Michigan Risk Score for PICC-Related Thrombosis

Michigan Risk Score for PICC-related Thrombosis

Active Cancer with Chemotherapy

History of VTE

White Blood Cell Count

Number of PICC Lumens

BMI

Michigan Risk Score: –

Awaiting input

Select all criteria to compute the score.

Predicts risk of DVT in patients with peripherally inserted central catheter (PICC).

Why Use

Use prior to inserting a PICC to estimate the risk of upper-extremity/catheter-related thrombosis. Can help support testing for thrombosis (e.g. ultrasound) in patients with vague symptoms but high risk for DVT. Can support decision for longer duration of anticoagulation in patients with confirmed DVT related to PICC (higher risk – longer duration).

When to Use

Adult patients ≥18 years of age admitted to a medical service (i.e., not surgical). Do not use in pregnant patients.

Formula

Addition of the selected points: Variable Points Another central venous catheter present* No 0 Yes +1 WBC >12.0 × 10⁹/µL* No 0 Yes +1 Number of PICC lumens 1 0 2 +1 3–4 +2 History of VTE Never 0 Yes, >30 days prior +2 Yes, within 30 days +3 Active cancer (on chemotherapy or admitted for cancer-related reasons) No 0 Yes +3 *At the time of index PICC placement.

Pearls / Pitfalls

The Michigan Risk Score for PICC-Related Thrombosis helps estimate the risk of developing upper-extremity thrombosis in patients that receive peripherally inserted central catheters (PICCs). Strongest predictors for risk were: Triple-lumen PICCs. PICCs placed in patients with a history of VTE in the past 30 days. PICCs placed in the setting of active cancer. Derived and internally validated in a cohort of 22,000 patients that received PICCs on medical wards or critical care settings. Extrapolation to dissimilar populations might not yield similar results. A Michigan Risk Score Class I score is not necessarily “low risk” (incidence of DVT ~1%). Not validated in surgical patients or patients undergoing surgery with a PICC. Not validated in pediatric patients (<18 years of age).

Advice

Carefully consider the risks and benefits of using a PICC, especially if the risk of thrombosis is high. Consider alternative devices (e.g. central venous catheters, ports, tunneled catheters) that can be placed in larger veins, if appropriate.

More Information

Interpretation: Michigan Risk Score Risk Class Probability of VTE 0 I 0.9% 1–2 II 1.6% 3–4 III 2.7% ≥5 IV 4.7%