Readings

• Contribution of ventricular filling due to the contraction of the atria is referred to as the atrial kick
• Afterload is the the pressure against which the heart contracts to eject blood
• When afterload is higher, either cardiac output drops or the heart has to work harder to maintain the same cardiac output
• The heart can vary the degree of contraction without changing the stretch of the muscle; this property is called contractility or inotropy
• Chronotropy is the rate at which the heart beats
• SA node normally receives blood from the right coronary artery
• Electrical impulses in the SA node propagate through internodal pathways including the bachmann bundle.

  
• 70% of the blood in the atria fills ventricles via gravity and 30% comes by the atrial kick
• Dromotropic effects refers to the velocity of conduction of the heart
• Shoulder's should be over PT's sternum during compressions and elbows should be straight
• Shock energy for defib is either biphasic(120, 150, 200J) or monophasic(360J)
• Rhythm should be analyzed with a simultaneous pulse check
• Other factors besides V-tach and V-fib can produce disorganized waveform. These are factors such as: loose ECG leads and muscle tremors
• Immediately get on compressions after a shock as even if there's an organized rhythm on the monitor, ROSC is often delayed and doing compressions may help maintain pulse or prevent return of VF/VT
• Causes of PEA: hypoxia, hypovolemia, acidosis, hyperkalemia/hypokalemia, hypothermia, cardiac tamponade, tension pneumothorax, pulmonary embolus and toxins
• The purpose of Defibrillation is to depolarize all of the heart's muscle cells. Ideally when the cells repolarize, they respond to the SA node and begin organized depolarization
• Defibrillation is not useful in asystole because there is no evidence all the myocardial cells are spontaneously depolarizing.
• Remove nitroglycerin patches on the PTs chest and wipe skin before placing pads
• Electrical Cardioversion is the use of the defib to terminate tachydysrhythmias in a PT with a pulse. Done in the same manner as defibs but synchronize setting on the defib is selected first.
• Cardiac arrest standards states that suction equipment should be readily available in preparation of emesis
• According to cardiac arrest standards, if there is ROSC, administer O2 to maintain spo2 at 94-98%
• According to cardiac arrest standards, when doing CPR on a pregnant PT with uterine height at or above umbilical, have second paramedic manually perform left uterine displacement
• After 1 analysis minimum and with egress plan organized, consider early transport for these medical VSAs scenarios: pregnancy presumed to be >20 weeks, hypothermia, airway obstruction, non-opioid drug OD, other known reversible cause of cardiac arrest
• According to ALS, for PTs in refractory VF or pulseless VT, transport should begin after 3rd consecutive shock.
• In order for medical TOR to be valid: PT must be over 16 years of age, arrest must not have been witnessed by Paramedic, no ROSC after 20 minutes of resus and no defibrillation delivered
• Contraindications for CPR is obviously dead per BLS or meeting the conditions of DNR in BLS
• Contraindications for obtaining TOR: known reversible cause of the arrest is unable to be addressed, pregnancy is greater than 20 weeks gestation, suspected hypothermia, airway obstruction and non-opioid drug OD
• Patch following the 4th analysis to consider TOR
• Patch following the 4th analysis to consider TOR for extenuating circumstance such as: bad egress, prolonged transport or significant clinical limitations where paramedic considers ongoing CPR to be futile. Otherwise full 20 minutes is done
• Base hospital may not authorize TOR even if PT meets the criteria. Factors affecting this could be: location of PT, age, EtCO2, bystander witness/CPR, transport time and unusual causes of arrest such as electrocution, hanging and toxicology
• The base hospital may authorize a TOR even when the PT does not meet the criteria
• Conditions for a trauma TOR include: no palpable pulse, no shocks given, they're in asystole, no signs of life at any time since extrication or signs of life since extrication with closest ED being >30 minutes away or they're in PEA with closest ed being >30 minutes
• For trauma VSA, patch to base hospital for Trauma TOR if applicable. If it fails or doesn't apply, transport to closest facility after 1st analysis
• Causes of Trauma VSA AIRWAY: FBAO, tongue, swelling, tracheal damage, blood in airway and misplaced advanced airway
• Causes of Trauma VSA breathing: tension/open pneumothorax, flail chest, high SCI, CO poisoning, smoke inhalation, aspiration, non-fatal drowning, CNS depression drugs/alcohol and apnea secondary to electric shock or lightening strike
• Causes of trauma VSA circulatory: hemorrhagic shock, tension pneumothorax, cardiac tamponade, myocardial contusion, acute myocardial infarction and Cardiac arrest secondary to electric shock
• PTs with cardiac tamponades are often in the PEA rhythm
• Commotio cordis: refers to when there's a blow to the anterior chest during cardiac repolarization that causes v-fib rhythm
• The field correctable causes of trauma VSAs are : hypoxia, hypovolemia, hypothermia, hyperkalemia, acidosis and tension pneumothorax and cardiac tamponade