New and Future Trends in EMS. Ron Brown, MD, FACEP Paramedic Lecture Series 2018

Transcription

1 New and Future Trends in EMS Ron Brown, MD, FACEP Paramedic Lecture Series 2018

2 New technologies and protocols DSD Mechanical Compression ITD BiPAP Ultrasound

3 Double Sequential Defibrillation Two defibrillators delivering non-synchronous shocks closely spaced Believed that the differing vectors, rather than increased energy or area of myocardium covered, is what provides benefit Decades old use by cardiology for cardioversion in refractory Afib EMS usage: refractory VF defibrillation

4 Sequential as opposed to simultaneous theoretically does two things: Prevents cancelling the vector wave Prevents electricity from one unit damaging the circuit board of the second Unknowns: Ideal pad placement Ideal timing Risk to equipment Officially off-label Need to run and document maintenance check afterward

5 AP & A-apex

6 Mechanical Compression Devices Concept goes back decades Consistently found to not be superior to human compressions (CIRC, LINC) Piston type (LUCAS) Load distributing band (AutoPulse) Device position is crucial

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9 Autopulse vs Lucas vs manual CPR Found that piston devices (Lucas) did not result in more visceral injury than manual CPR Found that compression band (Autopulse) induced increase in visceral injury could not be excluded

10 When to use?

11 mcpr Indications During transport Restrictive environment: helicopters, small fixed wing EMS personnel safety in moving rig Refractory VF Transport to CVL without ROSC Post-ROSC Apply prior to initiating transport Recurrent arrest

12 Impedance Threshold Device Use during CPR, meant to decrease intrathoracic pressure, thereby increasing venous return Restricts inflow of air into chest during recoil phase* Animal models showed increased perfusion to brain and heart Current randomized trials do not show improved ROSC or neurological outcome in clinical medicine Latest meta-analysis (2015) Latest animal models continue to show improved hemodynamics (2014)

13 Hypothesis and Data

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16 Noninvasive Positive Pressure Ventilation Continuous Positive Airway Pressure is commonly used Requires spontaneous ventilations and airway protection Helps increase diameter of dead space airway, recruit alveoli. Increased Functional Residual Capacity Decreases venous return good for pulmonary edema Ventilatory support traditionally requires BVM or a tracheal airway + bag

17 IPPV vs NPPV NPPV requires airway protection by the patient Spontaneous respirations Adequate mental status IPPV (e.g. ETT + ventilator) requires no patient effort Airway protection (never 100%) No diaphragm or accessory muscle use needed

18 Downside IPPV Increased morbidity and mortality Increased risk of aspiration Increased virulence of pathogens in CCU Mechanical path from CCU atmosphere into trachea Deconditioning of respiratory muscles Required use of sedation: iatrogenic encephalopathy

19 NPPV: BiPAP Bilevel Positive Airway Pressure: CPAP + increased pressure when ventilator senses a drop in system pressure as the patient initiates inhalation So, does require some use of negative pressure (normal) respiration Improves airway diameter, alveolar recruitment, preload reduction Pressure Support during a breath increases these parameters Greater oxygen delivery Increased mixing of carbon dioxide, and exhalation as PS decreases to PEEP, CO2 richer air exits the chest Marked improvement in hypercapneic encephalopathy

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22 Pressure Support vs Assist Control PS relies on intact ventilation AC (also called CMV continuous mechanical ventilation) sets a tidal volume and rate (thus the minute volume)

23 Zoll AEV, EMV+ Ventilators combining traditional ETT modes with CPAP and BiPAP Can be set in Assist Control, most likely used in BL (Pressure Support)

24 Ultrasound in EMS Ultrasound use is expanding markedly beyond use by Radiology Nursing: difficult peripheral vascular access Emergency medicine: vascular access, FAST for trauma, guidance for various aspiration procedures (paracentesis, arthrocentesis, thoracentesis), abscess evaluation, pneumothorax evaluation, cardiac evaluation (particularly arrest situations) Critical care medicine Trauma surgery

25 Possible Prehospital Uses Detection of pneumothorax belay that dart! Cardiac Visualization of cardiac activity in termination of resuscitation Cardiac tamponade AAA Vascular access Downgrades

26 Possible Prehospital Uses Detection of pneumothorax belay that dart! Cardiac Visualization of cardiac activity in termination of resuscitation Cardiac tamponade AAA Vascular access Downgrades not really

27 Pneumothorax Detecting : Ultrasound: sensitivity 86-98%, specificity % AP CXR: sensitivity 28-75%, specificity 100%

28 Cardiac Activity

29 Tamponade

30 AAA

31 IV Access

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33 Barriers to Prehospital Ultrasound Cost Unit + probes Three types of probes but can get by with two Typically probes are $8,000 each Expertise Training

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