Methodological instruction
to practical lesson of nurse-bachelour students
LESSON № 4
Theme 1. Main mechanisms of external breathing disorder
Theme 2. Hypoxia
Aim: To be able to analyse violation of the external breathing as display of pulmonary disease and pathology other organs and systems. To be able to differentiate the types of gipoksiy and account for the mechanisms of basic compensate reactions.
Professional motivation
The disorder of external breath arise for want of operation of the various factors of the external and internal environment, however all of them on the mechanism of development are united in three groups - ventilating, diffusing and perfusing. Most seriosly by manifestation of disorder of external breath the respiratory unsufficiency is, as a result of which the gas structure of blood is changed and arises dispnea. On character of dispnea it is possible to make submission about the reason of a pathology. In particular, the deep and often breath arises for want of intimately – cardiac vascular of unsufficiency and anemias, deep and rare - for want of stenosis of respiratory paths, often and surface - for want of inflammation or edema easy.
Rather frequently respiratory unsufficiency arises for want of disorder regulation of influences on the part of respiratory centre. Excitability of respiratory centre is reduced for want of damages of the central nervous system: a sclerosis, spasms of vessels of a brain, insults, squeezing of a brain by a tumour, toxicel operation on respiratory centre of somnolent and narcotic preparations. The periodic breath, which for want of it arises, testifies to an oppression of respiratory centre. The breath of a type Cheyne-Stokes’ is more often observed for want of functional changes, and breath of a type Biott - for want of organic damages of a brain. From peripheral mechanisms primary significance have the violations of adequate reduction of respiratory muscles.
The problem of an oxygen deficiency invokes practical concern in clinic of internal illnesses (preventive maintenance and treatment of a myocardial infarction, diseases of the system of breathing, anemias), in neurologic clinic (preventive maintenance and treatment of ischemic damages of the brain), in surgical clinic (treatment obliteric endarteriitis, operations on life important organs), in obstetric practice (strife with a hypoxia of a fetus and neonatal). Professional selection of high-resistant to hypoxia people, and also acclimatization to an oxygen depletion has become a relevant problem of medicine.
1. Program of independent students prepare to lesson
Theme №1 practical lesson
1. Determination of concept of insufficiency of the external breathing, criteria, principles of classification
2. Extra pulmonary and pulmonary violations of alveolar ventilation: central, nerval-muscular, thoracodiaphragmatic, diminishing of communicating of airways, elastic properties of pulmonary tissue, amount of functioning alveoli
3. Mechanisms of violation of alveolar ventilation: dysregulatory, restrictive, obstructive
4. Reasons and mechanisms of gases diffusion violations in lungs
5. Violation of pulmonary circulation of blood
6. Violation of general and regional ventilation- perfusion relations in lungs
7. Changes of indexes of gas composition of blood and acid-basic state at the different types of respiratory insufficiency, their value for an organism
8. Pathogenesis of basic clinical signs of external breathing insufficiency
9. Shortness of breath: types, reasons, mechanisms of origin and development
10. Asphyxia, reasons of origin and mechanisms of development, stage of a asphyxia
11. Violations of non-respiratory functions of lungs, their influence on hemodynamics and hemostasis
12. Pathological breathing. Types of the periodic and terminal breathing
13. Kinds of respiratory unsufficiency: acute unsufficiency, chronic unsufficiency, obstructive unsufficiency, restrective unsufficiency, alveolar-respiratory unsufficiency
14. Disorder of central regulation of breath: Bradypnoea. Hyperpnoe. Polypnoe. Apnoe. Periodic breath. Terminal breath. Dispnoe.
Theme №2 practical lesson
1. Classification of hypoxia, definition of the notion “hypoxia”
2. Hypoxic hypoxia
3. Hemic hypoxia
4. Hemodinamic (circulative) hypoxia
5. Hystotoxic (tissue) hypoxia
6. Respiratory indexes of blood for hypoxias
7. Disorder of metabolism at hypoxia: carbohydrate, lipid, protein, and ion
8. Damage of organs for a hypoxia: damage of a nervous system, damage of the myocardium
9. Compensating reactions for a hypoxia: respiratory response, haemodynamic reactions, haemic reactionsm, tissues reactions
10. Acclimatization to a hypoxia.
2. Examples of the tests and real-life tasks
Theme № 1 practical lesson
Tesks (choose a right answer).
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Test 1. |
In the tourists, which rised on height 3000 m, the breath has become often and deep. These changes are a consequence of stimullation |
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А. Chemoreceptors of a carotid sine В. Mechanical receptors of pulmonary alveoles С. Baroreceptors of arc aorta D. Neurons of cortex brain Е. Myocytes of respiratory muscles |
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Test 2. |
At the patient is diagnosed croupous pneumonia. For this disease is characterized |
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А. Often deep breath В. Often surface breath С. Infrequent deep breath D. Cheyne-Stokes’ breath Е. Kussmaul’s breathing |
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Test 3. |
In the member of high-mountainous expedition at the height of 6 km has arisen vertigo, the sharp weakness has appeared. The climber has lost consciousness, the breath has stoped. These disorders have arisen in consequence |
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А. Insufficient of entering О2 in an organism В. Insufficient of utilization О2 by tissues С. Insufficient release of О2 oxyhemoglobin D. Excessive washout СО2 from an organism Е. Insufficient of derivation СО2 in tissues |
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Test 4. |
In the patient wich bronchial asthma after walk in park has arisen an attack dispnoe. The disorders of breath are conditioned by primary disorder |
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А. Excitability of respiratory centre В. Function of respiratory muscles С. Mobility of chest D. Perfusion of pulmonary tissue Е. Ventilating ability of the alveols |
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Test 5. |
In the child suffering bronchial asthma after transferred pneumonia has arisen heavy asthmatical an attack, that has resulted in development of acute respiratory unsufficiency. This complication is conditioned by |
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А. Deterioration of blood supply pulmonary tissue В. Decreasing of volume alveolar ventilation С. Difficulty of diffusion of gases in lung D. Increasing of dead space of lung Е. Blending of arterial and venous of blood |
Real-life tasks
Task 1
In one of the members of high-mountainous expedition the erose increasing and deepening of breath has occured which was replaced by a sudden oppression it and loss of consciousness.
1. Explain the mechanism of increasing and deepening of breath for want of rise on height.
2. Why stimulation of breath was replaced it by an oppression?
3. How the acsd-base balance in the climber was changed which has suffered?
4. What for him is better - inhalation of pure oxygen or carbogen?
Task 2
In the patient, which was on surgical table under narcosis, the sharp oppression of breath has occured. The pulse has become rare and weak. Has appeared cyanosis. The emergency measures accepted by the anaesthesiologist, liquidated these disorders.
1. What can be connected the oppression of breath with ?
2. How, on yours opinion, the contents of oxygen and carbonic acid in arterial of blood was changed in the patient?
3. Explain appearance of the cyanosis.
4. How are you evaluate changes of the pulse in this case?
Theme 2 practical lesson
Tests (choose a right answer).
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Test 1. |
Patient with myocardial infarction the tags of a hypoxia - dyspnea, tachycardia, paleness of dermal covers, and cyanosis of visible mucous covers have appeared. The development of a hypoxia for him is connected with |
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A. Decreasing of quantity of erythrocytes B. Decreasing a haemoglobin content C. Decreasing of speed of blood flow D. Poor oxygenation of blood E. Complicated dissociation of oxyhemoglobin |
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Test 2. |
Ambulance delivers to the hospital unconscious person poisoned with a carbon monoxide. The hypoxia is conditioned by accumulation in a blood |
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A. Methemoglobin B. Carbhemohlobin C. Oxyhemoglobin D. Desoxyhemohlobin E. Carboxyhemoglobin |
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Test 3. |
One of the climbers during ascent on an altitude subitaneously has lost consciousness. It happened owing to |
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A. Reduction of pressure of oxygen in blood B. Reduction of pressure of carbonic acid in blood C. Reduction of oxygen capacity of blood D. Inactivation of enzymes of histic breathing E. Deboosting of dissociation of oxyhemoglobin |
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Test 4. |
After a massive hemorrhage the patient had hypovolemic shock with development of a steep hypoxia. Its consequences most essentially will be mirrored in activity of |
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A. Lungs B. Kidney C. Spleen D. Brain E. Heart |
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Test 5. |
During auscultation the patient was asked to breathe deeply. After 10 respiratory motions he has experienced a vertigo. It was caused by |
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A. Decreasing quantity of erythrocytes in blood B. Decrease of concentration of a haemoglobin in blood C. Disturbance of diffusion of gases in lungs D. Reduction of concentration of carbonic acid in blood E. Deterioration of a blood supply of a pulmonary tissue |
Real-life tasks
Task 1
At a patient with the nonclosure of the Botalovogo channel the such respiratory indexes of arterial blood are certain: oxygen capacity - 20 by volume %, maintenance of oxygen - 15,6 by volume %, saturation of haemoglobin by oxygen - 82 %, pressure of oxygen in an arterial blood - 76 mm Hg.
1. How do you estimate material well-being of organism of patient with oxygen?
2. If is she insufficient, as is this being named?
3. What mechanism of his development?
4. What did you recommend for correction of oxygen balance in this case?
Task 2
A patient was hospitalized in the surgical separation concerning the gastric bleeding. Skin covers are pale. A pulse and breathing rate increased. Amount of red corpuscles - 3,12∙1012/l, maintenance of haemoglobin - 82 g/l.
1. Is there hypoxia at a patient? Ground your answer.
2. If yes, what type she belongs to?
3. What mechanism of its development?
4. Whether will tension of oxygen and maintenance of oxigemoglobin be here changed in an arterial blood?
5. What measures is it necessary to take for the removal of this hypoxia?
3. Right answers for tests and real-life tasks:
Theme № 1 practical lesson
Tests: 1 – A, 2 – B, 3 – D, 4 – Е, 5 – В.
Task 1
1. The low partial pressure of oxygen in atmospheric air on mountain is the reason hypoxia. Hypoxic blood irritates chemoreceptors of carotid sinus and aortic zones. From here stimulating impulses enter in respiratory centre in result the breath becomes often and deep.
2. Strengthened breath bents for oneself washout from blood of carbonic acid, which is physiological stimulus of respiratory centre. As a result of it the oppression of breath occurs.
3. Arises gaseus alkalosis as result of the strengthened separation of carbonic acid through lung.
4. It is better - carbogen (О2 - 95 %, СО2 - 5 %).
Task 2
1. Overdosage of narcotic substance reduces exitability of respiratory centre, as results in an oppression of breath.
2. The contents of oxygen decreases, and carbonic acid is increased.
3. It is connected with accumulation desoxyhemoglobin, which gives to tissues blue .
4. The rare and weak pulse has arisen as a result of an oppression of activity intimately – cardiovascular centre.
Theme №2 practical lesson
Tests: 1 – C, 2 – E, 3 – B, 4 – D, 5 – D.
Task 1
1. Outgoing from indexes of a blood, it is possible to approve, that the organism of the patient is supplied with oxygen insufficiently. He has the decreased contents of oxygen in a blood (norm - 19,0 volumetric %), contents of an oxyhemoglobin (norm - 95 %) and pressure of oxygen in an arterial blood (norm- about 100 mm Hg).
2. The condition of poor supply of tissues of an organism with oxygen, appropriate to the patient is called hypoxia (oxygen deficiency). Detected changes of respiratory indexes of a blood are characteristic for hypoxic hypoxia.
3. The hypoxia of the patient is conditioned by the mixing of saturated oxygen of an arterial blood and oxygen-deficient venous one. In the total the general contents of oxygen in a blood is lowered.
4. For correction of oxygen balance for given patient it is possible to recommend inhalation of CO2 and operational elimination of an arterial venous anastomosis.
Task 2
1. It is possible to approve about availability of a hypoxia of the patient on the basis of an analysis blood (decreasing of quantity of erythrocytes and haemoglobin content).
2. This hypoxia falls into haemic type.
3. Reduction of oxygen capacity of blood.
4. If there are no concomitant diseases of organs of cardiovascular and respiratory systems, the pressure of oxygen and contents of an oxyhemoglobin in an arterial blood will be maximum. An acceleration of pulse and breathing promotes this.
5. Adequate measure of elimination of a hypoxia for given patient is considered to be blood or red cell mass transfusion and assigning of medical agents, which stimulate hemopoesis.
4. Informational sources
1. Bondarenko Yu.I., Khara M.R., Fayfura V.V., Poticha N.Ya. Pathological physiology. – Ternopil TSMU: Ukrmedkniha, 2006.
5. Students’ practical activities
Тheme № 1 practical lesson.
Work 1. Change of breathing due to lactic acid
Rat to weigh before fixing and narcotize by intramuscular introduction of nembutal from account 0,6 ml 0,5 % of a solution on 100 g of weight. To cut a on middle of the neck and to move grooved the probe under jugular vein. In the vein to enter injectionsl needle. To take writing initial pneumogramme on drum kymograph. To enter in the vein 0,5 ml 5 % solution of lactic acid. To monitor changes of breath. For want of effect experience to repeat.
Explain the mechanism of changes of breath of rat.
Work 2. The decision of real-life situations of pikflowmetry.
Theme №2 practical lesson
Work 3. To consider studying charts:
1. Changes of breathing and arterial pressure during a sharp asphyxia
2. Action of the low atmospheric pressure on an organism
Work 4. Recognition of hypoxia the types
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Hypoxia |
Oxygen capacity % |
Arterial blood |
Venous blood |
Arterial-venous difference of O2 concentration |
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O2 Content % |
O2 Saturation |
O2 Pressure mm Hg |
O2 Content % |
O2 Saturation |
O2 Pressure mm Hg |
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Norm |
20 |
19 |
95 |
100 |
14,8 |
74 |
41 |
4,2 |
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а) |
10 |
9,5 |
95 |
100 |
5,3 |
53 |
28 |
4,2 |
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b) |
20 |
19 |
95 |
100 |
10,6 |
53 |
28 |
8,4 |
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c) |
20 |
19 |
95 |
100 |
18 |
90 |
80 |
1,0 |
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d) |
20 |
14,8 |
74 |
45 |
10,6 |
53 |
21 |
4,2 |
6. Discussion of theoretical questions and practical work results
1. Reasons of violations of the external breathing
2. Forms of respiratory insufficiency
3. Types of shortnesses of breath, their pathogenesis
4. Types of the periodic breathing, mechanism of their development
5. Types of the terminal breathing, mechanism of their development
6. Stages of asphyxia, change of breathing at an asphyxia
7. Determination and classification of hypoxia
8. Type of hypoxia from data of gas composition of blood
9. Mechanisms of basic compensate reactions at hypoxia
10. Metabolic disturbance at hypoxia
7. Final level of knowledge and abilities (control tasks)
8. Student should know:
1. Reasons of violations of the external breathing
2. Forms of respiratory insufficiency
3. Types of shortnesses of breath
4. Types of the periodic breathing
5. Types of the terminal breathing
6. Stages of asphyxia
7. Determination of hypoxia
8. Classification of hypoxia
9. Metabolic disturbance at hypoxia
10. Damage of heart and brain at hypoxia
11. Basic groups of compensate reactions at hypoxia
9. A student must be able:
1. To account for the role of violations of ventilation, diffusion and perfusion in development of pulmonary insufficiency
2. To account for the mechanisms of origin of pulmonary insufficiency at emphysema and bronchial asthma
3. To account for pathogenesis of shortnesses of breathing
4. To account for the mechanisms of origin of the periodic and terminal breathing
5. To describe the changes of breathing at an asphyxia
6. To expose the mechanisms of basic compensate reactions at hypoxia
7. To define the type of hypoxia from data of gas composition of blood
8. To define the type of violation of the external breathing from data of spirogramm
Methodological instruction made by prof. Yu.I. Bondarenko, as. prof. N.Ya. Potikha.
The methodological instruction was discussed
and confirmed at the Department sitting
“29” of August, 2013. Minute № 2.