Monday 30 September 2019

Comparison of manual pulse palpation, cardiac ultrasonography and Doppler ultrasonography to check the pulse in cardiopulmonary arrest patients

This study aimed to determine which method of pulse check is the best during CPR. Should we do the traditional manual pulse check, use our ultrasound to look at the heart (POCUS) or use a Doppler on the femoral artery.

Of course, to do such a study would require comparison against a gold standard and calculation of test performance by reporting sensitivity and specificity.

This study did none of this.

In addition, the manuscript is incredibly poorly presented and should not have been published in its current form (example below). Given the sloppiness of the paper, one should really question the veracity of the research conducted.

A more detailed USG was performed when the rhythm returned to normal or when the patient accepted exitus.

As this study looks to be fatally flawed, I should probably stop here… but I will mention a few things.

This study allegedly enrolled 137 patients in a single very busy Turkish ED. Two ED residents with a year of POCUS experience did all of the echo’s. All three methods to check the pulse were performed at the same time; at the start of resuscitation, at 15 minutes and at the end of efforts or ROSC. They tried to maintain blinding by curtain set up as seen in the picture.

They claim the echo’s only took 4 seconds to perform. Contrasted with doppler taking 8 seconds and manual palpation 10 seconds. This sounds impressive (and contrary to other published reports) until you consider the two ED residents were not blinded to the study aims. Nor did they mention how the times were measured.

The study claims the echo was the best (as it was always right by design) and there were a bunch of false positive and negatives with the Doppler and manual palpation.

I’m a big proponent of POCUS and have already incorporated echo as my default pulse check. I can get the images quickly and I feel a I get a better sense of cardiac contractility than with other methods. I occasionally find important pathology such as tamponade, RV strain, dissection, catastrophic valvular regurgitation or cardiac standstill.

AHA/ACC, ILCOR and ERC guidelines support POCUS in arrest, but caution it should not interfere with high quality CPR. To be fair, there has been little high-quality research. There is no doubt we should encourage further formal study with robust methods and design. 

We don’t want our patients to accept exitus.


Zengin S, Gumusboga H, Sabak M, et al. Comparison of manual pulse palpation, cardiac ultrasonography, and Doppler ultrasonography to check the pulse in cardiopulmonary arrest patients. Resusitation 2018;133:59-64. [link toarticle]

Pregnancy-Adapted YEARS Algorithm for Diagnosis of Suspected Pulmonary Embolism

There must be something in the coffee houses that make the Dutch so sensible.

Just like the HEART score, they have created another simple clinical decision instrument that has face validity (regardless if it is actually proven). This time, it’s for investigating potential PE in pregnancy.

This multicentre, international trial was conducted at 18 hospitals over 5 years. They included pregnant adults who had been referred to the ED or obstetrical ward with suspected PE.

They aimed to determine whether their pregnancy-adapted YEARS algorithm could be used to avoid diagnostic imaging in this at-risk population.

Simply put, the algorithm is as follows:

  • Three criteria were assessed in all patients; clinical signs of DVT, haemoptysis, whether PE was thought to be the most likely diagnosis. D-dimer was measured.
  • Patients with clinical signs of DVT underwent ultrasound.
  • If a patient did not meet any of the three YEARS criteria and the D-dimer was less than 1000ng/ml a diagnosis of PE was considered to be ruled out.
  • If a patient had any of the YEARS criteria and the D-Dimer was less than 500ng/ml then PE was ruled out.
  • All the remaining patients were referred for CTPA.

The primary outcome was the occurrence of symptomatic DVT or PE within 3 months. (Patients did not undergo routine screening.) Secondary outcome was the proportion of patients where CTPA was not indicated.


About 500 women were included. 20 (4%) of patients had a PE diagnosed at baseline. Only one patient (0.2%) was diagnosed with a DVT in the follow up period. There were no PE’s and no deaths. CTPA was avoided (not indicated) in about 40% of patients. The efficiency of the algorithm was better during the first trimester (65% avoided CTPA).

Major limitations?

Gold standard screening tests were not performed to look for subsequent DVT or PE. Much like it is hard to find a fever if you don’t take a temperature, it is hard to find VTE if you are not testing for it. But they reportedly did look if patients had symptoms… which is the practical and ethical approach in this RCT.

It is hard for this study to claim safety regarding mortality as death from PE in pregnancy is reasonably low. It will never be feasible to enrol enough patients in an RCT to asses mortality benefit.

What’s the take home?

Using clinical gestalt (i.e. the 3 YEARS criteria) and a pregnancy adjusted D-dimer is a sensible approach. 


Van der Pol LM, Tromeur C, Bistervels IM, et al. Pregnancy-Adapted YEARS Algorithm for Diagnosis of Suspected Pulmonary Embolism. N Engl J Med 2019;380:1139-49. [link to article]

Sunday 29 September 2019

IV cefazolin plus probenecid vs oral cephalexin for the treatment of skin and soft tissue infections

It is traditionally thought that IV antibiotics are superior to those given orally. But IV administration comes with extra time, cost, resources, and possibly not necessary.

To answer the question, these authors designed an elegant bias-busting study. It was a prospective, multicentre, double-dummy blind, randomised non-inferiority trial conducted in two Canadian ED’s.

However, the authors soon learned valuable lessons in performing an RCT; feasibility and generalisability.

They had quite strict inclusion and exclusion criteria that hindered patient recruitment. In addition, this also made any conclusions rather difficult to generalise to a broader patient population.

They included adult patients who had what they thought was mild to moderate cellulitis (a bit subjective). They excluded very mild patients, those with renal disease, prior MRSA, prior antibiotic use in the preceding 7 days, infections requiring I&D or debridement, two or more signs of SIRS, bites, PVD, perioperative wounds, etc, etc.

They even excluded patients with BMI greater than 30. That’s most of Canada!

Arguably defeating the whole purpose of the study, participants were brought back to the ED every day for 7 days of treatment. This is hardly decreasing resources and simulating real conditions.

The primary outcome was failure rate at 72 hours. About 300 patients were thought needed to power the study to a 10% non-inferior margin.

Why 72 hours? A great pearl… 

“This end point is beyond the clinical extension of redness that may be seen in the first 24-48 hours of therapy which would not typically represent treatment failure.”


Over 4 years, they screened 2855 patients for eligibility but finally gave up after randomising 206 patients.

The proportion of patients failing therapy at 72 hours was not statistically different and about 5% in both groups. The authors conclude cephalexin is just as good as IV cefazolin for mild to moderate cellulitis.

It is probably true that we overdo IV antibiotics for many infectious disease processes. But it is disappointing to see such a well-designed study design ultimately unable to provide us with much useful information.


Dalen D, Fry A, Campbell, S, et al. IV cefazolin plus probenecid vs oral cephalexin for the treatment of skin and soft tissue infections. Emerg Med J 2018;35:492-429 [link to article]

Friday 27 September 2019

Duration of ECG monitoring of ED patients with Syncope

How long do we need to monitor patients after an episode of syncope? What a great question…

These authors used data that came from a large multicentre study that developed the Canadian Syncope Risk Score (CSRS). They enrolled consecutive adult patients who presented within 24 hours of a simple syncopal episode.

They collected data on baseline characteristics and were eventually able to risk stratify patients by using their newly derived syncope score into low, intermediate and high-risk groups.

The primary outcome was serious arrhythmic conditions (arrhythmias, interventions for arrhythmias, and unexplained death) over 30 days.

The 30 day follow up was a tremendous undertaking. They had structured review of all available medical records, subsequent visits, hospitalisations, and deaths. They performed a scripted telephone follow up at 30 days and they looked at administrative records for subsequent visits.

A whopping 5581 patients were analysed. As expected, only a small number 7.5% had serious outcomes. The syncope score seemed to work pretty well. The low risk group had 0.4% 30-day arrhythmic outcomes. The intermediate and high risk were 8% and 25% respectively.

The authors state that one-half of arrhythmic events were identified within 2 hours of ED arrival in low risk patients and within 6 hours in the intermediate and high-risk patients.

Based on this, the authors suggest either 2 or 6 hours of cardiac monitoring is enough after syncope but outpatient cardiac monitoring for 15 days in higher risk patients.

There were a few problems…

Only 11% of the patients were hospitalised and the median ED length of stay was only 4 hours. It is no surprise that they found half of the events early on when they were actually looking. It is quite possible that many events were missed when the patients were not being monitored at home. However, they should have at least they should have picked up on mortality.

Remember the extraordinary work they did in assessing the 30-day outcomes? Unfortunately, quality of data is often inversely proportional to the effort and complexity in obtaining it. In other words, they may have been making conclusions based on bad data.  It’s hard to know.

There have been several attempts at creating a clinical decision instrument for syncope. Unfortunately, these instruments don’t tend to work in complex disease processes. The CSRS has not  been externally validated nor compared to clinician gestalt.

What’s the take home point?

From an evidence-based medicine standpoint, I don’t believe this single study is enough to justifiably change practice. But in our hearts, we all know that low risk patients probably don’t need to be watched very long… and high-risk patients need to be monitored longer. 2 or 6 hours? Who knows…


Thiruganasambandamooooorhylinglangadong, V, Rowe B, Sivilotti M, et al. Duration of Electrocardiographic Monitoring in Emergency Department Patients with Syncope. Circulation 2019;139:1396-1406. [link to article]