Hemorrhage and shock

Hemorrhagic shock occurs when the body begins to shut down due to large amounts of blood loss. People suffering injuries that involve heavy bleeding may go into hemorrhagic shock if the bleeding isn't stopped immediately. Common causes of hemorrhagic shock include: severe burns.

1. Hemorrhage and shock

2. HEMORRHAGE DEFINITION Disruption or “leak” in vascular system CAUSES OF BLOOD LOSS : 1. Internal Blunt force trauma e.g. Contusions, laceration, shear, fractures Penetrating trauma e.g. Punctures 2 . External General trauma e.g. Contusions, abrasions, lacerations, incisions, avulsions, amputation

3. Anatomical Type of Hemorrhage

4. Physiological Response to Hemorrhage Initial response: Stop bleeding by chemical means (hemostasis) Vascular reaction involves: Local vasoconstriction Formation of platelet plug Coagulation Growth of fibrous tissue into blood clot permanently closes and seals injured vessel If hemorrhage is severe, mechanisms may fail, resulting in shock (hypoperfusion)

5. MANAGEMENT: STOP the bleeding Supportive care measures Positioning of victim Ensuring A-B-C’s Maintenance of body temp Definitive management

6. MANAGEMENT: Apply direct pressure : with gloved hand, sterile dressing(s). Bleeding stopped? Yes No Elevate extremity : above victim’s heart, continue direct pressure Locate pressure point, apply pressure : maintain direct pressure over wound Treatment care for wound, seek definitive care Bleeding stopped? Bleeding stopped? No Bleeding from extremity? No Apply tourniquet (last resort) Yes No Definitive therapy

7. Direct pressure Apply pressure directly to wound site: Gloved hand, dressing If dressing soaks, add more gauze on top and press harder Apply direct pressure : with gloved hand, sterile dressing(s). Bleeding stopped ? Yes No Elevate extremity : above victim’s heart, continue direct pressure Locate pressure point, apply pressure : maintain direct pressure over wound Treatment : care for wound, seek definitive care Bleeding stopped ? Bleeding stopped ? No Bleeding from extremity? No Apply tourniquet (last resort ) Yes No Definitive therapy

8. Elevate wound site If possible, raise wound site above level of victim’s heart Apply direct pressure : with gloved hand, sterile dressing(s). Bleeding stopped? Yes No Elevate extremity : above victim’s heart, continue direct pressure Locate pressure point, apply pressure : maintain direct pressure over wound Treatment : care for wound, seek definitive care Bleeding stopped? Bleeding stopped? No Bleeding from extremity? No Apply tourniquet (last resort) Yes No Definitive therapy

9. Pressure points Find proximal “pressure point” and press on it (radial, ulnar , brachial, axillary , femoral arteries—not carotid) Apply direct pressure to site Apply direct pressure : with gloved hand, sterile dressing(s). Bleeding stopped? Yes No Elevate extremity : above victim’s heart, continue direct pressure Locate pressure point, apply pressure : maintain direct pressure over wound Treatment : care for wound, seek definitive care Bleeding stopped? Bleeding stopped? No Bleeding from extremity? No Apply tourniquet (last resort) Yes No Definitive therapy

10. Tourniquet Apply band above injury site, tighten to stop bleeding: Note time of application Reassess frequently Apply direct pressure : with gloved hand, sterile dressing(s). Bleeding stopped? Yes No Elevate extremity : above victim’s heart, continue direct pressure Locate pressure point, apply pressure : maintain direct pressure over wound Treat ment : care for wound, seek definitive care Bleeding stopped? Bleeding stopped? No Bleeding from extremity? No Apply tourniquet (last resort) Yes No Definitive therapy

11.   DEFINITION : shock , is a serious, life-threatening medical condition defined as an inadequate perfusion(hypoperfusion) of tissues which is insufficient to meet cellular metabolic needs. SIGNS OF SEVERITY: The severity of shock can be graded 1-4 based on the physical signs. This approximates to the effective loss of blood volume. SHOCK:

12. Conti… Grade 1 Up to about 15% loss of effective blood volume (~750ml in an average adult who is assumed to have a blood volume of 5 liters). This leads to a mild tachycardia and can be well tolerated in otherwise healthy individuals. Grade 2 Between 15-30% loss of blood volume (750-1500ml) will provoke a moderate tachycardia and begin to narrow the pulse pressure. capillary refill time will be extended.

13. Conti.. Grade 3 At 30 - 40% loss of effective blood volume (1500 - 2000 ml) the compensatory mechanisms begin to fail and hypotension, tachycardia and low urine output (<0.5ml/kg/hr in adults) are seen. Grade 4 At 40-50% loss of blood volume (2000 -2500 ml) profound hypotension will develop and if prolonged will cause end-organ damage and death.

14. PATHOPHYSIOLOGY OF SHOC K

15. Stages of shock. There are four stages of shock. 1. Initial   During this stage, Tissue hypoperfusional state causes hypoxia, mitochondria being unable to produce adenosine triphosphate (ATP). cell membranes become damaged anaerobic respiration.

16. Conti.. 2. Compensatory (Compensating)   Body employing physiological mechanisms, including neural, hormonal and bio-chemical mechanisms in an attempt to reverse the condition. The person will begin to hyperventilate in order to rid the body of carbon dioxide (CO 2 ). The baroreceptors in the arteries detect the resulting hypotension - release of adrenaline and noradrenaline .

17. Conti.. Increase in blood pressure. This is known as Cushing reflex and is the subjective identifying characteristic of this stage. Renin-angiotensin axis is activated and arginine vasopressin (Anti-diuretic hormone; ADH) is released vasoconstriction of the kidneys, gastrointestinal tract, and other organs to divert blood to the heart, lungs and brain. The lack of blood to the renal system causes the characteristic low urine production.

18. Conti.. 3. Progressive ( Decompensating ) When the cause of the crisis not be successfully treated, the shock will proceed to the progressive stage and the compensatory mechanisms begin to fail. Due to the decreased perfusion of the cells, sodium ions build up within while potassium ions leak out. As anaerobic metabolism continues, increasing the body's metabolic acidosis, the arteriolar smooth muscle and precapillary sphincters relax such that blood remains in the capillaries .Due to this, the hydrostatic pressure will increase and, combined with histamine release, this will lead to leakage of fluid and protein into the surrounding tissues.

19. Conti.. As this fluid is lost, the blood concentration and viscosity increase, causing sludging of the micro-circulation. The prolonged vasoconstriction will also cause the vital organs to be compromised due to reduced perfusion. If the bowel becomes sufficiently ischemic, bacteria may enter the blood stream, resulting in the increased complication of endotoxic shock . 4. Refractory (Irreversible)   At this stage, the vital organs have failed and the shock can no longer be reversed. Brain damage and cell death have occurred. Death will occur imminently.

20. TYPES:

21. HYPOVOLEMIC SHOCK Direct loss of effective circulating blood volume. This is the most common type of shock and based on insufficient circulating volume. Causes : Its primary cause is loss of fluid from the circulation (most often "hemorrhagic shock"). Causes may include internal bleeding, traumatic bleeding, or severe burns.

22. SIGNS OF HYPOVOLEMIC SHOCK

23. CARDIOGENIC SHOCK: This type of shock is caused by the failure of the heart to pump effectively. Causes: This can be due to damage to the heart muscle, most often from a large myocardial infarction. Other causes of cardiogenic shock include arrhythmias, cardiomyopathy, congestive heart failure (CHF), or cardiac valve problems. Signs: Similar to hypovolemic shock but in addition: Distended jugular veins due to increased jugular venous pressure Weak or absent pulse Arrhythmia, often tachycardia

24. DISTRIBUTIVE SHOCK As in hypovolaemic shock there is an insufficient intravascular volume of blood. This form of "relative" hypovolaemia is the result of dilation of blood vessels which diminishes systemic vascular resistance. Examples of this form of shock are:

25. Conti.. Septic shock Caused by systemic infection resulting in vasodilation leading to hypotension. can be caused by Gram negative bacteria which release an endotoxin which produces adverse biochemical, immunological and occasionally neurological effects which are harmful to the body, and other Gram-positive cocci , and certain fungi as well as Gram-positive bacterial toxins.

26. Signs of Septic Shock :

27. Conti.. Anaphylactic shock Caused by a severe anaphylactic reaction to an allergen, antigen, drug or foreign body causing the release of histamine which causes widespread vasodilation , leading to hypotension and increased capillary permeability. Anaphylactic shock

28. Conti.. Neurogenic (spinal) shock Neurogenic shock is the rarest form of shock. It is caused by trauma to the spinal cord resulting in the sudden loss of autonomic and motor reflexes below the injury level. Without stimulation by sympathetic nervous system the vessel walls relax uncontrollably, resulting in a sudden decrease in peripheral vascular resistance, leading to vasodilation and hypotension.

29. Conti.. Signs: As with hypovolemic shock but in high spinal injuries may also be accompanied by profound bradycardia due to loss of the cardiac accelerating nerve fibres from the sympathetic nervous system at T1-T4. The skin is warm and dry or a clear sweat line exists, above which the skin is diaphoretic. Priapism due to Peripheral nervous system stimulation

30. Conti.. OBSTRUCTIVE SHOCK: In this situation the flow of blood is obstructed which impedes circulation and can result in circulatory arrest. Several conditions result in this form of shock. Cardiac tamponade in which fluid in the pericardium prevents inflow of blood into the heart (venous return). Constrictive pericarditis , in which the pericardium shrinks and hardens. Tension pneumothorax Through increased intrathoracic pressure, bloodflow to the heart is prevented (venous return).

31. Conti.. Massive pulmonary embolism is the result of a thromboembolic incident in the blood vessels of the lungs and hinders the return of blood to the heart. Aortic stenosis hinders circulation by obstructing the ventricular outflow tract signs: Similar to hypovolemic shock but in addition: Distended jugular veins due to increased jugular venous pressure Pulsus paradoxus in case of tamponade

32. Conti.. OTHER PROPOSED TYPES OF SHOCK Revisions to the Hinshaw and Cox classification have been proposed. Several types of shock have been proposed as a " fifth type of shock", including hypoglycemic shock, cytotoxic shock and endocrine shock. However, each of these is actually a subtype of one of the four types of shock in Hinshaw and Cox's original model.

33. Conti.. For example: Endocrine shock Based on endocrine disturbances such as: Hypothyroidism (Can be considered a form of Cardiogenic shock) in critically ill patients, reduces cardiac output and can lead to hypotension and respiratory insufficiency. Thyrotoxicosis (Cardiogenic shock) may induce a reversible cardiomyopathy.

34. Conti.. Acute adrenal insufficiency (Distributive shock) is frequently the result of discontinuing corticosteroid treatment without tapering the dosage. However, surgery and intercurrent disease in patients on corticosteroid therapy without adjusting the dosage to accommodate for increased requirements may also result in this condition. Relative adrenal insufficiency (Distributive shock) in critically ill patients where present hormone levels are insufficient to meet the higher demands

35. MANAGEMENT OF SHOCK: Key Principles in Managing Shock: Open airway High-concentration oxygen Assist ventilation as needed Control external bleeding (if present) IV fluid replacement if appropriate Consider PASG Maintain body temperature Monitor ECG and oxygen saturation Reassess vital signs

36. Hypovolemic Shock Correct circulatory deficit and its causes Crystalloid fluid replacement for dehydration Volume replacement for hemorrhage. Critical care support Fluid volume replacement Large volume fluid replacement if: Systolic BP >100 mmHg AND Extremity injuries Blunt or penetrating trauma. IVFs to maintain systolic BP>90 mm Hg

37. Conti.. Cardiogenic Shock Improve pumping action of heart and manage dysrhythmias Fluid replacement Drug therapy (if needed) Cardiogenic shock due to myocardial ischemia or infarction requires: Reperfusion strategies Possible circulatory support Manage tension pneumothorax and cardiac tamponade

38. Conti.. Neurogenic Shock Treatment similar to hypovolemia Avoid circulatory overload Monitor lung sounds for pulmonary congestion Vasopressors may be indicated Anaphylactic Shock Subcutaneous epinephrine in acute anaphylactic reactions Other therapy Oral, IV, or IM antihistamines Bronchodilators Steroids reduce inflammatory response Crystalloid volume replacement Airway management

39. Conti.. Septic Shock Treatment Management of hypovolemia (if present) Correction of metabolic acid-base imbalance Prehospital care Respiratory support Vasopressors to improve cardiac output Thorough history to find source of sepsis Integration of Patient Assessment and the Treatment Plan

40. Conti.. For severe hemorrhage or shock: Rapid recognition Initiation of treatment Prevention of additional injury Rapid transport to appropriate hospital Advance notification to receiving facility Shock requires immediate interventions to preserve life. Therefore, the early recognition and treatment is essential even before a specific diagnosis is made. Most forms of shock seen in trauma or sepsis respond initially to aggressive intravenous fluids (e.g. 1 liter normal saline bolus over 10 minutes or 20ml/kg in a child). Therefore this treatment is usually instituted as the person is being further evaluated.

41. Conti.. Re-establishing perfusion to the organs is the primary goal through restoring and maintaining the blood circulating volume ensuring oxygenation and blood pressure are adequate, achieving and maintaining effective cardiac function, and preventing complications. Patients attending with the symptoms of shock will have, regardless of the type of shock, their airway managed and oxygen therapy initiated.

42. Conti.. In case of respiratory insufficiency (i.e. diminished levels of consciousness , hyperventilation due to acid-base disturbances or pneumonia ) tracheal intubation and mechanical ventilation may be necessary. A paramedic may intubate in emergencies outside the hospital, whereas a patient with respiratory insufficiency in-hospital will be intubated usually by a respiratory therapist , paramedic, or physician . The aim of these acts is to ensure survival during the transportation to the hospital; they do not cure the cause of the shock because Specific treatment depends on the cause.

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