Bedside Echo in Pulmonary Embolism

aka Cardiovascular Curveball 011

A 35 year-old female is brought to the emergency department after collapsing in a shopping centre.  Paramedics found her to be GCS 3 and shortly afterwards required CPR and 1mg adrenaline for profound bradycardia and no pulse.  Spontaneous output returned and no further drugs have been required to support her circulation.  She remains intubated and GCS 3.  There is little other history, except some information from a friend stating she had been on a trip to South America recently.

You perform a quick bedside echo while the paramedics are changing over their monitoring.

Questions

Q1. What are the obvious abnormalities on this echo?

  • Small LV cavity size with normal LV systolic function
  • Septal flattening consistent with RV pressure overload
  • Severely dilated RV with severely reduced systolic function

Q2. What is McConnell’s sign?

  • Echocardiographic pattern of RV dysfunction consisting of akinesia of the mid free wall but normal motion at the apex
  • 77% sensitivity and 94% specificity for diagnosis of pulmonary embolism

Q3. What are the echocardiographic features of right ventricular dysfunction in acute pulmonary embolism?

  • RV wall hypokinesis
    • Moderate or severe
    • McConnell’s sign
  • RV dilatation
    • End-diastolic diameter >30 mm in parastemal view
    • RV larger than LV in sobcostal or apical view
    • Increased tricuspid velocity >26 m/sec
    • Paradoxical RV septal systolic motion
  • Pulmonary artery hypertension
    • Pulmonary artery systolic pressure >30 mmHg
    • Dilated IVC with lack of respiratory collapse
Other echocardiographic features associated with increased mortality include patent foramen ovale and free-floating right-heart thrombus.

Q4. What are the indications for thrombolysis in acute pulmonary embolism?

Fibrinolysis in acute pulmonary embolism remains a controversial topic.

  • Most agree that cardiac arrest and haemodynamic instability (SBP < 90mmHg) are indications for thrombolysis.
  • Controversy surrounds thrombolysis for stable patients with RV dysfunction on echocardiography.
    • Treatment in this group has been shown to decrease pulmonary artery pressure and improve RV systolic function and pulmonary perfusion
    • This benefit must be weighed against the risk of haemorrhage with thrombolytic therapy.
    • Thrombolysis has not been shown to improve mortality.
  • Other treatment algorithms include the use of elevated Troponin and BNP to select which patients require urgent echocardiography

In haemodynamically stable patients with RV dysfunction, thrombolysis should be considered on a case-by-case basis

Q5. What would you do next?

  • Administer thrombolysis
    • Although stable at the moment, this patient has had a cardiac arrest from a pulmonary embolus and is potentially very unstable
    • She has severe RV dysfunction on echocardiography
    • There are no obvious contraindications to thrombolysis
    • Alteplase 50mg IV bolus

Q6. What was the response to treatment?

  • This echo was performed a few hours later. Already some improvement in RV dysfunction is evident.

This case illustrates the utility of bedside echocardiography in the emergency department.  Using the clinical history, a diagnosis of massive pulmonary embolism was made at the bedside and appropriate treatment could be administered almost immediately.

The pictures are from a real case, with some of the details changed.  Let’s just say that thrombolysis makes failed intubation interesting ……..

References

 

  • Fengler BT, Brady WJ (2009) Fibrinolytic Therapy in Pulmonary Embolism: an Evidence Based Algorithm. American Journal of Emergency Medicine. 27  84-89 [PMID 19041539]
  • Roy P et al (2005) Systematic Review and Meta-Analysis of Strategies for the Diagnosis of Suspected Pulmonary Embolism. BMJ 331:259 [PMID 16052017]
  • McConnell MV, Solomon SD, Rayan ME, Come PC, Goldhaber SZ, Lee RT (1996) Regional Right Ventricular Dysfunction Detected by Echocardiography in Acute Pulmonary Embolism.  American Journal of Cardiology. 78: 469-473 [PMID 8752195]
  • Goldhaber S (2002) Echocardiography in the Management of Pulmonary Embolism.  Annals of Internal Medicine. 136:691-700 [PMID 11992305]

 

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