Random anesthesia/emergency scenerio facts

Question 1

How does a BP cuff work?

Answer 1

Oscillometric method. NIBP cuff inflated until oscillation in the blood pressure is no longer measured (systolic BP). As the cuff is deflated the point of maximum oscillation sis the MAP. Algorithms are used to calculate the diastolic pressure (which is typically estimated higher than true diastolic pressure).

Question 2

How does a pulse oximeter work?

Answer 2

Measures oxygen saturation in the blood by detecting differences in light absorption between oxygenated and deoxygenated hemoglobin. This difference in the ratio of absorption is displayed as oxygen saturation in the blood. This does not tell you about oxygen content or adequacy of oxygen delivery to tissues. The oxygen hemoglobin dissociation curve helps estimate the partial oxygen tension. Below 90% oxygen saturation, the PaO2 declines precipitously

Question 3

What is the maximum oxygen delivery (L/minute and FiO2) via nasal canula?

Answer 3

6 L/minute, 44% FiO2

Question 4

What is the minimum oxygen delivery (L/minute) via simple face mask, what is the FiO2 achievable by simple face mask?

Answer 4

Need to give at least 5-6 L/minute to prevent rebreathing. At 7-8 L/minute can deliver 60% FiO2.

Question 5

What is the minimum oxygen delivery (L/minute) via partial rebreather, what is the FiO2 achievable by partial rebreather?

Answer 5

Minimum rate of 8L/min
Flow rate of 15 L/minute will deliver FiO2 of 90%

Question 6

What is the FiO2 achievable by an ambu-bag (self-inflating resuscitation bag)?

Answer 6

Flow rate of 10-15 L/minute can deliver FiO2 of 100%

Question 7

What are predictors of a difficult intubation?

Answer 7

-High Mallampti score
-Thyromental distance <6 cm
-Limited neck extension
-Obesity

Question 8

What are predictors of difficult ventilation?

Answer 8

-Obesity
-Prescence of a beard
-Age >55
-Edentulous
-History of snoring

Question 9

Describe the ASA classes.

Answer 9

Class 1: Normal, healthy patient
Class 2: Mild systemic disease resulting in no functional limitations (controlled HTN, chronic bronchitis, extremes of age, smoker)
Class 3: Severe systemic disease resulting in functional limitations (diabetes, previous MI, pulmonary disease limiting activity)
Class 4: Severe systemic disease that is a constant threat to life (CHF, unstable angina, advanced pulmonary, renal or hepatic dysfunction)
Class 5: Moribund patient who is not expected to survive without operation or intervention
Class 6: Documented brain death (organ donation)