Initial Shock Flashcards
Acute failure of the cardiovascular system to adequately deliver substrate or remove metabolic waste from tissues that results in anaerobic metabolism and acidosis
Shock
neurohumoral mechanisms maintain BP and tissue perfusion and during which shock can be reversed with appropriate therapy
Compensated stage of shock
when compensatory mechanisms fail and pathophysiologic derangements worsen
Progressive stage of shock
Without aggressive support, severe organ and tissue injury occurs leading to multiple organ failure and death
Refractory stage of shock
Hemorrhagic and non-hemorrhagic cause of fluid depletion
Hypovolemic shock
Common causes of hypovolemic shock?
Volume losses from vomiting and diarrhea secondary to GI infections
Hemorrhage (trauma, postsurgical, HI)
Plasma losses (burns, hypoproteinemia, pancreatitis)
Extra GI water losses (glucosuria diuresis, heat stroke)
When cardiac compensatory mechanism fail; may occur in children with preexisting myocardial disease or injury
Cardiogenic Shock
What are common causes of cardiogenic shock?
Viral myocarditis, anomalous left coronary artery arising from pulmonary artery (ALCAPA), incessant arrhythmias, drug ingestions (cocaine), metabolic derangements (hypoglycemia), and postop complications
What are the characteristics signs of cardiogenic shock?
Congestive heart failure (pulmonary rales, gallop cardiac rhythm), hepatomegaly, jugular venous distention, pitting peripheral edema, cardiomegaly on x-ray
What are the lab findings for cardiogenic shock?
Increased creatinine kinase, troponin, or brain natriuretic protein (BNP) levels
Due to obstruction of blood flow from certain types of congenital heart lesions or increased afterload of right or left ventricle
Obstructive shock
What are the common causes of obstructive shock?
Cardiac tamponade, pulmonary embolism, tension pneumothorax
There is an increase in acute WHAT in obstructive shock?
Acute increase in SVR due to sudden decrease in cardiac output and functional hypovolemia
Associated with peripheral vasodilation, pooling of venous blood, and decreased venous return to the heart
Distributive shock
What are the common causes of distributive shock?
Septic, neurogenic, anaphylactic shock, drug ingestions (such as atypical antipsychotics)
What shock is distributive shock usually associated with?
Hypovolemic shock
What is systemic inflammatory response syndrome?
Sepsis
Result of inadequate oxygen-releasing capacity
Dissociative shock
What are the common causes of dissociative shock?
Profound anemia, carbon monoxide poisoning, and methemoglobinemia
Special cause of distributive shock due to sudden disruption of sympathetic nerve stimulation to the vascular smooth vessel?
Neurogenic shock
What are the common causes of neurogenic shock?
Severe traumatic brain or cervical spine injury
How do you calculate cardiac output?
Stroke volume (volume ejected by L ventricle) x HR (ejection cycles/minute)
How do children normally present with shock?
Tachycardia and abnormal perfusion with normal BP
What are the clinical signs of successful resuscitation from shock?
Decrease in HR and RR; increase in BP; improve urine output to 0.5 mg/kg/hr; normalization of mental status, decreased capillary refill time, and warmth of distal extremities
What Central Venous Pressure (CVP) signals satisfactory initial fluid therapy?
> 8 to 12 mmHG
What does cutaneous near-infrared spectroscopy (NIRS) measure?
Venous-weighted oxyhemoglobin striation in underlying tissue bed and displays number that varies with local oxygen delivery and extraction
What counts as fluid refractory shock?
Persistence of insufficient tissue perfusion despite at least 60 mg/kg of fluid resuscitation and epinephrine/norepinephrine >1 ug/kg/min
What is the management of fluid refractory shock?
Treatment with:
Reverse etiologies
Vasoactive drug therapy
Reduce metabolic demand through mechanical ventilation [sedation and endotracheal intubation]
Stress-dose corticosteroid therapy [50-100 mg/m2/day]
ECMO support [successful for treating hemorrhagic shock]
What is early goal-directed therapy?
Prompt fluid resuscitation, targeted vasoactive therapy, early empiric antimicrobial therapy, and continuous monitoring of hemodynamic status
What vasoactive drugs do you use for “warm” shock?
Vasoconstrictor agents [Noradrenaline]
What vasoactive drugs do you use for “cold” shock?
Inotropic agents are most helpful [dobutamine, adrenaline, milrinone]
What are the signs of vasodilated shock?
Bounding pulses, warm extremities, normal capillary refill time
“Warm” shock
What are the signs of vasoconstricted shock?
Weak pulses, cool extremities, prolonged CRT
What is the most common cause of shock in the developed world?
Sepsis
What is the most common cause of shock worldwide?
Hypovolemic
What antibiotic choice for healthy patients with no central line?
Ceftriaxone
Vancomycin
What antibiotic choice for patients with immunocompromise, immunosuppressive meds, recent hospitalization, chronic medical condition with the central line?
Cefepime
Vancomycin
What antibiotic choice for oncology patients?
Cefepime
Vancomycin
Gentamicin
What antibiotic choice for intra-abdominal sources is suspected?
Piperacillin/tazobactam
Vancomycin
How do you decrease lactate levels?
Fluid resuscitation
Decrease energy need
What does ScvO2 measure?
The amount of oxygen in the blood returning to the heart
What should ScvO2 be?
Greater than 65-75%
What questions should you ask if ScvO2 is out of range?
Are you providing enough oxygen?
Is there enough hemoglobin?
Is cardiac output enough?
Where does the line terminate for Central Venous Line?
SVC in the right atrium
What does central venous pressure measure?
Volume status in the vessels (intravascular volume)
What is the CVP goal in shock in non-intubated/intubated patients?
8-12 cm H2O in non-intubated patients
12-15 cm H20 in intubated patients
What does near-infrared spectroscopy (NIRS) measure?
Pulse oximetry for brain or kidney
Measures end-organ perfusion (measures difference between oxygen delivery and oxygen leaving the organ)
What is the normal NIRS value?
65-75
What does a NIRS value of 100 mean?
The organ is not using an oxygen at all
If there is a decreasing NIRS, what do you do?
Fluid resuscitation
Vasoactive drugs
Increase oxygenation
What do you do with low CVP?
Provide fluid
What do you do with low BP?
Provide fluid and vasopressors
What do you do with low ScvO2?
Evaluate for energy expenditure and oxygen delivery
What do you do with low NIRS or high lactate?
Evaluate for energy expenditure
-Fever, tachycardia, sedation, paralysis
