Respiratory Assessment
DR. MOHAMED SEYAM PHD. PT.
ASSISTANT PROFESSOR OF PHYSICAL THERAPY
INVESTIGATION
Arterial Blood Gas(ABG)
The body produces acids daily: - 15,000 mmol CO2 and - 50 -100 mEq
Nonvolatile acids (an acid produced from sources other than carbon dioxide).
The lungs and kidney attempt to maintain balance by eliminating CO2 by secretion
of H+ and HCO3 reabsorption.
The Components:
pH / PaCO2 / PaO2 / HCO3
Normal Arterial Values
pH
- 7.35 - 7.45
PaCO2
- 35-45 mmHg
PaO2
- 80-100 mmHg
HCO3
- 22-28 mEq/L
Respiratory Acidosis
pH,
CO2 ,
Ventilation
oCauses
1) CNS depression
2) Lung diseases like COPD/ARDS, Pneumothorax,
3) Diaphragmatic paralysis, Restrictive lung disease.
4) Musculoskeletal disorders(Myasthenia gravis, Guillain Barre syndrome)
Respiratory Alkalosis
pH,
CO2,
Ventilation
Causes
1) Intra cerebral hemorrhage (Head injury)
2) Anxiety – decrease lung compliance
3) Cirrhosis of the liver
4) Sepsis
5) Pulmonary Embolism
6) Pneumonia
7) Asthma
Metabolic Acidosis
pH,
HCO3
Causes
1. Lactic acidosis-is when lactic acid builds ups in the bloodstream faster than it
can be removed.
2. Keto acidosis ( Associated with Diabetes) It occurs when the body cannot use
sugar (glucose) as a fuel source because there is no insulin or not enough
insulin. By products of fat breakdown, called ketones, build up in the body.
3. Renal failure
4. Chronic diarrhea
Metabolic Alkalosis
pH,
HCO3
Causes
1) Vomiting
2) Diuretics
3)
- Diuretics cause the kidneys to remove
more sodium and water from the body
4) Hypokalemia - A drop in potassium level.
5) Renal Failure
Pulmonary Function test
Spirometry is a medical test that measures the volume of air an individual inhales or
exhales as a function of time.
Pulmonary function studies are commonly subdivided into the following
1. Lung volumes and capacities
2. Forced expiratory flow rate
3. Pulmonary diffusion capacity measurements
USES OF PULMONARY FUNCTION TEST
◦ To evaluate respiratory symptoms
To determine severity of impairment in patients with known respiratory disease
◦ To follow the course of disease in a patient, including the response to therapy
To assess preoperative risk for predicting postoperative respiratory complications
To screen for subclinical disease
Technique
Have patient seated comfortably
Closed-circuit technique
Place nose clip on
Have patient breathe on mouthpiece
Have patient take a deep breath as fast as possible
Blow out as hard as they can until you tell them to stop
Forced vital
capacity (FVC)
Total volume of air that can
be exhaled forcefully from
TLC
The majority of FVC can be
exhaled in <3 seconds in
normal people, but often is
much more prolonged in
obstructive diseases.
Measured in liters (L)
Forced vital capacity (FVC):
Interpretation of % predicted:
80-120%
Normal
70-79%
Mild reduction
50%-69%
Moderate reduction
<50%
Severe reduction
Forced expiratory volume in first second: (FEV1)
Volume of air forcefully expired from full inflation (TLC) in the first second
Measured in liters (L)
Normal people can exhale more than 75-80% of their FVC in the first second;
thus the FEV1/FVC can be utilized to characterize lung disease
Interpretation of % predicted:
> 75%
Normal
60%-75%
Mild obstruction
50-59%
Moderate obstruction
< 49%
Severe obstruction
FEV1/FVC ratio
Thus compares the amount of air exhaled in 1 second with the total amount
exhaled during an FVC maneuver.
FEV 1/FVC ratio should be 80% or greater.
FEV 1/FVC ratio is DECREASED in COPD
FEV 1/FVC ratio is NORMAL or INCREASED in Restrictive lung disorders
Flow volume
Loop
 The flow volume
loop is a graphical
illustration
maximum
expiratory and
inspiratory flowvolume curves
• Useful to help
characterize
disease states (e.g.
obstructive vs.
restrictive)
Obstructive Disorders
-Characterized by a
limitation of expiratory
airflow
Examples: asthma, COPD
-Decreased: FEV1, FEF25-75,
FEV1/FVC ratio (<0.8)
-Increased or Normal: TLC
Restrictive disorders
-Characterized by diminished lung
volume due to:
• Change in alteration in lung
parenchyma (interstitial lung disease)
• Disease of pleura, chest wall (e.g.
scoliosis), or neuromuscular apparatus
(e.g. muscular dystrophy)
FINDINGS
-Decreased TLC, FVC
-Normal or increased: FEV1/FVC ratio
Measurements of the Residual Volume
1. Closed Circuit
helium dilution test
2. Open circuit
nitrogen test
3. Body
Plethysmography
Chest Radiographs (chxR)
Chest radiographs provide a static view of the anatomy of the chest
and they may be used to screen for abnormalities.
Standard views:
1) Posterior anterior(PA):
Patient in the standing
position with the front of
the chest facing the film cassette.
2) Anteroposterior(AP)
OTHER VIEWS OF CHEST X RAY
3) lateral view : Taken at bedside
4)Decubitus view: To confirm the presence of an air-filled level in the
lungs /pleural effusion.
5) Lordotic view: Visualize the apical or middle lobes.
6)Oblique: To detect pleural thickening, evaluate carina, see heart and
great vessels.Position – standing diagonally
Steps for assessment of chest x-ray
Assess the technical quality
Evaluate the location of all catheters, tubes and support devices.
Assess cardio vascular system status
Check for abnormal parenchymal opacities
Evidence of barotrauma
Look for pleural effusions
Bones and soft tissues: Size, shape, symmetry of bony thorax, vertebral body faintly
visible
 Determine whether patient is rotated to either side (distance from medial end of clavicle
to spinous process)
 Width of intercostal space(↑space means ↑thoracic volume)
 Rounded, smooth sharply defined shadow of hemi diaphragms (Right side 1-2 cm higher
than left)
 Diaphragm elevated- if less than 9 ribs visible above the level of domes.
Diaphragm Depressed- if more than 10 ribs visible.
Costophrenic angles: where hemi diaphragm meet the chest wall at the lateral aspect.
Opacification of this angle – Pleural thickening/ Pleural
effusion
Cardio phrenic angle: Where hemi diaphragm meets the borders of the heart
Bronchography : It is an x-ray of the bronchus involving the use
of contrast. Evaluation of some congenital pulmonary anomalies.
Bronchoscopy : Permits direct visualization of inaccessible areas of bronchial tree.
It is indicated to assess for infection that cannot be evaluated from a sample or to
assess for malignancy.
Thank you