cardiac arrest & intraop myocardial ischaemia Flashcards
What’s the adult rate of compressions for CPR?
100-120/minute
On the shockable cardiac arrest algorithm, after the first (300mg) amiodarone dose, what are subsequent doses of amiodarone?
150mg (? this may be old.. followed by an infusion of 900mg over 24hrs)
What’s the first step in any crisis?
Simultaneous actions of communicating the problem (w appropriate level of urgency) to surgeons & team, calling for help & delegating tasks
What level of hyperglycaemia should be treated during post-resus care?
> 10mmol/L
What should the sats be during post resus care?
94-98% (avoid hyperoxia)
What are the 4H’s 4HT’s reversible causes of cardiac arrest?
Hypoxia Hypovolaemia Hypothermia Hypo/hyperkalemia Thrombus Toxins Tamponade Tension PTx
What transthoracic echo view is useful during cardiac arrest? When should US (which may help diagnosis) be used?
Sub-xyphoid
During the brief pause for rhythm check (interruptions to CPR only <5secs)
What’s the rate of ventilation during cardiac arrest?
10/minute
What’s the goal maximum time for interruption between chest compressions?
<5secs
What’s energy for biphasic shock during cardiac arrest? Monophasic? Kids?
200J, 360J, 4J/kg
When should the drugs be given in cardiac arrest wrt defibrillation?
immediately after
When are “stacked” shocks used? How many?
Up to 3 in a row, for witnessed VF/VT when defibrillator pads in situ (eg. after cardiac surg, in Cath lab, crit care environment)
What’s the dose of Mg++ given for torsades or hypomagnesemia?
1-2g IV over 3 mins
What’s the dose of Ca++ for hyperkalemia, hypocalcemia or OD of calcium channel blockers?
CaCl 10% IV 10mL
What’s the dose of sodium bicarbonate for hyperkalemia or antidepressant overdose?
1-2mL/kg 8.4% IV
How much adrenaline is given immediately (after commencing compressions) for non-shockable cardiac arrest? How often is it then given?
1mg IV
Every alternate cycle of CPR
For what type of non-shockable cardiac arrest should pacing be considered?
Asystole w p waves present
What are the roles which should be delegated in cardiac arrest?
Team leader
Compressions (alternate each rhythm check or as needed- quality of CPR vital)
Airway/ventilation
Defib & monitoring cardiac monitors
Time prompts & scribing
Drugs/access/samples/runner for 4Hs & 4T’s
-many hands useful ++
What is a strong differential with PEA in surgical setting?
Other considerations?
hypovolaemia due to undiagnosed haemorrhage, esp w laparoscopic surgery
Other differentials include high spinal & anaphylaxis
What’s the goal for fluids during cardiac arrest?
Normovolaemia
Unless hypovolemic, avoid excessive fluid
What’s an ideal confirmation when placing an airway?
Confirm correct placement w CO2 detection
What are the steps for paediatric ALS?
- Check pulse, oxygenation & confirm ecg rhythm
- Stop all vagal stimulation & switch to 100% O2
- Call for help, communicate & delegate
- Start CPR 100-120/min
- If VF/VT, give shock 4J/kg
- If asystole/PEA, given Adr 10mcg/kg IV
- Stop agent & consider intubation by most experienced operator (confirm w capnography) @ next rhythm check
- review 4Hs/Ts
- check rhythm/output @ CPR changeover
- consider TTE during brief (<5s) CPR interruption
- give Adr every 2nd cycle
- activate ECMO @ our institution (trained teams & protocols)
What’s the dose of adrenaline for Paediatric ALS non-shockable? Frequency?
10mcg/kg- for PEA & asystole, give immediately, then every 2nd loop (every 2mins)
With the exception of cardiac anaesthesia, what’s the rhythm for most anaesthetic-related paediatric cardiac arrests?
Asystole or PEA
What are the 3 most frequent reversible causes of paediatric cardiac arrest? Are most paediatric arrests primary cardiac?
Hypoxia, hypovolaemia & vagal stimulation
No- they are most commonly asphyxial arrests from progressive resp failure or shock
What’s the rate of compressions & ventilations in paediatric cardiac arrest?
100-120/minute & 12-20 breaths/minute
Is atropine recommended for paediatric cardiac arrest? If so, dose?
Not unless it’s due to bradycardia ass’d w increased vagal tone, in which case, 0.02mg/kg
What’s given after the 2nd & 3rd shock in VF/VT arrest in paediatrics? How about non-shockable
adrenaline 10mcg/kg after the 2nd shock (then every 2nd loop), after the 3rd shock amiodarone 5mg/kg given
For nonshockable, adrenaline 10mcg/kg immediately then every 2nd loop
If the IV & IO routes are unsuccessful, how else can adrenaline be given & what dose?
100microg/kg via endotracheal route
If using an AED in paediatric cardiac arrest, what special setting should be selected for children <8yo? What’s the energy for paediatric shock?
“paediatric attenuated adult shock energy”
4J/kg
What are some considerations during post-resus care?
Consider thrombolysis Temperature management (consider 32-36 deg, AVOID hyperthermia, shivering) Avoid hyperglycaemia (treat if >10mmol/L) Aim SpO2 94-98%, avoiding hyperoxaemia Avoid hypercarbia
:) What are the first 4 actions for managing myocardial ischemia intra-op?
- apply supplemental oxygen- goal normal SpO2
- Ensure adequate ventilation, anaesthesia, analgesia
:) If you’ve done the first 4 steps of management for intraop myocardial ischaemia, what are the next actions?
- Optimise myocardial O2 supply & minimise demand
- Confirm ST changes (typically new horizontal or downsloping depressions) w expanded monitor view or 12-lead ecg
- If ST elevation, consult cardiologist & surgeon immediately, have defibrillator readily accessible
- If ST depression, aim to reduce O2 demand while increasing O2 supply by:
- Ensuring maintain supplemental O2 (target normal SpO2 >=95%)
- Control HR (aim 50-60bpm), deepen/analgese or if not improve, consider B blocker- correct arrhythmias- eg. could use lignocaine 1mg/kg IV for tachyarrhythmia
- reduce shivering & fever- warm, paracetamol
- afterload reduction- analgesia, anaesthesia, IV B blocker or consider nitroglycerin (titrate infusion 10-200microg/min; 0.1-3mcg/kg/min)- nitroglycerin dilates coronaries & decreases LV preload (ventilation)- balance against risk of hypoT & tachycardia (balance with alpha blocker)
If the pt is hypERtensive:
- cease stimulation (communicate w surgeon)
- introduce a B-blocker
- consider GTN infusion
If the pt is hypOtensive (targets MAP 75, DBP 65)
- correct any volume loss- check Hb, give blood if pt anaemic (target 90g/L in pts with ACS or signs of myocardial or other organ ischaemia, esp if ongoing bleeding) or crystalloid if need volume
- treat any inappropriate vasodilation by adjusting anaes dose or carefully titrating vasoconstrictor to avoid adverse increased afterload
- vasoplegia (eg. if septic or prior ACE-inhibitors) Rx with vasopressin (direct peripheral vasoconstrictor) or norepinephrine.
Other considerations are:
- invasive monitoring
- echo to assess RWMAs, contractility & filling pressures
- control filling pressure (CPP=ADP-LVEDP, avoid elevated LVEDP since the distal coronary pressures can be low++ w severe coronary artery obstruction)
- support contractility- consider an inodilator or inotrope
- once volume & BP corrected (maintain MAP >75mmHg to assist O2 supply), carefully titrate GTN infusion to dilate coronaries & reduce LVEDP
- Consider anticoagulation, placement of IABP, PCI
- manage of any electrolyte abnormalities
- Aim SBP 100-120 & MAP >75
If myocardial ischemia persists, consider NSTE ACS & seek urgent cardio R/V
What’s the dose of lignocaine for managing tachyarrhythmia?
1mg/kg
How is GTN useful for myocardial ischemia?
assists CPP by both: dilating coronaries and reducing LVEDP (reduces filling pressure as dilates venous capacitance vessels)
What are the drug doses of sympathomimetic infusions for a 70kg pt?
Dobutamine: 250mg in 50mL 0.9% saline
Adrenaline: 3mg in 50mL 0.9% saline
NAdr: 4mg in 50mL 0.9% saline
Commence @ 5mL/hr & titrate to response
What are the doses of vasopressors/B-blockers/vasodilators to use in emergency?
Metoprolol: 2.5mg boluses
Esmolol: 0.5mg/kg bolus, 50microg/kg/min infusion (titrate)
Phenylephrine: 25-50microg bolus
Metaraminol: 0.5-1mg bolus
GTN: 50microg in 50mL 0.9% saline, commence @ 3-5mL/hr & titrate to response
What are the steps for intra-op cardiac arrest (shockable)??
Check pt/monitors & confirm diagnosis
Commence CPR 100-120/min & apply 100% O2
Call for help, communicate the emergency situation, delegate (as many hands as needed- team leader, CPR (& alternations every rhythm check), airway/ventilation, defibrillator, scribe/timekeeper, other jobs (eg. bloods, IVT)
stop agent & secure airway (by most experienced operator, confirm w capnography) while applying pads
deliver shock- back to CPR w minimal interruption (always <5secs)
4H’s & 4T’s
every 2 mins- rhythm check+/- shock
Adr 1mg after 2nd & immediately after every alternate shock
Amiodarone 300mg IV after 3rd shock, 150mg IV after 5th shock
Consider: activate Cath lab or ECMO
What’s the aim for diastolic BP & EtCO2 during compressions for both paeds & adults? What to do if spike in EtCO2 during compressions? What if EtCO2 drops to <10mmHg?
> 20mmHg, >20mmHg. Continue compressions until end of cycle, quick rhythm check during next changeover
Adjust technique & change compressor each cycle if EtCO2 <10mmHg
Which IO routes could use?
humeral or tibial
What are the goals of post-resus care?
TTM (32-36deg)- AVOID hypothermia SpO2 94-98%- avoid hyperoxaemia avoid hyperglycaemia (treat if BGL >10mmol/L) avoid hypercarbia consider thrombolysis
What drug can be used in adult cardiac arrest if amiodarone n/a? how about paeds?
lignocaine 1mg/kg
This dose, followed by 20mcg/kg/min infusion, can be used for paeds
What’s the sequence of Mx for non-shockable cardiac arrest?
-Check monitors/confirm diagnosis- checking all (ECG, SpO2, ABP waveform, capnography) quickly distinguishes btwn artefact/calibration from asystole/PEA
-Stop vagal stimulation & commence 100% O2
-Call for help, declare emergency, delegate (TL, compressions (alternate every rhythm check), airway/ventilation, scribe/timekeeper, drugs, bloods/runner- as many hands as need)
Commence CPR 100-120/min & give 1mg Adr immediately
Stop agent, consider intubation (by most experienced operator, confirm w capnography) @ next rhythm check
4H’s, 4T’s
Consider TTE during brief interruption of CPR (<5secs)
1mg Adr IV every 2nd cycle
If rhythm changes to VF/VT, shock & go to shockable algorithm
consider pacing for asystole w p waves
consider Cath lab or ECMO
What’s the optimal CPR compression depth for paeds?
1/3 chest depth, allow complete recoil
What’s EtCO2 useful for during arrest?
confirmation of airway placement, checking CPR effectiveness, monitoring CO
What are causes of intraop myocardial ischemia?
ruptured atherosclerotic plaque or inadequate coronary perfusion pressure
