Flashcards in Positioning Deck (77)
What is the purpose of operative positioning?
Who is responsible for operative positioning?
the anesthesia provider
What should the CRNA document in regards to positioning for a case?
baseline ROM and function
frequency of checks
What are the height and weight limits for a standard OR table?
136 kg (~300lbs)
What are the 5 most common operative positions?
What are the advantages of the supine position?
access to airway
access to arms for IVs
less physiologic changes than the other positions
What is the benefit of placing a pillow under the head in the supine position?
avoids extension or flexion of the head
places the head/neck in sniffing position
doughnut pillow reduces alopecia (especially in neonates or the elderly)
no pressure on the eyes
How should arms be positioned in the supine position?
tucked - palm in, elbow padded, tuck draw sheet under patient torso
arm boards - secured to OR table, abducted <90 degrees, padded, safety strap on, hands supinated
How should the feet be positioned in supine position?
heels shouldn't hang over the bed
How should the spine be positioned in the supine position?
slight flexion behind the hips and knees
pillows under the knees
legs should not be crossed
What are the 5 mechanisms of nerve injury?
What are some modifiable factors that put you at risk for nerve injury?
What is the most common upper peripheral nerve injury?
How can injuries occur to the brachial plexus?
mostly stretch injuries
1. neck extension or head turned too much to the side
2. excessive abduction of the arms >90 degrees
3. arm/arm board falling off the table
What symptoms would show in a brachial plexus nerve injury?
electric shocks or a burning sensation down the arm
weak arm function
How does injury to the radial nerve occur?
compression of the radial nerve on the lateral aspect of the humerus against surgical retractors, ether screen, "step off", repeated BP inflation
Injury to the radial nerve will result in..
inability to flex the elbow
weakness in abduction of the thumb
How does an injury to the ulnar nerve occur?
compression between the olecranon of the ulna and medial epicondyle of the humerus
stretching with severe elbow flexion
What are the consequences of ulnar nerve injury?
claw hand -- inability to abduct or oppose 4th and 5th finger, weak grip on the ulnar side of hand
How can you reduce the risk of ulnar nerve injury?
pad arm boards
avoid overcompression by arm straps
place BP cuff proximal to the cubital fossa
avoid prolonged flexion of the elbow
What are the cardiovascular effects in the supine position?
initially increased venous return to the heart but there is a compensatory activation of baroreceptors that decreases HR and PVR
Under what circumstances might venous return be impeded in the supine position?
abdominal/thoracic masses, obesity, pregnancy, ascites
What ventilatory changes occur in the supine position?
FRC changes +/- 800 mL
may be compounded by muscle relaxants
can be overcome with PPV
What cerebral changes occur in the supine position?
minimal changes r/t autoregulation
What are the benefits of trendelenburg
may transiently treat hypotension
may improve surgical exposure
helps prevent air embolism
facilitates placement of central line insertion
Describe the placement of shoulder pads
should be padded and placed laterally... away from the neck and near the acromioclavicular joint
What are the cardiovascular changes associated with trendelenburg position?
reduces blood flow to the lower extremities
can cause compression of the heart
increases venous return to the heart
What ventilatory changes are associated with trendelenburg position?
displacement of abdominal contents will cause decreased lung compliance, PIP increases, decreased lung volumes, V:Q mismatch, ETT displaced to the R main bronchus, risk of aspiration, airway edema
What are the cerebral changes associated with trendelenburg position?
increased ICP and increased IOP r/t vascular congestion