ACCS Hemodynamic Monitoring and Shock Management 2 — Questions and Answers
Question 1: In hypovolemic shock, which hemodynamic pattern is expected?
- High CVP, high PAWP, high CO
- Low CVP, low PAWP, low CO with elevated SVR (Correct answer)
- Normal CVP, high CO, low SVR
- High SVR, high CO, low CVP
Correct answer: Low CVP, low PAWP, low CO with elevated SVR
Hypovolemic shock presents with decreased intravascular volume causing low filling pressures (CVP, PAWP) and low cardiac output, with compensatory increase in SVR.
Question 2: Passive leg raising (PLR) is used in the ICU primarily to assess which parameter?
- Pulmonary compliance
- Fluid responsiveness (Correct answer)
- Cardiac contractility
- Systemic vascular resistance
Correct answer: Fluid responsiveness
PLR is a reversible, dynamic maneuver that transiently increases venous return by autotransfusing blood from the lower extremities, allowing assessment of fluid responsiveness without giving actual fluid.
Question 3: Which dynamic parameter is MOST reliable for predicting fluid responsiveness in mechanically ventilated patients without arrhythmias?
- Central venous pressure (CVP)
- Pulmonary artery wedge pressure (PAWP)
- Pulse pressure variation (PPV) (Correct answer)
- Mean arterial pressure (MAP)
Correct answer: Pulse pressure variation (PPV)
PPV >13% in mechanically ventilated patients reliably predicts fluid responsiveness, as it measures cyclic changes in arterial pulse pressure caused by mechanical ventilation-induced changes in preload.
Question 4: Massive pulmonary embolism causing obstructive shock primarily impairs hemodynamics by:
- Decreasing systemic vascular resistance
- Blocking pulmonary blood flow and increasing right ventricular afterload (Correct answer)
- Directly depressing left ventricular contractility
- Causing severe mitral regurgitation
Correct answer: Blocking pulmonary blood flow and increasing right ventricular afterload
Massive PE obstructs pulmonary blood flow, acutely increasing RV afterload, causing RV failure and ultimately reducing left-sided cardiac output.
Question 5: Per the Surviving Sepsis Campaign guidelines, which vasopressor is recommended as the FIRST-LINE agent in septic shock?
- Epinephrine
- Vasopressin
- Norepinephrine (Correct answer)
- Dopamine
Correct answer: Norepinephrine
Norepinephrine is the first-line vasopressor for septic shock due to its potent alpha-1 adrenergic effects that increase SVR, with less tachycardia than dopamine or epinephrine.
Question 6: A central venous oxygen saturation (ScvO2) below 70% in a shock patient most likely indicates:
- Adequate oxygen delivery to tissues
- Increased oxygen extraction due to insufficient delivery (Correct answer)
- Systemic hyperoxia
- Decreased cellular oxygen consumption
Correct answer: Increased oxygen extraction due to insufficient delivery
ScvO2 <70% indicates tissues are extracting a greater-than-normal fraction of delivered oxygen because oxygen delivery is insufficient to meet metabolic demands.
Question 7: Which echocardiographic finding is MOST specific for cardiac tamponade?
- Left ventricular hypertrophy
- Diastolic collapse of the right ventricle (Correct answer)
- Severe mitral regurgitation
- Right ventricular hypertrophy
Correct answer: Diastolic collapse of the right ventricle
Diastolic RV collapse on echocardiography is a hallmark sign of cardiac tamponade, occurring when elevated pericardial pressure exceeds the low filling pressure of the thin-walled right ventricle.
ACCS Hemodynamic Monitoring and Shock Management 2
In hypovolemic shock, which hemodynamic pattern is expected?