Monday Morning Medical Director’s Message

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: 

1. Heart Rate 
2. Pulse Quality 
3. Skin temperature and capillary refill time 
4. 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