Acute Pulmonary Embolism: Size does matter and ECG can give us clues

Acute pulmonary embolism (PE) is a common condition that can be both severe and difficult to diagnose. Half of all acute PE cases are diagnosed in the emergency department, and acute PE follows acute coronary syndrome as the second most common cause of sudden unexpected death in outpatients. Also, right ventricular dysfunction is a consequence of massive/submassive acute pulmonary embolism and correlates with a poor prognosis and high mortality rate. Although an ECG lacks both sensitivity and specificity for acute PE, there are some clues that can help in determining the size of an acute PE.

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By Salim Rezaie, MD|2019-09-10T13:35:37-07:00Oct 8, 2013|Cardiovascular, ECG, Pulmonary|

Rivaroxaban for Pulmonary Embolism: One pill and done?

With Dr. Jeff Tabas giving a lecture on the perennially hot topic of pulmonary embolism (PE) at the upcoming UCSF High Risk EM Conference (main link, PDF Brochure) in San Francisco May 22-24, 2013, I thought I would get a sneak peek into his discussion points.

Rivaroxaban for Pulmonary Embolism: One pill and done?
By Prathap Sooriyakumaran, MD and Jeffrey Tabas, MD
UCSF-SFGH Emergency Medicine (more…)

By Michelle Lin, MD|2026-06-16T16:01:48-07:00Apr 3, 2013|Cardiovascular, Pulmonary, Tox & Medications|

Patwari Academy videos: Respiratory failure and ventilators

Dr. Rahul Patwari reviews the basics of respiratory physiology, the pathophysiology behind respiratory failure, and ventilator management. What do all the ventilator settings mean?

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By Michelle Lin, MD|2019-01-28T22:00:36-08:00Mar 17, 2013|Patwari Videos, Pulmonary|

Lytics for sub-massive PE: Ready for primetime?

There was recently a great study published in the American Journal of Cardiology (2012) by Sharifi et al¹, questioning whether we should be considering tPA in patients other than those patients with massive pulmonary embolism (PE)? You know the big “Saddle Embolus” we all fear? Well it turns out this is only about 5% of all PEs.

Should we be considering tPA in patients with sub-massive PEs?

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By Salim Rezaie, MD|2019-09-10T13:37:21-07:00Mar 13, 2013|Cardiovascular, Pulmonary, Tox & Medications|

PE in pregnancy: which diagnostic tests do you use?

Pulmonary embolism (PE) can be a deadly disease and one of the most challenging diagnosis to make in a pregnant patient. Patients may present with signs and symptoms that might also be present in a normal uncomplicated pregnancy. Even in nonpregnant patients, the diagnosis of venous thromboembolism (VTE) such as PE can be quite challenging.

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By Javier Benitez, MD|2026-06-16T16:01:58-07:00Mar 6, 2013|Cardiovascular, Ob/Gyn, Pulmonary|

PV card: VBG versus ABG

You obtain a venous blood gas (VBG) on a patient with a COPD exacerbation because you are concerned about hypercarbia. You get a value of 55 mmHg. How correlative is that compared to an arterial blood gas (ABG). There has been a lot of literature on how well the pH correlates between the ABG and VBG but what about pCO2?

A small study (n=89) from 2012¹ found that with a cutoff of pCO2 < 45 mmHg, the venous pCO2 is 100% sensitive in ruling out arterial hypercarbia. When the pCO2 was ≥ 45 mmHg, the VBG was less correlative.

Below is a review by Dr. Michelle Reina (EM resident at Univ of Utah) and Dr. Rob Bryant (Intermountain Medical Center in Utah) of the VBG vs ABG correlative data, along with a proposed algorithm on what to do with patients with COPD exacerbation.

What is your practice with an elevated pCO2 value on VBG?

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Adapted from [1–5]
Go to ALiEM (PV) Cards for more resources.

Updated 1/31/13 at 2 pm PST:

Changed range of pH correlation between VBG and ABG = 0.03-0.04
Was typo in abstract of Kelly et al article.² Stated difference between pHs was 0.4, rather than 0.04 as described in main results text.

References

McCanny P, Bennett K, Staunton P, McMahon G. Venous vs arterial blood gases in the assessment of patients presenting with an exacerbation of chronic obstructive pulmonary disease. Am J Emerg Med. 2012;30(6):896-900. [PubMed]
Kelly A, McAlpine R, Kyle E. Venous pH can safely replace arterial pH in the initial evaluation of patients in the emergency department. Emerg Med J. 2001;18(5):340-342. [PubMed]
Ma O, Rush M, Godfrey M, Gaddis G. Arterial blood gas results rarely influence emergency physician management of patients with suspected diabetic ketoacidosis. Acad Emerg Med. 2003;10(8):836-841. [PubMed]
Middleton P, Kelly A, Brown J, Robertson M. Agreement between arterial and central venous values for pH, bicarbonate, base excess, and lactate. Emerg Med J. 2006;23(8):622-624. [PubMed]
Koul P, Khan U, Wani A, et al. Comparison and agreement between venous and arterial gas analysis in cardiopulmonary patients in Kashmir valley of the Indian subcontinent. Ann Thorac Med. 2011;6(1):33-37. [PubMed]