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*In preparation for exam II MDCIV*.
Module 05
Acute respiratory failure:
What is it? Critical Values Remember
• A mismatch of ventilation (V) or o ABG - PaO2 o Ventilation = air movement (V)
perfusion (Q), or a combination of -
Result: Less than 60 mm Hg
both. o ABG - PaCO2 o Perfusion = blood flow (gas
• When there is a VQ mismatch, gas - Result: Greater than 45 mm Hg exchange) (Q)
exchange is decreased, resulting in o ABG – pH
respiratory failure. - Result: <7.35
• ABGs are ordered to evaluate the o ABG - SaO2
pts. gas exchange anticipating that - Result: Less than 90%
the client is hypoxemic.
Ventilatory Failure:
Causes: Example: Drug OD continues to rise in the US to epidemic levels as reported by the
CDC. Fentanyl is quickly rising as the drug of choice among abusers. Fentanyl is a
• Neuromuscular disorders. potent opioid either RX or manufactured illegally. Fentanyl can quickly depress the
• Central nervous system respiratory system. In this example, there is nothing mechanically wrong with the
dysfunction. lungs, no V/Q mismatch. Without the drug in the pts. body, the lungs would perform
• Chemical depression. both ventilation and perfusion normally. However, as the drug depresses the central
nervous system, it depresses the drive to breathe (V), which then slows perfusion (Q).
During an OD, breathing ceases completely as the client slips into unconsciousness. In
this example, the pt. has a V/Q mismatch and a resulting respiratory failure.
Recognizing Symptoms:
Evaluating compromised respiratory status: Dyspnea (S/S of respiratory failure)
• A way to evaluate compromised respiratory
status is to assess for SOB (dyspnea) while • Occurs when the pt. is no longer able to lay flat in a bed which is also
the pt. is performing everyday tasks. known as orthopnea.
• The common term used to describe the • This pt. will find it easier to rest or sleep in an upright position.
work of breathing while performing a task Clinically, the PCP will monitor for hypercapnia and hypoxia by
is dyspnea on exertion (DOE). monitoring Arterial Blood Gases (ABG).
• S/S of hypoxic respiratory failure. *Be Hypercapnia
aware as nurse*
• Different S/S, but the same end result of respiratory failure can occur.
o Restlessness Understand the difference between hypoxia and hypercapnia. The
o Irritability S/S are as follows:
o Agitation
o Confusion o Decreased level of consciousness (LOC)
o Tachycardia o Headache
o Drowsiness
o Lethargy
o Seizures
, Acidosis Oxygenation as Early Intervention
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The onset of acidosis is associated with respiratory • The goal is to maintain the PaO2 level above 60 mm Hg and
failure. treat the underlying cause.
• Depending on the urgency and how quick the onset of
S/S of acidosis include: respiratory failure occurs determines the aggressiveness of
the treatment.
o Decreased LOC • If the situation allows, start with oxygen delivered by nasal
o Drowsiness cannula or mask.
o Confusion • The next, more aggressive, intervention would be the use of
o Hypotension BiLevel Positive Airway Pressure (BiPAP). This is a non-
o Bradycardia invasive approach to forcing air into the lungs to improve
o Weak peripheral pulses oxygenation (gas exchange).
• The invasive procedure of endotracheal intubation with
mechanical ventilation is utilized as a last resort.
Additional Interventions to open the airway: Other interventions to allow for maximum lung expansion:
• Nebulizer tx which is administered to dilate the • Place the pt. semi-high Fowler’s position.
bronchioles and promote gas exchange. • Stay calm: If you are anxious, the client will become
• This can be administered while the pt. is using either anxious and use more energy to breathe.
oxygen or BiPAP. • Consider holding off on any unnecessary procedures that
cause energy expenditures.
Further intervention is determined by:
• Identifying the underlying cause of impending respiratory failure.
• Once the cause is determined, then a clear course of treatment is developed.
• The nurse may administer corticosteroids, antibiotics, diuretics, analgesics, or antianxiety
medications. The nurse should continue to monitor the pt. closely.
Acute respiratory distress syndrome:
What is it? Key features of ARDS:
• A life-threatening disorder that may cause permanent • A hallmark sign is hypoxemia that persists even when
damage to the lungs. 100% oxygen is given, which is known as refractory
hypoxemia.
Mortality rate:
• Decreased pulmonary compliance (elasticity)
• There is a high mortality rate associated with ARDS. • Lowered production of surfactant
• The occurrence of ARDS is associated with acute lung • Dyspnea
injury (ALI) in people without pulmonary disease. • Noncardiac-associated bilateral pulmonary edema
• As the nurse, pay close attention to oxygenation (gas • Dense pulmonary infiltrates on x-ray known as ground-
exchange). glass appearance.