Specificity of UPV in patients with Asthma bronchiale/High School (nurse)

Epidemiology

• 3-6% of the population (1993 - 6.4%) generally a permanent increase !
• Asthmatic condition – mortality 12% in intubated patients and 1–2% in non-intubated patients.
• 80% of patients who died with status asthmaticus have bronchial asthma for more than 5 years.
• The so-called refractory asthma only about 5% of all patients.

Basic characteristics

• Bronchoconstriction.
• Airway edema
• Hyperreactivity of DCs to various stimuli.
• Airway remodeling.
• An asthma attack is triggered by SMOKING, dust, pollen, dust mites, drugs (THP, beta blockers, ANP,...), cold, physical exertion.

Pathophysiology from the point of view of UPV

• Increased resistance in DC.
• Air trapping.
• Hyperinflation.
• An increase in the negativity of pleural pressures.
• Increase in functional residual capacity, residual volume and total lung capacity.
• An increase in the ventilation-perfusion ratio.
• Increase in dead space and alveolar ventilation (until exhaustion, then decrease).‏‏

Treatment of acute exacerbation

• Higher FiO 2 and high flow oxygen.
• Inhaled β-mimetic until signs of overdose (aerosol, spacer).
• Systemic or inhaled steroids (120–180 mg Methylprednisone/24 hours in 3–4 doses after 48 hours → 60–80 mg until the patient's condition improves).
• Aminophylins in infusion.
• Mucolytics.
• ATB only in case of infection.

Non-standard methods of bronchodilation

• Ketamine 10-40 ucg/kg/min ?
• Magnesium up to 10 g/24 hours.
• NO.
• Helium (the earlier and in more seriously ill patients, the greater the benefit)‏.

UPV in Asthmatics

• UPV complicated and risky.

Indication

• Impairment of consciousness.
• Respiratory rate above 40 D/min.
• Rising/falling pulsus paradoxus.

= Heart rate whose waves are smaller during inhalation than during exhalation systolic pressure decreases during inspiration. As a result of the increase in the volume of blood in the chest during inspiration, this difference is to a certain extent physiological.

• PDrop in pO 2 below 7.5 kPa.
• Rise of pCO 2 above 7 kPa → acidosis.
• Persistent lactic acidosis.
• Barotrauma.
• Silent chest despite patient's inspiratory efforts.
• Inability to communicate, muscle fatigue, exhaustion.

Use of ventilation mode

The goal of UPV is ventilation and oxygenation support and prevention of extreme pH changes and severe hypoxia.

• The basis is controlled hypoventilation and permissive hypercapnia.
• Volume-controlled ventilation with constant inspiratory flow is more suitable.
• Respiratory rate less than 10 D/min. with a 1:3 to 1:4 ratio of inspira to expiria.
• Low PEEP 2–4 cmH 2 O → distance therapy (keeping the lung open).
• The patient is semi-sitting.
• If there are no complications, the time for UPV in a critical condition is 3-5 days.
• Extubation when bronchospasm resolves, decreased secretion production, good muscle strength.

Complications of UPV

• Hypotension.
• PNO.
• Arrhythmia.
• ETI dislocation.
• Pneumonia.
• Circulation failure.
• KBleeding into the GIT.
• Pulmonary embolization.
• Pneumomediastinum.
• Subcutaneous emphysema.

Asthma bronchiale in children

• More heterogeneous character and time course different from adults.
• 10% of children.

A predisposed individual.

• Repeatedly in contact with adverse environmental influences (polluted air, smoking, unhealthy lifestyle and nutrition, etc.) → contact with the so-called trigger (allergen, exertion, smoke, viral infection, etc.) → airway obstruction (contraction of the smooth muscles in the bronchi, mucosal swelling and increased mucus secretion) with symptoms of expiratory dyspnea and cough.
• The most common cause of exacerbation in childhood is viral infections.

Causes of asthma problems in children

• The etiology varies in different periods.
• Respiratory viruses:

• Infants/toddlers - temperatures are often present → very good prognosis even with recurrences; usually disappear by school age.

• the exception is especially human rhinoviruses, which damage the mucous membrane of the bronchi and thus can contribute to the later development of persistent asthma.

• Allergies.

• Atopic predisposition → worse prognosis, often progression to persistent asthma.

• The later obstructive bronchitis manifests itself in childhood, the more likely the allergic etiology and progression to persistent asthma.

• Other.

• Physical stress, stress, cigarette smoke, etc. → less often in children, schoolchildren/adolescents.

• Around the age of 3, 3 basic groups of children are symptomatically intertwined:

• The so-called transient wheezers → children who "grow out" of the problem on their own.
• Non-atopic wheezers → děti s poškozenými dýchacími cestami v důsNon-atopic wheezers → children with damaged airways due to infection, this defect is reversible in case of non-allergenic terrain.
• Real asthmatics.

Investigation

• Medical history - family history, especially atopy, smoking, pets,...
• Laboratory height – inflammatory markers, …
• Immunological examination including total IgE and ECP, possibly. specific IgE.
• Spirometry (approx. from 3-4 years).
• Whole-body body plethysmography → an airtight chamber allowing pressure and volume changes that take place inside to be measured (also possible in non-cooperative children).

Asthma predictive index

• Major criteria – asthma in the parents, atopic eczema in the child, sensitivity to airborne allergens.
• Small criteria – wheezing outside the cold season, eosinophils in the blood count >4%, food sensitivity

→ presence of one major or 2 minor criteria → probability of asthma.

Therapy

Acute bronchial obstruction

• The 1st choice is short-acting inhaled bronchodilators → β 2 -mimetic (salbutamol), anticholinergic (ipratropium bromide) newly questionable meaning.
• In the case of insufficient effect or severe p.os course; and corticosteroids.
• Hospitalization if the clinical condition does not improve after 3 repeated inhalations of bronchodilators.

Long-term treatment

• Indicated if the frequency or severity of exacerbations significantly impairs quality of life and asthma is not under control (control criteria same as for adults).
• 1st choice of inhaled corticosteroids (treatment effectiveness is evaluated after at least 3 months),

→ after control is achieved, the dose is reduced to the lowest level,

→ if there is insufficient control,

→ → necessary control of correct use, compliance with measures → if in order,

→ increase the dose of inhaled corticosteroids (ICS) or add a leukotriene receptor antagonist (montelukast = Singulair).

• Long-acting β 2 mimetics (=LABA) – they are not recommended in monotherapy, in combination only if ICS alone are not enough.
• Measures to eliminate causative agents.

Inhaler attachments

• Significant simplification of inhalation, coordination of inhalation and squeezing is eliminated.
• Wash the spacer and let it dry, do not wipe!!!! → formation of static electricity trapping particles.
• 1 injection from the dispenser = 5-10x calm inhalation and exhalation without removing the dispenser and spacer.

Determining the fullness of the aerosol dispenser

• Immerse the dispenser in the water and determine the fullness of the dispenser according to the drop towards the bottom (see picture).

File:Bombicky.jpg

Aerosol dispenser

Adverse effects of ICS

• LOCAL:

• Common: oropharyngeal candidiasis, throat, tongue, pharynx, esophagus irritation, cough.
• More rarely: early and delayed hypersensitivity reactions in the face, lips, eyes, pharynx, redness, rash, urticaria, eczema, swelling, angioedema, bronchospasm.

• SYSTEMS:

• To varying extents with all ICS, they are dose-dependent, but long-term negative effects on children's development have not been proven.
• Adrenal effects - cortisol synthesis.
• Induction of osteoporosis, slowing of growth rate.
• Psychological changes.
• At high doses, deterioration of healing, atrophy of the skin.
• Disorders of glucose tolerance.
• Increased incidence of glaucoma and cataracts.

Links

• Asthma

Source of information

• VOJTÍŠEK, Petr. Bronchial asthma in children and adults [lecture for subject Modul UPV, specialization Intensive care nurse - postgraduate study, Higher vocational school medical school Secondary and higher medical school Ústí nad Labem]. Ústí nad Labem. 18.12. 2011. 

• DOSTÁL, Pavel, et al. Fundamentals of artificial pulmonary ventilation. 2. edition. prague : Maxdorf, 2005. ISBN 80-7345-059-3.