Cardiovascular System II Cardiovascular System II Objectives • Present the clinical features and emergency management of cardiovascular disorders, including: – Diagnose and treat rhythm disturbances. – Detect and treat cardiomyopathy. – Treat shock. – Create differential diagnosis and management plan for syncope. Case Study 1: “Not Breathing” A 10-day-old male infant is brought to ED for not breathing and color change. The child was 3 weeks premature, and was discharged from hospital 3 days ago with an apnea monitor. Decreased activity since discharge. Poor feeding today. Instructor Information Begin discussion of assessment and management of a patient with cardiopulmonary failure. The PAT is as follows: • Appearance: Abnormal • Breathing: Abnormal • Circulation: Abnormal Vital signs include: • Heart rate: 220 bpm • Respiratory rate: 14 breaths/min • Blood pressure: 55/36 mm Hg • Weight: 3.5 kg (birth weight 3.7 kg) • Oxygen saturation: 88% on room air Cardiovascular System II 1 Cardiovascular System II Initial assessment: • A: Patent without evidence of obstruction • B: Nonlabored but diminished respiratory rate • C: Mottled, cool, distal cyanosis, tachycardic and weak pulse • D: Weak cry, nonfocal exam • E: Normothermic, no evidence of trauma, fontanel flat Detailed physical exam: • Head/Neck: No abnormalities • Heart: Tachycardia, no murmurs heard • Lungs: Decreased breath sounds • Abdomen: Liver 2 finger breadths below RCM • Neurologic: Weak cry, lethargic, poor interaction, responsive to pain and contact • Extremities: Cyanotic, cool upper and lower extremities Key Questions What is your general impression of this patient? Categorize this patient into one of the following categories: • Stable • Respiratory Distress • Respiratory Failure • Shock • Primary CNS Dysfunction • Cardiopulmonary Failure/Arrest Core Knowledge Points—General Impression Cardiopulmonary failure because all arms of the PAT are abnormal. Patient appearance is lethargic but responsive, with inadequate respirations and tachycardia; mottling with distal cyanosis. Key Questions What are your initial management priorities? Critical Actions Check ABCs. Open airway. Give 100% oxygen by BMV, or perform endotracheal intubation. Cardiovascular System II 2 Cardiovascular System II Check rhythm on cardiac monitor. Obtain vascular access. Obtain blood glucose prn. Check rectal temperature. Core Knowledge Points—Tachyarrhythmias Tachyarrhythmias: • Wide complex – Ventricular tachycardia (rare rhythm in children but if wide need to consider of ventricular origin) – Supraventricular tachycardia (SVT) with aberrancy • Narrow complex – Sinus tachycardia (rates usually < 220) – SVT (Rates usually > 220) Clinical features can be varied: • Palpitations in verbal children • Shock in any age • Generalized symptoms of malaise and weakness Diagnostic studies may include: • Cardiac monitor, ECG, sepsis evaluation if young infant who has signs and symptoms suggestive of infection • Chest radiograph, echocardiogram Management includes ABCs and stabilization. Core Knowledge Points—Dysrhythmias The pediatric patient has 3 basic types of pathologic rhythm disturbances, which include fast pulse (tachyarrhythmia), slow pulse (bradyarrhythmia), and absent pulse (pulseless) (Table 4-3 in the APLS textbook). These can be further divided into 7 classifications based on their anatomic function. Dysrhythmias may be the cause of impaired cardiac function leading to cardiac arrest. Occult dysrhythmias (e.g., prolonged QT syndrome, Wolf-Parkinson-White syndrome, etc.) may present with intermittent severe symptoms (e.g., palpitations or sudden death). Cardiovascular System II 3 Cardiovascular System II Clinical features—consider the following symptoms: • Intermittent, paroxysmal presence of symptoms • Dramatic onset and change in condition • Sudden onset of symptoms with little or no prodrome • Presentation of dysrhythmias can range from stable to cardiopulmonary arrest. — Infant or child may show subtle signs of major physiological derangement. Core Knowledge Points—Distinguishing SVT from ST Sinus Tachycardia (ST) Supraventricular Tachycardia (SVT) History Fever, sepsis, dehydration, Intermittent, paroxysmal in onset hemorrhage, hypovolemia, precedes ECG ST rate is less than 2x normal SVT rate at or greater than 2x normal rate rate for age. Rate varies with for age. Minimal or no rate change with activity. activity. Supraventricular tachycardia (SVT) history is intermittent, paroxysmal, with sudden onset. Sinus tachycardia (ST) history suggests sepsis, dehydration, hemorrhage, hypovolemia. SVT ECG steady rate at or greater than 2x normal rate for age. ST rate is less than 2x normal rate for age. Minimal or no rate change with activity with SVT. SVT characteristics (versus sinus tachycardia): • Heart rate is >2 times normal rate for age. • Rhythm is steady. • P waves are absent. • History is not suggestive of volume depletion or sepsis. Core Knowledge Points—Diagnostic Studies Radiology studies include chest radiographs; it is important to look for signs of structural congenital heart disease, congestive heart failure (due to a prolonged dysrhythmia), or signs of infection (pneumonia). Laboratory tests should ALWAYS include a blood glucose check to exclude hypoglycemia in any child with abnormal mental status. Differential diagnoses may include: • Hypoglycemia Cardiovascular System II 4 Cardiovascular System II • Sepsis • Hyperthyroidism • Volume depletion • Catastrophic illness, e.g., CNS, GI trauma (abuse) • Metabolic disease Critical Actions Manage ABCs. Get baseline ECG. Obtain vascular access. For SVT (see AHA algorithm): • Vagal maneuvers for stable SVT • Adenosine: 100 mcg/kg bolus, increase to 200 mcg/kg (maximum first dose is 6 mg, maximum second and subsequent doses 12 mg) – given for stable SVT if unresponsive to vagal maneuvers or for unstable SVT if IV access is immediately available. • Cardioversion for unstable SVT (poor perfusion) • Procainamide or amiodarone to be considered if possible of ventricular origin; that is QRS >0.08 seconds • Digoxin to slow rate if cardioversion unsuccessful • Cardiology consultation Cardiovascular System II 5 Cardiovascular System II The PALS algorithm for tachycardia (sinus tachycardia, SVT, and ventricular tachycardia) with POOR PERFUSION is shown below: Tachycar dia Managem ent Management is driven by presence or absence of poor perfusion. Sinus tachycardia is not an arrhythmia but its etiology must be determined. Provide ventilation and oxygenation for all patients in cardiopulmonary arrest, as the primary etiology is often respiratory failure. Patients such as this should be transported to a pediatric referral center after stabilization. Transport issues include: • ALS transport with monitoring and IV access • Treatment plan for possible en route for recurrence – including potential for cardioversion • Consult the accepting pediatric cardiologist Cardiovascular System II 6 Cardiovascular System II Documentation considerations include: • Always try to get baseline 12-lead ECG before and after cardioversion. • Treatment record from prehospital and ED care • Emergency Medical Treatment and Active Labor Act (EMTALA) compliance Risk management considerations include: • Always check blood glucose. • Assure rapid triage of infants in distress. • Do not hesitate to cardiovert when child is unstable. Reversible non-cardiac causes of dysrhythmias: Four H’s: • Hypoxemia • Hypovolemia • Hypothermia • Hyper/Hypokalemia and metabolic disorders Reversible non-cardiac causes of dysrhythmias: Four T’s: • Tamponade (cardiac) • Tension pneumothorax • Toxins/poisons/drugs • Thromboembolism Case Development ECG reveals SVT. Infant receives BMV ventilation. Preparations made to cardiovert but rapid IV access is obtained. Adenosine 100 mcg/kg IV push is given followed by normal saline bolus (flush). Sinus rhythm returns. BMV is discontinued as infant’s condition stabilized. 100% oxygen nonrebreather mask is placed. Sinus rhythm returns. ECG does not show early repolarization (e.g., WPW). Case Study 2: “Unresponsive Episodes” 2-year-old girl passed out eating cereal; awoke after 5 minutes. She was stiff with eyes rolled back for approximately 5 minutes. Minimal period of sleepiness, now awake and alert; no retractions; skin color is normal. Cardiovascular System II 7 Cardiovascular System II Instructor Information Begin discussion of assessment and management of a patient with syncope. The PAT is as follows: • Appearance: Normal • Breathing: Normal • Circulation: Normal Initial assessment: ABCDEs: Normal. Vital signs include: • Heart rate: 120 bpm • Respiratory rate: 24 breaths/min • Blood pressure: 80/60 mm Hg • Temperature: 37.7°C • Weight: 12 kg • Oxygen saturation: 99% Focused history: • Three similar episodes; two associated with “temper tantrums.” • PMH: Negative • FH: Negative for sudden death Key Questions What is your general impression of this patient? Categorize this patient into one of the following categories: • Stable • Respiratory Distress • Respiratory Failure • Shock • Primary CNS Dysfunction • Cardiopulmonary Failure/Arrest Core Knowledge Points—General Impression The patient presents with syncope and normal appearance on exam. She is in no distress and the exam is normal. Her history, however, is concerning and ominous. Cardiovascular System II 8 Cardiovascular System II Key Questions What are your initial management priorities? Core Knowledge Points—Syncope Syncope in young children is a serious symptom. Life-threatening causes must be