Positioning and nerve injury 2 Flashcards
Which nerve is MOST likely to be injured by an IV pole that presses against the dorsolateral aspect of the humerus?
a. median
b. radial
c. ulnar
d. axillary
b. radial
The radial nerve passes along the
spiral grove at the lateral aspect of the humerus (about three fingerbreadths above the lateral epicondyle)
Etiologies of radial nerve injury include
excessive cycling of the NIBG cuff
upper extremity tourniquet
external compression by an IV pole
sheets that are too tight (if the arms are tucked)
Radial nerve injury presents with
wrist drop
Long thoracic nerve injury presents with
a winged scapula
Suprascapular nerve injury presents with
dull shoulder pain
The long thoracic nerve arises from
C5-C7
The long thoracic nerve innervates the
serratus anterior muscle
Long thoracic nerve injury can occur from
lateral position
trauma
preexisting neuropathy (possibly d/t a virus)
The suprascapular nerve innervatest he
supraspinatus and infraspinatus muscles
The suprascapular nerve is anchored between
the cervical spine and the suprascapular notch
Etiology of suprascapular nerve injury is
the patient in the lateral decubitus position rolls onto their dependent arm
Properly stabilizing the patient and placing a roll distal to the axilla may reduce the risk of
suprascapular nerve injury
A patient developed foot drop following a vaginal hysterectomy. She was positioned in candy cane stirrups. which nerve was injured?
a. common peroneal
b. obturator
c. saphenous
d. femoral
a. common peroneal
The etiology of obturator injury is
flexion of the thigh towards the groin
excessive traction during abdominal surgery
forceps delivery
Obturator injury presents with
an inability to ADDuct the leg
Etiology of femoral injury is
excessive traction during lower abdominal surgery
Femoral injury presents with
impaired knee extension and hip flexion as well as reduced sensation over the anterior thigh and anteromedial aspect of the leg
Saphenous injury etiology is
external pressure applied to the medial aspect of the leg
Saphenous injury presents with
reduced sensation over the anteromedial aspect of the leg (just like femoral n. injury)
Etiology of common peroneal injury
external pressure at the level of the fibular head (common in the lithotomy position)
Common peroneal nerve injury presents as
foot drop and the inability to ever the foot
Etiology of sciatic injury is
excessive hip flexion and external rotation of the legs in the lithotomy position
sitting with straight legs
Patients with sciatic injury present with
foot drop
Etiology of pudendal injury is
the nerve is compressed against a perineal post on an orthopedic fracture table
Patients with pudendal injury present with
loss of perineal sensation
Leaving the patient’s legs crossed during surgery increases the risk of
sural nerve injury in the top leg and superficial peroneal injury in the bottom leg
Prevention of obturator nerve injury includes
minimizing hip flexion
Prevention of femoral injury includes
the surgical team should avoid excessive traction during lower abdominal surgery
Prevention of saphenous nerve injury includes
placing padding between leg and stirrup
Prevention of common peroneal injury includes
placing padding between the leg and stirrup
pad under the fibular head
knees should be flexed with minimal rotation
Prevention of sciatic injury includes
ample padding under buttocks
avoid excessive external rotation of the hips
flex table at the knees
Prevention of pudendal injury includes
adequate padding between the perineal post and the patient
Which complications are MOST commonly associated with the sitting position? (select 2)
a. tracheobronchial compression
b. midcervical tetraplegia
c. lower extremity compartment syndrome
d. paradoxical air embolism
b. midcervical tetraplegia
d. paradoxical air embolism
Compartment syndrome is most commonly seen in the
lithotomy position
Compartment syndrome can progress to
rhabdomyolysis or reperfusion injury
___________ is the treatment for compartment syndrome
Fasciotomy
This position is most commonly associated with VAE
the sitting position
VAE can occur in any position that produces
a pressure gradient between the atmosphere and the veins at the surgical site
Midcervical tetraplegia is associated with
hyperflexion of the neck (chin to chest)
Midcervical tetraplegia occurs in the __________ position and can also occur postoperatively in patients who have undergone ___________
sitting; tracheal resection
When compared to the Wilson frame and chest rolls, the ______________ is the best option to preserve normal pulmonary mechanics in prone patients (compliance is better and PIP is lower).
Jackson table
The _________ position provides optimal V/Q matching which explains its use for ARDS patients
prone
In the patient with a mediastinal mass, there are three things that worse tracheobronchial compression (i.e. airway collapse):
supine position
induction of general anesthesia
loss of spontaneous ventilation
When anesthetizing the patient with an anterior mediastinal mass, you should
preserve spontaneous ventilation and use a reinforced endotracheal tube
If the airway collapses in the patient with a mediastinal mass,
repositioning the patient laterally or prone may restore airway patency
Risk factors for lower extremity compartment syndrome include
surgical time >2-3 hours
Increased BMI
decreased tissue oxygenation (hypotension)
What is a venous air embolism?
VAE–> right heart–> pulmonary vasculature–> increased dead space and increased RV workload
What is a paradoxical air embolism?
right heart–> patent foramen ovale–> left heart–> systemic circulation–> stroke
In the supine position, ______________ of the lumbar spine can cause paraplegia
extreme hyperextension
Risk factors for paraplegia include
maximal retroflexion of the OR table
raising the kidney rest to its highest position
placing large rolls under the patient’s lumbar spine
When positioning the patient for surgery, you should be able to place __________________ in-between the chin and the chest
at least 2 fingers to prevent midcervical tetraplegia
The tumors likely to occur in the anterior mediastinum include
the four T’s
1. thymoma
2. teratoma
3. thyroid
4. terrible lympoma
A tumor of the anterior mediastinum can compress three vital structures:
tracheobronchial tree
pulmonary artery
superior vena cava
What action can help improve comfort in a supine patient with a history of back pain?
placing a small pad under the lumbar spine to preserve lordosis
