Background
The burden of acute respiratory diseases in children in Italy
Risk factors
Pharmacology of corticosteroids
Anti-inflammatory action
Cells | Factors involved in the inflammatory response | Comments |
---|---|---|
Macrophages and monocytes | Cascade of arachidonic acid (prostaglandins and leukotrienes) | Mediated by inhibition of PLA2 and reduced COX-2 expression. |
Inflammatory cytokines (e.g., IL-1,2,4,5,6,11,13) and TNF-α | Reduced production and release. | |
Cytokines exert multiple effects on inflammation, e.g., T-cell activation and stimulation of fibroblast proliferation. | ||
Endothelial cells | ELAM-1 and ICAM-1 | ELAM-1 and ICAM-1 are important for extravasation of leukocytes into tissues. |
Basophils | Histamine and LTC4
| IgE-dependent release inhibited by glucocorticoids. |
Fibroblasts | Arachidonic acid | See “Macrophages and monocytes”. Glucocorticoids also reduce the proliferation of fibroblasts. |
Lymphocytes | Cytokines (IL-1, IL-2, IL-3, IL-6, TNF-α, GM-CSF, interferon-γ) | See “Macrophages and monocytes”. |
Mechanism of action
Pharmacokinetics
Glucocorticoids in medical practice
Glucocorticoid | Equivalent dose (mg) | Anti-inflammatory potency* | Salt retention* | Suppressive HPA potency* | Biological half-life (h) | |
---|---|---|---|---|---|---|
Hydrocortisone | 20 | 1 | 1 | 1 | 8–12 | Short |
Cortisone | 25 | 0.8 | 0.8 | 1 | 8–12 | Short |
Prednisolone | 5 | 4 | 0.8 | 1 | 12–36 | Intermediate |
Prednisone | 5 | 4 | 0.8 | 1 | 12–36 | Intermediate |
Methylprednisolone | 4 | 4–5 | 0.2–0.5 | 5 | 12–36 | Intermediate |
Triamcinolone | 4 | 5–10 | 0 | 5 | 12–36 | Intermediate |
Dexamethasone | 0.75 | 25 | 0 | 50 | 36–72 | Long |
Betamethasone | 0.75 | 25 | 0 | 50 | 36–72 | Long |
Tolerability
Withdrawal symptoms
Adrenocortical insufficiency
Cardiovascular instability | |
Discrepancy between disease severity and clinical status of the patient presenting nausea | |
Orthostatic hypotension | |
Dehydration | |
Lower abdominal pain or weight loss | |
Fever of unknown origin | |
Apathy, depression not related to psychiatric illness | |
Altered pigmentation, loss of axillary and pubic hair | |
Hypothyroidism and hypogonadism | |
Hypoglycemia, hyponatremia and hyperkalemia | |
Neutropenia and eosinophilia |
Factors favoring suppression of the HPA axis
The glucocorticoid used
The glucocorticoid administration schedule
Route of administration
Duration of corticosteroid treatment and cumulative dose
How to reduce the risk of HPA suppression
Recovery of the HPA axis
Summary
ᅟ | ᅟ |
• Glucocorticoids prevent or suppress inflammation in response to immunological, radiant, mechanical, chemical and infectious stimuli. • Oral glucocorticoids are well absorbed and effective. • Glucocorticoids have been associated with adverse effects, mainly in relation to dosage, type of glucocorticoid and treatment duration. • Prolonged glucocorticoid treatment can be associated with suppression of HPA axis function and growth retardation. • Administration of glucocorticoids with a short or intermediate biological half-life (e.g., prednisolone or prednisone) for 3–6 days is not associated with withdrawal symptoms. |
Bronchiolitis
Epidemiology, age frequency and seasonality
Main risk factors
Clinical presentation and severity
-
Cough.
-
Tachypnea or apnea (especially in preterm infants below the age of 3 months).
-
Increased respiratory effort (grunting, nasal flaring, and intercostal, subcostal or supraclavicular retractions).
-
Inspiratory crackles and expiratory wheezing at auscultation.
-
Low oxygen saturation (SatO2).
-
Dehydration due to feeding difficulties.
Possible discharge | Brief observation | Hospitalization | |
---|---|---|---|
Respiratory effort | None or mild chest wall retraction | Tracheal tug, nasal flare, Moderate chest wall retraction | Moderate-to-severe respiratory distress, apnea |
Oxygen saturation | No supplemental oxygen requirement, saturations > 95% | Saturations 90–95% | Saturations persistently < 90–92%, O2 requirement |
Feeding | Normal to slightly decreased | 50–75% of normal feeds | <50% of feeds, unable to feed, dehydration |
Gestational age | Gestational age >37 weeks, birth age >12 weeks | Gestational age <37 weeks, birth age <6–12 weeks | |
Responsivity and alertness | Reactive, vigilant | Less or not responsive | |
Social factors | Good parent compliance, hospital easily accessible | Non-collaborative parents, Distant from hospital | |
Preexisting risk factors | No risk factors | BPD, cystic fibrosis, cyanogenic congenital heart disease, immunodeficiency, neuromuscular disease | BPD, cystic fibrosis, cyanogenic congenital heart disease, immunodeficiency, neuromuscular disease |
Management and treatment
Environmental and pharmacological prophylaxis
Summary
ᅟ | ᅟ |
• Bronchiolitis is the most frequent cause of lower respiratory tract infection in the first year of life, with 60–80% of cases caused by RSV, and with the highest rate of hospitalization occurring in infants < 2–3 months of age. • Infants < 3 months old, preterm infants, infants with chronic lung diseases (bronchopulmonary dysplasia or cystic fibrosis), congenital heart or neuromuscular diseases, and infants with immunodeficiency have an enhanced risk of hospitalization. • Cough, rhinorrhea, low grade fever, tachypnea or apnea, and symptoms of lower tract respiratory infection (grunting, chest retractions, crackles and wheezing) may be present. • Oxygen supplementation and supportive therapy to control hydration remain the mainstay of treatment. • There is no evidence supporting the use of salbutamol, nebulized adrenaline or inhaled or oral corticosteroids in routine practice. • RSV bronchiolitis, especially when severe, increases the risk of developing recurrent wheezing and asthma later in life. |
Wheezing in the preschool child
Phenotypic classifications
Asthma in preschoolers: diagnosis
Treatment of wheezing in preschoolers
Summary
ᅟ | ᅟ |
• Preschool wheezing is a heterogeneous condition that generally resolves by school age, but may represent the first manifestation of asthma in some children. • It is characterized by different clinical and pathophysiologic features. • Therapeutic strategies in preschool children with recurrent wheezing should be tailored to the frequency and severity of clinical manifestations. • The evidence supporting early family/carer-initiated oral corticosteroids in the home management of exacerbations is weak, and this treatment is not indicated for preschool children with mild exacerbation of viral wheeze. • According to the GINA guidelines, oral corticosteroids are indicated in children with severe wheezing exacerbations. |
Asthma
Management of asthma in the emergency department
Clinical signs | Mild | Moderate | Severe | Life-threatening |
---|---|---|---|---|
Able to talk | Able to talk in sentences | Cannot complete sentences | Able to pronounce a few words | - |
Respiratory ratea
| Normal | Increased | Greatly increased | Bradypnea/gasping |
Heart rateb
| Normal | Increased | Greatly increased | Fall in heart rate |
Complexion | Normal | Pallor | Pallor/cyanosis | Cyanosis |
Level of consciousness | Normal | Restlessness | Severe restlessness | Obtundation, drowsiness |
Wheezing | Mild expiratory | Expiratory | Expiratory/Inspiratory | Silent chest |
Use of accessory muscles of respiration | Absent | Mild | Moderate | Paradoxical respiratory movement |
SpO2 | >95% | 92–95% | <92% | <90% |
PaCO2 (mmHg) | <38 | 38–42 | >42 | >42 |
Peak expiratory flow | >80% | 60–80% | <60% | Not measurable |
Pharmacological treatment of an asthma attack
Short-acting beta2-agonists
Ipratropium bromide
Epinephrine hydrochloride
Corticosteroids
Other therapies
Management of an asthma attack in children aged > 5 years
Summary
ᅟ | ᅟ |
• Asthma is one of the most common causes of emergency department visits. • Treatment of asthma depends on the severity of the attack. | |
• The severity of the asthma attack must be rapidly evaluated upon arrival in the emergency department. | |
• Short-acting beta2-agonists represent the rescue medication of choice and should be taken as needed to reverse bronchoconstriction and relieve symptoms. • Oral corticosteroids should always be used in case of moderate and severe asthma attacks since they result in fewer and shorter hospitalizations. • According to international guidelines, a liquid formulation of oral corticosteroids is preferred to tablets in children. |
Laryngotracheitis in children
Etiology and epidemiology
Clinical history
Diagnosis
Anteroposterior anterior neck radiograph can help to establish an alternative diagnosis in patients with atypical disease. | |
• Cone-shaped narrowing instead of the normal squared shoulder appearance of the subglottic area suggests croup.
| |
• A ragged edge or a membrane spanning the trachea suggests bacterial tracheitis.
| |
• Thickening of epiglottis and aryepiglottic folds suggest epiglottitis.
| |
• Bulging of the posterior pharynx soft tissue suggests retropharyngeal abscess.
|
Differential diagnosis
Feature | Laryngotracheitis | Epiglottitis | Bacterial tracheitis | Spasmodic croup |
---|---|---|---|---|
Viral prodromal illness | ++ | - | + | + |
Mean age | 6–36 months | 3-4 years | 4-5 years | 6–36 months |
Illness onset | Gradual | Acute | Acute | Sudden |
Fever | +/- | + | + | - |
Quality of stridor | Harsh | Mild | Harsh | Harsh |
Drooling, neck hyperextension | - | ++ | + | - |
Cough | ++ | - | ++ | ++ |
Sore throat | +/- | ++ | +/- | - |
Recurrence | + | - | - | ++ |
Hospitalization and intubation | Rare | Frequent | Frequent | Rare |
Management and treatment
Stridor | None: 0 |
With agitation: +1 | |
At rest: +2 | |
Chest wall retractions | None: 0 |
Mild: +1 | |
Moderate: +2 | |
Severe: +3 | |
Cyanosis | None: 0 |
With agitation: +4 | |
At rest: +5 | |
Level of consciousness | Normal: 0 |
Disoriented: +5 | |
Air entry | Normal: 0 |
Decreased: +1 | |
Markedly decreased: +2 |
Summary
ᅟ | ᅟ |
• Laryngotracheitis, also known as ‘viral croup’, is the most common and typical form of croup, and refers to viral infection of the glottis and subglottic regions. • The child with laryngotracheitis presents a harsh cough, described as ‘barking’ or ‘brassy’, inspiratory stridor, hoarseness, low grade fever and respiratory distress that may develop slowly or quickly. • Severity can be assessed by the Westley croup score (WCS). • Anteroposterior radiographs of the neck are rarely indicated and should be considered in a child in whom the diagnosis is unclear or who does not respond as expected to treatment. • Laryngotracheitis is often mild and self-limiting and resolves without any active intervention. • Oral corticosteroids are the treatment of choice for children with mild-to-moderate croup whereas inhaled corticosteroids and nebulized epinephrine are indicated for children with severe respiratory distress. |
Treatment of acute respiratory failure in children
Cause | Physiological or anatomical basis |
---|---|
Metabolism ↑ | O2 consumption ↑ |
Risk of apnea ↓ | Immaturity of control breathing |
Airway resistance ↑
| |
Upper airway resistance ↑ | Nose breathing |
Large tongue | |
Airway size ↓ | |
Collapsibility ↑ | |
Pharyngeal muscle tone ↓ | |
Compliance of upper airway structure ↑ | |
Lower airway resistance ↑ | Airway size ↓ |
Collapsibility ↑ | |
Airway wall compliance ↑ | |
Elastic recoil ↓ | |
Lung volume ↓ | Numbers of alveoli ↓ |
Lack of collateral ventilation | |
Efficiency of respiratory muscles ↓ | Efficiency of diaphragm ↓ |
Rib cage compliance ↑ | |
Horizontal insertion at the rib cage | |
Efficiency of intercostal muscles ↓ | |
Horizontal ribs | |
Endurance of respiratory muscles ↓ | Respiratory rate ↑ |
Fatigue-resistant type I muscle fibres ↓ |
-
Type 1, which is defined as hypoxemia without hypercapnia. Conditions more often leading to type 1 respiratory failure are characterized by altered ventilation/perfusion.
-
Type 2, which is determined by hypoxia with hypercapnia. The most frequent causes are increased airway flow resistance and a decreased surface for gas exchange.
Management
Hypoxemia and normocapnia
-
Face mask. This is connected to an oxygen source and placed over the patient’s nose and mouth. At high oxygen flow rates, room air can be entrained through the small perforations in the mask, whereas low-flow rates may lead to carbon dioxide retention. The concentration of oxygen delivered varies depending on two factors: the patient’s respiratory flow rate and oxygen flow [79]. A face mask interferes with feeding.
-
Hood. This is a transparent plastic box placed around the infant’s head [80]. It requires high oxygen flow rates (>5 L/min) to prevent re-breathing of carbon dioxide [79]. This method enables delivery of a specific fraction of inspired oxygen (FiO2). It limits the infant’s mobility and interferes with feeding.
-
Nasal cannulae or prongs. These devices deliver oxygen directly into the patient’s nostrils. They can be either low-flow or high-flow (HFNC) and humidification is required with a flow rate >4 L/min [81]. In low-flow oxygen treatment, FiO2 varies in relation to the patient and to the type of prongs, and it is not possible to determine the amount of FiO2 reaching the patient’s airway [79, 80]. On the contrary, with HFNC, the exact amount of FiO2 reaching the airway can be calculated and modulated irrespective of oxygen flow.
-
In a pediatric setting in which the patient’s clinical course can be closely monitored.
-
If there is a sufficient number of staff well trained to recognize the early signs of respiratory failure.
Hypoxemia and hypercapnia
Summary
ᅟ | ᅟ |
• Because of differences in respiratory physiology, children are more susceptible than adults to severe manifestations of respiratory diseases, which in some cases lead to blood oxygen desaturation. • Hypoxemia associated with severe respiratory diseases is a major criterion for hospitalization and is more common in young patients. • Administration of simple oxygen is indicated when hypoxemia is the only complication and no hypercapnia is present. • Patients with significant respiratory distress may benefit from HFNC, helmet ventilation or CPAP. These procedures must be closely monitored and performed by trained staff. • If ventilatory support is needed, NIV is the method of choice whenever possible and safe. It doesn’t disrupt swallowing, feeding, speaking or coughing, and preserves the vocal cords and trachea. It also reduces the risk of infection and the length of stay in pediatric intensive care units. |