ECG and Patient Monitoring

Question 1

What are some examples of emergency care devices ?

Answer 1

External Defibrillators
Automatic Chest Compressors
Emergency ventilators
Manual resuscitators
Multi-parameter monitors

Question 1

What is the difference between emergency and intensive care ?

Answer 1

Emergency care is medical attention given to someone who has had a life threatening accident or illness
Intensive care is when someone requires intensive treatment.

Question 2

What components does an external defibrillator contain?

Answer 2

A power supply
A switch between charge, standby and discharge states
Capacitive Energy storage
Timing Circuitry
An ECG monitor
Plates for discharge

Question 3

What are the values for pulse width, patient resistance and shock voltage for defibrillators?

Answer 3

Patient Resistance = 50-100 ohms
pulse width = 10ms
shock voltage = 750-800 Volts

Question 4

What are monophasic and biphasic waveforms for defibrillation ?

Answer 4

Monophasic - waveform only delivers energy in one direction
Biphasic - energy is delivered in both directions.

Question 5

What are the precautions and risks associated with an external defibrillator ?

Answer 5

Precautions :Applying gel and ensuring the patient doesn’t have an internal pacemaker
Risk: Cardiac muscle injury, blood clots and skin burns.

Question 6

How are external defibrillators checked ?

Answer 6

Visual checks of attachments on paddles and leads.
Battery/ AC power checks
Electrodes and adaptor cables
Recorder and paper roll check
Energy select settings

Question 7

What does a manual resuscitator do ?

Answer 7

Provides ventilation with highly oxygenated air when ventilation is unavailable.

Question 8

What are some examples of parameters measured by a patient monitoring system ?

Answer 8

ECG
Oxygen Saturation
NIBP
Respiration Rate
Temperature
CO2 concentrations

Question 9

How does O2 saturation monitoring work?

Answer 9

Shining infrared and red light on oxyhaemoglobin and deoxyhaemoglobin has different absorption responses. O2 saturation measures the percentage of oxyhaemoglobin

Question 10

How does NIBP (Non-invasive blood pressure) work?

Answer 10

Blood pressure cuff inflates to above the systolic pressure and then deflates to below the diastolic pressure. Systolic when first beats are heard and diastolic is the lowest pressure where a beat can still be heard.

Question 11

How does end tidal capnography work ?

Answer 11

Uses infrared to determine the CO2 concentration within the blood. CO2 absorbs light at roughly 4.28 micro metres of wavelength. Monochromatic IR source is used.

Question 12

What is an ECG/EKG ?

Answer 12

The recording of the electrical activity across the heart over time.

Question 13

What are the types of ECG lead configurations and what are they used for ?

Answer 13

12 lead - Used to diagnose dysrhythmias, myocardial infarction or conduction abnormalities.
5 lead - emergency departments and ICUs.
3 lead - Basic cardiac monitoring.

Question 14

What preparations must be considered before undergoing an ECG ?

Answer 14

Removal of all jewellery and ensuring no medication has been taken. Also, cleaning of the skin and avoid wearing skin lotions which may impact the skins conductivity.

Question 15

What tests must be done to ensure proper ECG functioning ?

Answer 15

Lead Fail tests.
Noise tests.
ECG waveform tests.
LCD tests.

Question 16

Briefly explain the electrical conduction system of the heart

Answer 16

Pacemaker cells in the SA node begin depolarisation. This spreads through the atrium until it reaches the AV node in the cardiac wall. The depolarisation then spreads down to the bundle of His. It then splits into left and right bundles before reaching the purkinje fibres at the bottom of the heart.