INTRODUCTION
A “critically ill child” is a child who is in a clinical state which may result in respiratory or cardiac arrest or severe neurological complications if not recognized and treated promptly. Many diseases can lead to this “critically ill state”. Whether a child presents with a primary cardiovascular, respiratory, neurological, infectious or metabolic disorder, the goal should be early recognition of respiratory and circulatory insufficiency. Timely intervention in seriously ill or injured children is the key to preventing progression towards cardiac arrest and to saving lives.
An experienced clinician finds it easy to recognize a critically ill child. It is essential for the clinician to assess and classify the degree of illness. It is also important to identify a child with physiological derangement in its early stages when signs are subtle. The “golden hour” concept applies to all children with illnesses presenting as emergencies. Early recognition of a “critically ill child” requires a systematic and rapid clinical assessment, with background knowledge of age appropriate physical signs and level of development. The process of examining a child is known as Rapid Cardiopulmonary Assessment. With practice, it should take the clinician about 30 seconds to complete this assessment.
APPROACH TO PEDIATRIC ASSESSMENT
To evaluate and treat a seriously ill or injured child; the ‘assess-categorize-decide-act’ model should be used. This process is iterative. If at any point you identify a life-threatening problem, start life-saving interventions immediately and get help by activating the emergency response system that is in place in your own setting (ERS).
The child should be assessed using a systemic approach. There are four parts to pediatric assessment:
- General assessment: A rapid visual and auditory assessment of the child's overall appearance, work of breathing and circulatory status should be completed within the first few seconds of patient encounter.
- Primary assessment: A rapid, hands on ABCDE approach to evaluate cardiopulmonary and neurologic function; this step includes assessment of vital signs and pulse oximetry.
- Secondary assessment: A focused medical history using the SAMPLE mnemonic and a thorough head-to-toe physical examination.
- Tertiary assessment: Laboratory, radiographic and other advanced tests that help to establish the child's physiologic condition and diagnosis.
GENERAL ASSESSMENT
The general assessment using the pediatric assessment triangle represents the initial visual and auditory assessment of the seriously injured child within the first few seconds of patient contact.
Determine if Life-Threatening
Based on the initial crucial information, one should determine if the condition is lifethreatening or not life-threatening. In case of life-threatening condition, life-saving interventions should be promptly started and the ERS should be activated.
A very simple and quick way of primary assessment of overall illness and injury severity is by the mnemonic ABCDE:
- Appearance of the child/Airway
- Breathing
- Circulation
- Disability
- Exposure.
APPEARANCE OF THE CHILD
Appearance basically denotes the neurological status. It is determined by the oxygen and blood supply to the brain, which is dependent on the cardiopulmonary status and 3the structural integrity of the brain. The parameters assessed in appearance are alertness, distractibility or consolability, response to stimuli, eye contact, speech or cry, motor activity and color of the skin. In addition, seizures, abnormal posture, muscle tone and pupillary reaction are noted.
- Alertness: Normal children exhibit awareness and interest in their surroundings. It is important to determine if the child is confused, irritable, lethargic or totally unaware of the environment. Changes in level of consciousness can also be rapidly assessed by using the mnemonic—AVPU.
- Awake
- Responsive to Voice
- Responsive to Pain
- Unresponsive.
- Distractibility or consolability by a parent is a normal phenomenon in infants and young children. Children who are not distracted or consoled by the caregiver should be carefully assessed.
- Eye contact with parents or physician is noted normally after 2 months of age. Failure to do so is an early sign of cortical hypoperfusion and or brain dysfunction.
- Speech/cry: It should be noted whether the cry is normal, whimpering, moaning or high-pitched.
- Motor activity: A note should be made of the movement of the trunk and limbs. An assessment should be made of the muscle tone. A child who is limp and hypotonic is compromised.
- Color of the skin reflects skin perfusion and indirectly—the respiratory and circulatory status. The skin of the palm and fingers may be pink (normal), pale, cyanosed, mottled or ashen grey depending on the degree of compromise.
- Posturing: Intermittent flexor (decorticate) or extensor (decerebrate) posturing occur with prolonged cerebral hypoperfusion.
- Pupil size: Pupils may be small but reactive in cerebral hypoperfusion. Unequal pupils are a medical emergency; may indicate raised intracranial pressure or an intracranial bleed.
AIRWAY
One needs to assess whether the airway is patent (open or unobstructed) or maintainable with adjuncts like oropharyngeal or nasopharyngeal airways, suction, positioning or requires tracheal intubation to be maintained.
To assess upper airway patency:
– Look for movement of the chest or abdomen
– Listen for breath sounds and air movement
BREATHING
Assessment of breathing includes the evaluation of respiratory rate, respiratory effort, tidal volume, airway and lung sounds and pulse oximetry.
Respiratory rate: Tachypnea is an early sign of respiratory distress. Tachypnea without increased work of breathing (quiet tachypnea) is seen in shock, heart disease and acidosis (a response of the body to wash out carbon dioxide and usually denotes acidosis). A slow or irregular respiratory rate in an acutely ill child is ominous.
A respiratory rate consistently greater than 60 breaths per minute in a child of any age is abnormal and is a ‘red flag’.
A decrease in respiratory rate from a rapid to a more ‘normal’ rate may indicate overall improvement if it is associated with a better level of consciousness and reduced signs of air hunger and work of breathing.
A decreasing or irregular respiratory rate in a child with deteriorating level of consciousness however often indicates a worsening of the child's clinical condition. Abnormal respiratory rates are classified as tachypnea, bradypnea and apnea.
Tachypnea: It is often the first sign of respiratory distress in infants. Tachypnea without increased work of breathing (quiet tachypnea) is commonly seen in nonpulmonary conditions like high fever, pain, mild metabolic acidosis with dehydration and sepsis.
Bradypnea: Bradypnea or irregular respiratory rate in an acutely ill child is an ominous clinical sign as it often signals impending arrest.
Apnea: Defined as cessation of inspiratory airflow for 20 seconds or for a shorter period of time if accompanied by bradycardia, cyanosis or pallor.
Central: Absence of inspiratory muscle activity, usually from abnormalities in or suppression of the brain or spinal cord.
Obstructive: Inspiratory muscle activity without airflow.
Mixed: Mixed central and obstructive apnea.
Respiratory effort: Signs of respiratory effort reflect the child's attempt to improve oxygenation, ventilation or both.
Signs of increased respiratory effort include: Nasal flaring, chest retractions, head bobbing or see-saw respiration.
Retractions + stridor/inspiratory snoring = > Upper airway obstruction
Retractions + expiratory wheeze = > Lower airway obstruction Retractions + grunting/ labored respiration = > Lung tissue disease
Severe retractions may also be accompanied by head bobbing or see-saw respirations.
The cause of see-saw breathing in most children with neuromuscular disease is weakness of the abdomen and chest wall muscles.
Work of breathing: Increased work of breathing (IWB) indicates respiratory distress or respiratory failure. IWB is assessed by nasal flaring, grunting, intercostal, subcostal and suprasternal retractions. Head bobbing and see-saw respirations (severe chest retraction with abdominal distension) are more advanced signs of respiratory distress and respiratory failure. As long as the patient can maintain oxygenation and ventilation with this increased work of breathing (increased respiratory rate and increased respiratory effort resulting in nasal flaring, retractions and use of accessory muscles) he is said to compensate and is in respiratory distress. Once a state is reached where the status quo of oxygenation and ventilation is not maintained, the child is said to be in respiratory failure. These are clinical distinctions.
Air entry: Effective tidal volume is assessed by magnitude of chest wall excursion and auscultation for distal air movement. Decreased chest excursion or decreased distal air movement on lung auscultation in a child with apparently normal or increased respiratory effort suggests airflow obstruction or lung tissue disease.
Stridor indicates upper (extrathoracic) airway obstruction and may be because of foreign body airway obstruction, infections like croup, congenital airway abnormalities e.g. laryngomalacia, acquired airway abnormalities e.g. tumor or cyst, upper airway edema e.g. allergic reaction or swelling after a medical procedure.
Grunting is typically a sign of severe respiratory distress or failure from lung tissue disease and may indicate progression of respiratory distress to respiratory failure. Grunting can be caused by pulmonary conditions e.g. pneumonia, pulmonary contusion and acute respiratory distress syndrome, cardiac conditions e.g. myocarditis, congestive heart failure, abdominal conditions causing pain and abdominal splinting e.g. bowel obstruction, perforated viscus, appendicitis or peritonitis.
6Gurgling is a bubbling sound heard during inspiration or expiration due to airway secretions, vomit or blood.
Wheezing indicates lower (intrathoracic) obstruction due to conditions such as bronchiolitis, asthma, pulmonary edema, or an intrathoracic foreign body. Inspiratory wheezing suggests a foreign body or other cause of obstruction in the trachea or upper airway.
Crackles are sharp crackling sounds heard on inspiration. Moist crackles are heard in pneumonia, dry crackles in atelectasis and interstitial disease.
Skin Color and Temperature
This will be discussed with circulatory status.
CIRCULATORY STATUS
Circulation is assessed to find out if the cardiac output meets the tissue demands. Shock is defined as circulatory dysfunction in which there is inadequate delivery of oxygen and substrates to meet the metabolic demands of tissues. Circulatory status is assessed by the evaluation of skin color and temperature, heart rate, heart rhythm, blood pressure, pulses (peripheral and central) and capillary refill time. Heart rate changes alone may be too early a sign of derangement and are often nonspecific. By the time hypotension develops it may be very late and then shock is classified as decompensated shock. Hence, we evaluate the organs perfused to assess for effective circulation. End organ function is assessed by the evaluation of brain perfusion (mental status), skin perfusion and renal perfusion (urine output).
Heart rate: Heart rate should be appropriate for the child's age, level of activity and clinical condition. Tachycardia is a common response to a variety of stresses including shock. Hence its presence mandates further evaluation. Bradycardia in a critically ill child is ominous.
Heart rhythm: An irregular rhythm with no relationship to breathing may indicate an underlying rhythm disturbance, such as premature ventricular or atrial betas or variable heart block.
Pulse: Comparison of central (femoral, carotid and axillary) and peripheral (brachial, radial, dorsalis pedis and posterior tibial) pulses should be done. The presence, strength and volume of the pulses need to be assessed. One must be aware that a bounding 7 pulse does not necessarily denote good perfusion. The weakening of central pulses is a worrisome sign requiring very rapid intervention tp prevent cardiac arrest. Cold environment can cause vasoconstriction and a discrepancy between peripheral and central pulses. Beat-to-beat fluctuation in pulse volume may occur in children with arrythmias. Fluctuation in pulse volume with respiratory cycle (pulsus paradoxus) can occur in children with severe asthma and pericardial tamponade.
SKIN PERFUSION
- Temperature: When the ambient temperature is warm, the extremities should be warm. The peripheries start cooling when the cardiac output falls. Assessment of the temperature of the trunk and the extremities should be done simultaneously as cooling occurs from the periphery to the center. The environmental temperature of the child should be considered when evaluating skin color and temperature. Back of the hand should be used to assess the skin temperature.
- Color: Color of the skin reflects skin perfusion and indirectly respiratory and circulatory status. Skin of palm and fingers may be pink (normal), pale, cyanosed, mottled or ashen grey depending on the degree of compromise.
- Capillary refill time (CRT): This is checked by applying pressure on the skin or nail so as to cause blanching and assessing the time taken for the color to come back to normal. The normal CRT is less than 2 seconds. Frequent causes of sluggish, delayed or prolonged CRT include dehydration, shock and hypothermia. The exceptions are a rising temperature and cool ambient temperature. Warm septic shock can have a normal CRT. The extremity is being tested should be raised above the level of the heart to make sure that only venous refill is not being tested.
ORGAN PERFUSION
- Brain: Brain perfusion can be assessed by features already described in appearance, i.e. changes in level of consciousness, papillary responses, muscle tone and posturing.Sudden and severe cerebral hypoxia may be present with the following neurologic signs: Loss of muscle tone, generalized seizures, papillary dilatation and unconsciousness. Subtle signs like altered consciousness, irritability, lethargy and agitation alternating with lethargy should be watched for.Certain drugs (increased ammonia), metabolic conditions and raised intracranial pressure may cause alteration in neurologic signs.
- Renal: Urine output may not be useful in initial assessment in a critically ill child, but is useful in monitoring the child and in evaluation of renal perfusion.
BLOOD PRESSURE
Shock can be present with normal, increased or decreased blood pressure.
Shock is described as compensated as long as compensatory mechanisms are able to maintain a systolic BP within a normal range. When compensatory mechanisms fail and systolic BP drops, shock is then classified as hypotensive (previously known as decompensated shock). Early recognition and timely intervention are critical to halting the progression from compensated shock to hypotensive shock to cardiopulmonary failure and arrest. This progression is a typically accelerating process.
Warning signs that indicate progression from compensated to hypotensive shock include: Marked tachycardia, absent peripheral pulses, weakening central pulses, cold distal extremeties with very prolonged capillary refill, narrowing pulse pressure, altered mental status and hypotension.
By type, shock can be categorized into:
- Hypovolemic
- Distributive
- Cardiogenic
- Obstructive.
Hypotension or lower limit (5th percentile) of blood pressure is defined by the following thresholds:
An observed fall of < 10 mm Hg in systolic BP from the baseline should prompt serial evaluations for additional signs of shock.
- Use a cuff bladder that covers ~40 % of the mid upper arm circumference
- BP cuff should extend at least 50–75% of the length of the upper arm.
Pulse oximetry: Oxygen saturation assessment is an important adjunct to identify oxygenation state in an acutely ill child. This is also called the fifth vital sign. Pulse oximetry should always be interpreted in conjunction with the clinical assessment and other signs such as respiratory rate, respiratory effort and level of consciousness.
Categorization
Based on the appearance, breathing and circulatory status, the physiologic status of a critically ill child should be categorized by type and severity as follows:9
Decide
Based on the assessment and initial categorization of the clinical condition, decide what to do.
Act
Initiate treatment (actions) appropriate for the child's condition and severity.
Remember to repeat the assess-categorize-decide-act cycle as you provide interventions.
For example; if a fluid bolus has been given then assess the child for any improvement as indicated by improved capillary refill, stronger pulses, improved urine output and a lower heart rate.
Disability
Disability assessment establishes the child's level of consciousness. Standard evaluation includes:
- AVPU pediatric response scale
- Glasgow coma scale
- Pupillary response to light.
Exposure
This is the final component of the primary assessment. Remove clothing as necessary an area at a time to carefully observe the child’ face, trunk, extremities and skin. Look for evidence of trauma or unusual markings suggestive of abuse.
SECONDARY ASSESSMENT
After completing the primary assessment and appropriate interventions to stabilize the child, the next priority is a focused history and physical examination.
The SAMPLE mnemonic may be useful:
S | Signs and symptoms |
A | Allergies |
M | Medications |
P | Past medical history |
L | Last meal |
E | Events |
TERTIARY ASSESSMENT
Consists of ancillary studies to detect and identify the presence and severity of respiratory and circulatory abnormalities.
Laboratory investigations like ABG, VBG, Hb concentration and non-laboratory investigations like pulse oximetry, exhaled carbon dioxide, capnography, chest X-ray and PEFR would help in assessing the respiratory abnormalities.
Further investigations would depend on the findings and working diagnosis from the initial assessment. They may entail anything from electrolytes to sophisticated imaging.
Stabilization: Depending on the physiologic status of the child, the following stabilization measures can be undertaken.
AIRWAY
Airway can be maintained by simple measures like allowing the child to assume a position of comfort. Avoid unnecessary agitation.
Head tilt chin lift maneuver can be used to open the airway unless cervical spine injury is suspected in which case jaw thrust without neck extension should be done.
The nose and oropharynx should be suctioned. Exercise caution in case of edema due to infection e.g. croup.
Foreign body airway obstruction relief technique should be done if the child is unresponsive (< 1 year of age-back slaps and chest thrusts, ≥ 1 year of age-abdominal thrusts).
Airway adjuncts like oropharyngeal or nasopharyngeal airways can be used if required e.g. in Pierre Robin Syndrome. Oral airway should be used only in an unconscious child.
Advanced interventions like endotracheal intubation, foreign body removal by laryngoscopy, application of CPAP (in case of swelling of soft tissues of upper airway due to inflammation) and cricothyrotomy may be required to maintain the airway patency.
It should be assessed whether the airway is maintainable or unmaintainable. If the airway is unmaintainable, nasopharyngeal or oropharyngeal airway or intubation is required. The patency of the airway is to be assessed and excessive secretions should be cleared. Airway should be opened by the appropriate maneuver.
BREATHING
Hundred percent humidified oxygen should be provided to any critically ill child irrespective of the physiologic status. Use a high concentration non-rebreathing system if available. Monitor oxygen saturation continuously.
If the child has Respiratory Distress the child is kept with the caregiver, is allowed to maintain a position of comfort, and oxygen is provided in a non-threatening manner. Turbulent airflow leads to increased airway resistance; hence the child should be kept calm.
- An increased respiratory rate, particularly with signs of distress (e.g. increased respiratory effort including nasal flaring, retractions, see-saw breathing, or grunting)
- An inadequate respiratory rate, effort, or chest excursion (e.g. diminished breath sounds or gasping), especially if mental status is depressed
- Cyanosis with abnormal breathing despite supplementary oxygen.
If the child has Respiratory Failure, the approach is more aggressive. In case of inadequate chest expansion or respiratory arrest, bag and mask ventilation should be given with 100% oxygen. Tracheal intubation may be required.
Tracheostomy or cricothyrotomy may be required in cases of complete upper airway obstruction caused by diphtheria, severe orofacial injuries or laryngeal fractures.
CIRCULATION
A stable, normotensive child should be allowed to remain with the caregiver while an unstable child should be put in the Trendelenburg position.
High-flow oxygen is indicated in all children with shock.
Once airway and breathing have been stabilized, vascular access is to be secured. Intraosseous route may be used in case of collapsed veins. No child should die due to a lack of vascular access. Any drug can be infused using this route provided it is followed by a flush of fluid to get the drug in the central circulation.
Fluid resuscitation should be given. Isotonic crystalloids like normal saline or ringer lactate is preferred over colloids. Give fluids as a 20 ml/kg bolus over 5–20 minutes. The child needs to be monitored after administration of each fluid bolus. The rate of administration and the number of boluses depend on the type of shock. Repeat boluses should be given till the blood pressure and tissue perfusion is restored. Blood products should be administered only when specifically indicated for replacement of blood loss or for correction of coagulopathies.
The SPO2, heart rate, blood pressure, pulse pressure, mental status, temperature and urine output should be monitored frequently to evaluate trends and determine response to therapy.
Conduct ancillary laboratory and non-laboratory studies to help in identification of the etiology and severity of shock, evaluation for organ dysfunction, identification of metabolic derangements and evaluation of the response to therapeutic interventions.
When the circulation does not improve with fluid boluses alone, inotropes, phosphodiesterase inhibitors, vasodilators and vasopressors are used.
The goal of therapy is to improve the perfusion and correct the hypotension.
Arrhythmias if present need to be corrected.
CNS SUPPORT
Seizures should be controlled by anticonvulsants. Raised intracranial pressure is to be corrected by appropriate measures.12
FURTHER READING
- Cummins RO, Hazinski MF. The most important changes in the international EED and CPR Guidelines 2000. Circulation. 2000; 102: I371-6.
- Eisenberg MS, Mengert TJ. Cardiac resuscitation. N Engl J Med. 2001; 344: 1304-13.
- Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 9: Pediatric basic life support. The American Heart Association in collaboration with the International Liaison Committee on Resuscitation. Circulation. 2000; 102: 1253-90.
- Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care: Part 10: Pediatric advanced life support. The American Heart Association in collaboration with the International Liaison Committee on Resuscitation. Circulation. 2000; 102: 1291-342.
- Kochanek MK, et al. Cerebral resuscitation after traumatic brain injury and cardiopulmonary arrest in infants and children in the new millennium. Pediatr Clin North Am. 2001; 48: 661-81.
- Mathers LH, et al. Anatomical considerations in obtaining venous access. Clin Anat. 1992; 5: 89106.
- Hazinski MF (Ed). PALS provider manual. American Academy of Pediatrics. American Heart Association. 2006; 1-109.
- PALS guidelines 2010 from AHA Part 14: Pediatric advanced life support: 2010. American Heart Association. http://circ.ahajournals.org/cgi/content/full/122/18_suppl_3/S876