ICU Flashcards
(162 cards)
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