Positioning&Thermal Regulation - Dr. Reed's Final 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.

A: Claw Hand - Bent 4th and 5th digits. Sensory deficit in 4th and 5th digit.

Question 4

What can impede venous return?

Answer 4

High PEEP
Positive Pressure Ventilation
Increased Intrathoracic Pressure
Systemic Vasodilation - Blood pooling in dependent areas
Neuromuscular Blocking Agents - normal muscle tone impaired

Question 5

What sort of things can alter patients’ normal compensatory mechanisms?

Answer 5

Anesthetic medications result in myocardial depression and vasodilation. NMBs decrease muscle tone, which can also cause blood pooling in dependent areas. GA blunts compensatory mechanisms to increase heart rate and SVR.

Question 6

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

Answer 6

Preload problem, which decreases stroke volume and decrease cardiac output

Question 7

Most commonly injured nerve in the supine position

Answer 7

Ulnar Nerve and Brachial Plexus

Question 8

Patients at high risk for postoperative vision loss are those in which positions

Answer 8

Lengthy procedures in the prone or steep Trendelenburg position (Per Dr. Reed - sitting position as well from hypotension optic ischemia)

Question 9

Most commonly injured nerve in the prone position

Answer 9

Optic Nerve or Spinal Cord

Question 10

Most commonly injured nerve in the lithotomy position

Answer 10

Common Peroneal Nerve (common fibular nerve)

Question 11

Most commonly injured nerve in the lateral decubitus position

Answer 11

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

Question 12

What position has the highest risk for Venous Air Embolism?

Answer 12

Sitting position

Question 13

You’re seeing a patient post-op with a chief complaint about their hand(s); , along with the common etiology if it was the Median Nerve what symptoms would be present

Answer 13

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 14

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 14

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

Question 15

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 15

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

Complaint: Wrist drop (can’t dorsal flex), inability to extend metacarpal joints, weakness of abduction of the thumb, index, and middle finger.

Question 16

A patient has a problem with making a fist. What nerve and etiology has occurred?

Answer 16

Median Nerve. Hand of Benediction(index and middle) or Ape Hand (thumb)
Can’t make a fist.

Question 17

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

Answer 17

Within the first hour

Question 18

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

Answer 18

Radiation

Question 19

Describe conduction heat loss

Answer 19

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

Question 20

Describe convection heat loss

Answer 20

Heat loss by cool air passing a warmer surface

Question 21

Describe radiation heat loss

Answer 21

Heat, like body heat, escapes into the cooler environment

Question 22

Describe heat loss via redistribution

Answer 22

Redistribution of cold blood to the central compartment

Question 23

Shoulder Operation in the sitting position. What are some of the risks associated with that position?

Answer 23

1. Optic Nerve ischemia. After load drops after induction. Going from supine to sitting forces blood away from the head/eyes, causing ischemia. (Dr. Reed: Likes SBP>105 and MAP= 70 or more)
2. Air embolus due to an open venous sinus above the heart. As the ventricles open and the atria empty, we create negative pressure, which can entrain air.

Question 24

The patient presents with foot drop; what nerve is injured?

Answer 24

The common peroneal nerve.

Question 25

What are the risks associated with intraoperative hypothermia?

Answer 25

Increased oxygen consumption through shivering
Increased cardiovascular incidents and MI
Interference with coagulation (impairing platelet function, slowing clot formation, slowing coagulation enzyme activity, and enhancing fibrinolysis)
Wound infection and delayed healing
Increased rate of sickling in SCD
Prolonged PACU stays