Apex- Positioning Flashcards
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Sitting and flexed lateral
(positions that decrease preload)
Attenuate = enhance or reduce
REDUCE
- this word will be the death of me so im just gonna start throwing it in randomly
Trendelenberg and lithotomy shift the frank-starling curve to the (left/right)
right- increased preload
Prone- frank starling curve shifts to left or right
left - blood shifts away from central circulation/venous pooling
hemodynamic effect of flexed lateral position
- shifts franks curve to the left
- decreased preload
- venous pooling in legs
The risk of cerebral hypoperfusion is increased when the brain is higher than the heart; where should you transduce your aline
at the external auditory meatus
Compared to the awake, spontaneously breathing patient, the anesthetized patient who is spontaneously breathing as an:
increase/decrease in the following:
tidal volume
FRC
closing volume
decreased: Vt & FRC
increased closing volume
Why does trendlendberg increase the risk of endobronchial intubation
bc all the abdominal contents shift cephalad which pushes the diaphragm towards the ETT
T/F- shoulder brances increase the risk of brachial plexus injury
true
2 types of injury that can occur to the brachial plexus
1. stretch injury
- brachial plexus is fixed at the cervical vertebrae and the axillary fascia.
- risk of stretch injury is highest when the arms are ABducted > 90 degrees and the head is rotated to the other side
2. compression injury
- compression as it passes between the clavical and first rib (shoulder braces)
- or by external force (improperly placed ax roll)
Where is the brachial plexus anatomically fixed (2 locations)
cerbical vertebrae and axillary fascia
when is the risk of brachial plexus stretch injury the highest?
when arms ar abducted > 90 degrees and head is rotated to the other side
shoulder braces cause what kind of nerve injury
brachial plexus (compression)
Prone position considerations that should be looked at to decrease risk of brachial plexus injury (2)
- don’t let shoulders sag forward
- arms shouldn’t be extended over the head (keep shoulders and elbows at 90 degrees or less)
When interviewing a patient preop who will be in a prone position, what is a good assessment to evaluate for potential thoracic outlet syndrome
ask them to clasp their hands behind their head; if + pain, tuck the arms
in lateral decub; the downside thigh and knee are flexed; why should there be padding between the weight of the leg and the table? what nerve is compromised?
common peroneal nerve
In lateral decub, a retaining strap should NOT be directly over what
the head of the femur
- it should be across the hip and fixed under the OR table
- between the ilac crest and head of femur
Pt is unable to ubduct his fifth digit aafter a prolonged stay in the ICU. Which nerve sustained an injury?
A. Ulnar
B. Median
C. Radial
D. Long throacic
A. Ulnar
What is the most commonly injured peripheral nerve?
Ulnar nerve
Ulnar nerve injury can present in what 3 ways
- impaired sensation to the 4th and 5th digits
- inability to ABduct or oppose the pinky finger
- claw hand (chronic injury/muscular atrophy)
5 risk factors for ulnar injury
- poor padding/positioning
- males (esp > 50yo)
- pre-exisiting ulnar neuropathy
- extremes of body habitus (very thin or obese)
- prolonged hospitalization/bedrest
claw hand signifies what injury
chronic ulnar (muscular atrophy)
What nerve injury can result from external compression from an excessively tight arm strap on the forearm
Ulnar
T/F- elbow extension increases risk for ulnar nerve injury
false- flexion
Most cases of ulnar neuropathy don’t present until > ____ hrs after surgery
24hrs
Hand positioning when arms are abducted or tucked has to deal with protecting the patient from which kind of nerve injury
ulnar
What position(s) can the hands be in if the arms are abducted
what should be avoided?
yes: supinated or thumbs up
NO PALMS DOWN
What way should the hands face when arms are tucked at side
with thumbs up
(supinate and pronated hans = bad)
what nerve injury
ulnar
T/F- sensory deficits are more common and less serious and tend to resolve on their own
True- within 5 days or less
*get neuro consult if perisists more than 5 days
Which nerve is MOST likely to be injured following a traumatic IV insertion in the antecubital space?
A. Ulnar
B. Radial
C. Median
D. Axillary
C. Median
What nerve injury is associated with decreased sensation over the palmar surface of the thumb, index finger, middle finger, and lateral aspect of the ring finger
median nerve
What nerve injury presents as an inability to oppose the thumb
median nerve
What nerve is affected with carpal tunnel syndrome?
Median nerve
(only nerve that passes through the carpal tunnel)
What nerve is injured with elbow hyperextension
median nerve
T/F- excessive BP cuff cycling can cause median nerve injury
False - RADIAL
Which nerve is MOST likley to be injured by an IV pole that presses agaisnt the dorsolateral aspect of the humerous?
A. Median
B. Radial
C. Ulnar
D. Axillary
Radial
Bone in the upper arm
Humerous
(just incase i forget- LOL)
Bone in the lower arm
Radius
(just incase I forget LOL)
What nerve injury can present from a upper extremity tourniquet?
Radial
What nerve injury can present from sheets being too tight when arms are tucked?
Radial
Which nerve injury presents with wrist drop?
Radial nerve injury
which nerve injury presents as a winged scapula
long throacic nerve injury
which nerve injury presents with dull shoulder pain
suprascapular nerve injury
What nerve passes along the spiral groove at the lateral aspect of the humerous (about 3 fingerbredths above the lateral epicondyle).
The radial nerve
What type of nerve injury
Radial nerve injury (wrist drop)
-IV pole, BP cuff, tourniquette, sheets too tight when tucked
What nerve injury is this from
Long Thoracic
(SALT) - Serratus Anterior Long Thoracic
3 eitilogies of long thoracic nerve injury
lateral position, trauma, pre-existing neuropathy
The long throacic nerve arises from _______ and innervates the ______
C5-C7
serratus anterior muscle
- (SALT)
- serratus anterious/long thoracic
- dorsal protrusion of the scapula/winged scapula
What nerve is anchored between the C-spine and the suprascapular notch?
Suprascapular nerve
What injury presents from ventral circumduction of the depedent shoulder in the lateral decub position
-what can diminish this risk?
stretch injury to the suprascapular nerve
- pt rolls onto the depedent arm
- ax roll can diminish this risk
A Patient develped foot drop following a vaginal hysterectomy. She was positioned in candycane stirrups. Which nerve was injured?
A. Common peroneal
B. Obturator
C. Saphenous
D. Femoral
A. common peroneal
which nerve injury presents with the inability to ADDuct the leg
obturator
Flexion of the high towards the groin, excessive traction during abdominal surgery, and forceps delivery can all injury what nerve
obturator
what kind of nerve injury can present from excessive traction during lower abdominal surgery?
How would it present (3)
Femoral
- impaired knee extension
- impaired hip flexion
- decreased sensation over the anteriomedial aspect of leg
Which two nerve injurys can resutl in reduced sensation over the anteromedial aspect of the leg?
Femoral and Saphenous
what nerve injury can present from external pressure applied to the medial aspect of the leg
saphenous injury
What is the nerve injury common in lithotomy position? (3)
-
Common peroneal nerve injury
- external pressure at the FIBULAR head
- foot drop, cant evert foot, cant extend toes dorsally
- Sciatic
- excessive HIP FLEXION and extenral rotation
- foot drop
- Saphenous
- extenral pressure at teh MEDIAL/TIBIAL aspect
- decreased sensation over the anteromedial aspect of the leg
What nerve injury results from external pressure at the level of the fibular head?
Common peroneal injury (lithotomy)
Pt presents with foot drop, what nerve was injured (2 possiblities - how to differentiate)
1. Common Peroneal
- Foot drop + inability to evert the foot
2. Sciatic
- Foot drop
What nerve injury presents if the nerve is compressed agaisnt a perineal post on an orthopedic fracture table?
-Pudendal injury
(loss of penile sensation)
which nerve injury presents wtih loss of penile sensation
pudendal injury
Leaving the patient with leg’s crossed during surgery increases the risk of _______ nerve injury in the top leg and __________injury in the bottom leg
sural nerve injury - top leg
peroneal injury - bottom leg
- foot drop
- can’t evert foot
- external pressure on the fibular head
T/F- the saphenous vein resides near the tibia
true
identify these structures
Top bone = femor
small skinny bone = fibula (pointing to fibular head)
common peronal nerve
bigger lower bone = tibia
What nerve injury can occur from sitting with legs straight
sciatic
(foot drop)
-pad butt, avoid external rotation of hips, flex table at knees
Nerve injury that results with decreased sensation over the MEDIAL aspect of the thigh
obturator
(femoral = anterior thigh)
Which complications are MOST commonly seen with the sitting position? (2)
- Tracehobronchial compression
- midcervical tetraplegia
- lower extremity compartment syndrome
- paradoxical air embolism
-midcervical tetraplegia & paradoxical air embolism
What is midcervical tetraplegia caused by?
-what position is this most concerning in
hyperflexion of the neck (chin to chest)
-sitting
(but can also occur in patients who underwent tracheal resection (have to have chin to chest for a while until it heals )
Compartment syndrome is most commonly seen in what position?
What’s the treatment
lithotomy
-fasciotomy
Which is better to preserve normal pulmonary mechanics:
Wilson frame and chest rolls or the jackson table
jackson stable
Why do we use the prone position for patients with ARDS
it provides optimal V/Q matching
-maybe one day ill fucking understand this
In the patient with a mediastinal mass, what 3 things can worsen tracheobronchial compression (airway collapse):
- supine position
- induction of general anesthesia
- loss of spontaneous ventilation/need for positive pressure ventilation)
When anesthetizing the patient with an anterior medastinal mass, what 2 things should you do?
What do you do if the airway collapses?
- maintain spontaneous respirations and use a reinforced ETT
- if you lose the airway, position laterally or prone
Who is at increased risk for LE comparment syndrome while in lithotomy?
- surgical time > 2-3 horus
- increased BMI
- decreased tissue oxygenation (hypotension)
In what instances would a venous air emboli cause RV strain vs stroke?
RV strain if normal vasculature (gets lodged in pulm vasculature > increased dead space > increased RV strain)
Stroke if +PFO (VAE > PFO > Left > circ > brain)
When in the sitting position, you shouldbe able to place at least ____ fingers in-between the chin and chest - why?
2 - to avoid hyperflexion of the neck which could lead to midcervical tetraplegia
When you place the patient in prone position, your primary objective is to minimize pressure on what 2 things and why
Abodmen and vena cava
- to improve pulmonary mechanics
- improve venous return
- decrease venous pressure
What action can help improve the comfort in a supine patient with a hx of back pain?
placing a small pad under the lumbar spine to preserve lordosis
A patient who is unable to ADDuct her right leg following a difficult forcepts delivery MOST likely sufferered an injury to which nerve?
- Sciatic
- Obturator
- Femoral
- Lateral femoral cutaenous
-Obturator
Which surgical position increases the risk of suprascapular nerve injury?
- Lateral decub
- Trendlenburg
- Reverse T
- Prone
Lateral decub
(ventral circumduction of the depedent shoulder)
