basic life support (CPR) steps
DRS CAB
D → danger
- ensure scene safety
- “the surroundings are safe”
R → Response
- 3x shoulder taps
- “are you okay?”
S → shout for help
- call for ambulance/ask for AED
C → circulation
- check carotid pulse on the neck
A → airway
- look for any obstruction in the nose or mouth
- tilt head up to make sure airway is clear
B → breathing
- look at chest for rise and fall
begin CPR
100-120 chest compressions/min
adults = 30 compressions then 2 breaths
AED protocol: once AED has arrived, apply AED and follow protocol
how does CPR differ for an infant vs an adult?
infant:
- tap on sole of foot instead of shoulders to see if okay
- palpate branchial artery instead of carotid
- give compressions using your thumb
- AED pads go on back and chest instead of just chest
if 2 rescuers are present then infants get 15 compressions and 2 breaths otherwise just 30:2
manual BP top and bottom numbers
when you first hear the heart sound is the systolic value (top number)
when you stop hearing it is the diastolic value (bottom number)
untwist slowly otherwise you will miss it
ECG heart rate calculation
300/# of large squares
1500/# of small squares
b/w consecutive R-R intervals
ECG strip, speed of 25 mm/sec means 1 small sq is how many secs?
0.04 sec
normal direction of mean QRS vector?
between +20 to +100º
average being around +60º
how many limb leads are recorded in a standard ECG?
12 leads
- 3 bipolar limb leads (I, II, III)
- 3 unipolar limb leads (avR, avF, avL)
- 6 unipolar chest leads
time interval of PR interval & QT interval
PR interval: 0.12-0.20 secs (avg. 0.16 secs)
QT interval: 0.35-0.45 secs
U wave in ECG
not present normally
due to slow repolarization of papillary muscles
what features are observed when palpitating pulse?
- rate
- rhythm
- character
- volume/strength
- delay
- condition of vessel (not that easy to comment on though)
what is an arterial pulse and how is it produced?
rhythmic expansion & recoil of an artery due to ejection of blood from left ventricle into aorta during systole.
produced when this pressure wave travels along arterial walls
where is apex beat palpitated?
5th intercostal space at level of mid clavicular line
- move right from angle of louis (sternal angle) - this is the second rib
- keep going down til you get to the 5th intercostal space
significance of apex beat + clinical conditions are associated with displacement of apex beat?
significance:
- determine position & size of heart
- assess force & character of ventricular contraction
- detect abnormalities such as displacement
clinical conditions where displaced:
- left ventricular hypertrophy
- pneumothorax/ lung collapse
auscultation of heart sounds (locations of where to listen to these heart sounds for each valve)
aortic valve: 2nd intercostal space to the right of sternum (right next to it)
pulmonary valve: 2nd intercostal space to the left of sternum (right next to it)
mitral valve: 5th intercostal space, mid clavicular line
tricuspid valve: fourth left intercostal space at the lower left sternal border (near the xiphoid process)
why are heart murmurs normally heard in anemia?
because in anemia, blood viscosity decreases and so does cardiac ouput = turbulent flow
what is the physiological basis of the splitting of the 2nd heart sound during deep inspiration?
because during deep inspiration, venous return to heart increases = delayed closure of pulmonary valve
left heart filling decreases leading to earlier closure of aortic valve causing S2 to split into 2 components
name the apparatus for blood pressure measurement
sphygmomanometer
cant say BP machine otherwise will get points off
mean arterial pressure + formula
avg. pressure that remains most of the time within arteries
mean arterial pressure = diastolic pressure + 1/3 pulse pressure
normal value of pulse pressure is 40 mmHg and that of mean arterial pressure is about 93 mmHg
JVP is elevated in what conditions?
- fluid overload (most characteristically in heart failure)
- acute pulmonary embolism
- chronic obstructive pulmonary disease (COPD)
- right heart dilatation
JVP measurement steps
- patient sits/lays at 45º angle
- head is tilted slightly to the right
- observe under light to find the venous pulsations - try to locate the upper level of the vein
- place 1 ruler downward on the sternal angle and another at the upper level of the vein
- whatever reading you get, add it to 5
total should be less than 8cm otherwise there is some issue
JVP isn’t always that easy to see
JVP graph points/what event they represent
a wave → atrial contraction
c wave → ventricular contraction (bulging of tricuspid valve into right atrium during this time)
x descent → atrial relaxation & downward pull by contracting ventricles
y descent → rapid ventricular filling due to opening of tricuspid valve
v wave →
venous filling of right atrium during late systole
wright’s peak flow meter
used for measuring peak expiratory flow rate (PEFR)
basically just blow into it and how far it goes is the rate of airflow
what is normal PEFR?
400-600 L/min
whats the difference between PEFR and FVC?
PEFR measures the maximum speed of airflow during exhalation, while FVC measures the total amount of air that can be forcibly exhaled after a maximal inhalation
