O2 Therapy & Air way management techniques

Abdualrahman ALshehri

Lecturer

King Saud University

Riyadh Community College

RN, MSN

Respiratory Anatomy

Nose and mouth (warms, moistens, and filters air).

Pharynx

–Oropharynx

–Nasopharynx

Epiglottis

Trachea (windpipe)

Respiratory Anatomy

Cricoid cartilage (adams apple).

Larynx (voice box).

Bronchi

Lungs

–Visceral pleura (surface of lungs)

–Parietal pleura (internal chest wall)

–Interpleural space (potential space)

Respiratory Anatomy

Diaphragm

Inhalation (active process)

–Diaphragm and intercostal muscles contract, increasing the size of the thoracic cavity.

–Diaphragm moves slightly downward, ribs move upward and outward.

Air flows into the lungs creating a negative pressure in the chest cavity.

Respiratory Anatomy

Exhalation (passive process)

Diaphragm and intercostal muscles relax decreasing the size of the thoracic cavity.

–Diaphragm moves upward, ribs move downward and inward.

Air flows out of the lungs creating a positive pressure inside the chest cavity.

Respiratory Physiology

Oxygenation - blood and the cells become saturated with oxygen

Hypoxia - inadequate oxygen being delivered to the cells

Signs of Hypoxia

– Increased or decreased heart rate

– Altered mental status (early sign)

– Agitation

– Initial elevation of B.P. followed by a decrease

– Cyanosis (often a late sign)

Alveolar/Capillary Exchange

Oxygen-rich air enters the alveoli during each inspiration.

Oxygen-poor blood in the capillaries passes into the alveoli.

Oxygen enters the capillaries as carbon dioxide enters the alveoli.

Capillary/Cellular Exchange

Cells give up carbon dioxide to the capillaries.

Capillaries give up oxygen to the cells.

Functions of the Respiratory System: Overview

Exchange O2

–Air to blood

–Blood to cells

Exchange CO2

–Cells to blood

–Blood to air

Regulate blood pH

Vocalizations

Protect alveoli

Factors Affecting Ventilation

Airway Resistance

Diameter

Mucous blockage

Bronchoconstriction

Bronchodilation

Alveolar compliance

1. Surfactants

2. Surface tension

Alveolar elasticity

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Gas Exchange in the Alveoli

Thin cells: exchange

Surfactant cells

Elastic fibers

– Recoil

– Push air out

Thin basement membrane

Capillaries cover 90% of surface

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Gas Exchange in the Alveoli

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Oxygen movement

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Oxygen movement

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Oxygen movement

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Oxygen Therapy

For over 200 years oxygen therapy has often been used and sometimes misused (Hough 2001)

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Oxygen Therapy

Should be prescribed

Acute and chronic respiratory conditions

Personnel should be trained in its use

Protocols

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Oxygen Therapy - Indications

Hypoxaemia (PaO2<8KPA, O2sats<90%)

Acute or chronic respiratory condition

Pre and post suction

Routinely post operatively

Optimise oxygen delivery

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Oxygen therapy - limitations

Giving oxygen does not guarantee it’s arrival at the mitochondria

Oxygen does not improve ventilation directly

(Hough 2001)

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Oxygen therapy – complications/cautions

Respiratory depression if hypoxic drive

Pulmonary oxygen toxicity

Tracheobronchitis

Absorption atelectasis

Fire

Variable delivery

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Oxygen Therapy - Monitoring

Oxygen saturations continuous/intermittent

Arterial blood gases

Observation

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Oxygen therapy – delivery devices

Low Flow masks (variable performance)

High flow masks (fixed flow)/venturi

Nasal cannulae

Mask and reservoir bag

Tracheal mask/t-piece

Tracheal speaking valves

Mechanical ventilator

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Oxygen Therapy - low flow masks

Commonly used

Variable performance

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Oxygen therapy – high flow masks

Guaranteed percentage of oxygen

Venturi system

More expensive

Up to 60%

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Nasal cannulae

1l/min 24% oxygen

2l/min 28% oxygen

3l/min 32% oxygen

4l/min 36% oxygen

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Oxygen therapy – bag and mask

High concentrations of oxygen

Mask and reservoir bag

55-90%

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Oxygen Therapy tracheostomy

T-piece

Mask

Swedish nose

Speaking valve

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Long term oxygen therapy

Chronic hypoxaemia

Increases survival

Aim to raise PaO2 to >8Kpa

Worn as much as possible >15hours

Cylinders/concentrators/liquid

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Humidification

Mucocillary escalator

Adequate hydration is vital

Bacterial contamination!!!

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Humidification - indications

URT bypassed

Thick retained secretions

High flow oxygen/non-invasive mechanical aids

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Humidification - Cautions

Hyper-reactive airways - bronchospasm

Infection

Burns

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Humidification - Types

Nebulisers Large/Small/Ultrasonic

Steam

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Humidification - Humidifiers

Hot - Increases moisture content

- Increases risk of infection

Cold - Poor moisture content

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Non-invasive ventilation

BiPAP

CPAP

IPPB

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