Dental treatment for patients with bleeding disorders

Normal clotting of blood, or haemostasis, following dental treatment involves the complex interaction of blood vessels, platelets, clotting factors and factors which then case breakdown of blood clots. This article describes the normal clotting process and the common causes of and practical management of patients with bleeding problems.

The aim of normal haemostasis, outlined in Figure 1, is to stop blood loss from damaged vessels by the formation of a fibrin reinforced blood clot. This occurs via three phases:

Figure 1.Normal Haemostasis

Vessel wall contraction

Platelet aggregation

Blood coagulation—formation of a fibrin clot.

Following blood vessel injury, smooth muscle in the vessel wall contracts to decrease blood flow from the area. Platelets then aggregate in the area, sticking to exposed collagen in the damaged blood vessel forming a platelet plug. Proteins in the blood plasma, known as clotting factors, respond in a complex cascade to form fibrin strands which strengthen the platelet plug to form a blood clot. This coagulation cascade is made up of three stages, the intrinsic pathway, extrinsic pathway and common pathway (Figure 2).