Acute Resp Failure (ARF) Flashcards
(29 cards)
resp failure def
system fail in one or both major function
- gas exchange (oxygenation)
- ventilation (eliminate CO2)
diagnose ARF?
ABGs
PAO2< 60
PaCO2 > 45
pH < 7.35 (for Pts with chronic elevated CO2)
Type 1 resp failure
acute hypoxemic resp failure
- low PaO2
- prob gas exchange**
ex: CHF, atelectasis, fibrosis, pneumonia, decreased CO, hypotension, PE, shock
Type 2 resp failure
acute hypercapnia/hypercarbic resp failure
- high PaCO2
- primary issue ventilation** impacting elimination of CO2
ex. COPD, Guillian Barre, Drug OD, pleural effusions. chest trauma, MS, muscluar dystrophy, asthma, trach obstruction, massive obese,
mixed/combined resp failure
hypoxemic/hypercapnic
- diff to determine primary cause
- if either type left too long, will result in both
type 1 resp fail impaired by?
- diffusion or V/Q mismatch
- most common V/Q mismatch - alveoli collapsed or fluid filled
- O2 supply/demand imbalance = tissue hypoxia = impaired perfusion = develop lactic acidosis and MODS
What do you want for PaO2?
60-65 is aprx = SaO2 90%
what happens when PaO2< 60
chemoreceptors sense and trigers resp center to increase ventilation
early ABG= later= pH 7.33 7.37 PaO2 58 50 PaCO2 30 40 HCO2 24 24
without intervention fatigue sets in
type 2 resp failure impaired by?
- ventilation moving air in and out of lungs
- when lungs cant clear CO2**
what do we see in hypercapnic resp failure?
- PaCO2 changes
Initial ABG: Later: chronic
pH 7.50 7.45 partial or full comp
PaO2 75 75
PaCO2 50 50
HCO3 24 30 compensation
ETCO2 monitor
Continuoue end tidal CO2 monitor
- can have small deviation of 0-5mmHg normal
- ***look at trend
- measure CO2 at end expire
compensatory mechanisms
central chemoreceptors
- medulla (resp center): increased CO2 = increased RR and TV
- periph aortic arch and baroreceptors increased CO2 = increase RR and TV
SNS- responds to hypoxemia to increase HR = increased supply
Vasodilation
diagnose ARF
- clinic presentation
- Hx
- ABG
- CXR/CT
- V/Q scan (PE)
- Cand S samples
- CBC
PT admitted with asthma. sedated on vent ACV: TV 650, RR 10, FiO2 30 %, PEEP 0
Why?
the longer I:E ration decreases air trapping and auto peep improving
classification of pneumonia
1. site of acquisition** CAP -- gram + -- strep/ staph -- < 48 hrs from admission -- thin watery sputum HAP -- gram - -- h. influ, e. coli -- > 48 hrs from admit -- thick yellow sputum
Aspiration Pneumonia
VAP
- 64%
- staph/strep
2. causal agent
3. severity
- staph/strep
ABX start…. then….
start broad spectrum and send cultures
then: narrow by gram stain - or + (24 hrs)
then: narrow culture and sensitivity (48hrs)
promoting gas exchange
diffusion:
- CPAP, EPAP, PEEP
- recruitment maneuvers
- FiO2
- Lasix/minimize IV fluids
- ABX
V/Q mismatch:
- position HOB, good lung down, prone
- suctioning
- PEEP
- optimize CO
- vasopressors, heparin
promoting ventilation
WOB:
- BiPAP, CPAP
- frqnt SBT
- nutrition - resp muscle function
- mobilize
- suction
- bronchodilators/ABX
Volumes and rate:
- increase set TV and RR
- increase pressure support
- sedatives/analgesics
- paralytics
when do you use CPAP
only with O2 issues. same pressure the entire cycle
When to use BiPAP
for vent and gas exchange issues
- senses inspire and delivers high flow air/O2 mix and maintains the whole cycle
IPAP - for vent
- 10-20
- boost of air each breath
- adds TV
- monitor PaCO2
EPAP/FiO2 - for gas exchange
- 5-10
- prevents alveoli from complete empty
- monitor PaO2
- PT needs to be awake and protect own airway
- if not success then mech vent
NIPPV
non-invasive + pressure vent
- CPAP or BIPAP
- uncomfortable = anxiety
- major aspiration risk
- can put air into stomach
- need to be able to remove on own
- NPO
- short term
assess PTs on NIPPV
- WOB, TV, RR, SpO2, ETCO2 , hemodynamics, LOC
- check ABG 30 min after starting or change in settings
- improve should be within 1 hr, if not in 2 may need to be intubated
Hyperglycemia in critical illness
- glucose >10 twice in 24 hrs
- weakens the immune defense system
- contributes to abnormal inflammatory responses to infection
- induces elevated lactate levels
intubation
- compromised airway
- cough,gag, secretions, vomit, GI bleed, upper airway edema, obstruction, decrease LOC, - Severe Oxygenation issue:
- rapid shallow breathing
- tachycardia, diaphoresis
- ABG= hypoxemia, poss resp alkalosis - Severe vent issue
- rapid, shallow breathing or apnea (drug OD)
- tachy, diaphoresis
- HX: COPD, decresed LOC, pneumonia,)
- ABG = resp acidosis - Anticipated clinical course
- PT likely get worse
- PT with little reserve to compensate (loss resp muscles from long admit, chronic ill)
