PreTest Surgery: Critical Care: Anesthesiology, Blood Gases, and Respiratory Care Flashcards
Describe the criteria for successful extubation.
- Correction of the underlying pathology
- Hemodynamic stability
- Rapid shallow breathing index (the ratio of respiratory rate to tidal volume) between 60 and 105
- Negative inspiratory force greater than - 20 cm H2O
- Weaned to 5 cm PEEP
- Spontaneous breathing less than 20
____________ should not given to those with air-trapping pathologies because it is less dense than air and can get trapped in those cavities.
Nitrous oxide
Avoid this in those with SBO and pneumothorax.
List the criteria for diagnosis of ARDS.
- PaO2/FiO2 less than 200
- Bilateral chest infiltrates
- PCWP less than 18
What conditions cause a right-shift in the oxygen-dissociation curve?
A right shift means that oxygen is offloaded more easily:
- Acidosis
- Increased temperature
- Increased BPG
Explain the dosing tiers of dopamine.
- Low-dose: dilates the renal and mesenteric vasculature which increases perfusion
- Medium-dose: inotrope
- High-dose: increases SVR
A patient receives plasma and then becomes hypoxemic. What happened?
TRALI: transfusion-related acute lung injury
To treat this, stop the transfusion and intubate.
True or false: give dobutamine to those with cardiogenic heart failure and signs of myocardial ischemia.
True
Because dobutamine primarily affects inotropy and not chronotropy, it only moderately increases myocardial oxygen demand.
The proper treatment for acalculous cholecystitis is _______________.
percutaneous drainage
PEEP affects which lung capacity?
It increases FRC. In ARDS, alveoli close and thus decrease the ERV. PEEP keeps the alveoli open and increases ERV (and thus FRC).
In cardiac tamponade, what might Swan-Ganz catheterization show?
Equalization of pressures across all four chambers
Risk of a cardiac event during a surgery is given by major, intermediate, and mild factors. List some of each.
•Major:
- Unstable angina
- Recent MI (less than 6 months)
- Decompensated CHF
- Severe valvular disease
- Significant arrhythmias
•Intermediate:
- Diabetes
- Mild angina
- Compensated CHF
- Renal insufficiency
• Minor:
- Advanced age
- Abnormal EKG
- Prior CVA
- Uncontrolled HTN
What BP and HR pattern is characteristic of neurogenic shock?
Hypotension and bradycardia
Neurogenic injury (such as spinal trauma) causes a loss of sympathetic input to the vessels and thus a lowering of BP. The heart normally increases in hypotensive states, but that pathway is also through the spine so is lost.
How do you treat neurogenic shock?
1) Fluid bolus
2) Phenylephrine or dopamine
If you suspect air embolism in a central line, you should first ________________.
place the patient in a left-lateral decubitus, Trendelenburg position (so that the bubble won’t travel to the brain)
According to PreTest, what is the treatment algorithm for anaphylaxis?
In a conscious patient:
1) Epinephrine (injected or inhaled)
2) Antihistamines
In an unconscious patient or someone with refractory hypotension:
1) Intubate
2) Epinephrine (injected)
I’ve read intubate first in other areas.
List the diagnostic criteria for immediate hemolytic transfusion reaction.
- Positive Coombs test
- Myoglobinuria
- Haptoglobin less than 50
What lab test may be an even better indicator of nutritional status than albumin?
Prealbumin
It has a shorter half-life and thus can detect acute nutritional shortages.
Explain respiratory quotient.
RQ is the ratio of CO2 production to O2 intake. It is an indicator of nutritional status in relation to ventilation status.
A ratio of 0.75 to 0.85 is ideal. A ratio of 1 indicates a high carbohydrate diet that may make weaning from ventilation difficult.
A patient has minor bleeding from a tracheostomy placed a couple days prior. What could this be and how should you manage it?
A tracheo-innominate artery fistula (called a sentinel bleed)
Because of the seriousness of this condition, examination in the OR with a bronchoscope is the safest option.
A patient with severe von Willebrand is having elective surgery. What should you give them beforehand?
Cryoprecipitate
A patient has obvious gastric contents in their pharyngeal area after an MVC. How should you manage this?
Bronchoscopy for removal of particulate matter
What is the diagnostic finding of ventilator-associated pneumonia?
> 10,000 CFUs/mL in bronchoalveolar lavage
How do you immediately treat malignant hyperthermia?
- Stop the operation
- Stop the anesthesia
- Hyperventilate with 100% O2
- Treat with IV dantrolene
List some things that increase and decrease CVP.
Increase:
- PPV
- Pneumothorax with mediastinal compression
- Vasoconstricting agents (phenylephrine)
- PE
Decrease:
- Hypovolemia
- Sepsis
- Anaphylaxis
- Neurogenic shock
Aortic angiography can result in what pathology that presents with eosinophilia, acute renal failure, and elevated ESR?
Cholesterol embolism to the renal arteries
After a surgery, a patient with a recent complex medical history develops nausea, vomiting, orthostatic hypotension, and fever. What endocrine problem might this be?
Adrenal insufficiency
Those who are sick already can sometimes develop adrenal insufficiency with the stress of surgery.
Signs of necrotizing wounds –enlarging erythema, blistering drainage –warrant ___________.
wide debridement
How can CVP help direct your efforts at diagnosing and correcting hypotension?
CVP will be low in hypovolemic states and normal in vasoplegiac states (like sepsis, anaphylaxis), so if the CVP is low you bolus fluids and if it is normal go for norepinephrine.
What kind of catheter would you want in a patient getting inotropic agents for cardiogenic shock?
A pulmonary heart catheter
The big question is “does this patient’s heart need inotropes?” You can answer that with a pulmonary catheter by titrating down the inotropes and seeing if the RV is able to pump on its own.
What does thrombin time measure?
Fibrinogen quality/quantity
An active thrombin is added to a pool of patient’s plasma. The rate-limiting factor is fibrinogen.
