SHOCK

HYPOVOLEMIC

100

Define Mild, Moderate and Severe Hypovolemic shock

What is Mild <20% blood volume; moderate 20-40% blood volume, severe >40% blood volume

200

What are the sources/causes of hypovolemic shock

What is hemorrhage, GI (diarrhea), Urinary, Insensible

300

What is the initial recommended solution and quantity used for volume resuscitation in hypovolemic shock?

What is isotonic saline (2-3L), pRBC/FFP/Platelets in massive hemorrhagic shock in 1:1:1

400

Why is end-organ damage frequently less in isolated hemorrhagic shock vs. septic/other forms of shock?

Due to absence of massive activation of inflammatory immune response & consequence organ injury and failure.

500

What are the physiologic characteristics of hypovolemic shock and their response.

What is CVP-> LOW, CO->LOW, SVR->HIGH, SVO2->LOW

SEPTIC

100

Define SIRS/sepsis/severe sepsis/septic shock

SIRS- At least 2/4 following conditions; T, RR, HR, WBC Sepsis-source present/obvious Severe sepsis-Sepsis with one or more signs of organ dysfxn shock-Hypotension (>1hr), Vasopressors, *persistent lactate elevation

200

What are the key factors that determine the severity of pts with sepsis and ultimate recovery?

1. microbe 2. site (pulm/abdomen); severe 3. Age 4. immune response of host/neutropenia 5. physiologic state of host 6. Genetic

300

What are the clinical manifestations and laboratory findings of pts suspected with septic shock?

1. SIRS w. source 2. AMS (delirium, agitation, confusion, disorientation) 3. Hypotension 4. DIC (isolated thrombocytopenia) 5. Lactate high/normal 6. Skin manifestations (petechiae, bullae, etc); warm skin 7. Oliguria/Transaminitis (high Bilis, high ALP) 8. High catabolic states (low Alb, high BUN, lipolysis) 9. High/low (DIC) fibrinogen, high ESR/CRP

400

What are the secondary superinfections associated in immunosuppressed pts with septic shock (due to loss of delayed-type hypersensitivity reactions)?

Opportunists: Stenotrophomonas Maltophilia, Acinetobacter Baumannii, Candida Albicans, HSV reactivation, Varicella-Zoster, CMV.

500

Empirical Antifungal Therapy should be strongly considered in which patient population of ICU?

1. Septic pts who have received at least 1 wk of broad spectrum Abx (still febrile, high/low WBC etc) 2. TPN 3. Neutropenic >5days; other severe immunosuppressed states (AIDS, Malignancy), prolonged Corticosteroid use.. 4. CVC >7 days, Hospitalized >7 days. 5. Previous documented fungal infections

CARDIOGENIC

100

What are the characteristics of Cardiogenic shock?

CS is characterized by systemic hypoperfusion due to severe depression of the cardiac index (CI <2.2 L/min/m2) and sustained systolic arterial hypotension (<90 mmHg)despite an elevated filling pressure (PCWP/CVP >18).

200

In pts with AMI, what are the factors (patient profile) that increase the risk of CS?

1. Older Age 2. Female 3. prior MI/reinfarction soon after first MI 4. DM 5. Anterior MI 6. 2/3 Triple vessel dz, 20% LMA 7. No stenosis as in LV apical ballooning (Takotsubo's CM)

300

Describe IABP (in detail) and its indications/contraindications.

In CS, mechanical assistance w/IABP augments both arterial diastolic pressure and CO. A sausage shaped balloon is introduced percutaneously into the Aorta via the femoral A. The balloon is automatically inflated during early diastole, augmenting coronary blood flow. the balloon collapses in early systole, reducing the afterload against which the LV ejects. Reduces myocardial O2 consumption, ameliorating ischemia. Stabilized pt temporarily until PCI or CABG. Contraindications: Aortic Regurgitation, suspected Aortic dissection

400

Describe the pathophysiology of CS (in detail).

CS is characterized by vicious cycle in which depression of the myocardial contractility (usu. ischemia) results in reduced CO and BP; which result in hypoperfusion of myocardium (coronaries) and further ischemia and depression of CO. Systolic myocardial dysfxn reduces SV and w/ diastolic dysfxn leads to elevated LVEDP and PCWP as well as pulm congestion/edema (hypoxia). If uninterrupted---> FATAL.

500

Describe the phenomenon of "Equalization of pressures"? It's Associated with which etiology of CS?

it's associated with Cardiac Temponade. High pressure chamber system causing equal elevation of pressures due to surrounding fluid in pericardial space. R. Atrial P=R. Ventricular diastolic P=Pulmonary A. diastolic P=PCWP=LVEDP

PATHOPHYSIOLOGY

100

How does compressive cardiogenic pathology cause shock?

With extrinsic compression, the heart and surrounding structures are less compliant and therefore inadequate diastolic filling impedes venous return and results in hypotension to shock.

200

What is the triad of pericardial temponade? Other signs of pericardial temponade (before imaging/Echo)?

Triad: hypotension, neck vein distension, muffled heart sounds. Signs: electrical alternans (ECG), pulsus paradoxus

300

How does Neurogenic pathology explain shock? What's the pathophysiology of Neurogenic shock?

Interruption of sympathetic vasomotor input after a high cervical spinal cord injury, cephalad migration of spinal anesthesia or devastating head injury. -Arteriolar dilation & venodilation causes pooling in the venous system--> decreases venous return and CO.

400

What's the hallmark of septic shock? Describe the 2 phases of Septic Shock (early, late). What are the physiologic characteristics 9 (CVP, Lactate, CO, SVR, SVO2) of each phase.

Hallmark: decrease SVR. Hyperdynamic (early)-HIGH CVP, HIGH CO, LOW Lactate, HIGH SVO2, HIGH CO, LOW SVR Hypodynamic (late)-LOW CVP, LOW CO, HIGH Lactate, LOW SVO2, LOW CO, HIGH SVR

500

What are the mechanisms involved explaining the elevation of lactate and decline of Albumin in pts with sepsis/shock.

HIGH Lactate-->Increased Glycolysis, anaerobic metabolism and impaired clearance of the resulting lactate and pyruvate by the liver and kidneys. LOW Albumin-->Increased protein catabolism, decreased hepatic synthesis & movement of Albumin intravascular to interstitial space.

MISC/OTHER

100

Provide 4 examples of compressive cardiogenic shock

What is pericardial temponade, tension PTX, positive pressure ventilation, herniation of abdominal viscera through diaphragm

200

What are the physiologic characteristics of Neurogenic shock (CVP, PCWP, CO, SVR, SVO2)?

ALL above are LOW in Neurogenic shock

300

What are the specific etiologies/disease processes that have higher rate of causing adrenal insufficiency in ICU?

1. N. Meningitidis bacteremia/sepsis 2. Disseminated TB 3. AIDS (CMV, MAI, Histo) 4. prior use of Glucocorticoids, megestrol, ETOMIDATE, ketoconazole

400

Define/explain Ecthyma Gangrenosum in the phase of septic shock? host?

Almost exclusively seen in Neutropenic pts. Cutaneous lesion caused by P. Aeruginosa. It's a bullous lesion, surrounded by edema, that undergoes central hemorrhage and necrosis. Poor prognostic sign.

500

What are the specific benefits of Mechanical Ventilation w. positive end-expiratory pressure on Pulmonary Edema.

1. Decreases both preload and afterload, improving cardiac function 2. redistributes lung/alveolar water from intraalveolar to extraalveolar space; better gas exchange 3. Increases lung/alveolar volume to avoid atelectasis.