Patient Monitoring Test 2

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% of O2 carried in plasma

2%

% of oxygen bound for hemoglobin

98%

Fully Saturated RBC 4x O2 bound

Oxyhemoglobin (HbO2)

No O2 bound to RBC

Deoxyhemoglobin

Atmospheric pressure

760mmHg

Oxygen Composition/partial pressure

21% 160mmHg

Nitrogen composition/partial pressure

78% 0.3mmHg

CO2 composition/partial pressure 

0.04% 590mmHg

H2O composition/Partial Pressure

0% 0mmHg

Alveolar Composition/partial pressure of oxygen

13.6% 160mmHg

Alveolar Composition/Partial Pressure of CO2

5.3% 40mmHg

Alveolar Composition/Partial Pressure of nitrogen

74.9% 569mmHg

Alveolar Composition/Partial Pressure of H2O

6.2% 47mmHg

Atrial Blood Gasses

ABGs assess the patient’s oxygenation at the tissue level

Normal Values PaO2

90-100 mmHg

Normal Values PaCO2

35-45 mmHg

Normal Values PaHCO3

22-29 mmHg

Normal pH Values

7.35-7.45 mmHg

Blood Values Arteries

PaO2 = 90-100 mmHg

PaCO2 = 40 mmHg

Blood Values Tissues

PtO2 = 40 mmHg

PtCO2 = 45mmHg

Blood Values Veins

PvO2 = 40 mmHg

PvCO2 = 45mmHg

Blood Values Alveoli

PaO2 = 110 mmHg

PaCO2 = 40 mmHg

Oxygen Saturation SpO2

Measure of Oxygenation at the tissue level measures the % of hemoglobin saturated with O2

How does a pulse oximeter work

2 infrared wavelengths are sent through arterial bed, a photodetector measures the amount of red light that passed through vs absorbed and records data on a plethysmograph

Issues with Pulse Oxyimetry

Affected by: movement, Anemia, Venous Pulsations, CO poisoning, Low perfusion, Nail polish, Edema, Ambient light

Normal SpO2

95%

Cyanosis SpO2

80%

O2 Administration

Titrate to 92-96%

O2 Administration COPD

Titrate to 88-92%

Situations that require High-Flow O2 regardless of SpO2 reading

CO/Cyanide poisoning, Upper Airway Burns, Scuba Diving Accidents, VSA’s and airway obstructions, Sickle Cell disease

HCO3 CO2 %

60%

Hemoglobin CO2 %

30%

CO2 % dissolved in plasma

10%

What compound collects the most CO2 out of the body

HCO3 Bicarbonate 60%

Cheoreceptors sense changes in

CO2, pH+, O2

Central Chemoreceptors

Neurons in the Medulla and Oblongata, most sensitive to pH + CO2

Peripheral Chemoreceptors

Neurons in Carotid bodies and Aortic Arch, most sensitive to changes in O2

End-Tidal CO2 (EtCO2)

The amount of CO2 at the end of expiration

Capnography

Waveform

Capnometry

Numerical value

Normal EtCO2

35-45 mmHg

Alkalosis EtCO2

< 35 mmHg hyperventilation

Acidosis

> 45mmHg Hypoventilation

EtCO2 Factors

• CO2 Production

• Blood Flow Back to Heart

• Alveolar Ventilation

Phase 1

Respiratory Baseline (Dead Air) 

Phase 2

Expiratory Upstroke (Beginning of Exhalation)

Phase 3

Expiratory plateau (exhalation)

Phase 0

Inhalation

EtCO2

Peak of expiratory plateau

Sudden Drop in EtCO2

• Equipment Failure

• Disconnection of ventilator

• Choking

Gradual Drop in EtCO2

• Hyperventilation

• Cardiac Arrest 

• Sudden onset of hypotension 

Sudden Rise in EtCO2

• ROSC

• Release of tourniquet

• Increase in BP

• Increase in Body Temp

• Ventilation of previously unventilated lung

Gradual Rise in EtCO2

Hypoventilation (retaining CO2)

Shark Fin EtCO2

• Bronchocontriction

• Air Trapping

• Indicates need for bronchodilators

EtCO2 for COPD/Asthmatic Patients

Maintain 50-60 mmHg

EtCO2 for Head Injuries

35-45 mmHg

EtCO2 for Herniation

30-35 mmHg

SA Node

Sino-Atrial Node sets the pace (fastest rate)

AV Node

Delays the signal so left atrium pumps after right atrium

Bundle of His

Signal Super-highway, sends signals to purkinje fibers and responisble for how narrow QRS 

Purkinjie Fibers

Rapidly send signals through the ventricles 

SA Node BPM

60-100 BPM

AV Node BPM

40-60 BPM

Perkinjie Fibers BPM

20-40 BPM

ECG

Electrocardiogram, records electrical activity of the heart

P-Wave

Atrial Depolarization

PR Interval

Impulse Travelling from SA-AV

QRS Complex

Ventricular Depolarization

T-Wave

Ventricular Re-polarization

P-wave interval

< 0.12s or < 3 squares

PR Interval

< 0.2s or 1 big Square

QRS Complex Interval

0.08s - 0.1s or 2-3 small squares

Electrode Limb Lead Placement

• White is right

• Snow over Grass

• Smoke over fire

ECG Determination

• Rate

• Rhythm (regular/Irregular)

• Waves (P-wave before every QRS and QRS after every P)

• Intervals (Are they all the same)

• Name it (Sinus)

How to determine the rate on a 6s strip

Count the number of QRS Complexes x10

Narrow QRS Complex

Electrical signal made it down super-Highway

Wide QRS Complex

Electrical Signal Stuck at Perkinjie fibers