Haemostasis Flashcards
What would a risk assessment prior to a tooth extraction involve?
- careful planning
- thorough analysis of medical history
What does the process of haemostasis involve?
- vasoconstriction
- platelet plug formation
- coagualation cascade/network
Clot formation is a dynamic process. It involves a balance between what systems?
haemostatic and fibrinolytic systems
When does fibrinolysis occur?
When the plasminogen precursor is activated and becomes plasmin
Plasmin is then able to digest the fibrin threads in the clot
The majority of clotting factors are produced in the …
liver
Platelets are produced in the …
red bone marrow
Problems relating to clotting factors and platelets are either ________ or ________
acquired or congenital
Give an example of a congenital clotting factor deficiency
Haemophilia A (factor VIII deficiency)
State the 3 types of post extraction haemorrhages
- primary haemorrhage
- reactionary haemorrhage
- secondary haemorrhage
What is a primary haemorrhage?
this is bleeding that occurs at the time of surgery
What is reactionary haemorrhage?
this is bleeding that occurs 2-3 hours after the procedure as a result of cessation of vasoconstriction
What is a secondary haemorrhage?
this is bleeding that occurs up to 14 days after the surgery.
What is the most likely cause of a secondary haemorrhage?
infection
Haemorrhages can also be classified according to the site affected. Give examples of such sites
- soft tissue
- bone
- vascular
The use of haemostatic agents and equipment is not limited to managing post-extraction haemorrhages. Give examples of other invasive procedures where haemostatic agents/equipment are useful
- non surgical periodontal therapy
- periodontal surgery
- pulpotomy
- preparation of teeth for indirect restorations
Briefly describe immediate post extraction management and why it is important
- once a tooth has been removed, pressure shoud be placed on the buccal and lingual/palatal sufaces of the alveolus around the socket- this is referred to as **digitalised pressure **
- this immediate bucco-lingual pressure reduces the dead space of the wound and is the first step to gain haemostasis
What is the result of the extraction of a tooth via the intra-alveolar approach?
expansion of the alveolus aorund the roots of a tooth
Intra-alveolar extraction is a forceps extraction (not a surgical extraction!)
Post-operatively, how would you manage an extraction site with an opposing edentulous area? Why would you go about it this way?
use finger pressure on the gauze for several minutes
this is because biting together following gauze placement may not apply enough firm pressure
What is the duration of time for the formation of granulation tissue following an extraction?
24 hours
Give examples of clotting factor deficiencies
- haemophilia A (factor VIII)
- haemophilia B (factor IX)
- Von willibrand disease
- vitamin K deficiency (Factor II, VII, IX, X)
- Acquired liver disease- hepatitis/ cirrhosis
Platelet deficiencies such as thrombocytopenia can be either ________ or ___________
idiopathic
or
drug induced (antiplatelet therapy)
Give examples of vascular anomalies that put patients at high risk of post extraction haemorrhage
- atriovenous malformation
- hereditary haemorrhagic telangiecstasia
- collagen disorders
Failure to give a patient clear post operative instructions for the management of the socket can lead to ____________ haemorrhage
secondary
Why is it important to provide a concise instruction leaftlet as well as verbal POI?
- patients may not be able to recall a long list of instruction following extraction
Providing a leaflet without comprehensive verbal instructions is acceptable practice. True or fale
false
What clinical scenarios is it acceptable for a clinician to give after care instructions at a previous appointment or pre-operatively?
patients having treatment under IV or inhalation sedation who may have their ability to retain information significantly reduced
In the presence of infection, granulation tissue may form at the base of the socket. How does the presence of granulation tissue increase the risk of bleeding ?
- impairs clotting
- granulation tissue (macrophage cytokines such as VEGF encourage angiogenesis as a result there is an abundance of fragile blood vessels - prone to haemorrhage)
What size and shape of needle is useful for suturing intra-oral wounds
3.0 suture
1/2 circle curved needle
How long does polygactin (vicryl) offer wound support?
7-10 days
What is in a dental clinicians armanentarium for a post-extraction haemorrhage?
- sterile gauze (pressure pack)
- suction
- suture kit (needle holders, tissue forceps, suture material and needle)
- haemostatic gauze
- bone wax
- astringent solution e.g. ferric sulphate
- 5% tranexamic acid mouthwash
- cautery
- systemic monitoring equipment- blood pressure, heart rate, pulse oximeter
Give examples of haemostatic agents that are available to a dental practitioner
- tranexamic acid
- ferric sulphate
- silver nitrate
List the POI following a dental extraction
Do not:
* rinse your mouth on the day of extraction as it may dislodge the clot
* drink alcohol/hot drinks at least 24 hours; may increase blood pressure and induce hyperaemia
* smoke or use tobacco products for at least 24 hours (causes vasoconstriction and can increase dry socket)
* chew food for 4 hours, avoid hard foods as they may disturb clot
* carry out physical activity (increased blood pressure
Do:
* sip lukewarm drinks carefully (helps avoid clot removal by washing out socket)
* bite on gauze for 10 minutes if area bleeds, sitting upright
* salt water rinces or CHX (0.2%) mouthwash after 24 hours. Continue regular mouthwash use over following weeks especially after meals
* clean teeth as normal, avoiding area of surgery for 24 hours
What are directions of use for 5% tranexamic acid mouthwash?
use as a rinse 4x daily for two days post-operatively
to prevent fibrinolysis
What are the first line management options for soft tissue haemorrhages ?
- sutures
- haemostatic gauze
Ferric sulphate is commonly used an ____________ solution in dentistry
astringent solution (15.5%)
Give instances where ferric sulphate is commonly used
- gingival retraction techniques for impressions for crown and bridge work
- haemostatic agent for pulpotomy
In what form is silver nitrate available?
It is available in the form of pencil which contains 95% silver nitrate
When are silver nitrate pencils made use of ? Give specific examples of such instances
to aid haemostasis in areas where suturing or finger pressure is not possible
mucosal biopsy taken from hard palate or retromolar pad
Silver nitrate is a powerful _______ agent
cauterizing agent
burning flesh in order to control bleeding
How is silver nitrate deactivated?
after a few minutes silver nitrate should be de-activated by genetly swabbing the area with saline solution to avoid damage to surrouding structures
How can bleeding from within the socket be arrested in most cases?
it can be arrested by inserting a pack
How can you manage a bony haemorrhage?
cancellous bone can be burnished with a flat plastic instrument or mitchells trimmer to help compress the bone in that area
The use of haemostatic gauze/dressing along with the placement of suture is recommended for patients at high risk of post operative haemorrhage. Give examples of resorbable haemostatic dressing materials
- surgicel
- haemocollagen
- Gelfoam
Surgicel is …
oxidised regenerated cellulose
Haemocollagen is a ________ sponge
collagen
Gelfoam is a ________ sponge
gelatin
Give examples of non-resorbable haemostatic dressing
Kaltostat
What does bone wax consist of?
- beeswax
- paraffin
- softening agent
What is the main use of bone wax?
it can be used to control bleeding in cancellous bone
it is placed into spaces within the bone
How does surgicel facilitate haemostasis ?
it forms a gelatinous mass upon saturation with blood which leads to the formation of a stable clot
How does bone wax facilitate haemostasis?
the pressure provided facilitates haemostasis
What are the caveats of bone wax usage?
- non-resorbable and thus the host may treat it as a foreign body
- complete removal of bone wax is difficult and thus it often remains in situ
Wax placement is often followed by …
placement of haemostatic gauze and a suture to maintain pressure on the socket
What type of haemorrhage causes the most distress to a patient?
vascular haemorrhage
What sort of repair may be required for a large vessel haemorrhage?
ligation
(tying up an artery)
What sort of repair may be carried our for smaller vessels?
cauterization
(burn)
What is electrocautery?
this is the process of sealing the exposed end of a vessel with heat conduction
When is systemic monitoring of particular importance?
when dealing with a secondary haemorrhage
How should a patients blood pressure be monitored?
sphygmomanometer
How is should patients heart rate be monitored?
- manually
- pulse oximeter
When should a patient be referred to A&E following an extraction? What treatment should these patient receive ?
- if it is not possible to arrest haemorrhage
- With the following readings:
- diastolic BP: consistently <60 in a short monitoring period
- systolic BP: consistently <100 in a short monitoring period
- heart rate raised- 100bpm - tachycardic
they should receive fluid replacement as these are the signs of hypovolaemic shock
What is the quickest route to successful management of a haemorrhage?
the correct diagnosis
Outline the management of a vascular haemorrhage ?
- localise vessel
- apply pressure
- may require electrocautery or ligating
- haemostatic gauze
- suture
Outline the management of a soft tissue haemorrhage ?
- haemostatic gauze
- suture
- chemical agents if appropriate
Outline the management of a bony haemorrhage ?
- identify site of haemorrhage
- place haemostatic gauze then suture
- burnish if possible and or insert bone wax, pack and suture
