Defibrillators WHO Defibrillator External Automated Semiautomated From the

Defibrillators WHO. “Defibrillator, External, Automated; Semiautomated. ” From the publication: Core Medical Equipment. Geneva, Switzerland, 2011.

Summary • • • Quiz Clinical Use History Specifications Principles of Operation Block Diagram • Commercial Examples • Preventive Maintenance • Common Problems • Test Procedures

Quiz 1. What is the 2 main clinical cases that require the use of defibrillator? 2. What are the different types of defibrillator? 3. What is the defibrillator waveform polarity? 4. Does one need to use gel? Why?

Quiz 5. What kind of paddles can be used? 6. Draw the 2 possible of paddles placement in the case of external electrodes. 7. Can one use a defibrillator with a patient on a OR table? Why? 8. What are 2 ways to test a defibrillator 9. What is the most common problem in defibrillators from the developing world?

Fibrillation • Cardiac arrest occurs in more than 500, 000 people annually in the United States • Atrial fibrillation (AF) is relatively common and can be well tolerated by the patient

Fibrillation Jer 5150 (2012) Fibrillation [Image], retrieved from https: //commons. wikimedia. org/wiki/File: Ventricular_fibrillation. png

Ventricular Fibrillation • Ventricular fibrillation (VF) causes the heart to stop pumping blood immediately • Irreversible brain damage or death after 5 minutes • Most common cause of death

Clinical Use • Reverse fibrillation of the heart (300 J to 360 J) [Drawing of defibrillator pads placement] retrieved from www. wikipedia. com • Restoring the heart’s normally coordinated contractions (below 200 J) – Requires ECG

History • 1899 – Physiologists Prevost and Batelli from University of Geneva used small electric shocks to induce ventricular fibrillation in dogs, and larger charges to reverse the condition

History • 1947 –First use on a human by Claude Beck, professor of surgery at Case Western Reserve University

Specifications • Input – Electrical: ECG signal • Output – Electrical: 3000 V pulse during 10 ms – Electronically (display) Philipp. N, (November 2007), Position of Electrodes during Defibrillation, retrieved from https: //commons. wikimedia. org/wiki/File: De fibrillation_Electrode_Position. jpg

Principles of Operation • Electric current is placed through electrodes: – Directly on the heart - low current – 300 V AC. – Transthoracically – large area electrodes, higher current – 1000 V AC [Photograph of defribrilator] retrieved from www. wikipedia. com

Types of Defibrillators • Manual defibrillator (most common in developing world) • Automated external defibrillators AED (Home defibrillator) WHO. “Defibrillator, External, Automated; Semiautomated. ” From the publication: Core Medical Equipment. Geneva, Switzerland, 2011. • Implantable defibrillator Steven Rodriquez (2007), Defibrillator [photograph], retrieved from https: //www. flickr. com/photos/n 28 ive 1/431939091

Output Pulses • Edmark Waveform – Maximum Pulse 7, 500 V – Common in the poor world – Severe damage (death) – Be clear of the patient during the discharge vp 2 kv ~10 ms Virginia Reid (2015), Waveform [drawing]

Output Pulses Virginia Reid (2015), Output Pulses, [drawing] Monophasic truncated exponential Biphasic truncated exponential Safest Waveform

Manual Defibrillators ECG • ECG leads can also be connected from the device to the patient • However, most can monitor the ECG through the defibrillation paddles as well. Aededitor (2011), Semi-automated external monitor defibrillator [photograph], retrieved from https: //commons. wikimedia. org/wiki/File: Semi-automated-externalmonitor-defibrillator. jpg

Synchronization Shock point Husche (2015), ECG Figure EN [diagram]. Adapted from https: //commons. wikimedia. org/wiki/File: CCM_ECG_Figure_EN. png

ECG Synchronization Anthony Atkielski (2012), Sinus Rhythm Labels [diagram]. Retrieved from https: //commons. wikimedia. org/wiki/File: Sinus. Rhythm. Labels_fi. svg

Paddles • Excellent contact with the body is essential – Gel required – Serious burns can occur if proper contact is not maintained during discharge • Sufficient insulation is required – Prevents discharge into the physician

Paddles Types • Internal: direct cardiac stimulation • External: transthoracic stimulation – Adult – Pediatric • Disposable: used externally

Paddles Types • Disposable • Internal • External Yury Masloboev (2007), Defibrillator, [photograph]. Retrieved from https: //commons. wikimedia. org/wiki/File: Defibrillator_(UOMZ). jpg

Paddles Position DHTLab (2015), Defibrilator Packet, retrieved from BMET Library

Paddles Position Owain Davies (2012), Defib electrode placement, retrieved from https: //commons. wikimedia. org/wiki/File: Defib_electrode_placement. png

Schematics Openstax College. “Cardiac Muscle and Electrical Activity. ” From the publication: Biology. Rice University: 2013.

Internal (Implantable) Defibrillator Bruce. Blaus (2013), Implantable Cardioverter Defibrilator [diagram]. Retrieved from https: //commons. wikimedia. org/wiki/File: Blausen_0543_Implantable. Cardioverter. Defibrillator_Inside. Leads. png

Commercial Examples External Defibrillator Openstax College. “Cardiac Muscle and Electrical Activity. ” From the publication: Biology. Rice University: 2013.

Commercial Examples Internal Defibrillator Steven Rodriquez (2007), Defibrillator [photograph], retrieved from https: //www. flickr. com/photos/n 28 ive 1/431939091 Gregory Marcus (2008) Implantable cardioverter defibrillator chest X-ray [photograph] retrieved from https: //commons. wikimedia. org/wiki/File: Implantable_cardioverter_defibrill ator_chest_X-ray. jpg

Commercial Examples AED Wikipedia. “Automated External Defibrillator. ” Wikipedia, p. 1 -5. Retrieved from: https: //en. wikipedia. org/wiki/Automated_external_def ibrillator

Safety • Avoid conducting mattress (spring), bedstead or metal table • Wear surgeon’s rubber gloves with highvoltage insulation • CAUTION: high current and voltage associated with the circuitry. • Use GEL Werneuchen (2008) Surgical Gloves [photograph]. Retrieved from https: //commons. wikimedia. org/wiki/File: Surgical_glov es_26. JPG

Preventive Maintenance • Replaced battery every 24 months • Defibrillators offer a selftest option which should be done at least once a month

Common Problems • Old Batteries • Paddles and cables contact • The gel build up on the paddles and have to be cleaned with alcohol

Test Procedures • Paddles should be inspected for pit marks • They could leave burns on the chest

Test Procedures • Defribillator Selftest • Use a fresh meat (normally pig) NEVER TEST THE PADDLES AGAINST EACH OTHER!

Questions ?

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