short regulation of blood shugar( NAVYA n GURU.pptx

short regulation of blood shugar

1. Circulatory shock PRESENTED BY – Dr. Navya Vashisth MDS-2023

2. Definition

3. Manifestations of circulatory shock

4. MANIFESTATIONS OF CIRCULATORY SHOCK Whenever cardiac output is decreased, the arterial blood pressure drops down. Low blood pressure produces reflex tachycardia and reflex vasoconstriction. Tachycardia decreases the diastolic period .So, filling of heart reduces leading to decrease in stroke volume and systolic pressure. This decreases pulse pressure below 20 mmhg . Pulse also become feeble. Stagnant hypoxia develops because of decreased velocity of blood flow. Skin becomes pale and cold due to vasoconstriction.

5. Along with hypoxia cyanosis also develops in many parts of the body, particularly earlobes and fingertips. Glomerular filtration rate (GFR) and urinary output are reduced due to fall in blood pressure and constriction of renal blood vessels. Metabolic activities of myocardium are accelerated because of reduced blood flow and increased heart rate. A large amount of lactic acid produced,resulting in acidosis . Acidosis decreases myocardial efficiency and pumping action of heart leading to further reduction in cardiac output. So the blood flow to vital organs is severely affected. Lack of blood flow to the brain tissues produces ischemia resulting in fainting and repairable damage of brain tissues. .Finally the damage of brain tissues and cardiac arrest kill the victim.

6. Stages of circulatory shock First stage or compensated stage Second stage or progressive stage Third stage or irreversible stage

7. COMPENSATED STAGE OF CIRCULATORY SHOCK

8. PROGRESSIVE STAGE OF CIRCULATORY SHOCK

9. IRREVERSIBLE STAGE OF CIRCULATORY SHOCK

10. Shock due to decreased blood volume: hypovolemic shock Shock due to decreased blood volume is called as hypovolemic shock or cold shock. It occurs when there is acute loss of at least 10% to 15% of blood. Loss of blood less than 10% may not produce any significant effect because of immediate compensatory mechanism.

11. Important manifestations of hypovolemic shock Decrease in cardiac output Low blood pressure Thin thready pulse Cold and pale skin Increase in respiratory rate Restlessness or lethargy

12. Hemorrhagic shock Hemorrhagic shock is the shock due to hemorrhage. ACUTE HEMORRHAGE as in the case of accident causes shock. CHRONIC HEMORRHAGE is loss of blood either by internal or external bleeding over a long period of time.

13. Traumatic shock TRAUMA means serious injury or wound caused by some external force. SHOCK caused by trauma is known as traumatic shock. Shock occurs due to the damage of muscles and bone, which is common in battlefields and road accidents. Apart from the loss of blood the blood escapes to the tissues as well.

14. SURGICAL SHOCK Surgical shock is the shock developed during surgical procedures. It may develop due to INTERNAL HEMORRAGE, EXTERNAL HEMORRHAGE and DEHYDRATION that occurs during or after surgical procedure.

15. BURN SHOCK Burn shock is the shock produced by BURN’. In BURNS loss of plasma through burnt surface is more than the loss of whole blood,it decreases the ECF volume and plasma volume, resulting in HEMOCONCENTRATION.This leads to sluggish blood flow, which decreases the cerebral blood flow causing shock.

16. DEHYDRATION SHOCK SHOCK due to dehydration is called as DEHYDRATION SHOCK. DEHYDRATION means decrease in water content of body,it decreases the blood volume resulting in shock.

17. SHOCK DUE TO INCREASED VASCULAR CAPACITY- VASOGENIC SHOCK In case the blood volume is normal, the shock occurs due to inadequate blood supply to the tissues due to increased vascular supply. Capacity of the vascular system increases by extensive dilatation of blood vessels. It is also known as vasogenic or LOW RESISTANCE OR DISTRIBUTIVE SHOCK

18. CAUSES AND TYPES OF VASOGENIC SHOCK Sudden loss of vasomotor tone: Neurogenic shock Anaphylaxis: anaphylactic shock Sepsis: septic shock

19. NEUROGENIC SHOCK NEUROGENIC SHOCK is the type of shock characterized by sudden depression of nervous system due to extensive vasodilatation caused by loss of vasomotor tone. CONDITIONS WHEN THE NEUROGENIC SHOCK DEVELOPS ISCHEMIA OF BRAIN:severe ischemia in medulla depresses the activity of vasomotor centre GENERAL ANESTHESIA SPINAL ANESTHESIA EMOTIONAL CONDITIONS: extreme emotions cause sudden and exaggerated activity of autonomic nervous system, the subject faints due to neurogenic shock.

20. ANAPHYLACTIC SHOCK Anaphylaxis means EXAGGERATED ALLERGIC REACTION to a foreign protein or antigen or any other substance to which the person has been sensitized. SHOCK that develops during ANAPHYLACTIC REACTIONS is called anaphylactic shock. SHOCK occurs because of vasodilatation and sudden fall in blood pressure. It is caused by chemical mediators such as HISTAMINE that are secreted during ANAPHYLACTIC REACTIONS.

21. SEPTIC SHOCK SEPSIS is a pathological condition characterized by the presence of pathogenic organisms or their toxin in blood or tissues, SHOCK developed during sepsis is known as septic shock or BLOOD POISONING. CONDITIONS WHEN SEPTIC SHOCK OCCURS Infection of uterus and the fallopian tube,commonly occurring in ABORTION by instrumentation. Infection of peritoneum Spreading of skin infection due to bacteria like STREPTOCOCCI or STAPHYLOCOCCI

22. SHOCK DUE TO CARDIAC DISEASES – CARDIOGENIC SHOCK CONDITIONS WHEN THE CARDIOGENIC SHOCK OCCURS ARRHYTMIA, particularly those which lead to reduced cardiac output. Decreased activity of myocardium due to ISCHEMIA. Congestive cardiac disease

23. SHOCK DUE TO OBSTRUCTION OF BLOOD FLOW- OBSTRUCTIVE SHOCK Conditions when obstructive shock develops Tumour in myocardium Cardiac tamponade Obstruction of blood vessels in lungs due to EMBOLISM

24. TREATMENT FOR CIRCULATORY SHOCK

25. BLOOD TRANFUSION: Tranfusion of whole blood is done in hypovolemic shock except BURN SHOCK. PLASMA TRANSFUSION:Plasma transfusion is very useful in BURN SHOCK or in the shock where there is more plasma loss. ADMINISTRATION OF PLASMA SUBSTITUTES :Plasma substitute is a solution of a substance that is used for transfusion instead of plasma. Plasma substitutes are used when plasma is not available. Commonly used plasma substitutes PLASMA EXPANDERS( solutions of sugar with high molecular weight such as dextran), such substances do not escape though capillary membrane CONCENTRATED HUMAN SERUM ALBUMIN HYPERTONIC SOLUTIONS which cause drawing of fluid into blood from interstitial space.

26. ADMINISTRATION OF SYMPATHOMIMETIC DRUGS SYMOATHOMIMETIC DRUGS LIKE epinephrine and norepinephrine are useful in NEUROGENIC AND ANAPHYLACTIC SHOCKS, which occur due to vasodilatation.These two drugs restore the blood pressure by vasoconstriction. However these drugs should not be used for longer period as they induce severe myocardial activity. In traumatic and cardiogenic shock DOPAMINE is used. ADMINISTRATION OF GLUCOCORTICOIDS They are administered in serious conditions. increase the glucose metabolism in damaged tissues, prevent further damage to the tissues and increase MYOCARDIAL ACTIVITY.

27. OXYGEN THERAPY IT is given in severe conditions involving REDUCED OXYGENATION OF TISSUES. BY CHANGING THE POSTURE This is the first measure taken in cases of hemorrhagic and neurogenic shock. THE HEAD DOWN POSITION By raising the bed at the foot end ,this increases- VENOUS RETURN,CARDIAC OUTPUT AND CEREBRAL BLOOD FLOW. However this should not be used for longer period as prolonged head down position my affect the ventilation.Its because of effect of increased pressure exerted by abdominal viscera or diaphragm.

28. Short term Regulation of blood pressure Presented by : Dr GURUNATH

29. Int r oduction It is the lateral pressure exerted by the moving column of blood on the vessel wall .

30. COMPONENTS OF SYSTEMIC ARTERIAL B.P.

31. S phygmomanometer Since the blood pressure increases with anxiety, measurements should be made with the patient relaxed and fully at rest.

32. FACTORS AFFECTING ARTERIAL B.P. Age Sex Body built Diurnal variation Exercise Emotions Hereditary Meals Posture

33. REGULATION OF ARTERIAL B.P. The various mechanisms exist within the body to regulate the systemic arterial B.P. Their main aim is to maintain the normal MBP within a narrow range, between 95 to 100 mmHg. The different mechanisms available are: Rapidly acting regulatory mechanisms; Intermediate acting regulatory mechanisms Long-term acting regulatory mechanisms Short term

34. LOCAL REGULATORY MECHANISMS

35. Rapidly acting regulatory mechanism Acts within seconds to minutes. Loose their capability for pressure control after a few hours or days. They are primarily, a circulatory reflex mechanism helping in controlling extreme high or low BP. Get activated in situations like, sudden change in Body posture, Profuse bleeding, etc.

36. Circulatory Reflex Include Baroreceptor reflexes Chemoreceptor reflexes CNS ischaemic response

37. Baroreceptor reflexes Baroreceptor Situated in the carotid sinus and aortic wall. Few receptors are found in all thick arteries of head and neck. They are Mechanoreceptors, that are sensitive to stretching. Also called Pressoreceptors as they respond better to pulsatile pressure. They have spray type nerve endings.

38. Innervated by the Glossopharyngeal and Vagus nerve

39. Mechanism of blood pressure by baroreceptors

40. Chemoreceptor mechanism Responds to change in chemical constituents of blood Peripheral chemoreceptors are situated in carotid body and aortic body These are sensitive to lack of oxygen,excess of co2,hydrogen ions in blood When bp decreases blood flow to receptor decreases These above factors excite the chemoreceptors which send impulses to stimulate vasoconstrictor centre It operates between 40-100mgHg range of MBP Can correct further 2/3 rd of further fall in B.P

41. CNS ischaemia response It operates between 15-50 mmHg It does not operate until bp falls at 50mmHg Fall in arterial bp to 20 -30mmHG CNS ischaemia CO2 accumulation in VMC which stimulate pressor area Tremendous Discharge occurs Thus heart rate and bp increases to maintain normal supply of blood to brain This mechanism thus acts as last Ditch stand to prevent death of a person

42. INTERMEDIATE ACTING REGULATORY MECHANISMS

43. SALIENT FEATURES They begin to act within few minutes and reach full function within few hours These mechanisms remain functional from few days to a month only. They primarily correct any alteration in B.P. by altering the blood volume

44. INTERMEDIATE ACTING REGULATORY MECHANISMS CAPILLARY FLUID SHIFT MECHANISM STRESS RELAXATION AND REVERSE STRESS RELAXATION MECHANISM

45. References Hall JE. Guyton And Hall Textbook Of M e dical Physiolo g y . ELS E VI E R, 13 th In c . editio n Philadelphia; 2016 Jain A K Human Physiology for BDS , 4 th edition , 2010