Operative Positioning Flashcards
What is the purpose of operative positioning? (list 3)
- comfort
- patient safety
- surgical exposure and or surgical access
Who is responsible for supervising and assuring no nerve or soft tissue injury and minimize physiological changes?
the anesthetist
How should you establish position changes?
gradually, particularly at the conclusion of long surgeries
The most imporant thing an anethetist can do while positon a patient is:
be vigilant!
What needs to be documented in regards to patient positioning?
- baseline ROM
- Intraoperative position
- use of padding
- body position
- checks done and frequency
What is the OR table weight limit?
136kg (200 lbs)
How long is the OR table?
80.7 inches
Is this proper hand position for a supine patient in the OR?
Yes, but be careful that the stuff behind the arm supporting it is not too rigid, otherwise you could damge the radial nerve.
How should the feet be,while in the supine position?
- not hanging off the bed
- heels padded
How do you supply lumbar support while in the supine position in the OR?
- slight flexion of hips and knees
- Pillow under the knees (caution)
- Legs/ feet should not be crossed
- TEDs/ SCDs increase venous return, decrease risk of DVT
- Safety strap
If you put too many pillows under the knees what would happen?
You could obstruct venous blood flow
What are the 5 mechanisms of nerve injury?
- stretching
- compression
- kinking
- ischemia
- transsection
The brachial plexus goes through what 2 fixed points.
- the verterbral foramina fascia
- axilla
What 3 things in the OR for the patient in supine positon, would cause injury to the brachial plexus?
- neck extension or head turned to one side
- when arm board extended or abducted >90 degrees
- arm/ arm board falls of the table (mostly stretching injuries)
What are the symptoms of a brachial plexus injury?
- electric shocks or burning sensation shooting down the arm
- numbness or weak arm
- no or weak motor control of shoulder and elbow
- pain
How does radial nerve damage occur in the OR?
compression of the radial nerve on the lateral aspect of the humerus from surgical retractors, ether screen, mismatched arm board, repeat BP inflation
What is the physiological result of radial nerve injury in the OR?
- wrist drop
- weakness in abduction of the thumb
- numbness 1, 2 ring fingers
What is the most common peripheral nerve injury obtained in the OR?
Ulnar nerve injury
What 2 types of injuries can occur to the ulnar nerve in the OR?
- It is in the cubital tunnel at the elbow groove. Compression of the nerve between the olecranon of the ulna and medial epicondyle of the humerus (entrapment with arm extension)
- Also injured by stretch with severe elbow flexion, dislocation with pronation of the hand, nerve dislocation over medial epicondyle w/stretching, compressing against bed
What 4 things happen with claw hand, what nerve is injured?
Claw hand is an ulnar nerve injury.
- Inability to abduct or oppose the 5th finger
- Weak grip ulnar side of fist
- Loss of sensation to the palmar surface to the 4th or 5th fingers
- Atrophy of intrinsic muscle of the hand (side of the hand)
What can you do to reduce injury to the ulnar nerve? (list 5)
- pad the arm boards
- avoid downward compression by strap
- assure surgical personnell don’t compress the patient’s arm
- Place BP cuff proximally so it doesn’t compress the ulnar groove or cubital tunnel
- Avoid prolonged flexion of the elbow
How common is the occurence of lower extremity nerve damage from the lithotomy position?
1 in 3608 patients
What percentage of lower extremity nerve injuries are to the common peroneal nerve?
78%
What percentage of nerve injuries are to the sciatic nerve?
15%
What percent of nerve injuries are to the femoral nerve?
7%
Lower extremity nerve injuries are most common in what 3 patient populations?
- low body mass index
- prolonged surgery
- recent cigarette smoking
Name the nerve branches.
The common peroneal nerve is a branch of the:
sciatic nerve
The common peroneal nerve lies lateral to the:
neck of the fibula
How does injury to the common peroneal nerve occur in patients in lithotomy position?
Compression of the lateral aspect of the knee against stirrup or if patient in lateral position.
What are the symptoms of common peroneal nerve injury?
- foot drop
- inability to evert the foot
- loss of dorsal extension of the toes
What two things could cause sciatic nerve injury in the OR?
- excessive external rotation of the hips
- pressure on sciatic notch from stretching
What are the symptoms of sciatic nerve injury?
- weakness or paralysis of muscles below the knee
- numbness foot and lateral half of calf
- foot drop
How does femoral nerve injury occur in the OR?
- compression at pelvic brim by retractor
- excessive angulation of the thigh
- abduction of thighs and external rotation of hips
What are the symptoms of femoral nerve injury?
- Loss of flexion of the hip
- Loss of extension at the knee
- decreased sensation over the superior aspect of the thigh
How does saphenous nerve injury occur in the OR?
When medial aspect of lower leg is compressed against support bar
What are the symptoms of saphenous nerve injury?
paresthesias medial and antermedial side of calf.
What causes lower extremity compartment syndrome?
- When perfusion to an extremity is inadequate, resulting in
- ischemia,
- edema, and
- excessive rhabodmyolosis from increased tissue pressure
- occurs with long surgeries (>2-3 hours)
Lower extremity compartment syndrome is associated with which two surgical positions?
- lithotomy
- lateral decubitus
How do you calculate perfusion to the lower extremities?
Perfusion pressure changes 2mmHg for every 2.5cm that a given point varies in vertical height above or below a reference point (the heart).
What is this prone frame called?
Wilson frame, it is good for ventilatory expansion
What is this prone frame called?
Jackson table. There is not base. You can get x-rays very easily
With a head rest with mirror, what should you be watching for?
- eyes
- nose
- airway
- neck alignment
With a horseshoe head rest what do you have to watch for?
- eyes
- nose
- bony structures of face
- airway
- neck alignment
What do we have to watch for with Mayfield head tongs/ pins?
- slippage
- neck alignment
- nose
- metal components touching
What causes corneal abrasions in the OR?
- direct trauma
- dry eye
- swelling
How do you treat corneal abrasions if they occur?
antibiotic ointment, eye patch
What causes blindness in the OR?
- caused by ischemic optic neuropathy via central vein or artery obstruction or via sustained, direct pressure on the eye/retina
- visual changes/ partial or complete blindness
List some risk factors for blindness in the OR via ischemic optic neuropathy?
- prone position
- operative hypotension
- large operative blood loss
- large crytalloid use
- anemia
- smoker
- diabetic
- patients with vascular pathology
- HTN
- male
- microemboli
Which 2 types of surgery place patients at increase risk of ischemic optic neuropathy?
- spinal surgery
- cardiac surgery
