PEDIATRIC CARDIOPULMONARY RESUSCITATION
Securing the Airway
The airway in infants and children is smaller, more variable in size, and more anterior than in the adult.
Mild extension of the head (sniffing position) opens the airway. Chin lift or jaw thrust maneuvers may relieve obstruction of the airway related to the tongue. Oral airways are not commonly used in pediatrics but may be useful in patients whose airway cannot be maintained manually. Oral airways are inserted with a tongue blade, as in adults.
A bag-valve-mask system is commonly used for ventilation. Minimum volume for ventilation bags for infants and children is 450 mL. The tidal volume necessary to ventilate children is 10 to 15 mL/kg. In emergency situations, however, observation of chest rise and auscultation of breath sounds will ensure adequate ventilation.
Endotracheal intubation is usually performed using a Miller (straight) blade with a properly sized tube. The internal diameter of the tube should be the same size as the end of the patient’s little finger. The formula 16 plus age in years divided by 4 gives approximate tube size. Uncuffed tubes are used in children up to 7 to 8 years.
Rapid Sequence Induction
Rapid sequence induction (RSI) is the administration of an intravenous anesthetic with a neuromuscular blocking agent to facilitate endotracheal intubation.
1.Prepare all equipment and supplies. A well functioning intravenous (IV) line must be in place. A cardiac monitor and oximetry should be used. The laryngoscope light source should be checked. Suction equipment should be on and immediately available.
2.Preoxygenate with 100% oxygen.
3.Lidocaine 1 mg/kg IV may be used in head trauma patients to prevent increased intracranial pressure (ICP). Atropine 0.02 mg/kg (minimum dose 0.1 mg) may be used to prevent reflex bradycardia in children under 5 years old.
4.Cricoid pressure should be applied before paralysis and maintained until intubation is accomplished.
5.Induction of anesthesia is accomplished using one of several drug choices, depending on the clinical situation and the experience of the physician. Sodium thiopental 3 to 5 mg/kg is most commonly used. Advantages of thiopental include rapid onset of action, safe use with increased ICP, and low cost. Disadvantages include histamine release, possible hypotension, and tissue necrosis if extravasated. Propofol 2 to 2.5 mg/kg is a rapid acting induction agent that is safe for increased ICP. Disadvantages include pain on injection and cost. Ketamine 0.5 to 2 mg/kg is a dissociative anesthetic that increases heart rate and has bronchodilating effects. It has been used in trauma with hypotension and in patients with asthma. Disadvantages include increased airway secretions, increased ICP, emergence reactions, and possible laryngospasm. Midazolam 0.05 to 0.2 mg/kg is a benzodiazepine that can be used for induction. One of the advantages is reversibility. Disadvantages include slower onset of action and possible cardiorespiratory depression.
6.Neuromuscular blockade is accomplished by using succinylcholine, vecuronium, or rocuronium. Succinylcholine (1.0 mg/kg if > 12 kg; 2.0 mg/kg if > 12 kg) is a depolarizing blocking agent that has a rapid onset (45 s) but short duration of action (3 to 5 min). Although producing reliable paralysis, it has several disadvantages: (a) hyperkalemia, it should not be used in burns, spinal cord injuries, chronic immobilization, crush injuries with significant muscle injury, or conditions predisposing to hyperkalemia; it has been associated with hyperkalemic arrest in children with underlying but undiagnosed myopathies; (b) malignant hyperthermia in susceptible individuals; (c) elevations in ICP and intraocular pressure; (d) bradycardia, particularly in infants (premedicate with atropine in children under 5 years to prevent this effect); (e) muscle fasciculations, which may be prevented by a defasciculating dose of a nondepolarizing agent before succinylcholine is given. The short duration of action of succinylcholine may be a particular advantage when a difficult airway is anticipated or when ongoing neurologic assessment is required. A fast acting nondepolarizing agent, such as vecuronium or rocuronium, may be chosen with the knowledge that the onset of action is slower and the duration of action much longer. Rocuronium 0.5 to 1.0 mg/kg is the fastest acting nondepolarizing agent, with onset in 55 to 75 s. The duration of action is 30 to 60 min. Vecuronium 0.1 to 0.3 mg/kg has an onset of 60 to 90 s and lasts 90 to 120 min.
7.Intubate the trachea and release cricoid pressure.
Vascular Access
Securing vascular access can be challenging in a critically ill child. Airway management is paramount in pediatric arrest and should not be delayed while obtaining vascular access. Vascular access is obtained in the most rapid, least invasive manner possible; peripheral veins (arm, hand, or scalp) are tried first. Intraosseous access is a quick, safe route for resuscitation medications and may be tried next in the critically ill infant. Percutaneous access of the femoral vein or access of the saphenous vein through cutdown can also be used, but is more time consuming.
The technique for insertion of the intraosseous line is as follows: the bone most commonly used is the proximal tibia. The anterior tibial tuberosity is palpated with the index finger, and the medial aspect of the tibia is grasped with the thumb. An imaginary line is drawn between the two, and the needle is inserted 1 cm distal to the midpoint of this line. A bone marrow needle is most commonly used; if a bone marrow needle is not available, an 18 gauge spinal needle can be used but is prone to bending. With sterile technique, the needle is inserted in a slightly caudal direction until the needle punctures the cortex. The stylet is removed, and marrow is aspirated to confirm placement. Fluids or drugs (including glucose, epinephrine, dopamine, anticonvulsants, and antibiotics) may then be administered as they are through a normal IV line.
Fluids
In shock, IV isotonic fluid (i.e., normal saline solution) boluses of 20 mL/kg should be given as rapidly as possible and should be repeated, depending on the clinical response. If hypovolemia has been corrected and shock or hypotension persist, a pressor agent should be considered.
Drugs
The indications for resuscitation drugs are the same for children as in adults. Drug dose calculations are a problem particular to pediatrics. Using a drug dosage chart or Broselow tape will reduce dosage errors. The Broselow tape is a length based system for estimating the weight of children in emergency situations. The tape has drug dosages, equipment sizes, and fluid volumes displayed according to patient size. A drug dose and equipment size chart or Broselow tape should be readily accessible in emergency care settings. Equipment should be stored so that appropriate sizes are readily accessible.
The rule of sixes may be used to quickly calculate continuous drug infusions (e.g., dopamine, dobutamine, etc.). The calculation is 6 mg times weight in kilograms; fill to 100 mL with D5W. The infusion rate in milliliters per hour equals the microgram per kilogram per minute rate (i.e., an infusion running at 1 mL/h = 1 µg/kg/min, or 5 mL/h = 5 µg/kg/min).
Epinephrine is the only drug proven effective in cardiac arrest. It is indicated in pulseless arrest and in slow rates that are hypoxia induced and unresponsive to oxygenation and ventilation. If the initial dose of epinephrine (0.01 mg/kg of a 1:10,000 concentration) is not effective, high-dose epinephrine is recommended (0.1 to 0.2 mg/kg of a 1:1000 concentration) subsequently. Primary cardiac causes of bradycardia are rare and may be treated with atropine 0.02 mg/kg (minimum dose 0.1 mg) after adequate oxygenation and ventilation are ensured.
Sodium bicarbonate is no longer recommended as a first line resuscitation drug. It is recommended only after epinephrine administration has been ineffective or as guided by arterial blood gas measurements. Calcium is not recommended in routine resuscitation but may be useful in hyperkalemia, hypocalcemia, and calcium channel blocker overdose.
Dysrhythmias
Dysrhythmias in infants and children are most often the result of respiratory insufficiency or arrest, not of primary cardiac causes, as in adults. Careful attention to oxygenation and ventilation are, therefore, cornerstones of dysrhythmia management in pediatrics.
The most common rhythm seen in pediatric arrest situations is bradycardia leading to asystole. Oxygenation and ventilation are often sufficient in this situation; epinephrine may be useful if the condition is unresponsive to ventilation.
After the arrest situation, the most common dysrhythmia is supraventricular tachycardia (SVT). It presents with a narrow-complex tachycardia with rates between 250 and 350 beats per minute. Adenosine 0.1 mg/kg given through a well functioning IV line as close to the central circulation as possible followed by brisk saline flush is the recommended treatment for stable SVT in children. Treatment of the unstable patient with SVT is synchronized cardioversion (¼ to ½ J/kg).
It is sometimes difficult to distinguish between a fast sinus tachycardia and SVT. Small infants may have sinus tachycardia with rates above 200/beats per minute. Patients with sinus tachycardia may have a history of dehydration or shock; examination evidence of dehydration, fever, or pallor; and a normal sized heart on chest x-ray. Infants with SVT often have a nonspecific history, an examination revealing rales and an enlarged liver, and possibly an enlarged heart on x-ray.
Defibrillation and Cardioversion
Ventricular fibrillation is rare in children but may be treated with defibrillation at 2 J/kg. If this attempt is unsuccessful, the energy is doubled to 4 J/kg. If two attempts at defibrillation at 4 J/kg are unsuccessful, epinephrine should be given and oxygenation and acid-base status should be reassessed. Cardioversion is used to treat unstable tachyarrhythmias at a dose of ¼ to ½ J/kg.
Use the largest paddles that still allow contact of the entire paddle with the chest wall. Electrode cream or paste is used to prevent burns. One paddle is placed on the right of the sternum at the second intercostal space, and the other is placed at the left midclavicular line at the level of the xiphoid.
NEONATAL RESUSCITATION
Most newborns do not require specific resuscitation after delivery, but about 6 percent of newborns require some form of life support in the delivery room. Emergency departments, therefore, must be prepared to provide neonatal resuscitation in the event of delivery in the emergency department.
1.The first step in neonatal resuscitation is to maintain body temperature. The infant should be dried and placed in a radiant warmer.
2.The airway should be cleared by suctioning the nose and mouth with a bulb syringe or a DeLee trap.
3.Next, a 5- to 10-s examination should assess heart rate, respiratory effort, color, and activity. If the infant is apneic or the heart rate is slow (less than 100 beats per minute), administer positive-pressure ventilation with bag-valve-mask and 100% oxygen. The rate should be 40 breaths per minute. In mildly depressed infants, a prompt improvement in heart rate and respiratory effort usually occurs.
4.If no improvement is noted after 30 s and the condition deteriorates, endotracheal intubation should be performed.
5.If the heart rate is still below 50 beats per minute after intubation and assisted ventilation, cardiac massage should be started at 120 compressions per minute. Compressions and ventilations should be in a 3:1 ratio.
6.If there is no improvement in heart rate following these efforts, drug therapy may be used. Most neonates respond to appropriate airway management; therefore, drug therapy is rarely needed. Vascular access may be obtained peripherally or via the umbilical vein. The most expedient procedure in the neonate is to place an umbilical catheter in the umbilical vein and advance to 10 to 12 cm.
7.Epinephrine 0.01 mg/kg of 1:10,000 solution may be used if the heart rate is still below 100 beats per minute after adequate ventilation.
8.Naloxone 0.1 mg/kg IV may be useful to reverse narcotic respiratory depression. Isoproterenol 0.05 to 0.1 µg/min may be infused if epinephrine fails to raise the heart rate.
9.Sodium bicarbonate 1 to 2 meq/kg may be given if there is a significant metabolic acidosis; this therapy should be guided by blood gas values.
Prevention of Meconium Aspiration
Aspiration of meconium-stained amniotic fluid is associated with high rates of morbidity and mortality. With proper perinatal management, it is almost entirely preventable. If meconium is noted at the time of delivery, the nose, mouth, and pharynx of the infant should be suctioned with a DeLee trap prior to delivery of the infant’s shoulders. Repeat suctioning of the airway should be performed with the infant under the radiant warmer prior to drying and stimulating the infant. This may be accomplished by visualizing the trachea with a laryngoscope and suctioning via an endotracheal tube. After suctioning, the infant should be dried and stimulated.
