hemostasis and methods to control bleeding
TRANSCRIPT
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