Physiological Indicators

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Physiological Indicators

• Brian McFetridge
• Lecturer in Nursing
• University of Ulster

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Florence Nightingale
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Plan for the afternoon!

• We will examine the anatomy and physiology of the
  heart and lungs
• We will examine a patients case study during an
  illness to establish how their heart and lungs
  may react
• Practice some of the physiological tests to
  assess the respiratory / cardiac systems

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Case Study

• Barry is a 58 year old gentleman who attended AE
  with severe crushing pain in his chest.
• What might the cause of this
• pain be?
• What will the healthcare staff do?

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• The Heart
• Describe the size, shape location of the heart
• Size - size of closed fist
• Shape cone shaped
• Position behind sternum, within medinastinum of
  thoracic cavity between lungs, slightly more to
  the left
• Heart is enclosed by pericardium (serous
  membrane) (fig 20.2c)

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The Heart Wall Composed of 3 layers 1. Outer
Epicardium visceral pericardium Thin
transparent serous membrane covering outer
surface of heart Anchors, protects prevents
overstretching of heart 2. Middle Myocardium
Thickest layer of heart wall Composed of cardiac
muscle, blood vessels (coronary circulation)
nerves 3. Inner Endocardium Inner lining of
heart Continuous with epithelium of blood vessels
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Four Chambers of the Heart

• Heart is divided into right and left sides by
  septum
• Each side is further divided by atrioventricular
  valves into upper lower chambers

• 2 x Atria upper chambers (receiving chambers),
  small thin walled
• 2 x Ventricles lower chambers (discharging
  chambers), thick walled muscular pumps - create
  pressure needed to push blood through blood
  vessels

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Four valves of the Heart

• Blood flows through heart in one direction, from
  atria to ventricles out through the arteries
• One-way system enforced by heart valves
• Valves open close in response to differences in
  blood pressure on either side of valves

2 x Atrioventricular valves Tricuspid
Bicuspid valves 2 x Semi-lunar valves Aortic
Pulmonary valves
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Blood Flow Through the Heart
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Pathway of Blood through the Heart fig21.20

• Right atrium receives O2 poor blood from three
  systemic veins
• Superior Venae cavae returns blood from body
  regions above diaphragm
• Inferior Venae cavae returns blood from body
  region below diaphragm
• Coronary Sinus collects blood draining from
  myocardium (coronary circulation)
• Blood moves to right ventricle (tricuspid valve)
  is pumped out through pulmonary artery/trunk
  (pulmonary valve) to lungs
• Pulmonary trunk divides into left right
  pulmonary arteries
• Pulmonary arteries divide subdivide into
  smaller arteries, arterioles, capillaries
• Gas Exchange occurs between capillaries alveoli
  
• CO2 is unloaded O2 is picked up
• Capillaries merge to form venules veins

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• Left atrium receives O2 rich blood from four
  pulmonary veins (two from each lung)
• Blood moves to left ventricle (bicuspid valve)
  is pumped out through systemic arteries (aortic
  valve) to body tissues
• Blood is pumped out through the aorta largest
  artery in the body
• From there blood is transported via smaller
  systemic arteries to body tissues
• Gases nutrients are exchanged across capillary
  walls
• Systemic veins return O2 poor CO2 rich blood to
  right atrium
• the cycle begins again

Great Arteries Pulmonary Trunk Aorta Great
Veins Superior Inferior Venae
Cavae Pulmonary Veins
Coronary circulation supplies blood to muscle
tissue of heart
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Differences between Arteries Veins

• Walls of arteries are thicker than walls of veins
• (Tunica media contains more smooth muscle
  elastic fibres)
• Blood pressure is higher in arteries
• Veins have larger diameter/lumen than arteries
• Veins contain valves (prevent backflow of blood)

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Heart is a Double Pump Serving Two Separate
Blood Circuits/Systems

• 1. Pulmonary system (pulmonos lung)
• Consists of blood vessels that carry blood to and
  from lungs
• Right side of heart pumps blood through pulmonary
  circuit
• Blood flowing through pulmonary circuit gains O2
  loses CO2
• Short low pressure circuit
• Walls of right ventricle thin right side of
  heart is pulmonary circuit

• 2. Systemic System
• Consists of blood vessels that carry blood to and
  from body tissues
• Left side of heart pumps blood through systemic
  system
• Blood flowing through systemic circuit loses O2
  gains CO2
• Long high pressure circuit
• Wall of left ventricle much thicker than right
  ventricle left side of heart is systemic circuit

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Oxygen Carbon Dioxide Content of Blood

• As a rule
• Veins carry O2 poor blood to the heart from rest
  of body
• Arteries carry O2 rich blood from heart to rest
  of body

VEAL

• Systemic veins carry O2 poor CO2 rich blood from
  tissues to right atrium
• Systemic arteries carry O2 rich, CO2 poor blood
  from lungs to left atrium

Opposite situation exists in pulmonary circuit

• Pulmonary veins carry O2 rich CO2 poor blood from
  lungs to left atrium
• Pulmonary arteries carry O2 poor CO2 rich blood
  from right ventricle to lungs

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• What is important to all organs in the body?

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• A constant supply of oxygen rich blood.

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Coronary Arteries

• The coronary arteries arise in the sinus
• valsalva situated at the base of the aorta.
• Left Coronary Artery- Supplies the bulk of the
  left ventricle. It also supplies the myocardium,
  portions of the right ventricle and the septum.
• Right Coronary Artery- Supplies the right atrium
  and the right ventricle and a portion of the left
  ventricle.

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Coronary Arteries
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• Do doctors and nurses hold patients hands for a
  reason?
• What reason?

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Pulse

• Pulse is an impulse transmitted to arteries by
  contraction of the left ventricle. It can be
  palpated where an artery near the body surface
  can be pressed against a firm structure
• Average rate for an adult is 60-100.
• Tachycardia Abnormally fast heart rate ie. gt100
  beats/min
• Bradycardia Heart rate slower than 60
  beats/min
• Most commonly assessed using the radial artery
  although there are other sites.

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Pulse Sites
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The procedure

• Ideally patient should rest for a few mins before
• Locate the radial artery and place 2nd and 3rd
  fingers along it - press gently
• Count the pulse for 60 secs
• Rate Resting adult has a pulse of 60-100
  beats/min
• Rhythm Should be regular
• Amplitude Reflects pulse strength and
  elasticity of th artery wall
• Document

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What next?

• Barrys pulse was discovered to be irregular.
• What test can be perform next to give us more
  detail about heart?

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What is an electrocardiogram?

• A graphic recording of the electrical activity
  generated in the heart and mapped against time..

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Cardiac Conduction
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The Conduction System

• Contraction of heart muscle is preceded by
  electrical changes called depolarisation.
• Repolarisation occurs when the heart muscle is
  relaxed.
• Even though the heart has four chambers it can be
  considered,from an electrical point of view,to
  have 2 since the atria and ventricles contract
  simultaneously.
• During the cardiac cycle, a series of action
  potentials are produced which are recorded as
  waves on an ECG.

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The Conduction System

• Sino Atrial Node is the predominant pacemaker.
• Discharge rate is 70-80 BPM in a healthy adult.

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PQRST

• One complete cycle of the conduction
• system produces what is known as the
• PQRST complex on an ECG.

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PQRST

• P Wave - represents impulse spread across both of
  the atria.
• P-R Interval - represents a short period of delay
  within the AV node essential for allowing the
  Atria to complete contraction.

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PQRST

• QRS- Represents depolarisation down the Bundle of
  His, L and R Bundle Branches, Purkinje Fibres
  penetrating the myocardium and stimulating
  contraction.

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PQRST

• ST Segment - represents the period from the end
  of ventricular contraction to the start of
  repolarisation.
• T Wave - Ventricular Repolarisation.

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Common Cardiac Rhythms

• Sinus Rhythm

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Sinus Bradycardia

• 3-5
  2-2.5

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Sinus Tachycardia

• 3-5
  2-2.5

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Atrial Fibrillation
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Atrial Fibrillation
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Ventricular Fibrillation
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Asystole
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What is Blood Pressure?

• Blood pressure refers to the hydrostatic pressure
  exerted by the blood on the blood vessel walls.
  It is generated by the contraction of the
  ventricles.
• It is a function of blood flow and vascular
  resistance.
• Systolic maximum pressure of the blood against
  the wall of the vessel following ventricular
  contraction
• Diastolic Minimum pressure of the blood against
  the vessel wall following closure of the aortic
  valve.

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BARRY
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Blood pressure (BP) values Normal BP can range
from 100/60 to 150/90

• There is no agreed values for normal upper
  limits of blood pressure (BP).
• BP varies from person to person and also from
  moment to moment.

• Factors such as age, sex, and race can influence
  BP values. Pressure also varies with exercise,
  emotional reactions, sleep, digestion and time of
  the day.

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• Hypotension Low blood pressure. Generally
  defined in adults as a systolic BP lt100mm/Hg
• Hypertension Defined as an elevation of
  systolic blood pressure. Never diagnosed on a
  single BP measurement.

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Korotkoff Sounds

• A series of five phases that can be heard as BP
  falls from the systolic to diastolic
• Phase 1 clear tapping recorded as the systolic
  pressure
• Phase 2 a softening of the sound may become
  swishing
• Phase 3 return of sharper sounds not as intense
  as 1
• Phase 4 muffling sound becomes soft and blowing
  (diastolic 4)
• Phase 5 disappearance of sound (diastolic 5)

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When to monitor BP

• Admission to establish baseline
• Monitor fluctuations or effectiveness of
  treatment.
• Pre and post-operatively
• Critically ill patients
• Those receiving blood transfusions
• Intravenous fluid to monitor for circulatory
  overload

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Taking blood pressure

• Explanation to patient
• Preparation of patient equipment - Stethoscope
  sphygmomanometer

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• Allow patient to rest approx 3 mins prior to
  recording BP
• Ensure arm is supported and positioned at heart
  level. Tight/restrictive clothing removed
• Apply cuff snugly to arm ensuring centre of
  bladder covers brachial artery
• Palpate radial pulse and inflate cuff until pulse
  not felt. This provides an estimation of
  systolic pressure. Deflate cuff completely.
• Wait 15-30 seconds
• Place diaphragm of stethoscope over brachial
  artery

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• Inflate cuff further 30mmHg from estimated
  systolic pressure
• Deflate cuff 2-3mmHg per second
• Record systolic to nearest 2mmHg (Phase 1)
• Continue slow deflation recognise phases
• Document diastolic (Phase 4/5 depending on
  policy, condition etc)
• Clean ear piece and cuff
• Document
• Report any abnormalities to medical team
  immediately !!!

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Capillary Refill
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• We then discover that Barry has a history of
  breathing difficulties. The Nurse decides to
  assess his respiratory condition.

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Assessing respiratory function.
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Respirations

• It is the function of the respiratory system to
  supply the body with oxygen and remove carbon
  dioxide.
• The body requires a continuous supply of 02 to
  carry out vital functions and this is provided by
  respiration.

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Monitoring respiration

• Patient should be relaxed and resting.
• Observe movement of chest wall and count
  respirations for 60 secs
• If difficult to observe, place hand gently on
  chest wall
• Observe rhythm and depth
• Observe patients colour for signs of cyanosis
  blueness especially around lips
• Observe for symmetry of chest movement
• Also observe for
• Pain, difficulty, noisy respiration, cough,
  sputum
• Document

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• Barry received the necessary treatment to
  alleviate his symptoms. However, while the nurse
  was assessing his respiratory rate and rhythm,
  Barrys breathing became wheezy. Barry is an
  asthmatic. During his stay in hospital, it was
  suggested to record his peak flow.

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Peak Flow

• A peak flow meter is a simple device that can
  measure air flow from your lungs. This can
  indicate improvements or deteriorations in
  condition.

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Recording Peak Flow

• Zero meter
• Stand upright
• Take deep breath
• Make seal with mouth around mouthpiece
• Blow out as hard as you can
• Note the reading
• Repeat a further two times
• Peak flow is your highest reading
• Record

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• Thankfully, Barry recovered due to the insight
  those caring for him had. They had a full
  understanding of the physiology of the body and
  what happens when there is a disturbance in the
  normal physiology.