Challenges in Management of VTE in Children With Cancer: Risk Factors and Treatment Options

Hospital-acquired venous thromboembolism during invasive mechanical ventilation in children: a single-center, retrospective cohort study

BACKGROUND

Invasive mechanical ventilation (IMV) has been independently associated with hospital-acquired venous thromboembolism (HA-VTE) among critically ill children, including extremity deep venous thrombosis and pulmonary embolism.

OBJECTIVES

We aimed to characterize the frequency and timing of HA-VTE following IMV exposure.

METHODS

This was a single-center, retrospective cohort study including children aged <18 years, hospitalized in a pediatric intensive care unit, undergoing mechanical ventilation for >24 hours from October 2020 through April 2022. Encounters with an existing tracheostomy or receiving treatment for HA-VTE prior to endotracheal intubation were excluded. The primary outcomes characterized clinically-relevant HA-VTE, including timing after intubation, location, and the presence of known hypercoagulability risk factors. Secondary outcomes were IMV exposure magnitude, defined by IMV duration and ventilator parameters (ie, volumetric, barometric, and oxygenation indices).

RESULTS

Of 170 consecutive, eligible encounters, 18 (10.6%) experienced HA-VTE at a median of 4 days (IQR, 1.4-6.4) following endotracheal intubation. Those with HA-VTE had an increased frequency of a prior venous thromboembolism (27.8% vs 8.6%, P = .027). No differences in frequency of other HA-VTE risk factors (ie, acute immobility, hematologic malignancy, sepsis, and COVID-19-related illness), presence of a concurrent central venous catheter, or the magnitude of IMV exposure were noted.

CONCLUSION

Children undergoing IMV experience HA-VTE at markedly higher rates than previously estimated in the general pediatric intensive care unit population after endotracheal intubation. While prospective validation is needed, these findings are an important step toward informing the development of risk-stratified thromboprophylaxis trials in critically ill children.

Effect of exercise therapy on PICC-associated venous thromboembolism: A meta-analysis

BACKGROUND

Peripherally inserted central catheter (PICC) is widely used in clinical practice because of its long retention time and easy maintenance. However, PICC-associated venous thromboembolism (VTE) is the most serious complication of PICC. Guidelines recommend exercise therapy to prevent PICC-associated VTE. However, inconsistent findings have been reported across the literature. This study conducted a meta-analysis to further evaluate the effect of exercise therapy on PICC-associated VTE.

METHODS

We searched CNKI, Wanfang database, Chinese Science and Technology Journal Full Text Database, PubMed, Embase, Web of Science and Cochrane Library databases and included all randomized controlled trials (RCTs) of exercise therapy for the prevention of PICC-associated VTE. Two investigators independently screened the literature, extracted information, and evaluated the risk of bias for eligible RCTs. Meta-analysis was conducted by RevMan5.4 software.

RESULTS

Eleven RCTs were included, including 1919 patients. Meta-analysis showed that the incidence of PICC-associated VTE was lower in the exercise therapy group than in the usual care group (RR = 0.30, 95% CI: 0.22-0.41, p < 0.00001).Exercise therapy increased the axillary vein maximum velocity (SMD = 0.93, 95% CI: 0.58-1.28, p < 0.00001) and the axillary vein time-mean flow velocity (SMD = 0.86, 95% CI: 0.53-1.20, p < 0.00001). Subgroup analysis showed statistically significant differences for the incidence of PICC-associated VTE for intervention times<4 weeks (RR = 0.26, 95% CI: 0.17-0.40, p < 0.00001) and intervention times≥4 weeks (RR = 0.35, 95% CI: 0.22-0.54, p < 0.00001). For axillary vein maximum velocity, the difference was statistically significant for both intervention time <4 weeks (SMD = 0.73, 95% CI: 0.55-0.91, p < 0.00001) and intervention time ≥4 weeks (SMD = 1.18, 95% CI: 0.18-2.19, p = 0.02). For axillary vein time-mean flow velocity, the intervention time <4 weeks (SMD = 0.75, 95% CI: 0.46-1.04, p < 0.00001), and the difference was statistically significant; while ≥4 weeks, the difference was not statistically significant (SMD = 1.14, 95% CI: -0.07 to 2.35, p = 0.06).

CONCLUSIONS

Exercise therapy improved venous blood flow velocity and effectively reduced the incidence of PICC-associated VTE. However, RCTs with large samples and high quality are needed to further evaluate the effectiveness of exercise therapy in PICC patients.

Risk Factors of Venous Thromboembolism in Inpatients With Colorectal Cancer in China

To explore the risk factors for venous thromboembolism (VTE) in inpatients with colorectal cancer. The demographic factors, comorbidities, and hematological indices of patients with colorectal cancer treated in our hospital from 2016 to 2021 were collected and recorded. Venous thromboembolism events, including deep venous thrombosis and/or pulmonary embolism, were recorded and the patients were divided into the VTE group and the non-VTE group. We compared clinical data between the two groups and explored risk factors for VTE. Comparing the clinical data of 293 cases of non-VTE group and 235 cases of VTE group, we found significant differences in age, smoking, temperature, amount of blood loss, differentiation degree, peripherally inserted central catheter (PICC), radiotherapy, anemia, infection, white blood cell count, prothrombin time (PT), PT%, prothrombin ratio, international normalized ratio, thrombin time, CA199 and CEA between the two groups (P < 0.05). Logistic regression analysis showed that age (P = 0.0444), temperature (P = 0.0317), amount of blood loss (P = 0.0067), PICC (P < 0.0001), chemotherapy (P = 0.0459), anemia (P = 0.0007), international normalized ratio (P = 0.003) and CA199 (p = 0.0234) were independent risk factors for VTE. Receiver operating characteristic curve analysis showed that the amount of blood loss predicted thrombosis better (AUC = 0.778, P < 0.001), when the cutoff value was 20 mL, the sensitivity was 76.17%, and the specificity was 79.18%, respectively. And PICC predicted thrombosis better (AUC = 0.808, P < 0.001), the sensitivity was 70.21%, and the specificity was 91.47%, respectively. Clinical parameters are associated with VTE in inpatients with colorectal cancer, which will help to guide clinicians to take effective measures to improve the patients' prognosis.

Direct Oral Anticoagulants for the Prevention and Acute Treatment of Cancer-Associated Thrombosis

Cancer is a major risk factor for venous thromboembolism (VTE), and cancer-associated thrombosis (CAT) constitutes approximately 15-25% of all VTE cases. For decades, the standard treatment for CAT used to be daily subcutaneous low molecular weight heparin (LMWH). Data on the safety and efficacy of the direct oral anticoagulants (DOACs) in this population emerged only in recent years and specific DOACs were included into recent guidelines recommendations. In this narrative review of the literature, we reported the results of the phase III randomized controlled trials that evaluated the DOACs for the prevention and the acute treatment of CAT. For the acute phase treatment, the anti-Xa inhibitors (apixaban, edoxaban, rivaroxaban) showed better efficacy than LMWH in preventing VTE recurrence; however, rivaroxaban and edoxaban were also associated with an increased risk of bleeding events. For primary prevention of CAT in ambulatory cancer patients starting chemotherapy, apixaban and rivaroxaban showed better efficacy than placebo but a trend towards higher bleeding rates. Recent guidelines suggest the DOACs for the treatment of CAT in selected cancer patients (eg, low bleeding risk, no luminal gastrointestinal or genitourinary malignancies, no interfering medications). The DOACs are also suggested for primary thromboprophylaxis in selected ambulatory cancer patients at high risk of VTE (eg, Khorana score ≥2 prior to starting new chemotherapy, low bleeding risk, no interfering medications).