Exam 2 - Positioning Flashcards
What 3 things should we consider r/t positioning?
- the positioning process from head-toe
- proper positioning devices
- how much help is needed
What should be used in the abdominal/pelvic area to secure the patient?
How many finger breadths should be underneath these?
- safety belts/straps
- 2 finger breadths (or nerve damage & decreased flow can happen)
What is the most common surgical position?
Supine
Supine
How are the arms positioned?
- arms tucked
- or out to the side on secured arm boards
Supine Position
Pathophysiologic Considerations
- Increased venous return, preload, SV, CO
- Decreased Vt & FRC
* FRC = ERV + RV
Supine Position
Why don’t we see the initital pathophysiologic changes?
- They are transient
- d/t mechanoreceptors & baroreceptors sensing the changes and taking the v/s back to baseline
Supine Position
Arms Abduction
- arms out to the side <90 degrees
- padded arm boards secured to the table & pt @ axilla
- arms should be supine w/ palms up
- elbows padded & arms secured w/ velcro strap
Supine position
Which is better - underpadding or overpadding under gaps?
*** over padding **
* under padding leads to problems
Supine Position
Arms Adduction
- tucked alongside the body
- held via draw sheet - goes up in b/w arm & body and is tucked over the arm
With the arms adducted in the supine position, how should the palms be positioned?
- hand & forearm are supine (palms up)
- neutral position w/ palms toward the body
What are the 5 complications r/t Supine positioning?
- backache
- pressure alopecia
- brachial plexus or axillary nerve injury if arms abducted > 90 degrees
- Ulnar nerve injury if hand/arm is pronated (palm down w/ arms adducted)
- Stretch injury when neck is extended & head turned away (brachial plexus)
Supine complications
Why do people experience back pain w/ this position?
- lumbar lordotic curvature lost and they lose tone of the paraspinal muscles
** extra padding will not help **
Supine complications
What can help pts with kyphosis/scoliosis/back pain Hx?
Extra Padding
* support the neck
Supine complications
What causes pressure alopecia?
What can we do to help prevent this?
- decreased flow & excessively long cases
- lift their head, massage, give their scalp some breathing room
- use donuts
Supine complications
What is the most common nerve injury with the supine position?
- brachial plexus (keep the arms below shoulder level & 90 degrees)
What is the trendelenburg position?
What is an example surgery it would be used for? (Ericksen mentioned)
- same as supine w/ head tilted down to diff. steepness levels (slight - extreme)
- Robotics Davinci case
Trendelenburg position
What can we do to prevent the pt from sliding cephalad (toward HOB)?
- use non-sliding matress/pad under the pt
- mark the sheet to see if the pt slid down
Trendelenburg position
Why do we need to avoid the use of bean bags/shoulder braces?
- they will lead to brachial plexus/compression injuries
Trendelenburg pathophys changes
What happens w/ CO?
CO increases d/t increased venous return of blood from lower extremities
Trendelenburg pathophys changes
What happens w/ ICP & IOP?
- increased ICP & IOP
- pts @ risk for increased ICP - communicate w/ surgeon to minimize trendelenburg steepness
Trendelenburg pathophys changes
What can cause an increase in edema of the face, conjunctiva, larynx, & tongue?
- surgical time & fluid overload - assess the face & oral cavity
Trendelenburg pathophys changes
What does intraabdominal pressure do?
- increases
- everything pushes up on the lungs & shifts cephalad
trendelenburg pathophys changes
What happens w/ FRC & pulmonary compliance?
- they decrease
- diaphragm shifts cephalad
- vent settings may need to be adjusted per pt (esp. if obese)
– PC vs. VC - they may need higher pressures
Trendelenburg pathphys changes
What increases the risk of endobronchial intubation?
- abdominal contents push the carina cephalad
- the tube can shift & go R mainstem
assess the ETT & listen to breath sounds
What is the reverse trendelenburg position?
- same as supine, tilting head of patient up & feet down
- use non-sliding mattress/pad under pt
- footrest or something under feet to prevent sliding
– no risk of nerve injury
Reverse Trendelenburg
Pathophysiologic changes
- HoTN - decreased venous return (pooling in LE)
- down displacement of abdominal contents & diaphragm
– good for pts hard to ventilate (increased FRC) - decreased perfusion to brain
Reverse Trendelenburg Pathophys Changes
If the pt is in the sitting position or with the head up - where does the arterial line need to be leveled?
- level of the tragus
- to know they are getting good flow to the brain
Sitting Position
What needs to happen with the pts head? How do we do this?
- head stabilized
- taped to special head rest or use rigid pins (surgeon)
Sitting Position
How are the pts hips & feet positioned?
- hips flexed < 90 degrees w/ knees slightly flexed
- feet are supported to prevent sliding
Sitting position
What does having the knees/hips flexed do for the pt?
- prevents nerve compression & decreased flow to LE
- reduces stretching of the sciatic nerve
Sitting Position
What does keeping 2 finger breadths b/w the chin & sternum do?
- reduces flexion of cervical spine
- need to maintain the head neutral & midline
- maintains normal blood flow
How is beach chair position different from the sitting position?
What cases is beach chair position typically used for?
- beach chair has less hip flexion and only slight leg flexion
– this gives a reduced risk of sciatic nerve stretching & reduced flow risk - commonly used for shoulder surgeries
What are 5 major risks associated with the sitting position?
- Cerebral hypoperfusion & air embolism
- pneumocephalus
- quadriplegia & spinal cord infarct
- cerebral ischemia
- peripheral nerve injuries (sciatic nerve injury)
Sitting position risks
What can cause an air embolism?
What can an air embolism lead to?
- Neurosurgery - venous sinuses can entrain air (5mL/kg needed to have major issues)
- Can lead to -
1. arrhythmias
2. O2 desat
3. pulm. HTN
4. circulatory comprise
5. cardiac arrest
Sitting Risks
What causes a pneumocephalus?
What can that lead to?
- entrainment of air in the subdural or ventricular space
- can cause pressure on the intracranial structures/sinuses
Sitting Risks
What can cause quadriplegia & spinal cord infarct?
- significant flexion of the head forward or to the side
important to maintain neutrality & normal flow
– arterial flow & venous drainage
Sitting Risks
What can cause cerebral ischemia?
- permissive HoTN
- reduced CO
- surgeon will want lower BP in shoulder cases - tell them to screw off
Sitting position
What pathophys changes happen?
- HoTN - decreased venous return from venous pooling in LE
- decreased MAP, CI, & CPP
– important to maintain normal flow - improved ventilation b/c they are sitting up
– FRC is better
Prone position
How are the arms positioned?
- side tucked or outstretched (< 90 degrees)
- flexion @ elbows
Prone position
How is the head positioned?
- head supported face down w/ prone pillow
- horseshoe headrest
- rigid fixation w/ pins in neutral position w/o pressure on eyes, nose, mouth, & ears
- maintain neutrality to prevent occluding jugular veins or any arteries
Prone position
We need to avoid compression of the pts ________, ________, & ________.
- breasts
- abdomen
- genitalia (men)
prone position
How should the legs be positioned?
- padded & slightly flexed @ knees & hips
- compressions stockings to prevent pooling of blood
Prone Images
What are 5 risks associated w/ the prone position?
- facial & airway edema
- nerve injuries
– ulnar if elbows not padded
– brachial if arms abducted > 90 degrees - post-op visual loss (decreased perfusion/ischemia)
– eye injury r/t head position (maintain neutrality) - ETT dislodgement
- loss of monitors & IV lines
Prone pathophysiological changes (3)
- edema of face, conjunctiva, larynx, & tongue
-
increased abdominal pressure
– decreased venous return (compression of IVC)
– decrease CO -
improved ventilation
– ventilation & perfusion in the lungs shift to the dependent areas (dependent areas have better ventilation)
Lithotomy Position
- pt lying supine w/ legs up in “padded” or “candy cane” stirrups
- if using trendelenburg or reverse - need non-sliding mattress
Lithotomy position
how are the arms positioned?
- tucked or on arm boards
- make sure hands are not in crack of bed
- make mittens for the hands
- prevent crush injuries
Lithotomy position
How are the lower extremities positioned?
- hips flexed 80-100 degrees
- legs abducted 30-45 degrees from midline, knees flexed
- lower extremites must be raised/lowered in synchrony - prevents torsion of lumbar spine
- foot of bed lowered
Lithotomy position
If surgery is > 2-3 hours what should we do w/ ROM?
- periodically lower the legs
- LOL the surgeon ain’t gonna let you do that
What are 3 risks associated w/ lithotomy position?
-
back pain
– similar to supine (loss of paraspinal muscle tone) -
nerve injuries
– brachial plexus, ulnar nerve, common peroneal, lateral femoral cutaneous -
compartment syndrome
– not common (wraps too tight on legs)
Lithotomy Pathophysiological Changes
- increased venous return, CO, ICP
-
increased intraabdominal pressure
– displaces diaphragm cephalad -
decreased lung compliance & Vt
– decreased FRC
– ventilation issues (esp. if large panus/belly)
What is the lateral decubitus position?
pt lying on non-operative (dependent) side
* requires anterior & posterior support w/ rolls or bean bags
* ex: right lateral decubitus = right side down, left side up
Lateral Decubitus position
How should the head be positioned?
- adequate head support needed
- ensure no pressure on eyes/ears
– check dependent ear regularly - maintain neutrality
Lateral Decubitus Position
How should the arms be positioned?
- in front of the pt
- both must be supported
- abducted < 90 degrees
- ax roll placed b/w chest wall & bed, caudal to axilla - @ the nipple line
Lateral Decubitis Position
What is the purpose of the axillary roll?
- prevents brachial plexus compression & neurovascular compression
- prevents “sleeping on the arm/dead arm”
- maintains normal blood flow to the arm
Lateral Decubitus Position
How should the lower extremities be positioned?
- dependent leg should be slightly flexed
- must place padding b/w the knees
Lateral Decubitus - Jack Knife
Where is the ideal location for the bed to be flexed in jack knife or if kidney rest is used?
under the iliac crest
* IVC compression can occur
* this also allows for best expansion of the dependent lung
Lateral Decubitus
Airway concerns
- ETT dislodgement
- LMA - iGel is the best option (need it to be seated well)
Lateral Decubitus Pathophysiological Concerns
-
venous pooling in LE
– use compression sleeves - V/Q mismatch d/t inadequate ventilation to dependent lung & decreased blood flow to non-dependent lung
What causes most peripheral nerve injuries?
What is the timing that they can occur?
- result of stretch, pressure, and/or ischemia
- mechanism unclear sometimes - do everything right & still happens
- can happen in as little as 30 min
Are peripheral nerve injuries sensory or motor?
- most are sensory
- can be motor & sensory
- temporary or permanent
Prevention of Ulnar Nerve Injury (2)
- avoid excess pressure on postcondylar groove of humerus
- keep hand & forearm either supinated or in a neutral position
Prevention of Brachial Plexus Injury w/ Trendelenburg
- avoid use of shoulder braces/bean bags
- avoid abduction of arms when possible
Prevention of Brachial Plexus Injury (4)
- avoid excess lateral rotation of head in supine/prone position
- limit abduction of arm to < 90 degrees in supine
- avoid high ax-roll placement in decubitus position to avoid neurovascular complications
- use US to locate IJ for central line placement
Prevention of Spinal Cord and Lumbosacral Nerve/Root/Cord Injury (3)
- be aware that the fraction of spinal cord injuries is increasing (regional anesthesia)
- avoid severe cervical spine flexion or extension when possible
- follow current guidelines for regional anesthesia in pts on anti-coagulant therapy
Preventionof Sciatic & Peroneal Nerve Injuries (4)
- minimize time in lithotomy
- 2 assistants to coordinate leg movemement to lithotomy
- avoid excess flexion of hips, extension of knees, or torsion of lumbar spine
- avoid excess pressure on peroneal nerve @ fibular head
List the nerve injuries from most common to least common
- Spinal Cord (25%)
- Brachial plexus (19%)
- Lumbosacral nerve/root/cord (18%)
- Ulnar Nerve (14%)
- Sciatic & Peroneal Nerve (7%)
