nurs 411: oxygenation and gas exchange

perfusion

oxygenating blood

ventillation

inhale + exhale

hypoxemia

blood oxygen levels

hypoxia

-lack of oxygen at cellular level

-decreased amount of oxygen in tissues

-linked to anemia and poor oxygen/ CO2 diffusion

hypoxia etiology/ risk factors

-smoke inhalation

-high altitudes

-lung diseases: COPD, pneumonia, asthma

-medications that suppress or decrease respiratory rate

-anemia

hypoxia clinical manifestations

*****RESTLESSNESS: THINK OXYGEN ISSUES FIRST

-especially significant in kids

hyperventilation

**breathing too fast -> blowing off CO2

**alkalosis

-increase in rate of depth of breathing

-low carbon dioxide levels in the blood

hyperventilation s/s

-weakness

-dizziness

-headache

-anxiety

-tachycardia

-numbness

-tingling of extremities

hyperventilation etiology

-anxiety attacks

-infections (eg. pneumonia)

-lung disease (eg. COPD, asthma)

-diabetic ketoacidosis

-brain injury

hypoventilation

-acidotic -> holding on to CO2

-shallow breathing with low respiratory rate

-elevated CO2 levels -> increase of carbonic acid in the blood

hypoventilation s/s

-anxiety

-dyspnea with exertion

-confusion

-disturbed sleep patterns

-weakness

-poor cough

hypoventilation etiologies

-neuromuscular disorders (muscular dystrophy, guillain-barre syndrome)

-mediations (barbiturates, narcotics, benzodiazepines)

-neurologic disorders

-trauma

nasal cannula flow rate/ concentration

flow rate: 1-6 L/min

-suitable for low-flow therapy

-delivers: 24%-44% oxygen

*not exact

nasal cannula advantages

-safe, simple, cheap

-comfort & compliance

-decreased likelihood of causing claustrophobia

-allows patient to eat and drink without removing oxygen

-avoids rebreathing of CO2

nasal cannula disadvantage

-headaches and dry mucous (if flow > 4 L/min)

-dermatitis and nasal irritation

-nor recommended for clients with nasal obstructions such as polyps and mucosal edema

simple face masks flow rate & concentration

-flow rate: 5 to 8 L/min

-concentration: 40%-60% oxygen (medium concentration, higher than nasal cannula)

-constant rate

***dependent on pt depth and rate of breathing

simple face mask advantages

-cheaper

-good for mouth breathers

-suitable for short term oxygen administration

simple face masks disadvantages

-claustrophobia

-CO2 retention with exhalation

-interferes with eating and talking

**not recommended for clients who retain carbon dioxide (COPD)

***ASPIRATION RISK!! use with caution for patients who have nausea/ vomiting

**if pt is not fully awake and vomits into mask, it creates a risk of aspiration and airway obstruction

venturi mask flow rate/ concentration

-flow rate: 4 to 10 L/min

-oxygen concentration: delivers 24% to 50%

***mask has holes that deliver oxygen at high velocity mixed along with room air

venturi mask function

-provides exact/precise amount of oxygen

-venturi barrels can be exchanged to change and deliver various specific oxygen concentrations

**does not need to rely on patient's strength of respiratory effort

venturi mask advantages

-decreases rebreathing of exhaled air

****ideal for COPD patients

venturi mask disadvantages

-noisy

-claustrophobic

-interferes with eating and drinking

non-invasive ventilation

-delivers oxygen and positive pressure directly into the patients airway using a tight-fitting mask rather

-helps push oxygen through the airway to meet oxygen needs and can be used during day and night

-avoids placing patient on invasive ventilator

CPAP (continuous positive airway pressure)

-delivers continuous, constant positive airway pressure

***primarily used for obstructive sleep apnea (OSA)

clinical signs of OSA

-morning headache

-extreme daytime drowsiness

-loud snoring

-restlessness

CPAP considerations

-patients have to bring into hospital if they are on it at home and want meds or surgery!!

BiPAP (bilevel positive airway pressure)

-delivers oxygen under varying/two levels of pressure

-higher set pressure for inhalation and lower pressure for exhalation

***good for COPD exacerbations

-can help manage severe respiratory compromise + extend lives

Partial Re-Breather

-attached reservoir bag but no one-way valve

-oxygen is delivered at a higher flow rate and at a higher concentration

-exhaled air enters the bag and exits through open side holes in the mask, when the client inhales again, oxygen and exhaled carbon dioxide mix

**bag must remain inflated to prevent the client from retaining too much CO2

Non-Rebreather (NRB) mask

-constructed just like the partial rebreather except for the presence of one-way valves over the exhalation ports and between the mask and reservoir bag

-the valves ensure exhaled gases are not returned to the bag completely preventing the patient from breathing exhaled carbon dioxide

-the reservoir bag supplies the inhaled oxygen and should NOT completely collapse on exhalation

-not safe for long-term use in COPD or respiratory failure due to risk of oxygen toxicity

acute oxygen toxicity

-primarily affects the CNS

-muscle twitching

-nausea

-convulsions

-dysphoria

-tinnitus

chronic oxygen toxicity

-primarily impacts the pulmonary system

-atelectasis (alveolar collapse)

-coughing

-dyspnea

-chest pain substernal pain

interventions

-Incentive spirometry: used for atelectasis prevention (keeping alveoli open)

-Chest physiotherapy: involves percussion, vibration, and postural drainage to mobilize pulmonary secretions

***Pursed- Lip Breathing: specifically used for COPD patients to prolong exhalation, prevent air trapping