The most frequent cause of cardiac arrest in pediatric patients is a
terminal result of respiratory failure or shock, not a primary cardiac
Developmental changes and immaturity of the respiratory system make
respiratory distress the most common reason for hospital admission in
the first year of life. Nasal flaring and grunting are unique features of
the respiratory examination in infants that indicate respiratory distress.
The normal respiratory rate in children changes over time; therefore, the
respiratory rate that would be of concern varies based on the age of the
Oxygen should be administered immediately in a child where respiratory
difficulty is suspected. Once the decision is made to intubate the patient,
the choices for pharmacotherapy of intubation vary based on the
cardiovascular stability of the patient, whether the stomach is empty or
full, and the underlying cause of the respiratory distress.
Hypovolemic shock is the most common type of shock seen in pediatric
patients. Septic shock, obstructive shock, and cardiogenic shock occur
in children but are less common. The initial treatment of all forms of
shock is the same. A pediatric patient can present with compensated or
decompensated shock. There are physiologic differences in the pediatric
patient’s response to hypovolemia, with hypotension being the last
physiologic change during decompensation.
Infants have low glycogen stores, so are at high risk for the development
of hypoglycemia when they have poor oral intake or during conditions of
stress. Because hypoglycemia may cause seizures and is linked to poor
neurologic outcome, all critically ill infants should have point-of-care
glucose testing on presentation. If identified, hypoglycemia must be
Due to the immature immune system in the infant, the incidence of
septic shock is the highest in the first year of life. Patients with
underlying medical conditions have a higher mortality rate than
previously healthy children who experience sepsis.
Due to physiologic changes during childhood, the definitions of sepsis and
systemic inflammatory response syndrome (SIRS) are different in
children and adults. Tachycardia and tachypnea, pivotal to the adult
definition of SIRS, are common presenting symptoms of many pediatric
disease processes and are not solely indicative of sepsis. Unlike adult
guidelines, temperature variation and leukocyte abnormalities are
included in the pediatric definitions. There are also specific definitions
Septic shock can be further defined by the patient’s response to fluid
resuscitation and catecholamine administration. These factors, as well
as physiologic differences in neonatal and pediatric cardiovascular
physiology compared with adults, affect not only the choice of therapy
but also drug dosing and monitoring.
Neonates with ductal-dependent congenital heart disease (CHD) may
not be diagnosed immediately after birth. These patients may present
with symptoms of being either in respiratory distress, in cardiogenic or
obstructive shock, or in a combination of both. It is essential to consider
CHD in any neonate who presents with these symptoms.
Traumatic brain injury (TBI) is the leading cause of mortality in children
and leads to significant morbidity among survivors. The anatomic
differences of the child’s brain render it more susceptible to certain
types of injuries after head trauma. Causes vary by age, with
nonaccidental trauma seen most commonly in the first year of life.
Quick assessment of the patient on presentation to emergency services
is needed for appropriate diagnosis, stabilization, and treatment.
Placement of a ventriculostomy will allow for measurement of
intracranial pressure (ICP) and drainage of cerebralspinal fluid. The
ability to measure ICP will assist in the evaluation of the efficacy of
treatments. Cerebral perfusion pressure (CPP) also must be monitored
closely in patients with TBI. Goal CPP values vary by age. Standard
therapies to reduce ICP include CSF drainage, medically induced
hypertension, and hyperosmolar therapy with mannitol or hypertonic
saline. When standard therapies fail, barbiturate coma, therapeutic
hypothermia, or decompressive craniectomy may be considered.
Treatment and/or prevention of early post-traumatic seizures has been
shown to improve outcomes, but long-term use of anticonvulsant
medications (greater than 7 days) has not been shown to improve
outcomes and is associated with adverse effects.
Much of pediatric practice is dedicated to assisting the child in making the transition
from the intrauterine environment through infancy, childhood, and adolescence to
adulthood. One of the greatest challenges in managing pediatric patients is
recognizing the numerous physiologic changes that take place during this time and
understanding how they affect assessment and management of the patient. The
definition and presentation of many disease states encountered in the critical care
setting, including respiratory depression, supraventricular tachycardia, hypotension,
and shock, vary based on the age of the patient as a result of these physiologic
variations. There are also newborn emergencies that are unique to the physiologic
transitions that occur in the first month of life.
Pediatric healthcare providers practicing in critical care settings such as the
emergency department or pediatric intensive care unit (PICU) must be adept at
incorporating these physiologic differences into medication selection, dosing, and
monitoring to optimize patient care.
The epidemiology of patients admitted to either the pediatric emergency
department or PICU differs from that typically seen in adult critical care settings.
an evaluation of 361 children presenting to an emergency department, the most
common medial reasons for admission were cardiocirculatory causes (32%),
neurologic conditions (26%), and respiratory causes (23%).
causes included hypovolemic, septic, cardiac, and anaphylactic shock. Neurologic
conditions consisted primarily of seizures, status epilepticus, and meningitis or
encephalitis. The most common respiratory cause for admission was respiratory
syncytial virus (RSV) bronchiolitis, followed by pneumonia, pleural effusions, and
croup. Eighteen percent (18%) of the patients were admitted after trauma. Diabetic
ketoacidosis accounted for 6% of admissions. Other diagnoses included
intoxications, near drowning, snake bites, and burns. Assessment of the most common
causes for PICU admission has provided similar results. In a review of 1,149
children admitted during a 2-year period to the PICU of a university-affiliated
children’s hospital, the majority (38%) were diagnosed with cardiovascular
diseases, followed by respiratory illnesses (28%), other medical causes (10%),
neurologic illness (8%), and trauma (8%). Another 7% were admitted for
2 When comparing admissions to pediatric intensive care from
1982, 1995, and 2005 to 2006, the most common medical diagnostic categories have
remained unchanged. However, fewer children were admitted after accidents, with
2 These changes can be explained by mandatory car seats
for children, administration of dexamethasone in the emergency department to
patients with croup and the conjugate Haemophilus influenza type b immunization.
During the same time period, the proportion of patients that died decreased from 11%
to 4.8%; however, the proportion of survivors with moderate or severe disability
increased significantly from 8.4% to 17.9%.
2 With the low rate of mortality in the
PICU, the focus of our research should investigate how to improve patient outcomes.
In marked contrast to pediatric cardiac arrest, adult cardiac arrest studies have
focused on the diagnosis and treatment of ventricular fibrillation (VF) in both
inpatient and out-of-hospital cardiac arrest. Studies showed that VF was the most
common initial dysrhythmia in adults with sudden death; in some reports, the
prevalence of VF was 60% to 85%. Cardiac arrest due to VF or pulseless ventricular
tachycardia as the initial cardiac rhythm occurs in only 5% to 15% of pediatric
patients in hospital and out-of hospital cardiac arrest.
In contrast to adults, cardiac
arrest in infants and children does not usually result from a primary cardiac cause;
more often it is the terminal result of progressive respiratory failure or shock.
Therefore, it is essential to recognize and treat pediatric patients admitted with
respiratory distress, pneumonia, and shock aggressively to prevent the development
of systemic hypoxemia, hypercapnia, and acidosis that may then progress to
bradycardia, hypotension, and eventually cardiorespiratory arrest.
resuscitation and what would the appropriate dose be?
Epinephrine is the drug of choice for the management of pediatric asystole.
Ventilation and chest compressions should be continued for C.W., and while one
responder is attempting IV access, another may administer the first dose of
epinephrine down the ETT using a higher dose of 0.5 mg (0.1 mg/kg prepared from
the 1:1,000 or 1 mg/mL concentration) to account for reduced absorption. If two
attempts at IV line placement are unsuccessful, an intraosseous (IO) catheter should
be inserted into the proximal tibia. Blood may be obtained through the IO needle to
perform a rapid glucose check and sent for further studies. After reassessment of the
airway, ventilation and chest compressions should be continued. Subsequent doses of
epinephrine can be administered every 3 to 5 minutes through the IO line, using the
appropriate IV/IO dose of 0.05 mg (0.01 mg/kg using the 1:10,000 or 0.1 mg/mL
Respiratory distress, related to problems at all levels of the respiratory tract from the
nose to the lungs, is a frequent occurrence in children.
of the signs of respiratory distress in an infant, go to
http://www.youtube.com/watch?v=42jJ18fkZ0Y.) The nose provides nearly half
the total airway resistance in children. Infants under 2 months are obligate nasal
breathers, and their nose is short, soft, and small with nearly circular nares. The
nares will double in size from birth to 6 months but they can easily be occluded from
edema, secretions, or external pressure. Simply clearing the nasal passageways with
saline and bulb suctioning can significantly improve an infant’s respiratory condition.
Other physiologic reasons for a high incidence of respiratory failure in infants and
children are small and collapsible airways, an unstable chest wall, inadequate
collateral ventilation for alveoli, poor control (tone) of the upper airway
(particularly during sleep), tendency for the respiratory muscles to fatigue, reactivity
of the pulmonary vascular bed (increased sensitivity of the vasculature, particularly
in young infants), an inefficient immune system, genetic disorders or syndromes, and
residual problems related to premature birth such as bronchopulmonary dysplasia.
saturation of 90% on 100% FIO2
via nasal cannula, nasal flaring and grunting, and both
the need for an emergency room visit in a 7-month-old previously healthy child?
The most common reason for admission to the hospital in the first year of life is
respiratory distress. This can be explained by the numerous physiologic differences
seen in an infant. Although all the conducting airways are present at birth and the
airway branching pattern is complete, the airways are small.
increase in size and length throughout childhood. Not only are the airways smaller in
an infant but supporting airway cartilage and elastic tissue are not developed until
school age. For these reasons, the child’s airways are susceptible to collapse and
may easily become obstructed as a result of laryngospasm, bronchospasm, and edema
or mucus accumulation. Normal airway resistance is the highest in infants because it
is inversely proportional to 1/radius
. Therefore, any airway narrowing from
bronchospasm, edema, or mucus accumulation will significantly increase the airway
resistance and increase the infant’s work of breathing. The cartilaginous ribs of the
infant and young child are twice as compliant as the bony ribs of the older child or
adult. During episodes of respiratory distress, the infant’s chest wall will retract
further than a patient with a bony ribcage. This will reduce the patient’s ability to
maintain functional residual capacity (FRC) or increase tidal volume, thus further
increasing the patient’s work of breathing.
The respiratory muscles consist of muscles of the upper airway, the lower airway,
and the diaphragm. They contribute to expansion of the lung and maintenance of
airway patency. Lack of development of the small airway muscles may render young
infants less responsive than older children to bronchodilator therapy. Lastly, the
intercostal muscles are not fully developed until school age, so they act primarily to
stabilize the chest wall during the first years of life. Because the intercostal muscles
have neither the leverage nor the strength to lift the rib cage in the young child, the
diaphragm is responsible for the generation of tidal volume. Therefore, anything that
impedes diaphragm movement, such as a large stomach bubble, abdominal
distension, or peritonitis, can result in respiratory failure in the young child.
CASE 106-2, QUESTION 2: What respiratory signs and symptoms are present in T.F. and how do they
define the patient’s respiratory status? What are potential causes of T.F.’s respiratory distress?
To assess a patient for respiratory distress, one should evaluate four areas:
respiratory rate and effort, work of breathing, quality and magnitude of breath sounds,
and the patient’s mental status. Normal respiratory rates vary with age (Table 106-1).
A respiratory rate greater than 60 breaths/minute is abnormal in a child of any age,
but most concerning in an older child. An abnormally slow or decreasing respiratory
rate may herald respiratory failure. Intercostal, subcostal, and supracostal retractions
increase with increasing respiratory distress. Although increased retractions are seen
in infants, they have decreased efficiency of respiratory muscle function during the
first years of life; therefore, the benefit in infants is reduced. Decreasing respiratory
rate and diminished retractions in a child with a history of distress may signal severe
fatigue. Nasal flaring is an effort to increase airway diameter and is often seen with
hypoxemia. T.F. demonstrates all of these physiologic signs of respiratory distress. In
addition to these findings, some infants will exhibit an expiratory grunting noise. This
noise is produced by the child’s involuntary effort to counter the loss of FRC by
closing their glottis on active exhalation. Grunting produces positive end-expiratory
pressure (PEEP) in an effort to prevent airway collapse. An expiratory grunt is
mechanistically similar to “pursed lip breathing” in adults with chronic dyspnea. An
expiratory grunt is classically seen in the presence of extensive alveolar pathology
and is considered a sign of serious disease.
Normal Respiratory Rates and Definition of Tachypnea for Children, by Age
There are numerous causes of respiratory distress in infants and children. Table
106-2 summarizes common respiratory noises in children and their site of origin
which may provide clues to the clinical cause. The most common causes of
respiratory failure in infants and children are infectious diseases, asthma,
malignancies, trauma (both accidental and nonaccidental), poisonings, foreign body
causes of respiratory distress in infants and young children, leading to an estimated
90,000 hospitalizations each year.
6 Although RSV can occur at any age, it is most
severe in children under 2 years of age such as T.F. Prematurity, as well as chronic
respiratory disease and congenital heart disease, increases the risk for severe RSV
bronchiolitis requiring hospitalization.
Oxygen should be administered immediately in any patient where respiratory
difficulty is suspected. Infants and children consume 2 to 3 times more oxygen per
kilogram of body weight than adults under normal conditions and even more when
they are ill or distressed. T.F. responded well to oxygen administered via nasal
cannula in the emergency department, but is now increasingly somnolent and has a
decreased respiratory rate along with decreased oxygen saturation values—all signs
of impending respiratory failure. The specific indications for intubation in infants and
Common Airway Noises, Site of Origin, and Clinical Causes in Children
Noise Definition Site of Origin
Wheeze A high-pitched, continuous
Intrathoracic airways Intermittent
Rattle This sound is the result of
Acute viral bronchitis Chronic sputum
Stridor This is predominately an
Snore The noise arises from an
obvious during inspiration, but
Snuffle/Snort These terms describe
Acute viral head cold Allergic rhinitis
For examples of some of these airway noises, go to the following web links:
Wheeze: http://www.youtube.com/watch?v=YG0-ukhU1xE&feature=related
Rattle/rhonchi: http://www.youtube.com/watch?v=QPBZOohj2a0&feature=related
Toddler: http://www.youtube.com/watch?v=Zkau4yHsLLM&feature=related
Infant: http://www.youtube.com/watch?v=73zUjcCzgqA&NR=1
Grunt: http://www.youtube.com/watch?v=aptwttJ6y_4
Acute respiratory failure (Pao2 <50 mm Hg in patient with FIO2 >0.5 and Paco2 >55
Need to control oxygen delivery, with institution of PEEP or to provide accurate
delivery of FIO2 greater than 0.5
Need to control ventilation to decrease work of breathing, control Paco2
administer neuromuscular blocking agents
Inadequate chest wall function, as in patients with neuromuscular disorders such as
Guillain–Barré syndrome, spinal muscular atrophy, or muscular dystrophy
Protection of the airway of a patient whose protective reflexes are absent, such as
Based on the diagnosis of acute respiratory failure and the need to control oxygen
delivery, T.F. should be intubated and placed on mechanical ventilation.
MEDICATIONS FOR INTUBATION AND
CASE 106-2, QUESTION 4: What pharmacologic agents are recommended when intubating a pediatric
patient? Develop a plan for the medications to be used during intubation of T.F.
After the decision is made to proceed with intubation, the next decision needs to
be whether pharmacologic agents are appropriate. Most pediatric patients require
sedation before laryngoscopy and intubation. The goal is to depress the infant or
child’s level of consciousness sufficiently to produce appropriate conditions for
intubation. Pharmacologic therapy is used to produce adequate sedation, analgesia,
and amnesia plus a blunting of the physiologic response to airway manipulation.
Intubation in the awake state can elicit protective reflexes that trigger tachycardia,
bradycardia, and elevation of blood pressure, increased intracranial pressure,
intraocular pressure, cough, and bronchospasm. Pharmacologic control promotes a
smoother intubation with less physiologic stress for the patient who often is already
in a compromised state. Ideally, this should be accomplished while producing
minimal hemodynamic compromise.
There are many factors to be considered when choosing agents for intubation: the
onset of action of the agent, the patient’s hemodynamic status, the need to prevent
increased intraocular or intracranial pressure that may be caused with intubation, and
whether the stomach is full or empty. A wide variety of medications may be used for
pediatric sedation, each with its own risk and benefits (Table 106-3).
agents that act rapidly and are eliminated quickly are ideal. Often drug choices are
made based on the clinician’s experience with a particular drug and the immediate
availability of the drug. Most importantly, the drug regimen chosen must be based on
the patient’s physiologic state. Agents with adverse effects that would exacerbate any
underlying medical conditions must be avoided. Narcotics used in combination with
anxiolytics are used commonly. To produce optimal conditions for intubation, T.F.
could be given 12 mcg of fentanyl (1 mcg/kg) and 1.2 mg of midazolam (0.1 mg/kg)
IV before the procedure to provide sedation and analgesia. Both agents are relatively
short-acting and reversible if difficulties arise with ETT placement.
Patients with inadequate relaxation despite adequate sedation may require
neuromuscular blockade, although these agents are not without risk. In a patient with
a partial airway obstruction, neuromuscular blockade may worsen pharyngeal
collapse, potentially resulting in complete airway obstruction. Therefore,
neuromuscular blocking agents should only be used if the clinician is absolutely
certain that adequate ventilation can be provided or that the patient can be intubated.
younger than 5 years have a high vagal tone; therefore, they are more likely to exhibit
bradycardia when intubated. Instrumentation of the airway can directly stimulate
vagal receptors and induce bradycardia. In these patients, it is prudent to administer
atropine 0.02 mg/kg before intubation to blunt the autonomic response. Lidocaine (1–
1.5 mg/kg/dose with a maximum dose of 100 mg) may be administered intravenously
to blunt the airway protective reflexes elicited by instrumentation. This may be
particularly useful in a patient with elevated intracranial pressure (ICP).
In the asthmatic patient, drugs that release histamine (e.g., morphine, atracurium, or
thiopental) and have the potential to produce laryngospasm or bronchospasm should
be avoided. The beneficial bronchodilatory side effects of ketamine, however, make
it a useful choice in these patients. In a child with increased ICP, the choice of
pharmacologic agent depends on the hemodynamic status of the patient. Thiopental or
pentobarbital is an excellent choice in the hemodynamically stable patient whereas
etomidate is preferred if the patient is unstable or hypovolemia is suspected.
Etomidate should not be used routinely in pediatric patients because a single dose
administered for intubation has the potential to produce adrenal inhibition.
children and adults with septic shock, etomidate administration is associated with a
In all cases of intubation, preoxygenation is carried out to increase the available
oxygen in the lungs during the procedure, thus giving the practitioner some buffer time
to intubate the patient. However, in patients with an elevated ICP or pulmonary
vascular hypertension, hyperventilation is recommended to also produce hypocarbia.
A summary of specific patient conditions and recommended agents for intubation can
be found in Table 106-4. In an infant or child with a full stomach, the risk of
aspiration of gastric contents is high. Rapid sequence intubation (RSI) is used when
there is an aspiration risk, such as the child with a full stomach, and there is no
concern of a difficult intubation.
11 The goal of RSI is to gain airway control with an
ETT as quickly as possible to prevent aspiration. The patient is preoxygenated via
face mask and bag-mask ventilation cannot be used because it causes gastric
distension. Once all necessary intubation equipment is ready, rapidly acting sedative,
analgesic, and paralytic medications are administered simultaneously. Cricoid
pressure must be maintained until the ETT is in place and confirmed to provide
adequate protection from aspiration. An end-tidal CO2 detector should be attached to
the ETT after intubation to confirm proper placement in the trachea. Colorimetric
end-tidal CO2 devices change color from purple to yellow to confirm the presence of
exhaled CO2 and tracheal placement.
Endotracheal intubation and mechanical ventilation can be painful, frightening, and
anxiety provoking, especially in a young child. To improve patient comfort, relieve
anxiety, and lessen the work of breathing, anxiolytics, sedatives, and analgesics are
frequently administered once the patient is intubated and mechanically ventilated.
Maintenance of adequate sedation is essential. Selection of appropriate agents is
based on the physiology of the patient. Guidelines for the use of continuous infusions
are outlined in Table 106-3. In the paralyzed patient, neuromuscular blockade neither
alters consciousness nor provides analgesia; therefore, adequate sedation and
analgesia are essential. Providing effective analgesia and sedation to the pediatric
patient depends on accurate ongoing efforts to assess the intensity of the patient’s
pain or anxiety. The assessment of pain and anxiety in infants and critically ill
children who are unable to communicate relies heavily on physiologic and
behavioral responses. A number of pain and sedation tools have been developed and
validated specifically for use in children.
12 No single standard measure gives a
complete qualitative or quantitative measure. Selection of an appropriate tool is
based on the child’s age, underlying medical condition, and cognition level. It is
essential that these tools are utilized to evaluate the adequacy of the ICU sedation.
Policies and procedures need to be in place for the appropriate selection and use of
each tool, in addition to training of all healthcare professionals to appropriately use
each tool. The goal is to use the minimum amount of sedation needed to adequately
sedate the intubated child, while minimizing adverse effects.
Pharmacologic Agents Used for Pediatric Intubation and Continuous Sedation
Drug Route Dose Onset Duration Benefits
Pentobarbital IV 2 mg/kg/dose (max:
IM/PO/PR 2–6 mg/kg/dose IM: 10–15
Dexmedetomidine IV 0.5–1 mg/kg/dose
30 minutes 4 hours Minimal to no
Succinylcholine IV 1 mg/kg/dose 30–60
Rocuronium IV/IM 0.6–1 mg/kg/dose 60–75
Management Examples of Specific Patient Cases
Fullstomach Prevent passive regurgitation and
aspiration after airway protective
Bronchospasm Eliminate or treat stimuli that would
induce or increase bronchospasm
Ketamine, vecuronium, lidocaine,
Increased intracranial pressure No increase in heart rate or blood
Thiopental/pentobarbital, etomidate,
vecuronium, rocuronium, lidocaine
Pulmonary vascular hypertension Avoid decreased pulmonary blood
Midazolam, fentanyl, vecuronium
Hypokalemia or depressed cardiac
Maintain blood pressure without
placement of IV access were as follows:
What type of shock might M.M. be experiencing?
Shock may be classified as hypovolemic, distributive, cardiogenic, or obstructive.
Based on his presentation, M.M. is most likely presenting with hypovolemic shock,
the most frequent type of shock seen in pediatric patients. Hypovolemic shock occurs
when circulating intravascular volume decreases to a point at which adequate tissue
perfusion can no longer be maintained. Hypovolemia causes a decrease in preload
and adversely affects cardiac output. Initially, hypovolemia activates peripheral and
central baroreceptors that cause catecholamine-mediated vasoconstriction and
tachycardia. This initial response can maintain adequate circulation and blood
pressure even after acute loss of as much as 15% of the circulating blood volume.
Shock results from inadequate blood flow and oxygen delivery to meet the metabolic
3 Shock will progress from an initial compensated state to
decompensated state. Typical signs of compensated shock include tachycardia, cool
and pale distal extremities, prolonged (>2 seconds) capillary refill, weak peripheral
pulses compared with central pulses, and normal systolic blood pressure. As shock
progresses, the patient will exhaust his ability to compensate. The patient will exhibit
signs of inadequate end-organ perfusion, including depressed mental status,
decreased urine output, metabolic acidosis, tachypnea, weak central pulses, and
mottling of extremities. M.M. shows evidence of having progressed to this later
stage, with lethargy and decreased urine output.
CASE 106-3, QUESTION 2: How should M.M. be initially managed and monitored?
All patients presenting with shock should be placed on high-flow oxygen while
their initial evaluation is being performed. Initial volume resuscitation in all forms of
shock is the same. It is recommended to push isotonic crystalloid fluid (normal saline
or lactated Ringer’s solution) in 20 mL/kg boluses administered over 5-10 minutes.
Immediately reassess the patient for signs of improved perfusion, using clinical
criteria such as reduction in heart rate, improvement of blood pressure, capillary
refill, quality of pulses, and mental status. If the clinical signs of shock persist,
another 20 mL/kg of isotonic fluid should be administered, reaching, if necessary, at
least 60 mL/kg within the first 15 to 30 minutes of treatment.
points of fluid resuscitation in patients with shock are capillary refill less than 2
seconds, normal pulses with no difference between central and peripheral pulses,
warm limbs, urine output greater than 1 mL/kg/hour, normal mental status, decreased
lactate as measured on arterial blood gases (ABG), and increased base deficit.
Children normally have a lower blood pressure than adults and are better able to
preserve adequate blood pressure by vasoconstriction and increasing heart rate;
therefore, blood pressure by itself is not a reliable end point for evaluating the
adequacy of resuscitation. Hypotension is the last thing to occur in pediatric shock
states. The definition of hypotension, defined as the 5% for systolic blood pressure
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