Dr Yaskey is an Pediatric EMS Medical Director for UH Cleveland Medical Center Rainbow Babies and Childrens Hospital
Good morning,
This month, we will be discussing pediatric cardiac arrest and dysrhythmias. Pediatric cardiac arrest is uncommon in the prehospital setting. The primary cause of arrest in children is usually an asphyxia arrest situation that deteriorates into cardiac arrest. Although hypoxia leading to pulseless electrical activity (PEA) is the most common cause of pediatric arrest, a small percentage may demonstrate ventricular fibrillation (VF) or ventricular tachycardia (VT). Regardless of the type of cardiovascular emergency, early recognition and timely management can reduce the likelihood of serious morbidity or mortality.
While at the scene of the incident, ensure safety and note any significant findings that may be contributing factors to the situation as well as appropriate signs of child maltreatment.
Evaluating the Presenting Complaint
On arrival, determine the child’s presenting complaint and reference PAT:
Pediatric Assessment Triangle (PAT)
Appearance
Work of Breathing
Circulation
Appearance
First, assess the child’s appearance. A child with decreased core circulation from any cardiac compromise may have signs of poor brain perfusion. The abnormality in the child’s appearance will be variable, depending on the type of perfusion problem and the degree of circulatory insufficiency. Some abnormal features in the appearance of a child with decreased core circulation include:
lethargy or listlessness
decreased motor activity for infants
poor muscle tone
diminished interactivity with caregivers or the prehospital providers and the environment
inconsolability
poor eye contact
weak cry
work of breathing
If circulation to vital organs is decreased, the child’s respiratory rate will increase. “Effortless tachypnea,” or a fast respiratory rate without increased work of breathing, is a common, but non-specific sign of hemodynamic instability. It reflects the child’s attempt to blow off CO2 and reduce the metabolic acidosis created by decreased perfusion to cells.
Circulation
Next, assess the skin color of the child. This is difficult to interpret if the environmental temperature is low. Vasoconstriction (as a reflexive effort to preserve heat), will falsely alter skin findings, especially in infants. Disrobe the child and look for mottling, pallor, and cyanosis which reflects peripheral vasoconstriction or clamping on nonessential skin perfusion to maintain essential core circulation.
Primary Assessments: ABCDEs
After the PAT, perform the hands-on ABCDE assessment. The four other parts of the assessment of circulation are:
Heart Rate
Pulse Quality
Skin temperature and capillary refill time
Blood pressure
Heart Rate
Measure the heart rate by feeling the pulse for 30 seconds and then doubling the number. The radial or brachial sites are preferred sites to measure pulse rate in infants and children. The carotid pulse is hard to locate in infants. Femoral pulses are often easily palpable in neonates and infants. If a pulse is difficult to feel, determine heart rate by listening to the heart sounds directly with a stethoscope placed on the medial side of the child’s left nipple. Certain common medications may also alter heart rate (high and low). Stimuli that can cause tachycardia include pain, fever, fear, and agitation. Make sure to interpret heart rate in the context of overall signs of perfusion, age, presence or absence of noxious stimuli, medications, and observed trends. Although a single measurement of heart rate is usually of limited value in determining the degree of physiologic derangement, a trend of mounting tachycardia (a heart rate that is falling below the lower limits of normal) suggests a serious physiologic problem. Sustained tachycardia is a worrisome sign. Be extremely vigilant when the child has bradycardia, because this often indicates hypoxia and may be a sign of profound ischemia. Bradycardia is always a critical sign in a young child and reflects hypoxia or advanced shock.
Pulse Quality
The presence of a strong central pulse (carotid, femoral, brachial in infants) with a strong peripheral pulse (brachial, radial, or pedal in children) suggests a good blood pressure. A strong central pulse with a weak peripheral pulse indicates compensated shock. If a brachial pulse is not palpable, the child is probably hypotensive and hemodynamically unstable.
Skin Temperature and Capillary Refill Time (CRT)
Cool hands and feet may be normal, but cool proximal extremities reflect poor perfusion and shunting of blood to the core. CRT should be less than 2 seconds in a child who is not cold. Inadequate core perfusion results in peripheral vasoconstriction, which will manifest as cool skin and delayed CRT. Although CRT is a good test of circulation in children, it must be interpreted in the context of overall signs of perfusion.
Blood Pressure (BP)
An elevated BP value in a child is not clinically significant in the field, unless there isa history of hypertension, known renal disease or acute head injury. A true low BP is a sign of hemodynamic instability. The challenges in BP measurement in children in the prehospital setting include knowing when to get a BP reading, obtaining the BP correctly and interpreting it accurately.
The minimal acceptable systolic BP in a child older than 1– 9 years of age is determined with the following equation:
70 + (2 x years of age)
An infant younger than 1 year should have a systolic BP > 60.
Stay safe and keep up the great work.
Regina Yaskey, MD
Good morning,
This week, we will continue our discussion of pediatric cardiac assessment.
Let us start with SAMPLE components in a child with cardiovascular problems. The SAMPLE mnemonic stands for Signs/Symptoms, Allergies, Medications, Past medical problems, Last food or liquid, Events leading to the injury or illness.
Next, perform the OPQRST mnemonic to learn more about the patient’s pain:
THE OPQRST of Pain
O – Onset
Key Question: What were you doing when the pain / discomfort started?
P – Provocation / Palliation
Key Questions: What makes the pain / discomfort better or worse? What have you tried to reduce the symptoms? Did it work?
Support Questions: Has this ever happened before? If so, when?
Q – Quality
Key Question: What does your pain feel like?
Support Question: Can you describe it for me?
R – Region / Radiation
Key Question: Can you point with one finger to the main area of pain / discomfort?
Support Questions: Do you feel pain anywhere else? If so, can you show me or tell me where it is?
S- Severity
Key Question: How bad is the pain or chief complaint on a scale of 1 to 10, with 1 being no pain and 10 being extreme pain?
Support Questions: What is the worst pain you have ever experiences? How does this compare?
T – Time Frames
Key Question: When did you first notice the symptoms?
Support Questions: Have the symptoms been continuous? If not, has the feeling come and gone?
After the focused history, perform a focused examination of the heart, peripheral circulation and abdomen. Also, perform an ongoing assessment of all children with cardiovascular problems during transport, observing for changes while on the cardiorespiratory monitor. Remember that the patient’s status may change during transport, therefore observe and document any physiologic trends. We discussed the Pediatric Assessment Triangle (PAT) last week. Remember to use it (Appearance, Work of breathing, Circulation) to monitor effective perfusion and respiratory rate, heart rate, blood pressure, and pulse oximetry. Be prepared to increase the level of respiratory and cardiovascular support if the child worsens or fails to respond to treatment.
Next week, we will discuss cardiac dysrhythmias.
Have a great week and keep up the good work.
Regina Yaskey, MD
Good morning. This week we are discussing dysrhythmias and will start with bradycardia. In children, bradycardia usually represents hypoxia rather than a primary cardiac problem. It is a prearrest rhythm, and the prognosis is ominous if left untreated. Pulse oximetry, when available, will help determine the degree of hypoxia in the field. Causes of bradycardia include hypoxia, congenital heart block (which is a rare cause of bradycardia in infancy and early childhood), drug overdose (e.g. β-blockers, calcium channel blockers, digoxin, clonidine), vagal stimulation during medical procedures, gastric tube placement and elevated intracranial pressure.
It is important to note that bradycardia may also be a normal finding, especially in asymptomatic athletic students. If it is an isolated finding, without signs of hemodynamic instability, in a well perfused school-aged child or teenager, no treatment is necessary in the field. If a child has a heart rate below the normal range for age, evaluate carefully for signs of respiratory failure or shock. The Pediatric Assessment Triangle (PAT), ABCDE’s, plus a brief history will establish the likely cause, the severity of the problem, and the need for urgent treatment. If asymptomatic, consider no treatment (especially if it is an adolescent). If primary assessment demonstrates oxygenation, ventilation or perfusion abnormalities, provide 100% oxygen with BMV and transport. Epinephrine is the first-line drug. Give 0.1 mg/mL, 0.01 mg/kg or 0.1 mL/kg IV or IO every 3-5 minutes. If there is poisoning by cholinergic drugs (e.g. organophosphates) or an AV heart block, administer atropine 0.02 mg/kg IV or IO (max 0.5 mg). When oxygenation, ventilation, and drug therapy fail, consider external electrical cardiac pacing of the heart. Remember that epinephrine is given at a higher concentration of 1 mg/mL (0.1 mg/kg or 0.1 mL/kg) through the ETT. Atropine dose is also 2 -3 times the IV/IO dose (0.04 – 0.06 mg/kg).
Tachycardia may be a nonspecific sign of fear, anxiety, pain, or fever. It may also be life-threatening (hypoxia, cardiac abnormality, hypovolemia). Sinus tachycardia is the most common dysrhythmia in children. Treatment is generally limited to fluid administration, supplemental oxygen, pain medication, and transport. Use the PAT and ABCDEs to start your assessment. Always ask about a history of congenital heart disease and check for midline chest scars from surgery. Get an EKG if suspicion is high.
Remember that there are two characteristics in rhythm strip:
Heart Rate per minute
Width of the QRS complex
Narrow complex tachycardia is present if the QRS complex is ≦ 0.09 seconds (< 2 ¼ standard boxes on the rhythm strip)
Wide complex tachycardia is present If QRS complex is > 0.09 seconds (> 2 ¼ standard boxes on the rhythm strip)
In narrow complex tachycardia, P waves are present. The heart rate is greater than 220 beats/minute in infants, and less than 180 beats/minute in children. Causes are usually from non-cardiac conditions (e.g. hypoxia, hypovolemia, hypothermia, hypoglycemia, metabolic abnormalities, fear, pain, or serious trauma to the chest). There is no specific therapy needed, but can be treated with fluids, oxygen, splinting, analgesia, or sedation as indicated by the associated condition.
Supraventricular tachycardia (SVT) is ≥220 beats/minute in an infant and ≥180 beats/minute in a child. P waves are absent. If the child has no previous history of SVT, and is stable, transport to the ED. If the patient has a prior history of SVT and is stable, consider vagal maneuvers first (place crushed ice in a plastic bag, glove or washcloth, and apply firmly to mid face (cheeks and bridge of nose) for approximately 15 seconds, until the rhythm changes or the patient’s condition dictates immediate cessation of the procedure. Remember not to occlude the nose and avoid ocular pressure; only attempt a vagal maneuver once. There is controversy over whether ice to the face for SVT has not been evaluated for efficacy or safety in the prehospital setting, especially in children. Give adenosine at 0.1 mg/kg up to a max first dose of 6mg rapid IV or IO push and follow immediately with a 2 – 5 mL bolus of normal saline. Use the IV/IO nearest to the heart. Use a three-way stopcock if available. Double the dose of adenosine to 0.2 mg/kg (max 12 mg) if rhythm does not convert after the first try. If the patient has an abnormal PAT (poor pulse quality, abnormal cap refill and temp, hypotension), is in shock or is unconscious, administer synchronized electrical cardioversion at 0. 5 – 1 J/kg, up to 2 J/kg. If electrical therapy fails to convert the child to sinus rhythm, consider amiodarone (5 mg/kg over 20 – 60 minutes) or procainamide (15 mg/kg over 20 – 60 minutes) as per local EMS guidelines.
If a patient is conscious and has adequate perfusion, an HR >150 beats/minute and a QRS >0.09 seconds, they are probably in stable ventricular tachycardia (VT). Sinus tachycardia with a conduction abnormality (bundle branch block) may look like VT but usually occurs in a child with a history of heart disease or cardiac surgery. Likewise, SVT with aberrant conduction can result in a wide complex rhythm. If the child is stable, provide oxygen and transport to the ED. If the rhythm is VT, an antiarrhythmic can be used per EMS guidelines. If the child has VT and shows signs of poor perfusion, treat with synchronized electrical cardioversion (0.5 – 1 J/kg). If a second shock (2 J/kg) is unsuccessful, or if the tachycardia recurs quickly, consider amiodarone (5 mg/kg over 20-60 minutes) or procainamide (15 mg/kg over 30-60 minutes) per EMS protocol. Do not give amiodarone and procainamide together. Coadministration may increase the risk of new arrhythmias, including Torsades de Pointes, due to additive depressant effects on cardiac conduction, which could lead to excessive QT prolongation. If the child has VT and shock without a pulse, treat as pulseless VT/VF.
Next week, we will discuss pediatric cardiac arrest. Take care and stay safe.
Regina Yaskey, MD