Chapter 6

Question 1

heart rhythms associated with cardiac arrest are divided into two groups which are they ?

Answer 1

SHOCKABLE - VFIB , pulseless VTach
= first monitor rhythm in 20 percent cardiac arrest

NON- shockable rhythm - MORE COMMON = asystole and PEA

Question 2

what is the usually the next rhythm documented when resuscitations commence in asystole or PEA

Answer 2

25 PERCENT IS VFIB AND PULSELESS VTACH

Question 3

WHY SHOULD THE INTERVAL BETWEEN stopping compression and delivering shock be minimised ?

Answer 3

chance for pulse to be palpable immediately after defib - time for ROSC and palpable rhythm takes atleasst 2 min

delay in compression - further myocardium compromise - if no ROSC

if perfusing rhythm restored further chest compression has no indication of increasing the chance of VF reoccurring

chest compression can induce VF in post shock a-systole

Question 4

time taken for ROSC AND PALPABLE PULSE IS USUALLY how long

Answer 4

maybe longer than 2 mins in 25 percent of successful shocks

Question 5

what is the current evidence pointing to for the drug sequence during CPR

Answer 5

INSUFFICIENT TO SUPPORT OR REFUTE
ADRENALIE AND AMIODARONE CURRENTLY RECOMMENED BASED LARGELY ON INCREASED SHORT TERM SURVIVAL

Question 6

when there is shock refectory VF and pVTach what is important to do ?

Answer 6

to check the position and contact of defibrillates pads

considered worthwhile continued shock if patient remains in identifiable vfib or pulseless VT if you have started resuscitations - but consider changing thee pad position incase refectory to ANTERIOIR- POSTERIOr

Question 7

if a rhythm compatible with pulse i seen during 2 min cpr what should be done ?

Answer 7

do not interrupt cpr to palpate pulse unless sign of ROSC

any doubt about palpable pulse

Question 8

when can a precordial thump be used ?

Answer 8

because precordial thump has very low success rate for cardioversion of shockable rhythm

only done when :
used without delay whilst awaiting the arrival of defibrillater in MONITORED vf and vtach

Question 9

how to do precordial thump?

Answer 9

use ulnar egge of a tightly clenched fist
sharp impact on lower half of sternum from height of 20cm
retract fist immediately to create impulse like stimulus

Question 10

PROTOCOL if a patIent has monitored and witnessed cardiac arrest in CATHETER LAB , CORONARY CARE UNIT ,
CRITICAL CARE AREA
OR MONTORED AFTER CARDIAC SURGERY WHAT SHOULD BE DONE ?

Or if INTIAL RHYTHM VTACH and VFIB - AND PATIENT ALREADY CONNECTED TO MANUAL DEFIB OR IN VERY CLOSE RANGE

Answer 10

confirm cardiac arrest

shout for help

three quick successive shocks

rapid rhythm check and if appropriate pulse and OTHER SIGNS OF ROSC after each defb

start chest compression /CPR for 2 mins if third shock unsuccessful
ALSO IN THIS CASE AMIODARONE IS GIVEN AFTER THREE SHOCK ATTEMPTS

then follow ALS algorithm as if the three shock is just FIRST shock (the three shock stacked is considered to be the first shock in ALS algorithm )

ADRENALINE GIVEN AFTER ANOTHER 2 MORE SHOCK ATTEMPTS if VF and Pvtach persist

Question 11

In which type of arrest is survival unlikely unless a reversible cause can be found?

Answer 11

PEA and asystole

Question 12

Why do we avoid interruption in high quality chest compression

Answer 12

High quality chest compression and ventilation are important determinants of outcome.
Chest compression - pause causes coronary perfusion to decrease

Question 13

What depth and rate are chest compressions done

Answer 13

Depth -5-6 cm
Rate -100-120
Ensure full recoil

Soon as airway secured continue chest compression without pause during ventilation

Reduce fatigue change individual every 2 mins

Question 14

What type of ventilation preferred

Answer 14

A bag mask or SGA (supraglottic - igel) done if no person skilled tracheal tube insertion (if not skilled time taken for insertion and cannot continue CPR) - once inserted ATTEMPt to deliver continuous chest compressions

However no research shows Tracheal intubation increases survival after cardiac arrest compared with BMV and SGA

So alternatively intubation attempt can be deferred until after ROSC

Question 15

What rate do you ventilate the lungs

Answer 15

10 breaths per min

Question 16

Technique of securing ventilation when chest compression

Answer 16

Avoid stopping chest compression during laryngoscopy and intubation. Only brief pause in chest compression -if tube passed between vocal cords - pause should not exceed 5s

After intubation confirm correct tube position with waveform capnography and secure tube adequately

Question 17

How to recognise ROSC

Answer 17

Clinical signs - breathing efforts
Movement , eye opening
Require verification by Rythm and pulse check
But these can also occur without ROSC as CPR can generate sufficient circulation for consciousness

Pulse check - when ECG rythm compatible
Carotid pulsation during CPR does not necessarily indicate myocardial and cerebral perfusion
Also may not detect pulse with those of low CO

ECG - monitoring heart rythm

End tidal CO2 measured with wave form capnography

Question 18

Blood sampling and analysis problems

Answer 18

During CPR bloods taken to identify reversible causes

Avoid finger prick
Use sample from VEINS or ARTERIES
Blood gas difficult to interpret during CPR - misleading and best little relationship to tissue acid base state

Analagsis of central venous blood provide better estimation of tissue PH

Question 19

normal concentration of Pac02

Answer 19

4.7-6.0kPa

Question 20

what is end tidal Co2

Answer 20

partial pressure of co2 measured at the end of an exhaled breath - it reflexts cardiac output and pulmonary blood flow

during CPR end tiday volume is very low reflecting low cardiac output from chest compressions

Question 21

what is wave form capnography?

Answer 21

enables continuous real time end tidal c02 to be monitored during CPR - works most reliably on patient with tracheal tube - can also be used in supraglottic airway device

(OR BAG MASK?)

Question 22

uses of waveform capnography ?

Answer 22

measure quality of cpr
end tidal c02 are associated with compression depth and ventilation rate

INCREASE IN END TIDAL C02 may indicate ROSC

presence of end tidal co2 indicates the tracheal tube is in position

PROGNOSIS DURING cpr - VALUES ARE HIGHER AFTER AN INITIAL APHYXIAL ARREST AND DECLINE OVER TIME
LOW END TIDAL CO2 IS RELATED TO lower ROSC , increased mortality

Question 23

interpreting wave form capnography ?

Answer 23

inspiration - low co2
start of expiration - rapid rise of c02 (intially no c02 as it comes from anatomical dead space - ie volume of resp tract that does not take part o gas exchange the larynx , trachea , main bronchi

there is high platue stage -slight gradual increase is due to not all alveoli empty at the same rate

end of expiration conc of co2 is maximal - this is end tdal c02
healthy patients - 4.8kPa (4.3-5.5kPa)

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soon after the second defibrillation there is sa sigbnificant increase in end tidal c02 - first indicator of ROSC and OFTEN PRECEEDS OTHER INDICATORS such as pulse

IF ROSC IS SUSPECTED DURING CPR HOLD Adrenaline- Give adrenaline if cardiac arrest is confirmed in the next rhythm check

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failure to achieve an end tidal c02 greater than 1.33kPa after 20 MIN cpr associated with poor outcome

Question 24

when can CPR be stopped ?

Answer 24

COMBINATION OF CLINICAL AND PHYSIOLOGICAL SIGNS - not just by an increase in end tidal Co2
SHARP RISE IN CO2 end tidal co2
purposeful movemnet
consider breifly stopping chest compression for rhythm analysis and if appropriate pulse check
if pulse palbabale - post resus care
if NO PULSE PRESENT - CONTINUE cpr

Question 25

VASCULAR acess in resus

Answer 25

always go for peripheral lines rather than any central as this requires to stop the CPR

drugs injected peripherally needs to be FOLLOWED by a flush 20ml fluid and elevation of that extremity for 10-20s to facilitate drug delivery

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if rapid IV access if impossible consider Inter osseous route - it achieves adequate plasma concentration in a time comparable with injection through vein.
once inserted confirm correct placemnet - attempt to aspirate fom needle - presence of IO blood indicates this , but void aspiration does not imply failed attempt.

-always flush the needle
Ensure latency and observe for leakage and extravasation

Fluids and blood products can also be given IO however pressure will be needed to achieve reasonable flow rates using either a pressure bag or a syringe

Question 26

which areas are the most preferred for IO injections ?
and contraindications ?
Complications of IO

Answer 26

proximal humerus
proximal tibia
distal tibia

contra - trauma , infection , prosthesis
recent IO access in the past 48 hr , including FAILED attempts
failure to identify anatomical landmarks

Complications - extravasation and that leading to compartment syndrome
Fracture or chipping of bone during insertion

Question 27

What are the reversible causes

Answer 27

The H and T

Hypoxia ,
hypovolemia,
hyperkalemia/hypokalemia
Hypocalcemia
Hypoglycemia
Hypo/hyperthermia
Hydrogen ion - acidosis

Thrombosis
Tension pneumothorax
Tamponade
Toxins
Trauma

Question 28

How to minimise the H’s

Answer 28

Always ensure patient receives 100 percent oxygen during CPR to stop HYPOXIA - adequate chest rise and bilateral breath sounds

PEA can be caused by severe haemorrhage which can lead to hypovolemia - rapid fluid or blood needs to be given.

Hyperkalemia/hypokalemia /hypoglycaemia /hypocalcemia and other metabolic disorders can be suggested by last medical history - renal failure)

Question 29

When hyperkalemia,hypoglycaemia, calcium channel blocker overdose, is seen what should be given?

Answer 29

Intravenous calcium chloride

Question 30

Combating four T

Answer 30

Coronary thrombosis common cause.
If acute coronary syndrome is expected to be the cause of refractory cardiac arrest - can perform percutaneous coronary angiography and Conor any intervention whilst ongoing CPR
=it would require automated chest compression device

Decision to transport patient need to be assessed - realistic chance of survival are those with witnessed cardiac arrest with initial shockable rhythm (VF /pVT) and bystander CPR

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Most common cause is massive PE
Then consider fibrinolytics immediately
=survival and good neurological outcome reported
If fibrinolytic drug is given CONSIDER PERFORMING CPR for ATLEAST 60-90min before termination

When and if available - extracorporeal CPR or surgical and mechanical thrombectomy should be considered.

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Tension pneumothorax = PEA
Diagnosis - clinically of focussed US of chest
Decompress rapidly with thoracostomy of needle thoracocentesis

nsertion of a large-bore needle with a syringe, partially filled with 0.9% saline

adults : 2nd intercostal space at the midclavicular line or the 4th–5th intercostal space between the anterior and midaxillary line

and insert chest drainage

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Cardiac tamponade - difficult to diagnose
Typical distended neck veins and hypotension cannot be assessed
Focussed cardiac US during cpr can be used to diagnose pericardial effusion.

Cardiac arrest after penetrating chest trauma or after cardiac surgery should strongly raise suspicion.

Resuscitative thoracotomy

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toxins and drugs

Question 31

Why can US in advanced life suppprt be beneficial

Answer 31

Detect cardiac tamponade , pulmonary embolism , ischemia (motion wall abnormality) , aortic dissection ,pneumothorax

Requires training if we are trying to minimise interruption to CPR

Sub-xiphoid probe position is recommended

Placement of probe just before chest compression is stopped for rythm assessment and to obtain views in 10s needs a very skilled individual

Question 32

What is extracorporeal cpr?

Answer 32

Requires vascular access and a circuit with a pump and oxygen stir
This can provide a circulation of oxygenated blood to restore tissue perfusion - buy time for restoration of an adequate spontaneous circulation and treatment of reversible underlying conditions.

Evidence suggest ECPR can improove chance of survival in selected patients in where there is reversible cause for cardiac arrest( - myocardial infarction , PE, hypothermia , poisoning) ,little Co morbidity , the cardiac arrest is witnessed , individual receives high quality CPR , early implementation of ECPR and certainly within 1hr of collapse.

Individual receives high quality COR and ECPR is initiated as soon as possible

Question 33

Duration of resus attempts?

Answer 33

Team leader should discuss stopping CPR with the team.
Requires clinical judgment and careful consideration into ROSC likelihood , and LONG TERM SURVIVAL

Duration is based on the INDIVIDUAL

If it was considered appropriate to START RESUS then worthwhile to continue as long as patient in VF/pVT, or potential reversible cause

Use of mechanical compression and ECPR makes it easier for prolonged attempts at resuscitation

Generally accepted :
Asystole of more than 20 mins with no reversible cause can stop being resuscitated

Question 34

Diagnosing death after resus

Answer 34

If decision made to stop CPR
Observe patient for min 5 mins before confirming death

Absence of mechanical cardiac function
- no central pulse
-no heart sounds

Supplemented by
Continuous asystole
No pulsatile flow in intra-arterial pressure monitoring
Absence of contractile activity in echocardiography

If any return is cardiac or respiratory activity should prompt a further five min observation from the next arrest

After five min waiting the absence of pupil reflex, corneal reflex, motor response to supraorbital pressure is confirmed then death has been certified

Question 35

What are the post resus tasks?

Answer 35

Allocation of further team roles , including handover to other team

Documentation of resuscitation attempts

Communication with relatives

Post event debriefing- lead by resuscitation team leader-focuses on immediate issues and concerns

Equipment and drug trolley replenished

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