Prophylactic Enoxaparin in Critically Ill Trauma Patients: Evaluation of the Initial Dose

Background: Trauma patients are at increased risk of developing venous thromboembolism given alterations in the coagulation cascade. Chemoprophylaxis with standard dosing of enoxaparin 30 mg subcutaneously twice daily has evolved to incorporate the use of anti-factor Xa (AFXa) trough level monitoring given concerns for decreased enoxaparin bioavailability in this patient population. Current available evidence suggests low rates of goal AFXa trough level achievement with standard enoxaparin dosing. Our study aims to identify the incidence of critically ill trauma patients that did not achieve goal AFXa trough levels and attempts to identify predictors that may influence the lack of achievement of goal levels. Methods: This was a retrospective, cohort analysis performed at a single academic medical center. Adult patients 18 years or older admitted to the surgical intensive care unit secondary to trauma who were initiated on standard prophylactic enoxaparin and had at least 1 AFXa trough level representative of steady state were included. Patient demographics and clinical data were collected, and descriptive statistics were utilized. All statistical tests were 2-tailed and a P < .05 was considered significant. Variables with a P < .10 on univariable analysis were included in a multivariable logistic regression analysis. Results: A majority of our patient population did not achieve goal AFXa trough levels while receiving standard doses of prophylactic enoxaparin (82.4% [108/131]). Sub-target AFXa levels were associated with higher creatinine clearance values. Positive predictors of obtaining target AFXa levels included automobile versus pedestrian mechanism of injury and requiring an enoxaparin dose escalation to at least 40 mg twice daily. Conclusions: Our study found low rates of achievement of goal AFXa trough levels in critically ill trauma patients receiving standard prophylactic enoxaparin dosing. Certain variables were identified as negative and positive predictors for achievement of goal AFXa trough levels, although the biologic plausibility of these predictors is questionable and requires further investigation.

Unexpectedly High Efficacy of SARS-CoV-2 BNT162b2 Vaccine in Liver versus Kidney Liver Transplant Recipients—Is It Related to Immunosuppression Only?

The BNT162b2 vaccine is reportedly effective in preventing severe disease in more than 90% of the general population, but its efficacy in transplant recipients remains controversial. We aimed to determine the immune response to the BNT162b2 vaccine in kidney (KTRs) and liver transplant recipients (LTRs). In this retrospective cohort study, we included randomly 65 KTRs and 65 LTRs, who received two 30 μg doses of BNT162b2 vaccine in 3-to6-week intervals. We analyzed the anti-SARS-CoV-2 spike protein IgG antibody (anti-S1 Ab) titer, biochemical liver and renal tests, immunosuppressive drug trough level, and clinical follow up 4–6 weeks after the first dose and 4–8 weeks after the second dose. The level of protective antibodies was 57.1% in KTRs and 88.9% in LTRs after the second dose. The anti-S1 Ab response was significantly associated with sex, age, and history of COVID-19. A tacrolimus dose at vaccination but not its trough level was significantly correlated with the increase in anti-S1 Ab titer after the second vaccine dose in LTRs. Rejection episodes did not occur after vaccination. Our results showed a higher than previously reported humoral response to the BNT162b2 vaccine in KTRs and LTRs, which was dependent upon age, type of transplanted organ, and immunosuppression.

Association of vancomycin trough concentration on the treatment outcome of patients with bacteremia caused by Enterococcus species

Background Pharmacokinetic-pharmacodynamic (PK/PD) targets of vancomycin therapy have been recognized for methicillin-resistant Staphylococcus aureus infections but not for other gram-positive bacterial infections. Therefore, we investigated whether vancomycin concentration targets such as the trough level and ratio of the area under the curve to minimum inhibitory concentration (AUC/MIC) are associated with the treatment outcome in enterococcal bacteremia. Methods A retrospective cohort analysis enrolled patients with bacteremia caused by vancomycin-susceptible Enterococcus faecium and Enterococcus faecalis who were treated with vancomycin from January 2007 to December 2017 at a tertiary hospital located in Seoul, South Korea. Patients without vancomycin concentrations were excluded from the study. The primary outcome was 28-day all-cause mortality. Results A total of 37 patients were enrolled—26 with E. faecium infection and 11 with E. faecalis infection. The 28-day all-cause mortality rate was 21.6 %. In univariate analysis, vancomycin trough level (≤ 15 µg/mL; p = 0.042), age (p = 0.044), and septic shock (p = 0.049) were associated with 28-day mortality but not AUC24/MIC (> 389; p = 0.479). In multivariate analysis, vancomycin trough concentration (≤ 15 µg/mL; p = 0.041) and younger age (p = 0.031) were associated with 28-day mortality in patients with enterococcal bacteremia. Conclusions In this study, a vancomycin trough level of 15 µg/mL or lower was associated with 28-day mortality in enterococcal bacteremia. However, relatively large prospective studies are needed to examine the efficacy of vancomycin PK/PD parameters in patients with enterococcal bacteremia.

Vancomycin-induced nephrotoxicity in non-intensive care unit pediatric patients

Previous data suggested several risk factors for vancomycin-induced nephrotoxicity (VIN), including higher daily dose, long-term use, underlying renal disease, intensive care unit (ICU) admission, and concomitant use of nephrotoxic medications. We conducted this study to investigate the prevalence and risk factors of VIN and to estimate the cut-off serum trough level for predicting acute kidney injury (AKI) in non-ICU pediatric patients. This was a retrospective, observational, single-center study at Samsung Medical Center tertiary hospital, located in Seoul, South Korea. We reviewed the medical records of non-ICU pediatric patients, under 19 years of age with no evidence of previous renal insufficiency, who received vancomycin for more than 48 h between January 2009 and December 2018. The clinical characteristics were compared between patients with AKI and those without to identify the risk factors associated with VIN, and the cut-off value of serum trough level to predict the occurrence of VIN was calculated by the Youden’s index. Among 476 cases, 22 patients (4.62%) developed AKI. The Youden’s index indicated that a maximum serum trough level of vancomycin above 24.35 μg/mL predicted VIN. In multivariate analysis, longer hospital stay, concomitant use of piperacillin-tazobactam and serum trough level of vancomycin above 24.35 μg/mL were associated independently with VIN. Our findings suggest that concomitant use of nephrotoxic medication and higher serum trough level of vancomycin might be associated with the risk of VIN. This study suggests that measuring serum trough level of vancomycin can help clinicians prevent VIN in pediatric patients.

Efficacy of Intravenous Immunoglobulin Replacement Therapy in Patients with Predominantly Antibody Deficiency

Background Intravenous immunoglobulin G (IVIG) has been used as an antibody replacement therapy in primary immunodeficiency (PID) for more than 50 years. Most routinely, IVIG is used in patients with predominantly antibody deficiency such as: X-linked Agammaglobulinemia, common variable immunodeficiency and combined immunodeficiency such as: severe combined immunodeficiency. Aim To evaluate the efficacy and safety of regular IVIG therapy among patients with predominantly antibody deficiency in terms of frequency of infection and adverse effects. Methods Thirty patients diagnosed with predominantly antibody deficiency were recruited from the Pediatric Allergy and Immunology Unit, Children’s Hospital, Ain Shams University. These patients were followed up for one year in order to evaluate the frequency of infection and and adverse reactions of regular monthly IVIG therapy. The adequacy of IVIG dose was evaluated by the trough level of serum immunoglobulin G (IgG). Results Of the 30 patients, 21 (70%) were males and 9 (30%) were females. They had a median age of 87 months (range:15-294). Their median age at presentation and at diagnosis were 36 months (range :3-168) and 87 months (range:15-204) respectively. The mean ± SD of serum IgG before commencement of IVIG and after were 265.10 ± 108.39mg/dl and 572.04 ± 186.72 respectively. The rate of major infection dropped after starting replacement therapy with a median of 2 (1-2) before and 0 (0-1) after treatment. In spite of the reduction in the rate of pneumonia occurrence in patients with IgG trough level &gt;500 mg/dl, it had no statistical significance. This could be attributable to small sample size. One patient developed anaphylaxis and was shifted to another brand. Conclusion IVIG is a safe and effective drug for patients with predominantly antibody deficiency. Compliance, adherence to therapy and appropriate dosage is needed to achieve better infection control.

Pharmacokinetics of Factor VIII Level in Patients Hemophilia A in Relation to Clinical and Radiological Outcomes

Background The benefit of pharmacokinetics (PK) -guided dosing is that both prophylactic and “on demand” dosing will be based on actual FVIII trough and peak levels instead of current FVIII estimates based on body weight and in-vivo recovery based dosing. Knowledge will increase with regards the relationship between FVIII level and bleeding in individual patients. The dose and frequency of factor VIII for patients on prophylaxis should only be reduced if clinically justified and impact should be monitored with regard to bleeding events, bleeding pattern and joint status. Objective To assess the trough and peak level of factor VIII in patients with hemophilia A on low dose prophylaxis and its impact on the clinical and radiological joint status. Patients and Methods A cross sectional study was performed in Ain-Shams University, Pediatrics Hospital, Hemophilia Clinic. It included 25 children and adolescents with hemophilia A on prophylactic factor VIII during the period from September 2018 to August 2019. Factor VIII used was recombinant 3rd generation with a dose of 45 IU/Kg/week rounded to the nearest 500IU. Trough level of factor VIII was done before prophylactic dose and peak level was done one hour postinfusion through chromogenic assay using STAGO-Immuno-Def VIII reagent. Clinical joint score and Functional Independence Score of Hemophilia (FISH) were done. Radiological joint scores were done using conventional x-ray, ultrasound and MRI. Cut-off level of trough levels was studied at 1% and 1%-5% of factor VIII. Results Patients were classified into 3 groups,4 patients (21.1%) had trough level &lt;1%, 13 patients (68.4%) had trough level between 1%-5%, 2 patients (10.5%) had trough level &gt; 5%. No significant difference between trough level of factor VIII and clinical joint scores and FISH scores of patients. Median score of the worst joint of patients with trough level &gt;5% was 5 in comparison to 8 and 7 in patients with trough level 1%-5% and &lt;1% respectively. Mean FISH of patients with trough level &gt;5% was 9.50 ± 2.12 in comparison to 12.92 ± 5.41 and 11.00 ± 3.56 for patients with troughs 1%-5% and &lt;1% that was respectively. Comparison between groups with different trough level of factor VIII according to X-ray scores of patients showed no significant difference Conclusion Low trough levels alone did not warrant intensification of the prophylaxis regimen; rather, the dose and dosing frequency should be adjusted based on individual’s bleeding pattern and many other factors as shown in our study the insignificant relation between trough levels of factor VIII and clinical and radiological outcomes.. More frequent factor VIII monitoring and incorporation into population based PK are warranted.

Intrapatient Variability in Tacrolimus Trough Levels Over 2 Years Affects Long-Term Allograft Outcomes of Kidney Transplantation

This study aimed to determine the impact of tacrolimus (TAC) trough level (C0) intrapatient variability (IPV) over a period of 2 years after kidney transplantation (KT) on allograft outcomes. In total, 1,143 patients with low immunologic risk were enrolled. The time-weighted coefficient variability (TWCV) of TAC-C0 was calculated, and patients were divided into tertile groups (T1: &lt; 24.6%, T2: 24.6%–33.7%, T3: ≥ 33.7%) according to TAC-C0-TWCV up to post-transplant 1st year. They were classified into the low/low, low/high, high/low, and high/high groups based on a TAC-C0-TWCV value of 33.7% during post-transplant 0–1st and 1st–2nd years. The allograft outcomes among the three tertile and four TAC-C0-TWCV groups were compared. The T3 group had the highest rate of death-censored allograft loss (DCGL), and T3 was considered an independent risk factor for DCGL. The low/low group had the lowest and the high/high group had the highest risk for DCGL. Moreover, patients with a mean TAC-C0 of ≥5 ng/ml in the high/high group were at the highest risk for DCGL. Thus, TAC-IPV can significantly affect allograft outcomes even with a high mean TAC-C0. Furthermore, to improve allograft outcomes, a low TAC-IPV should be maintained even after the first year of KT.