HEMOSTASISDr. Imran Aslam Assistant ProfessorNorth Surgical Ward

INTRODUCTION Hemostasis is the process of forming clots

in the walls of damaged blood vessels and preventing blood loss while maintaining blood in the fluid state within the vascular system.

VIRCHOW’S TRIAD Coagulation is combination of1. Stasis of blood2. Endothelial injury3. Hypercoagulability

EVENTS IN HEMOSTASIS Hemostasis means prevention of ‘Blood Loss’. Hemostasis is achieved by

several mechanism:- Vascular constriction Formation of platelet plug Formation of blood clot Growth of fibrous tissue into the clot.

1.VASCULAR CONSTRICTION The contraction results from:- Local myogenic spasms Local autacoid factors Nervous reflexes

Platelets release, Thromboxane-A2 which is responsible for vasoconstriction of smaller vessels.

The more severely a vessel is traumatized, the greater the degree of vascular spasm.

2.FORMATION OF PLATELET PLUG MECHANISM OF PLATELET

PLUG Platelet adhesion Platelet activation Platelet aggregation Formation of temporary

hemostatic plug

3.BLOOD COAGULATION IN RUPTURED VESSEL Third mechanism for hemostasis is formation of blood clot Clot begins to develop- severe trauma-15 to 20 sec minor trauma-1 to 2 min

COAGULATION PATHWAYS These mechanisms are set into play by:- Trauma to the vascular wall and the adjacent tissues Contact of the blood with damaged endothelial cells

a) Extrinsic pathway for initiating blood clotting b) Intrinsic pathway for initiating blood clotting

EXTRINSIC PATHWAY FOR INITIATING BLOOD CLOTTING

INTRINSIC PATHWAY

FORMATION OF FIBRIN NETWORK In response to rupture of the vessel or damage to the

blood itself-formation of prothrombin activatorProthrombin activator catalyzes conversion of

prothrombin to thrombinThrombin catalyzes fibrinogen into fibrin fibers.

CONVERSION OF PROTHROMBIN TO THROMBIN AND THEN FIBRINOGEN INTO FIBRIN

BLOOD CLOT The clot is a meshwork Fibrin fibers also adhere to damaged surfaces of blood vessels. As the clot contracts, the edges are further pulled together, contributing

ultimate state of Hemostasis.

CONVERSION OF FIBRINOGEN TO FIBRIN-FORMATION OF THE CLOT

FIBRINOGEN

ACTION OF THROMBIN ON FIBRINOGEN TO FORM FIBRIN

BLOOD CLOT

CLOT RETRACTION-SERUM

CLOTTING PROCESS IN A TRAUMATIZED BLOOD VESSEL

METHODS OF HAEMOSTASIS

METHODS OF HAEMOSTASIS

MECHANICAL HEMOSTASISDirect pressure

Gauze pack

Suture and ligation

Staples

DIRECT PRESSURE First choice to control bleeding Fast and simplest Small Arterial bleeding Venous bleeding 15-20 sec Not recommended in major artery and veins.

FABRIC PADS/GAUZE/SPONGE Used with direct pressure It is used in - only pressure is not an

option -systemic bleeding due

to infection, trauma, massive blood loss, and platelet dysfunction.

SUTURE/STAPLES/LIGATING CLIPS Suture – used in major arteries and veins Ligation of facial artery, lingual artery, and external carotid artery

TYPES OF LIGATIONStick Tie: Also called as transfixation. Used for High Blood pressure Proximal part of the vesselsRegular Tie Used for Distal part of the vessels Also used for tubectomy .

Staples- sterile and disposable titanium staples

Ligating clips- quick and easy decrease foreign body reaction various size

USE OF HEMOSTATS Hemostats (Mosquito and Artery) are designed to catch bleeders. Can be straight or curved.

BONE WAX Is a mixture of Beeswax (70%) and Vaseline (30%). It is a non-absorbable material , becoming soft and malleable in the hand

when warmed Its Hemostatic effect is based on physical rather than biochemical

properties. It has been used in bone surgeries

TRANS CATHETER ARTERIAL EMBOLIZATION -Restricts tumors blood supply . -Arterial embolization preferentially interrupts tumors blood supply and

stalls growth until neovascularization - Used to control bleeding in Hemangiomas

THERMAL ENERGY METHOD

METHODS: Heat (Cautery) Electro cautery: it is the use of high frequency alternating current for

cutting, coagulating, dessication or fulgurating tissue in both open and laparoscopic procedure

monopolar electro surgery bipolar electro surgery bipolar electrosurgery vessel sealing technology argon enhanced coagulation technology Ultrasonic device Lasers

MONOPOLAR ELECTRO CAUTRY Most frequently used Two electodes- active (the pencil) - dispersive Modes - coagulation mode - cutting mode - blend mode Current flows through the patient from electrode (active) to electrode

(dispersive)

BIPOLAR ELECTRO SURGERY Current does not flow through the patient’s body Lower voltage Indicated in limited thermal spread Delicate tissue, small anatomical tissue Safe for implanted medical devices such as pacemaker, internal

cardioconverter fibrillator etc.

CHEMICAL METHODS

Pharmacological agents Topical haemostatic agent Passive active

PHARMACOLOGICAL AGENTS Sterile haemocoagulase solution Epinephrine Vitamin k Protamine Desmopressin Lysin analogs Etamsylate

EPINEPHRINE Causes direct vasoconstriction Can be applied topically and can be injected with LA Prolong analgesic effect Reduces bleeding during surgery Topical - The drug is applied with the help of gauze pack in concentration of

1:1000 over a oozing It is also injected along with local anesthetics in concentration of 1:80,000

and 1:2,00,000.

VITAMIN K Plays important role in coagulation process Helps in production of fibrinogen and prothrombin in liver Route- orally and IV(slow) IM and subcutaneous is not recommended because irratic absorption Dose- Males: 120 mcg/day PO Females: 90 mcg/day PO  5-10 mg IV (dilute in 50 mL IV fluid and infuse over 20 min

PROTAMINE Reverse heparin anticoagulation activity Adverse effect- anaphylaxis, acute pulmonary vasoconstriction, right

ventricular failure Contraindication -diabetic -pt undergone vasectomy -drug allergy -previous protamine exposure Dose -1.0 -to- 1.5 mg protamine sulfate IV for every 100 IU of active

heparin

LYSINE ANALOGUESTranexamic acid- loading dose 2-7gm Follwed by 20-250 mg hourly Total dose of 3-10gm Oral dose; 500 mg 6-8 hrly Children; 1.25g/5 ml of syrup Inj- 0.5-1g slow i.v infusion TID

TOPICAL HAEMOSTATIC AGENTS Passive- collagen based product - oxidised regenerated cellulose - gelatine

Active haemostat - thrombin product - pooled human plasma thrombin - recombinant thrombin