Critical Care Flashcards
ID a patient who is in need of mechanical ventilation
- (2 parts)
- Respiratory Failure: cannot ventilate adequately on own (Hypoxia, Hypercarbia)
- Inability to protect airway
- Failed non-invasive ventilation (BiPAP or CPAP)
- Procedures requiring general anesthesia (breathing is paralyzed)
[Pulmonary Disease]
- ARDS, pulmonary edema, hypoventilation, failed trail of extubation, forseeable protracted course of respiratory failure, infection, ventilatory failure (lactic acidosis, dec lung compliance)
[Circulatory]
- Cardiopulmonary arrest
- Shock
[Airway Support]
- Diminished mental status, compromised airway anatomy, diminished airway reflexes, fluctuating consciousness, sedation, pharyngeal instability
[Other]
- ELEV Intracranial Pressure, requiring hyperventilation
Recall complications of endotracheal intubation
***Reduced MAP (mean arterial pressure: avg of arterial pressure t/o 1 cardiac cycle) is common b/c
- RED Venous return from positive pressure ventilation
- RED Endogenous catecholamine secretion
- Admin of drugs used to facilitate intubation
^Leading to volume responsive hypotension
[Common]
1. RT main stem intubation
2. Esophageal intubation
3. Gastric aspiration > PNA
4. Dental trauma
5. ET tube migration
6. Laryngeal damage
——–
[Others]
- Arrhythmias, hemodynamic instability, mucosal lac/tear/ulceration, otitis, sinusitis, tracheoesophageal fistula, vocal cord paralysis, tracheomalacia (collapse), tracheal stenosis (narrowed)
Tenets of intubation
- Always intubate under direct visualization of the vocal cords
- Always confirm ET tube placement with auscultation of all lung fields
- F/U CXR
- Proper position of ET tube is 3-5cm above Carina
ID a patient who is a candidate for Tracheostomy
- Preferred method for long-term ventilation
- Long-term or permanent airway obstruction
- Long-term mechanical ventilator
- Unable to clear their airway secretions
- Facilitate liberation from mechanical ventilator
Explain common complications of Tracheostomy
[Acute] 1. Hemorrhage 2. Mal-positioning 3. Pneumothorax/pneumomediastinum 4. Neck hematoma [Long Term Complications] 1. Tracheoesophageal fistula 2. Tracheo-innominate fistula 3. Tracheomalacia 4. Tracheal stenosis
Fraction of inspired oxygen (FiO2)
- Fraction of oxygen in the volume being measured
- should be lowest possible FiO2 possible to meet oxygenation goals – usu 90-96% SAT
- INC FiO2 can lead to O2 toxicity, parynchemal injury, hypercapnia, + absorption atelectasis
Positive End Expiratory Pressure (PEEP)
- Pressure added at the end of expiration that prevents alveolar collapse
- initial dose 5 cm - 20cm, recruits alveoli that have collapsed > INC SA
- ARDS = TX with low TV, high PEEP
- INC PEEP > DEC cardiac function, barotrauma, + impaired cerebral venous outflow
Tidal Volume
- The amount of air delivered with each breath
- Ideal = 6-8 mL/kg of IBW
- ARDS; low TV, <6
Pressure Support - Definition
- A set pressure that is delivered during inspiration (driving pressure)
- 0-30 mmH20; Norm 7-10
- Higher the PS, larger the TV
Volume Control
*PT receives a set volume of air, a set # of times, per min set it and forget it modes
less useful for awake pts, uncomfortable
- Synchronized Intermittent Mandatory Ventilation (SIMV)
- Allows for patient to take independent breath b/t sets; better preservation of respiratory muscle fxn
- PT triggered breaths: wont get set TV, will get set pressure support
- Tachypneic PT has high likelihood of vent dysynchrony - Assist Control (AC)
- Newly intubated or sedated pts, clinicians set the minimal ventilation via RR + TV
- PT triggered breaths will get TV, do not use their own muscles
- Tachypneic PT has high likeihood of Auto-PEEP (or incomplete expiration b/f the initiation of next breath > air trapping)
Pressure Control - PC
*Each breath is given a set amt of pressure via Ventilator clinician sets the Inspiratory Pressure + Time
resulting TV depends on set driving pressure > TV will be varied
(+) Can have strict control over airway pressure, can help w/ barotrauma + fresh suture lines
(-) can not wean from this mode, can be very comfortable
Pressure Support - PS; ventilator mode
- Only set the pressure support + PEEP
- TV and RR are not set; pt receives assistance with each breath - pt needs to initiate breath
- ideal for weaning, comfortable
- pt needs close monitoring due to no set TV & minute ventilation > hypoventilation
Non-Invasive Ventilation (BiPAP)
*Non-intubated patients, impending respiratory failure or who are struggling after extubation
- provides assistance with mechanics of ventilating (O2 + CO2 regulation), can adjust inspiratory + expiratory pressures > achieve desired TV
(+) can prevent intubation, intermittent use
(-) claustrophobia, can’t tolerate it, cannot eat or drink, can dry up secretions + cx mucus plugs
Mechanical Ventilation Complications
- Barotrauma (PNEUMOTHORAX, SQ emphysema, p-mediastinum, p-peritoneium, alveolar rupture)
- Lung injury
- Ventilation/Perfusion mismatch
- DEC Hemodynamics
- Myopathy - (dysfxn of diphag)
- Ventilator-Assisted PNA
ID a patient who is ready to be extubated
- Underlying cx reversed or improved?
- Hemodynamically stable?
- Awake, alert, + following commands?
- Protect airway? Strong enough to manage secretions?
- Stable on minimal ventilator settings?
FiO2 <50%, PaO2 by blood gas >60PEEP <10, PS <7 - pass the Spontaneous Breathing trial (SBT)?
PSV w/ PS 7, PEEP 5Rapid-shallow breathing index (RSBI) —ratio of RR to TV; <100
`no evidence of INC work or hemodynamic instability
Acute Respiratory Distress Syndrome - DEF, CXR findings
*acute, diffuse, inflammation form of lung injury that is assoc with variety of etios
DX —
1. Bilateral infiltrates on CXR
2. Progressive respiratory failure
3. Hypoxemia that does not respond to INC FiO2
Etios —
- Sepsis, PNA, Trauma, Multiple transfusions, Aspiration of gastric contents
~ 30% Mortality
ARDS — (3) Phases
- Exudative -
alveolar edema from injury to alveolar barrier > high cxns of inflammatory cytokines > recruitment of leukocytesoccurs w/i 7 Ds of CXR - Proliferative -
next 7-21 Ds, assoc with recovercan wean to extubation, but may still have sx
`fibrotic chngs can occur, poor outcome predictor - Fibrotic -
Not all patients get here - INC mortality riskDvlp Interstitial Fibrosis with Emphysematous changes
ARDS — TX
Syndrome, TX underlying DZ process!!!
- Ventilator Support:
**LOW TIDAL VOLUMES IN ARDSlowest possible settings for PEEP, TB, and FiO2, achieve PaO2 via ABG og 55mmHg + pH of >7.3
protect lungs from barotrauma w/ low TV’s; <6 - (6-8 is goal)
- Avoid aggressive fluids; CVP <4, PCWP <8
- Avoid unnecessary procedures
- Aggressive TX for suspected infxns
- Prophylaxis agnst VTE + gastritis
Radial Arterial Line
(+) Least invasive
(-) smallest artery, tends to be most positional/unreliable, usu annoying to PT
Brachial Arterial Line
(+) Most comfortable for pt, larger than radial > less positional issues
(-)**Thrombus puts entire arm @ risk for compromised BS!!
Axillary Arterial Line
(+) Durable, long-lasting, reliable, sturdy + rarely positional, larger than radial w/ less risk of complete occlusion
(-) Most difficult to place, INC risk of vascular injury, harder to compress, HIGH risk of Hematoma
Femoral Arterial Line
(+) Most central arterial line - most accurate, easy + quick access, if patient is coding - USE this!
(-) Risk of vascular injury, retroperitoneal bleed, higher risk of infxn (dirty area)
Arterial Lines
*Catheter placed directly into the artery, allows for continous real-time BP monitoring
INDIC FORUnstable PTS who require Vasopressor support
Severely HTTN pts requiring IV antiHTTN
`Strict BP control for neuro pts
(-) prone to error from pt position, vasospasm, or cath occlusion
*Use bad waveforms to indicate under/over TX
Overdamped - falsely low, moving/clot
Underdamped - falsely high, extrafling
Explain the most common complications from arterial lines
1. Arterial occlusion – can cause limb ischemia
- Limited mobility
- Line infxn – rare, but possible
Internal Jugular Central Line
(+) Easily accessible via US, provides a “straight shot” to the RT atrium, ideal for Swans + pacing wires
`close proximity to carotid artery - relatively superficial, easy to US
(-) Uncomfortable for PTS - larger line, hangs off neck
Subclavian Central Line
(+) The “ideal vein”, least risk of infxn, most comfortable
(-) **INC risk of PneumoT, most difficult to place, INC risk of hematoma, unable to use US
`performed w/ anatomy landmarks b/c US difficult from bone interference - insert needle @ 15 angle w. needle pointing at sternal notch > advance needle till you hit clavicle > press down under
Femoral Central Line
(+) Easily accessible, best sites for ER accessgold standard is US guided
Iinsertion site BELOW inguinal ligament
(-) Risk of vascular injury, INC risk of bleeding, limited mobility, INC risk of infxn (dirty area)
`xray not useful
Central Venous Lines
*large catheter placed directly into a centrally located vein
INDIC
- Long-term access (7-14 D, v.s 3 for IV v.s wks/mths PICC line)
- ADMIN of certain meds
- Dialysis access
- Close monitoring of central pressures
- Freq/recurrent lab draws
*Locate anatomy, sterile procedure, confirm placement via US, then confirm via xray
Central Venous Lines - Complications
- Venous air embolism - (keep pt in Trendelenburg position during placement)
- PneumoT
- Catheter tip malposition - (always check xray b/f use for IJ + SC lines)
- Thrombotic occlusion
- Venous thrombosis - (fem line w/ HIGH risk)
- INFXN – (should be chnged 7-14 Ds)
MC pathogen = coag-neg Staphylococci, Staph Aureus, GN Bacillishould have HIS for any pt w. a central line in >48 hrs with new leukocytosis + fever - Blood CX
- Remove line, replace in new location
- Empiric anbx - narrow w/ culture, 10-14 D course
Describe the use of Swan-Ganz catheters
*specialized cath that gives cont. measurements of RT heart filling pressures + indirect LT heart filling pressures
- CVP, RV, PAP, PCWP
can also assess…
- CO, Cardiac Index (CI), mixed venous O2 SAT
Central Venous Pressure - (CVP)
*reflects central venous pressure; equal to the RA pressure
Norm = <8 mmHg
Pulmonary Artery Pressure - (PAP)
*measures the cont pressure in the Pulmonary Artery
Norm: Sys = 15-30/Dia = 0-8 mmHg
Pulmonary Capillary Wedge Pressure - (PCWP)
*obtained with balloon inflation - estimated LT side of heart pressure (least accurate)
Norm = <12 mmHg
Recall the complications of Swan-Ganz catheters
1. Mal-positioning
- Myocardial or pulmonary injury - (always advance cath with balloon inflated)
- Cardiac valve injury - (always pull back with balloon deflated)
- Cardiac AA’s - (tip can irritate RV - SVT, VT, afib)
- Infection - (sim to central line)
- ***Pulmonary Artery rupture - (rare, but DEADLY complication caused by over-wedging cath - in too far, inflating)
ID a patient who would benefit from vasopressor support
*PT whose blood pressure keeps dropping
1. Norepinephrine -
caution = AAs, peripheral ischemia in higher doses
2. Phenylephrine -
caution = bradyc
3. Vasopressin
caution = coronary constriction
Recall the importance of inotopic support:
*IF pt needs augmented CO/CI - INC contractility of heart; (+) inotropes
1. Dobutamine
caution = AAs, worsening HCM
2. Epinephrine
caution = lactic acidosis @ high doses
3. Milirinone
caution = hypoT, AAs, HA, renal fxn
4. Dopamine
caution = AAs
Summarize the importance of anti-hypertensives
*IF need to keep blood pressure down
1. Esmolol
caution = slows AV conduct, bradyc, heart block
2. Nicardipine
caution = critical aortic stenosis
3. Nitroglycerin
c = HA, INC ICP
4. Nitroprusside
c = cyanide accumulation, kidney, liver
Recall when an ICU patient should be initiated on tube feeds
*Feeding gut prevents atrophy of barrier against infection. Poor nutrition > longer ICU stay + healing
Start If…
*inadequate nutrition for 3 D or if HIGH risk of infxn
Standard NG - directly into stomach
Dobhoff tube - smaller, usually post-pyloric
Explain whether to use tube feeding or TPN for nutrition
TPN:
- indicated when enteral nutrition is not possible - wait 5-7 D w/o nutrition b/f start
- high complication + infxn risk; does not prevent intestinal atrophy
