30. Pediatric Intensive Care

Daniel Alexander¹

(1)

Paediatric Critical Care Unit, Perth Children’s Hospital, Nedlands, WA, Australia

Daniel Alexander

Email: Daniel.Alexander@health.wa.gov.au

Keywords

Recognition of the seriously ill childTransfer to pediatric intensive careAcute severe asthma in childrenMeningococcemia, treatmentDiabetic ketoacidosis children

30.1 Recognition of the Seriously Ill Child

History, examination and judicious investigation will direct assessment of the pediatric patient. This process is easier for the anesthetist familiar with physiology in the young. However, there are several clear indicators of the critically ill infant. These are alertness and interaction, breathing, circulation and fluid balance over the preceding 24 h. Seriously ill children look tired or weak, do not resist examination or procedures such as IV insertion and are often pale or dusky. They are likely to be tachypneic, tachycardic and with signs of respiratory failure, cardiac failure, or both. The critically ill infant may also have a previously unrecognized congenital disorder. These and other conditions that should be considered in a critically unwell infant are listed in Table 30.1.

Table 30.1

Conditions to always consider in the critically ill infant

Diagnoses to consider in the critically ill child
Sepsis (Group B Streptococcus, Meningococcus, UTI, Meningitis)
Duct dependent congenital cardiac lesions (Coarctation, HLHS)
Gut obstruction (volvulus, malrotation, intussusception)
Metabolic disorders
Non-accidental injury

HLHS Hypoplastic Left Heart Syndrome

It is always wise to listen to the parent or caregivers who know their child best and are often able to detect changes from normal for their child. They can be of particular help with children who have complicated histories. ‘Red flags’ in the history include apnea, bilious vomiting (intestinal obstruction), seizures, intermittent abdominal pain and leg drawing (intussusception), rash (meningococcemia) and episodes of color change. Examination should assess the overall appearance of the child, vital signs including blood pressure (normal values Table 30.2), the adequacy and effectiveness of breathing, and the adequacy of cardiac output. Perfusion of the peripheries is especially helpful in assessing circulation, as blood pressure is maintained until late in illness.

Table 30.2

Normal ranges for heart rate and respiratory rate

Age	Heart rate (beats/min)	Respiratory rate (breaths/min)
<30 days	110–170	30–60
6 months	100–160	30–40
1 year	100–150	30–40
2 years	95–140	25–30
4 years	90–130	25–30
6 years	80–120	20–25
8 years	80–120	20–25
10 years	80–110	15–20
12 years+	60–100	15–20

Expected systolic blood pressure = 80 + (age in years × 2) mmHg

Tip

There is little to lose by resuscitating a child whom in hindsight didn’t need it, but there is much to be lost in a delay.

A child who looks critically unwell (hypoxic, mottled, grey, poorly perfused, drowsy), is bradycardic and relatively hypoventilating has already reached the point of decompensation and is about to arrest. If ever there is doubt about the need to mask ventilate in this situation, the answer is a resounding “Yes!”. If ever there is doubt about the need to perform chest compressions, the answer will most likely be “Yes”, (and it probably needed to be started a couple of minutes earlier).

Keypoint: Detecting the Seriously Ill Child

Alertness and interaction

Breathing: rate, effort and saturation

Circulation: heart rate and perfusion

Relative hypoventilation and bradycardia can be ominous

Fluid balance

30.2 Recognition of the Deteriorating Child

Early recognition of the deteriorating child followed by prompt and effective action can minimize events such as cardiac arrest, and may reduce the level of intervention required to stabilize the child. The evidence base for recognition and response systems for the deteriorating child is still developing. Changes in the child’s observations often occur 8–96 h before events such as cardiorespiratory arrest or unplanned admission to intensive care. Several tools have been developed to recognize the deteriorating child, most of which plot physiological observations in a graphical form to display trends. Graphical documentation is recommended because changes over time are easier to recognize.

The most important method to detect a child who is deteriorating is regular measurement, documentation and review analysis of observations. Standard observations include respiratory rate, oxygen saturation, heart rate, blood pressure, temperature and level of consciousness. The importance of monitoring blood pressure is often overlooked in institutions unfamiliar with dealing with critically unwell children. Other observations (such as seizure activity or BSL) may also be relevant for particular children.

Failure to respond to therapy may also indicate relative deterioration despite unchanged physiological parameters. For example, a child with severe upper airway obstruction who does not respond to multiple epinephrine (adrenaline) nebulizations and steroids may require intensification of management.

30.3 Intervention and Stabilization Before Transfer

After recognizing the child who is seriously ill or deteriorating, treatment is begun or increased to avoid cardio-respiratory arrest and to facilitate recovery. Most pediatric health care systems operate within a centralized model, with advice available from on call pediatric intensivists in specialized centers. Whilst anesthetists are well equipped to treat seriously ill children, early consultation with these centers ensures the appropriate interventions and transfer of patients. Management may be influenced by geographical and logistical considerations. For example, a child with acute severe asthma in an isolated rural hospital may be more safely managed locally with intravenous steroids, aminophylline and continuous salbutamol inhalation than with intubation, ventilation and transfer by aeromedical retrieval.

Several problems commonly occur during transfer to pediatric intensive care units. These problems are hypoventilation, hypoxemia, hypotension, hypoglycemia, hypothermia, unrecognized seizures, and lack of attention to cerebral perfusion pressure. Every patient needs at least one well-secured peripheral intravenous, intraosseous or central access. If transfer is expected to take some time, a second access site should be considered.

Keypoint

Common problems during transfer to PICU are hypoventilation, hypoxemia, hypotension, hypoglycemia, hypothermia, unrecognized seizures, and inadequate cerebral perfusion pressure.

If the patient is ventilated, the endotracheal tube needs to be the correct size and well placed. If possible an X-ray should be taken after any intubation to ensure optimal position (neither endobronchial nor too high that may risk dislodgement). On chest x-ray the tip of the ETT should sit in the mid trachea, below the clavicular heads and well clear of the carina. The endotracheal tube needs to be of a size that there is not an excessive leak and ventilation can be assured. A cuffed ETT is preferable in most situations and highly desirable if high inspiratory pressures are anticipated. Cuffed ETT are routinely used in most critical care areas. They have the benefits of not needing to ‘up-size’ the ETT because of an excessive and unmanageable leak, and protection from airway soiling. Nasal ETTs are less mobile than oral tubes and are preferred by many units. Prolonged nasal intubation in adults may cause sinusitis, but this is not a problem in children. However, a secure, well placed oral ETT is perfectly acceptable and more straightforward to insert (See Chap. 18 Dental Anesthesia, Sect. 18.1).

30.4 Specific Conditions

30.4.1 Croup

Tracheolaryngobronchitis (croup) is a viral infection causing inflammation and narrowing of the upper airway. It is usually caused by parainfluenza (type 1 and 2) although other viruses such as rhinovirus, influenza A and B, adenovirus, and respiratory syncytial virus can produce a similar clinical picture. Young children have small upper airways and so are more at risk of respiratory obstruction than older children. Croup is a common reason for admission to pediatric intensive care. Often there is a history of a prodromal illness and ‘seal-bark’ cough. Stridor is high pitched and initially inspiratory, but as obstruction worsens it becomes biphasic and at rest. Stridor is absent when the obstruction and respiratory distress worsen. Cyanosis in air is seen just before respiratory arrest. Using supplemental oxygen to treat a child who has upper airway obstruction removes desaturation and cyanosis as markers of deterioration. For this reason, supplemental oxygen is given with caution and in an area of high acuity.

Croup is diagnosed after other conditions have been excluded. A differential diagnosis includes epiglottitis, bacterial tracheitis, angioedema, foreign body and retropharyngeal abscess. At times croup will present with an element of reactive lower airway disease (‘Crasthma’ or ‘wheezy croup’). It is difficult to determine if a child has croup or epiglottitis. Children with croup have a hoarse voice (laryngo), cough (bronchitis) and are not systemically unwell despite having viremia and a high fever. Children with epiglottitis are septic and don’t cough (Table 30.3).

Table 30.3

Comparison between signs and symptoms of croup and epiglottitis

Croup	Epiglottitis
Common illness of childhood	Rare
Viral etiology	Bacterial etiology
Hoarse voice	Sit forward and drool
Cough	No cough
Not systemically unwell	Septic and look unwell
Fever	Fever
Vocal cords usually easily visualized	May be very difficult to visualize cords