ResUS in the Literature: Echo Integrated ACLS

Journal:  Chinese Journal of Traumatology

Title: Echocardiography integrated ACLS protocol versus conventional cardiopulmonary resuscitation in patients with pulseless electrical activity cardiac arrest.

Authors: Chardoli M, Heidari F, Rabiee H, Sharif-Alhoseini M, Shokoohi H, Rahimi-Movaghar V.

Date: 2012

Design: Prospective interventional study, patients presenting with PEA arrest were randomized into two groups.

• Group A, trained emergency physicians performed echocardiography.
• Group B underwent ACLS protocol without echocardiography

Measures: Evaluated cardiac activity, right ventricle dilation, left ventricle function, pericardial effusion/tamponade and IVC size. The presence or absence of mechanical ventricular activity (MVA) and evidence of PEA reversible causes were recorded. The return of spontaneous circulation (ROSC) and death were evaluated in both groups.

Results:

100 patients enrolled (50 in Group A, 50 in Group B)

The resuscitation outcomes for PEA arrest patients with/without cardiac activity on ResUS are described in Table 1

Importantly: The presence of  ventricular activity had 43% positive predictive value for ROSC. The absence of ventricular activity had 100% positive predictive value for death

The authors noted:
"ROSC was recorded in 17 (34%) and 14 (28%) patients in Groups A and B, respectively. However, resuscitation results did not indicate any significant difference between the two groups (P=0.52, power=0.06)"

Commentary: 

The only randomized trial of ResUS cited by AHA 2015 guidelines in support of ResUS during CPR.  ResUS "may be considered during the management of cardiac arrest, although its usefulness has not been well established (Class IIb, LOE C-EO)".

• This study demonstrates no survival benefit in patients receiving ResUS. 
• A qualified sonographer needs to be present 
• ResUS should not interfere with the standard treatment.
• No cardiac activity = death

Small number of cases, single center, More (large scale) studies are needed!

Posted by: A Adedipe, MD

ResUS Pearl: Confirmation of ETT Placement

POCUS can be used as an adjunct method for verification of proper endotracheal tube (ETT) placement, and can be used in real-time during or immediately following laryngoscopy.

Advantages

Helpful for emergency intubations where ETCO₂ has a higher error rate:

• Cardiac Arrest 
• Status Asthmaticus
• Pulmonary Edema
• Pulmonary Embolism 

Additionally, unlike ETCO₂ detectors, ultrasound can help confirm appropriate ETT depth.

Technique
Place a high frequency linear probe in the transverse position just cephalad to the suprasternal notch.

US Findings

Several different confirmatory findings have been described to determine ETT location, primarily relying on the exclusion of esophageal intubation. To date, there is no sonographic finding that is widely accepted amongst investigators.

References

American College of Emergency Physicians Board of Directors. Verification of Endotracheal Tube Placement. policy statement. Revised April 2009.

Favot, M. Ultrasound for Verification of Endotracheal Tube Location. Academic Life in Emergency Medicine.  March 2015.

Submitted by: A Hughes, MD

ResUS in the Literature: AHA Guidelines 2015

Ultrasound During Cardiac Arrest^{ALS 658}

Bedside cardiac and noncardiac ultrasound are frequently used as diagnostic and prognostic tools for critically ill patients.⁴⁴ Ultrasound may be applied to patients receiving CPR to help assess myocardial contractility and to help identify potentially treatable causes of cardiac arrest such as hypovolemia, pneumothorax, pulmonary thromboembolism, or pericardial tamponade.⁴⁵ However, it is unclear whether important clinical outcomes are affected by the routine use of ultrasound among patients experiencing cardiac arrest.

 

2015 Evidence Summary

One limited study with a small sample size was identified that specifically addressed the utility of ultrasound during cardiac arrest. This study evaluated bedside cardiac ultrasound use during ACLS among adult patients in pulseless electrical activity arrest and found no difference in the incidence of ROSC when ultrasound was used.⁴⁶

 

2015 Recommendations—Updated

Ultrasound (cardiac or noncardiac) may be considered during the management of cardiac arrest, although its usefulness has not been well established (Class IIb, LOE C-EO). If a qualified sonographer is present and use of ultrasound does not interfere with the standard cardiac arrest treatment protocol, then ultrasound may be considered as an adjunct to standard patient evaluation (Class IIb, LOE C-EO).

Clinical Assessment of Tracheal Tube Placement^{ALS 469}

 

Attempts at endotracheal intubation during CPR have been associated with unrecognized tube misplacement or displacement as well as prolonged interruptions in chest compression. Inadequate training, lack of experience, patient physiology (eg, low pulmonary blood flow, gastric contents in the trachea, airway obstruction), and patient movement may contribute to tube misplacement. After correct tube placement, tube displacement or obstruction may develop. In addition to auscultation of the lungs and stomach, several methods (eg, waveform capnography, CO2 detection devices, esophageal detector device, tracheal ultrasound, fiberoptic bronchoscopy) have been proposed to confirm successful tracheal intubation in adults during cardiac arrest.

 

2015 Evidence Summary

An ultrasound transducer can be placed transversely on the anterior neck above the suprasternal notch to identify endotracheal or esophageal intubation. In addition, ultrasound of the thoracic cavity can identify pleural movement as lung sliding. Unlike capnography, confirmation of ETT placement via ultrasonography is not dependent on adequate pulmonary blood flow and CO₂ in exhaled gas.^76–78 One small prospective study of experienced clinicians compared tracheal ultrasound to waveform capnography and auscultation during CPR and reported a positive predictive value for ultrasound of 98.8% and negative predictive value of 100%.⁷⁸ The usefulness of tracheal and pleural ultrasonography, like fiberoptic bronchoscopy, may be limited by abnormal anatomy, availability of equipment, and operator experience.

 

2015 Recommendations—Updated

Continuous waveform capnography is recommended in addition to clinical assessment as the most reliable method of confirming and monitoring correct placement of an ETT (Class I, LOE C-LD). If continuous waveform capnometry is not available, a nonwaveform CO₂ detector, esophageal detector device, or ultrasound used by an experienced operator is a reasonable alternative (Class IIa, LOE C-LD).

Reference
Part 7: Adult Advanced Cardiovascular Life Support . 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015

ResUS in the Literature: TEE Monitoring during Mechanical CPR

Demonstration of mechanical chest compressions with transesophageal echocardiography. Note the left ventricle (to the right of the image) has minimal excursion during the active compression phase.


Reference:

Giraud, R, Siegenthaler N, Schussler O, et al. The LUCAS 2 Chest Compression Device Is Not Always Efficient: An Echographic Confirmation. Annals of Emergency Medicine. January 2015

ResUS in the Literature: Monitoring CPR

Carotid Doppler Blood Flow Measurement During CPR:
A First in Man Study

Figure. Image of the left common carotid artery of subject 1. 

 Pulse-wave tracing of the artery during manual chest compressions is displayed below.

OBJECTIVE
Objective was to determine the feasibility of using ultrasound to measure blood flow on patients with cardiac arrest.

METHODS
A prospective cohort study included patients receiving ongoing manual chest compressions for cardiac arrest. Scan protocol involved physicians recording blood flow over the common carotid arteries during chest compressions with color flow and Doppler using a portable ultrasound machine. Measurements included duration of scan time, and the median values for peak systolic (PSV), end-diastolic (EDV) and mean diastolic (MDV) carotid blood flow velocities.

RESULTS
A total of 15 patients (78% of attempted) had ultrasound imaging saved. Most (n=10, 66%) had scanning times greater than 5min (median 5min 59s). Median PSV was 67cms, median EDV was 18cms, and median MDV was 14cms.

CONCLUSIONS
Ultrasound measurement of common carotid artery blood flow during CPR is feasible. Further studies are necessary to correlate carotid blood flow measures to other hemodynamic measures and its effects on patient outcomes.



Reference

Adedipe A, Fly D, Schwitz S, Jorgenson D, Duric H, Sayre M, Nichol G.
Carotid Doppler blood flow measurement during cardiopulmonary resuscitation is feasible: A first in man study. Resuscitation. 2015

ResUS Pearl: US is Highly Sensitive in Diagnosing AAA

According to a recent meta-analysis, the pooled operating characteristics of ED bedside US for the detection of AAA were sensitivity 99% and specificity 98%.

• Up to 50% of AAA patients lack the classic triad of hypotension, back pain, and pulsatile abdominal mass.

• The sensitivity of abdominal palpation for AAA increases as the diameter of the AAA increases.

• With nearly 90% mortality, and causing about 9000 deaths per year, ruptured AAA represents an important diagnostic opportunity for the use of bedside ultrasound.

Figure 1 POCUS transverse orientation of ruptured AAA

                                

Figure 2 CT of same patient demonstrating a large false lumen

References

Rubano E, Mehta N, Caputo W, et al.Systematic Review: Emergency Department Bedside Ultrasonography for Diagnosing Suspected Abdominal Aortic Aneurysm. Acad Emerg Med. 2013


Submitted by: P Maher, MD

ResUS Pearl: FAST Tip for Improving your Trauma Scan

For the RUQ view, fan through several rib spaces to see the following three things:

  1) Above and below the diaphragm

        2) Morison’s Pouch

        3)The liver tip*

*Don’t forget to scan the left side of the liver/paracolic gutter. BLOOD POOLS HERE FIRST along the inferior pole of the kidney and paracolic gutter/left border of the liver.  You may need to move your probe 1 or 2 rib spaces down from the Morison’s view to see this.

References
www.sonoguide.com

Submitted by: S Shah, MD

ResUS Pearl: Detecting decreased LVEF with E point septal separation

EPSS of >7mm is 100% sensitive and 51% specific for EF < 30% when performed by Emergency Physicians

Technique

• Obtain an M-Mode image through the tip of the mitral valve in the parasternal long axis view. 
• The distance between the maximum early opening point (the E point) and the septum is known as  E-point septal separation (EPSS). 

In a normal M-mode tracing of the mitral valve, there are two peaks during diastole. The first is the E wave, indicating early passive filling. The second is the A wave which occurs with a late diastolic atrial kick, just before  the valve closes.

Normal EPSS should be close to 0mm.

Widened EPSS (note: nonstandard orientation)

Caveats 

Patients with mitral valve abnormalties and aortic regurgitation may not have an accurate EPSS

Mitral Stenosis:

The normally appearing dip between the E and A points is gone

Aortic regurgitation:

There is fluttering of the anterior mitral valve between the E and the A peaks
from the regurgitant flow from the aorta during diastole

References

McKaigney CJ, Krantz MJ, et al.
E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction.
Am J Emerg Med. 2014

Dina Seif, Phillips Perera, Thomas Mailhot, David Riley, and Diku Mandavia.
Bedside Ultrasound in Resuscitation and the Rapid Ultrasound in Shock Protocol.
Crit Care Res Pract. 2012

Butts, C.
The Speed of Sound: Utilizing E-Point Septal Separation for Measuring Ventricular Function.
Emergency Medicine News: January 2014


Thomas Binder, MD, et al.
Interactive Echocardiography. A Clinical Atlas. Futura, 1997. via UpToDate

Submitted by: K Bryant, MD