ARF Flashcards
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
ACUTE RESPIRATORY FAILURE
ARF is an umbrella term.
Results from one or more diseases involving the lungs or other body systems.
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
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)
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
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
VQ Mismatch is where
you don’t have enough perfusion or gas exchange to a lung area.
Common causes of V/Q Mismatch - on test - just 1 disease - the big one
PNA
V/Q - WHAT IS OBSTRUCTED: (2 things)
VENTILATION (AIR) OR PERFUSION (BLOOD FLOW)
ARDS
V/Q Mismatch because Fluid leaks out from the capillary into the alveoli
SHUNTS - what happens?
Blood passes through the lungs or heart without being oxygenated.
Two types of Shunts (shunts are AI)
ANATOMICAL
INTRAPULMONARY
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.
Intrapulmonary Shunts
(intra V/Q)
this is the same as a VQ mismatch -
Either alveoli is plugged or blood vessel is plugged
Shunt ex: bld vessel plugged (literally a blood plug)
(PE)
Shunt: Airway plugged
(plugged pna)
(PNA)
DIFFUSION LIMITATION
(diffusely thick)
Alveolar-capillary membrane is thickened, destroyed or fibrotic
ALVEOLAR HYPOVENTILATION - what is altered?
(Alf drives)
Respiratory drive is altered
There are two types of ARF - just 1 and 2
TYPE I
Type II
TYPE I (Hypoxemic respiratory Failure)
(type A is alvin and pulmonary)
Oxygen failure
Inadequate transfer of 02 between alveoli and pulmonary capillary bed
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
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
Causes of Hypercapnia ARF - Four Categories (hyper respiratory is central to my chest muscles)
Respiratory (airway/alveoli)
Central Nervous System
Chest Wall
Neuromuscular
HYPERCAPNIC RESPIRATORY FAILURE - RESPIRATORY CAUSES (3 things - just think lung disease) - what about CF?
Airflow obstruction and trapping - ex.
Asthma
COPD (Emphysema)
Cystic Fibrosis
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