ARF Flashcards by Amanda S.

Function of Respiratory System

Gas exchange of oxygen and carbon dioxide from the atmosphere and the blood.

GASES:
O2 and CO2
Oxygen and Carbon Dioxide

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ACUTE RESPIRATORY FAILURE

ARF is an umbrella term.
Results from one or more diseases involving the lungs or other body systems.

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ARF is a characterized by (2 things)

Respiratory systems inability to supply sufficient oxygen (O2) to the tissues

or to eliminate carbon dioxide (CO2) from the bloodstream

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DIAGNOSTIC CRITERIA FOR ARF - think hypercapnic or hypoxic

(alf is now 45)

PaO2 < 60 while receiving > 60% oxygen (normal range PaO2 75 – 100)
OR →
PCO2 > 45 with pH < 7.35 (acidic)
(normal PCO2 range 35 – 45)

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FOUR MECHANISMS that cause Hypoxemic and Hypercapnic ARF

(Alf SHVD ARF, he’s causing it!)

VQ (ventilation-perfusion) MISMATCH
SHUNT (Type of VQ mismatch)
DIFFUSION LIMITATION
HYPOVENTILATION

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normal V/Q ratios

Normally the volume of blood pumped thru the lungs each minute is about 4 – 5 L.
The volume of air in and out of the lungs each minute is about 4 –5 L
1ml of air to 1 ml of blood / each lung unit.
This would result in a V/Q ratio of 1:1 - this is what we want

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VQ Mismatch is where

you don’t have enough perfusion or gas exchange to a lung area.

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Common causes of V/Q Mismatch - on test - just 1 disease - the big one

PNA

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V/Q - WHAT IS OBSTRUCTED: (2 things)

VENTILATION (AIR) OR PERFUSION (BLOOD FLOW)

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ARDS

V/Q Mismatch because Fluid leaks out from the capillary into the alveoli

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SHUNTS - what happens?

Blood passes through the lungs or heart without being oxygenated.

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Two types of Shunts (shunts are AI)

ANATOMICAL
INTRAPULMONARY

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Anatomical Shunt

(anatomically passing me by on the right side)

Blood passes from the right side of the heart to the left without being oxygenated.

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Intrapulmonary Shunts

(intra V/Q)

this is the same as a VQ mismatch -
Either alveoli is plugged or blood vessel is plugged

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Shunt ex: bld vessel plugged (literally a blood plug)

(PE)

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Shunt: Airway plugged

(plugged pna)

(PNA)

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DIFFUSION LIMITATION

(diffusely thick)

Alveolar-capillary membrane is thickened, destroyed or fibrotic

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ALVEOLAR HYPOVENTILATION - what is altered?

(Alf drives)

Respiratory drive is altered

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There are two types of ARF - just 1 and 2

TYPE I
Type II

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TYPE I  (Hypoxemic respiratory Failure)

(type A is alvin and pulmonary)

Oxygen failure
Inadequate transfer of 02 between alveoli and pulmonary capillary bed

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CAUSES OF
hypoxemic ARF AND SAME FOR V/Q MISMATCH - know these!

(I need an ARF and glen APPP)

ARDS
PNA
Pulmonary Edema
Pulmonary Emboli
KNOW THESE

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Type II  (Hypercapnic respiratory failure) - think getting co2 out

Ventilatory failure– problem with inhalation/exhalation process
Respiratory system can’t ventilate out enough CO2 to maintain a normal Co2 level

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Causes of Hypercapnia ARF - Four Categories (hyper respiratory is central to my chest muscles)

Respiratory (airway/alveoli)
Central Nervous System
Chest Wall
Neuromuscular

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HYPERCAPNIC RESPIRATORY FAILURE - RESPIRATORY CAUSES (3 things - just think lung disease) - what about CF?

Airflow obstruction and trapping - ex.
Asthma
COPD (Emphysema)
Cystic Fibrosis

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Asthma - breathing?

Bronchospasms, bronchial edema ↑ secretions – obstruct airflow Narrowed Bronchioles Labored breathing

HYPERCAPNIC RESPIRATORY FAILURE - COPD - is it obstructive?

Obstructed airflow

HYPERCAPNIC RESPIRATORY FAILURE - Cystic Fibrosis (fibrosis is stiff)

Stiff lungs and secretions obstruct airflow

Hypercapnic ARF - CNS causes (hyper brain)

Brainstem infarct and (TBI) Traumatic Brain Injury Vital center for respirations compromised

Hypercapnic ARF - CHEST WALL CAUSES (3 things)

this is Dysfunction that limits lung expansion. ex. Flail Chest Kyphoscoliosis Obesity

hypercapnic - Flail Chest - what type of breathing

Mult Fx’d Ribs  Paradoxical Breathing

hypercapnic - Kyphoscoliosis

Kyphoscoliosis Spinal deformities prevents expansion of lungs

Hypercapnia Respiratory Failure Chest wall also caused by (just fat)

Morbid Obesity

Hypercapnic ARF NEUROMUSCULAR CAUSES (alf and AL's muscles are hyper phrantic) - and damage to which nerve?

(Respiratory muscles are weakened or paralyzed) ALS (Amyotrophic Lateral Sclerosis) Phrenic Nerve Injury

S & S of Hypercapnic ARF cont (think apnea and you)

A severe morning headache suggest hypercapnia occurred during the night with an accumulation of CO2 (ACID). train them to do Pursed lip breathing (I:E 1:3) Tripod positioning (high fowlers with arms holding self up)

EARLY SIGNS OF RESPIRATORY FAILURE - behavior? and heart and bp?

Restlessness, confusion agitation from ↓ O2 to the brain. Tachycardia and mild hypertension

Late signs Resp Failure - and what % is PA02 when it occurs? (cyan is 45 yrs old)

Cyanosis occurs when PaO2 is less than 45 mm Hg

DIAGNOSTIC TESTS

ABG’S Pulse ox, O2 saturation CXR PA and Lat V/Q scan Chest CT Blood and Sputum cultures Bronchoscopy Lung Biopsy

TREATMENT OF ACUTE RESP FAILURE - just depends on the cause

Because many different problems can cause ARF, treatment will vary Treat the underlying cause and concurrent medical problems

treatment - Maintain adequate oxygenation and ventilation - what types? (basically all of them)

ADMINISTER O2 Face mask Mechanical Ventilation CPAP (continuous positive airway pressure) BiPAP (Bi-level positive airway pressure)

Mechanical Ventilaton

FIO2 Rate Tidal Volume PEEP (Positive End Expiratory Pressure) ETCO2 end tidal carbon dioxide (indicates adequate ventilation)

CPAP Continuous Positive Airway Pressure - is it expiration or inspiration? (it's in the name)

Delivers positive pressure during inspiration and expiration

BiPAP - high or low during expiration? (bi pap, he's expiring)

Bilevel Positive Airway Pressure Positive Pressure drops during expiration

CAVEAT (caution) OF O2 ADMINISTRATION - and what should the % of O2 administration be? (not 90%)

Oxygen administration >60% can cause O2 toxicity with fibrotic changes in the lungs. Caution in COPD patients Chronic hypercapnia causes CO2 narcosis. Respirations stimulated by low O2 levels. If O2 is suddenly increased pt may go into respiratory arrest.

peep - inspiration or expiration? (it's in the name)

positive end-expiratory pressure (pressure in lungs at end of expiration)

FIO2

fraction of inspired oxygen concentration

V/Q

ventilation/perfusion ratio (relationship of ventilation to perfusion in the lungs) - it should be 1:1

2 types of respiratory failure

hypoxemic and hypercapnic

hypoxemic respiratory failure - what is the number?

oxygen failure PaO2 less than or equal to 60 mm Hg at 60% oxygen

hypoxemic respiratory failure can last how long?

acute (minutes to hours) or chronic (several days or longer)

hypercapnic respiratory failure - the numbers, think CO2

ventilatory failure. PaCO2 greater than 45 mm Hg and ph less than 7.35

hypercapnic respiratory failure can last how long?

acute (minutes to hours) or chronic (several days or longer)

Pulmonary Emboli

Good alveoli (air) - poor perfusion - so ventilation perfusion problem

we can give O2 in an emergency, but

we need to get an order afterwards. O2 is a drug.

normal ABGs

ph 7.35 – 7.45 PaO2 75 – 100 PaCO2 35 – 45 HCO3 22 - 26

common cause of VQ mismatch - fluid? - 3 things (Steven in the hall)

secretions in airways Pulmonary edema Fluid in alveoli

common cause of VQ mismatch - (just emboli)

Pulmonary emboli ↓ perfusion in lung

common cause of VQ mismatch - just 1 (alden is a mismatch)

ARDS (Capillaries leaking fluids into alveoli)

diffusion limitation - caused by (diffuse the fibrosis in alden)

Pulmonary fibrosis ARDS (late stage)

alveolar Hypoventilation caused by 4 diseases - this is broad (3 diseases and 1 other)

Lung disease Neuromuscular disease CNS disease Chest wall dysfunction

ARF - type I (first, you need oxygen)

TYPE I (Hypoxemic respiratory Failure) Decrease in oxygen

ARF - type 2

Type II (Hypercapnic respiratory failure) Increase in carbon dioxide CO2=ACID

type I - Hypoxemic Failure defined as:

PaO2 ≤60 when the pt is receiving FIO2 of ≥60%

hypercapnic ARF - other reasons (drugs)

other reasons - Narcotics, OD, Anesthesia Decreased respiratory rate

type II - hypercapnic - PaCo2? and pH?

CO2 = Carbon Dioxide = ACID Defined as PaCo2 ≥45 with pH ≤7.35 This type almost always also has hypoxemia too.

hypercapnic ARF - neuromuscular causes (think spine and aspirin)

Cervical Cord Injury Guillain-Barre Syndrome

how to titrate paO2 - this is the mask (Alf's oxygen is 55)

Titrate PaO2 at 55 to 60 or O2 sat > 90%.

anatomical shunt - ex. (anatomical babies)

It could be a Patent Ductus Arteriosus (babies) or Ventral Septal Defect (sometimes not identified until teens)

hypercapnic ARF - neuromuscular causes (hyper with MS, MD, and polio)

Poliomyelitis (polio) Muscular Dystrophy Multiple Sclerosis

Sa02

02 sat in arterial blood measured with ABG

how to diagnose ARF?

ABG really helpful

pursed lip breathing

one inhale for every 3 exhales

pulmonary emboli - are the capillaries ok?

yes, but poor perfusion=ventilation perfusion issue