Pulmonary function testing

Question 1

This test refers to a standardized measurement of a patient’s airflow (spirometry), lung volumes, and diffusing capacity for inspired carbon monoxide (DLCO).

Answer 1

Pulmonary function test

Question 2

What is the goal of pulmonary function testing?

Answer 2

The primary goal of preoperative pulmonary function testing, also called spirometry, is to recognize patients at high or prohibitive risk for postoperative pulmonary complications.

Question 3

Is a test most accurate for determining FRC in patients with obstructive airway disease and applies Boyle’s law, which states that the volume of gas in a closed space varies inversely with the pressure to which it is subjected.

Answer 3

Plethysmography

Question 4

A condition that may cause an increasing DLCO.

Answer 4

Perforated tympanic membrane may cause an artifactually high DLCO by permitting an escape of CO by a nonpulmonary route.

Question 5

Is the concentration at one atmosphere that abolishes motor response to a painful stimulus (i.e., surgical incision) in 50% of patients. How much is needed to abolish the response in 99% of patients.

Answer 5

MAC

1.3 MAC

Question 6

Is the concentration required to block autonomic reflexes to nociceptive stimuli.

Answer 6

MAC-BAR

1.7-2 MAC

Question 7

Is the concentration required to block appropriate voluntary reflexes and measure perceptive awareness

Answer 7

MAC awake

0.3-0.5

Question 8

The highest MACs are found in?

Answer 8

Infants 6-12 months

Question 9

What factors decreases MAC? (7)

Answer 9

1) Hyponatremia
2) Opioids
3) Barbiturates
4) a2-blockers
5) Calcium channel blockers
6) Acute alcohol intoxication
7) Pregnancy

Question 10

Describes the distribution of a given agent at equilibrium between two substances at the same temperature, pressure, and volume.

Answer 10

Partition coefficient

Question 11

Describes the distribution of anesthetic between blood and gas at the same partial pressure.

Answer 11

Blood-to-gas coefficient

A higher blood-to-gas coefficient correlates with a greater concentration of anesthetic in blood (i.e., a higher solubility). Therefore a greater amount of anesthetic is taken into the blood, which acts as a reservoir for the agent, reducing the alveolar concentration and thus slowing the rate of induction.

Question 12

Two persons independently observed that an increasing oil-to-gas partition coefficient correlated with anesthetic potency.

Answer 12

Meyer and Overton

Question 13

Two persons found that an amphophilic solvent (octanol) correlated better with potency than lipophilicity and concluded that the anesthetic site must contain both polar and nonpolar sites.

Answer 13

Franks and Lieb

Question 14

Factors that increase alveolar anesthetic concentration speed onset (3)

Answer 14

1) Increasing concentration
2) High flow
3) Increasing minute ventilation

Question 15

Factors that decrease alveolar anesthetic concentration speed onset (4)

Answer 15

1) Increasing CO
2) Decreasing minute ventilation
3) High solubility
4) Low flow

Question 16

What is the second gas effect?

Answer 16

Because nitrous oxide is insoluble in blood, its rapid absorption from alveoli results in an abrupt rise in the
alveolar concentration of the accompanying volatile anesthetic.

Question 17

When nitrous oxide is discontinued abruptly, its rapid diffusion from the blood to the alveolus decreases the oxygen tension in the lung, leading to a brief period of
decreased oxygen concentration known as?

Answer 17

Diffusion hypoxia

Question 18

MAC is increased by (3)?

Answer 18

1) hyperthermia
2) chronic alcoholism
3) CNS stimulants (e.g., cocaine).

Question 19

Nice to know

Answer 19

Nitrous oxide toxicity is a rare but real threat in abusers, patients with vitamin B12 deficiencies, and possibly unborn fetuses because of impaired methionine synthesis and results in neurologic sequelae.

Question 20

Which anesthetic agent is most associated with cardiac dysrhythmias?

Answer 20

Halothane
Halothane has been shown to increase the sensitivity of the myocardium to epinephrine, resulting in premature ventricular contractions and tachydysrhythmias.

Compared with adults, children undergoing halothane anesthesia appear to be relatively resistant to this sensitizing effect, although halothane has been shown to have a cholinergic, vagally induced bradycardic effect in children.

Question 21

Fluoride-associated renal dysfunction has been linked to the use of?

Answer 21

Methoxyflurane

The fluoride produced by sevoflurane has not been implicated in renal dysfunction.

Question 22

This volatile anesthetic, much more than any other volatile anesthetic, has been associated with the production of carbon monoxide (CO).

Answer 22

Desflurane

Question 23

Are the stronger alkalis and result in greater CO production.

Answer 23

Potassium hydroxide (KOH)-coontaining absorbents