Venous Thromboembolism

Understanding the Study’s Key Findings

A Danish study published in The BMJ found that mechanical restraint in psychiatric hospitals is linked to a small but statistically significant increase in the short-term risk of venous thromboembolism (VTE), or blood clots. The research followed 24,423 adults admitted to Danish psychiatric hospitals between 2000 and 2022, comparing outcomes for patients subjected to mechanical restraint versus chemical restraint.

Among those exposed to mechanical restraint, the 30-day VTE risk was 3.5 per 1,000 patients, compared to 1.7 per 1,000 for those under chemical restraint. The study estimates that one additional VTE case could occur for every 548 patients subjected to mechanical restraint, though the absolute risk remains low.

Researchers emphasize that while the findings highlight a potential risk, they do not establish causation. The study’s authors note that factors like immobility—common with mechanical restraint—could contribute to VTE, but other unmeasured variables might also play a role.

How Mechanical Restraint Increases VTE Risk

Measuring 3.5 per 1,000 patients, the 30-day VTE risk for those under mechanical restraint is nearly double that of patients receiving chemical restraint. This disparity aligns with existing knowledge that immobility is a key risk factor for blood clots. In psychiatric settings, mechanical restraint—typically involving waist belts or, less frequently, wrist or ankle straps—may limit movement, increasing the likelihood of clot formation.

Experts caution that patients with severe mental illness already face elevated VTE risks due to factors like physical inactivity, smoking, and comorbid conditions. The study adds that mechanical restraint could exacerbate these risks, particularly in the short term.

Why This Matters for Patient Care

The findings underscore the need for balancing patient safety with preventive care in psychiatric hospitals. While mechanical restraint is sometimes necessary to prevent harm, the study suggests that minimizing its use could reduce VTE risk. Researchers recommend integrating VTE prevention strategies, such as early mobilization and anticoagulant therapy, for patients exposed to restraints.

“Mechanical restraint was associated with an elevated risk of VTE,” the study concludes. “These findings highlight the importance of preventive strategies to reduce the risk of VTE in patients exposed to mechanical restraint.”

What’s Next for Research and Policy?

The study’s authors call for further research to confirm these findings and explore interventions that mitigate VTE risk without compromising safety. An accompanying editorial emphasizes that restraint may be a “modifiable risk factor,” but more data is needed to establish baseline VTE rates in psychiatric populations.

Denmark’s comprehensive healthcare data system—covering all psychiatric hospitals—provided the study with a rare level of detail. This approach, the researchers say, strengthens the reliability of their conclusions, even as they acknowledge the limitations of observational studies.

Real-World Implications and Preventive Strategies

Experts also stress the importance of individualized VTE risk assessments. “Patients with a history of blood clots, obesity, or prolonged immobility should be prioritized for preventive measures,” says a statement from the study’s authors. “This includes early ambulation and, when appropriate, low-molecular-weight heparin.”

Did You Know?

FAQ: Answers to Common Questions

What is mechanical restraint?

Mechanical restraint involves using physical devices like waist belts or straps to limit a patient’s movement. It is used in psychiatric hospitals when there is an immediate risk of harm to the patient or others.

How does it increase VTE risk?

Immobility from mechanical restraint can slow blood flow, increasing the likelihood of clot formation. This aligns with broader medical knowledge that prolonged inactivity is a key VTE risk factor.

Are there alternatives to mechanical restraint?

Yes. Non-restraint approaches, such as de-escalation techniques, environmental adjustments, and staff training, are increasingly used to manage behavioral crises without physical restraints.

What should hospitals do now?

Hospitals should review their restraint policies, prioritize preventive VTE measures for at-risk patients, and invest in staff training to reduce reliance on mechanical restraint.

Pro Tips for Healthcare Professionals

Call to Action

Healthcare professionals, policymakers, and patient advocates are encouraged to review the The BMJ study and its implications for psychiatric care. Share your insights in the comments below or explore our related articles on mental health safety and VTE prevention. Stay informed—your knowledge could save lives.