Critical Care Flashcards
(53 cards)
1
Q
Intubation and Mechanical Ventilation:
Who needs it
A
- Respiratory failure: lose the ability to ventilate adequately
- Hypoxemia
- Hypercarbia
- Inability to protect airway
- Failed non-invasive ventilation (BiPAP or CPAP)
- Procedures requiring general anesthesia
2
Q
Rules for Intubation
A
- Always intubate under direct visualization of the vocal cords
- Always confirm ET tube placement with auscultation of all lung fields
- Follow up with a chest x-ray
- Proper position of ET tube is 3- 5cm above the carina
3
Q
complications of ventilhation
A
- Reduced MAP after intubation and implementing mechanical ventilator support is common due to:
- Reduced venous return from positive pressure ventilation
- Reduced endogenous catecholamine secretion
- Administration of drugs used to facilitate intubation
- Usually volume responsive hypotension
4
Q
What is the preferred method of ventilation for long term vent management
A
Tracheostomy
5
Q
indications for tracheostomy
A
- Long-term or permanent airway obstruction
- Long-term mechanical ventilator
- Unable to clear their airway secretions
- Facilitate liberation from mechanical ventilator
6
Q
benefits of tracheostomy
A
- Improved oral hygiene
- More comfortable
- Need for less sedation
- Can progress to speaking valves and normal eating practices possibly
- Decreases airway resistance and dead space -> lead to faster ventilator wean
- Easy access to airway
7
Q
complications of tracheostomy
A
- Acute
- Hemorrhage
- Mal-positioning
- Pneumothorax/pneumomediastinum
- Neck hematoma
- Long Term
- Tracheoesophageal fistula
- Tracheo-innominate fistula
- Tracheomalacia
- Tracheal stenosis
8
Q
name 4 types of ventilhator modes
A
- Ventilator modes:
- Volume control
- Pressure control
- Pressure support
- Non-invasive ventilation: BiPAP
9
Q
Complications of mechanical ventilhation
A
- Barotrauma – pneumothorax, SQ emphysema, pneumomediastinum, pneumoperitoneium, alveolar rupture
- Lung injury
- Ventilation/perfusion mismatch
- Decreased hemodynamics
- Myopathy
- Ventilator assistant pneumonia
10
Q
•Patients who can be Extubated
A
- Is the patient stable on minimal ventilator settings?
- FiO2 <50% with PaO2 by blood gas>60
- PEEP<10
- PS<7
- Did the patient pass a spontaneous breathing trial (SBT)?
- PSV with PS typically of 7 and PEEP of 5 (some institutions will do PS of 0)
- Rapid-shallow breathing index (RSBI) <100
- Ration of RR to TV
- No evidence of increased work of breathing or hemodynamic instability
11
Q
•Fraction of inspiration oxygen (FiO2)
A
- Definition: fraction of oxygen in the volume being measured
- Room air: 21%
- 1-2L via nasal cannula: 25%
- 10L via nonrebreather: 50%
•Should be on the lowest possible FiO2 necessary to meet oxygenation goals, usually peripheral saturations between 90-96%
•Increased FiO2 can lead to oxygen toxicity, parenchymal injury, hypercapnia, and absorption atelectasis
12
Q
•Positive end expiratory pressure (PEEP)
A
- Definition: pressure added at the end of expiration that prevents alveolar collapse
- Usual initial dose if 5 cm H20 but can increase up to 20 cm H20
- Recruits alveoli that have collapsed, which increases the surface area for gas exchange
- ARDS patients are typically treated with low TV and high PEEP
- Increased PEEP can lead to decreased cardiac function, barotrauma, and impaired cerebral venous outflow
13
Q
•Tidal Volume (TV)
A
- Definition: the amount of air delivered with each breath
- Ideal TV is 6-8 mL/kg of IBW à use IDEAL weight
- Patients with ARDS should have low TV of <6 mL/kg of IBW
14
Q
•Pressure Support (PS)
A
- Definition: a set pressure that is delivered during inspiration (driving pressure)
- Can be set anywhere from 0-30 mmH20, normal is usually 7-10 mmH20
- The higher the PS, the larger the patient’s TV will be
15
Q
Volume Control
A
- These are good “set it and forget it” modes
- Less useful for awake patients
- Can be very uncomfortable for patients
Synchronized intermittent mandatory ventilation
- A good starter weaning mode that allows patients to take independent breaths between set breaths.
- Patient triggered breaths will not receive the set TV, but will receive the set PS
- Better preservation of respiratory muscle function
- If patient is tachypneic there is a high likelihood of vent dyssynchrony
Assist Control
- A good mode for patients that are sedated or newly intubated
- Clinicians set the minimal minute ventilation by setting the RR and TV
- Patient triggered breaths will receive the set TV
- If patient is tachypneic there is a high likelihood of Auto-PEEP (incomplete expiration prior to the initiation of the next breath leads to air trapping)
16
Q
Pressure Control
A
Each breath is given a set amount of pressure via the ventilation
- The clinician is setting the inspiratory pressure and inspiratory time
- The resulting TV depends on the set driving pressure, TV will be varied
- Advantages: Can have strict control over the airway pressure which can help with barotrauma and fresh suture lines
Disadvantages
- Can not wean from this mode
- Can be very uncomfortable
17
Q
Pressure Support
A
Only set the pressure support and PEEP
- The patient’s TV and RR are not set, rather the patient receives assistance with each breath
- Patient needs to initiate the breath
- The preset variable is the set amount of PS and PEEP
- Ideal for weaning
- More comfortable mode
Patient’s need close monitoring due to no set TV and minute ventilation and can lead to hypoventilation
18
Q
Non-invasive ventilation: BiPAP
A
Used for non-intubated patients
- Used for patients with impending respiratory failure or who is struggling after extubation
- BiPAP provides assistance with the mechanics of ventilating (regulating oxygen and carbon dioxide)
- Can adjust the inspiratory and expiratory pressures to achieve a desired TV
Advantages:
- Can prevent intubation
- Intermittent use
Disadvantages:
- Claustrophobic, patients tend not to tolerate it
- Patient’s can not eat or drink while mask is on
- Can dry up secretions and cause a mucus plug
19
Q
define Acute Respiratory Distress Syndrome (ARDS)
A
- Acute, diffuse, inflammation form of lung injury that is associated with a variety of etiologies
- High mortality rate: ~30%
20
Q
criteria for dx of ARDS
A
- Bilateral infiltrates on chest x-ray
- Progressive respiratory failure
- Hypoxemia that does not respond to increase FiO2
21
Q
most likely causes of ARDS
A
- Sepsis
- Pneumonia
- Trauma
- Multiple transfusions
- Aspiration of gastric contents
22
Q
3 phases of ARDS
A
- Exudative
- Alveolar edema occurs in dependent regions from injury to the alveolar barrier
- High concentrations of inflammatory cytokines -> recruitment of leukocytes
- Usually occurs within 7 days of chest x-ray findings
- Proliferative
- Usually the next 7-21 days, associated with recovery
- can wean to extubation during this time, but still may have symptoms
- Fibrotic changes can happen late in this phase -> poor recovery predictor
- Fibrotic
- Not all patients move to this phase
- Develop interstitial fibrosis with emphysematous changes
- Increased risk of mortality
23
Q
tx ARDS
A
- ARDS is a syndrome not a disease process -> TREAT UNDERLYING DISEASE
- Ventilator support!!!!
- Use the lowest possible settings for PEEP, TV, and FiO2 to achieve a PaO2 via arterial blood gas of 55 mmHg
- Protect lungs from barotrauma with low tidal volumes - Target <6 mL/kg of IBW
- Goal pH via arterial blood gas >7.3
- Avoid aggressive fluid resuscitation if possible, can cause worsening pulmonary edema
- Goal CVP < 4 and PCWP <8
- Balance between diuresis and end organ perfusion
- Prophylaxis against VTE and gastritis
- Avoid unnecessary procedures
- Aggressive treatment for suspected infections
24
Q
why are low tida volums important in ARDS pts
A
- A large multicenter trial of ARDS patient found that TV of 6mL/kg with plateau pressures <30 cm H2O had significant improvement in mortality over TV of 12 mL/kg
- Over-ventilation caused more alveolar damage which worsened inflammation
- target a goal TV of 6-8 mL/kg
- always look out of elevated plateau pressures
25
indications for arterial lines
* Unstable patients who require vasopressor support
* Severely hypertensive patients requiring IV antihypertensive
* Strick blood pressure control for neuro patients
26
complicatios of arterial lines
* Arterial occlusion can cause limb ischemia
* Limit mobility
* Line infection -\> rare for arterial lines to cause infection but is a possibility
27
possible sites of arterial lines
Brachial
Radial
Femoral
Axillary
28
what is the most central arterial lines / most accurate
femoral
## Footnote
Risk of vascular injury or retroperitoneal bleed à Higher risk of infection
29
which arterial line is most difficult to place but carries less risk of complete occlusion
Axillary
## Footnote
Durable, long lasting and rarely positional
Increased risk of vascular injury
Harder to compress, higher likelihood of hematoma
30
compare and contrast brachial bvs radial arterial lines
_Brachial_
Most comfortable for the patient usually
Larger artery then radial leads to less positional issues
If thrombus forms, risk of compromising whole arm
_Radial_
Least invasive
Smallest artery used, tends to be most positional/unreliable
Usually annoying to the patient
31
indications for Central Venous Lines
* More “long term” access (7-14 days verse 3 days for peripheral IV)
* Administration of certain medication
* Dialysis access
* Close monitoring of central pressures
* Frequent and recurrent lab draws
32
CVP Measurement & normal range
* Can obtain a central venous pressure (CVP) off a central line placed in the IJ or SC vein.
* Normal range is 0-8 mmHg
* This measurement is used in conjunction with other factors to determine fluid status
* Measurement should be made while patient is supine
* Normal respiratory variation is seen
33
complications of central venous lines
* Venous air embolism – keep patient in Trendelenburg position during placement
* Pneumothorax
* Catheter tip malposition – always check x-ray prior to use for IJ and SC lines
* Thrombotic occlusion
* Venous thrombosis – femoral line with highest risk
* Infection – line should ideally be changed every 7-14 days
34
what line are we highly cooncerned for infection and how do we monitor this ?
what are the common pathogens that cause infection?
* Most common pathogen is coag-negative staphylococci, Staph Aureus, gramnegative Bacilli
* should have a high suspicion for any patient with a central line that has been in for over 48 hours who has a new leukocytosis and fever
* Obtain blood cultures
* Remove line and replace in a new location if possible
* Start empiric antibiotics
35
central venous lines can be placed in..?
Internal Jugular
Femoral
Subclavian
36
* The “ideal vein” -\> Least risk of infection
* Most difficult to place
Subclavian
## Footnote
* Increased risk of pneumothorax & hematoma
* Most comfortable
* Unable to use ultrasound
37
•Best venous site for emergency access
Femoral
## Footnote
* Easily accessible -\> US guided below inguinal ligament – otherwise high risk for RP bleed
* Risk for vascular injury -\> Increased risk of bleeding
* Limited mobility
* Increase risk of infection
38
best venous site for for Swans and pacing wires
Internal Jugular
* Easily accessible using ultrasound
* Provides a “straight shot” to the right atrium
* Uncomfortable for patients
39
what is a Swan-Ganz Catheters
•A specialized catheter that gives continuous measurements of right heart filling pressures and indirect left heart filling pressures
40
Swan-Ganz Catheters measure
**•Central venous pressure (CVP**) - which is equal to the RA pressure (Normal \< 8 mmHg)
**•Right ventricular pressure (RV)** -Normal (systolic/diastolic) 15-30/0-8 mmHg
**•Pulmonary artery pressure (PAP)** - Normal (systolic/diastolic) 15-30/4-12 mmHg
**•Pulmonary capillary wedge pressure (PCWP)-** •this is obtained when the balloon is inflated and gives you an estimated of the left side heart pressure (most inaccurate measurement of swan-Ganz catheters) •Normal \<12 mmHg
•Can measure cardiac output and mixed venous oxygen saturation
**•Cardiac output (CO)** - done with thermo-dilution, normal 3-7 L/minute
**•Cardiac index (CI)-** •relates cardiac output from the LV to body surface area, normal \>2.2 L/min
**•Mixed venous oxygen saturation (SVO2)** - the percentage of oxygen bound to hemoglobin in blood returned to the PA (Normal \>60%)
41
complications of Swan-Ganz Catheters
* Mal-positioning
* Myocardial or pulmonary injury – always advance Swan-Ganz catheter with the balloon inflated
* Cardiac valve injury – always pull back the Swan-Ganz catheter with the balloon deflated
* Cardiac arrhythmias – if tip is in the RV can irritate myocardium and cause SVT, VT, Afib, ect
* Infection – similar to central line
* Pulmonary artery rupture – rare but deadly complication caused by overwedging Swan-Ganz catheter and rupturing the PA
42
ICU Medications
Vasopressors - Keep blood pressure up
Inotropes- augment CO/CI
Anti-HTN- keep blood pressure down
43
vasopressors include
Norepinephrine (levophed) - may cause arrhythmias or peripheral ischemia in higher doses
Phenylephrine (Neo-Synephrine) - bradycardia
Vasopressin (Pitressin) - may cause coronary constriction
44
Inotropes include
Dobutamine (Dobutrex) - may cause arrhythmias, worsening HCM
Epinephrine - Lactic acidosis
Milrinone - Hypotension, Arrhythmias, Headache renal function
Dopamine - may cause arrhythmias
45
Anti-HTN include
Esmolol (Brevibloc) - slows AV conduction -\> bradycardia or heart block
Nicardipine (Cardene) - critical aortic stenosis
Nitroglycerin (Tridil) - Headache, increases ICP
Nitroprusside (Nipride) - cyanide accumulation, Kidney, liver
46
when is the only time we do not food pts in ICU
Only time we do not feed if in patient is in shock-\> risk of bowel ischemi
47
when shoudl we start a feeding tube
* When there is inadequate nutrition for 3 days or there is a high risk of aspiration
* Do not start enteric feeds for patients in shock -\> risk of ischemic bowel
48
complications of tube feeds
* Aspiration –can be reduced by having head of bed 30° or higher
* Diarrhea – very common with tube feeds, can change formula or add fiber
* Skin or mucosal damage
49
•Total Peripheral Nutrition (TPN)
* Indicated when enteral nitration is not possible
* Usually wait 5-7 days without nutrition prior to starting
* High complication risk – infection risk
* Needs central line, with a dedicated port
* Dose not prevent intestinal atrophy
50
before using NG tube what must you always do
confrim w/ CXR that the tube is in the correct place
51
•Ideal vent mode for for weaning
Pressure Support
* The patient’s TV and RR are not set, rather the patient receives assistance with each breath
* Patient needs to initiate the breath
52
•Used for patients with impending respiratory failure or who is struggling after extubation
Non-invasive ventilation: BiPAP
* BiPAP provides assistance with the mechanics of ventilating (regulating oxygen and carbon dioxide)
* Can adjust the inspiratory and expiratory pressures to achieve a desired TV
Advantages:
* Can prevent intubation
* Intermittent use
Disadvantages:
* Claustrophobic, patients tend not to tolerate it
* Patient’s can not eat or drink while mask is on
* Can dry up secretions and cause a mucus plug
53
* The clinician is setting the inspiratory pressure and inspiratory time
* The resulting TV depends on the set driving pressure, TV will be varied
Pressure Control
Each breath is given a set amount of pressure via the ventilation
•_Advantages_: Can have strict control over the airway pressure which can help with barotrauma and fresh suture lines
_Disadvantages_
* Can not wean from this mode
* Can be very uncomfortable
