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PALS Written 2006 Precourse Self- 1 Assessment
PALS Written 2006 Precourse Self-Assessment
ECG Rhythm Identification Answer Sheet
Pediatric Rhythms (core PALS rhythms A to H; non-core rhythms I to M): A. Normal sinus rhythm B. Sinus tachycardia C. Sinus bradycardia D. Supraventricular tachycardia (SVT) E. Wide-complex tachycardia; presumed ventricular tachycardia (monomorphic) F. Ventricular fibrillation (VF) G. Asystole H. Pulseless electrical activity (PEA) I. SVT converting to sinus rhythm with adenosine administration J. Wide-complex tachycardia (in a child with known aberrant intraventricular conduction; this is SVT with aberrant conduction) K. First-degree AV block L. Torsades de pointes (polymorphic ventricular tachycardia) M. VF converted to organized rhythm after successful shock delivery (defibrillation) Rhythms 1 to 8: Core PALS Rhythms (select single best answer from rhythms A to H) Rhythm 1 (clinical clue: heart rate 214/min) Correct answer is E: Wide-complex tachycardia; presumed ventricular tachycardia (monomorphic) Pediatric ECG tip: Ventricular tachycardia is a sustained series of wide QRS
PALS Written 2006 Precourse Self- 2 Assessment complexes (ie, ventricular depolarizations) typically at a rate of at least 120/min. This VT can be further classified as monomorphic because all complexes have the same appearance. If
PALS Written 2006 Precourse Self- 4 Assessment
Rhythm 3 (clinical clues: age 8 years; heart rate 50/min)
Correct answer is C: Sinus bradycardia. Pediatric ECG tip: Sinus bradycardia is characterized by a sinus rhythm with a rate that is slower than normal for the patient’s age. P waves and QRS complexes are usually normal in appearance; the QRS is narrow. For further information: see the PALS Provider Manual Chapter 6: Recognition and Management of Bradyarrhythmias and Tachyarrhythmias.
Rhythm 4 (clinical clue: no detectable pulses)
Correct answer is G: Asystole Pediatric ECG tip: Asystole is the absence of ventricular depolarization (ie, cardiac standstill). It may be preceded by an agonal (usually wide- complex) bradyarrhythmia (see an example of this in Rhythm 2). When you observe this rhythm in a child who is unresponsive, apneic, and pulseless, you should begin compressions and ventilations (CPR) immediately. Of course, if you are uncertain whether the rhythm is asystole, confirm the flat-line rhythm in 2 perpendicular leads but do not delay CPR for an unresponsive, apneic child.
PALS Written 2006 Precourse Self- 5 Assessment For further information: see the PALS Provider Manual Chapter 7: Recognition and Management of Cardiac Arrest.
Rhythm 5 (clinical clue: no consistent heart rate detected; no detectable
pulses)
Correct answer is F: Ventricular fibrillation Pediatric ECG tip: Ventricular fibrillation (VF) is characterized by a rapid, irregular waveform of varying size and configuration. VF begins as a coarse, irregular deflection and then deteriorates to a fine, irregular pattern. If no CPR and no shocks are provided, this rhythm will eventually progress to asystole. For further information: see the PALS Provider Manual Chapter 7: Recognition and Management of Cardiac Arrest.
Rhythm 6 (clinical clues: age 3 years; heart rate 188/min)
Correct answer is B: Sinus tachycardia Pediatric ECG tip: Sinus tachycardia is characterized by a normal sequence of
PALS Written 2006 Precourse Self- 7 Assessment formation and conduction with a rate faster than normal for the patient’s age. P waves precede each QRS complex; the QRS is typically narrow. For further information: see the PALS Provider Manual Chapter 6: Recognition and Management of Bradyarrhythmias and Tachyarrhythmias.
Rhythm 7 (clinical clue: heart rate 300/min)
Correct answer is D: Supraventricular tachycardia
Pediatric ECG tip: Supraventricular tachycardia is characterized by the
following: no beat-to-beat variability with activity or stimulation; heart
rate typically >220/min in infants and >180/min in children; absent or
abnormal P waves; and usually narrow QRS complexes. Wide-complex
tachycardia with poor perfusion is probably ventricular in origin, but
one pediatric case series and clinical experience note that it may be
supraventricular with aberrant intraventricular conduction.
For further information: see the PALS Provider Manual Chapter 6: Recognition and Management of Bradyarrhythmias and Tachyarrhythmias.
PALS Written 2006 Precourse Self- 8 Assessment
Rhythm 8 (clinical clues: age 8 years; heart rate 75/min)
Correct answer is A: Normal sinus rhythm Pediatric ECG tip: All rhythms originating in the sinoatrial (sinus) node are characterized by the following: P waves preceding each QRS complex; regular PR interval; all of the P waves are upright and have the same appearance. The QRS complexes are narrow in this strip. In normal sinus rhythm, the heart rhythm is regular, heart rate is normal for the patient’s age, and the rate changes with activity.
Rhythms 9 to 13: Non-core Rhythms
Rhythm 9 (clinical clue: initial rhythm associated with no detectable pulses) Correct answer is M: Ventricular fibrillation converted to organized rhythm after successful shock delivery (defibrillation) Pediatric ECG tip: The probability of successful defibrillation is greater the higher the amplitude of the VF waveform (ie, when the VF waveform is “coarse”). The probability of successful defibrillation decreases as the amplitude of the VF waveform decreases (ie, the VF waveform becomes more “fine”). Fine VF is consistent with an ischemic myocardium that has exhausted its oxygen supply and energy substrates. For further information: see PALS Provider Manual Chapter 7: Recognition and Management of Cardiac Arrest
PALS Written 2006 Precourse Self- 1 Assessment
QT interval cannot be measured during the tachycardia.) Even if the
patient with torsades has pulses
PALS Written 2006 Precourse Self- 1 Assessment
initially, the patient will quickly become pulseless. Any pulseless VT is
a cardiac arrest rhythm, and it is treated with CPR and attempted
defibrillation. Torsades is also treated with IV magnesium according to
the VF/pulseless VT portion of the PALS Pulseless Arrest Algorithm.
For further information: see the PALS Provider Manual Chapter 6: Recognition and Management of Bradyarrhythmias and Tachyarrhythmias and Chapter 7: Recognition and Management of Cardiac Arrest. Rhythm 12 (clinical clue: heart rate 150/min) Correct answer is J: Wide-complex tachycardia (in child with known aberrant intraventricular conduction, this is SVT with aberrant conduction) Pediatric ECG tip: The wide QRS complex seen in this strip is supraventricular tachycardia with aberrant intraventricular conduction, which may be due to abnormal bundle branch conduction (eg, preexisting bundle branch block or rate-related malfunction) or abnormal accessory pathway AV conduction (eg, as encountered in preexcitation syndromes such as that described by Wolff, Parkinson, and White). Without a 12-lead ECG or a history of known aberrant conduction, it is impossible to distinguish this rhythm from ventricular tachycardia. For this reason the provider should assume that a wide-complex tachycardia is VT unless the child is known to have aberrant conduction. Treatment is dictated by the child’s clinical condition (poor perfusion versus adequate perfusion). For further information: see the PALS Provider Manual Chapter 6: Recognition and Management of Bradyarrhythmias and Tachyarrhythmias****.
PALS Written 2006 Precourse Self- 1 Assessment
Pharmacology Answer Sheet
1. You are called to help resuscitate an infant with severe symptomatic bradycardia associated with respiratory distress. The bradycardia persists despite establishment of an effective airway, oxygenation, and ventilation. There is no heart block present. Which of the following is the first drug you should administer? A. Atropine B. Dopamine C. Adenosine D. Epinephrine
Correct answer is D. Epinephrine, a catecholamine with direct effects at the β-
adrenergic receptor, is the first drug recommended for severe
symptomatic bradycardia unresponsive to establishment and support of
the airway, oxygenation, and ventilation. Epinephrine is preferred in
this setting because it more effectively improves the heart rate in a
hypoxic-ischemic myocardium, which is the most common cause of
severe symptomatic bradycardia in children.
Answer A is incorrect. Atropine is indicated only if you suspect that the bradycardia is vagally induced or associated with heart block. Note that some drug toxicities produce increased vagal tone (eg, digoxin overdose). Primary atrioventricular (AV) block is another indication for using atropine preferentially over epinephrine in the treatment of symptomatic bradycardia. Answer B is incorrect. Dopamine is not included in the PALS treatment algorithm for severe symptomatic bradycardia. It takes time to prepare a dopamine infusion. Answer C is incorrect. Adenosine blocks AV conduction and is used to treat supraventricular tachycardia. It is not recommended for the treatment of severe symptomatic bradycardia. For further information: see the PALS Provider Manual Chapter 6: Recognition and Management of Bradyarrhythmias and Tachyarrhythmias, Chapter 9: Pharmacology, and the PALS Course Guide Part 10: Pharmacology.
2. Which of the following statements about the effects of epinephrine during attempted resuscitation is true? A. Epinephrine decreases peripheral vascular resistance and reduces myocardial afterload so that ventricular contractions are more effective B. Epinephrine improves coronary artery perfusion pressure and stimulates spontaneous contractions when asystole is present C. Epinephrine is contraindicated in ventricular fibrillation because it increases myocardial irritability D. Epinephrine decreases myocardial oxygen consumption
PALS Written 2006 Precourse Self- 1 Assessment Correct answer is B. Epinephrine improves coronary artery perfusion pressure and myocardial oxygen delivery during CPR by increasing peripheral vascular resistance and thus aortic diastolic pressure. Recall that coronary perfusion pressure is determined by the difference between aortic end-diastolic pressure and right atrial end-diastolic pressure. Epinephrine also stimulates spontaneous cardiac contractions through its β- adrenergic agonist effects, so it may restore cardiac activity when asystole is
present. Increases in heart rate, cardiac contractility, and systemic
vascular resistance increase myocardial oxygen demand.
Answer A is incorrect. Epinephrine increases peripheral vascular resistance, ventricular afterload, and oxygen demand. Answer C is incorrect. Epinephrine is useful in the treatment of ventricular fibrillation. It increases the coarseness of ventricular fibrillation, which likely reflects improved coronary artery perfusion, thereby enhancing the potential for termination of ventricular fibrillation by attempted defibrillation. Answer D is incorrect. Epinephrine increases myocardial oxygen consumption. Although epinephrine-induced elevation of coronary artery perfusion pressure during chest compressions enhances delivery of oxygen to the heart, oxygen consumption is increased, not decreased. For further information: see the PALS Provider Manual Chapter 9: Pharmacology, and the PALS Course Guide Part 10: Pharmacology.
3. General assessment of a 2-year-old female reveals her to be alert with mild breathing difficulty during inspiration and pale skin color. On primary assessment, she makes high-pitched inspiratory sounds (mild stridor) when agitated; otherwise her breathing is quiet. Her SpO2 is 92% in room air, and she has mild inspiratory intercostal retractions. Lung auscultation reveals transmitted upper airway sounds with adequate distal breath sounds bilaterally. Which of the following is the most appropriate initial therapy intervention for this child? A. Perform immediate endotracheal intubation B. Administer an IV dose of dexamethasone C. Nebulize 2.5 mg of albuterol D. Administer humidified supplementary oxygen as tolerated and continue evaluation Correct answer is D. This child is not in acute distress and has no clinical evidence of respiratory failure. Therefore, the most appropriate intervention is to provide humidified oxygen as tolerated and observe the child to determine if she improves, deteriorates, or stays the same. Answer A is incorrect. This child does not meet the criteria for intubation. If you determine that the child has upper airway obstruction and cannot maintain an airway or if the child demonstrates signs of fatigue or respiratory failure, then endotracheal intubation is
PALS Written 2006 Precourse Self- 1 Assessment high oxygen flow rate of 10 to 15 L/min, stable inspired oxygen concentrations
40% cannot be reliably provided with a face tent.
PALS Written 2006 Precourse Self- 1 Assessment
5. Which of the following statements about endotracheal drug administration is true? A. Endotracheal drug administration is the preferred route of drug administration during resuscitation because it results in predictable drug levels and drug effects B. Endotracheal doses of resuscitation drugs in children have been well established and are supported by evidence from clinical trials C. Intravenous drug doses for resuscitation drugs should be used whether you give the drugs by the IV, intraosseous (IO), or the endotracheal route D. Endotracheal drug administration is the least desirable route of administration because this route results in unpredictable drug levels and effects Correct answer is D. Endotracheal (ET) drug administration is the least desirable route of resuscitation drug administration because optimal doses are unknown and this route results in unpredictable drug levels and effects. In fact, poor absorption of epinephrine by ET route may result in relatively low plasma concentration of epinephrine during resuscitation. Evidence from animal models suggests that the low epinephrine plasma concentrations following ET administration may result in preferential stimulation of β 2 -adrenergic receptors (producing vasodilation) rather than the α-adrenergic receptors that would produce the vasoconstriction needed during resuscitation. Answers A and B are incorrect. There is limited clinical evidence about optimal drug doses to be administered by the ET route to produce specific drug concentrations and effects. Answer C is incorrect. Although evidence is limited, it is clear that higher doses than those used for IV/IO route of administration should be used when drugs are administered by ET route. For further information: see the PALS Provider Manual Chapter 7: Recognition and Management of Cardiac Arrest, Chapter 9: Pharmacology, and the PALS Course Guide Part 10: Pharmacology. 6. Which of the following statements most accurately reflects the PALS recommendations for the use of magnesium sulfate in the treatment of cardiac arrest? A. Magnesium sulfate is indicated for VF refractory to repeated shocks and amiodarone or lidocaine B. Routine use of magnesium sulfate is indicated for shock-refractory monomorphic VT C. Magnesium sulfate is indicated for torsades de pointes or suspected hypomagnesemia D. Magnesium sulfate is contraindicated in VT associated with an abnormal QT interval during the preceding sinus rhythm Correct answer is C. Acting as an antiarrhythmic agent, magnesium sulfate is the drug of choice for treatment of torsades de pointes (“twisting of the
PALS Written 2006 Precourse Self- 1 Assessment Answer A is incorrect. Magnesium sulfate is not recommended for VF refractory to repeated shocks, amiodarone, or lidocaine. There is insufficient evidence to recommend the routine use of magnesium sulfate in the treatment of pediatric cardiac arrest. Answer B is incorrect. Routine use of magnesium sulfate is not recommended for shock- refractory monomorphic VT. Two observational studies in adults, however, showed that magnesium alone is effective in the treatment of polymorphic VT (eg, torsades de pointes) in patients with prolonged QT interval. Answer D is incorrect. Magnesium sulfate is indicated in VT associated with a prolonged QT interval during the sinus rhythm that preceded the development of torsades de pointes. Characteristically torsades de pointes is associated with a markedly prolonged baseline QT interval before the onset of the arrhythmia. Note that the QT interval must be evaluated during sinus rhythm and cannot be measured during an episode of ventricular tachycardia. For further information: see the PALS Provider Manual Chapter 6: Recognition and Management of Bradyarrhythmias and Tachyarrhythmias, Chapter 7: Recognition and Management of Cardiac Arrest, Chapter 9: Pharmacology, and the PALS Course Guide Part 10: Pharmacology.
7. You enter a room to perform a general assessment of a previously stable 10-year- old male and find him unresponsive and apneic. A code is called and bag-mask ventilation is performed with 100% oxygen. The cardiac monitor shows a wide- complex tachycardia. The boy has no detectable pulses. You deliver an unsynchronized shock with 2 J/kg. The rhythm check after 2 minutes of CPR reveals VF. You then deliver a shock of 4 J/kg and resume immediate CPR beginning with compressions. A team member had established IO access, so you give a dose of epinephrine, 0.01 mg/kg (0.1 mL/kg of 1:10,000 dilution) IO when CPR is restarted after the second shock. At the next rhythm check, persistent VF is present. You administer a 4 J/kg shock and resume CPR. Based on the PALS Pulseless Arrest Algorithm, what are the next drug and dose to administer when CPR is restarted? A. Epinephrine 0.1 mg/kg (0.1 mL/kg of 1:1,000 dilution) IO B. Atropine 0.02 mg/kg IO C. Amiodarone 5 mg/kg IO D. Magnesium sulfate 25 to 50 mg/kg IO Correct answer is C. The data supporting the use of amiodarone in the treatment of life-threatening ventricular arrhythmias in children is extrapolated from adult studies showing short-term beneficial effects for treatment of shock-refractory VF or VT. In addition, amiodarone has been reported to be effective in the treatment of atrial and ventricular arrhythmias in children. Amiodarone is recommended as part of the treatment of shock-refractory or recurrent VT. Amiodarone inhibits -
PALS Written 2006 Precourse Self- 2 Assessment adrenergic and -adrenergic receptors, producing vasodilation and AV nodal suppression (ie, impaired conduction through the AV node). Amiodarone also inhibits the outward potassium current, thereby
