CRIT CARE Flashcards
Factors that lead to vent-induced lung injury
- volume- pressure- oxygen
Factors that determine oxygenation
- FiO2- PEEP- mean airway pressure
Factors that determine ventilation
- RR- TV*assessed w/ PaCO2
Plateau pressure
measure at inspiratory pause; reflects alveolar pressure (ideal <30)
Peak airway pressure
total amount airway pressure delivered to overcome resistive and elastic work; if high represents large airway obstruction or bronchospasm, etc
Tobin index
rapid shallow breathing index = RR/TV; if <100 good indicator pt may come off vent (if <65, 90% sensitivity)
Negative inspiratory force (NIF)
expiratory pause - check neg pressure that pt can generate in lungs; if <20 then unlikely to be able to extubate. predictor of failure (not a good predictor of success)
ARDS Berlin definition
PaO2/FiO2 ratio + within 1wk insult + CXR + not due to fluid overload (check Echo)mild: 200-300mod: 100-200severe: <100
MOA dopamine
dose-dependentlow -> dopaminergic receptor in kidneysmed -> B1high -> alpha
MOA NE (levo)
alpha (B1 at low doses)
MOA Epi
equal alpha + B1
MOA phenyephrine
pure alpha (typically only to treat neurogenic shock 2/2 spinal cord injury)
MOA vasopressin
acts on V1 (vasopressor receptor)
MOA dobutamine
more B1 (good for cardiac failure), but has some B2 vasodilatory effect (no alpha)
MOA milrinone
PDE inhibitor; increases cAMP -> increases CO, vasodilatory
EKG change in PE
S1, Q3, T3; MC is sinus tachy
CVP tells us…? By measuring…?
volume status; by measuring RVED pressure
Wedge pressure tells us…? By measuring…?
preload; by measuring LVED pressure
Equation: CO
CO = SV x HR
Equation: CI
CI = CO/patient BSA
Equation: O2 delivery
O2 delivery = 1.36 x O2sat x (CO x Hgb)
Equation: O2 consumption
O2 consumption = (O2 arterial - O2 venous) x CO
Direct thrombin (Factor 2a) inhibitors
dabigatran, argatroban
Equation: respiratory quotient
RQ = CO2 produced/O2 consumed
RQ >0.9
giving too many carbs and cannot get off vent
TPN ratio of carbs vs. fat
Carbs 75%, 25% fat
Essential fatty acids
- linoleic- alpha linoleic
Caloric content of carbs? lipids? protein? dextrose?
carbs = 4 kcal/glipids = 9protein = 4dextrose = 3.4
Airway pressure release ventilation
long inhalation period to open airway, then short period where pressure drops and pt allowed to exhale (pressure never 0)
Post-intubation initial tidal volume is…?
5-7 mg/kg
Neuroleptic malignant syndrome sxs
muscle rigidity, obtundation, tachycardia, fever
Mgmt neuroleptic malignant syndrome
bromocriptine, dantrolene
Drugs at risk neuroleptic malignant syndrome
haldol, metoclopramide
What kind of Cx ordered for BAL to dx vent-associated pneumonia?
quantitative cx (threshold 10^4 used to dx)
Absolute C/I bronchoscopy
severe refractory hypoxia w/ inability to maintain adequate oxygenation during procedure (cx of sedation and partial airway obstruction)
How to ventilate ARDS pts
- low TV (4-6)- PEEP titrated to keep alveoli open- permissive hypercapnia (as long as pH >7.2)
If ARDS pt failing conventional therapy, what other method therapies with proven benefit?
- proning (will improve P/F ratio)- neuromuscular blockade
New definition of sepsis
Sepsis 3 = if >2 increase SOFA score (sequential organ failure assessment)
Definition of septic shock
pt that needs pressor support to maintain MAPS >65 AND who has sustained lactate >2 (despite resus)
Mgmt sepsis resuscitation
within 3 hrs -> Cx, Abx, trend lactate (to guide resus), bolus w/ 30cc/kg for lactate >4within 6 hrs -> start pressors to maintain MAPS, look at tissue perfusion, guide resus based on lactate
Use for procalcitonin in ICU
indicates bacterial infection- when normalizes can think to stop Abx- if normal, can r/o sepsis- if elevated, ?? bc sensitive, not specific
Tests for invasive candidiasis
- 1,3 beta-D-glucan- mannin- anti-mannin Ab
Where do you draw mixed venous O2?
pulmonary artery
RQ gives idea of what fuel pt is burning… so what is RQ for fat? protein? carbs?
fat = 0.7 protein = 0.8 carbs = >1.0
Equation: nitrogen balance
nitrogen IN (protein in g/day via protein/6.25g) - urine loss - 4 (insensible loss)
Adverse effects too much carbs
high RQ -> difficult wean venthyperglycemiaimmunosuppressant effect
Adverse effects of too much fats
pro-inflammatory
How much protein generally give pts? in renal failure pts? in liver failure pts?
1g/kg/day renal -> ensure have essential AAliver -> branch chain AA
MC long-term pulmonary defect of ARDS
reduced diffusing capacity (DLCO) 2/2 replacement of type 1 lining cells by cuboidal cells + pulm fibrosis
Allen test used to…?
determine if ulnar artery can provide distal perfusion to hand
Mechanism of IABP
- inflation during diastole -> increased MAP2. rapid deflation just prior to systole -> decreases afterload on heart
MC organism vent-associated pneumonia
sensitive GP (MSSA, strep sp) and H.influ
Which location for arterial catheterization are at higher risk thrombosis?
brachial and radial (but easier to cannulate and less risk to injury to nerves)
Effect of permissive hypoventilation for ARDS pts
- duration of mech vent support longer, but greater survival%- can disregard pCO2 unless pH <7.28 or ICP >15- C/I head injury pts w/ elevated ICP
Pathophysiological changes associated with development of ARDS
2/2 diffuse alveolar damage; diffuse inflam causing…- increased vasc permeability -> hypoxemia + diffuse b/l alveolar infiltrates on XR- alveolar edema- acute inflam of alveolar walls- hyaline membranes
Standard confirmation of ET tube is with…?
end-tidal CO2 detection - CO2 released from lungs after initial 3-4 breaths
How to measure intra-abdominal pressure re: abd compartment syndrome?
bladder pressure @ end-expiration:- instill 70cc saline into bladder via clamped foley- pressure transducer via needle in aspiration port
Settings in which PA cath is still used
- RV failure- pulm HTN- weaning failure of cardiac origin- post-cardiac surgery
Normal cardiac index (PA cath)
2.5-4 L/min
How does trauma affect tissue O2 consumption?
decreased. trauma -> decreased cardiac output -> decreased tissue perfusion
Mgmt air embolism
prevent air from entering RV (LL decubitus + Trendelenburg), then aspirate air from cath and place on 1.0 FiO2 to attempt reabsorption of air
Does septic shock respond to vasopressors?
No. hypotension 2/2 failure of vasc smooth muscle to constrict bc upreg of iNOS in vessel walls, which lasts for sustained time, rending vasoconstrictive agents ineffective