Positioning And Nerve Injury

Question 1

How does trendelenburg and lithotomy affect blood circ?

Answer 1

Blood shifts towards central > increase venous return >shifts Frank starling curve to the right

**MAP stays the same or increases
**venous pressure increases > increased hydrostatic pressure > edema of face, eye, and airway

Question 2

What are some complications to Tberg and lithotomy?

Answer 2

Patients with poor cardiac fx may not tolerate shift

Mask hypovolemia

Question 3

How does sitting, flexed lateral and prone affect blood circ?

Answer 3

Away from central > venous pooling > decreased venous return > shifts patient to the left on Frank starling

**higher incidence of Hemodynamic instability (decreased SV, CO, and BP)

**risk of cerebral hypoperfusion

Question 4

Where should you zero the a-line in a patient in the sitting position?

Answer 4

Auditory meatus

Question 5

How does t-berg affect the pulmonary system?

Answer 5

Diaphragm moves cephalad
FRC is reduced
Pulmonary compliance is decreased
Risk of endobronchial intubation is increased

Question 6

How does the head up position (reverse t) affect the pulmonary system?

Answer 6

Diaphragm caudad
Increased pulmonary compliance
Decreased peak pressures
Increased total lung volume
Increased FRC

Question 7

What should you do if you are concerned about airway patency before extubation?

Answer 7

Perform a leak test
Visually inspect the larynx

Question 8

How should you position for a robotic assisted laparoscopic radical prostatectomy?

Answer 8

Arms ticked at side on a non-sliding mattress

Question 9

When is the risk for brachial plexus injury the highest?

Answer 9

When the arms are abducted > 90 degrees and the head is rotated to the other side

Question 10

Should you ever use shoulder braces?

Answer 10

No! They do more harm than good. A non-sliding mattress is the better option

Question 11

How do you assess for thoracic outlet syndrome? Especially in prone

Answer 11

Ask patient to clasp hands behind their head ~ if pain, tuck arms in prone position

Question 12

Where is a axillary roll placed?

Answer 12

Distal to the Axilla

Question 13

How are the legs positioned in laterus decubitus?

Answer 13

Downside though and knee are flexed; upside thigh and leg are extended and separated by pillow

Question 14

What is the most commonly injured peripheral nerve?

Answer 14

Ulnar nerve

Presentation:
> impaired sensation to 4th or 5th digit
> inability to ABDuct or oppose pinky finger
> chronic injury presents as CLAW hand

Question 15

What is claw hand?

Answer 15

Chronic ulnar nerve injury

Question 16

Wha rare some risk factors to ulnar nerve injury?

Answer 16

Male gender
Preexisting ulnar nerve injury
Extremes of body habitus
Prolonged hospital stay
Cardiac surgery

Question 17

What is the Best way to position the arm in the supine patient?

Answer 17

Abducted < 90 with hand kind of in the middle (not supinated, not pronated)

Question 18

Are sensory deficits or motor deficits more serious?

Answer 18

Motor

If sensory, ~ tend to resolve on their own. If > 5 days, consult neurology

If motor ~ more serious, can take up to 6 wks to heal ~ will need a neuro cosult

Question 19

Which nerve can be injured as result of traumatic IV insertion?

Answer 19

Median nerve

Question 20

What vascular objects is the median nerve next to?

Answer 20

Basilic vein and median cubical veins

Question 21

What is the only nerve that passes the carpal tunnel?

Answer 21

Median

Question 22

What other conditions can affect the median nerve?

Answer 22

Carpal tunnel syndrome
Elbow hyper extension
Forced elbow extension during positioning after NMB

Question 23

How does a median nerve injury present?

Answer 23

Reduced sensation over palmar surface of thumb, index finger, middle finger, and lateral aspect of ring finger

> unable to oppose thumb
hand of benediction (make a clenched fist)
ape hand deformity

Question 24

What nerve is injured in ape hand deformity?

Answer 24

Chronic median nerve injury

Question 25

What are the 4 most common ways the radial nerve can be injured?

Answer 25

External compression by an IV pole Excessive cycling of the BP cuff Upper extremity tourniquet Sheets that are too tight

Question 26

what is the main presentation with radial nerve injury?

Answer 26

Wrist drop **inability to extend the hand at the wrist

Question 27

Where does the long thoracic nerve arise from?

Answer 27

C5-C7

Question 28

What does the long thoracic nerve innervate?

Answer 28

Serratus anterior muscle (SALT ~ serratus anterior long thoracic)

Question 29

What are some causes of long thoracic nerve injury?

Answer 29

Lateral position Trauma Preexisting neuropathy

Question 30

How does a long thoracic nerve injury present?

Answer 30

Scapular winging

Question 31

How does a suprascapular nerve injury present?

Answer 31

Dull shoulder pain Causes: patient in lateral decubitus rolls onto dependent arm

Question 32

Which nerve is highly susceptible to injury when placed in stirrups?

Answer 32

Common peroneal

Question 33

What is the presentation of a common peroneal nerve injury?

Answer 33

Foot drop Inability to every the foot Inability to extend the toes dorsally

Question 34

How does a obturator injury present?

Answer 34

Inability to addict the leg; reduced sensation over medial aspect of thigh **causes: excessive flexion of thigh, excessive traction during lower abd surgery, forceps delivery

Question 35

How does a femoral nerve present?

Answer 35

Impaired knee extension/hip flexion Reduced sensation over anterior thigh **causes: excessive traction during lower abd surgery

Question 36

How does a saphenous injury present?

Answer 36

Reduced sensation over anteriolateral aspect of leg **causes medial aspect of leg leans against the supporting cradle in the lithotomy position

Question 37

How does a sciatic injury present?

Answer 37

Foot drop **causes: extreme hip flexion or external rotation of the legs, sitting with straight legs

Question 38

What does a pudendal injury present?

Answer 38

Loss of peroneal sensation **causes: compressed against peroneal post on an orthopedic fx table

Question 39

What two nerves can be injured if patients legs are crossed during case?

Answer 39

Sural injury (top leg) Superficial peroneal injury (bottom leg)

Question 40

Which complications are MOST commonly associated with the sitting position?

Answer 40

Mid cervical tetraplegia Paradoxical air embolism

Question 41

When is compartment syndrome most commonly seen?

Answer 41

Lithotomy Risk factors: > surgical time > 2-3 hours > increased BMI > decreased tissue oxygenation (hypotension)

Question 42

What is the treatment for compartment syndrome?

Answer 42

Fasciotomy

Question 43

What is associated with hyper flexion of the neck (chin to chest)?

Answer 43

Midxcervical tetraplegia Ischemia can occur as result of stretching and compression of the mid cervical spinal cord (C5)

Question 44

Which table is better ~ Jackson or Wilson?

Answer 44

Jackson!!

Question 45

What are the 4 tumors likely to occur in the anterior mediastinum?

Answer 45

Thymoma Teratoma Thyroid “Terrible” lymphoma

Question 46

What 3 vital structures can a tumor in the anterior mediastinum compress?

Answer 46

Tracheobronchial tree Pulmonary tree Superior vena cava **these patients may present with super vena cava syndrome (edema of the neck, face, and upper torso)

Question 47

What 3 things worsen tracheobronchial compression?

Answer 47

General anesthesia Supine position PPV

Question 48

What can you do if the airway collapses prior to airway securement in an anterior mediastinum mass?

Answer 48

Position patient laterally or in prone position ***a rigid bronch should be available