OA Critical Care part 2 Flashcards
Clearance is:
Fraction of drug eliminated from the body per unit of time.
Volume of Distribution: _____. In other words:
volume that the amount of administered medication would have to occupy, if uniformly distributed to achieve the same concentration as the current plasma concentration. In other words, a larger VD implies that the drug is more dilute than it should be. It essentially describes distribution between plasma and other body tissues.
How does metabolism work in burn patients?
Well first-hypodynamic state (burn shock), followed by hyperdynamic state with anasarca/edema that can last for months.
How does propofol work in burn patients in the hyperdynamic state? Clearance? Volume of distribution?
They usually require more, and their drug clearance is generally increased, and volume of distribution may increase due to enlarged extracellular fluid volume, or due to decreased protein binding.
What happens to albumin and alpha 1 acid glycoprotien in burn patients?
albumin decreases (giving drugs bound to allbumin increased bioavailability), and AA1g increases, giving drugs bound to it decreased bioavailability.
How do PEEP and CPAP affect the extravascular lung water?
No net effect, just redistribution of extravascular lung water to peribronchial and perihilar areas from interstitum between alveoli and endothelial cells
What are indications for TPN:
inability for sufficient nutritional/caloric intake to be absorbed via the GI system (short gut syndrome, small bowel obstruction, acute GI bleeding, pseudoobstruction and high output entercutaneous fistulas)
Pyloric or post pyloric feeds:
no real reason to prefer one over the other unless there’s an anatomic thing.
FENa greater than 3%=associated with: ____. BUN: Cr ration greater than ____ assoc with pre-renal causes of kidney injury. What is the BUN:cr ratio in ATN?
ATN. Cr greater than 20:1, then likely pre-renal. In ATN, BUN: Cr ratio typically less than 15.
Name 3 disadvantages to administering stress ulcer prophylaxis to patients in the ICU?
Increased incidence of PNA, increased incidence of c diff, thrombocytopenia
How does resuscitation for a drowning victim differ than that for a regular victim?
for drowning, you give 2 rescue breaths first (ABC), whereas in other situations, its CAB (circulation (compressions), airway, breathing).
Tell me about the RQ for ppl eating fats, carbs, proteins. What is RQ?
RQ: ratio of CO2 eliminated/O2 consumed. 0.7-1,0 is the range. 1.0=pure carb metabolism. 0.8=proteins, 0.7=pure fat metabolism.
What’s required for a diagnosis of brain death? (FOUR steps):
STEP one: Clinical evaluation: Establish reversible cause of coma Exclude CNS depressants and NMBs Normal temperature (>36) Normal SBP (>100) Single neuro exam after sufficient time period has passed since injury STEP two: Neurologic exam: -unresponsive coma -no cranial nerve reflexes -Apnea (PCO2>60, or >20 over baseline STEP three: -Ancillary testing like EEG or cerebral blood flow study STEP four: -documentation -contact organ procurement
Are spinal reflexes permitted in brain death?
Yes. Spinal reflexes do not mean a patient can not be brain dead
Apnea test must meet which criteria:____. If apnea test can’t be done, what ancillary test is the gold standard and why?
HDS, ventilator adjusted to normocarbia, patient pre-oxygenated with 100% FiO2 for >10 minutes to PaO2>200 and with a peep of 5. If apnea testing can’t be performed, ancillary tests can be done: Cerebral angiography is the gold standard-it is not affected by CNS depressant drugs or hypothermia.
What is needed to make dx of Pul HTN? (3 things)
Right heart cath confirmation of: Resting mPAP >25 mmHg, PCWP/LAP<15, and PVR >3 woods units
Use of insulin therapy in ICU in patients with subarachnoid hemorrhage is associated with :
hypoglycemia
HIT is what, and is characterized by what:
PRO-THROMBOTIC immune mediated disorder where IgG platelet activating abys are formed against Platelet factor 4. Characterized by >50% reduction in platelet count that typically occurs 4-10 days after intiation. of heparin (any type-unfractionated most common)
Type I vs type 2 HIT
Type 1: non-immune mediated. type 2: can lead to catashropic thrombosis.
Key interventionin HIT:
ALL HEPARIN (even flushes) MUST BE STOPPED!
What to do if patient has PE and gets HIT?
Switch to a direct thrombin inhibitor: argatroban.
Why is warfarin contraindicated early in HIT?
Due to risk of warfarin necrosis. because protein c gets depleted first, leading to microthrombosis, and also-warfarin prolongs the aPTT which predisposes to underdosing of direct thrombin inhibitors monitored with aPTT
Explain the rule of nines
In adults: Head is 9% Anterior torso: 18% Posterior torso: 18% Each arm is 9% Each leg is 18%
NMS vs serotonin syndrome: ____. What causes NMS?
NMS: elevated cpk due to rhabdo. NMS risk: those taking antipsychotic and neuroleptic meds that abruptly d/c them.
What causes Serotonin syndrome?
increased serotonergic activity in CNS leading to AMS and agitation. Tx: d/c of serotonergic meds, benzos, and IV cryptoheptadine (serotonin antagonist). Agitation, hyperreflexia, hyperthermia
if you change expiratory time from 1:1 to 1:3 during VCV? Which physiologic changes will happen?
Increased inspiratory flow (makes sense because more volume has to go in with less time
Normal I:E ratio ranges from:
1:2 to 1:4
With higher I:E ratios (1:1 compared to 1:2) shows what as far as peak airway pressures? What other physiologic changes?
Lower peak airway pressures., also-decreased phsyiologic dead space, higher meanairway pressures and increased dynamic compliance.
How much fluid shouldyou give for first 24 hours in burn patients?
4 mL/kg x the percentage of body surface area burned. Give the FIRST half in the first 8 hours, and the 2nd half in the next 16 hours. Only used for 2nd and 3rd degree burns
Lethal triad in trauma
acidosis, coagulopathy, and hypothermia
why coagulopathy in trauma?
thought to result from hemodilution that occurs with aggressive fluid administration, coupled with consumptive loss of coag factors.
Risk for development of hyperkalemia appears to be highest at __ to __ after injury:
10-50 days, but can persisit for 1-2 years after injury.
Benefits of Prone positioning in ARDS?
Increases FRC and improves thoracoabdominal compliance. secretions drain away from the mouth=decdreased ventilator assoc pna. Also-improved oxygenation
Findings of ethylene glycol (antifreeze) poisoning?
Metabolic acidosis with high osmolar gap, calcium oxalate crystals are in urine
Ethylene glycol is metabolized by: ____ and so how would you treat it?
Metabolized by ADH to glycoaldehyde and glycolic acid (both of which nephrotoxic and can slow the metabolism of ethylene glycol). Treat by blocking ADH (fomepizole). Ethanol can competitively inhibit ADH inhibiton. Thiamine and Vit B6 can be given
Nitric oxide (NO) does what? How? How long does it last?
its a vasodilator via cGMP. It dilates the pulmonary arteries. Peak effect: 3 minutes, d/c effect in 3-6 minutes. It is quickly absorbed and inactivated by hemoglobin.
Why should you NOT suddenly d/c NO?
Rebount hypertension.
Synchronized cardioversion is done in which phase? Why?
QRS-at the peak of the R. It wants to avoid the T wave-during repolarization, or else an R on T phenomenon can happen causing v. fib.
Defibrillation is given:
Pulseless v tach or v. fib
Why can oliguria happen pre-op and post-op?
Hypovolemia, hypotension, manifestation of surgical stress response.
Why are BUN and Creatinine (not Cr clearance) not good to assess renal fxn?
So many other things can happen: BUN is affected by increased protein catabolism (GI bleeding, trauma, steroids). Creatinine can be affected by: muscularity, protein intake, catabolic state. Creatinine CLEARANCE provides most accurate assessment of renal function.
Patients with intracranial injury may initially be ___ (bp), but then can change to ___ with brain death.
Hypertensive due to Cushing’s response. Hypotension and brady with brain death.
What is Cushing’s response?
HTN, apnea, bradycardia
What can you give in brain death to increase blood pressure and improve the survival of transplanted organs?
T3-it can enhance sympathomimetic response. (some places give vasopressin). KIM DDAVP is used for DI
IV Port disinfection had led to decreased ____ infections
decreased central line infections associated blood stream infections.
Amino acid frequently enteral feeds? why? What’s one that helps with the immune system?
Glutamine-indicated in ppl with trauma or burns. Helps to maintain intact gut mucosa. L arginine helps with the immune system.
RBC:FFP:Platelets ratio during massive transfusion
1:1:1. Why? to prevent anemia, diluting of clotting factors and fibrinogen
What’s in cryo?
Factor 8, VWF, Fibrinogen
Who is therapeutic hypothermia good for?
Cardiac arrest after VF or non v-fib related arrhythmias , and people who remain comatose even after ROSC.
Contraindications for therapeutic hypothermia?
Intracranial hemorrhage, severe extracranial hemorrhage, sepsis, hypotension, pregnancy, Trauma associated cardiac arrest, DNR
what’s an alternative to central venous oxygen saturation in sepsis?
Lactate clearance. Target is >10% in over at least 2 hours.
Explain pressure support: What supplies the inspiratory pressure? Who sets the rate and generates flow?
Ventilator supplies supplemental inspiratory pressure to each of the patient generated breaths.(so, it’s flow triggered) The patients sets the respiratory rate, and generates their desired flow rate.
With pressure support, the applied pressure is turned off when:
The flow decreases to a predetermined percentage point.
What dictates the tidal volume? What controls ventilation?
Pressure support given, patient effort, and lung compliance. Flow cycle ventilation
In order for ARDS to be dx, what has to be a ventilator setting?
PEEP or CPAP >5
CRRT vs HD in sick patients:
HD does allow for the removal of large amounts of fluid and rapid correction of electrolyte abnormalities, BUT this rapid correction may not be cool in critically ill, hypotensive, or hypovolemic patients. CRRT allows for more effective urea and solute clearance in addition to more controlled fluid removal. KIM HD standard practive is to give a little heparin for ppl.
Patient related risk factors for the development of perioperative pulmonary complications:
COPD, Age >60, ASA greater than or equal to 2, functionally dependent, heart failure, or albumin <3.5 (poor nutritional status)
Surgery related risk factors for perioperative pulmonary complications:
surgery length >3 hours, abdominal surgery, thoracic surgery, vascular surgery, head and neck surgery, neurosurgery, emergency surgery, and general anesthesia.
T/F Nocturnal oxygen use alone increases your risk of perioperative pulmonary complications
False
Of all the ventilation modes, which one results in a higher PaO2?
Pressure control-Higher lung volume in early inspiration maintains alveolar recrutiment (its a decelerating flow)
T/F Combination antimicrobial therapy is helpful in patients with MRSA
False. use vanc for VaP
SIRS:
Presence of 2 or more of the following:
- Body temp >38 or less than 36
- HR greater than 90
- RR greater than 20 or PaCO2 less than 32
- WBC greater than 12k or less than 4k
Is BP part of SIRs?
No
HFOV (high frequency oscillatory ventilation) in ARDS
reduces ventilatory trauma at level of alveoli, but not better than our current standards in ARDS
How does PSV improve spontaneous breathing?
It lengthens the expiratory phase, decreases respiratory rate, and improves synchrony with the ventilator
Patients with TBI who are hypothermic should NOT be actively rewarmed
TRUE-they should not be due to rebound hypertension
GBS: _____. Treatment:
Ascending Paralysis. Treatment: IVIG
Signs of Infection on UA in the NORMAL population:
Leukocyte esterase and nitrites. In patients in ICU, that can be present even in the absence of infection.
What does sodium bicarbonate do to pH, PaCO2, MAP, and CI?
Raises pH and PaCO2, and does nothing MAP or cardiac index
Pharmacokinetics of lorazepam are not affected:
age, renal disease, or sex-unlike others
Does VA ecmo depend on cardiac contracton?
No
Prinicipal advantage of biphasic vs monophasic waveforms:
Less energy in biphasic, which= less mycoardial injury.
Arginine does what (as far as enteral nutrition)
Stimulates GH, Insulin like growth factor, and insulin to promote the synthesis of protein and wound healing.
What are the two INDEPENDENT risk factors for stress ulcers?
Coagulopathy and >48 hours of mechanical ventilation
Which abx are implicated in the development of hemolytic anemia? Can cause what?
Piperacillin, cefotetan, ceftriaxone . Can cause a postive direct Coomb’s test
