Evidence Based Infections in Ventilated Patients Flashcards
Do patients often aspirate when they are ventilated? What are some factors to decrease aspiration?
yes. esp if they have eaten within the last 6 hours.
factors to decrease aspiration:
rapid sequence intubation
holding cricoid pressure
What is so bad about stomach contents getting into the lungs?
There is…
ACID–>can cause chemical pneumonitis
BACTERIA-gram neg., can get infection
both damage respiratory endothelial cells
How do the oral secretions of hospitalized patients change?
they become more negative.
the receptors on epithelial cells of mouth bind pathogenic organisms…
Where is the pool of death located? What does that mean?
located behind the balloon of the endotracheal tube
this is filled with oral secretions that can get in to the lung & wreck havoc
What can you do to help this aspiration problem?
- decontaminate the oral cavity
2. subglottic suctioning-decreases puddle of death
What is involved in decontaminating the oral cavity?
chlorhexidine antiseptic for mouth–decreases gram + organisms
H2 blockers to decrease acid secretions.
**decreases pneumonia 31-10% & bacteremia decreased by 1.9%
What is the most common nosocomial infection?
ventilator associated pneumonia, 65%
>90% occur with mechanical ventilation
What is the usual microbiology of hospital acquired pneumonia?
mostly gram neg naerobic bacilli (75%)-ex: pseudomonas
some gram +
What is the usual microbiology of community acquired pneumonia?
Pneumococci
Atypical organisms
Viruses
T/F Many of the gram neg. bacteria in VAP are multi drug resistant.
True.
What are 2 things that antibiotics must cover for hospital acquired pneumonia, specifically VAP?
gram neg. bacilli & MRSA/Staph Aureus
What is involved in the diagnosis of pneumonia?
Fever or hypothermia
Leukocytoses or leukopenia
Increased respiratory secretions
New or worsened infiltrate on chest x-ray
In patients on ventilators there a bunch of causes of pulmonary infiltrates. What are some of them? What % of them are included under the category of pneumonia?
1/3 pneumonia
Atelectesis-someone not breathing deeply enough, alveoli don’t open up=opacity
Effusions
Pulmonary edema looks similar to pneumonia
Pulmonary contusion (trauma). Bruises on lungs can look like pneumonia.
ARDS
What are you looking for when you test tracheal aspirate?
WBCs-infection
macrophages-infection
more than 10 squamous cells–>indicates more oral than tracheal aspirate
What is the accuracy of tracheal aspirate in diagnosing VAP?
sensitive but not specific
sens: if neg. no VAP
not specific–>if pos. could just be normal colonization of sputum in intubated patients
What is involved in bronchoalveolar lavage?
can test for pathogen & is therapeutic
Bronchoscopy and occlude the distal airway that appears to have pneumonia
Instill sterile saline
Suction fluid and send for quantitative culture (104)
How is acute respiratory distress syndrome diagnosed?
- bilateral infiltrates on CXR
- wedge<18; no clinical signs of LA HTN
- hypoxemia even with high PEEP
WHat is the PO2/FIO2 ratio of normal people? For a definition of ARDS, what must your PO2/FIO2 be? How about for ARDS diagnosis after acute lung injury?
Normal; PO2/FiO2=500
ARDS diagnosis: <300
What are the 2 types of ARDS?
- primary–injury of lung thru trauma or pneumonia etc.
- systemic-associated with a system wide deal
* *systemic activation of inflammation–CRP would be present
What are some systemic conditions associated with ARDS?
- Shock
- Trauma
- Sepsis/Infection (even nonpulmonary)
- Transfusion
- Inhalation of Toxic Gases: smoke, meth
- Aspiration of Gastric Contents (esp if there are drugs there or it is super acidic)
- Intra-abdominal catastrophe-infarcted bowel or pancreatitis)
- multiorgan failure
What are the stages of ARDS?
- Prodrome-feel sick
- Acute or Exudative Phase
- Proliferative Phase
- Fibrosing Alveolitis (10+ days)
- Recovery
What period of time makes up the prodrome? What are the symptoms at this time?
12-36 hrs
dyspnea, tachypnea, resp alkalosis (low pCO2 w/ normal pO2)
agitation
What does the CXR show in the prodrome phase of ARDS? What is happening physiologically at this time?
CXR: mild increase in pulmonary vasculature
Physiologic: inflammatory mediators present, platelet aggregates, fibrin plugs
What period of time makes up the acute or exudative phase? What is the main symptom in this phase?
up to 7 days
Hallmark: HYPOXEMIA
What is shown on CXR & what is happening physiologically @ acute/exudative phase of ARDS?
CXR: bilateral infiltrates-can look like cardiac edema
Physio: capillary endothelial damage–>alveolar edema
neutrophil activation
alveolar epithelial disruption: lots of protein, blood, hyaline, water w/ exudates
What’s going on @ the histo level during the acute/exudative phase of ARDS?
Type 1 Alveolar Cells–>denuded & contributing to pulmonary edema, allows bacteria into bloodstream
Type 2 Alveolar Cells–>surfactant loss–>atelectesis
What is an important thing to give to babies who are born prematurely?
artificial surfactant
What happens to the inflammatory system during the acute/exudative phase of ARDS?
Activation of Inflammatory System:
Macrophage Inhibitory Factor (Anterior Pituitary)
Pro-inflammatory: Increases IL-8 and a-TNF.
What is the timeframe for the proliferative phase of ARDS? What’s the hallmark of this period? What else is going on?
7-10+ times Hallmark: hypercarbia increased alveolar thickness, increased shunt collagen is laid down, less exudate alveolar fibrosis begins
What’s the deal with the hypercarbia in the proliferative phase of ARDS?
CO2 always exchanges better than O2. At this stage of collagen proliferation etc. even CO2 can’t be exchanged.
WHat is the timeframe for the fibrosing alveolitis stage of ARDS?
10+ days
increased alveolar thickness
once again, hypercarbia
**thickening & narrowing of vessels
What are some possible complications of the fibrosing alevolitis stage of ARDS?
some develop a pneumothorax
pulmonary HTN
right heart failure
increased mortality
What happens during the recovery phase of ARDS?
macrophages go to work in protein removal
neutrophil apoptosis
type II cells can differentiate into type 1
**Gradual improvement in hypercarbia & hypoxemia
How long does it take for patients to return to normal after ARDS?
6-12 months
What is a treatment during sepsis in patients with ARDS?
vasopressors-increase CO
fluid resuscitation–sometimes blood products w/ increased Hb for oxygen carry capacity
T/F It is best to use osmotic fluids, such as dextrose or albumin, in patients with lung damage, compared to regular IV fluids.
False. Sometimes it can do damage. So use regular IV fluids.
Conservative fluid groups in research have fewer ICU days.
After you send cultures for a patient with sepsis, what do you do next?
STart them on super broad spectrum antibiotics. Then after you get the culture results you can narrow it down.
Which antibiotics can address resistant gram +?
vancomycin
linezolid
Which antibiotics address gram - & anaerobes?
cefipime (a 4th gen cephalosporin)
merepenem
Which drugs can address fungal infections?
fluconazole, caspofungin
T/F Early enteral feeding may reduce sepsis in critically ill patients. ALso, arginine may help.
True.
What is PEEP? What is this value in a healthy person?
positive end expiratory pressure
glottis closes–>PEEP
Healthy person: 5 PEEP, low value
higher PEEP, allows us to keep alveoli open all the time b/c if it is opening & closing can cause shearing in an unhealthy person
What does an increased PEEP do to FiO2? What is a goal FiO2 for a sick person?
increased PEEP=decreased FiO2
you want FiO2<60% to reduce O2 toxicity
What type of tidal volume do you want to use for lung protective ventilatoin?
low tidal volumes (6cc/kg)
decreases the inflammatory response
protect the fragile lungs b/c our alveoli are open the whole time
T/F Permissive hypercapnia is harmful.
False. low pH can be controlled by dialysis.
What are other forms of ventilator support?
high frequency jet ventilation
high frequency oscillator ventilation
airway pressure release ventilation (pretty effective)
Which position is most therapeutic for ill patients w/ lung issues? WHy?
prone position-on stomach is best
when supine: posterior alveoli collapse & get V/Q mismatch w/ too much perfusion to these posterior alveoli
What is an alternative to prone positioning?
rotational therapy–rotate patient 270 degrees to improve oxygenation
**Can do with 4 people or super fancy machine
