1. Correct Answer: C. Administer a bolus of lactated Ringer’s

Rationale: This patient has undergone a redo joint replacement surgery that can be associated with significant blood loss and hypovolemia. His LV and RV contractility are hyperdynamic, obviating any need for inotropic support such as epinephrine. The almost complete collapse of the IVC with resting tidal ventilation suggests a preload deficit. This patient needs volume, but the hemoglobin of 9.5 in a patient without active ischemia or any documented history of cardiovascular disease is not an indication for blood transfusion. A bolus of a balanced crystalloid such as lactated Ringer’s makes the most sense in this scenario.

1. Boyd JH, Sirounis D, Maizel J, Slama M. Echocardiography as a guide to fluid management. Crit Care. 2016;20:274.

2. Correct Answer: A. Give fluid

Rationale: This patient has SAM of the mitral valve. While certain pathologies of the mitral valve predispose to SAM, anybody can develop it if hypovolemic enough and extremely hyperdynamic. Rather than closing appropriately in systole, the anterior leaflet of the mitral valve can get sucked into the LVOT and cause obstruction of the aortic outflow tract. The management consists of first giving fluid to allow the ventricle to expand in diastole. This way the anterior mitral leaflet will not be as close to the LVOT in the next systolic beat and less likely to get pulled into the LVOT. Other strategies are to administer beta-blockers and pure vasoconstrictors to make the ventricle less hyperdynamic and to create a higher afterload to prevent the anterior mitral leaflet from being sucked into the LVOT. Anything that decreases the LV afterload (such as an IABP) or increases the contractility of the ventricle (such as epinephrine and milrinone) can exacerbate SAM. The fact that this patient is developing SAM after a procedure with very little blood loss should prompt a search for another unrecognized source of bleeding.

1. Kapoor MC. Systolic anterior motion of the mitral valve in hypovolemia and hyperadenergic states. Indian J Anaesth. 2014;58(1):7-8.

3. Correct Answer: D. Aggressive volume resuscitation

Rationale: This patient has cardiac tamponade (focal to left atrium) after his open heart procedure. Unlike the generalized global effusion that is usually seen with “medical” pericardial tamponade, tamponade after cardiac surgery can often be a localized phenomenon and requires redo sternotomy. In the meantime, every effort needs to be made to maintain CO while preparing to open the chest. This means keeping the ventricles “full, fast and forward.” Aggressive volume resuscitation should commence to overcome the extrinsic pressure on the heart to allow it to fill, while a high HR will help maximize the limited CO. An epinephrine infusion would also help with contractility and increase HR. It is important to note that these are temporizing measures until the chest is reopened and the localized tamponade drained. Milrinone is not ideal in the setting of an acutely hypotensive patient, as it might worsen the hypotension. ECMO will not fix the underlying problem, while metoprolol may well result in cardiac arrest. TEE will be far more sensitive than TTE for the detection of a localized fluid collection after cardiac surgery.

1. Khanna S, Maheshwari K. Hemopericardium and acute cardiac tamponade-images in anesthesiology. Anesthesiology. 2018;128:1006.

4. Correct Answer: C. Use echo to determine her cardiac output (CO) and stroke volume (SV) then perform a passive leg raise (PLR) to look for an increase in SV

Rationale: Dynamic measures of volume responsiveness are far more accurate than static pressure-based readings, which have been demonstrated time and again to not correlate with volume responsiveness. Especially given the history of HFpEF, performing a PLR allows the autotransfusion of roughly 300 cc of blood into the right side of the heart. Measuring at least a 12% change in the SV or the LVOT VTI by echo is consistent with a patient who will respond to volume administration with an increase in the CO. Changes in IVC diameter as a measure of volume responsiveness have only been validated in the setting of independently breathing patients or patients who are paralyzed on mechanical ventilation with >8 cc/kg tidal volumes.

1. Miller A, Mandeville J. Predicting and measuring fluid responsiveness with echocardiography. Echo Res Pract. 2016;3(2):G1-G12.

5. Correct Answer: B. Normal end-diastolic diameter

Rationale: It cannot be emphasized enough that clinical decisions should rarely, if ever, be based on a single image. Still, Video 41.6 can lead you to obtain other images that may or may not support your initial suspicion. This patient is tachycardic, hypotensive, and hyperdynamic. The initial thought is that the patient must be hypovolemic. However, one needs to look closer. Pause the video and scroll through it slowly. A low systemic vascular resistance (SVR) state, such as sepsis, can often present the same way. However, in this short-axis view, if the patient is euvolemic but with a low SVR state, the end-diastolic diameter will generally be normal. A hypovolemic heart will not fill and thus will have a decreased end-diastolic diameter. Of course, the patient could be both hypovolemic and have a low SVR state and thus more specific measures of volume status should be obtained.

1. McLean AS. Echocardiography in shock management. Crit Care. 2016;20:275.

6. Correct Answer: D. Look at the mitral E/e’ as a measure of left atrial pressure

Rationale: This patient is showing signs of end-organ dysfunction that may benefit from additional volume administration and you have echocardiographic evidence that the patient should be volume responsive. However, just because a patient is volume responsive does not mean the patient absolutely needs to receive volume. The very valid concern here is that additional fluid may worsen this patient’s pulmonary edema, and we know that ARDS lungs tend to do better when they are dry. The concern is that additional volume will create cardiogenic pulmonary edema via a rise in the left atrial pressure. E/e′ is an accepted measure to reflect the left atrial pressure. This involves measuring mitral inflow velocity with PWD and tissue Doppler at the mitral annulus. An E/e′ > 14 indicates an elevated left atrial pressure and additional fluid has a significant chance of worsening this patient’s oxygenation. In a patient on low tidal-volume ventilation on significant PEEP, the IVC respiratory variation will be very insensitive for intravascular volume. Use of CWD on a PI jet can be used to determine the PADP, but this is a cheap surrogate for the actual left atrial pressure (LAP), which is what we really want to know.

1. Militaru C, Deliu R, Donoiu I, Alexandru DO, Military CC. Echocardiographic parameters in acute pulmonary edema. Curr Health Sci J. 2017;43(4):345-350.

7. Correct Answer: D. 500 cc fluid bolus

Rationale: While we want to avoid making clinical decisions based on only one image, Figure 41.1 shows respiratory variation in VTI in the LVOT in this paralyzed patient taking large tidal volumes and is highly suggestive that he will be volume responsive. Greater than 12% change in the peak velocities with respiration is highly sensitive and specific for volume responsiveness.

1. Feissel M, Michard F, Mangin I, Ruyer O, Faller JP, Teboul JL. Respiratory changes in aortic blood velocity as an indicator of fluid responsiveness in ventilated patients with septic shock. Chest. 2001;119(3):867-873.

8. Correct Answer: C. IJV distensibility >18%

Rationale: In a passively mechanically ventilated patient, IJV distensibility >18% prior to volume challenge has about 80% sensitivity and 85% specificity for identification of volume responsiveness.

1. Guarracino F, Ferro B, Forfori F, Bertini P, Magliacano L, Pinsky MR. Jugular vein distensibility predicts fluid responsiveness in septic patients. Crit Care. 2014;18:647.

9. Correct Answer: B. E/e′>14

Rationale: A plethoric IVC certainly helps suggest that the patient is not severely hypovolemic but does not really help us decide about volume overload. The same applies to SVC collapsibility, and it requires TEE to reliably obtain. Variation in the peak Doppler velocity in the LVOT may also help with the determination of volume responsiveness, but not necessarily if the patient may respond to diuresis. The E/e′ ratio is the ratio of the E-wave using PWD through the mitral valve to the tissue Doppler e′ wave on the mitral annulus. An E/e′ velocity ratio >14 is highly correlated with an elevation in left atrial pressure. A low E/e′ gives the intensivist more confidence that the pulmonary edema is noncardiogenic in origin.

1. Militaru C, Deliu R, Donoiu I, Alexandru DO, Military CC. Echocardiographic parameters in acute pulmonary edema. Curr Health Sci J. 2017;43(4):345-350.

10. Correct Answer: C. Perform a PLR and look for changes in SV

Rationale: A PLR causes the autotransfusion of approximately 300 cc of blood into the right side of the heart (Figure 41.13). A significant change in SV of >12% or so is consistent with the patient being volume responsive. Performing the PLR avoids giving a potentially detrimental fluid bolus and allows the intensivist to predict in advance if the patient should respond to fluid. VTI variation in the LVOT and IVC distensibility are really only applicable in the setting of tidal volumes over 8 cc/kg IBW. This patient with ARDS requires low tidal-volume ventilation so these measures would not be valid. The EDA by echo has limited sensitivity to assessment of volume responsiveness by itself.

1. Monnet X, Rienzo M, Osman D, et al. Passive leg raising predicts fluid responsiveness in the critically ill. Crit Care Med. 2006;34(5):1402-1407.

11. Correct Answer: D. Measure changes in VTI after an end-expiratory occlusion pressure

Rationale: While a PLR is a valuable tool to assess response to volume, this patient’s pelvic fractures would not make it a wise option to perform IVC distensibility. Changes in LVOT VTI have only been validated in the setting of large tidal volumes >8 cc/kg, which is not applicable to this patient with bilateral lung contusions. In this patient, an end-expiratory occlusion maneuver can be performed. An increase in CO >4% after an end-expiratory occlusion reliably predicts fluid responsiveness.

1. Jozwiak M, Depret F, Teboul JL, et al. Predicting fluid responsiveness in critically ill patients by using combined end-expiratory and end-inspiratory occlusions with echocardiography. Crit Care Med. 2017;45:e1131-e1138.

12. Correct Answer: D. Additional 2 L fluid bolus

Rationale: Low EDA < 10 cm² from a parasternal short-axis view is consistent with decreased preload, likely due to intra-abdominal hemorrhage in this patient. While fluid resuscitation should be initiated at that moment, a focused assessment with sonography in trauma (FAST) examination should also be performed to look for free fluid in the abdomen, suggestive of bleeding that might necessitate a return trip to the OR.

1. Miller A, Mandeville J. Predicting and measuring fluid responsiveness with echocardiography. Echo Res Pract. 2016;3:G1-G12.

13. Correct Answer: B. A change in PWD peak velocity through the LVOT of 14% from systolic beat to beat

Rationale: Changes in PWD flow through the LVOT >12% have been shown to predict fluid responsiveness and an increase in cardiac index >15%. It is important to keep in mind that this is only valid in patients mechanically ventilated at a tidal volume >8 cc/kg IBW and without spontaneous breathing efforts.

1. Feissel M, Michard F, Mangin I, Ruyer O, Faller JP, Teboul JL. Respiratory changes in aortic blood velocity as an indicator of fluid responsiveness in ventilated patients with septic shock. Chest. 2001;119:867-873.

14. Correct Answer: A. RV dilation without a change in BP

Rationale: RV dilation without increases in SV are an indicator of over-transfusion. Septal flattening indicated RV volume overload. Iatrogenic RV failure secondary to overaggressive rapid volume administration is an important consideration.

1. Feneley M, Gavaghan T. Paradoxical and pseudoparadoxical interventricular septal motion in patients with right ventricular volume overload. Circulation. 1986;74:230-238.

2. Miller A, Mandeville J. Predicting and measuring fluid responsiveness with echocardiography. Echo Res Pract. 2016;3:G1-G12.

15. Correct Answer: D. Peak LVOT peak velocity of 1.2 cm/s during expiration and 0.8 cm/s during inspiration

Rationale: Changes in LVOT peak velocities during inspiration and expiration >12% have been shown to be more sensitive and specific than changes in IVC diameter >8% in assessing for fluid responsiveness when tidal volumes of >8 cc/kg IBW are used transiently.

1. Vignon P, Repesse X, Begot E, et al. Comparison of echocardiographic indices used to predict fluid responsiveness in ventilated patients. Am J Respir Crit Care Med. 2017;195:1022-1032.

16. Correct Answer: C. Pulmonary artery VTI acceleration time

Rationale: Right ventricular outflow tract (RVOT) acceleration time (RVAT) is measured from the beginning of the flow to the peak flow velocity. It is important that the marker is placed at the peak first and then tracked back to the onset of flow, as the aim is to measure time taken to peak velocity and not the propagation. A value of >130 ms is normal, while <100 ms is highly suggestive of pulmonary hypertension. Mean pulmonary pressure is calculated by the formula: mPAP = 90 – (0.62*AT_RVOT). While not a direct measure of volume responsiveness, elevated mean pulmonary artery pressures may make the intensivist more wary of giving excessive fluids due to concern for RV volume overload.

1. Parasuraman S, Walker S, Loudon BL, et al. Assessment of pulmonary artery pressure by echocardiography—a comprehensive review. Int J Cardiol Heart Vasc. 2016;12:45-51.

17. Correct Answer: B. Phenylephrine

Rationale: In hypotensive patients with aortic stenosis (AS), phenylephrine is the drug of choice. LV afterload is relatively fixed due to the stenotic valve; increasing SVR will have minimal effect on myocardial work; also increasing the diastolic pressure will increase the coronary perfusion pressure and thus myocardial oxygen delivery. Phenylephrine will also decrease HR by its reflex bradycardia action, improve diastolic filling of the left ventricle, and thereby increase SV. Severe aortic stenosis is not a volume-depleted state unless there are other variables to also suggest hypovolemia.

1. Samarendra P, Mangione MP. Aortic stenosis and perioperative risk with noncardiac surgery. J Am Coll Cardiol. 2015;65(3):295-302.

18. Correct Answer: A. SVC collapsibility >36%

Rationale: SVC collapsibility >36% is very sensitive and specific for hypovolemia in patients on passive mechanical ventilation with >8 cc/kg IBW tidal volumes. TEE is required to image the SVC reliably. Mechanical ventilation will cause distension of the IVC, as it is not an intrathoracic structure. Collapsibility >50% is usually necessary in the spontaneously ventilating patient to suggest volume responsiveness.

1. Vieillard-Baron A, Chergui K, Rabiller A, et al. Superior vena caval collapsibility as a gauge of volume status in ventilated septic patients. Intensive Care Med. 2004;30(9):1734-1739.

19. Correct Answer: C. Tricuspid regurgitation

Rationale: Significant tricuspid regurgitation can cause a plethoric IVC, making respiratory variation in the size of the IVC to gauge volume status very unreliable. PWD interrogation of the hepatic veins shows reversal of the S wave, consistent with severe tricuspid regurgitation.

1. Zoghbi WA, Adams D, Bonow RO, et al. Recommendations for noninvasive evaluation of native valvular regurgitation: a report from the American Society of Echocardiography Developed in Collaboration with the Society for Cardiovascular Magnetic Resonance. J Am Soc Echocardiogr. 2017;30(4):303-371.

20. Correct Answer: A. Apical five chamber

Rationale: The apical five-chamber view allows the PWD beam to align in the direction of flow in the LVOT. Determination of the VTI, in combination with the calculated LVOT area, allows one to calculate the SV. Changes in SV can be used to guide fluid resuscitation.

1. Mercado P, Maizel J, Beyls C, et al. Transthoracic echocardiography: an accurate and precise method for estimating cardiac output in the critically ill patient. Crit Care. 2017;21:136.

21. Correct Answer: A. RV volume overload

Rationale/Critique: This parasternal short-axis TTE ( Video 41.9) shows flattening of the interventricular septum during diastole, consistent with high RV volume overload, and implies that additional fluid resuscitation is not going to be helpful. Flattening of septum during RV systole implies RV pressure overload.

1. Alaverdian A, Cohen RI. The right ventricle in critical illness. Open Crit Care Med J. 2010;3:38-42.

22. Correct Answer: C. Dynamic LVOT obstruction

Rationale: This patient likely has hypertrophic cardiomyopathy based on the hypertrophic left ventricle seen in Video 41.10. Acute decreases in LV afterload or hypovolemia may lead to SAM of the mitral valve, causing dynamic LVOT obstruction and hemodynamic collapse. Aggressive volume administration is the mainstay of treatment, along with beta-blockade and increasing SVR.

1. Oxlund CS, Poulsen MK, Jensen PB, Veien KT, Møller JE. A case report: hemodynamic instability due to true dynamic LVOT obstruction and systolic anterior motion following resuscitation: reversal of haemodynamics on supportive veno-arterial extracorporeal membrane oxygenation. Eur Heart J Case Rep. 2018;2(4):yty134.

23. Correct Answer: C. <5

Rationale: An IVC demonstrating >50% collapse with respiration with a diameter <2.1 cm is consistent with a very low CVP <5 mm Hg

1. Ilyas A, Ishtiaq W, Assad S, et al. Correlation of IVC diameter and collapsibility index with central venous pressure in the assessment of intravascular volume in critically ill patients. Cureus. 2017;9(2):e1025.Published online 2017 Feb 12.

24. Correct Answer: B. Increased stroke distance through the LVOT using PWD by 20%