قراءة
عرض

DR ARWA MAHMOOD FUZI ALSARRAF CONSULTANT INTERNIST /CARDIOLOGIST

Shock occurs when the rate of arterial blood flow is in adequate to meet tissue metabolic needs, this results is regional hypoxia, and lactic acidosis, then eventual end organ damage and death.


Hypotension, tachycardia, oliguria, altered mental status, cool clammy skin. Peripheral hypoperfusion

Hypovolemic : decreased intravascular volume (blood loss, dehydration, burn) Cardiogenic: inability of heart to maintain tissue perfusion due to decreased cardiac output with adequate intravascular volume(acute MI, CMP, acute valvuler lesions, arrhythmias, myocardial contusion)

Obstructive : acute decrease in cardiac output (tamponade, pneumothorax, pulmonary embolism) Distributive :reduction in systemic vascular resistance causing inadequate cardiac output in spite of normal intravascular volume (septic shock, anaphylactic shock, neurogenic shock)


Hypotension, weak or thready peripheral pulses, cold or mottled extremities. Splanchnic vasoconstriction may lead to oliguria, bowel ischemia, and hepatic dysfunction. Mentation may be normal or altered (restlessness, agitation, confusion, lethargy, or coma).

Low JVP Narrow pulse pressure from reduced stroke volume

Elevated JVP Global hypoperfusion with oliguria, altered mental status, cool extremities. Pulmonary edema if there is left sided heart failure

Central venous pressure (CVP) may be elevated. Signs of causative disease.

Hyperdynamic heart sounds. Worm extremities Wide pulse pressure (Due to large stroke volume) Causes for distributive shock Septic shock : evidence of infection and organ hypoperfusion ( lactic acidosis, oliguria, altered mental status) despite adequate volume resuscitation

2. Anaphylactic shock Evidence of allergen exposure ( injected, ingested, contact, inhaled). 3. Neurogenic shock Evidence of CNS injury and hypotension despite volume resuscitation. 4. Acute adrenal insufficiency Hypocortisolism

Complete blood count Serum electrolytes Glucose Cardiac enzymes and b nitrouretric peptides (BNP) Lactate Coagulation parameters Type and cross match Arterial blood gas determination Blood cultures

CXR Echo transthoracic TTE and transesophageal echoTEE

ECG Arterial line placement (for bp and arterial oxygen monitoring ) Foley catheter for uop monitoring Pulmonary artery catheter can distinguish cardiogenic from septic and monitor effect of volume resuscitation or pressure medication CVP line and measurement can suggest volume status

Cardiac index is often low in cardiogenic shock and high in septic shock SVR is often low in septic and neurogenic shock and high in cardiogenic and hypovolemic shock.


Prompt diagnosis Basic life support with assessment of circulation , airway and breathing. Airway intubation and mechanical ventilation (ventilatory failure should be anticipated in patient with shock and severe metabolic acidosis). Intravenous access and fluid resuscitation with cardiac monitoring

Cardiac monitoring to detect myocardial ischemia or malignant arrhythmias, and treated with standard ACLS (advanced cardiac life support) protocols . Check glucose level and treat hypoglycemia immediately with 50% dextrose IV Place arterial line. Place folly catheter to monitor UOP


Placement of central venous catheter(CVC) for infusion of fluid and medication. for hemodynamic pressure measurement CVP CVP less than 5 mmhg suggest hypovolemia, more than18 mmhg suggest fluid overload, cardiac failure, tamponade or pulmonary hypertension. for central venous oxygen saturation


measurement of pulmonary artery pressure. left sided filling pressure or pulmonary capillary wedge pressure (PCWP) measure cardiac opt and mixed venous o2 s

to maintain * CVP 8-12 mmhg * mean arterial bp 65 mmhg or more * cardiac index of 2-4 L/min/m2 * ScvO2 greater than 70%


Hemorrhagic shock : rapid infusion of blood component Hypovolemic shock: rapid boluses of isotonic crystalloid (0.9 % saline or ringer lactate) in 1 L increments Cardiogenic shock : smaller fluid challenges in the absence of fluid overload with 250 ml increments Septic shock : requires large volume of fluid for resuscitation, usually more than 2 L

only administered after adequate fluid resuscitation if hypotension with high cardiac output use vasopressor, if low cardiac opt with high filling pressures use inotrops Norepinephrine (alpha and beta agonist) initial dose 1-2 mcg/min IV infusion, maintenance 2-4 mcg/min, up to 10-30 mcg/min mainly used for vasodilatory shock, but can be used in all causes


Epinephrine (alpha and beta agonist ) used in severe shock and acute resuscitaion, it is vasopressor of choice in anaphylactic shock Dose initially 1 mcg/min iv infusion, then titrate to 1-10 mcg/min. Dopamine action according to dose - low dose (2-5 mcg/kg/min) dopamenergic effect increasing GFR and urine out put - medium dose 5-10 mcg/kg/min, has beta1 adrenergic effect, increasing HR &contractility, and increase uop - high dose more than 10 mcg/kg/min has alpha effect lead to peripheral vasoconstriction max 50mcg/kg/min

Phenylephrine first line hyperdynamic septic shock Dobutamine (predominantly beta agonist) increase contractility and decrease afterload used for patient with low cardiac output and high PCWP, but without hypotension initial dose is 0.1-0.5mcg/kg/min IV infusion usual dose is 2-20 mcg/kg/min


Amrinone or milrinone (phosphodiesterase inhibitors) can be substituted for dobutamine. Vasopressin (ADH) for distributive or vasodilatory shock, also in sepsis if 2 drugs needed

2. Corticosteroids For shock secondary to adrenal insufficiency 3. Antibiotics empiric broad spectrum antibiotics for septic shock after obtaining appropriate cultures. 4. Correction of acidosis by sodium bicarbonate


Transcutaneous or transvenous pacing Placement of intra- arterial balloon bumps. Revascularization by percutaneous angioplasty (PCI),or coronary artery bypass surgery (CABG)

Pericardiocentesis . chest tube. Catheter – directed thrombolytic therapy for obstructive shock Urgent hemodialysis or hemofiltration for acute kidney injury




رفعت المحاضرة من قبل: Omar Almoula
المشاهدات: لقد قام 14 عضواً و 290 زائراً بقراءة هذه المحاضرة








تسجيل دخول

أو
عبر الحساب الاعتيادي
الرجاء كتابة البريد الالكتروني بشكل صحيح
الرجاء كتابة كلمة المرور
لست عضواً في موقع محاضراتي؟
اضغط هنا للتسجيل