local hemostatic agents(2)
TRANSCRIPT
Surgical Secondary Hemostasis in Wound Healing
Dr. Milan D Choksey
"An area of increasing concern is lethal hemorrhage from sites that are not suitable for application of
tourniquets or compression dressings."
Hasan B. Alam. "Hemorrhage control in the battlefield: Role of new hemostatic agents." Military Medicine, 170(1):63-69.
Hemostasis
Biology of Hemostasis
Injury to a vessel
Platelet factors Vascular factors Plasma/blood factors
Stable Hemostatic clot
Fibrin clotVasoconstrictionPlatelet plug
Synergy of Factors contributing to normal hemostasis
Phases of Hemostasis
• Primary hemostasis – Arteriolar vasoconstriction – Formation of platelet plug
• Secondary hemostasis – Activation of coagulation cascade – Formation of permanent fibrin plug
Types of bleeding during Surgery
• Arterial bleeding: – Pulsating
• Venous bleeding – Oozes
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Factors influencing Surgical bleeding
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Adverse effects of Surgical bleeding
• Visual obstruction of the surgical field
• Need for blood transfusions
• Reduction in core temperature
• Thrombocytopenia
• Hypovolemic shock
• Economic consequences
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Characteristics of an Ideal hemostatic agents for prehospital/battlefield use:
(1) capability to stop large vessel arterial and venous bleeding within minutes of application when applied to an actively bleeding wound through a pool of blood;
(2) no requirement for mixing or pre-application preparation;
(3) simplicity of application by wounded victim, buddy, or medic;
(4) light weight and durable; (5) long shelf life in extreme environments;(6) safe to use with no risk of injury to tissues or
transmission of infection;(7) cost-effective
Methods of HemostasisMechanical methods . Direct pressure
. Fabric pads/sponges/gauzes
. Sutures/staples/ligating clips
Thermal/energy based methods . Electrosurgery . Monopolar . Bipolar . Bipolar vessel sealing device . Argon enhanced coagulation . Ultrasonic device . Laser
Chemical methods . Pharmacological agents
. Epinephrine
. Vitamin K
. Protamine
. Desmopressin
. Lysine analogues
. rFVIIa
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
. Topical hemostatic agents . Passive (mechanical) agents
. Active agents
. Collagen based agents
. Cellulose
. Gelatin
. Polysaccharide spheres
. Thrombin products
. Others . Flowables . Sealants . Fibrin sealants . Polyethylene glycol (PEG) polymers . Albumin and glutaraldehyde . Cyano-acrylate
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Mechanical methods
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Thermal/energy based methods
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Monopolar Electrosurgical Unit
Bipolar Electrosurgical Unit
Bipolar Vessel Sealing device
Chemical methods – pharmacological agents
Chemical agents enhance the natural coagulative mechanisms
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Historical background of Chemical hemostatic agents
• Hippocrates used caustics to achieve hemostasis.
• At the end of the eighteenth century, Carnot introduced gelatin.
• In 1886 Horsley developed a mixture of beeswax, salicylic acid, and almond oil, thus leaving his legacy of “antiseptic wax.”
• Oxidized cellulose(OC) in 1942
• Oxidized Regenerated Cellulose (ORC) was developed in 1960
• Gelatin foam(GF) in 1945
• Microfibrillar collagen (MFC) was developed in 1970 by Hait
• Chitosan based agents was approved by FDA at 2003
• The newest mineral based agent has been introduced by US Army Institute of Surgical Research in 2007
• A Plant extract agents was registered in Turkey in 2007
Topical hemostatic agents
• Two primary categories: passive and active
• Two more categories: flowables & sealants
Passive Active
Act passively thru contact with bleeding sites and promotion of platelet aggregation
Acts biologically on the clotting cascade
Eg collagens, cellulose, gelatins and polysacchride spheres
Eg thrombin and products in which thrombin is combined with a passive agent
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Topical agents – passive Provides a physical, lattice like matrix that adheres to bleeding site
Matrix activates the extrinsic clotting pathway
Platelets aggregate and form a clot
Passive agents rely on fibrin production and hence can be used only in a patient with intact coagulation cascade
Passive agents can absorb several times its weight in fluid. However, this expansion of the agent can cause complications like compression of surrounding tissues.
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Collagen based products
Activated on contact with bleeding. Provide stable matrix for clot formation, enhance platelet aggregation, degranulation and release of clotting factors
Derived from either bovine tendon or bovine dermal collagen
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Topical agents – active Have biological activity
Participate directly at the end of coagulation cascade
Stimulate fibrinogen at the bleeding site to produce a clot
Thrombin acts at the end of the clotting cascade, action of agent is not affected by clotting factor deficiencies or platelets malfunction. Can also be given to patients receiving anti-platelets/anti-coagulation
Active topical agents provide hemostasis within 10 minutes and they are more effective in controlling bleeding than passive agents
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Thrombin products
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Flowable hemostatic agents
• Combine passive and active hemostatic agents into a single application product
• Work by blocking blood flow & actively converting fibrinogen into fibrin
• Two types of products: – Absorbable bovine gelatin + pooled human thrombin – Absorbable porcine gelatin + either of the 3 thrombin types
• Both the products do not contain fibrinogen. Hence direct contact with blood is necessary
• Both products are indicated for all types of surgeries except ophthalmic surgeries
• AEs: anemia, arrhythmia, arterial thrombosis, atelectasis, atrial fibrillation, hemorrhage, infection, pleural effusion, right heart failure
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Sealants Sealants work by forming a barrier that is impervious to the flow of most liquids
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Polyethylene glycol polymers
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Albumin-glutaraldehyde
• Contains 10% glutaraldehyde sol and 45% bovine serum albumin
• Glutaraldehyde cross-links the residual proteins in albumin to cell proteins at wound site and forms a tough scaffold to which clot can adhere
• Commonly used for sealing holes around suture or staple lines in complex CV procedures and in peripheral vascular procedures
• AEs: tissue injury, muscle necrosis, emboli, delayed pseudoaneurysm formation, sensitivity to glutaraldehyde
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Cyano-acrylates
• Consists of 2 cyanoacrylate monomers – 2-octyl cyanoacrylate– Butyl lactoyl cyanoacrylate
• Product to be used as a sealant and not as a substitute for sutures, staples, or other methods of mechanical closure
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Key considerations in the selection of topical agent
• Rapidly and effectively control bleeding • Effectively contact the bleeding surface • Work reliably • Be handled easily • Be prepared easily • Be available in multiple delivery options • Be compatible with patient’s physiology • Be safely used • Be cost effective
Adapted with permission from: Samudrala S. Topical hemostatic agents in surgery: a surgeon’s perspective. AORN J. 2008;88(3): S2-S11
Thank you