6. ALS algorithm Flashcards
2 main groups of heart rhythms associated with cardiac arrest?
shockable (VF/ pVT)
non-shockable (PEA/ asystole)
name the interventions that improve survival after cardiac arrest
1) prompt and effective bystander CPR
2) uninterrupted, high quality CPR
3) early defibrillation for VF/ pVT
(drugs and advanced airways are of secondary importance to these)
the first monitored rhythm is shockable/ non-shockable in approx 20% of cardiac arrests
shockable (VF/ pVT)
placement of defib pads?
below the right clavicle
V6 position, midaxillary line
next step after confirming the rhythm is VF/ pVT?
resume chest compression immediately, warn all other than the chest compressor to ‘stand clear’ and remove any oxygen devices
select the appropriate energy on the defibrillator and press charge
what energy setting should you choose for the first shock?
120 to 150 J (the same or higher for subsequent shocks)
T/F: after delivering the shock, continue to pause compressions to feel for a pulse
false - immediately restart CPR in 30:2 ratio starting with compressions
how long between rhythm checks?
2 minutes
when to give drugs and what drugs to give
after 3rd shock,
give intravenous 1mg 1:10,000 adrenaline and 300mg amiodarone at the next rhythm check (in 2 mins)
how often and how much adrenaline should be given?
1mg of 1:10,000
after 3rd shock then every alternate shock thereafter (3-5 mins approx)
T/F: the time between ROSC and return of a palpable pulse is typically < few seconds
false - can take up to 2 minutes
do not delay restarting chest compressions in order to check pulse
T/F: if a perfusing rhythm has been restored, giving chest compressions increases the chance of VF recurring
false!
how often and how much amiodarone should be given?
after 3rd shock - 300mg IV
if VF/ pVT persists or recurs, a further dose may be given after a total of 5 defibrillation attempts - 150mg IV
alternative if amiodarone is not available?
lidocaine 1mg/kg
do not give if amiodarone has been given already
what can be done to the pads in refractory VF/ pVT?
consider changing pad position e.g. to anterior-posterior
T/F: if a rhythm compatible with a pulse is seen during a 2 min period of CPR, stop to palpate the pulse
false - unless the pt shows signs of life suggesting ROSC
Are precordial thumps routinely recommended?
no - very low success rate for cardioversion of a shockable rhythm
only use if can be used without delay whilst awaiting the arrival of a defibrillator in a monitored VF/pVT arrest
how to carry out a precordial thump?
deliver sharp impact to lower half of sternum using ulnar edge of tightly clenched first from height of 20cmT
T/F: there is a very high chance of ROSC when defibrillation occurs immediately after the onset of VF/ pVT
true- hence why 3 stacked shocks recommended when these arrests occur in monitored environments
If the initial 3 stacked shocks method is used (ie in a monitored environment), when should the first dose of ADRENALINE be administered?
after 2 more subsequent shocks (the 3 initial shocks are treated as the first shock in the ALS algorithm)
If the initial 3 stacked shocks method is used (ie in a monitored environment), when should the first dose of AMIODARONE be administered?
during the 2 min of CPR after the 3 stacked-shock attempts
PEA is cardiac arrest in the present of electrical activity (other than ___ ___) that would normally be associated with a palpable pulse
ventricular tachyarrhythmia
Whenever a diagnosis of systole is made, check the ECG carefully for the presence of P waves - why?
because in this situation, ventricular standstill may be treated effectively by cardiac pacing
treatment algorithm for PEA and asystole?
start CPR 30:2
give adrenaline 1mg IV soon as IV access achieved
recheck rhythm after 2 mins: if electrical activity compatible with a pulse is seen, check for pulse/ signs of life
if none, continue CPR giving further adrenaline every alternate 2 minute cycle
change to shockable algorithm if VF/ pVT seen at a rhythm check
T/F: if VF is seen on the monitor during the break for ventilations (rather than at the end of the 2 min cycle), administer the shock then before waiting for the end of the 2 min cycle
False - still wait until the end of the 2 min cycle
Airway equipment to be used in the absence of someone skilled in tracheal intubation?
bag-mask, or preferably, a supraglottic airway (e.g. i-gel)
T/F: once a supraglottic airway has been inserted, you can attempt to deliver continuous chest compressions, uninterrupted during ventilation
True - you can ventilate the lungs at 10 breaths a minute (monitor to check for excessive gas leakage that may cause inadequate ventilation - if so interrupt compression to enable ventilation)
T/F: studies have shown tracheal intubation increases survival after cardiac arrest
false - nil evidence to show it increases survival compared with BMV or use of an SGA
furthermore long pauses in chest compression or incorrect placement of the tube is common in arrest if intubation is attempted by unskilled personnel
T/F: you should avoid stopping chest compressions during laryngoscopy and intubation if possible
true - if necessary there can be a brief pause as the tube is passed between the vocal cords but that should not exceed 5s
after intubation, how should correct tube position be confirmed?
with waveform capnography
a pulse that is felt in the femoral triangle during CPR can indicate ___ rather than arterial blood flow
venous
T/F: during cardiac arrest, ABGs are of limited value
true - may be misleading and bear little relationship to the tissue acid-base state (central venous blood better)
normal PaCO2? (concentration of CO2 in arterial blood)
5.3
the partial pressure of CO2 at the end of an exhaled breath is called what?
end-tidal CO2
what is end-tidal CO2 a reflection of?
cardiac output, pulmonary blood flow and the ventilation minute volume
name some of the roles of waveform capnography during CPR
- ensure tracheal tube placement
- monitoring ventilation rate
- monitoring chest compression quality
- identifying ROSC
- prognostication
on waveform capnography what does
1) the first upstroke bit
2) the plateau
3) the last downstroke bit
represent?
1) start of expiration
2) alveolar plateau as gas from alveoli take part in gas exchange
3) the end of expiration
what is the normal end-tidal CO2 in health patients?
4.8
rate of ventilation during CPR? (once tracheal tube/ secure SGA has been secured)
10/ min
T/F: if ROSC is suspected during CPR, withhold adrenaline
true - then give if cardiac arrest is confirmed at the next rhythm check
T/F: failure to achieve an end-tidal CO2 > 1.33 after 20 mins CPR should indicate that efforts should be stopped
false - is a poor prognostic indicator but shouldn’t be used on its own to stop CPR efforts
3 main insertion sites for IO?
proximal humerus, proximal tibia and distal tibia
contraindications to IO?
trauma, infection, a prosthesis at the target sitec, or recent IO access in the past 48 hours in the same limb
complications of IO?
extravasation into the soft tissues, dislodgement of the needle, compartment syndrome due to extravasation, fracture/ chipping of the bone, pain related to the infusion or drugs/ fluid, fat emboli, infection/ osteomyelitis
reversible causes of cardiac arrest?
hypoxia
hypovolaemia
hyper/hypo-kalaemia/ hypoglycaemia/ calcaemia / metabolic
hypothermia
thrombosis (coronary/ pulmonary)
tension pneumothorax
tamponade (cardiac)
toxins
When might IV calcium chloride be given in cardiac arrest?
hyperkalaemia
hypocalcaemia
calclium channel-blocker overdose
commonest cause of thromboembolic or mechanical circulatory obstruction?
massive PE
if a fibrinolytic drug is given for suspected PE arrest, continue CPR for at least how long?
at least 60-90 minutes
how to suspect and manage cardiac tamponade as the cause for an arrest?
focussed cardiac ultrasound can show a pericardial effusion
have strong suspicion if arrest after penetrating chest trauma/ post-cardiac surgery
consider resuscitative thoracotomy
If CPR is successful and a decision is made to discontinue efforts, the patient should be observed for at least how long before confirming death?
5 minutes
