Bed side pulmonary function tests 7
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pulmonary function tests
Transcript of Bed side pulmonary function tests 7
• Pulmonary function tests have been used traditionally in
the preoperative assessment before any major surgery.
INDICATIONS
To predict the presence of pulmonary dysfunction
To know the functional nature of disease (obstructive or
restrictive. )
To assess the severity of disease
To assess the progression of disease
To assess the response to treatment
To identify patients at increased risk of morbidity and
mortality, undergoing pulmonary resection.
To identify patients at perioperative risk of pulmonary
complications
Degree and severity of impairment
Identify the site of airway obstruction
1) Sabrasez breath holding test:
Ask the patient to take a full but not too deep breath
& hold it as long as possible.
>25 SEC.-NORMAL Cardiopulmonary Reserve
15-25 SEC- LIMITED CardioPulmonary Reserve
<15 SEC- VERY POOR CardioPulmonary Reserve
(Contraindication for elective surgery)
25- 30 SEC - 3500 ml VC
20 – 25 SEC - 3000 ml VC
15 - 20 SEC - 2500 ml VC
10 - 15 SEC - 2000 ml VC
5 - 10 SEC - 1500 ml VC
2) Single breath count:
After deep breath, hold it and start counting till the next
breath.
Normal- 30-40 COUNT
Indicates vital capacity
3) SNIDER’SMATCH BLOWING TEST:
Measures Maximum Breathing Capacity.
Should take 6 attempts
Ask to blow a match stick from a distance of 6” (15
cms) with
Mouth wide open
Chin rested/supported
No pursed lips
No head movement
No air movement in the room
Mouth and match stick at the same level
• Can not blow out a match
• MBC < 60 L/min
• FEV1 < 1.6L
• Able to blow out a match
• MBC > 60 L/min
• FEV1 > 1.6L
• MODIFIED MATCH TEST of Olsen:
DISTANCE MBC
9” >150 L/MIN.
6” >60 L/MIN.
3” > 40 L/MIN.
4) GREENE & BEROWITZ COUGH TEST:
DEEP BREATH F/BY COUGH
ABILITY TO COUGH
STRENGTH
EFFECTIVENESS
INADEQUATE COUGH : FVC<20 mL/Kg
FEV1 < 15 ml/Kg
PEFR < 200 L/min.
VC ~ 3 TIMES TV FOR EFFECTIVE COUGH.
A wet productive cough / self propagated paroxysms of
coughing – patient susceptible for pulmonary
Complication.
5) FORCED EXPIRATORY TIME:
After deep breath, exhale maximally and forcefully &
keep stethoscope over trachea & listen.
Normal FET – 3-5 SECS.
Obstructive Lung Disease - > 6 SEC
Restrictive Lung Disease - < 3 SEC
6. RESPIRATORY RATE
• Essential yet frequently undervalued component of PFT
• Imp. evaluator in weaning & extubation protocols
• Increase RR ‐ muscle fatigue ‐work load ‐ weaning fails
7) DE BONO’S WHISTLE BLOWING TEST:
MEASURES PEFR.
Patient blows down a wide bore tube at the end of which
is a whistle, on the side is a hole with adjustable knob.
As subject blows → whistle blows, leak hole is gradually
increased till the intensity of whistle disappears.
At the last position at which the whistle can be blown ,
the PEFR can be read off the scale.
8)Wright ‘s Respirometer :
measures VT and minute volume
Simple and rapid
Instrument- compact, light and portable.
Disadvantage: It under- reads at low flow rates and over-
reads at high flow rates.
Can be connected to endo tracheal tube or face mask
Prior explanation to patient is needed.
Contd…
Ideally done in sitting position.
MV- instrument record for 1 min. And read directly
VT-calculated and dividing MV by counting Respiratory
Rate.
Accurate measurement in the range of 3.7-20
L/min.(±10%)
USES: 1)Bedside PFT
2) ICU – Weaning Pts. from Ventilator.
References
1) SNIDER,T. H.Simple Bedside Test of Respiratory Function. J. Am. Med. Assoc.
170:1631, 1959.
2) CARILLI, A. D. and J. R. HENDERSON. Estimation of Ventilatory Function by
Blowing Out a Match. Am. Rev. Resp. Dis. 89:680, 1964.
3) OLSEN, C. R. The Match Test: A Measure of Ventilatory Function. Am. Rev. Resp.
Dis. 86:37,1962.
4) WRIGHT, B. M. and C. B. McKERROW. Maximum Forced Expiratory Flow Rate as a
Measure of Ventilatory Capacity. Br. Med. J. 2:1041, 1959.
5) DE BONO, E. F. A Whistle for Testing Lung Function. Lancet 2:1146, 1963.
