1. PHYSIOLOGY OF LUNG IN HEALTH
AND ILLNESS
Presented by: Ligi Xavier
Second year MSc nursing
Govt. College Of Nursing, Kottayam

3. PHYSIOLOGY OF RESPIRATION
 inspiration- breathing in..
 principle inspiratory muscles- the diaphragm &
external intercostals.
 stimulation of diaphragm by the phrenic nerve
diaphragm becomes tenses & flattens
this enlarges the thoracic cavity& reduces its
internal pressure

4. this force air in to the lungs
 other muscles also help-the scalenes fix the first
pair of ribs while the external intercostal muscle lift
the remaining ribs like bucket handles, making
them swing up and out- this also forces air into the
lungs.
 deep inspiration – is aided by the pectoralis minor,
sternocleidomastoid, and erector spinae muscles.

5.  expiration- passive process . It is achieved by the
elasticity of the lungs and the thoracic cage- i.e.,
the tendency to return to their original dimensions
when released from tension.

8. LUNG VOLUMES AND CAPACITIES
 Lung volumes and lung capacities refer to
the volume of air associated with different phases
of the respiratory cycle. Lung volumes are directly
measured; Lung capacities are inferred from lung
volumes.
 The healthy adult averages 12 respirations a
minute and moves about 6 liters of air into and out
of the lungs while at rest.

9. CNTD..
 tidal volume- the total amount of air moves into and
out of the airways with each inspiration and
expiration during normal quiet breathing.
[vT][500ml]
 About 150 mL of it (typically 1 mL per pound of
body weight) fills the conducting division of the
airway. Since this air cannot exchange gases with
the blood, it is called dead air, and the conducting
division is called the anatomic dead space.

10.  Physiologic (total) dead space- is the sum of
anatomic dead space and any pathological alveolar
dead space that may exist. In healthy people, few
alveoli are nonfunctional, and the anatomic and
physiologic dead spaces are identical.
 The total volume of air taken in during 1 minute is
called the minute volume of respiration [MVR] or
minute ventilation. It is calculated by multiplying
the tidal volume by the normal breathing rate per
minute.[500×12= 6000ml/mt].

11.  The alveolar ventilation rate [AVR] is the volume
of air per minute that reaches the alveoli.


12.  Inspiratory reserve volume (IRV)[3,000 mL]:-
Amount of air in excess of tidal inspiration that can
be inhaled with maximum effort.
 Expiratory reserve volume (ERV)[1,200 mL]:-
Amount of air in excess of tidal expiration that can
be exhaled with maximum effort.
 Residual volume (RV)[1,300 mL]:-Amount of air
remaining in the lungs after maximum expiration;
keeps alveoli inflated between breaths and mixes
with fresh air on next inspiration.

13.  Vital capacity (VC)[4,700 mL]:-Amount of air that
can be exhaled with maximum effort after maximum
inspiration (TV + IRV + ERV); used to assess
strength of thoracic muscles as well as pulmonary
function.
 Inspiratory capacity (IC)[3,500 mL]:-Maximum
amount of air that can be inhaled after a normal
tidal expiration (TV + IRV).
 Functional residual capacity (FRC)[2,500 mL]:-
Amount of air remaining in the lungs after a normal
tidal expiration (RV + ERV)

14.  Total lung capacity (TLC)[6,000 mL]:-Maximum
amount of air the lungs can contain (RV + VC).

15. PULMONARY FUNCTION TESTS
 Pulmonary function tests
 Pulmonary function can be measured by having a
subject breathe into a device called a spirometer, which
recaptures the expired breath and records such
variables as the rate and depth of breathing, speed of
expiration, and rate of oxygen consumption. Four
measurements are called respiratory volumes: tidal
volume, inspiratory reserve volume, expiratory
reserve volume, and residual volume. Four others,
called respiratory capacities, are obtained by adding
two or more of the respiratory volumes: vital capacity,
inspiratory capacity, functional residual capacity,
and total lung capacity.

16. SPIROGRAMS AND FLOW VOLUME CURVES


17. ALVEOLAR SURFACE TENSION
 During breathing, the surface tension must be
overcome to expand the lungs during each
inspiration. It is also the major component of lung
elastic recoil, which acts to decrease the size of
alveoli during expiration.The surface tension of
alveolar fluid is not as great as that of pure water
due to the presence of a detergent-like substance
called surfactant, produced by type 2 alveolar cells.
Surfactant is a complex mixture of phospholipids
and lipoproteins. It lowers the surface tension of
alveolar fluid and thus reduces the tendency of
alveoli to collapse completely.

18. LUNG COMPLIANCE
 It is the measure of the stretchability of lungs
defined as the ratio of change in lung volumes
to change in trans pulmonary pressure.lung
resisting expansion at high volume.
 C= V
 P
 Normal value=200ml/cm of H2o

19. COMPLIANCE LOOP
 it is hysteresis loop in which the inspiratory
compliance is less than that of expiratory
compliance and loop is coming back to the
same point of origin as we trace the compliance
of full one respiration.

20. RESISTANCE TO AIRFLOW
 Flow = change in pressure/resistance (F = AP/R).
 Factors affecting
Pulmonary compliance
Diameter of the bronchiloes

21. VENTILATION PERFUSION RATIO
 VA almost equal to 0.8. mismatch usually seen
in pulmonary embolism.

22. PATTERNS OF BREATHING
 Apnea -Temporary cessation of breathing (one or
more skipped breaths).
 Dyspnea-Labored, gasping breathing; shortness of
breath.
 Eupnoea-Normal, relaxed, quiet breathing; typically
500 mL/breath, 12 to 15 breaths/min.
 Hyperpnea -Increased rate and depth of breathing
in response to exercise, pain, or other conditions.

23.  Hyperventilation-Increased pulmonary ventilation in
excess of metabolic demand, frequently associated
with anxiety; expels C02 faster than it is produced,
thus lowering the blood C02 concentration and
raising the pH.
 Hypoventilation-Reduced pulmonary ventilation;
leads to an increase in blood C02 concentration if
ventilation is insufficient to expel C02 as fast as it is
produced.
 Kussmaul-Deep, rapid breathing often induced by
acidosis, as in diabetes mellitus.

24.  Orthopnea -Dyspnea that occurs when a person is
lying down.
 Respiratory arrest-Permanent cessation of
breathing (unless there is medical intervention).
 Tachypnea -Accelerated respiration .

25. GAS EXCHANGE & TRANSPORT
 External[pulmonary] respiration-it
is the exchange of O2 and CO2 between air in the
alveoli of the lungs and blood in pulmonary
capillaries. It results in the conversion of
deoxygenated blood coming from heart to
oxygenated blood.
 factors that affect the efficiency of alveolar gas
exchange:-
 concentration gradient of gases[ie, po2 & pco2]
 Solubility of the gases
 Membrane area
 Ventilation-perfusion coupling.

27. INTERNAL RESPIRATION
 exchange of oxygen and carbon dioxide between
tissue blood capillaries and tissue cells called
internal[tissue]respiration.it results in the conversion
of oxygenated blood into deoxygenated blood.
 Oxygenated blood entering tissue capillaries has a
pO2 of 100 mm Hg, where as tissue cells have an
average Po2 of 40 mm of Hg. Because of this
difference , oxygen diffuses from the oxygenated
blood through interstitial fluid and into tissue cells
until the pO2 in the blood decreases to 40 mm of
Hg

28.  While oxygen diffuses from the tissue blood
capillaries to tissue cells, carbon dioxide diffuses in
the opposite direction.

29. GAS TRANSPORT
 1. oxygen-
 The concentration of oxygen in arterial blood, by volume, is about 20
mL/dL. About 98.5% of this is bound to hemoglobin and 1.5% is
dissolved in the blood plasma.

30. OXYGEN DISSOCIATION CURVE

31. 2. CARBON DIOXIDE-
 a] About 90% of the CO2 is hydrated (reacts with water) to form carbonic
acid, which then dissociates into bicarbonate and hydrogen ions.
 B] About 5% binds to the amino groups of plasma proteins and
hemoglobin to form carbamino compounds—chiefly,
carbaminohemoglobin (HbCO2).
 c] The remaining 5% of the CO2 is carried in the blood as dissolved gas.

32. ARTERIAL BLOOD GAS ANALYSIS
 An arterial blood gas (ABG) test measures the
acidity (pH) and the levels of oxygen and carbon
dioxide in the blood from an artery. This test is used
to check how well lungs are able to move oxygen
into the blood and remove carbon dioxide from the
blood.

33. ABG VALUES
 Partial pressure of oxygen (PaO2):Greater than
80 mm Hg (greater than 10.6 kPa)
 Partial pressure of carbon dioxide (PaCO2):35-
45 mm Hg (4.6-5.9 kPa)
 pH:7.35-7.45
 Bicarbonate (HCO3):23-30 mEq/L (23-30 mmol/L)
 Oxygen content (O2CT):15-22 mL per 100 mL of
blood (6.6-9.7 mmol/L)
 Oxygen saturation (O2Sat):95%-100% (0.95-
1.00)

34. PULSE OXIMETRY
 A non invasive technolgy to monitor oxygen
saturation of the haemoglobin

35. wavelength
Extinction
coefficient
660nm 940nm
MetHb
Oxy Hb
Deoxy
Hb
COHB

36. DESIGN OF PULSEOXIMETER
 2 Wavelengths-
660nm [red] & 940nm[infra red]
The ratio of absorbencies at these two wavelengths is
calibrated empirically against direct measurements of arterial
blood oxygen saturation (SaO2) in volunteers, and the resulting
calibration algorithm is stored in a digital microprocessor within
the pulse oximeter.
 Led & photodetector
 Newer types of LED is based on aluminium gallium arsenide
system
 Signal processed in the micro processor
 Senses only the pulsatile flow

37.  PaO2 [mmHg] SaO2 [%]
 Normal 97 to ≥80 97 to ≥95
 Hypoxia < 80 < 95
 Mild 60-79 90-94
 Moderate 40 – 59 75 – 89
 Severe <40 < 75

38. USES OF PULSEOXIMETRY
 Monitoring oxygenation
During anaesthesia
in ICU, PACU
during transport
Monitoring oxygen therapy
 Assesment of perfusion
Monitoring vascular volume
 Sleep studies -24-h ambulatory recordings of SpO2 is
useful for screening for daytime sleep sequelae associated
with the potential risk of this pathology in OSAS during
social activities.

39. DISADVANTAGES
 Decrease in PAO2 before fall in SPO2
 Due to the shape of ODC
 SPO2 94% - PAO2 75%

40. ADVANTAGES
 Simple to use
 Non-invasive
 Require no warm up time
 Especially in African &Asian patients
 Cost-effectiveness over ABG

41. CONTROL OF RESPIRATION
 There are four main centers in the brain to regulate
the respiration:
 1. Inspiratory center
 2. Expiratory center
 3. Pneumotaxic center
 4. Apneustic center. The first two centers are
present on the medulla oblongata whereas the last
two centers on the Pons region of brain.

42. DISEASES THAT IMPAIR GAS EXCHANGE
 Asthma
 Emphysema
 Occupational Respiratory Disorders
 Tuberculosis
 atelectasis.
 Adult respiratory distress syndrome (ARDS
 Bronchitis
 Cystic fibrosis
 Lung cancer

43.  Nervous System disorders
Sudden infant death syndrome (SIDS)
Paralysis of the respiratory muscles
Diseases of the Upper Respiratory Tract
Strep throat
Diphtheria
Diseases of the Lower Respiratory Tract
Laryngitis, Whooping cough (pertussis)
pneumonia,influenza

44. INTERCOSTAL CHEST DRAINAGE
 is a flexible plastic tube that is inserted through the
chest wall and into the pleural space or
mediastinum It is used to remove air or fluid
(pleural effusion, blood, chyle), or pus (empyema)
from the intrathoracic space. It is also known as a
Bülau drain

45. INDICATIONS
 Left-sided pneumothorax (right side of image)
on CT scan of the chest with chest tube in
place.
 Pneumothorax: accumulation of air or gas in
the pleural space
 Pleural effusion: accumulation of fluid in the
pleural space
Chylothorax: a collection of lymphatic fluid in the pleural
space
Empyema: a pyogenic infection of the pleural space
Hemothorax: accumulation of blood in the pleural space
Hydrothorax: accumulation of serous fluid in the pleural space
Postoperative: for example, thoracotomy, oesophagectomy,
cardiac surgery

46. TECHNIQUE
 Tube thoracostomy
 The free end of the tube is usually attached to an
underwater seal, below the level of the chest. This
allows the air or fluid to escape from the pleural space,
and prevents anything returning to the chest.
Alternatively, the tube can be attached to a flutter valve.
This allows patients with pneumothorax to remain more
mobile.
 British Thoracic Society recommends the tube is
inserted in an area described as the "safe zone", a
region bordered by: the lateral border of pectoralis
major, a horizontal line inferior to the axilla, the anterior
border of latissimus dorsi and a horizontal line superior
to the nipple. More specifically, the tube is inserted into
the 5th intercostal space slightly anterior to the mid
axillary line.

47. POSTOPERATIVE DRAINAGE
 The placement technique for postoperative drainage
(e.g. cardiac surgery) differs from the technique used for
emergent situations. At the completion of open cardiac
procedures, chest tubes are placed through separate
stab incisions, typically near the inferior aspect of the
sternotomy incision. In some instances multiple drains
may be used to evacuate the mediastinal, pericardial,
and pleural spaces. The drainage holes are place inside
the patient, and the chest tube is passed out through the
incision. Once the tube is in place, it is sutured to the
skin to prevent movement. The chest tube is then
connected to the drainage canister using additional
tubing and connectors, and connected to a suction
source, typically regulated to -20cm of water.

48. NURSING MANAGEMENT
 Chest drains should not be clamped
 Start of shift checks
Patient assessment
Chest drain assessment
Other considerations e.g physiotherapy referral
Patient Assessment
 HR, SaO2, BP, RR
 Routine vital signs:

49. Chest tubes are painful as the parietal pleura is very
sensitive. Patients require regular pain relief for comfort,
and to allow them to complete physiotherapy or mobilise
Pain assessment should be conducted frequently and
documented
Observe for signs of infection and inflammation and
document findings
Check dressing is clean and intact
Observe sutures remain intact & secure (particularly long
term drains where sutures may erode over time)

50. Never lift drain above chest level
The unit and all tubing should be below patients chest level to
facilitate drainage
Tubing should have no kinks or obstructions that may inhibit
drainage
 Ensure all connections between chest tubes
and drainage unit are tight and secure
Suction is not always required, and may lead to tissue trauma
and prolongation of an air leak in some patients
If suction is required orders should be written by medical staff
Wall suction should be set at >80mmHg or higher
Suction on the Drainage unit should be set to the prescribed
level

51. Milking of chest drains is only to be done with written
orders from medical staff. Milking drains creates a high
negative pressure that can cause pain, tissue trauma
and bleeding
Volume
Document hourly the amount of fluid in the drainage
chamber on the Fluid Balance Chart
 Calculate and document total hourly output if multiple drains
 Calculate and document cumulative total output
Notify medical staff if there is a sudden increase in
amount of drainage
 greater than 5mls/kg in 1 hour
 greater than 3mls/kg consistently for 3 hours

52. AIR LEAKAGE (BUBBLING)
An air leak will be characterised by intermittent bubbling
in the water seal chamber when the patient with a
pneumothorax exhales or coughs.
The severity of the leak will be indicated by numerical
grading on the UWSD (1-small leak 5-large leak)
Continuous bubbling of this chamber indicates large air
leak between the drain & the patient. Check drain for
disconnection, dislodgement and loose connection, and
assess patient condition. Notify medical staff
immediately if problem cannot be remedied.
Document on Fluid Balance Chart

53. OSCILLATION (SWING)
The water in the water seal chamber will rise and fall
(swing) with respirations. This will diminish as the
pneumothorax resolves.
Watch for unexpected cessation of swing as this may
indicate the tube is blocked or kinked.
Cardiac surgical patients may have some of their drains
in the mediastinum in which case there will be no swing
in the water seal chamber.
 Document on Fluid Balance Chart
 Patients who are ambulant post operatively will
have fewer complications and shorter lengths of
stay.

54. REMOVAL OF THE TUBE
 Clinical status is the best indicator of a reaccumulation of air or
fluid. CXR should be performed if patient condition deteriorates
 Monitor vital signs closely (HR, SaO2, RR and BP) on removal
and then every hour for 4 hours post removal, and then as per
clinical condition
 Document the removal of drain in progress notes and on
patient care record
 Remove sutures 5 days post drain removal
 Dressing to remain insitu for 24 hours post removal unless
dirty
 Complications post drain removal include pneumothorax,
bleeding and infection of the drain site

56. ASSESSMENT
 Client History
Subjective symptoms
 Dyspnea with ADLs?
 Childhood diseases
 Asthma, pneumonia, allergies, croup
 Adult illnesses
 Pneumonia, sinusitis, TB, HIV, emphysema, DM, HTN,
cardiac disease
 Vaccine history
 Flu, pneumonia, BCG

57. ASSESSMENT
 Client History
Surgeries of upper or lower respiratory tract
Injuries to upper or lower respiratory tract
Hospitalizations
Date of last
 CXR, PPD, PFT
Recent weight loss
Night sweats

58. PHYSICAL ASSESSMENT
 Auscultation
Upright first
Bare chest
Open mouth breathing
Full respiratory cycle
Observe for dizziness

59. PHYSICAL ASSESSMENT
 Lungs and Thorax
Inspection
Palpation
 Fremitus
 99
 Crepitus
 Bubble wrap
 Chest expansion
 Movement

60. PHYSICAL ASSESSMENT
 Lungs and Thorax
Percussion
 Pulmonary resonance
 Air, fluid, solid masses
 Intercostal spaces only
 Diagphragmatic excursion
Normal 1 -2 inches
Deep breath / percuss
No breath / percuss
Normally higher on the right (liver)

61. PHYSICAL ASSESSMENT
 Normal breath sounds
Bronchial, bronchovesicular, vesicular
Not heard peripherally
 Adventitious breath sounds
Additional sounds superimposed on normal sounds
Indicate pathology
Crackles, wheezes, rhonchi, pleural friction rub

62. PHYSICAL ASSESSMENT
 Skin and Mucous Membranes
Pallor, cyanosis, nail beds
 General Appearance
Muscle development, general body build
Muscles of neck, chest
 Endurance
How does the client move in 10 – 20 steps?
Speaking exertion

63. NURSING DIAGNOSES
 Ineffective breathing pattern related to:
increased rate and decreased depth of respirations
associated with fear and anxiety
decreased lung compliance (distensibility)
associated with pleural effusion and accumulation
of fluid in the pulmonary interstitium and alveoli
diminished lung/chest wall expansion associated
with weakness, decreased mobility, and pressure on
the diaphragm as a result of peritoneal fluid
accumulation (if present)
respiratory depressant and/or stimulant effects of
hypoxia, hypercapnia, and diminished cerebral
blood flow;

64.  ineffective airway clearance related to:
increased airway resistance associated with edema
of the bronchial mucosa and pressure on the
airways resulting from engorgement of the
pulmonary vessels
stasis of secretions associated with decreased
mobility and poor cough effort;
 impaired gas exchange related to:
impaired diffusion of gases associated with
accumulation of fluid in the pulmonary interstitium
and alveoli
decreased pulmonary tissue perfusion associated
with decreased cardiac output.