Critical Care Flashcards
Cardiac tamponade: How does it make that cardiac tracing look?
Exaggerated X descent (RA and RV are affected first) and attenuated Y descent.
What type of anesthesia could you give for tamponade?
What should you avoid?
Ketamine. Keep ventilation spontaneous.
Cardiac depression, vasodilation, and slowing of the heart rate should be avoided. Acute loss of preload, contractility, and heart rate can cause catastrophic circulatory collapse in the setting of cardiac tamponade. Epinephrine, therefore, is a useful medication in the management of cardiac tamponade and an infusion should be considered prior to induction of anesthesia.
How to think of management for tamponade:
Hemodynamic goals for cardiac tamponade are best described as keeping the patient fast (tachycardia), full (hypervolemia), and tight (increased SVR). DO NOT SLOW HEART RATE!
Constrictive pericarditis on CVP waveform:
Constrictive pericarditis causes an exaggerated X-descent and Y-descent on the CVP waveform.
The key features of botulism syndrome:
B/l cranial nerve deficits
Treatment of botulism: Above 1 and under one
Two types of antitoxin therapies are available – equine serum in patients older than one year old and human-derived immune globulin for infants less than one year of age.
Formula to figure out how to neutralize acids by using sodium bicarbonate
Sodium bicarbonate (mEq) = 0.2 * patient weight (kg) * base deficit
In patients with respiratory depression, can you give Bicarbonate?
Sodium bicarbonate should not be administered to a patient with respiratory depression or respiratory failure unless the patient is mechanically-ventilated
In true pressure support mode, there is no ____. This means ___
In true pressure support mode, there is no backup rate; thus hypoventilation can occur particularly with a low respiratory rate.
What are the 5 causes of hypoxemia?
Hypoventilation Low Partial pressure of O2 VQ mismatch poor diffusion right to left shunt
Of the 5 causes of hypoxemia, which ones do NOT result in increased A-a gradient?
Hypoventilation and low partial pressure of O2.
Classical finding of impaired diffusion (A-a stuff)
The classic clinical finding suggestive of impaired diffusion is a normal PaO2 at rest but a decreased PaO2 with increased cardiac output.
T/F: A right-to-left shunt is never associated with an increased A-a gradient.
FALSE! It is always associated with an increased A-a gradient.
Organophosphate poisons-how do they hurt? How do the modes of paralysis switch?
Organophosphates and related poisons including sarin nerve gas are acetylcholinesterase inhibitors that permanently bind to and prevent the function of the enzyme. This initially leads to a buildup of ACh within the neuromuscular junction resulting in brief spasms or a spastic paralysis. However, pre and post-junctional structures are soon destroyed, possibly due to the accumulation of toxic levels of calcium from continued stimulation, and a longer-lasting flaccid paralysis will result.
Why make patients prone in ARDS?
Better VQ matching
Improved FRC
better drainage of secretions
4 types of shock:
Cardiogenic, obstructive, distributive, hypovolemic
Explain obstructive shock: whats usually happening?
Obstructive shock generally occurs in four clinical scenarios: tension pneumothorax, anterior mediastinal mass, pericardial tamponade, and pulmonary embolism. Since venous return to the heart is obstructed, central venous pressure (CVP) is elevated. Cardiac output (CO) is decreased. Systemic vascular resistance (SVR) is increased to compensate for reduced cardiac output.
Why is PA occlusion pressure elevated in some types of shock, but not in others?
Because with ptx, mediastinal mass, and tamponade pulmonary artery occlusion pressure should be elevated. In PE-might not be elevated due to the fact that it tends to only affect the right side of the heart
Cardiogenic shock: CO: CVP: SVR: PAOP:
Cardiogenic: CO is decreased, CVP is elevated, SVR is increased, and PAOP is increased.
Distributive shock: What is it? CO, CVP, SVR, and PaOP?
Distributive shock is a failure of the vasculature to generate adequate SVR. In distributive shock, CVP is low, PAOP is low, SVR is low, and CO is high. Common causes of distributive shock are septic shock, anaphylactic shock, and neurogenic shock.
Hypovolemic shock and CO,CVP, SVR, and PAOP:
Hypovolemic shock results from intravascular volume depletion. The body has a decreased preload (CVP and PAOP) as the primary hemodynamic derangement. Hypovolemic shock results in decreased CO, increased SVR, decreased CVP, and decreased PAOP.
When, in brain death is confirmatory testing needed?
Only if the patient is under the age of 1
Criteria for brain death:
Criteria are: two physician evaluation, no other causes that mimic brain death, coma with absent brainstem reflexes, and lack of respiratory drive by apnea testing.
Other than age, when would you need a confirmatory test for brain death?
Confirmatory testing for brain death may be required in situations where clinical evaluation is compromised (severe facial trauma, pre-existing neurologic derangements prior to the incident) or where apnea testing is contraindicated such as significant hemodynamic instability, metabolic acidosis, or high levels of ventilatory support
Sepsis: How much fluid? Abx? Target MAP in sepsis?
Patients demonstrating sepsis-induced hypoperfusion should be initially resuscitated with at least 30 mL/kg of intravenous crystalloid within the first three hours. ABx-should be started at least 1 hour within finding out. Target MAP in sepsis: 65
which blood products have the lowest risk of TRALI? Why?
PRBCs-because the plasma fraction is removed
Which two products have the highest incidence of TRALI?
Plasma products and platelets: FFP, Cryo, platelets. Rb question that asked which person would be more likely to get TRALI, you’d also have to know which products they would require.
How is magnesium cleared?
the kidney.
Non-iatrogenic causes of hypermagnesemia:
Non-iatrogenic causes of hypermagnesemia include adrenal insufficiency, diabetic ketoacidosis, hemolysis, and hyperparathyroidism.
which 3 drugs are so broad spectrum that they can even treat gram negatives?
eftaroline, tigecycline, and TMP-SMX have the broadest spectrum of activity effecting both Gram positives and some Gram negatives
Early onset adult VAP is typically due to:
antibiotic-sensitive flora (Methicillin-sensitive Staphylococcus aureus (MSSA), H. influenzae, S. pneumoniae, and Proteus, Klebsiella, and Enterobacter species) and does not typically affect morbidity and mortality
Resuscitation of the drowning victim begins with: ____. Do NOT do what?
Rescue breaths FIRST, then chest compressions. DO NOT attempt to expel water from the lungs
classic clinical findings in cardiogenic shock: (6)
classic clinical findings in cardiogenic shock include (1) low cardiac output with jugular venous distension, (2) hypotension with peripheral and pulmonary venous congestion, (3) peripheral vasoconstriction, (4) cool extremities, (5) poor urine output, and (6) altered mental status.
Is the microcirculatory system preserved in cardiogenic shock?
No. Think about the fact that the oncotic pressures and all that stuff are changing.
Charcot Marie Tooth and Vincristine?
Avoid the two because ppl with CMT already have peripheral nerve issues
Cyclophosphamide can cause what?
hemorrhagic cystitis
Mercapotpurine and gout
Mercaptopurine is metabolized by xanthine oxidase. Xanthine oxidase is inhibited by Allopurinol, so if you have a patient with gout then be careful because the mercaptopurine can build up
Side effects of Transtuzumab and 6MP and methotrexate;
Trastuzumab: cardiotoxicity
5-FU, 6-MP, methotrexate: myelosuppression
4 Sites are recommended for IO:
he sternum, proximal tibia, distal tibia, and proximal humerus
Is there a difference in flow between humeral IO and tibial IO? complications of IO?
Humeral IO lines support almost twice the flow rates of tibial IO lines. Complications are rare, and they are easier to place than central.
What does an ABG and VBG show in cyanide toxicity as far as O2 and metabolic state?
An arterial blood gas analysis in a patient with cyanide toxicity may show normal oxygenation with metabolic acidosis; although depending on the time from exposure, the metabolic acidosis could be masked by respiratory compensation. A venous blood gas may reveal a high oxygen content, which may mirror that of the arterial blood gas, because oxygen is not being utilized for cellular respiration.
Role of sodium thiosulfate in cyanide toxicity?
Sodium thiosulfate was administered secondarily to remove the cyanide from the methemoglobin.
Why is sodium thiosulfate not really used anymore with cyanide toxicity?
Though previously a common treatment of cyanide toxicity, this approach had several problems: nitrites can precipitate hypotension and methemoglobinemia, with the latter being toxic.
So, what do we use now to tx cn toxicity?
Hydroxocobalamin works by combining with cyanide to form cyanocobalamin (vitamin B-12). Cyanocobalamin is renally cleared. The use of hydroxocobalamin became first line due to its low adverse risk profile, rapid onset of action, and ease of use in the prehospital setting;
If you cant find hydroxocobalamin, what can you give for CN toxicity? What if you have no IV?
amyl nitrite if no iv, and sodium nitrite -but both of these have fallen out of favor due to hypotension
How can cefepime directly cause worsening hypotension in a patient with pan-sensitive E. coli bacteremia?
LPS. efepime (and any antibiotic used to treat Gram-negative bacteria) may directly cause lysis of the outer bacterial membrane composed mainly of lipopolysaccharide (LPS)-it can release nitric oxide
What can vanco release that causes hypotension?
Histamine
Hydrocortisone is not indicated in the treatment of septic shock unless: ____. If you do give them, then how much do you give? Can you give steroids in anticipation of septic shock?
No steroids in septic shock unless patient not responsive to fluids or vasodilators. If given, give Hydrocortisone 200 mg IV per day should be administered; it can then be tapered once vasopressors are no longer required. Steroids are NOT recommended for patients with septic shock responsive to fluids or vasopressors nor are they indicated for sepsis in the absence of septic shock.
Hydrocortisone inhbiits what?
Nitric oxide synthesis.
T/F Blood should NOT be administered through the same line as TPN using Y-site or piggyback connections. Why or why not?
TRUE. It should not be administered through the same line as TPN. Because because dextrose causes hemolysis of red blood cells.
When taking patients on TPN back to the OR, what is critical to check? should you continue it? How can TPN affect CHF patients?
Electrolyte levels, liver enzymes (TPN can cause liver dysfunction). you should continue TPN if possible d/t hypoglycemia with rapid d/c of TPN. TPN can affect CHF patients by causing volume overload.
What is the alkaline drift seen in CPB?
here is a natural “alkaline drift” with hypothermia owing to the increase in gas solubility and reduction of the PaCO2.
pH stat mgmt: wht does it do as far as the alkaline drift?
A pH-stat management technique corrects the alkaline drift by maintaining a neutral pH during hypothermia.During pH-stat management, CO2 is added to the oxygenator or the CPB “sweep” may be reduced (the sweep mechanism removes CO2 from the CPB circuit). The addition of CO2 to the circuit increases total body CO2 in order to maintain pH neutrality despite the continuous reduction in core temperature.
What about alpha stat: What does it do as far as the alkaline drift?
Alpha-stat management allows the natural alkaline drift to occur without correction.
ALPHA IS DOWN FOR ALKALINE! IT’S NOT TRYING TO CHANGE IT!
Advantages of pH stat: Disadvantages?
increased speed of homogenous cerebral cooling through cerebral vasodilatation, reduced cerebral metabolic rate of oxygen demand (CMRO2) while providing increased cerebral blood flow (CBF), and improved oxygen delivery to tissue by counteracting the leftward shift of the oxyhemoglobin curve typical of alkalosis. Disadvantages of pH-stat management include an increased delivery of embolic load to the brain as a result of the cerebral vasodilatation as well as loss of cerebral autoregulation. Outcome data support the use of pH-stat management during congenital heart surgery as a result of the homogeneous brain cooling.
What is qSofa? why would anyone use qSofa?
qSOFA criteria are scored from 0-3 with one point for each of the following: altered mental status (GCS < 15), respiratory rate ≥ 22, and systolic blood pressure ≤ 100 mm Hg. can be used to identify adult ICU patients with a suspected infection that are likely to have a prolonged ICU stay or poor outcome. It may also be used in adult out-of-hospital, emergency room, and general ward patients with suspected infection to identify those that are more likely to have poor outcomes typical of sepsis.
What is a NM blocking drug whose metabolite is nearly as potent as its parent drug? whats the metabolite and who is at risk for it building up?
Vecuronium. 3-desacetyl metabolite is the most important since it has nearly 80% of the activity of vecuronium. It can accumulate in the setting of vecuronium infusions, particularly in patients with renal disease since this metabolite is renally cleared
Cisatricurium and atracuium metabolites
Cisatracurium (and atracurium) is primarily metabolized (80%) to laudanosine. This renally-cleared excitatory amine can precipitate seizures, but does not have neuromuscular blocking activity. The clinical significance of laudanosine was more important with atracurium
Best C diff test :
C. difficile bacterial antigen EIA can rapidly detect the presence of the bacteria, although asymptomatic carriers will also be positive.
First line of treatment forreating hyperkalemia with mental status and EKG changes is: _____. Why not CRRT?
to stabilize the myocardium with calcium to prevent a malignant arrhythmia and cardiac arrest.nsulin is administered in conjunction to temporize the potassium levels by causing intracellular influx. Dextrose is supplemented to prevent hypoglycemia with insulin administration.Continuous renal replacement therapy is the correct definitive treatment. In the setting of mental status and ECG changes, however, myocardial protection is the most urgent and best next first step.
Cardiogenic shock due to MI parameters:
SBP
PCWP
CI
The hemodynamic parameters seen are sustained hypotension for longer than 30 minutes with a systolic pressure less than 90 mmHg (or a decrease from baseline of 30 mmHg), a pulmonary capillary wedge pressure greater than 18 mmHg, and a cardiac index of less than 2.2 L/min/m^2.
What is the primary method of increasing oxygen delivery to the body at high altitude? Why does this happen? Initially what? then after a few days? What does this do to the body’s pH and PaCO2?
increased minute ventilation as a result of hypoxic stimulation of peripheral chemoreceptors. Initially, this causes a respiratory alkalosis, however, after a few days the body compensates by increasing the bicarbonate loss in the kidneys. This helps normalize the body’s pH, but the PaCO2 remains low.
T/F Minute ventilation starts to normalize after a while at high altitude? How does minute ventilation increase?
False. It stays high the entire time someone is at high altitude. RR rate increases, but VC and FRC stay the same.
Why is altitude weird-like, what makes things more difficult? Is the concentration of oxygen the same? What about the vapor pressure?
because the drop in barometric pressure at higher elevations results in a lower partial pressure of oxygen. Although the concentration of oxygen and vapor pressure remain the same, according to the alveolar gas equation, when the barometric pressure falls there is a decrease in alveolar oxygen
Does the partial pressure of water vapor change with high altitude?
No.
CO and high altitude?
It increases in order to improve oxygen delivery to the tissue the cardiac output increases as well.
Protein metabolism during the stress response.
First there is anabolism and THEN, there is catabolism. Lipid catabolism is part of the stress response, and so is catabolism from visceral muscles.
What part of the body does the ACA supply?
and 4 parts of brain
medial surface of the parietal lobe, which includes part of the primary motor cortex. The part of the cortex which is located medially, is that which gives motor function to the lower limb
- 4 parts
- Prefrontal cortex: functions in motivation, planning, and organizing of complex behavior
- Supplemental motor area (dominant cortex): functions with Broca’s area for speech
- Motor cortex (lower limb)
- Sensory cortex (lower limb)
ACA stroke would lead to:
Anterior cerebral artery strokes tend to lead to behavioral abnormalities, aphasia (if dominant cortex is involved), and contralateral lower limb weakness and sensory deficits.
What is the purpose of phrenic nerve stimulators? Who gets them? What are the complications?
Phrenic nerve stimulators improve lung function and reduce atelectasis in patients with cranial or cervical spinal cord injuries but have multiple known complications.
Infections, injury of cervical electrodes during neck motion, paradoxical inward movement of chest in peds, infection
Go over chart of what is broken down/activated in lungs
Okay. Epi is not, histamine is NOT, angiotensin 2, oxytocin, and vasopressin are NOT, dopamine is not and pg1 and pg2 are not
Why do people with myotonic dystrophy have so many issues with possible aspiration?
Patients with myotonic dystrophy have an increased risk of pulmonary aspiration due to gastric atony and delayed emptying, intestinal hypomotility, and pharyngeal muscle weakness.
Any form of carotid sinus manipulation, such as carotid stent deployment, may result in stimulation of carotid baroreceptors located within the carotid sinus. This results in
sympathetic inhibition.
The AFFERENT NERVE involved is #9-glossopharyngeal
The body receives chemo
this means that the chemoreceptors are in the carotid body, and the carotid sinus has the baroreceptors (sinus bradycardia)
What is mixed venous oxygen saturation in sepsis-increased or decreased? Why? What about microvascular shunting?
Increased-due to increased cardiac output. Microvascular shunting will also lead to increased MV O2
Uterine blood flow pre pregnancy vs at term
normal flow pre-pregnancy is approximately 50 to 100 mL/min with an increase up to 900 mL/min at term.
Does CSF bicarbonate decrease with altitude sickness?
Yes. It goes into bloodstream (2-3 days later) and then is excreted through urine.
can you get cerebral edema from high altitude?
High altitude cerebral edema (HACE) may be caused by a significant increase in cerebral blood flow leading to hyperemia in the setting of hypoxia.
