10 (p = 0.001). CONCLUSION: Treatment with LMWH as an anticoagulant significantly reduced the lower extremity girth and thrombus thickness in cases of DVT when compared to UFH.

Anticoagulation Management Post Pulmonary Embolism.

Pulmonary embolus (PE) carries a significant impending morbidity and mortality, especially in intermediate and high-risk patients, and the choice of initial anticoagulation that allows for therapeutic adjustment or manipulation is important. The preferred choice of anticoagulation management includes direct oral anticoagulants. Vitamin K antagonists and low-molecular-weight heparin are preferred in special populations or selected patients such as breastfeeding mothers, those with end-stage renal disease, or obese patients, among others. This article reviews the primary and longer-term considerations for anticoagulation management in patients with PE and highlights special patient populations and risk factor considerations.

The imprecision of measuring activated clotting time (ACT) from the guiding catheter during percutaneous coronary interventions.

BACKGROUND: Finding the balance between the reduction in ischemic events and bleeding complications is crucial for the success of percutaneous coronary intervention (PCI). The activated clotting time (ACT) is used routinely worldwide to monitor and titrate anticoagulation therapy with unfractionated heparin (UFH) during the procedure. OBJECTIVES: We aimed to test the accuracy of ACT measurements from the guiding catheter compared to the arterial access sheath. METHODS: Patients undergoing PCI with UFH therapy were prospectively enrolled. Blood samples were drawn from the coronary guide catheter and the arterial access sheath. ACT values were determined in the same ACT machine, and potential interactions with clinical variables were analyzed. RESULTS: The study included 331 patients with post PCI ACT measurements. The mean ACT value of the catheter samples was statistically higher than the arterial access sample [294 ± 77 s Vs. 250 ± 60 s, p < 0.001]. The mean difference between the guiding catheter and the arterial line sheath samples was 43 ± 27 s (P < 0.001). We found that in 101/331 [30 %] patients the ACT from the guiding catheter was above 250 s, while from the access sheath it was below 250 s. Notably, in 40/331 [12 %] the ACT from the guiding catheter was above 200 s, while from the access sheath it was below 200 s. CONCLUSIONS: Large proportion of patient may be considered to have therapeutic ACT if measured from guide catheter during PCI, while the corresponding ACT from arterial sheath is subtherapeutic. This difference may have clinical and safety significance.