Exam 1: Respiratory

Question 1

Best indicators of postoperative pulmonary complications for patients undergoing pulmonary surgery:

Answer 1

DLCO < 40%
FEV1 < 40%
VO2 max < 15 mL/kg/min

Question 2

Test for lung parenchymal function (hint: gas exchange)

Answer 2

DLCO

Question 3

test for respiratory mechanics (hint: airflow)

Answer 3

FEV1

Question 4

test for cardiopulmonary reserve and normal values

Answer 4

VO2 max

normal male: ~35-40 mL/kg/min
normal female: ~27-31 mL/kg/min

Question 5

when is split lung V/Q function testing indicated?

Answer 5

when DLCO, FEV1, or VO2 max are less than normal values. suggests increased risk postop pulmonary complications.

Question 6

how do you assess cardiopulmonary reserve is VO2 max is not available?

Answer 6

ask the patient if s/he can climb 2 flights of steps (if no, pt is at risk)

Question 7

why is a left-sided DLT typically preferred?

Answer 7

less risk of occluding the upper lobe

Question 8

indications for a right-sided DLT (2)

Answer 8

1. left main bronchus has distorted anatomy (i.e. tumor, TAA)
2. surgical procedures i.e. left pneumonectomy, left lung transplant, or left sleeve resection

Question 9

bronchial cuff:
- what is it (volume + pressure)
- how much volume

Answer 9

• low-volume (1-2 mL), high-pressure cuff
• overinflation increases risk of mucosal injury
• keep DEFLATED when not needed

Question 10

how much volume is inflated into the tracheal cuff?

Answer 10

HIGH-volume, LOW-pressure cuff
5-10 mL

Question 11

DLT size for females:

Answer 11

< 160 cm = 35 Fr
> 160 cm = 37 Fr

Question 12

DLT size for males:

Answer 12

< 170 cm = 39 Fr
> 170 cm = 41 Fr

Question 13

DLT insertion depth for FM

Answer 13

~27 cm

Question 14

DLT insertion depth for M:

Answer 14

~29 cm

Question 15

DLT for children younger than 8

Answer 15

no!
bronchial blocker or SLT advanced into mainstem bronchus

Question 16

during anesthesia in the lateral decubitus position, which lung is better ventilated?

Answer 16

non-dependent (operative…UP) lung

Question 17

during anesthesia in the lateral decubitus position, which lung is better perfused?

Answer 17

dependent lung (DOWN lung)

Question 18

what increases the shunt fraction and is a significant source of hypoxemia during thoracic surgery?

Answer 18

mixing of blood from the non-dependent (non-ventilated) and dependent (ventilated) lung

Question 19

what are suggested settings for OLV for FiO2, Vt, RR, and PEEP

Answer 19

FiO2: 100%
Vt: 6-8 mL/kg IBW
RR: 12-15 bpm
PEEP: 5-10 cm H2O

Question 20

hypoxemia during OLV, after verifying the delivery of 100% O2, what should the CRNA do FIRST?

Answer 20

check the position of the tube/bronchial blocker via fiberoptic bronchoscopy

Question 21

what could be some physiologic causes of hypoxemia during OLV?

Answer 21

reduced cardiac output
bronchospasm
mucus plug
PTX of the dependent lung

Question 22

hypoxemia during OLV. which lung CPAP and which lung PEEP?

Answer 22

CPAP = non-dependent lung
PEEP = dependent lung