NAGELHOUT CH 40 EXAMPREP VERIFIED
QUESTIONS AND SOLUTIONS COMPLETE
LEARNING PACKAGE
●● According to the ASA closed claims project, what is the most
common nerve injury?
Answer: Ulnar 28%
Brachial Plexus 20%
●● What positions have minimal effects on lung capacities?
Answer: Sitting- normal FVC and FRC
Prone- when abdomen hangs free, increased FRC
●● How may you mitigate hypotension caused by position change?
Answer: - Slow assumption of surgical position
- Nitrous narcotic technique or 0.5 MAC or gradually attaining deeper
level of anesthesia
- Volume replacement used judiciously
- Trendelenburg (controversial)- increase venous return and MAP,
hypovolemia can be unrecognized in lithotomy and tburg because MAP
can appear normal
, ●● What are the 3 primary mechanisms of nerve injuries?
Answer: Transection- surgical maneuver or trauma
Compression- nerve forced against a bony prominence or hard surface
such as armboard or operative table
Stretch- with sciatic or brachial plexus, injury or elongation may cause
conduction changes, axonal disruption, or interruption of nerve vascular
supply
●● What are factors that contribute to nerve injuries? (4)
Answer: 1) Positioning devices
2) Length of procedure- > 4 hrs associated with POVL, nerve injuries,
compartment syndrome
3) Anesthetic technique- MRs contribute to stretch injury, hypotensive
techniques, neuraxial nerve blocks
4) Patient related factors- gender, extreme age, obesity, pre-existing
medical conditions
●● What intraop occurrences contribute to peripheral nerve injury?
Answer: Hypovolemia
Hypotension
Induced hypothermia
Hypoxia
QUESTIONS AND SOLUTIONS COMPLETE
LEARNING PACKAGE
●● According to the ASA closed claims project, what is the most
common nerve injury?
Answer: Ulnar 28%
Brachial Plexus 20%
●● What positions have minimal effects on lung capacities?
Answer: Sitting- normal FVC and FRC
Prone- when abdomen hangs free, increased FRC
●● How may you mitigate hypotension caused by position change?
Answer: - Slow assumption of surgical position
- Nitrous narcotic technique or 0.5 MAC or gradually attaining deeper
level of anesthesia
- Volume replacement used judiciously
- Trendelenburg (controversial)- increase venous return and MAP,
hypovolemia can be unrecognized in lithotomy and tburg because MAP
can appear normal
, ●● What are the 3 primary mechanisms of nerve injuries?
Answer: Transection- surgical maneuver or trauma
Compression- nerve forced against a bony prominence or hard surface
such as armboard or operative table
Stretch- with sciatic or brachial plexus, injury or elongation may cause
conduction changes, axonal disruption, or interruption of nerve vascular
supply
●● What are factors that contribute to nerve injuries? (4)
Answer: 1) Positioning devices
2) Length of procedure- > 4 hrs associated with POVL, nerve injuries,
compartment syndrome
3) Anesthetic technique- MRs contribute to stretch injury, hypotensive
techniques, neuraxial nerve blocks
4) Patient related factors- gender, extreme age, obesity, pre-existing
medical conditions
●● What intraop occurrences contribute to peripheral nerve injury?
Answer: Hypovolemia
Hypotension
Induced hypothermia
Hypoxia
