RESP 2: Lung Disease Diagnostics

different diagnostic tests for lung disease

Lung Function Tests

•Spirometry

•Peak flow meters

Chest x-rays

Ultrasounds

CT scans

What is a spirometry test?

-measures how far air moves in and out of the lungs

procedure for spirometry test

-patient takes a deep breath and blows as hard as possible into tube with a clip on nose

-technician monitors and encourages patient during test

-machine records resuls

In Spirometry: Healthy lung size and function is dependent on what 4 variables

•Age

•Sex

•Height

•Race

In Spirometry what are the 3 values?

•Forced vital capacity (FVC)

-total amount of air that can be expelled from full lungs

•Forced expiratory

volume in the first second (FEV1)

-the amount of air expelled during the first second of the spirometry maneuver

•FEV1/FVC ratio

-the fraction of air exhaled in the first second relative to the total volume exhaled

vital capacity

-a volume of a full breath exhaled in the patient's own time and not forced

practice question

1.The volume of air expired in the first second of exhalation

2.The unforced volume of full breath exhaled in the patient's own time

3.The total volume of air that can be forcibly exhaled in one breath

4.The fraction of air exhaled in the first second relative to the total volume

slide 11

Spirometry Reversibility test

-Determination of airflow limitation reversibility using drug administration

-Done to detect pts w/ reversible airway obstruction

-+ve if FEV1 changes by ~ 12% and FVC changes by ~200mL

-Larger doses of bronchodilators are administered

suggesed pattern of FEV1 and FVC values

look on slide 14

Limitations of spirometry

- Pt needs to show effort and cooperation

- Clinical context is important

- Normal values may not be reflective

asthma adults diagnoses values

Reduced FeV/FVC = <0.75-0.8

AND

Inncrease in FEV after a bronchodilator or after course of controller therapy (> or equal to 12%)

A.A 9 year old male with a FEV1/FVC of 0.85 and post- bronchodilator increase in FEV1 of 10%

B.A 4 year old female with a FEV1/FVC of 0.80 and a post- bronchodilator increase in FEV1 of 14%

C.A 32 year old male with a FEV1/FVC of 0.70 and a 15% increase in FEV1

D.A 24 year old female with FEV1/FVC of 0.75 and a post- bronchodilator increase in FEV1 of 20% (250 mL)

C and D

peak flow meters procedure

blow out hard and fast in a single blow, self -measured

short term use of peak flow meters

-Confirm diagnosis of asthma

-Assess response to treatment

-Establish a baseline for management of exacerbations

long term use of peak flow meters

-Managing patient's asthma

-Identify environmental causes of asthma symptoms

In which of the following situations would a peak flow meter be inappropriate?

A.Assessing therapeutic response of treatment for asthma in a 42 year old patient.

B.Confirming a diagnosis of asthma in a 12 year old patient.

C.Identifying environmental cause of symptoms in a 3 year old patient.

D.All of the above.

C

pa projection vs ap projection for x-rays

PA projection --> standard, beam passes from posterior to anterior of pt --> more accurate

AP projection --> magnifies anterior organs such as the heart, beam goes from anterior to posterior

-All white or completely radiopaque

bone

-White to grey

Water (soft tissue)

gray

fat

black or radiolucent

Gas (air)

what diseases do chest x-rays diagnose

-Pneumonia

-COPD

-Pleural Effusions

-Pulmonary Edema

-Atelectasis

-Lung nodules

-Tuberculosis

How long does it take for consolidation due to pneumonia to resolve on a CXR?

C

ultrasound

-high frequency waves that produces images of the body

CT scans

•3 - dimensional visualization of anatomical structures

CT with contrast

-element base?

-routes?

-IV route is used for?

-Barium or iodine-based

-Can be given oral, rectal, IV, intrathecal

-IV used for opacification of vascular structures and abdominal and pelvic organs

-5-12% of pts have adverse reactions

-contraindications include allergies, pregnancy, treatment of thyroid disease w/ radioactive iodine, chronic or acutely worsening kidney disease