Introduction to Paramedic Practice - Week 1 + 2 (Cardiac arrest, communication, vital signs + Primary survey and infection control) Flashcards
(97 cards)
WEEK 1 - Cardiac arrest, communication and vital signs
Resus theory - What is a cardiac arrest?
The cessation of effective cardiac output (Which is the amount of blood pumped around the body every minute). This means the patient’s heart has stopped, and is clinically ‘dead’.
Cardiac arrest - NOTES (resus theory)
- A patient without a heart beat does not move blood and oxygen around the body
- This means tissues become hypoxic and begin to die
- The longer tissues go without oxygen the more cells will die
- The longer it takes to restart a heart the worse the patients prognosis will be
Resus Theory- What signs might indicate a cardiac arrest?
- Bystanders doing CPR
- A pale or grey patient
- Central cyanosis (bluish colour due to lack of oxygen)
Resus Theory - What does the ‘Thoracic pump theory’ describe?
- When you do CPR you aim to compress the chest by a third with every compression
- If you decrease the volume of the chest cavity you increase the pressure.
- That means the pressure on the heart increases forcing blood out the heart into circulation.
- Your circulatory system only flows one way – that how its built and you’ll cover it in human body systems
- When you release the compression the pressure returns to normal but now there is no blood filling the heart- so blood is drawn into the heart to fill the space: ready for the next compression.
Resus Theory - What does the ‘Cardiac pump theory’ refer to?
- The heart is located between the spine and the sternum
- As you perform compressions you press the sternum towards the spine, consequently the heart is compressed between the two structures.
As the heart gets compressed blood gets forced out and as you release the compression the heart refills. - Remember it’s a one way system.
- Current thinking is that both mechanisms (this and thoracic pump theory) probably contribute to effective CPR
Resus theory - Concept - Vectors: Notes
Force is a vector: it has both a magnitude and a direction
Contrast to a scaler such as height or speed
Adding vectors: Force in the same direction
Adding vectors Force in two directions
Resus Theory - Application: Compressions:
First of all, arms straight and lock your elbows or you end up using your biceps and triceps too.
If you align your shoulders over the patient the force you apply goes directly down, into their sternum. You pivot on your hips.
As a bonus you get to add the weight of your own toros and shoulders to the compression meaning you don’t have to work as hard.
If you don’t align your shoulders above the torso, the force goes in at an angle, you don’t get the full benefit from your own body weight and you have to use more of your arm muscles to compensate. This gets tiring after a while and your compression quality starts to suffer.
Resus Theory: Application (compressions) Does it even matter?
CPR is mainly performed by flexion and extension through the hip joint.
If you are not positioned properly you are not able to utilize some of your major muscle groups. If your not over the patient you cant engage your pectoralis major.
If you are kneeling too far back you don’t get to use your legs or your core.
Its not that you cant still do effective compressions, you can but you will tire more quickly and all the power has to come from your arms.
It takes about 30kg of pressure to compress a chest. As you tire your compressions become ineffective.
Resus Theory: Concept: Rate of compressions
NZ resuscitation council recommends between 100 and 120 beats per minute. This is based on how many people survive out of hospital cardiac arrest and what rate seems to offer the best chance
We teach 110 beats per minute, right in the middle of that range. If you add one extra or skip one that gives you a little wiggle room rather than sitting on one extreme or another
Resus theory - What is the acceptable depth of compressions?
5cm, or about 1/3 of the thoracic cavity
Resus theory - Normal sinus rhythm: NOTES
Normal pathway of the electrical impulse
Originates in the Sino Atrial (SA) node
Intrinsic rate of 60-100 beats per minute
Do not defibrillate
(P wave, QRS complex, T wave)
Resus Theory - Cardiac arrest arrythmias: What are the four arryhthmias focussed on in 1st year paramedicine?
- Ventricular Tachycardia (VT)
- Ventricular Fibrillation
- Pulseless Electrical Activity (PEA)
- Asystole
Resus Theory - Cardiac arrest arrythmias: Ventricular tachycardia:
Shark tooth appearance
Fast heart rate (originates in the ventricles, not the atria)
Treatment; defibrillation
Resus Theory - Cardiac arrest arrythmias:
Pulseless electrical activity:
Organised electrical activity with no detectable output
Do not defibrillate – The electrical activity is already working normally even though there is no cardiac output.
Treatment: look for and treat reversible causes
Resus Theory - Cardiac arrest arrythmias:
Pulseless electrical activity:
What is the only way to differentiate a normal sinus rhythm from PEA?
To see if you can palpate a pulse (usually carotid or femoral). In the absence of a pulse, you know you are working with PEA over normal sinus rhythm.
Resus Theory - Cardiac arrest arrythmias:
Asystole:
Complete absence of electrical activity (no pulse)
Poor prognosis
Do not defibrillate – This rhythm has no electrical activity, defibrillation will have no effect
Treatment: look for and treat reversible causes
Resus Theory - What are the reversible causes of a cardiac arrest (4H’s and 4T’s)?
- Toxins
- Tension pneumothorax (air in pleural space)
- Thrombosis (blood clot in vessel)
- Tamponade (compression of heart due to blood/fluid in heart cavity/pericardial space)
- Hypoxia (lack of oxygen)
- Hypokalemia (potassium based)
- Hypo/erthermia (temp)
- Hypovolemia (volume of blood in circulation)
Resus Theory - Primary vs Secondary Arrest:
What is a primary cardiac arrest?
When the heart stops beating due to a mechanical or electrical failure of the heart. A heart attack or dysrhythmia causing cardiac arrest would be examples of primary cardiac arrest
Resus theory - Primary vs Secondary arrest:
What is a secondary cardiac arrest?
Any non-cardiac problem which causes the heart to cease functioning is a secondary cardiac arrest. If a person drowns or chokes or asphyxiates, they will be unable to inspire oxygen. A lack of oxygen will cause a lack of ATP which will eventually cause the heart to stop beating. Stabbings, poisonings and drownings are all examples of secondary cardiac arrest
Resus Theory - Primary Vs Secondary arrest:
Additional NOTES
Primary Arrest
- Cardiac Cause
- Priority is defibrillation and compressions
- Ratio of 30:2
Secondary Arrest
- Non – Cardiac Cause
- Priority is ventilations
- Look for reversable causes
- Ratio of 15:2
Resus Theory - Cardiac arrest
- ‘Pit crew’ approach:
Use defined roles
Team leader
Airway/ breathing clinician
Chest compressions
Clear communication
Flattened hierarchy
What are the three overt signs of a cardiac arrest?
- Unconscious
- Abnormal or NO breathing
- Absence in signs of circulation (central cyanosis or pale/grey in colour)
What is the average amount of blood pumped around the body per minute (at rest)?
5 litres a minute
Vital signs: Respiratory rate - What is respiratory rate?
The amount of times someone breathes in one minute