Respiratory
Failure (RF)
Is the pathological state, at which breathing organs are unable
to provide adequate saturation of organism by oxygen and destroy carbon dioxide.
Anatomic
and physiological features of respiratory organs
1. High
metabolism, greater necessities in oxygen, however less compensating
possibilities of organs of breathing;
2.
Uncomplete differentiation of
tissues;
3. Narrow respiratory tracts;
4. Undevelopment of additional
cavities of nose, absence of lower nasal passage;
5. Propensity to the edema of
mucous - through large amount of vessels (ventilation failure);
6. The features of larynx structure (tender of cartilaginous ring,
narrow upper space, expressed submucous tissue) ® croup.
•Tender trachea, bronchial tubes, little amount of elastic tissues ®
narrowing of respiratory road ® swollen mucus, hypersecretion of
bronchial glands ® obstructions (hypoventilation -emphysema);
• Undevelopment
of cilia epithelium ® propensity to violation of evacuation
function of respiratory tract;
•Lungs sanguineous,
small elastic and many connective tissue
® restrictive RF (exudation, аtelectasis, emphysema);
•Horizontal placing of ribs, low retractive ability of diaphragm ® diminish of
the excursion of lungs.
Etiology
of RF
The reasons
leading to the development of acute respiratory failure are a lot. The most
frequent causes of respiratory failure are listed below.
1. Obstructive
type
a) Obstruction of the upper respiratory tract may
occur when there are abnormalities of development (atresia choanae, Pierre
Robin syndrome, stenosis of the larynx above the vocal cords), aspiration of
gastric contents, or foreign body, infections (epiglottitis), allergic
laryngism, the tissue changes (tumor, cyst, hypertrophy of tonsils).
b) Obstruction of the lower airways may occur when there
are abnormalities of development (bronhomalacia, lobar Emphysema), aspiration
(in the presence of traheoezophageal fistula, infections (mumps, bronchiolitis,
pneumonia), inflammation, bronchospasm (asthma, bronchopulmonary dysplasia), as
well as foreign bodies.
2.
Restrictive violations
a) With the defeat of the parenchyma of the lungs.
Hypoplasia of lung, RDS, pneumothorax, hemorrhage, pulmonary edema and pleurisy.
b) With the defeat of the chest wall. Diaphragmatic
hernia, absence of ribs, hypoplasia and aplasia of the sternum, chest deformity
(rickets), abdominal distension, kyphoscoliosis, trauma restricted mobility of
the chest, severe myasthenia pseudoparalitic, muscular dystrophy, and obesity.
3. Diseases that lead to inadequate gas alveoli
and
capillaries exchanges
a) Diseases of the violations of diffusion. Diffuse type of
RF: lung edema, interstitial fibrosis, collagenosis, pneumonia
(Pneumocystis carinii), desquamative interstitial pneumonia.
b) Diseases due to inhibition of the respiratory center (Ventilation
type of RF). Traumatic brain injury, CNS infection, overdose of
sedatives; severe asphyxia and tetanus.
4. Other
situations that contribute to the development of the
acute respiratory distress
a) An increase in hydrostatic pressure.
b) Congestive heart failure.
c) The excess of fluid injected.
d) Intestinal obstruction.
e) Chronic broncho-pulmonary diseases
Etiologic classification of respiratory
insufficiency
1. RF related to the obstruction of respiratory
tracts (larynx-, bronchiolo-, bronchospasm, foreing body);
2. RF as a result of violation of diffusion of
gases through an alveolar-capillary membrane (pneumonias, chronic diseases of
lungs);
3. RF related to the damage of
respiratory system (trauma of thorax, pneumo- thorax);
4. RF of central genesis - arises up at the damage of
cerebrum (edema of brain, meningitis, cranial-cerebral trauma);
5. RF conditioned by violation of neuro-muscular
conductivity (poliomyelitis, myasthenia)
Clinic of respiratory insufficiency
1. Disturbances of function of the external breathing: shortness of
breath, difficulty of breathing, prolonged exhalation, participation
of auxiliary muscles, nod motions by a head, blowing of nostrils,
violation of rhythm of breathing (bradypnoe,
pathological type of breathing);
2. Signs
of hypercapnia, hypoxia: tachycardia, decreased arterial pressure, pallor of
skin, acrocyanosis, cyanosys, excitation or oppression of child;
3. Signs of tissue hypoxia: pallor -gray color of skin, bradycardia,
decreased arterial pressure and comma.
Clinical manifestations are divided into 3 groups.
1. Pulmonary symptoms
a) In infants and children with acute
respiratory failure - tachypnea, violations of the depth and rhythm of
respiratory movements, retraction of the intercostal spaces, the expansion of nostrils,
cyanosis, sweating.
b) possible shortness of breath and wheezing.
2. Neurological symptoms.
As a result of increased sensitivity of the
brain to hypoxemia there is developing headache, anxiety, irritability,
convulsions, and sometimes coma.
3. Symptoms of the cardiovascular system.
There
are bradycardia and hypotension. Severe and /or prolonged
respiratory failure can lead to heart failure and pulmonary edema.
Clinical classification of respiratory insufficiency
I stage: the shortness of breath in rest is
absent, perioral cyanosys, which increases at loading, PS: BR – 3,5-2,5: 1;
РаО2 – 80-65 mm
Hg
The ІІ stage: is the shortness of breath in rests,
perioral cyanosys, acrocyanosis permanent, participation of auxiliary
musculature in the act of breathing, PS: BR – 2-1,5: 1
РаО2 – 64-51mmHg
The ІІІ stage: is the
expressed shortness of breath in rest, the unrhythmical breathing (paradoxical
breathing), generalized cyanosys is permanent, does not disappear at breathing
by oxygen;
РаО2 – 50 and ¯
Respiratory failure in
acute pneumonia is 3 degrees.
At I degree respiratory insufficiency is compensated
by hyperventilation, there are no breathing disorders. At II degree there are
the clinical and laboratory signs of disorders of external respiration,
hemodynamics, but they are subcompensated. At III degree decompensation is
diagnosed, both external and internal respiration.
Spirography determines the speed and volume of breath
Clinical features of RDS in newborn
1.Tachypnoe (BR > 60), bradypnoe (BR <35);
2. Cyanosys;
3. Retractions (drawing in of pliable places of chest);
4. Blowing of wings of nose;
5. Grants (expiration moan);
6. Disturbance of rhythm or breathing;
7. Reduced activity.
Treatment of respiratory
failure
The treatment depends on the leading
pathological process, as well as the degree of hypoxemia, pCO2 and
pH. For the recovery there is necessary to liquidate respiratory failure
(removal of foreign body, the causes of the collapse of the lung: pneumothorax,
lobar emphysema, diaphragmatic hernia).
1. Oxygenation should begin only
after the removal of the contents of the airways and should be performed using
mixtures containing a minimum amount of oxygen that allows to maintain an
adequate level of arterial pO2 (> 60 mmHg). The use of excessive
concentrations of O2, may provoke pulmonary edema, atelectasis, or
lead to retinopathy in preterm infants. If resistant to treatment forms of
hypoxemia are present it needs intubation for ensuring long-term positive
pressure in the lungs.
2. Liquidation of the disorders in the lungs involves
the removal of bronchial secretion, the appointment of bronchodilators,
intubation, or connecting to a respiration apparatus.
a) Endotracheal or nasotraheal intubation is
enough to eliminate
obstruction
of the upper respiratory tract.
The correct location of
the tube should be monitored auscultation
or
X-ray.
b) Increasing the humidity of air
reduces the viscosity of bronchial
secretion.
3. Intubation and ventilation with positive
pressure is needed in patients
with elevated values of pCO2,
accompanied by respiratory acidosis.
Referens:
A - Basic:
1. Pediatrics. Textbook. / O. V. Tiazhka, T. V. Pochinok, A. N. Antoshkina et al. / edited
by O. Tiazhka – Vinnytsia : Nova Knyha Publishers, 2011 – 584 pp. : il.
2. ISBN 978-966-382-355-3Nelson Textbook
of Pediatrics, 19th Edition Kliegman, Behrman. Published by Jenson & Stanton, 2011, 2608.
ISBN: 978-080-892-420-3.
3. Illustrated Textbook of Paediatrics, 4th Edition. Published by Lissauer & Clayden, 2012, 552 p. ISBN:
978-072-343-566-2.
4. Denial Bernstein. Pediatrics for medical Students. – Second edition, 2012. – 650 p.
B - Additional:
1.http://intranet.tdmu.edu.ua/data/kafedra/internal/pediatria2/classes_stud/шпитальна%20педіатрія/6%20курс/English/Theme%2001%20Differential%20diagnosis%20of%20pneumonia%20in%20children.htm
2. http://www.merckmanuals.com/professional/index.html
3. Lichtenstein, et al. Pediatric
Pneumonia. Emergency medicine clinics of north America. 2010.
4. Barson. Clinical manifestations and diagnosis of community-aquired pneumonia in children.
UpToDate.com., 2009.
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