Experienced clinicians can accurately assess LV ejection fraction with qualitative assessment. In critically ill patients however, cardiac output may be a more useful clinical end point in guiding resuscitation and hemodynamic support. For children and patients at extremes of size, cardiac index should be used instead of cardiac output. EPSS is a variable traditionally used with M-mode imaging where higher values have been associated with decreased LV EF; EPSS should not be used in isolation when assessing LV systolic function.

*approximations, actual values differ by sex and age

J Am Soc Echocardiogr. 2015;28:1-39

* EPSS >7mm associated with LVEF≤30% in ED population ordered an echo with sensitivity 100% and specificity 52% (Am J Emerg Med. 2014 Jun;32(6):493-7)

LV Systolic Function Calculators

SV = π (LVOT radius)² * LVOT VTI

CO=HR * SV

 CI=CO/BSA

BSA (Mosteller formula) =√[wt (kg) X ht (cm)/3600]

J Am Soc Echocardiogr. 2015;28:1-39

IVC/RAP

Although commonly used for assessment of fluid responsiveness the IVC has very limited utility for this indication except in extreme cases and is regarded as generally useless as a marker of fluid responsiveness by most. It can however be used to estimate RA pressures in spontaneously breathing non-mechanically ventilated patients, if a CVC is not available to get the true value.

*has not been validated in mechanically ventilated patients

J Am Soc Echocardiogr. 2015;28:1-39

Assessment of RVSP can be useful in patients with acute right heart failure, pulmonary hypertension and to monitor potentially harmful effects of mechanical ventilation (particularly in patients with severe lung injury). The simplified Bernoulli equation makes several assumptions including ignoring the blood’s viscous friction, flow acceleration and the initial blood velocity. RVSP is equal to PASP in the absence of obstruction or pressure gradient in the RVOT or PV.

J Am Soc Echocardiogr. 2010;23:685-713

RVSP Calculator

RVSP = 4V² + RAP

Assessment of diastolic dysfunction has limited applications at the point-of-care however there are associations with clinically relevant outcomes in critically ill patients. Diastolic dysfunction in conjunction with elevated LA pressures are important variables in patients with respiratory failure/pulmonary edema/ARDS, and those who fail to wean from mechanical ventilation. The 2016 guidelines simplified previous ones but unfortunately are cumbersome and frequently not possible to apply in critically ill patients. Greenstein and Mayo (2018) proposed a simplified approach to the assessment of diastolic dysfunction in critically ill patients using two variables listed below.

Diastolic Dysfunction: A Simplified Approach for Critically Ill Patients 

E/e’ <14 and/or e’<8cm/s suggest diastolic dysfunction and correlate with clinical outcomes in critically ill patients

CHEST. 2018; 153(3):723-732 (Greenstein & Mayo, 20018)

J Am Soc Echocardiogr. 2016;29:277-314

For a complete determination of diastolic dysfunction as per the American Society of Echocardiography Guidelines:

In patients without Normal LV EF or patients with normal EF but with myocardial disease:

J Am Soc Echocardiogr. 2016;29:277-314

For many hemodynamically significant or catastrophic valvular lesions good quality 2D and colour doppler evaluation are often sufficient to make the diagnosis. Acute left-sided valvular disease (particularly acute AR and acute MR) can lead to hemodynamic collapse and further deterioration despite standard therapies for shock (i.e. vasopressors) and patients with such potential valvulopathy should be evaluated urgently. The mainstay of POCUS assessment of valvular disease is with 2D echocardiography and colour doppler. Two-dimensional echocardiography should assess for valvular prolapse, flail, perforations, restriction/stenosis/calcification and associated structural changes (chamber dilation). Colour doppler is used to evaluate valvular function as turbulent flow and regurgitation cannot be visualized without it. The following tables include some of the basic quantitative measures of valvular disease which may be used to add confidence for clinical presentations based on 2D and colour doppler. An important caution is that they are based on clinically stable patients with chronic valvular disease largely for surgical assessment and many variables may not be present or could be altered in critically ill patients with acute presentations. Expert consultation should be sought for comprehensive valvular evaluation and quantitative assessment.

Supportive 2D findings: calcifications, restricted valve movement, bicuspid valves

Supportive colour doppler findings: turbulent flow through AoV

*for atrial fibrillation or other arrhythmias average values for several measures (5-10) should be reported

J Am Soc Echocardiogr. 2009;22(1):1-23

J Am Soc Echocardiogr. 2017;30:372-92

DI Calculator

AVA Calculator

LVOT Area Calculator

Supportive colour Doppler findings: large central jet, large flow convergence

J Am Soc Echocardiogr. 2017;30(4):303-371

Jet Width to LVOT Width Calculator

Supportive colour doppler findings: colour jet occupies large area of LA or travels to back wall of LA, large width between MV leaflets during systole

Acute MR: 2D findings are crucial as acute MR leads to rapidly developing hypotension and increased LA pressure which can cause typical echo findings of chronic MR to be underestimated (regurgitation jet by colour doppler and ventricular dilation).

***HR, SBP should be recorded at time of assessment as loading conditions have significant effect on gradients

J Am Soc Echocardiogr. 2017;30(4):303-371

Color Flow Jet Area: LA Area Calculator

Supportive colour doppler findings: large regurgitant jet, regurgitant flow may go all the way to hepatic vein.

J Am Soc Echocardiogr. 2017;30(4):303-371

Remember false positives from epicardial fat which typically has some echogenicity/speckles, moves with the visceral pericardium and is classically located adjacent to the RV wall

Note: size of effusion does not necessarily correlate with tamponade physiology (chronicity plays a large role), loculated effusions may be difficult to visualize with TTE especially in post cardiac surgery patients (TEE may be indicated)

J Am Soc Echocardiogr. 2013;26:965-1012

Always remember cardiac tamponade is a clinical diagnosis! Some findings may be attenuated, reversed or absent in patients on positive pressure ventilation. Typical signs of tamponade may not be present in patients with loculated/regional tamponade (most commonly post cardiac surgery patients). TEE may be necessary for accurate evaluation.

Supportive 2D findings: presence of pericardial effusion, dilated IVC, dilated hepatic veins, small LV cavity

Supportive doppler findings: reduced cardiac output along with the above 2D features

*some suggest threshold of 40% variability for TV inflow variability

**some suggest threshold of 25% for MR inflow variability

†positive pressure ventilation can reverse, attenuate and even abolish the effect of respiratory variation in cardiac tamponade

J Am Soc Echocardiogr. 2013;26:965-1012

TV Inflow Respiratory Variability Calculator

MV Inflow Respiratory Variability

Qualitative assessments of pleural effusion size are usually sufficient for most clinical decision making, however quantitative estimate of size may help in evaluation of evolution over time or in determining when the effusion has been completely drained. The following table does not apply to small or loculated pleural effusions.

A comprehensive transcranial doppler (TCD) assessment of multiple cerebral arteries can be technically challenging, time-consuming and outside the scope of even advanced POCUS practitioners. However isolated assessment of the middle cerebral artery through the transtemporal window is feasible, rapid and can provide valuable information at the point-of-care including midline shift, cerebral circulatory arrest, and vasospasm. It is imperative that the POCUS practitioner is aware of the applications and limitations of POCUS TCD.

CHEST 2019; 157(1): 142-150.

Surg Neurol 2004; 62:45–51.

Neurocrit Care 2012; 17:58–66.

Intensive Care Med 2003; 29:1088–1094.

Estimated ICP Calculator

Rarely acute presentation with hemodynamic significance, if acute suspected assess for obstructing MV vegetation

Supportive 2D findings: restricted opening, commissural calcification/fusion, LA enlargement, elevated RVSP

Supportive colour doppler findings: narrow diameter of turbulent flow at MV

***HR, SBP should be recorded at time of assessment as loading conditions have significant effect on gradients

J Am Soc Echocardiogr. 2009;22(1):1-23

MV Area by PHT Calculator

Supportive colour doppler findings: narrow diastolic inflow jet, turbulent flow during diastole

*all measures should be at end-inspiration, record HR during assessment

J Am Soc Echocardiogr. 2009;22(1):1-23

Pulmonic valve stenosis is usually congenital, and rare cause of acute illness.

J Am Soc Echocardiogr. 2009;22(1):1-23

Acute acquired pulmonic regurgitation with hemodynamic significance is rare yet mild PR is common in normal healthy subjects.

J Am Soc Echocardiogr. 2017;30(4):303-371

Pulmonary Annulus Ratio Calculator

A2C- apical 2-chamber

A4C- apical 4-chamber

A5C- apical 5-chamber

AoV- aortic valve

BSA- body surface area

CWD- continuous wave doppler

EPSS- end-point septal separation

IVC- inferior vena cava

LV- left ventricle

LVOT- left ventricular outflow tract

MV- mitral valve

PLAX- parasternal long axis

POCUS- point of care ultrasound

PSAX- parasternal short axis

PWD- pulsed-wave doppler

RAP- right atrial pressure

RV- right ventricle

RVSP- right ventricular systolic pressure

S4C- subcostal 4-chamber

SC- subcostal

SVC- superior vena cava

TAPSE- tricuspid annular plane systolic excursion

TDI- tissue doppler imaging

VCW- vena contracta

VTI- velocity time integral