Pediatric emergency medicine trisk 51
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FIGURE 9.5 Oropharyngeal airway: flange (A ), bite block (B ), stent (C ), and gas exchange
or suction conduit (D ).
FIGURE 9.6 Nasopharyngeal airways in a variety of sizes.
BREATHING
Evaluation
Breathing is assessed through observation of chest wall movement and
auscultation. Gas exchange is confirmed by auscultation and monitoring of
ETCO2 and pulse oximetry.
MANAGEMENT
Spontaneous Ventilation
Supplemental oxygen is administered to the spontaneously breathing ill patient. If
the patient is not breathing spontaneously, positive pressure ventilation (PPV) is
required. Though the optimal concentration is not known, it is reasonable to
provide 100% oxygen during CPR. Hyperoxia is a mediator of postresuscitation
injury, thus titration of FiO2 to the minimum concentration to achieve saturation
of at least 94% is recommended.
Oxygen Delivery Devices
A variety of oxygen delivery devices are available for use in patients who have
patent airways. The percent oxygen delivered depends on the child’s size and
minute ventilation.
Nasal Cannulas
One hundred percent humidified oxygen is delivered to the nares at a flow of 4 to
6 L/min. Due to entrainment of room air, the final oxygen delivery is low, usually
30% to 40%.
High-Flow Nasal Cannulas
High-flow nasal cannula (HFNC) delivers humidified and warmed oxygen/gas at
flow rates up to 12 L/min in infants and 30 L/min in children. HFNC supports
respiration though noninvasive continuous positive airway pressure (CPAP),
improved airway mechanics, reduction of metabolic expenditure, and improved
clearance of secretions. It has been used as an alternative to CPAP devices,
especially for infants with bronchiolitis. The initiation and management of HFNC
requires close monitoring by a team skilled in its use.
Oxygen Masks
There are several types of oxygen masks that offer a wide range of inspired
oxygen concentrations.
Simple masks. The simple face mask delivers a moderate FiO2 that varies from
35% to 60%.
Partial rebreathing masks. Partial rebreathing masks allow reliable delivery of an
FiO2 of 50% to 60%. When the flow in the reservoir bag is greater than the
patient’s minute ventilation and the oxygen is adjusted so the bag does not
collapse during inhalation, there is negligible CO2 rebreathing allowing for more
reliable oxygen delivery.
Nonrebreathing masks. These masks have nonrebreathing valves incorporated
into the face mask and the reservoir bag and reliably provide oxygen
concentrations up to 95% with high flow rates of 10 to 15 L/min.
Continuous Positive Airway Pressure Devices
CPAP provides positive pressure to stent open the child’s airways leading to
improved ventilation and oxygenation. CPAP can be applied with large nasal
prongs, a nasal mask which covers just the nose of the patient, or a face mask
which covers the mouth and nose.
Assisted Ventilation
Basic Life Support (BLS) rescue breathing rate in infants and children with
isolated respiratory arrest is 12 to 20 breaths/min, with higher rates for infants and
younger children. Newly born infants may need a rate of 40 to 60 breaths/min.
For children and infants who require CPR, the recommended respiratory rate is 8
to 10 breaths/min. Ventilations are asynchronous with chest compressions when
an advanced airway is in place. When an advanced airway is not in place,
ventilations are coordinated with chest compressions with a rate of 15
compressions to 2 ventilations for two providers and 30 compressions to 2
ventilations for one provider (100 to 120 compressions/min). With all ventilation
techniques, the force and volume needed to just see chest rise is recommended.
Overventilation is a common error in resuscitation; the AHA 2015 Update
emphasizes a ventilation rate of less than 12 and a ventilation volume that causes
no more than minimal chest wall rise during CPR.
Because of risk of infection transmission, mouth-to-mouth resuscitation is no
longer recommended. Instead, rescue breathing is done with a pocket mask.
Placement of the mask over the mouth alone, over the mouth and nose, or over a
tracheostomy site depends on the patient and the equipment available.
Expired Air Techniques
BVM ventilation is an essential skill for all emergency medicine clinicians and
provides a rapid means to provide oxygenation and ventilation for children with
respiratory and/or circulatory failure.
Masks
The properly fit mask covers the tip of the chin, the mouth, and the nose, allowing
for a tight seal against the skin. Masks with a pneumatic cuff design allow for the
easiest and most efficient fit that avoids air leaks. When enough personnel are
available, a two-person technique may improve oxygen delivery and ventilation.
One person uses both hands to correctly position the mask on the face, creating a
good seal, while the other squeezes the bag, paying attention to ensure
appropriate chest rise and ventilation.
FIGURE 9.7 Self-inflating hand-powered resuscitator: compressible unit (A ), oxygen source
(B ), oxygen reservoir (C ), one-way valve assembly (D ), and mask with transparent body (E ).
Hand-Squeezed, Self-Inflating Resuscitators
