Operative positioning

Question 0

1) What should your documentation be composed of?

2) How can you avoid liability?

Answer 0

1) Documentation- describe baseline range of motion, describe intra-operative position, use of padding, frame, body position, checks done and frequency, etc.
2) Liability- avoided by responsible, vigilant care; documentation

Question 1

What is the purpose of operative positioning?

Answer 1

●Comfort
●Patient Safety
●Surgical Exposure and/or Surgical Access

Question 2

What is the weight and length limit of the OR table?

Answer 2

136 kg (300 lbs) and 80.7 inches (205 cm or 6.7 ft)

Question 3

Why is the supine position most common operative position and the Position preferred by anesthesia providers?

Answer 3

1) access to airway
2) access to arms for IV’s/monitors
3) less physiologic changes than in other positions

Question 4

Why would you want to put a pillow under the head when a patient is in the supine position?

Answer 4

–Allows proper sniffing position
–Avoids dorsal extension and lateral flexion of neck
–Doughnut shape pillow - avoids alopecia
–No pressure on eyes

Question 5

What should you do with the arms when a patient is in the supine position?

Answer 5

1) Tuck arm: Draw sheet under pt. hip or torso, NOT mattress; elbow padded; palm in.

2) Arm boards
•Properly secured to OR table
•Abducted < 90 degrees, avoids stretch brachial plexus
•Padded
•Safety straps
•Hands- supinated (palm up) NOT pronated

Question 6

What should you do with the feet when a patient is on the supine position?

Answer 6

1) Heels not hanging over bed

2) Heels padded

Question 7

How can you provide a lumbar support when a patient is on the supine position?

Answer 7

1) Slight flexion hips and knees
2) Pillow under knees (caution)
3) Legs/feet should not be crossed
4) Elastic compression stockings and SCD/ sequential compression devices- increase venous return/ decrease risk DVT

●Safety strap

Question 8

What are the mechanisms of nerve injury?

Answer 8

1) Stretching
2) Compression
3) Kinking
4) Ischemia
5) Transection

Question 9

How can injury to the brachial plexus occurs in the supine position?

Answer 9

1) neck extension,or head turned to side
2) excessive abduction of arm > 90 degrees
3) arm/ arm board falls off table: Mostly stretching injuries

Question 10

What are the deficit seen when the brachial plexus is injured in supine position?

Answer 10

1) electric shocks or burning sensation shooting down arm,

2) numbness or weak arm function

Question 11

How can radial nerve injuries occur in a supine position?

Answer 11

Injury due to external compression of the radial nerve on the lateral aspect of the humerus against
–Surgical retractors
–Ether screen
–Mismatched arm board (“step off”)
–Repeat BP inflation

Question 12

What is the results of a radial nerve injury in a supine position?

Answer 12

Injury results in wrist drop/ weakness in abduction of the thumb/ numbness 1, 2, ring fingers, inability to extend elbow

Question 13

What is the most common postoperative peripheral nerve injury in supine position?

Answer 13

Ulnar Nerve

Question 14

Where and how does injury to the ulnar nerve occur when a patient is in the supine position?

Answer 14

1) In cubital tunnel @elbow groove – compression of nerve between the olecranon of ulna & medial epicondyle of humerus (entrapment with arm extension)
2) Also, injured by stretch with severe elbow flexion, dislocation with pronation hand, nerve dislocation over medial epicondyle w/ stretching, compression against bed

Question 15

What is the result of ulnar nerve injury in supine position?

Answer 15

1) Inability to abduct or oppose 5th finger
2) Weak grip ulnar side of fist
3) Loss sensation palmar surface 4th or 5th fingers
4) Eventually, leads to atrophy of intrinsic muscle of hand (claw hand)

Question 16

How can you reduce the risk of ulnar injury in a supine position?

Answer 16

1) Pad arm boards
2) Avoid downward compression by strap
3) Assure surgical personnel do not compress patient’s arm
4) Place BP cuff proximally so that it does not impose on ulnar groove or cubital tunnel
6) Avoid prolonged FLEXION of elbow

Question 17

What are some Cardiovascular changes seen in a supine position?

Answer 17

MINIMAL effects on circulation and perfusion.

1) Initially, have increased venous return to heart
–Increased preload, stroke volume, CO, BP
–This activates baroreceptors which decrease sympathetic outflow and increases parasympathetic impulses
–Compensatory decreases HR, PVR
2) Reduced venous drainage from lower extremities – uncross legs, pad heels, pillow beneath knees, flexed hips and knees = all improve venous return

3) IVC compression by masses, pregnancy, obese abdomen or ascites may decrease venous return to the right heart and decrease cardiac output.

Question 18

What are some ventilatory changes seen in the supine position?

Answer 18

1) FRC decreases +/- 800 ml, r/t cephalad displacement of the diaphragm and compression of lung bases
2) Lung volumes further reduced by muscle relaxants
–Loss of chest wall muscle tone with muscle relaxants – reduces opposition to inherent elastic recoil of pulmonary tissues.
–Overcome with positive pressure ventilation.

Question 19

What are some cerebral blood flow changes seen in supine position?

Answer 19

Minimal change r/t “tight” autoregulation

Question 20

Why would want to put a patient in a tredelenberg position?

Answer 20

1) Used to treat hypotension by increasing venous return
2) Improves surgical exposure during abdominal and laparoscopic surgery
3) Helps prevent air embolism
4) Facilitates cannulation during central line placement

Question 21

What are some precautions you be thinking when a patient is on tredelenberg position?

Answer 21

Use EXTREME caution with shoulder braces! - if they must be used they should be well padded and placed laterally away from the root of the neck over the arcomioclaviular joint

Question 22

What are some cardiovascular changes seen in patients on tredelenberg position?

Answer 22

1) Used to counteract hypotension - controversial (short term only)
–Increases venous return to the heart - up to 1L into central circulation
2) Causes reduced blood flow to the lower extremities
3) May cause compression of heart by abdominal contents pushing cephalad
4) Baroreceptors activated – peripheral vasodilation and bradycardia- may make “shock syndromes” worse in the long run

●What happens when the supine position is resumed?

Question 23

What are some ventilatory changes seen in tredelenberg position?

Answer 23

1) Contents of the abdomen displaced cephalad impeding diaphragmatic excursion, compresses lung bases, decreases lung compliance, decreases FRC, PIP increases.
2) With spontaneous ventilation, work of breathing is increased.
3) V:Q mismatch with perfusion exceeding ventilation in the apex of the lung.
3) ETT is easily shifted into right mainstem bronchus as abdominal/thoracic contents shift cephalad.
4) Risk of aspiration
5) Face and airway edema can lead to airway obstruction

Question 24

What are some cerebral blood flow seen in tredelenberg?

Answer 24

1) Increases intracranial vascular congestion- GRAVITY!!! 2) INCREASED INTRACRANIAL PRESSURE-- 3) Intraocular pressure increases. 4) Who would NOT be a good candidate for this position? CNS disease and glaucoma.

Question 25

When would you want to use the reverse trendelenberg position?

Answer 25

1) Utilized to enhance surgical exposure of the upper abdomen by shifting the abdominal contents caudad. – ex. laparoscopic cholecystectomy 2) Variations of this position may be used for shoulder, neck, intracranial surgery. 2) This is a variation of the sitting position in terms of physiologic changes.

Question 26

What are some precautionary measure with using the reverse trendelenberg position?

Answer 26

Caution with foot board Excessive plantar flexion of the feet for extended periods of time –Anterior tibial nerve injury –Results in foot drop

Question 27

What are some precautionary measures when using the reverse trendelenberg position?

Answer 27

●Caution with foot board 1) Excessive plantar flexion of the feet for extended periods of time 2) Anterior tibial nerve injury 3) Results in foot drop

Question 28

What are some cardiovascular changes seen in reverse trendelenberg position?

Answer 28

1) Reduced preload, CO, and lowered BP. 2) Compensatory increased SNS tone, SVR, and HR +/- 30% (may be blunted by anesthetics) 3) Activation of the renin-angiotensin-aldosterone system 4) Venous pooling in the lower extremities- compression stockings good idea ●What happens when the supine position is resumed? Activation of the renin-angiotensin-aldosterone system ●Venous pooling in the lower extremities- compression stockings good idea ●What happens when the supine position is resumed?

Question 29

What are some ventilatory changes seen in reverse trendelenberg position?

Answer 29

1) Abdomen does not impede diaphragmatic excursion, FRC increases. 2) Ventilation is easier.

Question 30

What are the effects on cerebral blood flow with reverse trendelenberg position?

Answer 30

1) Cerebral blood flow decreases proportional to the degree of head up tilt (can be up to 20%). 2) Intracranial pressure decreases 3) What patients would this position benefit? Measure BP at the circle of Willis.

Question 31

Explain the right patient position with the calf support stirrups methods in lithotomy position?

Answer 31

1) Hips flexed 80-100 degrees 2) Legs abducted 30-45 degrees from midline 3) Lower legs parallel to torso 4) Watch femoral, sciatic, lower leg nerves

Question 32

Explain the right patient position for candy cane stirrups with the lithotomy position?

Answer 32

Like the calf support stirrups but 1) Usually more acute flexion of the knees and/or hips 2) Watch injury to common peroneal nerve, sciatic, femoral

Question 33

Explain the right patient position for knee crutch style with the lithotomy position?

Answer 33

Same as the Candy cane and calf support stirrups but Watch popliteal nerve (tibial nerve and common peroneal nerve)

Question 34

A) What is the occurrence of lower extremity nerve injury with lithotomy position? B) which patients are more at risk for lower extremity nerve injury with lithotomy position?

Answer 34

A) 1) 1:3608 patients 2) 78% common peroneal* 3) 15% sciatic 4) 7% femoral B) Most common with: low body mass index, prolonged surgery, recent cigarette smoking, PVD, DM, obesity

Question 35

1) Which procedures are lithotomy positioning commonly used? 2) What happened with improper lithotomy position? 3) What is the proper technique to place a patient in lithotomy position?

Answer 35

1) GI, GU, and Rectal procedures. 2) Improper positioning may lead to the following nerve injuries: femoral, sciatic, obturator, lateral femoral cutaneous, saphenous, common peroneal*. 3) Both legs are positioned into stirups together to avoid torsion of the lumbar spine and hip flexion beyond 110 degrees is avoided –Flexed at hip +knee and simultaneously elevated and separated

Question 36

1) In the lithotomy position, what nerve of the lower extremity is commonly damaged? 2) How can that nerve be injured? 3) What are the symptoms with common peroneal nerve injury?

Answer 36

1) Common peroneal nerve, branch of sciatic, lateral to neck of fibula. 2) Compression of lateral aspect of knee against stirrup or lateral position 3) foot drop, inability to evert the foot, loss of dorsal extension of toes

Question 37

1) How can sciatic nerve injury occurs with the lithotomy position? 2) What are the consequences of sciatic nerve injury?

Answer 37

1) excessive external rotation hips; pressure in sciatic notch from stretching 2) weakness or paralysis of muscles below knee; numbness foot & lateral half of calf; foot drop

Question 38

1) How can femoral nerve injury occurs in the lithotomy position? 2) What is the results of femoral nerve injury?

Answer 38

1) Injured with compression at pelvic brim by retractor or excessive angulation of thigh/ abduction of thighs and external rotation of hips 2) Results in loss of flexion hip and loss of extension of knee; decreased sensation over superior aspect thigh

Question 39

1) How can saphenous nerve injury occurs with lithotomy position? 2) What is the results with saphenous nerve injury?

Answer 39

1) Occurs when medial aspect of lower leg (medial tibial condyle) is compressed against support bar. 2) Results in paresthesias medial and antermedial side of calf.

Question 40

Name three factors that can increase the risk of lower extremity compartment syndrome?

Answer 40

1) Occurs when perfusion to an extremity is inadequate, resulting in ischemia, edema, and extensive rhabdomyolysis from increased tissue pressure 2) Occurs with long surgical procedures (> 2-3 hours) 3) Occurs with lithotomy and lateral decubitus positions

Question 41

What should you be careful of when your patient is in the lithotomy position?

Answer 41

Incorrect hand position. Fingers can be crushed or amputated when the leg section of the table is elevated.

Question 42

What are some cardiovascular changes seen with lithotomy position?

Answer 42

1) Elevation of legs increases venous return/ increases preload to heart with transient increase in CO and increase in BP 2) Perfusion to the lower extremities is reduced! –*Perfusion pressure changes 2 mm Hg for each 2.5 cm that a given point varies in vertical height above or below the reference point (heart).

Question 43

What are some ventilatory changes seen with lithotomy position?

Answer 43

1) Depending on the degree of hip flexion, abdominal contents may push up on the diaphragm and impede excursion, with a reduction of lung compliance and decrease TV and decrease in vital capacity. 2) Aspiration risk increases.

Question 44

What are some cerebral changes seen with lithotomy position?

Answer 44

Transient increase in cerebral venous blood flow and increase in intracranial pressure with legs elevated

Question 45

What should you watch for when a patient is in prone position with the head rest with mirror?

Answer 45

Watch eyes, nose, airway, neck alignment

Question 46

What should you watch for when a patient is in prone position with the horseshoe head rest?

Answer 46

Watch eyes, nose, bony structures of face, airway, neck alignment

Question 47

What should you watch for when a patient is in prone position with the mayfield head tongs/ Pins?

Answer 47

Watch for slippage, neck alignment, nose, metal components touching

Question 48

When placing a patient in the prone position, when can you do while patient is still on the Stretcher?

Answer 48

1) Induction /intubation 2) Line placement 3) NGT/OGT, esoph steth, bite blocks 4) Foley 5) Good eye protection 6) Secure everything ●To disconnect or not to disconnect monitors??

Question 49

What are some clinical considerations when proning a patient?

Answer 49

``` ●CHECK BREATH SOUNDS AGAIN ●Monitors on and working ●Check IV and Aline working ●Check for excessive pressure on –eyes, nose –upper extremities –breasts –genitals, ant. iliac crest ●Chest and hips supported to allow for free abdomen for diaphragmatic movement and increased venous return ●Check neck alignment ```

Question 50

When proning a patient, how should you maintain the head?

Answer 50

●Head may be turned to side if adequate mobility ●Head supported face-down with its weight on bony structures ●Neck is neutral alignment, not excessive flexion or extension ●Eyes, nose, ears free of pressure

Question 51

What the two main eye injury seen in the prone position?

Answer 51

1) Corneal abrasions –Direct trauma, dry eye, swelling –Treatment antibiotic ointment, eye patch, 2) Blindness –Ischemic Optic Neuropathy •Via central vein or artery obstruction •Via sustained, direct pressure on the eye/retina –Visual changes/ Partial or complete blindness –Risk factors include prone position, operative hypotension, large operative blood loss, large crystalloid use, anemia, smoker, diabetic, patients with vascular pathology or HTN, male –Caution in spinal surgery and cardiac surgery

Question 52

What should you do with the extremities when a patient is in the prone position?

Answer 52

``` 1) Arms: ●On boards by head ●Abducted less 90 degrees ●Extra padding at elbow ●Prevent shoulders from sagging ●Watch for thoracic outlet syndrome ●Tucked at sides ``` 2) Legs: ●Slightly flexed ●Elastic compression stockings/ SCD

Question 53

What is a thoracic outlet syndrome?

Answer 53

Compression at the superior thoracic outlet resulting from excess pressure placed on a neuromuscular bundle passing between the anterior scalene and middle scalene muscle.

Question 54

What are some cardiovascular changes seen in prone position?

Answer 54

1) IVC and Aortic Compression- hypotension –Rolls or similar devices free the abdomen and chest improving flow. 2) Venous pooling in lower extremities- hypotension –Leads to decreased preload, C.O. and BP –Elastic compression stockings/ SCDs 3) Hypotension associated with the move to prone position must be anticipated, monitored and treated as necessary. –Prolonged hypotension in addition to pressure on the face/eyes may lead to blindness!!

Question 55

What are some ventilatory changes seen in the prone position?

Answer 55

1) V:Q mismatch: Posterior ventilation>perfusion Anterior perfusion >ventilation 2) Cephalad displacement of diaphragm. Lung compliance decreases. Peak airway pressures increase. Work of breathing increases. 3) USE ROLLS/BOLSTERS- frees chest excursion Positive Pressure Ventilation overcomes compression effects

Question 56

What are the effects seen with cerebral blood flow in prone position?

Answer 56

1) Turning head obstructs venous drainage leading to increased cerebral volume and ICP. 2) Excess flexion or turning - obstruction of vertebral artery flow.

Question 57

1) When should you use the lateral decubitus position? | 2) What are some requires special positioning with the lateral decubitus?

Answer 57

1) Used for – thoracotomy, kidney, shoulder, and hip surgery. 2) Head support- neutral position- avoid misalignment of cervical spine, stretch brachial plexus –Limited pressure on dependent eye & ear –Axillary roll (chest roll or chest support)- placed caudad to & outside of lower axilla

Question 58

When a position is in the lateral position how should you positioned the arm and legs?

Answer 58

1)Arms –Dependent arm on padded arm board perpendicular to torso – Non-dependent arm supported over folded bedding or suspended with armrest 2) Legs –Padding between knees and flexed dependent leg (saphenous nerve injury) –Padding on bed (common peroneal nerve injury) ●Anterior/posterior support-bean bag/hip posts ●Safety strap- between head of femur & iliac crest

Question 59

What are some cardiovascular changes seen in the lateral position?

Answer 59

Minimal change 1) No change in C.O. unless venous return is obstructed (kidney rest against vena cava). 2) Noninvasive BP cuff measurements will be different in two arms –Higher in dependent arm –Lower in nondependent arm

Question 60

What are some ventilatory changes seen in lateral position? 1) Awake and spontaneous breathing 2) Anesthetized but spontaneous breathing 3) Anesthetized, mechanically ventilated patient

Answer 60

1) Awake and spontaneous breathing –Dependent lung is both better perfused and better ventilated, but lung volumes (FRC, VC, TV decrease) 2) Anesthetized but spontaneous breathing –Nondependent lung better ventilated and dependent lung is better perfused (V/Q mismatch) 3) Anesthetized, mechanically ventilated patient –Nondependent lung is overventilated and dependent lung is overperfused (worse V/Q mismatch)

Question 61

When is the sitting position used in the OR?

Answer 61

Used for cranial surgery, shoulder & humeral procedures - Facilitates venous drainage - Excellent surgical exposure/access

Question 62

What are some considerations related to head positioning in the sitting position?

Answer 62

1) Fixed in pins or taped in place 2) Avoid excessive cervical flexion- obstructs venous outflow causing hypoperfusion or venous congestion in the brain, stretch cervical nerve roots, can obstruct ETT, can place pressure on the tongue (swelling) 3) Want atleast 2 FB between mandible and sternum 4) Avoid rigid bite-block – tongue ischemia

Question 63

What some considerations related to the arms, buttocks, knees and feet in the sitting position?

Answer 63

●Arms –Avoid pressure on frame –Support arms- avoid traction pulling down on shoulders (brachial plexus injury) ●Buttocks- positioned in break of table ●Flex knees & hips- decrease stretch of sciatic nerve ●Elastic compression stockings/ SCD ●Feet supported and padded

Question 64

What are some cardiovascular changes seen in the sitting position?

Answer 64

1) Pooling of blood into lower extremities decreases preload, C.O. and BP. 2) HYPOTENSION! 3) HR and SVR increase as a compensatory measure (blunted by anesthetics). 4) Treatment: IVF, vasopressors, adjustments of anesthetic depth, elastic stockings and active leg compression devices

Question 65

What are some ventilatory changes seen in the sitting position?

Answer 65

1) Lung volumes and capacities increase. 2) Lung compliance increases 3) Work of breathing easier 4) Mechanical ventilation and spontaneous ventilation easier in this position.

Question 66

How would cerebral blood flow affected in the sitting position?

Answer 66

●GRAVITY!!! 1) Cerebral blood flow decreased 2) Intracranial pressures decreased 3) Watch positioning which can impede arterial and venous blood flow, causing hypoperfusion or venous congestion of the brain

Question 67

What are some considerations related to venous air embolism in the sitting position?

Answer 67

1) VAE is a risk ANY TIME the surgical site is above the level of the heart !!! 2) Inability of venous sinuses to collapse 3) it is a potentially LETHAL complication! 4) Signs of VAE include: change in heart tones (wind mill murmur) heard via doppler placed at the parasternal border (2nd-6th IC space), new murmur, dysrhythmias, hypotension, desaturation, DECREASED EtCO2, Nitrogen in exhaled gas, circulatory compromise, and cardiac arrest 5) Detection of entrained air with TEE or precordial Doppler ultrasound

Question 68

What are some treatment for venous air embolism?

Answer 68

1) Flood surgical field with NS, apply wax to cut bony edges, close any open vessels 2) D/C nitrous oxide 3) Place on 100% O2, PEEP 4) T-berg position 5) Aspirate air from right atrium via a catheter