by Payal Gadhawe and Humagauri Pimpre
T.Y.B.Sc Department of Biotechnology DES Fergusson College, Pune. For BTH3507
Blog Category: Hematology
When we pick up a newspaper in morning it is certain to find atleast one case of road accident . In most of the road accidents it is found that damage is caused to the soft tissues of the body, tissues that connect and support other tissues and organs of the body. Have you ever wondered why first 60 minutes just after the occurrence of any trauma during accident are considered as 'Golden Hour' to treat that trauma ? Let's not confuse trauma with distressing/disturbing experience. Trauma here signifies physical injury which includes wound, broken bones, damage to tissue. The tissue damage breaks blood vessel, resulting into the release of blood and after series of event results into inflammation of damaged tissue.
Have you observed how minor injury like cutting a finger while chopping vegetables or a small wound on the elbow , initially causes tremendous bleeding and after a week or too it completely recovers itself. How does this happen ? Answer to this is simple recovery involves a complex process. Wound healing involves series of process starting from hemostasis, inflammation, proliferation and remolding phase.When outer injury occurs ,two layers of skin get damaged ( epidermis and dermis) disrupting underlying blood vessels causing bleeding.
Hemostasis is the process by which clots formed in the wall of damaged blood vessels and prevent blood loss and maintain blood in fluid state within the vascular system. Hemostasis tightly regulate three main processes : 1) Vascular spasm, 2) Platelet plug formation3) Blood coagulation.
In vascular spasm the injured blood vessel contracts (to reduce bleeding )this is triggered by chemicals called endothelins (released by vessel lining cell and as response to pain receptors). In Platelet plug formation, Platelets stick to form plug at the damaged endothelium temporarily sealing punctured blood vessel. Activated platelets release factors to stimulate futher platelet activation.Platelets adhere to the collagen fibre in vessel wall by becoming adhesive and filamentous due to stimulus of Von willebrand factor.
Coagulation is a sophisticated process which is characterized as a cascade , with ultimate aim of fibrin formation. This cascade is activated by two pathway, the extrinsic and intrinsic which merge into a final common pathway. 12 different factors are involved in these pathway. Factor VI is identical to V(so it has been scratched out). Most clotting factor are synthesized in liver except factor IV and VIII.
Extrinsic pathway( Tissue factor pathway ): Occurs quickly and triggered by damage to tissue. The damaged cells release factor III which further activates factor VII to VIIa and factor III and VIIa form enzyme complex(III.VIIa) This complex further enters in common pathway by activating X to Xa.
Intrinsic pathway ( contact activation pathway) :It is longer and complex process and triggered by trauma inside vascular system. Pathway begins with activation of factor XII, which is activated by negatively charged molecule. Activated factor XIIa further activates XI to XIa and factor XIa in turn activates factor IX to IXa which combines with factor VIIIa to form a complex which in turn activates factor X and enter to common pathway.
Common pathway : Both intrinsic and extrinsic pathway merge to produced common pathway. Factor X is activated to Xa. Factor Xa requires factor Va as a cofactor to activate prothrombin to thrombin ( factor IIa ). Factor IIa activate fibrinogen to fibrin.Fibrin subunits come together to form fibrin strand. Factor XIII get activate to XIIIa which stabilize fibrin mesh. This common pathway is regulated by positive feedback mechanism. Activated factor V and II activates factor II and V respectively. To restore normal blood flow as the vessel heals the clot must be dissolved which occurs through fibrinolysis the process by which gradual degradation of clot take place.
Moving to major traumatic injuries like the one caused during accident ,the recovery time are often much longer and vary depending on number of factors (age,medical history,other injuries). Major tissue injuries are needed to be assessed and treated immediately.
Soft tissue injuries : Tissue injuries take longer time to heal.
Common soft tissue injuries are strains, sprains, tendinitis. A bruise is caused during a soft tissue injury which is a sign of bleeding from internal soft tissue and is followed by inflammation which starts within an hour or two after injury.
Inflammation is followed by proliferation, forming scar tissues to repair injury. The process start around 24 - 48 hours and go far several month depending upon severity. Even after the previous processes the soft injury is not mostly fully recovered. It takes around 2-3 weeks to remodel the raw scar to get original form of tissue. For less severe simple method like RICE is performed i.e. rest, ice, compression, and elevation. Depending on the severity of soft tissue injury it is assessed and treated.
GOLDEN HOUR:A LIFE GIVER
Soft tissue injuries and different traumatic injuries caused during accident when assessed and treated within the golden hour it increases the chances of survival. Unfortunately, only 20% of accident cases in India make up to hospital within golden hour.
People’s careless behaviour is one of the main reason for increasing accident cases day-by-day. It’s important to follow all prevention measures to prevent any traumatic injury during accident. This can be only achieved by commitment and co-operation between management, safety programs, safety culture and accountability.
REFRENCE:
1) Pruna R, Artells R. New Tendencies in Risk Factors for Soft Tissue Injuries: Genetic Biomakers. International Journal of Orthopaedics 2015; 2(3): 307-311
2) Shrestha SK. Simple Coagulation Cascade with Mnemonics [Internet]. Epomedicine; 2017 Jan 17 [cited 2020 Aug 30].
3) Kundavaram Paul Prabhakar Abhilash, A. Sivanandan. Early management of trauma: The golden hour. 2020 Jan 25 http://www.researchgate.net/publication/338999083_Early_management_of_trauma_The_golden_hour
4) Colman RW et al, Hemostasis and thrombosis: Basic Principles and Clinical Practice. 2007 Oct. http://www.ahajournals.org/doi/10.1161/ATVBAHA.107.155952
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