Positioning Flashcards
Standard 8
patient positioning collaborate with the surgical or procedure team to position, assess, and monitor proper body alignment; use protective measures to maintain perfusion and protect pressure points and nerve plexus
Claims analysis for positioning injuries
- liability and nerve injury
- ulnar nerve and brachial plexus most common
- ulnar nerve injury and GA
goals for positioning
- patient safety
- optimize surgical exposure
- preserve patient dignity
- maintain hemodynamic stability
- maintain cardiorespiratory function
- no ischemia, injury, or compression
- 2015 joint commission patient safety goal #14 to prevent healthcare associated pressure ulcers
volatile anesthetic effect on CV system
- decreased CO
- decreased BP
NMBDs effect on CV system
- decreased muscle tone
- decreased VR
opioids effect on CV system
-decreased HR –> decreased CO and BP
CV concerns with positioning
- redistribution of circulating blood volume
- depressed CO
- reduced preload and thus SV
- blood pooling in dependent areas
- compression of extremities or great vessels
- impaired ANS function
- anatomy cephalad to heart risk hypoperfusion and/or ischemia
pulmonary concerns with positioning
- barriers to thoracic excursion/expansion (supine/lateral/prone = chephalad displacement; prone = reduced capacity for chest expansion)
- positive pressure ventilation
- gravity related effects (ventilation - nondependent; perfusion - dependent)
- loss of HPV with anesthesia
mechanisms associated with nerve injury
- compression (force nerve against bony prominence or other hard surface)
- transection (nerve cut)
- stretch (nerve pulled tightly)
- traction (nerve pulled over or under immovable structure like a bone)
nerve sheath ischemia
- direct (r/t compression)
- indirect (like compartment syndrome)
risk factors for nerve injury
- DM
- HTN
- PVD
- alcohol abuse
joint commission patient safety goal for skin
prevent development of pressure ulcers, assess and reassess patients for pressure ulcer risk, address identified risks
risk factors for pressure injuries
- age (elderly - thin skin, decreased circulating time, poor mobility)
- DM
- PVD
- surgical time
- chronic hypotension
- increased body temperature
- body habitus
- smoking
- infant (large head, occiput a risk)
supine
- arms secured (armboards, padding, arm straps)
- arms laterally or abducted
- arms <90 degrees
- supinated forearm and pad elbow
- legs flat, uncrossed
- heel padding
- equipment/monitors padded
- consider small lumbar support
- palmar aspects hands parallel to thighs/trunk
- pillow under knees
why do we keep arms <90 degrees?
to avoid a stretch brachail plexus injury
why do we supinate the forearms in supine position?
- avoid ulnar nerve compression
- pronation could cause ulnar nerve compression at cubital tunnel of elbow
why do we put a pillow under the knees?
avoid sciatic nerve stretch
supine CV implications
- BP stability
- compensatory mechanism of ANS reduced (i.e., decreased SNS response)
supine respiratory implications
- reduced TLC and FRC
- diaphragm shifts cephalad
- general anesthesia and NMBDs enhance effects
prone (ventral decubitus)
- often intubated, so do induction/intubation on stretcher
- head/neck neutral
- arms < 90 derees
- elbow flexed free of pressure
- body/trunk support with foam/pillows
what is the number 1 priority after any movement change?
reassess the airway placement
what types of surgical cases would we use the prone position?
- spine
- buttocks
- rectum or peri-rectal
- ankle
- intracranial
prone CV implications
- pooling of blood in lower extremities and dependent areas of gut/abdomen
- compression of inferior vena cava
- epidural engorgement
prone respiratory implications
- decreased compliance if chest not freely hanging
- increased FRC - improved posterior lung ventilation may increase oxygenation
prone… be cautious with
- genitalia (penis)
- breasts
- lower legs
- face
- eyes
- nose
- boney prominences
POVL
postoperative vision loss
POVL causes
- most often occurs in the prone position
- prolonged surgical time spine surgeries (prone)
- most common cause –> ischemic optic neuropathy (ION)
- central retinal artery occlusion (CRAO)
- central retinal vein occlusion (CRVO)
- cortical blindness
ION
ischemic optic neuropathy
89% of POVL –> most common cause!!!
POVL prevention
- surgical duration < 6 hours
- 10-15 degree head up (reduces orbital edema and thus compression of nerve)
- BP 20% of preoperative baseline (MAP > 70 mmHg, anything less than this have potential for adverse effects)
- maintain Hct > 25; if not there is a reduction in O2 carrying capacity
ischemic optic neuropathy risk factors
-extended surgical time
-extensive blood loss
-obesity
-gender –> male
-wilson frame
-decreased OPP (ocular perfusion pressure)
NOTE –> not associated with globe pressure
OPP
ocular perfusion pressure
OPP = MAP - IOP
CRAO
- central retinal artery occlusion
- eye stroke
- presentation - sudden, profound vision loss; painless
- etiology - embolism, vasculitis, vasospasm, sickle cell, trauma, glaucoma
- dx - retinal pallor; macular cherry red spot
- consult optho + neuro
CRVO
- central retinal vein occlusion
- eye dvt
- presentation - variable from blurred vision to sudden vision loss; painless
- risk factors - typical stroke risk factors, hypercoagulable states, glaucoma, compression of vein in thyroid or orbital tumors
- dx - optic disc edema; diffuse retinal hemorrhages
- no specific treatment, consult optho + neuro
lithotomy
- legs elevated and abducted
- fingers free of footboard (IMPT bc dont want compression)
- less free –> peroneal nerve!!!
- hip flexion - prevent sciatic/obturator nerve stretch; femoral nerve palsy
lithotomy procedures
- perineal structures
- gynecological
- urology
lithotomy CV implications
- 20% reduced FRC
- reduced VC
- hypoventilation breathing spontaneously
- increased intra-abdominal pressure
lithotomy respiratory implications
- increased (shifted) central blood volume
- autotransfusion 250-300 mL/leg when raised
lateral
- head neutral, supported
- pressure off eyes, ears, and face
- shoulders, hips, head and legs aligned
- chest and hip supports or bean bag
- regularly assess perfusion
- dependent arm (down arm) on padded arm board, perpendicular to torso <90 degrees
- nondependent arm (up arm) axillary roll under dependent side of thorax, slightly caudad, not directly in axilla
lateral surgical procedures
- kidney
- shoulder
- orthopedic (THA, hip)
- thorax
lateral CV implications
- optimize volume status (euvolemic), minimal changes
- kidney rest elevated –> slowly under iliac crest, great vessels compressed, decrease venous return
lateral respiratory implications
- VQ mismatch possible
- FRC - increased in nondependent lung (top) and decreased in the dependent lung (bottom)
- dependent lung lower than LA, prone to atelectasis and fluid accumulation
sitting surgical procedures
- cervical spine surgery
- shoulder surgery
- posterior fossa
- breast reconstruction
sitting
- HOB 30-90 degrees above horizontal plane
- OR table flexed and backrest elevated
- head secured (ensure 2 fingerbreadths between neck and mandible)
- endobronchial intubation (careful because if head flexion occurs ETT can advance in up to 1.9 cm)
- dislodge head from headrest with vigorous surgical manipulation
- pad heels, legs flexed (prevent sciatic stretch)
- arms secured (padded arm boards or patient’s lap with drawsheet)
sitting complications
- VAE
- pneumocephalus
- quadriplegia
VAE
- venous air embolism
- most commonly occurs in the sitting position
- RA and operative site veins incidence ~1-74%
- fatal amount of air = 0.5-1 mL/kg
S/S VAE
- sudden decreased ETCO2
- decreased BP
- decreased SpO2
- increased CVP
- air visualized on TEE
- if patient awake –> dyspnea, respiratory distress, meal-wheel murmur, pulmonary HTN
what to do if have a VAE?
- get the code cart and call for help!!
- durant position - trendelenbery with L lateral decubitis – allows air emboli to rise to top of RA and NOT go to lungs
- if have a CVC, aspirate air from RA
pneumocephalus
- the presence of air in the epidural, subdural, or subarachnoid space, within the brain parenchyma or ventricular cavities
- can occur in neuro procedures, often benign
Quadriplegia
- spinal cord stretched when head is flexed + loss of autoregulation with general anesthesia
- ensure 2 fingerbreadths of space between neck and mandible … limits strain at C5
sitting CV implications
- reduced SV and CO (up to 20% reduced)
- decreased MAP and CVP
- lower extremity venous pooling
- decreased cerebral perfusion, CPP = MAP - ICP
sitting respiratory implications
- increased FRC
- increased compliance
trendelenburg
- head down
- degree of trendelenberg will determine the amount of dependent edema and the physiologic/hemodynamic impact
- increased –> ICP, IOP, CVP, and BP in dependent extremities
- shoulder braces
- normal or steep
shoulder braces too wide
brachial plexus stretch
shoulder braces too narrow
brachial plexus compression
reverse trendelenburg
- bed flat, head up
- increased pulmonary compliance and FRC
- decreased ICP, IOP, CPP, BP
- common in laparoscopic procedures
brachial plexus injury
- can occur in supine or lateral decubitus position
- in supine, arms abducted >90 degrees or humoral head rotated
- in lateral decubitus there can be stretch, traction, or tension of brachial plexus; also chest can cause compression of dependent arm (down arm)
S/S brachial plexus injury
- weakness in arm
- diminished reflexes
- sensory deficits
CRNA role positioning
- calls turns/repositioning
- ensure patient stability
- EVERYONE is responsible
when positioning avoid
- excessive pressure on peripheral nerves and bony prominences
- eye pressure, abrasions, irritants
- extremitiy injury
- strain/dislocation of joints/muscles
when positioning ensure
- adequate circulation
- head and neck support
- airway protection
- anatomical alignment
- access
