Oxygen

FIO2

• fraction of inspired oxygen

• Room air contains about 21% oxygen, so a patient breathing on their own without supplemental oxygen has an FiO2 of approximately 21%

SpO2

• oxygen saturation of peripheral blood

• pulse ox, 95%-100%

• The estimated percentage of oxygen bound to hemoglobin in the arterial blood, as measured by a pulse oximeter. 

SaO2

• the measurement of arterial oxygen saturation, representing the percentage of hemoglobin in your arterial blood that is bound to oxygen.

• The percentage of oxygen bound to hemoglobin in the arterial blood. It is a direct measurement obtained through an arterial blood gas (ABG) test. 

• a normal level is typically 95–100%

PaO2

partial pressure of oxygen in arterial blood

PaCO2

partial pressure of carbon dioxide in arterial blood

adventitious sounds

rhonci, wheezing, crackles

upper respiratory tract

nasopharynx, ornopharynx, laryngeal pharynx

lower respiratory tract

lungs, bronchi, bronchioles, alveoli

medulla oblongata

controls rate and depth of respirations

inspiratory medullary center

deep, prolonged inspiration

respiratory system function

oxygen transport, ventilation, pulmonary diffusion & perfusion

oxygen transport

availability and ability of hemoglobin to carry oxygen from alveoli to cells and CO2 from cells to alveoli to be eliminated

ventilation

movement of air in and out of lungs; occurs through movement of the walls of thoracic cage and diaphragm

lung compliance

ease with which lungs can be inflated

pressure

• varying changes in lung pressure and resulting lung compliance

• a stiff, noncompliant lung requires more effort to inflate

airway resistance

results from obstruction (secretions, foreign substances, tumor, edema) that air meets as it moves through airway

pulmonary diffusion

the movement of gases (oxygen and carbon dioxide) across the alveolar-capillary membrane in the lungs

pulmonary perfusion

the flow of blood through the pulmonary capillaries of the lungs to enable gas exchange; blood flow through pulmonary vasculature

V/Q (ventilation/perfusion) rate

0.8:1.2

partial pressure of gases

• oxygen diffuses across alveolar membrane to dissolve in the blood

• CO2 diffuses out of venous blood into alveolar gas

oxyhemoglobin dissociation curve

relationship between PaO2 and percentage of SaO2

CO2 transport 

• amount of CO2 in transit

• major determinant of acid-base balance

assessment for respiratory system

work of breathing, O2 saturation, thoracic expansion, lung sounds

Infants & Peds— Respiratory

• infants chests are small, airway is short, aspiration can be a problem, respiration is rapid, pulse is rapid

• pediatrics= bronchi and bronchioles are elongated, blood vessels widen and increase in length, BP increases

Gerontologic considerations

• aging decreases respiration function

• decrease in arterial O2 values

• increase risk of pneumonia

• increase risk of aspiration

• aging can affect comfort needs

patients at risk for impaired gas exchange

• smoking & alcohol use disorder

• age

• environment

tidal volume

total amount of air inhaled and exhaled with one breath during normal breathing

minute volume

total volume of air inhaled and exhaled from lungs in one minute (TV x respiratory rate)

vital capacity

max amount of air exhaled after max inspiration

inspiratory force

max strength of inspiratory muscles (diaphragm)

Care of Patient Receiving Oxygen Therapy

• Assess
• Pulse ox
• Color
• Use of accessory muscles
• Monitor ABG's
• Change cannula (hospital policy)
• Use of cotton/gauze comfort
• Good skin care
• Comfort level
• Monitor mucous membranes

allen test

a medical procedure used to assess the blood flow to the hand through the radial and ulnar arteries

pH levels

7.35-7.45

PaCO2 levels

35-45 mmHg

PaO2 levels

80-100 mmHg

HCO3 levels

22-26 mEq/L

O2 stats

95-100%

Pulmonary Function Tests

• measures how much air moves in and out of lungs

• evaluation of flow limitations and airway inflammation

• assess respiratory function or dysfunction

Imaging

• x-ray

• CT

• MRI

• fluoroscopy (series of x-rays for continuous observation flow of barium)

• pulmonary angiography (x-ray and contrast dye to look at blood vessels in lungs)

• lung scan (uses radioactive tracers (gallium) to assess airflow and blood flow in lungs to detect pulmonary embolism)

endoscopic procedures

• bronchoscopy

• thoracoscopy (looks at the inside of the chest cavity)

• biopsy

• lymph node bipsy

Hypoxia

inadequate amount of O2 supplied to the body’s tissues

manifestations of hypoxia

Early

• Tachypnea

• Tachycardia

• Restlessness, anxiety, confusion

• Pale skin, mucous membranes

• Elevated blood pressure

• Use of accessory muscles, nasal flaring, adventitious lung sounds​​​​​​​

Late

• Stupor

• Cyanotic skin, mucous membranes

• Bradypnea

• Bradycardia

• Hypotension

• Cardiac dysrhythmias

hypoxemia hypoxia

low level of oxygen in the blood

circulatory hypoxia

inadequate oxygen due to inadequate blood flow

anemic hypoxia

a condition where the blood does not have enough oxygen-carrying capacity to meet the body's needs. This occurs when there is a decrease in the number of red blood cells or the amount of hemoglobin in the blood

histotoxic hypoxia

body tissues cannot utilize oxygen efficiently even with adequate O2 delivery

oxygen toxicity

results from high concentration of oxygen or long durations of oxygen therapy (24-48 hours)

nursing actions for oxygen toxicity

use lowest level of O2, monitor ABG, decrease FiO2 as SpO2 improves, assess for symptoms

• To decrease FiO2, a healthcare provider will gradually lower the oxygen level to the patient's target, typically using a range of 1%-10% increments while monitoring their blood oxygen saturation

symptoms of oxygen toxicity

cataracts, visual field loss, near sightedness, bleeding, twitching, seizures, coughing, shortness of breath, substernal pain, nausea, vomiting, fatigue, dyspnea, restlessness

medulla

• part of the brain responsible for the rate and depth of respirations

• part of the brain responds to levels of C02 to initiate a breath

low flow O2 administration

• nasal cannula, simple mask, partial rebreather mask, non-rebreather mask, oropharyngeal catheter

• less than or equal to 6 L/min

high flow O2 administration

venturi mask, aerosol mask, face tent, tracheostomy collar/T-piece

nasal cannula (low flow)

Delivers an FiO₂ of 24% to 44% at a flow rate of 1 to 6 L/min.

Advantages

• A safe, simple, and easy-to-apply method.

• Is comfortable and well-tolerated.

• The client is able to eat, talk, and ambulate.

Disadvantages

• The FiO₂ varies with the flow rate, and the rate and depth of the client’s breathing.

• Extended use can lead to skin breakdown and dry mucous membranes.

• Tubing is easily dislodged.​​​​​​​

Nursing Actions

• Assess the patency of the nares.

• Ensure that the prongs fit in the nares properly.

• Use water-soluble gel to prevent dry nares.

• Provide humidification for flow rates of 4 L/min and greater.

Simple Face Mask (low flow)

Covers the client’s nose and mouth

Fraction of Inspired Oxygen

• It delivers an FiO₂ of 35% to 50% at flow rates of 5 to 10 L/min.

• The minimum flow rate is 5 L/min to ensure flushing of CO₂ from the mask.

Advantages

• Easy to apply and can be more comfortable than a nasal cannula.

• It is a simple delivery method.

• It is more comfortable than a nasal cannula.

• It provides humidified oxygen.

Disadvantages

• Flow rates less than 5 L/min can result in rebreathing of CO₂.

• Clients who have anxiety or claustrophobia do not tolerate it well.

• Eating, drinking, and talking are impaired.

• Moisture and pressure can collect under the mask and cause skin breakdown.

• Face masks pose a greater risk of aspiration.

Nursing Actions

• Assess proper fit to ensure a secure seal over the nose and mouth.

• Make sure the client wears a nasal cannula during meals.

• Use with caution for clients who have a high risk of aspiration or airway obstruction. 

• Monitor for skin breakdown.

Partial rebreather mask (low flow)

Covers the client’s nose and mouth

Fraction of inspired oxygen: Delivers an FiO₂ of 60% to 80% at flow rates of 6 to 10 L/min.

Advantages

• The mask has a reservoir bag attached with no one-way valve, which allows the client to rebreathe up to ⅓ of exhaled air together with room air.

• Allows easier humidification of oxygen.

Disadvantages

• Complete deflation of the reservoir bag during inspiration causes CO₂ buildup.

• The FiO₂ varies with the client’s breathing pattern.

• Clients who have anxiety or claustrophobia do not tolerate it well.

• Eating, drinking, and talking are impaired.

• The bag can twist or kink easily.

Nursing Actions

• Keep the reservoir bag from deflating by adjusting the oxygen flow rate to keep the reservoir bag ⅓ to ½ full on inspiration.

• Assess proper fit to ensure a secure seal over nose and mouth. Assess for skin breakdown beneath the edges of the mask and bridge of the nose.

• Make sure the client uses a nasal cannula during meals.

• Use with caution for clients who have a high risk of aspiration or airway obstruction

Non-rebreather mask (low flow)

Covers the client’s nose and mouth

Fraction of inspired oxygen: Delivers an FiO₂ of 80% to 95% at flow rates of 10 to 15 L/min to keep the reservoir bag ⅔ full during inspiration and expiration.

Advantages

• It delivers the highest O₂ concentration possible (except for intubation).

• A one-way valve (difference from partial) situated between the mask and reservoir allows the client to inhale maximum O₂ from the reservoir bag. The two exhalation ports have flaps covering them that prevent room air from entering the mask.

Disadvantages

• The valve and flap on the mask must be intact and functional during each breath.

• It is poorly tolerated by clients who have anxiety or claustrophobia.

• Eating, drinking, and talking are impaired.

• Use with caution for clients who have a high risk of aspiration or airway obstruction.

Nursing Actions

• Perform an hourly assessment of the valve and flap.

• Assess proper fit to ensure a secure seal over the nose and mouth. Assess for skin breakdown beneath the edges of the mask and bridge of nose.

• Make sure the client uses a nasal cannula during meals.

Venturi Mask (high flow)

Covers the client’s nose and mouth

Fraction of inspired oxygen: Delivers an FiO₂ of 24% to 60% at flow rates of 5 to 10 L/min via different size adapters, which allows specific amounts of air to mix with oxygen.

• 2 L/min=24% FiO2

• 4 L/min=28% FiO2

• 8 L/min=35% FiO2

• 10 L/min= 40% FiO2

• 15 L/min=60% FiO2

Advantages

• It delivers the most precise oxygen concentration with humidity added.

• Best for clients who have chronic lung disease.

Disadvantages

• Use is expensive.

• Eating, drinking, and talking are impaired.

• The mask and added humidity can lead to skin breakdown.

Nursing Actions

• Assess frequently to ensure an accurate flow rate.

• Assess proper fit to ensure a secure seal over the nose and mouth. Assess for skin breakdown beneath the edges of the mask, particularly on the nares.

• Make sure the tubing is free of kinks.

• Ensure that the client wears a nasal cannula during meals

aerosol masks (high flow)

Types: face tent and tracheostomy collar

Fraction of Inspired Oxygen

• Delivers an FiO₂ of 24% to 100% at flow rates of at least 10 L/min.

• Provides high humidification with oxygen delivery.

Advantages

• Use with clients who do not tolerate masks well.

• Useful for clients who have facial trauma, burns, and thick secretions.

Disadvantages: High humidification requires frequent monitoring.

Nursing Actions

• Empty condensation from the tubing often.

• Ensure adequate water in the humidification canister.

• Ensure that the aerosol mist leaves from the vents during inspiration and expiration

• Make sure the tubing does not pull on the tracheostomy.

incentive spirometry

patient inhales deeply, raising piston to goal mark; helps strengthen muscles used for breathing and improve lung expansion, capacity, and function.

chest physiotherapy

• mobilizes pulmonary secretions (includes percussion)

• followed by productive coughing or suctioning

• do not use on patients with head injury, hypotension, hypertension, post-op patients, COPD, and pediatric pneumonia patients.

oxygen therapy

• oxygen is a drug

• ordered in L/min

• indication=hypoxia, hypoxemia 

• goal= PaO2 > 60, SpO2 > 90%

Nursing management for oxygen therapy

• humidify oxygen

• clear oral and nasal secretions

• check O2 levels

• watch for toxicity

• restrict smoking

• maintain airway patency

• ensure safe functioning of delivery system

artificial airways

• pharyngeal airways

• prevent tongue from obstructing upper airway

• Oropharyngeal airway

• Nasopharyngeal airway (you can suction at opening)

endotracheal tubes

• oral and nasal

• used when upper airway has obstruction

• x-ray to make sure its placed properly

• have cuffs that you have to keep inflated and at an exact pressure with water or air (20-30 cm)

endotracheal tube complications

• tube obstruction

• tube displacement

• Sinusitis and nasal injury

• Tracheoesophageal fistula

• Mucosal lesions

• Laryngeal or tracheal stenosis (narrowing)

• Cricoid abscess (rare infection, usually in children, s/s=stridor)

tracheostomy

• Preferred for long-term intubation

• If patient intubated with ETT for more than 7-10 days

• Upper airway obstruction due to trauma, tumors, or swelling

• Neuromuscular diseases

• this procedure can be done in an OR and at the bedside

• keep site clean and dry; skin moist

• suction if patient can’t cough

suctioning

• takes away air, no more than 80-120 mmHg for 10-15 secs (3x max)

• Hyperoxygenation

• Hyperinflation

• Catheter external diameter size

Ventilators

• positive pressure

• negative pressure (iron lung, non-invasive)

• have to wean someone off to see if patient can tolerate; never wean at night

• ABG’s, auscultate lung, look for muscular fatigue

weaning methods for ventilators

• T-piece

• SIMV (a mode of mechanical ventilation where a ventilator delivers a set number of mandatory breaths, while also allowing the patient to take spontaneous breaths)

• PSV (a mode of mechanical ventilation where the ventilator assists the patient's own breathing with a preset pressure to support spontaneous breaths)

ventilator complications

impaired venous return to right side of heart, gastric distension, and “bucking” (ventilator is pushing air in and person tries to push it out—usually a sign that a patient is ready to be taken off the ventilator). 

ventilator protocol

• hand hygiene

• oral care every 12 hours which prevents ventilator assisted pneumonia (which has a 20%-50% mortality)

• keep head elevated

• remove mucus every 2 hours

Nursing Management of Patient a Ventilator

• Pulmonary assessment

• Arterial blood gas assessment

• Manual rebreather mask at bedside for emergencies

• Monitor for respiratory muscle fatigue

• Educate patient (if appropriate) and family about function of mechanical ventilation

non-invasive mechanical ventilation

• CPAP

• Biphasic positive airway pressure (Increasing the pressure in the airways during inspiration, which helps to open up collapsed airways and improve oxygenation; providing a lower pressure during expiration, which allows for easier exhalation and reduces the work of breathing).

absorption atelectasis

A condition where alveoli (tiny air sacs in the lungs) collapse due to the absorption of gases into the bloodstream.

Home Oxygen Therapy

• do not put oxygen tank in corner

• notify fire department because oxygen is flammable

• make sure smoke detectors work

• keep tubing away from electrical cords

extubation/decannulation

• At bedside

• Instruct patient about the procedure

• Hyperoxygenate

• Suction trachea (then oral airway)

• Deflate cuff

• Administer oxygen

• Monitor vital signs