Respiratory function in hoist rescue111

Aeromedical evacuation

Hoist Rescue

Sling single?

Double sling?

Stretcher?

Rescue basket?

Respiratory Function in Hoist Rescue: Comparing

Slings, Stretcher, and Rescue Basket

From CareFlight NSW, Northmead, NSW, Australia.

David Murphy , Alan Garner , and Rod Bishop

Aviation, Space, and Environmental Medicine x Vol. 82, No. 2 x February 2011

CareFlight NSW, Northmead, NSW, Australia

INTRODUCTION

A) single sling B) double sling

INTRODUCTION

C) stretcher

D) rescue basket

INTRODUCTION

INTRODUCTION

INTRODUCTION

So what happens?

General feelings of unease Dizzy, sweaty and other signs of shock Increased pulse and breathing rates

Then a sudden drop in pulse & BP Instant loss of consciousness If not rescued, death is certain

From suffocation due to a closed airway, or from lack of blood flow and oxygen to the brain.

Suspention trauma and harness-hang syndrome

INTRODUCTION

Suspention trauma and harness-hang syndrome

INTRODUCTION

INTRODUCTION

INTRODUCTION

INTRODUCTION

INTRODUCTION

When is a severe acute episodehappening?• Limited ability to speak• Pulsus paradoxus > 25mmHg• Pulse >110/min• RR >25-30/min• Flow rates <50% predicted• O2 saturation <91-92%• Some consider flow rates < 35% predictedto be life-threatening

INTRODUCTION

Sever Asthma

Stepwise approach ( children)

classificaticlassificationon

mild mild IntermitteIntermittentnt

Mild Mild persistentpersistent

Moderate Moderate persistentpersistent

Severe Severe persistentpersistent

Minor Minor symptomssymptoms

< 1/week< 1/week 1-3 /week1-3 /week 4-5/week4-5/week ContinuouContinuouss

exacerbatiexacerbation/ on/ nocturnalnocturnal

< 1/month< 1/month 1 /month1 /month 2-3/month2-3/month > 4 > 4 /month/month

PEF PEF between between attacksattacks

>80%>80% >80%>80% 60-80%60-80% < 60%< 60%

Step 1Step 1 Step 2Step 2 Step 3Step 3 Step 4Step 4

Stepwise approach ( adult)

classificaticlassificationon

mild mild IntermitteIntermittentnt

Mild Mild persistentpersistent

Moderate Moderate persistentpersistent

Severe Severe persistentpersistent

Minor Minor symptomssymptoms

< 2 /week < 2 /week 2-3 /week2-3 /week 4-5 /week4-5 /week ContinuouContinuouss

exacerbatiexacerbation/ on/ nocturnalnocturnal

< 2 < 2 /month/month

2-3 /month2-3 /month 4-5 /month4-5 /month > 5 > 5 /month/month

PEF PEF between between attacksattacks

>80%>80% >80%>80% 60-80%60-80% < 60%< 60%

Step 1Step 1 Step 2Step 2 Step 3Step 3 Step 4Step 4

Asthma classification

INTRODUCTION

Rescue Basket

(RB)>Stretcher

INTRODUCTION

H0 & H1 thesis

H1:Use of the RB would not be associated with impairment of spirometry in healthy volunteers

H0:Use of the Stretcher would not be associated with impairment of spirometry in healthy volunteers

INTRODUCTION

METHODS

Winch simulator

Randomized ,Controlled cross-over study

METHODS

Hypothesis Testing: Case-Crossover Studies

Study of “triggers” within an individual ”Case" and "control" component, but

information of both components will come from the same individual

”Case component" = hazard period which is the time period right before the disease or event onset

”Control component" = control period which is a specified time interval other than the hazard period



METHODS

METHODS

542-04-#38

Table of Random NumbersSequence - randomization

METHODS

METHODS

EasyOne Diagnostic Spirometer

METHODS

Pulmonary Function Testing

Perform test

Types of Spirometers

Bellows spirometers: Measure volume; mainly in lung function units

Electronic desk top spirometers: Measure flow and volume with real time display

Small hand-held spirometers: Inexpensive and quick to use but no print out

Volume Measuring Spirometer

Flow Measuring Spirometer

Desktop Electronic Spirometers

Small Hand-held Spirometers

Actual PFT Performance Technique

Prepare the equipment – find a nurse who knows (or is that nose?) what to do.

Patient should be seated with nose clip in place.

The patient needs to practice the exercise before actually performing the test. Have the patient breath in and out deeply several times.

Ask the patient to breath in as deeply as they can.


The patient should place their mouth completely over the mouthpiece, not inside it.

Ask the patient to blow out as fast and as quick as they can for at least six seconds. Enthusiatically coach the patient – jump, shout, get down, hoot and holler…

“Blow, blow, come on, blow more, you can do it!”


Once the patient has blown out as much as they can, ask them to then inhale as deeply as they can.

Repeat the whole test three times. The goal is to get a reproducible result that is consistent.

You may need to repeat the test more than three times in order to obtain an internally valid test.

Difinitions &Considerations

Lung Volumes and Capacities

There are four basic lung volumes: Inspiratory reserve volume (IRV) Tidal volume (TV) Expiratory reserve volume (ERV) Residual volume (RV)

In various combinations, these lung volumes then form lung capacities.

E.g., Vital capacity = IRV + TV + ERV

Lung Volumes

Normal Spirometry

Obstructive Pattern

■ Decreased FEV1

■ Decreased FVC

■ Decreased FEV1/FVC

- <70% predicted

■ FEV1 used to follow severity in COPD

Obstructive Lung Disease — Differential Diagnosis

Asthma

COPD - chronic bronchitis

- emphysema

Bronchiectasis

Bronchiolitis

Upper airway obstruction

Restrictive Pattern

Decreased FEV1

Decreased FVC

FEV1/FVC normal or increased

Restrictive Lung Disease —Differential Diagnosis

Pleural

Parenchymal

Chest wall

Neuromuscular

Spirometry Patterns

Indications for Pulmonary Function Testing

Patients 45 years old and older who have ever smoked.

Patients with prolonged or excessive cough or sputum production.

Patients with a history of exposure to lung irritants.


Detecting pulmonary disease Pulmonary symptoms – chest pain, orthopnea,

cough, phlegm production, dyspnea, wheezing

Physical findings – Chest wall problems, cyanosis, clubbing, decreased breath sounds

Abnormal labs/x-rays – ABG, Chest X-Ray


Assessing disease severity and progression Pulmonary disease – COPD, Cystic fibrosis, Interstitial

lung disease, Sarcoidosis

Cardiac disease – CHF, Congenital heart disease, Pulmonary hypertension

Neuromuscular disease – Amyotrophic lateral sclerosis, Guillain-Barre syndrome, Multiple sclerosis, Myasthenia gravis


Pre-operative risk stratification Thoracic surgery

Cardiac surgery

Organ transplantation

General surgical procedures

Evaluating disability and impairment

Contraindications for PFT

Relative contraindications for spirometry include hemoptysis of

unknown origin, pneumothorax, unstable angina pectoris,

recent myocardial infarction, thoracic aneurysms, abdominal

aneurysms, cerebral aneurysms, recent eye surgery (increased

intraocular pressure during forced expiration), recent abdominal

or thoracic surgical procedures, and patients with a history of

syncope associated with forced exhalation.

Normal Values

FVC is the total amount of air a person can exhale, usually measured in six seconds. 80 – 120% of predicted is a normal value 70 – 80% demonstrates mild

reduction/restriction 50 – 70% demonstrates moderate reduction <50% demonstrates severe reduction

FEV1 is the amount of air a person can exhale in one second. 80 – 120% of predicted is a normal value

Normal Values

FEV1/FVC ratio is the percentage of FVC that can be expired in one second. 75 – 80% is normal

60 – 80% demonstrates mild obstruction

50 – 60% demonstrates moderate obstruction

<50% demonstrates severe obstruction

Normal Values

FEF25-75 reflects small airway function >80% is normal

60 – 80% reflects mild obstruction in the small airways

40 – 60% reflects moderate obstruction

<40% reflects severe obstruction

Spirometry Interpretation: So what constitutes normal?

Normal values vary and depend on:

Height Age Gender Ethnicity

PFT Interpretation

PFT Interpretation

Three steps in interpretation

Is the test valid?

Interpret the test

Classify severity of disease if present

Validity

The test is valid is you have good patient effort and the three tests performed are internally consistent.

You may notice a learning curve in that the latter tests are better performed than the former.

Make sure that the tests are maximal effort. You need to be really aggressive in coaching your patient.

1 - good start of test : sharp take off 2- Meet end-of-test criteria

3- free from artifacts:

-Cough or glottis closure during the first second of exhalation

-Variable effort , submaximal effort

-Leak

-Obstructed mouthpiece

-Have a satisfactory exhalation 6 s of exhalation

Acceptability Criteria

After 3 acceptable spirograms been obtained

Are the two largest FVC within 150ml of each other?

Are the two largest FEV1 within 150ml of each other? If both of these criteria are met, the test session may

be concluded. If both of these criteria are not met, continue testing

until Both of the criteria are met with analysis of additional acceptable spirograms; OR a total of eight tests have been performed

Reproducibility Criteria

Interpretation of Spirometry

Step 1. Look at the Flow-Volume loop

Step 2. Look at the FEV1 (Nl ≥ 80% predicted).

Step 3. Look at FVC (Nl ≥ 80%).

Step 4. Look at FEV1/FVC ratio (Nl≥ 75%).

Step 5. Look at FEF25-75% (wide normal range)

Normal Values

FVC is the total amount of air a person can exhale, usually measured in six seconds. 80 – 120% of predicted is a normal value 70 – 80% demonstrates mild

reduction/restriction 50 – 70% demonstrates moderate reduction <50% demonstrates severe reduction

FEV1 is the amount of air a person can exhale in one second. 80 – 120% of predicted is a normal value

Normal Values

FEV1/FVC ratio is the percentage of FVC that can be expired in one second. 75 – 80% is normal

60 – 80% demonstrates mild obstruction

50 – 60% demonstrates moderate obstruction

<50% demonstrates severe obstruction

Normal Values

FEF25-75 reflects small airway function >80% is normal

60 – 80% reflects mild obstruction in the small airways

40 – 60% reflects moderate obstruction

<40% reflects severe obstruction

PFT Interpretation

Assess FVC, FEV1, and FEV1/FVC ratio.FVC and FEV1 normal, with a normal FEV1/FVC ratio:

Normal Test

FVC low, FEV1 low or normal, and a normal to high FEV1/FVC ratio:--Restrictive lung disease

FVC low or normal, FEV1 low, and a low FEV1/FVC ratio: Obstructive lung disease

Measurements Obtained from the FVC Curve

FEV1---the volume exhaled during the first second of the FVC maneuver

FEF 25-75%---the mean expiratory flow during the middle half of the FVC maneuver; reflects flow through the small (<2 mm in diameter) airways

FEV1/FVC---the ratio of FEV1 to FVC X 100 (expressed as a percent); an important value because a reduction of this ratio from expected values is specific for obstructive rather than restrictive diseases

Spirometry Interpretation: Obstructive vs. Restrictive Defect

Obstructive Disorders FVC nl or↓ FEV1 ↓ FEF25-75% ↓ FEV1/FVC ↓ TLC nl or ↑

Restrictive Disorders FVC ↓ FEV1 ↓ FEF 25-75% nl to ↓ FEV1/FVC nl to ↑ TLC ↓

Spirometry Interpretation: What do the numbers mean?

FVC Interpretation of %

predicted:

80-120% Normal 70-79% Mild reduction 50%-69% Moderate

reduction <50% Severe reduction

FEV1Interpretation of %

predicted:

>75% Normal 60%-75% Mild

obstruction 50-59% Moderate

obstruction <49% Severe obstruction

<25 y.o. add 5% and >60 y.o. subtract 5

Actual Predicted % PredictedFVC 4.0 4.5 88FEV1 3.4 4.2 89FEV1/FVC 85 82 112FEF25-75

Normal

Actual Predicted % PredictedFVC 2.0 4.0 50FEV1 1.8 3.7 47FEV1/FVC 90 82 112FEF25-75

Restrictive Pattern

Actual Predicted% PredictedFVC 4.0 4.5 88FEV1 2.4 4.2 58FEV1/FVC 60 82 76FEF25-75 2.2 4.450 Obstructive Pattern

Acceptable and Unacceptable Spirograms (from ATS, 1994)

PFTsPFTs

Normal vs. Obstructive vs. Restrictive

Variable Effort

Early Glottic Closure

Cough

Flow-Volume Loops

Flow-Volume Loops

Special Techniques

Beta Agonist Challenge Methacholine Challenge DLCO

Beta Agonist Challenge

Perform this when there is a suspicion that the obstructive defect may be reversible –> asthma.

Give the patient a beta agonist treatment (two puffs of an albuterol MDI or an albuterol nebulizer) and repeat the PFTs several minutes later. If you notice a 12% or more increase in FEV1, then you have diagnosed reversible airway disease/asthma.

Methacholine Challenge

If you have a suspicion that the patient might have Exercise-induced bronchospasm (EIB), then refer them to a pulmonary lab where they can do provocative testing with methacholine.

If the patient has a decrease in their FEV1/FVC ratio with the inhalation of methacholine, then you have diagnosed EIB.

Pretreat before exercise with albuterol or cromolyn.

Diffuse capacity of carbon monoxide in the lung DLCO

After performing the standard PFTs, the patient then inhales trace amounts of carbon monoxide.

CO traverses the alveolar capillary beds much more readily than CO2 or O2.

As such, most of the CO inhaled should be absorbed.

When it is not, this suggests pulmonary scarring consistent with pulmonary fibrosis. Search for a cause.

Diffusing Capacity

Decreased DLCO (<80% predicted)

Obstructive lung disease

Parenchymal disease

Pulmonary vascular disease

Anemia

Increased DLCO (>120-140% predicted)

Asthma (or normal)

Pulmonary hemorrhage

Polycythemia

Left to right shunt

paired T test

The paired t-test will show whether the

differences observed in the 2 measures will be

found reliably in repeated samples.

ANOVA:One way

If we have data measured at the interval level, we

can compare two or more population groups in

terms of their population means using a

technique called analysis of variance, or ANOVA.

Honestly significant difference test (HSD)

When you do multiple significance tests, the chance of finding a "significant" difference just by chance increases. Tukey´s HSD test is one of several methods of ensuring that the chance of finding a significant difference in any comparison (under a null model) is maintained at the alpha level of the test.

RESULTS

DISCUSSION

DISCUSSION

DISCUSSION

DISCUSSION

DISCUSSION

DISCUSSION

DISCUSSION

DISCUSSION

Air Turbulance

DISCUSSION

Major sources of noise generated by a helicopter

DISCUSSION

DISCUSSION

Static Spirometry

DISCUSSION

Dynamic Spirometry

DISCUSSION

DISCUSSION

Body Plethysmography

DISCUSSION

Body Plethysmography

DISCUSSION

helium dilution

DISCUSSION

DISCUSSION

DISCUSSION

DISCUSSION

134

THANKS FOR YOUR ATTENTION

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Respiratory function in hoist rescue111