trauma to the chest, distended neck veins, tracheal deviation (away from side of injury), and decreased breath sounds on side of injury. cardiac tamponade: a build up of fluid or blood in the space surrounding the heart (pericardium) causing compression of the heart. common signs include muffled heart sounds and pulsus paradoxus. pulmonary embolism: obstruction of a pulmonary artery or a branch of the pulmonary arteries most commonly by a clot causing blocked flow of blood out of or back into the heart. children with predispositions to forming clots such as those with sickle cell disease, cancer, coagulation disorders, and central venous catheters are more likely to have pulmonary emboli. common signs include worsening heart and lung function as evidenced by chest pain, tachycardia, shortness of breath, heart failure, and more. management management of shock should be based on the type of shock. when the type of shock hasn't been identified yet, the provider should start with some initial treatments and labs. all children with suspected shock should receive supplemental oxygen, ventilation if in respiratory distress (via nasal canula, high flow nasal canula, noninvasive ventilation, or mechanical ventilation), and treatment for life-threatening conditions. providers should establish vascular access (intravenous access and if that isn't possible, intraosseous access (io) or central venous line). providers should also obtain initial lab studies including a rapid blood glucose, basic metabolic panel (bmp) (measures serum electrolytes, blood urea nitrogen, and creatinine), lactic acid level, complete blood count (cbc), and urine dipstick. normal saline fluids the provider should start crystalloid fluids (normal saline or lactated ringers). for compensated shock give 10-20 ml/kg over 5-20 min and for hypotensive shock, give 20 ml/lg over 5-10 min. however, if there are signs that the patient has too much fluid (fluid overload) such as worsening respiratory distress, jugular venous distention, crackles, hepatomegaly, then fluids should not be given. with continued signs of shock and no signs of fluid overload, kids can continue to receive 10-20 ml/kg of fluids with a max of 60 ml/kg in the first hour. however, if cardiogenic shock is suspected, kids should receive less fluids over a longer time (e.g., 5-10 ml/kg over 15-30 min). hypovolemic shock hypovolemic shock is mainly treated with fluid replacement, as described in the fluids section above. if the hypovolemic shock is caused by a hemorrhage, then the provider should obtain blood type, blood cross match, and coagulation studies (pt, inr, ptt). in hemorrhagic shock, patients should receive blood or blood products if they aren't improving with fluids. distributive shock distributive shock is mainly treated with fluid replacement, as described in the fluids section above, and vasopressors. for those with suspected septic shock, providers should obtain blood culture, urinalysis, urine culture, c-reactive protein (crp) (marker of inflammation), procalcitonin (marker of inflammation), fibrinogen, d-dimer, bilirubin labs, and more. those in anaphylactic shock should be treated with intramuscular epinephrine. cardiogenic shock cardiogenic shock typically worsens with fluids. providers should obtain an ecg and echocardiogram for patients suspected to have cardiogenic shock. treatment can include vasopressors, inotropes, and treatment of any arrhythmias. obstructive shock obstructive shock is treated by treating the underlying cause of the shock. tension pneumothorax is treated with a chest tube and needle thoracostomy which allows the air to get out of the pleural space. cardiac tamponade is treated with pericardiocentesis which removes the fluid from the pericardium and decompresses the heart. pulmonary embolism is treated with anticoagulants (prevent body from making more clots) and if bad enough, thrombectomy (surgical removal of clots). ductal dependent congenital heart defects are treated with prostaglandin e1/ alprostadil which keeps the ductus arteriosus open. cardiac arrest cardiac arrest occurs when the heart stops working and blood stops moving throughout the body. in infants and children, cardiac arrest is typically caused by (1) hypoxic/asphyxial arrest and less commonly by (2) sudden cardiac arrest due to heart problems or arrhythmias. in adults, cardiac arrest is usually caused by heart problems such as acute coronary syndrome. hypoxic/asphyxial cardiac arrest is a result of progressive respiratory failure and/or shock. for this reason, it is important to treat respiratory failure and shock early so that they don't progress to cardiac arrest. sudden cardiac arrest is typically caused by arrhythmias such ventricular fibrillation (vf) and pulseless ventricular tachycardia (pvt). these arrhythmias are more common in kids with hypertrophic cardiomyopathy, cardiac channelopathies (e.g., long qt syndrome), myocarditis, drugs (e.g., cocaine, digoxin), commotio cordis, and anomalous coronary artery. there are many causes of reversible cardiac arrest and the mnemonic "h's and t's" is used to remember these causes. "h's and t's" - reversible causes of cardiac arrest h's t's hypoxia trauma hypovolemia toxins hydrogen ions (acidosis) tension pneumothorax hypoglycemia thrombosis (clot in lungs and heart) hypothermia tamponade (cardiac) hypo/hyperkalemia recognition ventricular fibrillation signs of cardiac arrest include no pulse (within 10 seconds), no breathing or only gasping, and unresponsiveness. as mentioned above, cardiac arrest in kids is mainly a result of respiratory failure and shock, so providers need to treat those conditions quickly and be on the look out for signs of cardiac arrest. because cardiac arrest can also be caused by arrhythmias, providers should get ecgs of these patients. the 4 main cardiac arrest rhythms are ventricular fibrillation (vf), pulseless ventricular tachycardia (pvt), asystole, and pulseless electrical activity (pea). ventricular tachycardia ventricular fibrillation (vf): disorganized and rapid quivering of the ventricles pulseless ventricular tachycardia (pvt): organized wide qrs complexes with no pulse asystole: no cardiac electrical activity, ecg shows a flat lineasystole pulseless electrical activity (pea): no pulses but ecg shows organized electrical activity (not vf or asystole); not a specific rhythm management chest compressions treatment of pediatric cardiac arrest follows the american heart association's (aha) pediatric cardiac arrest algorithm. the goals of treatment are to obtain return of spontaneous circulation (rosc), meaning that the heart starts working on its own. manual defibrillator once cardiac arrest is recognized, high quality cpr needs to be started immediately. after starting chest compressions, the provider should (1) give ventilations (via bag mask) and oxygen, (2) attach monitor/defibrillator pads or ecg electrodes to the child so that defibrillations (aka shocks) can be given if needed, and (3) establish vascular access (iv, io). attaching the defibrillator and establishing vascular access should not interrupt chest compressions. automated external defibrillator (aed) once the monitor/defibrillator is connected, the provider should assess the heart rhythm. of the 4 cardiac arrest rhythms, vf and pvt are shockable rhythms and asystole and pea are unshockable rhythms. shockable rhythms are rhythms that can improve with a shock and thus, should receive a shock. unshockable rhythms are rhythms that won't improve with a shock and thus, should not receive a shock. the monitor/defibrillator will either tell the providers if the rhythm is shockable (automated external defibrillators (aed)) or the providers will be able to read the ecg and determine for themselves if the rhythm is shockable (manual defibrillators). if shockable, give a shock then resume cpr. if not shockable, continue cpr, give epinephrine, and consider an advanced airway. after every 2 minutes of giving cpr the provider should reassess the patient's heart rhythm to see if it is shockable or unshockable, and give a shock if it is shockable. this 2 minute cycle of cpr and rhythm assessment should continue until it is determined by the providers that further management is unlikely to save the patient. for patients with shockable rhythms who haven't achieved rosc, providers can give epinephrine after 2 shocks and amiodarone or lidocaine after 3 shocks. throughout cpr and rhythm assessments, the providers should be treating any suspected reversible causes of cardiac arrest (h's and t's listed above). defibrillations/shocks first shock should be 2 j/kg second shock should be 4 j/kg all other shocks should be ≥ 4 j/kg with max of 10 j/kg medicines that can be given during treatment of cardiac arrest are listed below. the doses listed below are for iv/io medicationa. medications via endotracheal tube (et) are often given at higher doses. epinephrine: 0.01 mg/kg every 3–5 minutes with max single dose of 1 mg amiodarone: 5 mg/kg initially, can repeat 2 more times (total of 3 doses), max of 300 mg per dose, max 15 mg/kg, given for refractory vf and pvt lidocaine: 1 mg/kg initially with continuous infusion of 20-50 mcg/kg/min after, given for refractory vf and pvt magnesium sulfate: 25–50 mg/kg diluted in 10 ml d5w (5% dextrose) and infused over 1–2 minutes, max 2g per dose, given for pulseless torsades de pointes (a type of ventricular tachycardia) arrhythmias pals providers should be able to identify and treat different types of abnormal pediatric heart rhythms including bradyarrhythmias, tachyarrhythmias, and cardiac arrest rhythms (discussed above). in defining heart rates that are too slow or too fast, it is important to understand the ranges of pediatric heart rates by age. normal ranges of pediatric heart rates change with age, with heart rates being faster closer to birth and slower closer to adulthood. bradyarrythmias bradycardia is defined as a slow heart rate for a child's age. bradycardia associated with signs of shock (altered mental status, hypotension, etc.) can be an early warning sign for cardiac arrest. signs of bradycardia include fatigue, confusion, dizziness, and lightheadedness. possible causes of bradycardia include hypoxia, hypothermia, and certain medications. av block types of bradyarrhythmias sinus bradycardia: normal rhythm, slow rate atrioventricular block first degree: prolonged pr interval (> 0.20 seconds) second degree mobitz type i (wenckebach): progressive lengthening of pr interval then dropped beat (p wave with no qrs) mobitz type ii: equal pr intervals with intermittent dropped beats (p wave with no qrs) third degree: complete dissociation between p wave and qrs complex, atria and ventricles are beating independent of one another management providers should follow the aha's pediatric bradycardia with a pulse algorithm. as always, provides need to support airway, breathing, and circulation and begin cpr if needed. bradyarrythmias with signs of shock can be treated with epinephrine and atropine in order to increase heart rate. if medications aren't helping, providers can consider cardiac pacing. epinephrine: 0.01 mg/kg every 3–5 minutes atropine: 0.02 mg/kg, can repeat one time, max dose 0.5 mg, min dose of 0.1 mg tachyarrhythmias tachycardia is defined as a fast heart rate for a child's age. signs of tachycardia are similar to bradycardia but also include palpitations, decreased feeding/eating, and irritability. tachyarrhythmias are fast abnormal heart rhythms. types of tachyarrhythmias supraventricular tachycardia (svt)sinus tachycardia: normal rhythm (normal p waves), fast rate, heart rate usually < 220 bpm (beats per minute) in infants and < 180 bpm in kids supraventricular tachycardia (svt): abnormal rhythm (abnormal p waves), fast rate, originates above the ventricles, heart rate usually > 220 bpm in infants and > 180 bpm in kids, narrow qrs (< 0.09 seconds) ventricular tachycardia (vt): fast rate, originates in the ventricles, wide qrs (> 0.09 seconds) management providers should follow the aha's pediatric tachycardia with a pulse algorithm. as always, provides need to support airway, breathing, and circulation and begin cpr if needed. management of tachyarrhythmias depends on if the child is stable or unstable (experiencing cardiopulmonary compromise: signs of shock, hypotension, altered mental status). unstable tachyarrhythmia is treated with synchronized cardioversion - initially 0.5-1 j/kg but can increase to 2 j/kg if smaller dose is not working. stable tachyarrhythmia treatment is subcategorized based on narrow qrs vs. wide qrs. if narrow qrs/ svt, perform vagal maneuvers and give adenosine. if wide qrs/ vt with regular rhythm and monomorphic qrs, the provider can give adenosine and should consult pediatric cardiology for recommendations. adenosine: first dose 0.1 mg/kg with max 6 mg, second dose 0.2 mg/kg with max 12 mg criticism peta has criticized the use of animals in pals training which the organization calls "cruel and unnecessary". peta says that hundreds of pals training centers have begun using simulators in response to concerns regarding the animals' welfare. the american heart association neither endorses nor requires the use of animals in intubation training.