Deep vein thrombosis screening in pediatric orthopedic patients

Deep vein thrombosis (DVT) is an important clinical condition that leads to subsequent morbidity and mortality in children, particularly those who involved operative procedures. The preoperative assessment for DVT in children may vary among different population risk factors and types of surgery. This study aimed to evaluate the screening methods for DVT in pediatric orthopedic patients.

We performed a retrospective cohort study of orthopedic patients aged <18 years at Ramathibodi Hospital, Bangkok, Thailand, from 2015 to 2019. The inclusion criteria were children scheduled for orthopedic surgery; who performed a D-dimer test, Wells score, and Caprini score; and who underwent Doppler ultrasonography for DVT screening. The exclusion criteria were incomplete data or inconclusive ultrasonographic results. Age and results of the D-dimer test, Wells score, and Caprini score were collected from all patients. The outcome assessment was ultrasound-proven DVT. The screening abilities of each test were analyzed in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio (LR) for positive and negative tests, and area under the receiver operating characteristic curve (AUC).

A total of 419 children were included in the study. Five (1.19%) patients were diagnosed with DVT. The mean age was 10.16 ± 4.83 years. D-dimer ≥500 ng/mL had a sensitivity of 100% (95% CI: 47.8%-100%), a specificity of 36.7% (95% CI: 32.1%-41.6%), a PPV of 1.9% (95% CI: 0.6%-4.3%), and an NPV of 100% (95% CI: 97.6%-100%). Wells score ≥3 demonstrated a sensitivity of 0% (95% CI: 0%-52.2%), a specificity of 99.3% (95% CI: 97.9%-99.9%), and an LR for a negative test of 1.00 (95% CI: 1.00-1.01). Caprini score ≥11 had a sensitivity of 0% (95% CI: 0%-52.2%) and a specificity of 99.8% (95% CI: 98.7%-100%). The parallel test included D-dimer ≥500 ng/mL, Wells score ≥3, or Caprini score ≥11 points, generating a sensitivity of 100% (95% CI: 47.8%-100%), a specificity of 36.7% (95% CI: 32.1%-41.6%), an LR for a positive test of 1.58 (95% CI: 1.47-1.70), and an AUC of 0.68 (95% CI: 0.66-0.71).

The D-dimer test exhibited moderate ability in predicting the development of DVT among pediatric orthopedic patients requiring surgery. The Wells score and Caprini score had low performance in identifying hospitalized children at increased risk of DVT events.