ISP Lab Exams

The four respiratory tests of ISP lab 2

Measuring rest breath

Breath hold (time)

Lung volumes and capacity (**slow spirometry**)

Measuring FVC and expiratory flow volume curve (forced spirometry)

VM, RF and VT meanings

Minute ventilation

Respiratory frequency

Tidal volume

Label the following

What activities should be avoided prior to lung function testing? (lab 2)

Smoking within an 1hr

Alcohol within 4 hrs

Vigorous exercise within 30 mins

Clothing that is restrictive

Large meal within 2hrs of testing

Concentratiosn of N, O and CO2 at atmosphere?

78% N

21% Oxygen

Henry’s law

Gas diffuses proportional to partial pressure of the gas

Central vs peripheral chemoreceptors

Central (of the brain) - sensitive to carbon dioxide (as measured via pH)

Peripheral - oxygen, carbon dioxide and pH of blood

What is pulmonary ventilation?

The amount of air exhaled per minute

What does forced spirometry show?

Maximum air exhaled in a single breath and resistance to air flow

What information is required for spirometry (personal info)

*Ethnic group*

*Gender*

*Date of Birth*

*Height*

*Weight (not important tho?)*

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How to measure breath hold?

After a minute of quiet breath (or two minutes), hold breath at end of next quiet inspiration

When did the breath hold time become the highest?

After hyperventilating

Shortest after rebreathing from paper bag (where Co2 is higher to start with)

Hypercapnic drive was low to start with

When did you stop breathing when performing an FVC?

Noseclip was on, end of quiet expiration- exhale maximally until 6S timer turns green.

Should have repeated three times w one minute rest.

MV, TV and FR?

MV = TV and FR

Estimate dead space volume for a 50kg woman.

50\*2.2 + 30ML

140mL (Or 110mL)

Alveolar vs minute ventilation

Alveolar excludes dead space (FRC)

PaCO2

partial pressure of carbon dioxide in arterial blood

VCO2 \* 0.863/VA (L/min)

= rate of CO2 production \* 0.863 / alveolar ventilation

How to assume VCO2?

2\.8\*weight = mL/min

Normal range for PaCo2

40-45 mmHg

* high = hypoventilation
* low = hyperventilation

im confused… ask joanne!

Calculate VC, TLC (53kg person), FRC and IC

3\.6, 4.8 (estimate RV to be 1.2L), 1.7 and 3.1

What are medikro values based on

Height, age, sex, ethnicity

(**not weight, weight is not part of the parameters?**)

fill this out

What are acceptable measurements/trials for a expiratory flow volume curve?

Produce two attempts that are within 0.15L of each other

Why is FEF50 useful

Can identify flow in effort dependent stage (when half volume is expired and its hard to get air out)

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Shows obstructive disease

Estimate PaCo2 for a 65 kg man, assuming

VCo2 = 2.8\* weight and

PaCo2 = VCO2 x 0.863/VA

RF = 12

TV = 0.6 V

VD = 0.1

26\.18 mm Hg = hypocapnic

The first Korotkoff sound correlates with __ BP

systolic

A 12 lead ECG is obtained from the placement of ___ electrodes.

__ leads recording between 2 single electrodes

___ lead recordings between a single electrode + avg of 2 others

___ lead recordings from a single electrode on the chest

10, 3 (bipolar limb leads) ,3 (augmented limb leads), 6 (unipolar precordial/chest leads)

How many ECG rhythms have the word sinus in them?

5

Normal RR, HR, PR interval

RR- 0.6s-1.0s

HR- 60-100bpm

PR- 0.12-0.2s

Normal QRS duration and QT interval

QRS < 0.12

QT = 0.36-0.44s (for resting HR 60-70bpm)

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What are the three phases of cardiac action potential?

Rapid depolarisation, plateau depolarisation and repolarisation

Where should RA and LA electrodes be placed?

Below mid clavicle

Where should V1-V6 be placed?

V1- palpate down to sternal angle and go to right sternal border (IC2) and down two spaces (IC space 4)

V2 - left sternal border (IC space 4)

V3- half way between V2 and V3

V4- IC space 5 in left mid clavicle line

V5- anterior axillary line

V6- mid axillary line

What forms the sternal angle?

Angle of louis- manubrium of sternum and body of sternum (lines up w IC 2)

Where should RL and LL be placed? (ECG)

mid clavicular lines at costal margin

What to do if ECF trace is noisy?

Subject relaxes, check adhesion to skin and secure connection to cable

What are the 4 ECG recordings taken?

1. Subject completely relaxed
2. Subject breathing slowing (Sinus arrhythmias)

3\.+4 Subject lying of left and right lateral sides (for MEA analysis)

What are hallmarks of a normal sinus rhythm?

1. Regular RR intervals
2. Identical P waves (lead II)
3. Narrow and identical QRS (lead II)


1. Every p wave is followed by QRS (lead II)

What is the QT interval corrected for?

HR and sex?

If PR interval was lengthened consustently

, this would indicate

heart block type I

If QRS was lengthened, what could this be?

PVC, VTAC, 3rd degree heart block

What is Long QT syndrome?

heart signaling disorder that can cause fast, chaotic heartbeats (arrhythmias). A heart signaling disorder is also called a heart conduction disorder

Which leads show inferior, LL and anterior?

Inferior - II, III, a VF

LL: I, v5, v6, aVL

Anterior - V1 → V4

What are the national guidelines for BP?

What does RPP measure?

Rate pressure product- looks at amount of stress placed on heart

* AT rest: RPP shows if heart is under excessive strain
* During exercise: RPP examines response to physical exertion (MI or abnormal rhythm may be detected)

Label the diagram ^^

What is the normal axis range? (MEA)

\-30 to 120 degrees

draw the four different MEAs

What does looking at the leads with the largest positive R waves show?

MEA is somewhere in between

What is a biphasic limb lead? (lab 1)

If QRS is biphasic = MEA is approx at right angles

Purpose of taking right and left sides (lying laterally) for ECGs?

Technique called a "right lateral decubitus ECG" and a "left lateral decubitus ECG”

* Right side: look at right ventricular hypertrophy, right heart block problems
* Left side: same deal

Helps identify rhythms that are not identifiable when lying supine

What causes LVH?

Pressure overload - aortic stenosis or hypertension or in extreme athletes

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How to characterise LVH?

Left side leads will show increased R wave amplitude (I, avL, V4-V6)

Right side leads will show increased S wave depth (III, aVR, V1-3)

**Further: classifications/ECG voltage criteria**

**(where 10mm = 1 mV)**

How to prepare for BP measurement?

Seated for 5 minutes w ith elbow flexed

Chair has back support, feet on ground

Subject should not have ingested food or drugs within last 30 minutes

No exercise the hour prior

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What are the 5 different korotkoff sounds? which are clinically significant?

1- beginning of repetitive tapping (SBP)

2- soft/swishing (no important)

3- sharper and maybe louder tapping than 1st (not important)

4 - sound becomes muffled

5- sound disappears (DBP)

How to take BP

Wrap cuff around arm with arm supported at level of heart (cuff aligned w brachial artery)

Inflate to 160 mm Hg (\~20 mmHG above systolic)

Release at 2-3 mm Hg/sec

How many BP readings?

2 measurements (Min 1 min apart)

Average

Take 3rd if systolic differents by more than 10 mm Hg

Potential errors in BP reading

Inaccurate sphygmomanometer

Improper cuff size

Auditory acuity of tech

Rate of inflation/deflation

Experience/reaction time

Improper placement or max inflation

background noise

subject holding onto something

physiological abnormalities (damaged brachial artery)

What does NIBP stand for?

Non invasive blood pressure devicie

MAP should be estimated using which arm?

Non dominant-

diastolic + (systolic-diastolic) / 3

FOrmula for RPP

RPP = HR \* SBP

What are the NHF classifications for BP

yayyyy don’t need these

correct pressure for initial cuff inflation

160mmHg (clinically, 200 mmHg)

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Correct rate of cuff deflation

2-3 mmHg per minute

Why measure BP in both arms?

To identify peripheral artery disease

damage of aorta

atherosclerosis

Stenosis of subclavian artery

Why measure BP in different positions?

Orthostatic hypertension: significant drop in blood pressure upon standing (accompanied with dizziness/faintness)

Drop in blood pressure could also suggest hypovolemia (dehydration)

What is the auscultatory gap? What happens if it is not recognised?

Period of diminished or absent Korotkoff sounds during the manual measurement of blood pressure. It is associated with reduced peripheral blood flow caused by changes in the pulse wave.

Silent interval that may occur between the initial appearance of Korotkoff sounds (phase I) and their re-appearance after a temporary absence (phase II).

**If the auscultatory gap is not recognized, it can result in underestimating the true systolic blood pressure and overestimating the diastolic blood pressure.**

One small square = _ s (ECG)

0\.04 secs

What would a beta blocker do to heart rate?

Decrease BP and HR to reduce CO (response to hypertension)

Physiological basis of sinus arrhythmia?

Inspiration = increase HR

Expiration = decrease HR

Vagus nerve can influence

ECG criteria for clinically significant ST depression/elevation

greater than or equal to 1mm

ischemia vs infarction on an ECG

ischemia = ST depression (subendocardial injury)

infarction = ST elevation (transmural/epicardial injury)

Sinus arrest vs sinus exit block

Sinus exit block - skip a beat but comes back at same HR

Sinus arrest- stop and new HR start

Main electrophysiological different between atrial tachycardia and atrial fibrililation

Tach = regular

fibrill = irregular

Difference between second degree type I and type II AV block

type I - PR interval gets progressively longer

type II - more P waves than QRS

Is VFib or VTAC worse?

VGib = rhythm and rate are both affected

Unifocal vs multifocal in PAC/PVC

When describing premature atrial contractions (PACs) or premature ventricular contractions (PVCs), "unifocal" and "multifocal" refer to the pattern or origin of these abnormal heartbeats.

Unifocal=premature beats that arise from a single ectopic focus or site within the atria (in the case of PACs) or ventricles (in the case of PVCs). This means that all the abnormal beats have the **same morphology or appearance**

multifocal= multiple ectopic foci or sites within the atria or ventricles. This means that the abnormal beats have varying morphologies or appearances

Premature ventricular contraction vs complex

“premature ventricular contraction" emphasizes the timing aspect,

"premature ventricular complex" highlights the complex nature of the abnormal beat.

Calculate BMI for 183cm male who wear 82kg

24\.49 (average health risk)

What is used to estimate BSA?

Weight and height

What does STPD stand for?

Standard temperature and pressure (dry)

What is definitive method for estimating body density?

Skin fold measurements

What does BIA stand for?

Bioelectrical impedance analysis (used for body fat estimate)

Four sites to measure skinfold thickness

Triceps, biceps, subscapular, iliac crest

What is BMR?

Basal metabolic rate = amount of energy to function on complete rest (just wake up, not eat for 12 hours, lie in dark room w no external stimuli)

What is RMR?

Surrogate for BMR (lying down for two hours, eyes closed and not eaten for previous 2 hours)

What does measuring oxygen consumption help with for indirect calorimetry?

Help estimate energy expenditure (aerobic metabolism)

Write this expression in words/fully expanded

Rate of oxygen consumed= rate at which oxygen is inspired - rate at which oxygen is expired

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Oxygen inspired= estimate rate w VE \* fraction oxygen in inspired air (0.2093)

Oxygen expired = VE (gas meter) \* oxygen in expired air (o2 analyser)

What is the value for FIO2?

0\.2093 (fraction of oxygen in inspired air)

What does RQ help with ?

Respiratory quotient: helps give balance between CHO and fat burning (generate different amount of energy for each litre of oxygen consumed)

CHO RQ = 1

Fat RQ = 0.7

(ignore proteins, % is small and RQ is between CHO and fat)

Why can we ignore FICO2 in VCO2?

Its so small (0.0004), can be considered 0

How to measure FeCO2

CO2 analysis of expired air

What state must VCO2 and VO2 be measured?

steady state= metabolic and respiratory gas exchange being in equilibrium

Why is RER considered the RQ?

Respiratory exchange ratio (RER) is RQ estimated by metabolic gas exchange

LAB 3: How long should volunteer being lying down before beginning measurements

(5) 10 minutes, breathing through facemask

Process of lab 3 + using the taps

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Tap should be turned to **the bag so expired air is diverted into it for 5 minutes (closing tap at end of expiration). Record pulse rate (eyes should have been closed)**

How to analyse expired air? (Lab 3)

Room temp and barometric pressure

Gas analyser- turn tap to connect sampling line and inlet tube and start stopwatch. 60 seconds of sampling (record exact time for both O2 and Co2)

**Note sampling rate = 280ml/min**

**close tap to the bag**

Go to volume measuring station, connect, read initial reading and turn tap to connect bag to gas meter

What does the expiratory volume calculation (converting STPD to ATPS) assume?

RT = 22 degrees and Pbar = 760 mmHg

Calculate RMR if RER = 0.84 and VO2 is 0.2542

%CHO = (RQ - 0.7) / 0.003

46\.67%

(Fat % 53.33%)

RMR = 5.19 kJ/min

To convert to kJ/hour/m2 divide by BSA and \* 60

Average male and female RMRs

Female =150

Male = 160 kJ/hour/m2