This supplemental training module was developed by the Johns Hopkins Children Center: HOPE Program (Hopkins Outreach Pediatric Education) staff and reviewed by the state Pediatric Emergency Medical Advisory Group (PEMAG). A Master Copy is located in the MIEMSS EMSC program office. Any changes to the contents of this CD and PowerPoint presentation must be submitted to PEMAG for review. This module was designed to augment the primary and continuing education of BLS and ALS providers in Maryland and may be used in conjunction with other training programs.For more information please contact the Maryland EMSC Office at (410)706-1758.
Instructor note: 1. Refer to the Croup Protocol in the Maryland Medical Protocol, 1/2002, for specific EMS management. 2. It is recommended that a variety of types of oxygen delivery systems and nebulizers be available for the student to see. 3. Instructor qualifications: this pediatric continuing education program may be taught by those individuals recognized by their jurisdictional EMS Operational Program as an ALS approved instructor, (COMAR 30.04.05)
The term “croup” describes a viral infection of the vocal cords (larynx). The inflammation of the larynx leads to the characteristic “croupy” sound, particularly when the child is crying or agitated. Most children with viral croup are between the ages of three months and four years of age. The most severe symptoms are seen in children under the age of three. The incidence of croup is more common in males and during the cold/flu season of the year. Most croup due to viruses is mild and “self limiting”, although occasionally viral croup can be severe and even life threatening. Croup has a typical duration of five to six days.
The viruses most commonly involved are parainfluenza virus (accounting for about 75% of the cases), adenovirus, respiratory syncytial virus (RSV), influenza, and measles. Bacterial super infection is uncommon, but if it occurs it causes the more serious entity of bacterial tracheitis.
The main reason children are prone and have more severe signs and symptoms with airway edema is the fact that the airway is cone shaped and the narrowest point is at the level of the cricoid ring. Children also have more anterior vocal cords and the tongue is larger in proportion to the mouth.
These diagrams illustrate the differences between the pediatric and adult airway structures.
In addition the lower airways are smaller and more collapsible. Children are dependent on the use of their diaphragm for breathing because they have poorly developed intercostal and accessory muscles.
Croup is characterized by a loud barking cough, inspiratory stridor, and respiratory distress. At first, a child may have an upper respiratory infection for several days before the onset of cough. As the upper airway progressively becomes more inflamed and swollen, the child may become hoarse, and work of breathing increases with retractions, nasal flaring, and head-bobbing. Typically with severe croup there may be high-pitched noise “stridor” during inspiration with signs/symptoms of respiratory failure.
Additional manifestations of the ongoing viral infection may include ear infection and pneumonia. These can occur before, during, and after the symptoms of croup begin.
The neck x-ray on the left shows a normal upper airway. Notice the arrows indicating the squared appearance of the Cricoid area. This finding is called the “shoulders” of the airway. The neck x-ray on the right shows an x-ray consistent with Croup. Notice the arrows indicating the narrowed upper airway at the level of the vocal cords. This x-ray finding is called the “steeple sign.” Most Croup diagnoses are made from clinical signs and symptoms, a neck x-ray may be helpful to rule-out FBAO, or epiglotitis in children over 3 years of age.
Croup is one of many causes of upper airway obstruction in children. Non-infectious causes of upper airway include vascular ring, tracheamalacia, and foreign body aspiration. A vascular ring is a congenital defect where one of more of the large blood vessels in the chest or neck are wrapped around the trachea putting pressure on the trachea until it bends or kinks causing airway obstruction. Tracheamalacia is a softening of the tracheal wall, in which the cartilage is no longer strong enough to support air flow, causing stridor and possible airway obstruction. Tracheamalacia is usually caused by intubation and mechanical ventilation in the neonatal period. Children, especially toddlers are prone to foreign body aspiration. Typical foreign bodies include small toys, coins, cylindrical foods, and latex balloons. Infectious causes of upper airway obstruction include croup, epiglottitis and pharyngeal abscess. Epiglottitis a bacterial infection of the epiglottis.
The major diagnostic criteria for croup versus epiglottitis is the age, onset of illness, and clinical presentation. Epiglottitis usually affects children over the age of five and is associated with fever, drooling, inspiratory stridor, and a rapid onset. Drooling typically is caused when the child is not being able to swallow saliva due to the ballooning of the epiglottis into the pharynx.
If epiglottitis is suspected, do not treat the patient as if they have croup. In this case provide high flow oxygen, maintain a calm environment, and avoid manipulation of the upper airway. The hospital should be notified so that an ENT physician and anesthesiology can be standing by in case advanced airway management is needed, such as an emergent tracheostomy or a surgical cricothyroidotomy.
There are some general treatment principles that apply to treating any pediatric patient. First, allow children to assume their own position of comfort. The best position for a child in respiratory distress is a semi-fowlers position, which promotes diaphragm expansion. Second, allow the parent to remain with the child when feasible to provide emotional support. A child may be comforted by a favorite toy from home as well.
Third, it is important to get down to the child’s eye level and use age appropriate words. A fourth strategy is to give them choices if you are able, which allows them to have some control over the situation. For example, ask them to select which arm to have a blood pressure reading taken. If the child is stable, allow them to set the pace of the procedure. For example, some children like to count 1, 2, 3 before a needle stick.
Fifth, foster trust by always telling children the truth. The prehospital provider is the first medical professional the child encounters. If trust is broken in the beginning it is very difficult to regain trust later in the child’s illness. Finally, be aware of the capabilities of your local ED and location of the pediatric referral centers.
Oxygen administration in children can be challenging. Infants, for example do like to have anything, like an oxygen mask, on their face. If a mask is needed, have parent hold mask away from patient’s face without placing it over the child’s head. Another alternative is to use just the oxygen tubing set at 10 liters per minute and blow the oxygen past the patient’s nose or mouth area in the least obtrusive manner. The child may be more cooperative if one end of the tubing may be placed the inside of a paper cup with stickers on the inside. The tubing may also be taped to the cervical collar if the patient is in a spine immobilization device. Finally, it may be helpful to use a commercially designed teddy bear with a built in oxygen port. These devices deliver both oxygen and nebulized medications.
Select a priority based on the child’s presentation. Children in respiratory failure are a priority 1.
Children with significant respiratory distress are a Priority 2.
Start by assessing the patient. Airway patency may be assessed by rise and fall of the chest, presence of breath sounds, and good skin color. Stridor and head bobbing are classic signs of an upper airway obstruction. Signs and symptoms of increased respiratory effort include nasal flaring, retractions, grunting, and in the late stages of respiratory distress paradoxical breathing.
Pediatric respiratory failure can looked at on a continuum. Mild respiratory distress can be managed with good positioning and administration of supplemental oxygen. Children in the middle column with signs and symptoms of moderate respiratory distress must be treated by an ALS unit and may required inhaled medications. Patients in the right hand column need immediate life-saving interventions, including bag-valve mask ventilations to prevent respiratory arrest.
The first strategy for a child with a respiratory illness is usually an inhalation therapy. Starting an IV may only upset the child and increase the amount of respiratory distress. If IV attempts increase respiratory distress, they should be withheld unless the patient is in pre-arrest. In fact, over 75% of children seen in the Emergency Department with croup, do not receive an IV or IV medications.
Many children with croup will respond to nebulized saline. The humidified oxygen will decrease laryngeal swelling and improve the child’s respiratory effort. Therefore, the first line treatment in nebulized saline. Place 3 cc of 0.9% NaCl into a standard nebulizer and set the oxygen at 6 – 8 lpm. If the child responds well, a second saline neb may be administered. If there is no improvement, contact a medical control physician to administer inhaled epinephrine. There is some confusion about whether the protocol requires medical consultation for administration of nebulized saline. Each jurisdictional medical director must decide if they will consider this a protocol violation. It is essential that any child who receives nebulized epinephrine to be transported to the hospital. Rebound edema may occur as late as six hours after a nebulized treatment. Therefore, it may be prudent to begin transport prior to initiating the epinephrine treatment.
The dose of the standard form of Epinephrine Injection 1:1,000 (1mg/ml) is 0.5 ml/kg/dose. The maximum dose for children under 4 years of age is 2.5 ml/dose. For children over 4 years of age the maximum dose is 5.0 ml/dose. Each dose must be diluted to at least 3 cc of total volume, using 0.9% NaCl as the diluent. To simplify dosing, the prehospital protocol is 2.5 mg diluted with normal saline to a total volume of 3 ml. Side effects of nebulized epinephrine include tachycardia and increased blood pressure.
Epinephrine is an alpha-adrenergic receptor agonist that causes local vasoconstriction in the large airways. This vasoconstriction can temporarily reduce airway edema and obstruction, especially is spasmodic croup. Hospitals have used Racemic Epinephrine (Vaponefrin) for many years to treat patients with inspiratory stridor. Racemic Epinephrine is a mixture of both the active Levorotatory (L) and the Dextrorotatory (D) forms of Epinephrine. The standard injectable form (1:1,000) is a more potent solution of exclusively the active L-Epinephrine form. This preparation is most commonly used by EMS systems, where there is no access to refrigeration for opened vials Racemic Epinephrine. In the appropriate dosage, using the injectable form of Epinephrine has been shown to be as safe and effective as the racemic solution
If the child is in impending respiratory failure, then administration of 0.01 mg/kg of Epinephrine 1:1,000 SC is recommended. The maximum dose of SC epinephrine is 0.3 mg. Most pediatric respiratory emergencies can be managed with bag-valve mask ventilation. Children are more easily “bagged” than adult patients, and may not require intubation once they have received inhalation therapy or other medications to treat the underlying problem. Prehospital providers must not hesitate to initiate bag-valve mask ventilations, even in conscious children. There are no reports in the literature of complications from face mask ventilation in children, but we do know that a child can suffer serious effects if they are not adequately oxygenated and ventilated. If the child has concurrent wheezing an albuterol nebulization would also be recommended. Epinephrine and albuterol are compatible and may be administered together in the same nebulizer. It is important to remember that inhalation therapy must be continued if the patient is receiving bag-valve mask ventilations or is intubated. A 15 to 22 mm adapter may be used to attach a tradition nebulizer to the mask or endotracheal tube or a commercially designed nebulizer for intubated patients may be used. The adapted set-up is illustrated below. It is essential to place a small hole in the corrugated tubing of the nebulizer to facilitate exhalation through the closed system.
There are commercially available BVMs available that will accept a multi-dose inhaler. These can be bagged using the facemask or attached to an ETT.
Commercially available nebulizer treatments will also fit a BVM and can be bagged with a facemask or ETT. The arrow on the right shows a 15mm to 22mm adapter that is needed to connect the nebulizer to and ETT.
The criteria for assisting ventilations includes the following: inadequate respiratory rate including < 20 for infants, < 16 for children, and < 12 for adolescents. The most common cause of bradycardia in children is hypoxemia.
Another criteria for initiating bag-valve mask ventilations is inadequate respiratory effort as evidenced by absent or diminished breath sounds, paradoxical breathing, and cyanosis on 100% oxygen by non-rebreather mask. Hyperventilation is recommended for head injured patients with a glasgow coma score of < 8.
Routine cricoid pressure in children with an undocumented or recent fast (less than four hours) will help to decrease the risk of vomiting and aspiration. Placement of a gastric tube for decompression may also facilitate improved bag-valve mask ventilation. If pressure is placed on the child eyes it may stimulate the vagus nerve and cause bradycardia.
The key to bagging a child is the fit of the mask. When a mask is too large, providers will have part of the mask resting over the child’s eyes or under the soft tissues of the child’s chin. If pressure is placed on the child eyes it may stimulate the vagus nerve and cause bradycardia. Pressure under the soft tissues of the chin may cause the child’s tongue to obstruct the upper airway. A chart with the appropriate mask sizes is shown below.
Use of an airway adjunct such as an oropharyngeal or nasopharymgeal airway is also recommended. Caution must be used when inserting a nasopharyngeal airway into an infant since the base of the skull, the cribiform plate, has not completely hardened. It is also important to select an appropriate size bag. Neonatal bags are used in infants under three months of age. A pediatric bag is used in children who are less than 30kg (65lbs). An adult bag is used for larger children. If you do not get a chest rise when you completely deflate the bag then you want to move to a larger bag. A child cannot be ventilated with a bag that is too small, but they can be ventilated with a bag that is too large by adjusting the tidal volume that is delivered into the child’s lungs. Neonatal or pediatric bags may have a pressure pop-off valve. If the amount of pressure needed to deliver air into the patient’s lungs exceeds the level of the valve (usually 40 cm of H20) then the extra pressure will be released into the atmosphere. The pop-off valve on neonatal or pediatric bag should be disable during resuscitation. During resuscitation it is essential to deliver air to the patient’s lungs regardless of the amount of pressure that is required. Patients with congestive heart failure or near drowning, for example, may require very high pressures to deliver an adequate amount of air into their lungs.
The technique for bag-valve mask ventilations in children is essential to a good outcome. First, a good seal must be achieved either with two person technique or the E-C clamp method illustrated below. Use the squeeze-release-release method of bagging by ventilating once, giving two seconds for exhalation, then repeating the cycle.
Two provider technique also allows closer observation of the patient response, including chest rise and fall, presence of breath sounds, and improvement in skin color.
Assist ventilations at the following rates: infant/toddler 30-40 breath per minute (BPM), child 20-30 BPM, and adolescent 12-20 BPM. If you are bagging an infant or young child at the age appropriate rate and they are still hypoxic try the following strategies. First, slow down the rate a bit and keep the bag inflated a little longer on inspiration. This technique is called an end-inspiratory hold and will allow more time for oxygenation. The second strategy is to increase the respiratory rate, as high as 60 BPM for infants. Some children will respond better to the second strategy.
If bag-valve mask ventilations are effective there should be good rise and fall of the chest, bilateral breath sounds, and an improvement in skin color.
If bag-valve mask ventilations are ineffective assess for the following complications. First verify the size and seal of the mask. Ensure that the patient is properly positioned in the “sniffing position”. Check the oxygen source to ensure that the tank is full and operational.
Neonatal or pediatric bags may have a pressure pop-off valve. If the amount of pressure needed to deliver air into the patient’s lungs exceeds the level of the valve (usually 40 cm of H20) then the extra pressure will be released into the atmosphere. The pop-off valve on neonatal or pediatric bag should be disable during resuscitation. During resuscitation it is essential to deliver air to the patient’s lungs regardless of the amount of pressure that is required. If you do not get a chest rise when you completely deflate the bag then you want to move to a larger bag. A child cannot be ventilated with a bag that is too small, but they can be ventilated with a bag that is too large by adjusting the tidal volume that is delivered into the child’s lungs. Finally, assess the child for any change in condition such as a pneumothorax or absence of air movement secondary to severe bronchospasm. Finally, assess the child for gastric distension. Gastric distension with bag-valve mask ventilation is very common in children. It may be relieved by inserting a gastric tube for decompression. Remember if the tube is a #10 Fr or smaller tube, a syringe must be attached and the stomach manually decompressed. Attaching a small gastric tube directly to suction may result in a collapsed tube.
Which of these vital signs concern you? What prehospital interventions would be appropriate for this patient?
The priority for any child with upper airway obstruction is to reduce stimulation so that the child does not cry and increase work of breathing. The first intervention for Croup is humidified oxygen which may reduce the swelling in the upper airway. The majority of children with Croup will not need an IV, however if the child develops signs and symptoms of respiratory failure an IV will be needed for emergency medications.
The ED administered 2 epinephrine nebulization treatments since the patient was still in significant distress with the humidified oxygen. There is a research study published by Children’s Nation Medical Center, showing that the IV form of epinephrine is just as effective as Racemic epinephrine, but many hospitals continue to use Racemic epinephrine.
Since the definitive treatment for the upper airway swelling is steroids, the transport team wanted the steroids given as soon as possible. Remember, the steroids will not take effect for several hours, so respiratory support as well as epinephrine nebulization treatments may be necessary until the steroids begin to work. Since the patient was having persistent respiratory distress despite treatment, the transport team felt that an IV was essential in case emergency medications were required.
A falling respiratory rate with poor skin color are classic signs of respiratory failure in children. Since the infant has become fatigued after trying to breathe through a narrowed upper airway, the child will require intubation and mechanical ventilation until the steroids begin to decrease the swelling in the vocal cords. Children with Croup, rarely require intubation, but a child with a significant medical condition may have a harder time compensating for increased work of breathing.
Right mainstem intubation is common in children since their upper airway is shorter. While chest rise, the presence of breath sounds, good skin color and a positive end tidal CO2 level may verify placement in the trachea, only a chest x-ray will show if the tip of the ETT is at the appropriate level. This is essential in infants and toddlers since there is such little margin for error with tube placement. If the ETT is too deep it may migrate into the right mainstem during transport. If the ETT is too shallow it may migrate into the pharynx during transport.
This is a good example of how well patients can do once they respond to the steroids. However, if the child did not receive respiratory support during the acute period the child may have sustained a cardiac arrest or brain damage from the untreated respiratory failure.
Maryland Pre-hospital Protocol for Croup Maryland EMSC Program
Care for Children with Croup Developed by Hopkins Outreach for Pediatric Education Written by Elizabeth Berg, RN, BSN, EMT-B Reviewed by Maryland PEMAG 7/2001