CPR Flashcards
Compressions
100bpm 1/3-1/2 width of thorax swap q2min lateral if keel, dorsal if barrel (bulldog) <10kg over heart, >15kg widest chest
Steps at CPA
- Check for heart beat
- Start compressions
- Someone else checks airways - patency, intubate - ventilate
- ALS
Ventilation
10bpm
<30cm H2O
TV = 10ml/kg
Aim ETCO2 >15mmHg
NAVEL drugs?
Naloxone Atropine Vasopressin Epinephrine Lidocaine
Intraosseous sites
- proximal humerus
- intertrochanteric fossa of prox. femur
- tibial tuberosity
- wing of iliac
MOA of atropine
anticholinergic drug that binds to and antagonises muscarinic cholinergic receptors, leading to w/drawal of parasymp. stim.
atropine dose in CPA
0.04mg/kg q3-5min
MOA of epinephrine
a sympathomimetic drug that binds to and antagonises the alpha and beta adrenergic receptors
Alpha – vasoconstriction
Beta - chrono + inotrope
epinephrine dose
0.01mg/kg q3-5min
Vasopressin MOA
non-adrenergic vasopressor that binds to and agonises the V1A receptor on vasc. smooth muscle causing vasoconstriction
advantage of vasopressin over epinephrine
functions better in acidic environments (CPA often acidic environment dt lack of tissue perfusion)
opioid reversal
naloxone
dexmedetomidine, medetomidine reversal
atipamezole
xylazine reversal
yohimbine
benzos reversal
flumazenil
Amiodarone MOA
potassium channel blocker used to tx patients w/ a perfusing ventricular arrhythmias, defibrillation resistant pulseless ventricular tach/fib
Lidocaine MOA
class 1b antiarrhythmic –> sodium channel blocker to tx. pulse ventricular tachy/fibs
indications to use calcium gluconate
IF there is documented ionized hypocalcaemia OR documented hyperkalaemia during CPR resulting from poor tissue perfusion + subsequent cell death
indications to use sodium bicarbonate
only if severe metabolic acidosis prior to CPA
a large spike in end-tidal CO2 is indicative of…
ROSC
> 20mmHg ETCO2 in cats indicates..
adequate chest compressions in closed chest CPR
> 15mmHg in dogs indicates…
adequate chest compressions in close-chest CPR
How do you use an ECG during CPR?
leads places, compressions stopped for <10sec every 2min to allow interpretation of heart rhythm
what is the goal of electrical defibrillation?
depolarise all of myocardial tissue simultaneously to achieve asystole in hope that a pacemaker cell will take over to generate a perfusing rhythm
when is electrical defibrillation indicated?
pulseless ventricular tachy/fibrillation are the only pulseless rhythms that should be treated w/ electrical defib ASAP once IDed
what dose of fluids is recommended during CPA?
a full shock dose (unless arrested dt congestive heart failure)
Myocardial perfusion is dictated by…
perfusion pressure (CoPP) = the difference between the pressure at the starting point in the aortic sinus (DAP = diastolic aortic pressure) and the pressure at the finishing point (RAP = right atrial pressure)
CoPP =
DAP - RAP
CoPP >/= (???) in order to achieve ROSC
25mmHg
describe the thoracic pump theory
> 15kg animals - when pressure is applied to the widest part of the thoracic cavity, intrathoracic pressure is maximally increased forcing blood w/in the large vessels either out of the thorax via the aorta, or up to and through the heart via the intrathoracic CV. Valves w/in veins prevent backward flux of blood out of the thorax. Chest recoil post compression causes pressure w/in thorax to decrease, opening large vessels and allowing them to fill w/ blood from extra-thoracic space.
describe the cardiac pump theory
<10kg animals - blood flow during chest compression where the hand is directly over the heart, is dt compression of the ventricles btwn the lateral chest walls (in lateral recumbency) or btwn the sternum and spine (in dorsal)
how is the preload provided for next cardiac cycle in CPR?
after the compression, chest recoil occurs as ribs return to normal anatomic position –> creates low pressure region w/in thorax drawing blood to fill the heart and great veins –> provides preload for next cardiac cycle
what are the risks of hyperventilating a patient during CPR?
decreased venous return and preload, decreased CO and compromised CoPP and decreased ROSC/survival dt persistent positive pressure on the thorax
explain the theory of interposed abdominal compressions
- performed by 2 people - abdominal and chest compression alternatively
- increases abdominal pressure during diastole forces abdominal aortic blood cranially towards the aortic sinus –> inc DAP –> inc CoPP
- inc. CO by improving venous return to heart via compression of CdVC
- -> v. technically challenging
why might the application of constant pressure to the abdomen be beneficial in CPR?
= abdominal counterpressure
- may improve blood flow through cranial body by decreasing blood flow through abdominal aorta
when is it reasonable to stop CPR?
after 20-30mins w/ no ROSC
Characteristics of pulseless electrical activity on ECG?
- coordinated electrical activity/repeats
- rates <200bpm (commonly <50bpm)
- narrow QRS complexes commonly (but can look like normal sinus rhythm or have wide/bizarre complexes)
characteristics of asystole on ECG?
- no electrical activity/flat line
name the two common non-shockable rhythms
- PEA
- Asystole
name the two common shockable rhythms
- pulseless VTach
- VFib
characteristics of pulseless VTach?
- organised, rpt, wide QRS complexes
- >200bpm w/out accompanying pulses
characteristics of Vfib?
- wavy, chaotic line (lack of consistent, rpt waveform)
- fine (low amp, high freq) vs. coarse (high amp, low freq)
