REVIEW QUESTIONS
1. Which statement accurately refl ects the utility of the physical assessment of the cardiovascular status of a child?
A. Capillary refi ll time is independent of ambient temperature.
B. Pulse pressure will be decreased in conditions characterized by low systemic vascular resistance.
C. Tachycardia, in and of itself, is a sensitive and specifi c sign of hemodynamic instability.
D. The peripheral skin to ambient temperature gradient (dTp-a) decreases during states of high systemic vascular resistance.
E. Urine output is infl uenced by many factors and therefore should not serve as a proxy for distal tissue perfusion.
2. In the following illustration of an arterial waveform, which number identifi es the incisura or dicrotic notch?
A 2
3
1
4 5
Hyperlactatemia may also occur due to drug or toxin effects. Any drug that interferes with the TCA cycle or oxidative phosphorylation may lead to excessive lactate production.
These medications includes metformin, salicylates, HMG CoA reductase inhibitors, cya- nide, iron and propofol. Inborn errors of metabolism may also present with profound eleva- tions in the serum lactate. Examples of inborn errors of metabolism that may present with lactic acidosis include pyruvate dehydrogenase defi ciency, pyruvate decarboxylase defi - ciency, glucose-6-phosphatase defi ciency, fructose-1,6-diphosphatase defi ciency and mito- chondrial disorders. In addition, certain malignancies may be associated with hyperlactemia.
Finally, hyperlactatemia may be caused by elevation in the D -isomer of lactate. This is usu- ally observed in states of intestinal bacterial overgrowth as occurs in short gut syndrome.
A. 1 B. 2 C. 3 D. 4 E. 5
3. Which statement best describes wave frequency and resonance?
A. A system with high resonance may falsely increase the dia- stolic pressure by as much as 30%.
B. An accurate monitoring system at heart rates of 180 beats per minute (bpm) should have its natural frequency be equal to 6 Hz.
C. If the frequency of the system is in the same range as the fre- quency of the arterial waveform, the amplitudes of the waves become additive and can overestimate the systolic pressure.
D. Resonant augmentation of the arterial pressure wave causes an artifactual increase in both systolic and diastolic recorded pressures.
E. The effect of resonance becomes less problematic when the monitoring system has a low natural frequency and the heart rate is high.
4. Which statement is correct regarding arterial monitoring sys- tems?
A. Damping describes the interaction between the oscillatory energy of a wave and the electrical properties of the monitor- ing system.
B. Due to the turbulent fl ow and the high oxygen tension found in arteries, infections associated with arterial catheters are extremely uncommon.
C. Pressure monitoring devices must be leveled to the point at which the catheter enters the artery.
D. The delivery of a small “fast fl ush” to the arterial catheter allows for quantifi cation of excessive resonance within the system.
E. The phlebostatic axis is the determined by locating the junc- tion of the vertical line drawn down from the clavicle and the horizontal mid-axillary line.
5. Which of the following describes the alternating beats of larger and smaller pulse pressures observed in the setting of a normal rhythm with severe left ventricular systolic dysfunction?
A. Pulsus alternans B. Pulsus bisferiens C. Pulsus paradoxicus D. Pulsus parvus et tardus E. Systolic pressure variation
6. Which of the following describes the exaggerated fall in the systolic blood pressure observed during inspiration?
A. Pulsus alternans B. Pulsus bisferiens C. Pulsus paradoxicus D. Pulsus parvus et tardus E. Systolic pressure variation
7. Which of the following describes the decreased and delayed upstroke in the arterial waveform characteristic of severe left ventricular outfl ow obstruction?
A. Pulsus alternans B. Pulsus bisferiens C. Pulsus paradoxicus D. Pulsus parvus et tardus E. Systolic pressure variation
8. Which of the following describes the rise in systolic blood pressure observed early in a positive pressure breath?
A. Pulsus alternans B. Pulsus bisferiens C. Pulsus paradoxicus D. Pulsus parvus et tardus E. Systolic pressure variation
9. Which of the following describes the brisk arterial upstroke followed by two peaks observed in hyperdynamic states?
A. Pulsus alternans B. Pulsus bisferiens C. Pulsus paradoxicus D. Pulsus parvus et tardus E. Systolic pressure variation
10. A 6 month old male infant, 2 weeks following the repair of Tetralogy of Fallot (patch closure of the ventricular septal defect and relief of the right ventricular outfl ow obstruction with sparing of the pulmonary valve) develops pneumonia, respiratory failure and septic shock. He is endotracheally in- tubated and administered two normal saline fl uid boluses (to- tal = 40 mL/kg). His positive end expiratory pressure (PEEP) is set at 7 cm H 2 O and his peak inspiratory pressures range from 27 to 30 cm H 2 O. An internal jugular central venous catheter with the tip positioned at the superior vena cava/right atrial junction and a radial arterial catheter are placed. His arterial catheter demonstrates a 20 mm Hg systolic gradient during a positive pressure breath. The following hemodynamic data are available:
Heart rate 179 bpm
Blood pressure 67/45 mm Hg Central venous pressure 14 mm Hg Central venous oxygen saturation 53%
Arterial oxygen saturation 89% on 80% FiO 2 Arterial lactate 6 mmol/L
Which of the following statements is MOST correct?
A. The central venous pressure is refl ective of adequate volume replacement.
B. The decreased arterial saturation is likely due to left to right shunting across a residual ventricular septal defect.
C. The hypotension is best corrected by the addition of an infu- sion of epinephrine.
D. The positive end expiratory needs to be reduced to increase right ventricular preload.
E. There is a need for additional intravenous volume replacement.
11. In assessing a normal central venous pressure (CVP) wave- form (Figure), the a wave represents which of the following?
CVP
a c v
x y
A. The decline in atrial pressure that occurs during atrial relax- ation and ventricular systole.
B. The displacement of the tricuspid valve toward the atrium during isovolumic ventricular contraction.
C. The fall in atrial pressure that occurs as the tricuspid valve opens and the atrium is drained.
D. The increase in intra-atrial pressure observed during atrial contraction that occurs at the end of ventricular diastole.
E. The rise in atrial pressure during the end of ventricular sys- tole as the atrium fi lls with venous blood from the inferior and superior venous cava.
12. In assessing a normal central venous pressure (CVP) waveform (Figure), the c wave represents which of the following?
CVP a c
x
v y
A. The decline in atrial pressure that occurs during atrial relax- ation and ventricular systole.
B. The displacement of the tricuspid valve toward the atrium during isovolumic ventricular contraction.
C. The fall in atrial pressure that occurs as the tricuspid valve opens and the atrium is drained.
D. The increase in intra-atrial pressure observed during atrial contraction that occurs at the end of ventricular diastole.
E. The rise in atrial pressure during the end of ventricular sys- tole as the atrium fi lls with venous blood from the inferior and superior venous cava.
13. In assessing a normal central venous pressure (CVP) waveform (Figure), the x descent represents which of the following?
CVP
a c v
x y
A. The decline in atrial pressure that occurs during atrial relax- ation and ventricular systole.
B. The displacement of the tricuspid valve toward the atrium during isovolumic ventricular contraction.
C. The fall in atrial pressure that occurs as the tricuspid valve opens and the atrium is drained.
D. The increase in intra-atrial pressure observed during atrial contraction that occurs at the end of ventricular diastole.
E. The rise in atrial pressure during the end of ventricular sys- tole as the atrium fi lls with venous blood from the inferior and superior venous cava.
14. In assessing a normal central venous pressure (CVP) waveform (Figure), the v wave represents which of the following?
CVP
a c v
x y
A. The decline in atrial pressure that occurs during atrial relax- ation and ventricular systole.
B. The displacement of the tricuspid valve toward the atrium during isovolumic ventricular contraction.
C. The fall in atrial pressure that occurs as the tricuspid valve opens and the atrium is drained.
D. The increase in intra-atrial pressure observed during atrial contraction that occurs at the end of ventricular diastole.
E. The rise in atrial pressure during the end of ventricular sys- tole as the atrium fi lls with venous blood from the inferior and superior venous cava.
15. In assessing a normal central venous pressure (CVP) waveform (Figure), the y descent represents which of the following?
CVP a c
x
v y
A. The decline in atrial pressure that occurs during atrial relax- ation and ventricular systole.
B. The displacement of the tricuspid valve toward the atrium during isovolumic ventricular contraction.
C. The fall in atrial pressure that occurs as the tricuspid valve opens and the atrium is drained.
D. The increase in intra-atrial pressure observed during atrial contraction that occurs at the end of ventricular diastole.
E. The rise in atrial pressure during the end of ventricular sys- tole as the atrium fi lls with venous blood from the inferior and superior venous cava.
16. The right ventricular (RV) waveform and the pulmonary ar- tery (PA) waveform can be distinguished from each other by which of the following?
A. It is diffi cult to distinguish the waveforms without fl uoro- scopic visualization of the catheter tip.
B. The PA diastolic pressure is usually greater than the RV dia- stolic pressure.
C. The PA systolic pressure is usually greater than the RV sys- tolic pressure.
D. The RV diastolic pressure is usually greater than the PA dia- stolic pressure.
E. The RV systolic pressure is usually greater than the PA sys- tolic pressure.
17. Which disease state is most consistent with the following hemodynamic profi le in a critically ill 10 year old child?
Heart rate: 129 bpm Blood pressure: 81/68 mm Hg
Pulmonary artery occlusion pressure (PAOP): 24 mm Hg Pulmonary vascular resistance index (PVRI): 128 dyne-s/cm 5 /m 2 Cardiac index (CI): 2.0 L/min/m 2
Central venous/right atrial pressure: 6 mm Hg Stroke volume index (SVI): 20 mL/beat/m 2 Lactate: 10 mmol/L
SmvO 2 : 50%
SaO 2 : 91%
A. Cardiomyopathy with biventricular dysfunction
B. Congestive heart failure secondary to a large atrial septal defect with left to right shunting
C. Gastroenteritis with hypovolemia
D. Myocarditis with left ventricular dysfunction
E. Pulmonary hypertension with right ventricular dysfunction 18. Which of the following Fick derived equations is correct?
A.
B.
C.
D.
E.
19. Which statement regarding the use of thermodilution to determine cardiac output is MOST correct?
A. A fundamental assumption during thermodilution is that the fl uid injected into the right atrium will have complete and anatomi- cally appropriate mixing prior to reaching the pulmonary artery.
B. A high cardiac output state results in a large area under the thermodilution curve.
C. Right heart cardiac output should equal left heart output even in the presence of an intracardiac shunt.
D. The area under the thermodilution curve is determined by the change in fl ow over time.
E. The area under the thermodilution curve is in the numerator of the Stewart-Hamilton formula used to calculate cardiac output.
20. Which of the following is correct regarding central venous saturation (ScvO 2 ) and mixed venous saturation (SmvO 2 ) ? A. Decreased oxygen delivery raises both ScvO 2 and SmvO 2 B. Decreased oxygen consumption lowers both ScvO 2 and
SmvO 2
C. In normal conditions, SmvO 2 is slightly higher than the ScvO 2 D. ScvO 2 is best measured in the lower right atrium to reliably
predict SmvO 2
E. SmvO 2 is best measured in the right ventricle just below the tricuspid valve.
21. A 6 year old boy with chronic granulomatous disease presents with septic shock. Prior to arrival in the pediatric intensive care unit, he is intubated, treated with antibiotics, receives fl uid resuscitation with 80 mL/kg of crystalloid and is started on an infusion of dopamine at 15 mcg/kg/min. He has central
arterial and venous catheters placed that allow for intermit- tent transpulmonary thermodilution and continuous pulse contour analysis for determination of the cardiac output.
The following hemodynamic data are obtained:
Heart rate: 170 bpm
Blood pressure: 70/54 mm Hg Cardiac index (CI): 1.5 L/min/m 2 Central venous pressure: 6 mm Hg Stroke volume index (SVI): 21 mL/beats/m 2
Stroke volume variation (SVV) > 20% (normal <10%) Systemic vascular resistance index (SVRI): 1,600 dyne-s/cm 5 /m 2 Lactate: 12 mmol/L
ScvO 2 : 45% (Right atrium) SaO 2 : 91%
Hemoglobin: 7.5 mg/dL
Positive End Expiratory Pressure (PEEP): 8 cm H 2 O Fraction of inspired oxygen (FiO 2 ): 0.65
The most appropriate next step in the management of this boy would be to:
A. begin an infusion of epinephrine at 0.05 mcg/kg/min.
B. begin an infusion of milrinone at 0.5 mcg/kg/min.
C. begin an infusion of norepinephrine at 0.05 mcg/kg/min.
D. continue volume resuscitation with a packed red cell transfusion.
E. increase his PEEP to 10 cm H 2 O.
22. A 9 month old infant with dilated cardiomyopathy presents in shock with severe left ventricular dysfunction. He requires intubation and the initiation of a milrinone infusion. He requires the addition of a nitroprusside infusion for afterload reduction.
The infusion is titrated to 4 mcg/kg/min to maintain systolic blood pressure between 70-85 mm Hg. On the 6th PICU day he develops a new metabolic acidosis with a base defi cit (−7). A serum lactate level is elevated (7.3 mmol/L) and the superior vena cava oxygen saturation is 88%. Which of the following explanations for an elevated lactate level is most worrisome in this clinical scenario?
A. Decreased lactate clearance secondary to impaired renal clearance.
B. Elevated lactate production secondary to catecholamine- induced “hyperglycolysis”.
C. Impaired lactate metabolism secondary to an inborn error of metabolism.
D. Increased lactate production from tissue hypoperfusion.
E. Increased lactate production secondary to cellular inability to extract delivered oxygen.
23. A 12 year old girl with acute lymphoblastic leukemia is neutro- penic and develops septic shock. Prior to arrival in the pediat- ric intensive care unit, she is treated with antibiotics and is fl uid resuscitated with 80 mL/kg of isotonic intravenous crystalloid fl uids. She has both central arterial and venous catheters placed that allow intermittent transpulmonary thermodilution and con- tinuous pulse contour analysis for cardiac output determination.
She appears toxic, fl ushed and has a hyperbrisk capillary refi ll.
The following hemodynamic data are obtained:
Heart rate: 150 bpm
Blood pressure: 100/34 mm Hg Cardiac index (CI): 6.5 L/min/m 2 Central venous pressure: 16 mm Hg Stroke volume index (SVI): 51 mL/beats/m 2
Storke volume variation (SVV) < 10% (normal <10%) Systemic vascular resistance index (SVRI): 400 dynes-s/cm 5 /m 2
2
Ao 2 pa 2
CO DO
C O C O
= −
Ao 2 pul
pv 2 pa 2
Q C O
C O C O
= −
pul pv 2 pul pa 2 2
Q (C O )=⎡⎣Q (C O )⎤⎦+DO
syst pv 2 syst Ao 2 2
Q (C O )=⎡⎣Q (C O )⎤⎦−VO
2 syst
Ao 2 pa 2
Q VO
C O C O
= −
Lactate: 9 mmol/L ScvO 2 : 88% (Right atrium) SaO 2 : 100%
Hemoglobin: 9.5 mg/dL
The most appropriate next step would be to:
A. begin an infusion of epinephrine at 0.05 mcg/kg/min.
B. begin an infusion of milrinone at 0.5 mcg/kg/min.
C. begin an infusion of norepinephrine at 0.05 mcg/kg/min.
D. continue volume resuscitation with a packed red cell transfusion.
E. diurese with furosemide (1 mg/kg).
24. A 12 year old girl with acute lymphoblastic leukemia is neutro- penic and develops septic shock. Prior to arrival in the pediat- ric intensive care unit, she is treated with antibiotics and is fl uid resuscitated with 80 mL/kg of isotonic intravenous crystalloid fl uids. She has both central arterial and venous catheters placed that allow intermittent transpulmonary thermodilution and con- tinuous pulse contour analysis for cardiac output determination.
She appears toxic, fl ushed and has a hyperbrisk capillary refi ll.
The following hemodynamic data are obtained:
Heart rate: 150 bpm
Blood pressure: 100/34 mm Hg Cardiac index (CI): 6.5 L/min/m 2 Central venous pressure: 16 mm Hg Stroke volume index (SVI): 51 mL/beats/m 2
Stroke volume variation (SVV) < 10% (normal <10%) Systemic vascular resistance index (SVRI): 400 dynes-s/cm 5 /m 2 Lactate: 9 mmol/L
ScvO 2 : 88% (Right atrium) SaO 2 : 100%
Hemoglobin: 9.5 mg/dL
The elevated S CV O 2 (88%) is likely indicative of which of the following?
A. Catheter tip positioning near the orifi ce of the coronary sinus B. Drug toxicity
C. Inadequate oxygen uptake at the cellular level D. Insuffi cient cardiac output to provide tissue perfusion E. Successful resuscitation
25. In the following illustration of an arterial waveform, which number identifi es peak left ventricular ejection?
A 2
3
4 5
1
A. 1 B. 2 C. 3 D. 4 E. 5
26. In the following illustration of an arterial waveform, which number identifi es the anacrotic limb?
A 2
3
4 5
1
A. 1 B. 2 C. 3 D. 4 E. 5
27. In the following illustration of an arterial waveform, which number identifi es diastolic runoff?
A. 1 B. 2 C. 3 D. 4 E. 5
1 3 2 A
4 5