ALS Flashcards
Advanced life support
How long is the CPR cycle, from shock to reassessment of rhythm?
2 minutes
What drugs are used in CPR with shockable rhythm? When are these used?
Adreneline 1mg after the 2nd shock and then every second loop; Amiodarone 300mg after 3 shocks
What drugs are used in CPR with non-shockable rhythm? When are these used?
Adreneline 1mg immediately (as soon as access is obtained), then after every 2nd loop
Name the 4 H’s and 2 T’s to consider and correct during ALS
Hypoxia (oxygen, airway); Hypovolaemia (IVT); Hyper/hypokalaemia or metabolic disorders; hypo/hyperthermia; Tension pneumothorax; tampon add; toxins; thrombosis (pulmonary or coronary)
Name the 5 things you should do in post-resuscitation care following ALS where patient has had ROSC
Reevaluate ABCDE; 12 lead ECG; treat precipitating causes; targeted temperature management; aim for stats 94-98% and normocapnia and normoglycaemia
Name the 4 elements of the Chain of Survival in ALS
- Early recognition and call for help (to prevent cardiac arrest) 2. Early CPR (to buy time) 3. Early defibrillation and ALS (to restart the heart); 4. Post-resuscitation care (to restore quality of life)
Defibrillation should be attempted within ___ minutes of identifying cardio respiratory arrest
3
What proportion of in-hospital cardiac arrests survive and go home?
20%
List the favourable prognostic indicators of survival of in-hospital cardiac arrest
Witnessed, VF, primary MI as the cause, immediate and successful defibrillation
List the 5 links of the Chain of Prevention
Education, monitoring, recognition, call for help and response
List some of the physiological consequences of partial airway obstruction
Cerebral oedema, pulmonay oedema, exhaustion, secondary apnoea, hypoxic brain injury, cardiac arrest. Partial airway obstruction also often precedes complete obstruction
List ath least 6 causes of airway obstruction
CNS depression (loss of airway reflexes and patency), blood, vomitus, foreign body, direct trauma to the face or thorat, epiglottitis, pharyngeal swelling, laryngospasm, bronchospasm, bronchial secretions, blocked tracheostomy or laryngectomy
List some causes of CNS depression that can cause airway obstruction
Head injury, intracerebral disease, hypercapia, metabolic disorders (hypoglycaemia), depressant drugs (alcohol, opioids, GA)
When does laryngospasm occur?
With upper airway stimulation in a semi-conscious patient whose airway reflexes remain intact
What is ‘see-saw’ breathing and what is this a sign of?
Sign of airway obstruction where the accessory muscles of breathing are engaged and the chest is drawn in on inspiratory effort and the abdomen is thrust outwards
What is the treatment for airway obstruction in resuscitation?
Treat any problem that places the airway at risk (suction blood/gastric contents) turn patient on side and given oxygen as soon as possible to maintain sats 94-98%
Describe the the innervation of the main inspiratory muscles, and how a spinal cord lesion might lead to poor respiratory effort or arrest
Intercostal muscles, innervated at the level of their respective ribs, so spinal cord lesions above a particular level may paralyse. The diaphragm is via the 3rd, 4th and 5th segment of the spinal cord. Spontaneous breathing cannot occur with severe spinal cord damage above this level
Describe the effect of a tension pneumothorax on BP
Reduces venous return to the heart and reduces BP
Describe a mnemonic that can be used to assess breathing in the deteriorating patient
RATES - respiratory rate, auscultation, trachea (protrusion vs tug), effort of breathing, saturation
Describe how oxygen should be given to all acutely ill patients who are hypoxic
15L/min via a high concentration reservoir mask (he high volume is to ensure the reservoir bag doesn’t collapse during inspiration). AIm for sats 94-98%
In acutely ill patients, circulation problems are most commonly caused by ______
Hypovolaemia
What is the most common arrest arrythmia associated with ACS?
VF
List at least 5 causes of VF
ACS, hypertensive heart disease, valvular disease, drugs (antiarrthymics, TCAs, digoxin), inherited cardiac diseases like long-QT syndrome, acidosis, abnormal electrolytes, hypothermia and electrocution
List the 4 categories of ACS
STEMI, NSTEACS, NSTEMI, UA
Describe the initial treatment of ACS
Aspirin 300mg crushed or chewed, GTN spray or tablet unless hypotensive, oxygen if hypoxic (sats <94 or hypoxic), pain relief with IV fentanyl or morphine (MONA)
What element of ACS management is different when managing an Indigeous, Maori or Pacific Islander patient?
If giving fibrinolysis, avoid streptokinase due to the high prevalence of anti-streptokinase antibodies in these groups (other drugs would be more effective)
What is the most common cause of sudden cardiac death?
CAD
Why is a history of syncope important in patients with known cardiac disease?
Because syncope is an independent risk factor for increased risk of death
List at least 4 features that indicate a high probability of arrhythmic syncope
Syncope whilst lying down, during or after exercise (though after exercise is commonly vasovagal), with no or brief warning signs, in those with a family history of sudden death or inherited cardiac condition, repeated episodes of unexplained syncope
Name at last 5 signs and symptoms of cardiac disease
Chest pain, SOB, syncope, tachycardia, bradycardia, tachypnoea, hypotention, poor peripheral perfusion, altered mental state, oliguria
Give some examples of asymptomatic or ‘silent’ cardiac disease which can lead to sudden cardiac death
Hypertensive heart disease, aortic valve disease, cardiomyopathy, myocarditis and coronary disease
List at least 3 general signs of respiratory distress
Sweating, central cyanosis, use of accessory muscles, abdominal breathing
What do rattling airway noises in a deteriorating patient suggest?
Airway secretions, usually because the patient cannot cough or take a deep breath
Surgical emphysema in the chest suggests ____ until proven otherwise
Pneumothorax
How should oxygen be administered to patients at risk of T2 respiratory failure if they are hypoxic?
Aim for sats 88-92% with Venuri 28% mask or Venturi 24% mask
What should be done in an emergency situation if a patient has inadequate rate or depth of ventilation?
Use a 2 person bag/mask technique to achieve adequate ventilation whilst calling for help. In a conscious cooperative patient, consider NIV.
In all medial and surgical emergencies, consider ____ to be the likliest cause of shock unless proven otherwise.
Hypovolaemia
In a resusciation setting, what should be given to any patient with cool peripheries and tachycardia? Why?
IV fluids - because hypovolaemia is the most common cause of shock
Explain why BP can be normal in the shocked patient
Because compensatory mechanisms will increase peripheral vascular resistance in answer to reduced cardiac output
In a resusciation setting, a low diastolic BP indicates what?
Arterial vasodilatation (anaphylaxis or sepsis)
In a resusciation setting, a narrowed pulse pressure indicates what?
Arterial vasoconstriction (cardiogenic shock or Hypovolaemia)
Describe what fluid therapy you would give in resuscitation of the deteriorating patient
Rapid bolus 500mL crystalloid (Hartmann’s or NaCl) over less than 15 minutes. Uses smaller volumes (250mL) in patients with heart failure or trauma
What are the 3 D’s that are assessed in the ABCDE algorithm?
Disability - includes drugs, documentation and diabetes
Give an example of how you might treat BGL < 4 in a patient who is unconscious
Give 50mL of 10% glucose IV. Give further doses until the patient fully regains consciousness, or until 250mL of 10% glucose has been given
What is the minimal monitoring that should be attached to the unconscious/deteriorating patient?
ECG, BP and sats
Describe the management of the unconscious patient’s airway if there is a risk of C spine injury
Use jaethrust or chin lift in combination with manual in-line stabilisation of the head anc neck by an assitant. In life-threatening airway onstruction despite the above, add head tilt a small amount at a time until the airway is open
What is agonal breathing and what it this a sign of?
Occasional, irregular gasps - common in the early stages of cardiac arrest. Sometimes present during chest compressions as cerebral perfusion improves, but this is not considered to be ROSC
What is the correct hand position for CPR?
The middle of the lower half of the sternum
Survival rates in CPR are best when the rate is between ___ and ____ per minute
100-120
What is ‘the duty cycle’ of CPR?
Refers to chest compressions and the compression/recoil being of the same duration
Regardless of the method in which ventilating, use an inspiratory time of ___ during resuscitation
1 second
Ventilate the lungs at ___ breaths per minute during resuscitation where intubation has been completed
10 breaths
What equates to ‘1 loop’ on the BLS algorithm?
1 loop is each 2 minute cycle between rhythm checks (the number of 30:2 is less important - use a timer to do a rhythm check every 2 minutes - this is 1 cycle)
What does it indicate when a collapsed patient is found to have a pulse but is not breathing?
Respiratory arrest (diagnosis can only be made if the patient has other signs of life i.e., warm and well perfused, normal CRT)
What are the first steps in resuscitation of a patient who is found to have a pulse but is not breathing?
Ventilate the lungs and check for a pulse every 10 seconds - if there is any doubt about the presence of a pulse, start CPR (all patients in respiratory arrest will develop cardiac arrest)
In what rare circumstance can you deliver ‘stacked shocks’ to a patient in cardiac arrest
If witnessed, if was well oxygenated and perfused immediately prior to the attack (usually in a high dependency unit in hospital), if a manual defibrillator is available and a shock is able to be delivered within 20 seconds, if the initial rhythm is AF/pVT - give 3 successive shocks and assess for ROSC after each shock. If unsuccessful after the third, start CRP. This counts as the first defib attempt in the algorithm
What are the 2 most important interventions that improve survival after cardiac arrest?
Early and uninterrupted chest compressions, and earlu defibrillation for VF/pVT
Describe the appropriate pad placement in ALS
One below the right clavicle, the other in the V6 position in the mid-axillary line
What is the appropriate charge to set on a manual defibrillator in ALS?
200J biphasic for the first shock, which may be increased to 360J for subsequent shocks
Assume that you are doing ALS and, at rhythm check, the pateint displays organised electrical activity compatible with a cardiac output. What is the next step?
Dump the charge and check for ROSC. If present, start post-resus care. If absent, continue CPR and switch to the non-shockable algorithm
Assume that you are doing ALS and, at rhythm check, the pateint displays asystole. What is the next step?
Dumpt he charge, continue CPR and switch to the non-shockable algorithm
The time until ROSC in a successfully defibrillated patient can be as long as _____
2 minutes
Give the 4 reasons why chest compressions should be resumed immediately after delivering a shock in ALS
- Even in successful shocks, it can take up to 2 minutes for ROSC to be detectable 2. Delay in palpating a pulse will further compromise myocardium 3. If a perfuming rhythm has been restored, compressions will not increase the chance of VT recurring 4. In the presence of post-shock asystole, chest compressions may ruefully induce VF
When is amiodarone 300mg given in cardiac arrest?
After 3 shock attempts (any three in an arrest and do not need to be sequential) - can also consider a further 150mg if VT/VF persists afterwards total of 5 shocks
What drug may be used in ALS if amiodarone is not available?
Lignocaine 1mg/kg (but not if amiodarone already given)
What action should be taken in ALS if rhythm cannot be easily distinguished between asystole vs fine VF?
Do not attempt defibrillation, continue compressions and ventilation - as this may improve the amplitude and frequency of VF and therefore the chance of subsequent successful defibrillation
In what situation can precordial thump be considered in cardiac arrest
Rarely - i.e., in a monitored patient in VF/pVT arrest prior to arrival of the defibrillator
Describe the technique for precordial thump
Using the ulnar edge of a tightly clenched fist, deliver sharp impact to the lower haf of the sternum from a height of about 20cm, then retract the fist immediately to create an impulse-like stimulus
How is PEA defined?
Cardiac arrest in the presence of electrical activity (other than VT) that would normally be associated with a palpable pulse (may have some mechanical myocardial contractions but they are too weak to produce a detectable pulse or BP)
Survival following cardiac arrest with asystole or PEA is unlikely unless ?
A reversible cause can be found and treated quickly and effectively
If the diagnosis of asystole is made during cardiac arrest, what other ECG finding should be assessed?
Whether there are p waves - because in these cases, ventricular standstill may be treated with pacing
Physiologically, why is minimisation to pauses in chest compression during CPR so important?
Because even short pauses drastically reduce coronary artery perfusion
What is end-tidal CO2?
The partial pressure of CO2 at the end of an exhaled breath (reflects cardiac output and lung blood flow)
Explain why end tidal CO2 monitoring during CPR is helpful
During CPR, the end ETCO2 is expected to be low, reflecting the low cardiac output state generated by chest compressions. An increase in the monitored CO2 values to normal or near normal may indicate ROSC - waveform capo graphs enables continuous and real time monitoring
List the 5 roles of waveform capnography during CPR
Ensuring correct ETT placement, monitoring ventilation rate and avoiding hyperventilation, monitoring quality of chest compressions (high quality will increase the value), identifying ROSC, prognostication during CPR
If ROSC is suspected during CPR, which drug should be withheld?
Adrenaline
How should drugs which are given peripherally be administered during CPR?
Followed by a 20mL flush (at least) and elevation of the extremity for 10-20 seconds to facilitate drug delivery to the central circulation
What are the 3 sites for IO access in CPR when peripheral access cannot be obtained?
Proximal tibia, distal tibia and proximal humerus
Many hypovolaemic cardiac arrests present with what type of arrythmia?
PEA
Severe hyperkalaemia is K+ above which value?
6.5
What drug is indicated in CPR if the patient is found to be hyperkalaemic?
Calcium
How does calcium work in the treatment of hyperkalaemia?
Directly antagonises myocardial effects of hyperkalaemia by restoring cariomyocyte resting membrane potential, thereby stabilising the cell membrane (i.e., does not decrease serum K+)
If severe acidosis or renal failure is present in a resuscitated patient, which agents should be considered for administration?
Sodium bicarbonate 50mg mmol IV
What is the dose of calcium used in the treatment of hyperkalaemia?
calcium chloride 10% in 10mL
In addition to calcium, which other agents can be used in the management of hyperkalaemia during cardiac arrest?
Shifting agents such as 25g of glucose + units of short acting insulin
Give 2 reasons why calcium carbonate preferred to calcium gluconate in the treatment of hyperkalaemia during cardiac arrest
Firstly, it contains a higher quantity of elemental calciu,, and secondly calcium guconate needs to be hepatically metabolised before the calcium is bioavailable
List at least 3 causes of acute hypocalcaemia which may be seen in cardiac arrest
Shock, sepsis, pancreatitis and drug toxicities
Give an example of why calcium replacement may be beneficial in cardiac arrest
Increased extracellular calcium concentration creates a high calcium gradient which may cause calcium influx and lead to improvement in conduction disturbances and contractility
Hypokalaemia is defines as a serum K+ less than _____?
3.5 (severe < 2.5)
List at least 3 causes of hypokalaemia in the context of cardiac arrest
Usually related to loss or intake including from drugs, gastrointestinal and renal/dialysis or poor intake
Describe how to treat hypokalaemia during cardiac arrest
Administer potassium 5mmol IV as a bolus with consideration of magnesium sulfate 2g IV
Why should you consider giving magnesium sulfate 2g IV with potassium 5mmol for treatment of hypokalaemia in cardiac arrest?
Repletion of magnesium stores will facilitate a more rapid correction of hypokalaemia
How is hypothermia classified?
Body core temperature before 35, and arbitrarily classifed as mild (32-35), moderate (28-32) or severe ( <28)
What is the Swiss staging system?
A way of classifying hypothermia using clinical signs, using 5 stages where 1 relates to mild hypothermia and 5 = death
Describe Stage I of the Swiss staging system
Mild hypothermia (conscious, shivering, core tem 32-35)
Describe Stage II of the Swiss staging system
Moderate hypothermia (impaired consciousness without shivering, core temp 28-32)
Describe Stage III of the Swiss staging system
Severe hypothermia (unconscious, vital signs present, core temp 24-28)
Describe Stage IV of the Swiss staging system
Cardiac arrest or low flow state (no or minimal vital signs, core temp <24)
Describe Stage V of the Swiss staging system
Death due to irreversible hypothermia (core temp 13.7)
Explain how hypothermia affects cardiac function
As core temperature decreases, sinus bradycardia (which is physiological in severe hypothermia) tends to give way to AF, followed by VF and finally asystole
Explain how to manage the hypothermic patient in cardiac arrest with VF, who has not responded to 3 defibrillation attempts
Delay further attempts until core temp 28-30 degrees. CRP and rewarming may need to continue for several hours to facilitate successful defibrillation
Explain why it is reasonable to withhold drugs in CPR for the hypothermic patient, until core temp 28-30
The hypothermic heart may be unresponsive to drugs, attempted pacing and defibrillation. Drug metabolism is slowed, which may lead to toxic plasma concentrations of any drug given
True or false? In the hypothermic patient in cardiac arrest, the interval between any drug doses given should be double that given in a normothermic patient
True - due to delayed metabolism and potential for accumulation
What does ‘after drop’ refer to in regards to the hypothermic patient requiring CPR?
The continued fall in the core temperature after removal from the cold stress due to heat redistribution within the body
Explain why large volumes of IV fluids are needed in the post-resuscitation care of the hypothermic cardiac arrest patient
Warm fluids will cause vasodilatation and expansion of the intravascular space
What temperature is considered diagnostic for hyperthermia?
> 40.6
What is heat exhaustion? What are the symptoms?
A condition of fatigue caused by prolonged exposure to high temperatures, particularly when combined with high humidity and strenuous activity. Symptoms include headache, N+V, malaise. Usually recover rapidly with assistance. Do not usually present with hyperthermia, the body temp is <40
What is heat stroke?
Systemic inflammatory response with a core temp > 40, accompanies by altered mental status or collapse and a varying level of organ dysfunction. Sweating ceases, hot dry skin is present
At what body temperature is sweating maximal?
39 degrees (if fluid not replaced, the sweating will cease and body temperature will rise more quickly)
Explain how exercise in hot environments can result in heat stroke
During exercise, metabolic energy is converted to thermal energy. A large proportion of this energy is liberated as heat. Humans rely on heat loss through evaporation (sweating, breathing). As the environmental temperature rises, the gradient for heat exchange is altered and body temperature rises making it more difficult again to liberate the thermal energy. Sweating will increase, but if fluid not replaced, sweating will cease and the core temperature will rise more quickly.
In which cause of hyperthermic cardiac arrest are pharmacotherapies useful?
Only if caused by malignant hyperthermia (from anaesthetics). In these cases, the offending agent is ceased and dantrolene is given (some evidence that other drugs that cause malignant hyperthermia like MDMA and amphetamines may be treated by dantrolene)
In what arrest setting should one consider immediate administration of a fibrinolytic drug?
If massive PE is suspected as the cause (i.e., one of the 4 T’s)
What is the recommended duration of CPR for a patient who has arrested secondary to a suspected PE and who has been give fibrinolysis?
CPR for at least 30 minutes and up to 90 minutes before terminating
Name the 4 T’s of cardiac arrest
Thrombosis, tension pneumothorax, tamponade and toxins
What is tension pneumothorax? Explain how this condition can lead to cardiac arrest
Progressive build up of air in the pleural space (usually due to a laceration whereby air is allowed into the pleural space but not to return). Progressive build up of pressure pushes the mediastinum toward the opposite hemithorax, and also obstructs venous return to the heart one intra-thoracic pressure exceeds vascular/central venous pressure, thereby leading to circulatory instability and cardiac arrest
Tension pneumothorax in cardiac arrest is a clinical diagnosis. Give some examples of stations where this pathology may be suggested
Thoracic trauma (penetrating or blunt), iatrogenic (thoracic surgery or procedures including central lines, pacemakers, pleural biopsy etc.), asthma, COPD, pulmonary barotrauma
Give some examples of how a patient with a tension pneumothorax might present in the peri-arrest phase
Chest pain, respiratory distress, increasing then decreasing (per-terminal) RR, air hunger, tachycardia, low/falling sats, hypotension and altered consciousness
List at least 3 clinical signs during CPR that may be present in a patient with tension pneumothorax as the cause
Difficulty ventilating due to back pressure, abnormal rise/fall of chest on affected side, decreased breath sounds on affected side, hyper-expanded chest with increased percussion note, tracheal deviation away from the affected side
What is the treatment for tension pneumothorax?
Rapid decompression by thoracostomy or needle thoacocentesis (14G) - when stable, all will have imaging and an established chest drain should be sited, regardless of the technique used
Give at least 5 examples of why needle decompression may fail in the treatment of tension pneumothorax
Obstruction (blood, tissue, kinking cannula), missing a localised tension pneumothorax (cannula too short), inability to drain a large air leak, moving/dislodging
What is the main advantage of needle decompression in the treatment of tension pneumothorax?
Fast (though may recur if not monitored)
What is cardiac tamponade?
Slow or rapid compression of the heart due to the pericardial accumulation of fluid, pus, bloods, clots or gas. Can be the result of effusion, trauma or rupture of the heart, resulting in decreased ventricular filling and subsequent haemodynamic compromise
Explain why cardiac tamponade is difficult to diagnose as a cause of cardiac arrest
Because the typical signs (Beck’s Triad: distended neck veins and hypotension, muffled heart sounds) cannot be assessed during resuscitation/arrest - instead, focussed US should be used
Give at least 5 examples of situations in which cardiac tamponade may be the cause of cardiac arrest
Thoracic trauma, recent thoracic/cardiac surgery, insertion of central access, recent angio or PCI, recent MI, thoracic neoplasm or mediastinal RT, renal failure (uraemia), pericarditis, infectious disease such as TB
List at least 3 clinical signs during CPR that may be present in a patient with cardiac tamponade as the cause
Tachypnoea, dyspnoea, pulsus paradoxus, low voltage QRS or electrical alternans on ECG, Kussmaul’s sign
What is Beck’s triad?
Triad of signs that are diagnostic for cardiac tamponade - distended jugular veins, muffled heart sounds and hypotension
List at least 4 complications of pericardiocentesis
Cardiac dysrhythmia, cardiac puncture, pneumothorax, coronary vessel injury, diaphragmatic injury and death
What is the mainstay of treatment in tricyclic toxicity causing cardiac conduction abnormalties?
Sodium bicarbonate (consider giving during arrest if this is the suspected cause, or in the peri-arrest period if there are still abnormalities on ECGC)
Describe the ways in which amphetamines can cause cardiac arrest
Can cause AMI, necrosis, arrythmias, cardiomyopathy and acute heart failure. They precipitate vascular spasm and therefore cause ischaemic infarction - the myocardial ischaemia causes massive effluent of potassium which can cause arrythmias. The drugs themselves can also induce other reversible causes of cardiac arrest
In what ways can snakes be identified after snake bite?
Residual venom on clothing or skin, or via urine or blood
Describe the process for checking for signs of life during ALS
If signs of life (regular respiratory effort, movement) or readings from monitors are compatible with ROSC (sudden increase in end-tidal CO2 or arterial BP waveform), stop CPR briefly and check the rhythm. If an organised rhythm is present, check for a pulse. If palpable, continue post-resuscitation care. If nil, continue CPR
If CPR does not achieve ROSC and a decision is made to discontinue, for how long should the patient be observed before confirming death?
5 minutes (Andy return of cardiac or respiratory effort during this time should prompt a further 5 minutes observation.
The absence of mechanical cardiac function is normally confirmed using a combination of which signs?
Absence of a central pulse on palpation, absence of heart sounds on auscultation. These can be supplemented by one or more of: asystole on continuous ECG, absence of pulsative flow on arterial monitoring, absence of contractile activity on US
Presume efforts for CPR have been ceased and then patient has been observed for 5 minutes. Which signs must then be checked to confirm death?
Absence of pupillary reflexes, corneal reflexes, motor response to supra-orbital pressure
In an unconscious patient, what is the most common site of airway obstruction?
The pharynx, more often at the epiglottis and soft palate rather than the tongue
List some broad causes of upper airway obstruction in the unconscious patient
Vomit, blood, gastric contents, trauma to the airway, foreign bodies
List some broad causes of laryngeal obstruction
Oedema from burns, inflammation or anaphylaxis, upper airway stimulation (inhaled foreign body) causing laryngospasm
List some broad causes of lower airway obstruction, below the level of the larynx
Excessive bronchial secretions, mucosal oedema, bronchospasm, pulmonary oedema, aspiration of gastric contents
True or false? In the unconscious patient, lower airway obstruction is more common than upper airway obstruction
False.
List at least 2 examples of airway obstruction caused by extrinsic compression
Trauma, haematoma, tumour
Compare the causes of inspiratory stridor vs expiratory wheeze when assessing for airway obstruction
Inspiratory atidor is caused by obstruction at the larynx or above. Expiratory wheeze suggests obstruction of the lower airways, which tend to collapse and obstruct during expiration