positioning and nerve injury Flashcards
what positions cause frank starling relationship to go from point A to point B?
sitting
flexed lateral
venous pressure increases
hydrostatic pressure, intracranial HTN
interventions that promote CV stability
slow repositioning
lighter plane of anesthesia
IV hydration
consequences of trendelenburg positioning include
diaphragm moves cephalad
FRC reduced
p. compliance is decreased
risk of endobronchial intubation is increased
dependent and non dependent lung/region for the following positions:
sitting
supine
left lateral
right lateral
what can create edema formation
prone and trendelenburg
sitting (neck flexion and impaired drainage)
equipment (OPA, esophageal temp probe) impairs lymphatic drainage
best position to protect brachial plexus during radical prostatectomy
arms tucked at sides and non sliding mattress
do shoulder braces decrease risk of brachial plexus injury
no they increase the risk
if they HAVE to be used, they need to be placed at the distal end of each clavicle (over the acromion)
risk of brachial plexus stretch injury is highest when
arms are abducted greater than 90 degrees and head is rotated to the other side
when does compression injury of brachial plexus usually occur
when brachial plexus is compressed as it passes between clavicle and first rib (shoulder braces) or by an external force (improperly placed axillary roll)
supine position related considerations
arm abduction >90 degrees stretches brachial plexus around head of humerus
neck rotation stretches brachial plexus on contralateral side
excessive sternal retraction during cardiac surgery (median sternotomy) can compress brachial plexus under first rib
trendelenburg position related considerations
use non sliding mattress
a bean bag that envelopes the shoulders can also cause compression injury
prone position related considerations
shoulders should not be allowed to sag forward
arms should not be extended over the head
assess for thoracic outlet syndrome (in preop, ask patient to clasp hands over head. if she complains of pain, tuck arms)
lateral decubitus related position considerations
chest support (axillary roll) is placed distal (caudad) to axilla
maintain neutral neck alignment with pillow or head rest
common peroneal nerve should be padded to prevent injury from weight of leg against table
upside thigh and leg are extended and separated from lower leg with pillows
minimize risk of a circumduction of down side shoulder to minimize risk of injuring supra scapular nerve (aka dont let patient roll forward)
retaining strap placed across hip and fixed to under belly of OR table. should be placed between iliac crest and head of femur
a patient is unable to abduct his 5th finger after a prolonged stay in the ICU. which nerve sustained an injury?
ulnar n
presentation of ulnar n injury may include
impaired sensation of 4th/5th digits
inability to abduct or oppose pinky finger
chronic injury presents with claw hand (muscular atrophy)
most commonly injured peripheral nerve
ulnar n
anatomy of cubital tunnel
ulnar nerve emerges from cubital tunnel between humeral and ulnar heads of flexor carpi ulnaris
mechanism of ulnar nerve injury
external compression (excessively tight arm strap on forearm)
elbow flexion –> increased distance between medial epidondyle and olecranon, decreased cubital tunnel size, increased pressure on the ulnar n
risk factors that predispose patients to ulnar nerve injury includes
male (esp >50y)
preexisting ulnar neuropathy
extremes of body habitus
prolonged hospital stay/bedrest
cardiac surgery
most cases of ulnar neuropathy dont present until how long after surgery?
> 24h
best way to position forearm in supine position- are the following ok if the arm is abducted? at patients side?
what to do if a patient presents with postop nerve injury: sensory deficits
more common, less serious, tend to resolve on their own (5 days or less)
get a neurology consult if it lasts >5d or gets worse
prudent to consult with neurologist within first week of injury
what to do if a patient presents with postop nerve injury: motor deficits
less common, more serious, if demyelination occurs can take up too 4-6w to recover
-need PT, neurology consult, EMG and nerve conduction studies
where is the median nerve located in relation to surrounding veins
next to basilic and median veins in cubital fossa
causes of median nerve injury include
IV placed in AC space
carpal tunnel syndrome (median nerve is only nerve that passes through carpal tunnel)
elbow hyper extension
forced elbow during positioning after NMB has been administered
presentation of median nerve injury
reduced sensation over palmar surface of the thumb, index finger, middle finger, and lateral aspect of ring finger
unable to oppose thumb
chronic injury can lead to ape hand deformity