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Types and treatment of shock

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Types and treatment of shock

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Types and treatment of shock

  1. 1. In the name of Allah,In the name of Allah, the most Beneficent,the most Beneficent, the most Mercifulthe most Merciful
  2. 2. 2
  3. 3. ShockShock  The word shock is used differently by theThe word shock is used differently by the medicalmedical communitycommunity and the general public. byand the general public. by the public is an intense emotional reaction to athe public is an intense emotional reaction to a stressful situation or bad news.stressful situation or bad news.
  4. 4.  Medically, shock is defined as a condition whereMedically, shock is defined as a condition where the tissues in the body don't receive enoughthe tissues in the body don't receive enough oxygen and nutrients to allow the cells tooxygen and nutrients to allow the cells to function. This ultimately leads to cellular death,function. This ultimately leads to cellular death, progressing to organ failure, and finally, ifprogressing to organ failure, and finally, if untreated, whole body failure and death.untreated, whole body failure and death.
  5. 5. TypesTypes Hinshaw and Cox classificationHinshaw and Cox classification It names four types of shock:It names four types of shock: Hypovolemic,Hypovolemic, Cardiogenic,Cardiogenic, DistributiveDistributive Obstructive shockObstructive shock In many patients, shock is aIn many patients, shock is a combination of two or more ofcombination of two or more of these four types of shockthese four types of shock
  6. 6. Stages of ShockStages of Shock  shock is divided into the following three major stages:shock is divided into the following three major stages:  AA nonprogressive stagenonprogressive stage (sometimes called the(sometimes called the compensated stagecompensated stage), in which the normal circulatory), in which the normal circulatory compensatory mechanisms eventually cause fullcompensatory mechanisms eventually cause full recovery without help from outside therapy.recovery without help from outside therapy.  AA progressive stage,progressive stage, in which, without therapy, thein which, without therapy, the shock becomes steadily worse until death.shock becomes steadily worse until death.  AnAn irreversible stage,irreversible stage, in which the shock hasin which the shock has progressed to such an extent that all forms of knownprogressed to such an extent that all forms of known therapy are inadequate to save the person's life, eventherapy are inadequate to save the person's life, even though, forthough, for
  7. 7. Circulatory ShockCirculatory Shock  Circulatory shockCirculatory shock means generalizedmeans generalized inadequate blood flow through theinadequate blood flow through the body, to the extent that the bodybody, to the extent that the body tissues are damaged because of tootissues are damaged because of too little flow, especially because of toolittle flow, especially because of too little oxygen and other nutrientslittle oxygen and other nutrients delivered to the tissue cells.delivered to the tissue cells.
  8. 8. Hypovolemic shockHypovolemic shock  HypovolemiaHypovolemia means diminished bloodmeans diminished blood volume. This is the most commonvolume. This is the most common type of shock and based ontype of shock and based on insufficient circulatinginsufficient circulating volumevolume..  Its primary cause is loss of fluid fromIts primary cause is loss of fluid from thethe circulationcirculation (most often "(most often " hemorrhagichemorrhagic shock"). Causes mayshock"). Causes may include internal bleeding,include internal bleeding, traumatic bleedingtraumatic bleeding, or severe, or severe burnsburns..
  9. 9. Other causesOther causes Hypovolemic shockHypovolemic shock  GastroenteritisGastroenteritis can cause significant water loss fromcan cause significant water loss from vomitingvomiting andand diarrheadiarrhea, and is a common cause of death, and is a common cause of death in third world countries.in third world countries.  Heat exhaustion and heat strokeHeat exhaustion and heat stroke is caused by excessiveis caused by excessive water loss throughwater loss through sweatingsweating as the body tries to coolas the body tries to cool itself.itself.  Patients withPatients with infectionsinfections can lose significant amounts ofcan lose significant amounts of water from sweating. People inwater from sweating. People in diabetic ketoacidosisdiabetic ketoacidosis lose significant water because of because of elevatedlose significant water because of because of elevated blood sugars.blood sugars.
  10. 10.  Intestinal obstructionIntestinal obstruction is often a cause ofis often a cause of severely reduced plasma volume.severely reduced plasma volume. Distention of the intestine in intestinalDistention of the intestine in intestinal obstruction partly blocks venous bloodobstruction partly blocks venous blood flow in the intestinal walls, which increasesflow in the intestinal walls, which increases intestinal capillary pressure. This in turnintestinal capillary pressure. This in turn causes fluid to leak from the capillaries intocauses fluid to leak from the capillaries into the intestinal walls and also into thethe intestinal walls and also into the intestinal lumen. Because the lost fluid hasintestinal lumen. Because the lost fluid has a high protein content, the result is reduceda high protein content, the result is reduced total blood plasma protein as well astotal blood plasma protein as well as reduced plasma volume.reduced plasma volume.
  11. 11. In almost all patients who have severe burns or other denuding conditions of the skin, so much plasma is lost through the denuded skin areas that the plasma volume becomes markedly reduced. The hypovolemic shock that results from plasma loss has almost the same characteristics as the shock caused by hemorrhage, except for one additional complicating factor: the blood viscosity increases greatly as a result of increased red blood cell concentration in the remaining blood, and this exacerbates the sluggishness of blood flow.
  12. 12. Cardiogenic shockCardiogenic shock  This type of shock is caused by the failure of the heartThis type of shock is caused by the failure of the heart to pump effectively. This can be due to damage to theto pump effectively. This can be due to damage to the heart muscle, most often from a largeheart muscle, most often from a large myocardial infarctionmyocardial infarction..  Other causes of cardiogenic shock includeOther causes of cardiogenic shock include arrhythmiasarrhythmias,, cardiomyopathycardiomyopathy,, congestive heart failurecongestive heart failure (CHF), or(CHF), or cardiac valvecardiac valve problems.problems.
  13. 13. YouTube - Atrial Fibrillation - What Is Atrial Fibrillation Video - Ab ouTube - Cardiac Arrhythmia.flv
  14. 14. End Result of Circulatory ShockEnd Result of Circulatory Shock  the shock itself breeds more shock.the shock itself breeds more shock. That is, the inadequateThat is, the inadequate blood flow causes the body tissues to beginblood flow causes the body tissues to begin deteriorating, including the heart and circulatory systemdeteriorating, including the heart and circulatory system itself. This causes an even greater decrease in cardiacitself. This causes an even greater decrease in cardiac output, and a vicious circle ensues, with progressivelyoutput, and a vicious circle ensues, with progressively increasing circulatory shock, less adequate tissueincreasing circulatory shock, less adequate tissue perfusion, more shock, and so forth until death. It isperfusion, more shock, and so forth until death. It is with this late stage of circulatory shock that we arewith this late stage of circulatory shock that we are especially concerned, because appropriate physiologicespecially concerned, because appropriate physiologic treatment can often reverse the rapid slide to deathtreatment can often reverse the rapid slide to death
  15. 15. YouTube - Cardiac Arrhythmia.flv YouTube - Myocardial Infarction_1.flv YouTube - Cardiomyopathy_1.flv
  16. 16.  Sympathetic Reflex Compensations inSympathetic Reflex Compensations in ShockShock  Value of the Sympathetic Nervous Reflexes.Value of the Sympathetic Nervous Reflexes.  15 to 20 per cent15 to 20 per cent  30 to 40 per cent30 to 40 per cent  Protection of Coronary and Cerebral BloodProtection of Coronary and Cerebral Blood Flow by the Reflexes.Flow by the Reflexes.
  17. 17. Distributive shockDistributive shock  As in hypovolaemic shock there is anAs in hypovolaemic shock there is an insufficient intravascular volume of blood. Thisinsufficient intravascular volume of blood. This form of "relative" hypovolaemia is the result ofform of "relative" hypovolaemia is the result of dilation of blood vessels which diminishesdilation of blood vessels which diminishes systemic vascular resistancesystemic vascular resistance..
  18. 18. Septic shockSeptic shock  Caused by an overwhelming systemic infectionCaused by an overwhelming systemic infection resulting inresulting in vasodilationvasodilation leading to hypotension.leading to hypotension.
  19. 19. Anaphylactic shockAnaphylactic shock  Caused by a severeCaused by a severe anaphylactic reactionanaphylactic reaction to anto an allergenallergen,, antigenantigen,, drugdrug or foreign proteinor foreign protein causing the release ofcausing the release of histaminehistamine whichwhich causes widespread vasodilation, leadingcauses widespread vasodilation, leading to hypotension and increased capillaryto hypotension and increased capillary permeability.permeability.
  20. 20. Neurogenic shockNeurogenic shock Neurogenic shock is the rarest form of shock.Neurogenic shock is the rarest form of shock. It is caused byIt is caused by traumatrauma to the spinal cordto the spinal cord resulting in the sudden loss of autonomic andresulting in the sudden loss of autonomic and motor reflexes below the injury level.motor reflexes below the injury level. Without stimulation by sympathetic nervousWithout stimulation by sympathetic nervous system the vessel walls relax uncontrollably,system the vessel walls relax uncontrollably, resulting in a sudden decrease in peripheralresulting in a sudden decrease in peripheral vascular resistance, leading to vasodilation andvascular resistance, leading to vasodilation and hypotension.hypotension.
  21. 21. Causes of Neurogenic Shock.Causes of Neurogenic Shock.  Some neurogenic factors that can cause loss of vasomotor tone includeSome neurogenic factors that can cause loss of vasomotor tone include the following:the following:  Deep general anesthesiaDeep general anesthesia often depresses the vasomotor center enough tooften depresses the vasomotor center enough to cause vasomotor paralysis, with resulting neurogenic shock.cause vasomotor paralysis, with resulting neurogenic shock.  Spinal anesthesia,Spinal anesthesia, especially when this extends all the way up the spinalespecially when this extends all the way up the spinal cord, blocks the sympathetic nervous outflow from the nervous systemcord, blocks the sympathetic nervous outflow from the nervous system and can be a potent cause of neurogenic shock.and can be a potent cause of neurogenic shock.  Brain damageBrain damage is often a cause of vasomotor paralysis. Many patients whois often a cause of vasomotor paralysis. Many patients who have had brain concussion or contusion of the basal regions of the brainhave had brain concussion or contusion of the basal regions of the brain develop profound neurogenic shock. Also, even though brain ischemiadevelop profound neurogenic shock. Also, even though brain ischemia for a few minutes almost always causes extreme vasomotor stimulation,for a few minutes almost always causes extreme vasomotor stimulation, prolonged ischemia (lasting longer than 5 to 10 minutes) can cause theprolonged ischemia (lasting longer than 5 to 10 minutes) can cause the opposite effect-total inactivation of the vasomotor neurons in the brainopposite effect-total inactivation of the vasomotor neurons in the brain stem, with consequent development of severe neurogenic shock.stem, with consequent development of severe neurogenic shock.
  22. 22. Obstructive shockObstructive shock  In this situation the flow of blood is obstructedIn this situation the flow of blood is obstructed which impedes circulation and can result inwhich impedes circulation and can result in circulatory arrest. Several conditions result incirculatory arrest. Several conditions result in this form of shock.this form of shock.
  23. 23. Cardiac tamponadeCardiac tamponade in which fluid in the pericardium prevents inflow ofin which fluid in the pericardium prevents inflow of blood into the heart (venous return). Constrictiveblood into the heart (venous return). Constrictive pericarditis, in which the pericardium shrinks andpericarditis, in which the pericardium shrinks and hardens, is similar in presentation.hardens, is similar in presentation.
  24. 24. ouTube - Cardiac tamponade English version.fl
  25. 25. ouTube - Atrial Fibrillation - What Is Atrial Fibrillation Video - Ab.f
  26. 26. Tension pneumothoraxTension pneumothorax  Through increased intrathoracicThrough increased intrathoracic pressure, bloodflow to the heart ispressure, bloodflow to the heart is prevented (venous return).prevented (venous return).
  27. 27. Massive pulmonary embolismMassive pulmonary embolism  is the result of a thromboembolic incident in theis the result of a thromboembolic incident in the bloodvessels of the lungs and hinders the returnbloodvessels of the lungs and hinders the return of blood to the heartof blood to the heart
  28. 28. ouTube - DVT _ Pulmonary Embolism.f
  29. 29. Aortic stenosisAortic stenosis Hinders circulation by obstructingHinders circulation by obstructing the ventricular outflow tractthe ventricular outflow tract
  30. 30.  Septic ShockSeptic Shock  Septic shockSeptic shock refers to a dangerously low bloodrefers to a dangerously low blood pressure (hypotension) that may result frompressure (hypotension) that may result from sepsis, or infection. This can occur through thesepsis, or infection. This can occur through the action of a bacterial lipopolysaccharide calledaction of a bacterial lipopolysaccharide called endotoxin.endotoxin.  The mortality associated with septic shock isThe mortality associated with septic shock is presently very high, estimated at 50% to 70%.presently very high, estimated at 50% to 70%.
  31. 31. Physiology of Treatment in ShockPhysiology of Treatment in Shock
  32. 32.  Replacement TherapyReplacement Therapy  Blood and Plasma Transfusion.Blood and Plasma Transfusion. If a person is in shockIf a person is in shock caused by hemorrhage, the best possible therapy is usuallycaused by hemorrhage, the best possible therapy is usually transfusion of whole blood.transfusion of whole blood.  If the shock is caused by plasma loss, the best therapy isIf the shock is caused by plasma loss, the best therapy is administration of plasma;administration of plasma;  when dehydration is the cause, administration of anwhen dehydration is the cause, administration of an appropriate electrolyte solution can correct the shock.appropriate electrolyte solution can correct the shock.  Whole blood is not always available, such as underWhole blood is not always available, such as under battlefield conditions. Plasma can usually substitutebattlefield conditions. Plasma can usually substitute adequately for whole blood because it increases the bloodadequately for whole blood because it increases the blood volume and restores normal hemodynamics.volume and restores normal hemodynamics.
  33. 33.  Plasma cannot restore a normal hematocrit, but the human bodyPlasma cannot restore a normal hematocrit, but the human body can usually stand a decrease in hematocrit to about half ofcan usually stand a decrease in hematocrit to about half of normal before serious consequences result, if cardiac output isnormal before serious consequences result, if cardiac output is adequate.adequate.  Sometimes plasma is unavailable. In these instances, variousSometimes plasma is unavailable. In these instances, various plasma substitutesplasma substitutes have been developed that perform almost exactlyhave been developed that perform almost exactly the same hemodynamic functions as plasma. One of these isthe same hemodynamic functions as plasma. One of these is dextran solution.dextran solution.  dextran,dextran, a large polysaccharide polymer of glucose . Certaina large polysaccharide polymer of glucose . Certain bacteria secrete dextran as a by-product of their growth, andbacteria secrete dextran as a by-product of their growth, and commercial dextran can be manufactured using a bacterialcommercial dextran can be manufactured using a bacterial culture procedureculture procedure  Dextrans of appropriate molecular size do not pass through theDextrans of appropriate molecular size do not pass through the capillary pores and, therefore, can replace plasma proteins ascapillary pores and, therefore, can replace plasma proteins as colloid osmotic agents.colloid osmotic agents.
  34. 34. Sympathomimetic DrugsSympathomimetic Drugs  AA sympathomimetic drugsympathomimetic drug is a drug that mimics sympathetic stimulation. Theseis a drug that mimics sympathetic stimulation. These drugs includedrugs include norepinephrinenorepinephrine,, epinephrineepinephrine , In two types of shock,, In two types of shock, sympathomimetic drugs have proved to be especially beneficial.sympathomimetic drugs have proved to be especially beneficial.  The first of these isThe first of these is neurogenic shock,neurogenic shock,  Administering a sympathomimetic drug takes the place of the diminishedAdministering a sympathomimetic drug takes the place of the diminished sympathetic actions and can often restore full circulatory function.sympathetic actions and can often restore full circulatory function.  The second type of shock in which sympathomimetic drugs are valuable isThe second type of shock in which sympathomimetic drugs are valuable is anaphylactic shock,anaphylactic shock, in which excess histamine plays a prominent role. Thein which excess histamine plays a prominent role. The sympathomimetic drugs have a vasoconstrictor effect that opposes thesympathomimetic drugs have a vasoconstrictor effect that opposes the vasodilating effect of histamine.vasodilating effect of histamine.  Sympathomimetic drugs have not proved to be very valuable in hemorrhagicSympathomimetic drugs have not proved to be very valuable in hemorrhagic shock. The reason is that in this type of shock, the sympathetic nervous systemshock. The reason is that in this type of shock, the sympathetic nervous system is almost always maximally activated by the circulatory reflexes already; sois almost always maximally activated by the circulatory reflexes already; so much norepinephrine and epinephrine are already circulating in the blood thatmuch norepinephrine and epinephrine are already circulating in the blood that sympathomimetic drugs have essentially no additional beneficial effect.sympathomimetic drugs have essentially no additional beneficial effect.
  35. 35. Treatment by the Head-Down Position.Treatment by the Head-Down Position.  When the pressure falls too low in most types of shock,When the pressure falls too low in most types of shock, especially in hemorrhagic and neurogenic shock, placingespecially in hemorrhagic and neurogenic shock, placing the patient with the head at least 12 inches lower thanthe patient with the head at least 12 inches lower than the feet helps tremendously in promoting venousthe feet helps tremendously in promoting venous return, thereby also increasing cardiac output. Thisreturn, thereby also increasing cardiac output. This head-down position is the first essential step in thehead-down position is the first essential step in the treatment of many types of shock.treatment of many types of shock.
  36. 36. Oxygen Therapy.Oxygen Therapy.  major effect of shock is too little delivery of oxygen tomajor effect of shock is too little delivery of oxygen to the tissues, giving the patient oxygen to breathe can bethe tissues, giving the patient oxygen to breathe can be of benefit in many instances. However, this frequentlyof benefit in many instances. However, this frequently is far less beneficial than one might expect, because theis far less beneficial than one might expect, because the problem in most types of shock is not inadequateproblem in most types of shock is not inadequate oxygenation of the blood by the lungs but inadequateoxygenation of the blood by the lungs but inadequate transport of the blood after it is oxygenated.transport of the blood after it is oxygenated.
  37. 37.  Treatment with Glucocorticoids (Adrenal CortexTreatment with Glucocorticoids (Adrenal Cortex Hormones That Control Glucose Metabolism).Hormones That Control Glucose Metabolism). Glucocorticoids are frequently given to patients inGlucocorticoids are frequently given to patients in severe shock for several reasons:severe shock for several reasons:  (1) increase the strength of the heart in the late stages(1) increase the strength of the heart in the late stages of shock;of shock;  (2) glucocorticoids stabilize lysosomes in tissue cells(2) glucocorticoids stabilize lysosomes in tissue cells and thereby prevent release of lysosomal enzymes intoand thereby prevent release of lysosomal enzymes into the cytoplasm of the cells, thus preventing deteriorationthe cytoplasm of the cells, thus preventing deterioration from this source; andfrom this source; and  (3) glucocorticoids might aid in the metabolism of(3) glucocorticoids might aid in the metabolism of glucose by the severely damaged cells.glucose by the severely damaged cells.
  38. 38. Circulatory ArrestCirculatory Arrest  A condition closely allied to circulatory shock is circulatoryA condition closely allied to circulatory shock is circulatory arrest, in which all blood flow stops.arrest, in which all blood flow stops.  This occurs frequently on the surgical operating table as a resultThis occurs frequently on the surgical operating table as a result ofof cardiac arrestcardiac arrest oror ventricular fibrillationventricular fibrillation. Ventricular fibrillation can. Ventricular fibrillation can usually be stopped by strong electroshock of the heart,usually be stopped by strong electroshock of the heart,  Cardiac arrest often results from too little oxygen in theCardiac arrest often results from too little oxygen in the anesthetic gaseous mixture or from a depressant effect of theanesthetic gaseous mixture or from a depressant effect of the anesthesia itself.anesthesia itself.  A normal cardiac rhythm can usually be restored by removingA normal cardiac rhythm can usually be restored by removing the anesthetic and immediately applying cardiopulmonarythe anesthetic and immediately applying cardiopulmonary resuscitation procedures, while at the same time supplying theresuscitation procedures, while at the same time supplying the patient's lungs with adequate quantities of ventilatory oxygen.patient's lungs with adequate quantities of ventilatory oxygen.

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