ICU Flashcards
Types of Shock
- Sepsis - loss vascular tone
- Hypovolemic - loss preload
- Obstructive - inc after load (PE, tamponade, constrictive pericarditis)
- Cardiogenic - pump failure (ACS, valvular)
- Anaphylactic/distributive - SIRS, endocrine, mitochondrial dysfunction
Central venous O2 sat
- Get from CVC (SVC), normal 60-65%
- Mixed central is from pulmonary artery catheter (SVC and IVC), normal 65-70%
ScvO2 >80% = sepsis
- Cells of body are too sick to extract O2 from blood and blood is in high flow state
ScvO2 <60% = cardiogenic
- Heart can’t pump blood with O2 to cells
Sepsis and Septic Shock definitions
- Sepsis - life threatening organ dysfunction by dysregulated host response to infection. Mortality >10%
- qSOFA score - Septic shock - subset of sepsis with profound circulatory, cellular, metabolic abnormalities. Mortality >40%
- Lactate >2
- Need pressers for MAP >65 in absence of hypovolemia
qSOFA score
2/3 of: 1. RR>22 2. SBP <=100 3. Altered LOC (GCS<15) If positive = think infection
Surviving Sepsis Categories
- Initial resuscitation
- Abx - empiric broad spectrum
- Fluid - crystalloid>colloid, 30 mL/kg bolus
- Vasopressors - NE > vaso, epi
- Steroids - if refractory septic
- Blood - RBC if Hb <70, plt <10 or <50 and bleeding
- Mech vent - lung protective ventilation
- Adjunctive
- Bicarb - only pH <7.15
- Nutrition
- DVTp
Sepsis 1st hour
- Lactate - repeat q2-4 if >2
- Cultures
- Broad spec ABx
- IVF - 30 mL/kg for HOTN or lactate >4
- Pressors if HOTN for MAP 65+
Which fluid for sepsis?
Crystalloid (RL) unless CI
- HyperK
- Mitochondrial disease
- TBI
- Can use albumin in addition if significant amount of crystalloid given
- No bicarb if pH >7.15
How much fluids in sepsis?
- 30 mL/kg in first 4 hours
- Then use dynamic measures to determine ongoing needs:
- NOT CVP
- Passive leg raise
- Fluid challenge - inc SV/CO by 10-15% after 250-500 cc
- Pulse pressure variation
- Stroke volume variation
- IVC variation distensibility index - int/vent >15-20% likely, not int >40% likely, low doesn’t mean non responder
Why do you need to know if your patient is fluid responsive?
- If you have maximized their preload then giving more fluid won’t help their blood pressure/perfusion
- If you give more fluid than they need you risk ARDS, AKI, intra abdominal compartment syndrome
Vasopressors
- NE - alpha effect, 0.03-0.35, can add vast or eps
- Vasopressin - 0.03 u/min
- Epi - increases lactate (can’t use to guide)
Adrenergic receptors
Alpha 1 = inc SVR
Alpha 2 = dec SVR (clonidine)
Beta 1 = inc chronotropy (rate), inotropy (contractility), domotropy (conduction)
Beta 2 = relax smooth muscle/GB/uterus, bronchodilator
Phenylephrine
Alpha 1
- Reflex bradycardia
- Use in opioid induced HOTN
- Dec HR and CO, inc SVR and PCWP
Norepinephrine
Alpha 1, a bit of beta 1
- 0.03 - 0.3 mcg/kg/min
- Inc HR, CO, SVR and PCWP
Dopamine
High dose - alpha 1
Low dose - beta 1/2
High risk tachy vs. NE
- Inc HR, CO, SVR, PCWP
Epinephrine
High dose - alpha 1
Low dose - beta 1/2
High risk of tachy vs. NE
- Inc HR, CO, SVR, dec PCWP
Dobutamine and isoproterenol
Beta 1 and Beta 2
- Inc HR/CO, dec SVR/PCWP
Milrinone
Beta 1 and Beta 2
- NOT in renal failure
- Very long half life
- Inc HR/CO, dec SVR/PCWP
Vasopressin
Works on its own V1 receptor causing vasoconstriction = inc SVR
Can cause digit and gut ischemia
- Inc SVR/PCWP
Steroids in Sepsis
Only if REFRACTORY septic shock- not responding to IVF and pressors
Hydrocortisone 200 mg/day total
- 100 mg loading dose
- 50 mg QID x5-7 d
Hypoxemic Respiratory Failure - Type 1
- PaO2 <60
- V/Q mismatch
- Low FiO2, diffusion, alveolar, shunt
Hypercapneic respiratory failure - type 2
- PaCO2 >45
- Can be accompanied by hypoxemia
Post operative respiratory failure
- Atelectasis, low FRC
- Secondary chest wall/anesthetic
Circulatory collapse respiratory failure
- Shock
- Severe acidosis
HFNC
- Humidified O2, up to 60 L/min
- AGMP - PPE***
- May help reduce rates of intubation
Benefits - Dec constriction, inc secretion clearance
- Dec dead space
- Dec upper airway resistance
- Recruit atelectasis
- Inc FiO2
When to use NIPPV
Definitely
- Mild-sev acidemia COPD (CO2>45, pH<7.35, RR>20-40)
- Cardiogenic pulmonary edema (excl MI, cardiogenic shock)
Probably
- Post extubation ARF prophylaxis (>65, underlying heart/lung disease)
- Post op ARF (supra diaphragm, GI+eso, pelvic *ensure no concern for anastomotic leak)
- Palliative ARF
- Immunocompromised ARF
DO NOT USE
- Non acidotic COPD
- Failed extubation
NIPPV Harms
- Delayed intubation
- Unrecognized deterioration
- Not lung protective
Contraindications to NIPPV
- Facial surgery, trauma
- Dec LOC
- Can’t clear secretions
- Respiratory arrest
- HD unstable
- Indication for intubation
- AGMP!!! Watch for COVID
Goals of mechanical ventilation
- O2 delivery
- A-B homeostasis
- Airway protection
MV improves oxygenation by:
- Increasing FiO2 delivered
- Reducing VQ mismatch - PEEP opens alveoli
- Reduce shunting
Volume control
Trigger: ventilator/time
Target: Flow
Cycle off: volume
Variable: pressure
Pressure control
Trigger: ventilator/time
Target: pressure
Cycle off: time
Variable: volume
ACPC
Trigger: ventilator +/- patient
Target: pressure
Cycle off: time
Variable: volume
ACVC
Trigger: ventilator +/- patient
Target: flow
Cycle off: volume
Variable: pressure
SIMV
Trigger: ventilator +/- patient
Target: varies
Time off: time for variable breaths
Pressure support
Trigger: patient
Target = pressure
Cycle off: flow
Variable: volume and rate
Initial MV Settings
Mode: pressure or volume, assist or control
Tidal volume: ARDS 4-8 cc/kg
RR: except for PS
PEEP, FiO2, trigger, cycle off, alarms/backup
Re assess
ARDS pathophys
Pathophys: - Alveolar damage - Hyaline membrane deposition - endothelial damage/permeability Causes: - Local: PNA, contusion, aspiration - Systemic: sepsis, pancreatitis, drug, TRALI
ARDS definition
- Onset within 1 week of insult
- Bilateral opacities on CXR (pulmonary edema)
- Not due to cardiogenic/vol overload
- PF ratio with PEEP >=5
a. Mild 200-300
b. Mod 100-200
c. Sev <100
ARDS Treatment
- Tx underlying cause
- Provide oxygenation
- Protect the lungs
- ICU best practices
ARDS - Lung protective ventilation
- Tidal volume 4-8 cc/kg (based on predicted weight from height)
- Proning in severe for >12 hrs/day
- Plateau pressure <30
- Higher PEEP/FiO2 if mod-sev
Targets - pH 7.25-7.35
- PaO2 55-80
- O2 sat 88-95%
Pros and Cons of PEEP
Pros 1. Alveolar recruitment 2. Decrease strain on lungs 3. Decrease atelectrauma Cons 1. Alveolar overdistension 2. Intrapulmonary shunt 3. Increased dead space 4. High pulmonary vascular resistance
ARDS with high FiO2
Should use a higher PEEP strategy!
If FiO2 >50%
Mortality benefit in ARDS
Reduce mortality - High PEEP - Prone positioning Equivocal - Recruitment maneuvers (not routine) - NM blockade (consider if PF<150, vent dyssynchrony or difficult lung protection) - ECMO - Diuresis/IVF Increased mortality - High Hz oscillation No benefit - Statins, inhaled NO (bridge, improves oxygenation), steroids
General COVID Recommendations
- AGMP = wear N95, negative pressure room
- Most experienced person intubates
- Use NE>epi>dop
- no hydroxyethyl starches - use crystalloids
- Dex 6 mg IV daily x 10 days
- No interferon, convalescent plasma, HCQ
- Remdesevir controversial
COVID Ventilation Recommendations
- Suggest O2 <92%, recommend <90%
- Target no >96%
- If NIPPV/HFNC monitor closely for deterioration and need for intubation
- Plat pressure <30
- Higher PEEP strategy
COVID O2 Algorithm
- PF >150 = facemask
- PF <150 = intubate
- TV 6, PEEP 10, RR 15, FiO2 1
Weaning from MV
Consider if:
- Reversed underlying cause
- Cardiac stable
- Adequate mentation
- Oxygenation - FiO2<40, PEEP 5-8, PaO2>60
- Other: lyes, A-B, pain control
Spontaneous Breathing Trial
- Attempt to mimic them breathing on their own
- ETT inc resistance = harder than breathing on own
- Should do SBT on pressure support for shorter period of time instead of t piece for longer
- Ex. PS 5/0
- Can estimate RSBI
RSBI
Rapid shallow breathing index
= RR/Tidal Volume
RSBI>105 = failed extubation
RASS
Target RASS -2 to +1 \+4 = combative, violent dangerous \+3 = pull/remove tubes/cath, aggressive \+2 = frequent non purposeful movement \+1 = anxious, apprehensive 0 = alert and calm -1 = awaken to voice, eyes >10 s -2 = lid sedation, brief <10 s -3 = mod sedation, move/open eyes -4 = deep sedation, no response to voice, respond to physical stimulus -5 = unrousable, no response
ICU Sedation Options
- Prefer propofol or Precedex > benzos
- Daily awakening trial
- Stop infusion ASAP
ICU Delirium
Non Pharm
- Sleep, mobilize, hearing/vision aids, orient, daylight, family
Pharm
- Nothing shortens course
- Atypicals preferred ex. quetiapine
- Consider Precedex if preventing weaning/assess extubation
ICU Pain management
- Multimodal
- Tylenol and NSAID
- Opioids esp post op
- Low dose ketamine and lidocaine = adjuncts
- Neuropathic = gabapentin, carbamazepine, pregabalin
- Regional anesthesia- epidural, nerve blocks
ICU Sleep
Non Pharm
- Ear plugs, eyeshade, relaxing music, schedule, light/dark
- NO PROPOFOL
- Unclear Precedex/melatonin
Post arrest TTM
- Any rhythm
- In or out of hospital arrest
- Target Temp 33-36 (or 32-34) –> upper limit if arrhythmia or CV unstable
- Minimum 24 hours, longer if need to prevent fever
Brain death
Irreversible cessation of cerebral and brainstem function
Persistent vegetative state
Severe anoxic brain injury progressing to a state of wakefulness without awareness
No purposeful response
Sleep wake intact
Minimal conscious state
Limited interaction with environment with visual tracking +/- simple commands
Intelligible verbalization or something yes/no but not always appropriate
Locked In
Retained alertness, cognitive abilities, can move eyes and blink voluntarily but paralysis of limbs and oral structures
Neurologic Determination of Death
- 2 physicians
- Etiology compatible with NDD
- No confounding factors: umresuscitated shock, T<34, sev metabolic, NM block, peripheral neuropathy/myopathy, drug interactions **if you can’t correct these then use ancillary testing
- Absent brain stem reflexes - pupillary, corneal, gag, cough, oculovestibular (cold calorics - towards cold)
- Absent movement - spont + noxious (bilateral AND above/below clavicles). EXCLUDES spinal reflexes
- Apnea testing
Apnea testing
- Correct confounders
- Pre oxygenate and get ABG (want CO2 35-45, pH 7.35-7.45)
- Disconnect vent
- Monitor resp efforts
- Serial ABGs
Complete when: - CO2>60
- CO2 >20 above baseline
- pH <=7.28
NDD Post cardiac arrest
Must wait AT LEAST 24 hours before NDD
NDD Confounding Factors
- May over rule by 2 physicians
- Therapeutic anti epileptics don’t count
- Lab recommendations: pH 7.35-7.45, Na 125-159, phos >0.4, Gluc 3-20
Ancillary testing
Want to demonstrate absent cerebral flow. Use this if can't fix confounders. 1. Radionuclide angiography 2. CT angiography 3. 4 vessel angiography 4. MR angiography NOT EEG!!