Position Flashcards
position general
- crna responsible, done for safety and comfort,
- slow changes at end of case
- can evoke undesirable physiological changes
documentation 5 positioning
- ROM prior to case
- intra op position
- frame/padding
- actually position
- frequent checks
transfer to OR table
- stretcher and OR table next to each other both locked
- OR table has draw sheet
- staff on both sides
- self transfer or assistance
- head aligned and watch extremities
Supine
most common -less physiological changes that others -has access to airway and arms (IVs) -no pressure on eyes -pillow under head: for better sniffing position and avoids dorsal extension/lateral flexion of neck (doughnut shaped pillow--avoids alopecia
Supine arms, feet, lumbar
- arms tucked- palm in, pad elbow, use draw sheet to tuck arms under torso (not mattress)
- Arm board-abduct less than 90 to avoid brachial plexus stretch, hands Palm Up SUPINATED (protects ulnar nerve)
- Feet: heels not hanging off bed and padded
- Lumbar: (all this improves venous return) hips and knees flexed, pillow under knees (caution for DVTs, but helps with low back pain)
- Legs not crossed, compression stockings/SCDs
CV changes in Supine
minimal effects
- initially increase venous return to heart,
- *increased preload, SVR, CO, BP which activates baroreceptors and PSN outflow so compensatory decrease HR and PVR
- Decreased venous drainage for lower extremities
- *IVC compression by masses: preg (put on L), ascities, obesity–may decreased venous return to heart and decreased CO
Ventilatory changes in Supine
FRC decreased 800ml
- diaphragm displacement and compression of lung bases
- and Muscle relaxant: decrease lung volume and loss of chest wall muscle tone.
Cerebral blood flow changes in Supine
minimal–tight autoregulation
mechanisms of nerve injuries 5 and diseases
STICK
- Stretching
- Transection
- Ischemia
- Compression
- Kinking
- Obesity, DM, Smoking
Brachial plexus injury (supine) cause and deficits(general)
-neck extension or head turned to side
-excessive abduction of arm >90
-arm falls of table
Deficits:
-electric shocks or buring sensation shooting down arm
-numbness or weakness in arm
1 and 2 injured
1 ulnar #2 brachial
Radial nerve injury (supine)
-external compression to radial nerve on lateral aspect of humerus from:
–surg retractor
–ether screen
–uneven arm boards
–repeat BP
Result:
-wrist drop
-weakness in abduction of them
-numbness in 1,2,3 digit
-inability at extending elbow
Ulnar injury
- most common injury
- in cubital tunnel in elbow groove
- Compression btwn olecaron and medial epicondyle–entrapment with arm extension
- Stretch with severe arm flexion
- Stretch with dislocation with pronated hand (dislocated over medial epicondyle)
- 3Xmore common in men
Ulnar injury symptoms
Claw hand
- inability to abduct or oppose 5th finger
- weak grip on ulnar side of fist
- Loss of sensation on palmer side of 4th and 5th finger
- eventually leads to atrophy of intrinsic muscles of hand
Reduce rick of Ulnar injury
- pad arm board
- avoid compression with strap
- assure surg personnel dont compress
- make sure BP cuff is Proximal (not in ulnar groove)
- Avoid prolonged elbow flexion
Trendelenberg
- used to treat hypotension by increasing venous return
- improves surg exposure in abd and lap surg
- *helps prevent air embolism with central line placement
- shoulder braces- used with EXTREME caution–away from the neck over AC joint
CV changes in trendelenberg
- short term for hypotension, increased Venous return..up to 1L
- decreased blood flow to lower extremities
- compression of heart
- activation of Baroreceptors: peripheral vasodilation and decreased HR (can make shock worse)
- *return to supine: slowly, decreased BP, venous pooling
Vent changes in Trendelenberg
- abd contents displace: impeding diaphragm
- -compressing lung bases
- -decreased lung compliance
- -decreased FRC and increase PIP
- Increase WOB (spot breathing)
- V/Q mismatch– increase perfusion in apex
- aspiration risk
- facial/airway edema
- ETT can become R mainstem
Cerebral blood flow Trendelenberg
- *IICP
- IIOP
- increased vascular congestion-gravity
- *CNS disease pt- NOT good candidate
Reverse Trandelenberg
Enhance surgical exposed of upper abd–shifting content down ex lap chole
- -Variation of this position use for Neck, shoulder and intracranial surg
- for physiological change– its a variation of sitting
- FOOT board: caution- excessive planter flexion for extended period of time– can cause Anterior tibial nerve injury–FOOT Drop
CV changes in Reverse Trendelenberg
decreased CO(20-40%), Preload, BP
-compensatory increase SNS tone, SVR and HR(30%) **this may be blunted by anesthetics
-Activation of renin-angiotensin-aldosteron system
-Venous pooling in lower extremities (compression stockings)
Return to supine: increased CO secondary to increased venous return
Lithotomy position
-calf support stirrups
-hips flexed 80-100degrees
-Legs abduct 30-45 degrees
-lower legs parallel to torso
-can Pinch femoral
-or Stretch sciatic
-or compress peroneal nerve
-Used for:
GYN, GU, Rectal procedures
*both legs in stirrups to avoid torsion of lumbar
-AND hip flex beyond 110 is avoided
-when positioning: elevate together then separate
Candy cane stirrups
usually more acute flexion of hip and knees
watch for nerve injuries: femoral, sciatic, peroneal
Knee crutch
can injury the popliteal nerve
common perennial
tibial
Lower extremity nerve injury
1 in 3608 pt 78% common peroneal.. most common lower 15% sciatic 7%femoral -Most common with low BMI, prolonged surg, smoking, DM, PVD, obesity
Improper positioning in Lithotomy can lead to
nerve injuries: femoral, sciatic, obturator, lateral femoral cutaneous, saphenous, common peroneal
Common Peroneal Nerve Injury
-most frequent lower nerve damaged
-branch of sciatic, on lateral side of fibula
*injury for compression to lateral side of leg to stirrup
Symptoms: foot drop, inability to evert foot, loss of dorsal extension of toes
Sciatic nerve injury
-Excess external rotation of hips
-S/S: weakness or paralysis of muscles below the knee, numbness of foot and lateral 1/2 of calf
Get foot drop
Femoral Nerve injury
Compression at pelvic brim by retractor -excessive angulation of thigh abduction -external rotation of hips S/S loss of extension of knee -decreased sensation over superior aspect thigh
Saphenous Nerve injury
-medial aspect of lower leg compressed against support bar
S/S: parasthesia of medial an antermedial side of calf
Lower extremity compartment syndrome
- When perfusing of an extremity is inadequate
- Results in ischemia, edema,
- Externsive rhabdomyolysis from increased tissue pressure
- occurs with long cases (>2-3hrs)
- occurs with lithotomy and lateral decubitus position
CV changes with Lithotomy
increased venous return
-increased preload
-transient increase in CO and BP
perfusion in lower extremities is decreased
**each 2.5cm vertically above heart needs 2mmhg more pressure to perfuse.
Vent changes in Lithotomy
-depends on the degree of hip flexion–can displace abd content up therefore
-decreasing lung compliance
decrease TV and vital capacity
-aspiration risk
Cerebral flow changes in lithotomy
- transient increase in cerebral venous blood flow
- increase in ICP with legs elevated
Prone position
- wilson frame
- jackson table
- head rest with mirror- can watch eyes, airway, neck, nose
- Horseshoe head rest- Watch bony structures of face
- Mayfield head tongs and pins: watch for slippage, neck alignment, nose—touching metal components
Prone: On stretcher you…8
- intubate
- line placement
- NGT/OGT
- esoph steth,
- bite blocks
- foley
- good eye protection
- To disconnect or not to disconnect monitors??
- Anesthesia is in charge of the head/airway
Prone: on Table
- **Check Breath Sounds FIRST, have help and can flip them back over if need to
- monitors on and working
- Check IV and aline
- check for excessive pressure on eyes, nose, upper extremities, breast, genitals, ant. iliac crest.
- chest an abd support to allow for free abd–helps diaphragmatic mvmt and increased venous return
- Neck in neutral alignment, no excessive flexion or extension
- can turn head to side if pt has mobility to do so
- eye, nose, ears free of pressure
Prone: eye injury
-corneal abrasions: direct trauma, dry eyes, swelling TX: abx, eye patch
-Blindness: ischemic optic neuropathy
–via central vein or artery obstruction
–via sustained, direct pressure on eye/retina
-can result in visual changes or complete blindness
Risk factors other than prone: operative hypotension, lg OP blood loss, anemia, smoker, DM, HTN, male,
**caution in cardiac and spinal surg
Prone: extremities
- Arms: on boards by head, padding, including the elbow, abduction less than 90, prevent shoulders from sagging
- Legs: slightly flexed, SCDs
Thoracic Outlet syndrome
at risk in prone,
-Check by having pt put hands behind head for 2 minutes—see if numbness or tingling, check pulse–if yes to numbness than must tuck arms.
CV changes in Prone
- ICV and aorta compression–Hypotension
- -Rolls to free abd and chest will improve flow
- Venous pooling in lower extremities–hypotension, SCD, elastic compression
- Hypotension associated with the move must be anticipated and tx if necessary
Vent changes in Prone
V/Q mismatch:
- Post vent>perf
- Anterior perf>vent
- cephalad diaplacement of diaphragm
- lung compliance decreased
- increased peak airway pressure
- Increased WOB
- use rolls
Cerebral blood flow change in prone
- turning head obstructs venous return leading to increased cerebral volume and IICP
- excess flexion or turning-obstruction of vertebral artery flow
Lateral decubitus Position (lots-o-info, arms, legs)
used for: thoracotomy, kidney, hip, shoulder surg
-requires: head support-neutral position (avoid, misalignment of cervical spine and stretch of brachial plexus)
-Limited pressure on dependent eye and ear
-Axillary roll- placed ciudad to outside of lower axilla **keep axilla clear
ARMS: dependent arm on padded arms board perpendicular to torso
–non-dependent supported with blankets or suspended with armrest
LEGS: -padding in btwn knees and flexed dependent leg (saphenous nerve injury)
-padding on bed common peroneal nerve injury
ANTERIOIR/POSTERIOR support:
-bean bags, hip post
-safety strap btwn head of femur and iliac crest
CV changes in lateral D
minimal, no changes in CO unless obstruction in venous return (kidney resting against vena cava)
Higher BP in dependent
Vent changes in lateral D
- awake and spent breathing
- dependent lung gets better perfusion and vent
- decreased FRC, VC, TV
- anesthetized but spont breathing
- nondependent lung better vent
- dependent lung better perfusion
- Anesthetized mech breathing
- same as above but OVER vent OVER perf
- -Worse V/Q mismatch
Cerebral blood flow changes in lateral D
minimal unless extreme flexion of head
Sitting head, arms, butt, feet
used for cranial, shoulder & humeral surg (good exposure/access)
-facilitates venous drainage
HEAD: fixed in pins, or taped in place
-avoid excess Cervical flexion:
–obstructs venous outflow–causing hypoperfusing or venous congestion of brain
–stretch cervical nerve roots
–obstruct ETT
–can place pressure on tongue..must have 2 finger breaths btwn mandible and sternum
ARMS: avoid pressure on frame, traction pulling down on arms (brachial)
BUTTOCKS- postion in break of table
-flex knees and hip to decreased stretch in sciatic
FEET- support, padded SCD
CV changes in Sitting
-pooling of blood in lower extremities
-Decreased CO, BP, preload
*hypotension
-HR, SVR increased as a compensatory measure (can be blunted by anesthetics)
TX: IVF, vasopressors, adjustment of anesthetic depth, SCD
Vent changes in sitting
good
-increased: lung volumes, capacities, compliance
-WOB easier
everything easier (spont, mech)
Cerebral blood flow changes in Sitting
Gravity
- decreased CBF
- decreased ICP
- watch positioning-can lead to impediment of arterial and venous blood flow, causing hypoperfusion or venous congestion of brain.
Venous air embolism VAE
risk anytime the surgical site is above the heart
-inability of venous sinus to collapse
**can be Lethal
S/S: changes in heart tones–windmill murmur
heard via doppler placed @parasternal border (2-6IC space)
-dysrhythmias, hypotension, desat **decreased ETCO2, nitrogen is exhalled
circulatory compromise and cardiac arrest
VAE detection and Tx
-detection of entrained air with TEE or precordial doppler ultrasound
Tx: flood surgical field with NS
-apply wax to cut bony edges, close any open vessels
-D/C nitrous (bc it expands air pockets)
-place on 100% O2 PEEP
-T-berg position
-aspirate air from R atrium via catheter
