Positioning&Thermal Regulation - Dr. Reed's Review

Question 1

Arms should be less than _____ degrees or tucked in the supine position.

Answer 1

90 degrees

Question 2

My arm is abducted while lying supine; what nerve is most commonly injured because of pressure in the OR?

Answer 2

Ulnar Nerve

Question 3

If the Ulnar Nerve is injured, how will it manifest symptomatically?

Answer 3

Claw Hand
Inability to abduct or oppose the 4th and 5th digit. Diminished sensation of the medial side of fingers. Claw-like appearance over time.

Question 4

There are a couple of things that can impair/alter normal compensatory mechanisms. What can impede venous return?

Answer 4

High PEEP
Positive Pressure Ventilation
Increased Intrathoracic Pressure
Systemic Vasodilation - via General Anesthetic (compensatory mechanisms, like HR increase, are blunted)
Blood pooling in dependent areas
Neuromuscular Blocking Agents - normal muscle tone impaired

Question 5

When we decrease venous return, what kind of problem is that?

Answer 5

Preload problem, which decreases stroke volume and decrease in cardiac output

Question 6

Most commonly injured nerve in the supine position

Answer 6

Ulnar Nerve and Brachial Plexus

Question 7

Most commonly injured nerve in the prone position

Answer 7

Optic Nerve or Spinal Cord

Question 8

Most commonly injured nerve in the lithotomy position

Answer 8

Common Peroneal Nerve (common fibular nerve)

Question 9

Most commonly injured nerve in the lateral decubitus position

Answer 9

Brachial Plexus!, Suprascapular, Long Thoracic, Peroneal and Radial

Question 10

What position has the highest risk for Venous Air Embolism?

Answer 10

Sitting position

Question 11

You’re seeing a patient post-op with a chief complaint about their hand(s); what nerve has been injured, along with the common etiology if it was the Median Nerve

Answer 11

Etiology: Extension of elbow beyond the normal range. IV placement error/damage

Chief Complaint: Hand of Benediction, Inability to make a fist. Decreased sensation of the thumb, index, and middle finger plamer side

Question 12

You’re seeing a patient post-op with a chief complaint about their hand(s); what nerve has been injured, along with the common etiology if it was the Ulnar Nerve

Answer 12

Ulnar nerve compressed against posterior aspect of medial epicondyle of humerus.

Question 13

You’re seeing a patient post-op with a chief complaint about their hand(s); what nerve has been injured, along with the common etiology if it was the Radial Nerve

Answer 13

Etiology: Arm pressed against a vertical position or retractor post or pole. Intraop use of tourniquets. Frequent blood pressure cycling.

Complaint: Wrist drop, inability to extend metacarpal joints, weakness of abduction of the thumb, index, and middle finger.

Question 14

A patient has a problem with dorsal flexion or tunability to make a fist. What nerve and etiology has occurred?

Answer 14

Median Nerve. Hand of Benediction or Ape Hand

Question 15

When does most of the patient’s heat loss occur in the OR?

Answer 15

Within the first hour

Question 16

By what mechanism is most heat loss occurring during that first hour?

Answer 16

Radiation

Question 17

Describe conduction heat loss

Answer 17

Heat loss by physical contact. A warmer object comes into contact with a cooler object.

Question 18

Describe convection heat loss

Answer 18

Heat loss by cool air passing a warmer surface

Question 19

Describe radiation heat loss

Answer 19

Heat, like body heat, escapes into the cooler environment

Question 20

Describe heat loss via redistribution

Answer 20

Redistribution of cold blood to the central compartment