Positioning Part I Flashcards
What are the different supine position varaitions?
- Split leg supine
- Trendelenburg / Reverse Trendelenburg
- Contoured (lawn chair)
- Uterine or abdominal mass displacement
- Lithotomy
What are complications of supine position?
- Arm Complication
- Backache & Paraplegia:
- Axillary Trauma from the Humeral Head
- Radial Nerve Compression
- median nerve dysfunction
- brachial nerve plexus
What are the characteristics of arm complication of supine position?
Check arm boards
What are the characteristics of Backache & Paraplegia of supine position?
- Lumbar backache can worsen by ligamentous relaxation that occurs w/ anesthesia
- Have pt position themselves in a comfortable manner prior to induction
What are the components of the horizontal supine position? (6)
- On back with pillow under head
- Arms: restrained alongside the trunk or abducted on arm boards
- NO skin to metal contact
- NO stretching/compressing of neurovascular bundle @ axilla
- Lumbar spine: supported to prevent postoperative backache
- Bony contact points padded: occiput, elbows, heels
What can also occur with supine horizontal position?
Pressure alopecia resulting from ischemic hair follicles is r/t prolonged immobilization of head and its weight
Review the nerves of the arm.
What are causes of ulnar injury from the supine position?
- Elbows extending over the edge of the operating room table
- Elbow flexed greater than 110 degrees
- External compression (e.g. leaning on patient)
Who is at increased risk of ulnar injury from the supine position?
Male gender, high BMI, prolonged post-operative bedrest
What is the prevention for ulnar injury from the supine position?
–Tucked: Hands should be neutral, with elbow padded and palms facing hips
–Armboards: Forearms should be supinated
–Arms should be abducted no more than 90 degrees
What are the clinical manifestations of Ulnar Neuropathy from supine position?
- Numbness, tingling, or pain in the sensory distribution of the ulnar nerves
- Preanesthetic interview:
- Inquire on hx of ulnar neuropathies, previous elbow surgery/injuries
- Document!!!
What can mask the signs of ulnar neuropathy from supine position?
Opioids may mask pain…
Review Arm Positioning.
https://www.youtube.com/watch?v=1zJ1sCU4VT4
Wbat are the characteristics of the Axillary Trauma from the Humeral Head?
- Abduction of the arm >90° may thrust the head of the humerus into the axillary neurovascular bundle.
- >90°bundle is compressed & stretched
What can happen to vessels with Axillary Trauma from the Humeral Head?
Vessels can be compressed or occluded & perfusion of the extremity can be jeopardized.
Where does Radial Nerve Compression arise?
Arise from C6-C8 & T1
What are causes of Radial Nerve Compression?
- Excessive BP cuff cycle, compression @ midhumerus by restrictive sheets to tuck arms have caused damage.
- Arm boards and slings positioned laterally can directly compress the radial nerve
- Wraps around the musculospiral groove
Where does the radial nerve pass?
Radial n. passes dorsolaterally around the middle and lower portions of the humerus in the musculospiral groove
What are the components of median nerve dysfunction of supine position?
- Uncommon
- Forced elbow extension after administration of muscle relaxants and while positioning the arms, with resultant stretch of the median nerve (potential MOI)
What are the components of brachial plexus neuropathy from supine position?
- Root injuries
- Sternal retraction
- Long Thoracic Nerve Dysfunction
What are the charateristics of root injury from supine position?
- Shoulder braces @ base of neck can injure roots of brachial plexus
- Move more laterally over the acromioclavicular joint
What are the charateristics of Sternal retraction injury from supine position?
- Arms tucked or abducted
- High risk for 1st rib fx & brachial plexus injuries r/t retraction of ribs
What are the characteristics of Long Thoracic Nerve Dysfunction from supine injury?
- LTN: from nerve roots C5-C7
- Postoperative serratus anterior muscle dysfunction & “winged scapula”
What is the Long Thoracic Nerve Dysfunction origin?
Usually traumatic in origin (not routinely involved in a stretch injury)
What are some other supine nerve injuries?
- Radial Nerve Compression
- Superficial Peroneal nerve & Sural nerve injury
What are causes of radial nerve compression?
- Compression along the lateral humerus
- Excessive cycling of BP cuff will be contributive
- Restrictive sheets or towels to tuck the patient
- Surgical retractors
- (radial nerve courses around the humerus)
What are causes of Superficial Peroneal nerve & Sural nerve injury?
Pressure from superior extremity damaging the superficial peroneal nerve in the dependent leg and the sural nerve
Define sural nerve.
posterior calf, lateral ankle, lateral heel, and foot
Define superficial peroneal nerve.
sensory anterolateral leg; motor to peroneus longus & peroneus brevis
Review foot innervation.
What is another names for Supine Position: Contoured?
Lawn Chair Position
What is the component of “Lawn Chair Position”?
Trunk-thigh is approximately 15-degrees & thigh-knee is approximately 15 degrees
What are alternatives to flex of “Lawn Chair Position”?
Alternatives to flex: rolled pillow, towel, pillow, blanket
What are the Supine Position - Life Threatening Complications?
- hypotension and decreased cardiac output are risks with GA (vasodilation and myocardial suppression)
- Supine Hypotensive Syndrome or Aortocaval Syndrome
- Diaphragmatic compression from abdominal weight
What are the characteristics of hypotension and decreased cardiac output are risks with GA (vasodilation and myocardial suppression)?
Risk of hemodynamic changes are minimal in supine position but hypotension and decreased cardiac output are risks with GA (vasodilation and myocardial suppression)
- Light anesthetic or a gradual induction decreases this risk
- Intravascular volume is an option (controversial)
What are components of the Supine Hypotensive Syndrome or Aortocaval Syndrome?
- Body weight can rest on great vessels of the abdomen and compromise circulation
- Place support under right hip or slight table tilt to the left to displace weight
What are the components of Diaphragmatic compression from abdominal weight?
- FRC and total lung capacity significantly decreased due to cephalad shift of diaphragm by the abdominal visceral
“the tube goes where the _______ goes”
Nose
What is the relationship of Supine Hypotensive Syndrome and pregnant women?
In pregnant women, use left uterine displacement (LUD) once uterus is palpated above the umbilicus: wedge under the right buttock to get a 15 degree tilt
Review split leg supine.
What is the use for split leg supine?
Surgical procedures of the abdomen, head, neck, extremities, & chest
What is the true about the base of the surgical table?
Base of surgical table is asymmetric. Torso is over the foot of the table to help facilitate the use of surgical equipment (ie: xray, c-arm)
What are the physiological changes that occur when the legs are elevated?
- Preload increases causing transient increase in cardiac output and a slight increase in cerebral venous and intracranial pressure
- Abdominal viscera displaces the diaphragm cephalad reducing lung compliance & tidal volume
What is the indication of Lithotomy?
Used for surgeries that require access to perineal structures
What are the different types of Lithotomy?
Legs flexed and abducted above torso
- Low lithotomy
- Exaggerated lithotomy
- Hemilithotomy
Define Low lithotomy.
Legs level with torso
Define Exaggerated lithotomy.
Feet well above body
Define Hemilithotomy.
One leg elevated
What is the characteristics of Lithotomy placement/removal?
Both legs should be elevated and lowered simultaneously to avoid hip dislocation, spinal torsion and postop back pain
What is the location of the arms of Lithotomy?
Arms tucked at sides or on arm boards at <90 degrees
What do you need to be mindful of in the Lithotomy?
- Be mindful of fingers.
- They may lie near the open edge/hinge point of the lowered section of the tale .
- When raising the foot at end of surgery, strict attention to avoid a potential crush injury to fingers.
What can occur in the lithotomy position?
Nerve Injury
Where do nerve injuries occur in the Lithotomy positon?
Acute abduction and external rotation of hips may cause femoral nerve or lumbosacral plexus stretch injuries
What can occur with flexing hips >90 degrees in the Lithotomy?
Flexing hips >90 degrees may cause stretching of sciatic and/or obturator nerves
What is peroneal nerve injury secondary to in the Lithotomy?
- Peroneal nerve injury common secondary to leg holding devices (compression of nerve against fibular head
- Results in weakness of ankle eversion, dorsiflexion and sensory disturbances of the dorsal foot
- Saphenous nerve also at risk
What position can acute compartment syndrome occur?
- The potential cause of the injury is compression of the nerve b/t the lateral head of the fibula and the bar holding the legs
- Compartment syndrome from prolonged use of the lithotomy position with use of supportive devices
Define compartment syndrome.
“Lower extremity ACS (acute compartment syndrome) is a pathologic condition in which increased tissue pressure within a closed osseofascial space compromises blood circulation and normal function of tissues within the compartment leading to tissue hypoxia and necrosis”
What can be used to maintain lithotomy position?
Candy canes
What are components of low Lithotomy Position?
- Simultaneous access to abdomen & perineum
- Thigh elevation is approx. 30-45°
What are components of high Lithotomy Position?
- Improved access to perineum
- Legs almost fully extended on the thighs & thighs flexed 90°or more on the trunk
- Uphill gradient for arterial perfusion into feet (avoidance of systemic HYPOtension)
What are yellow fins?
- Legs should be removed from the holder simultaneously, knees brought together in the midline and the legs slowly straightened and lowered onto the operating room table.
What is the indication for Lithotomy Position: Exaggerated?
Transperineal access to the retropubic area
What is the position of Lithotomy Position: Exaggerated?
- Pelvis flexed ventrally on the spine, thighs forcibly flexed on the trunk\
- Lower legs aimed skyward & out of the way
What is a respiratory effect of Lithotomy Position: Exaggerated?
Uphill gradient for perfusion of the feet, restrict ventilation secondary to abdominal compression
What is high risk with Lithotomy Position: Exaggerated?
High association with lower extremity compartment syndrome
What needs to be maintained with Lithotomy Position: Exaggerated?
Maintain adequate perfusion pressure in the legs
What is a Life Threatening/Concerning Injuries with lithotomy?
Compartment syndrome
How does lithotomy position increase risk of compartment syndrome?
Lower legs at risk if procedure extends beyond 2-3 hours
Local arterial pressure _____________ above the right atrium
decreases by 0.75mmHg per cm change in height
What are risk factors for lithotomy?
■Advanced age
■Extremes of body habitus
■History of nerve ischemia or neuropathy
■Connective tissue disease
■Anemia
■Hypotension
■Use of vasoactive drugs
What are the treatments for lithotomy?
Treatment is fasciotomy
What is Lateral Decubitus position used for?
- Used for surgeries involving the thorax and kidneys when supine position cannot provide sufficient exposure
- Also used for orthopedic procedures involving the hips, shoulders, or extremities for better access to surgical site
How is Lateral Decubitus Positioning named?
Named for down side, for example: left lateral decubitus (left side down)
What are the types of Lateral Decubitus Positioning? Where is the kidney located?
- Can have a standard lateral decubitus position or flexed lateral decubitus position with the kidney rest elevated
- Kidney rest should lie under the dependent iliac crest
What are the components of Lateral Positions: Standard?
■Upside thigh and leg are extended & pillows are placed between the lower extremities
■Support/align cervical and thoracic spines
■Axilla roll
■Arms extended or flexed
■Straps across the hip (between iliac crest & head of femur)
■Bean bag to maintain position
Why is the downside knee bent in the lateral standard position?
Downside knee is bent to improve stabilization of the trunk (common peroneal n.)
Why are Ancillary positioning devices important in the Lateral Decubitus Position?
Ancillary positioning devices (e.g. beanbags, pillows, sandbags, braces, adhesive tape, etc.) aid in securing the patient and preventing rotation of the trunk
Lateral Decubitus Position: Flex knee and hip of _______ leg to stabilize patient
dependent
Where does the Lateral Decubitus Position non dependent leg remain? What does this reduce?
- Non-dependent leg remains straight and supported by a pillow placed between the lower extremities to prevent bony prominences of the legs from resting on each other
- Reduces compression of the inferior leg by the superior extremity
Where should padding occur in the Lateral Decubitus Position?
Padding placed along lateral aspect of dependent leg from knee to heel to protect peroneal nerve from external pressure against table or beanbag
What is the alignment of the Lateral Decubitus Position?
- Shoulders, hips, head, and legs are maintained in the same plane and turned simultaneously to avoid stress and twisting of the torso and spine
- Head and neck remain aligned with the spine in a neutral position
- Head should be supported on pillows or a donut
- Dependent eye end ear must be free of pressure
What can be used for upper extremity positioning of the Lateral Decubitus Position?
- Overhead armboard
- Pillow(s)
Where should the pulse ox be in the Lateral Decubitus Position? What can a low sat indicate?
- SpO2: Monitored in the dependent arm for early detection of compression to axillary neurovascular structures
- A low saturation reading may be an early warning of compromised circulation
Where is the blood pressure measured in the Lateral Decubitus Position?
HYPOtension measured in the dependent arm may be 2/2 axillary arterial compression (useful to retain the ability to measure both arms) - Measure NIBP in nondependent arm
What are Lateral Decubitus Position - Common Injuries?
- compress the common peroneal nerve of the dependent leg
- Brachial plexus injury
- pressure on the axillary neurovascular bundle.
*
What are the characteristics of compression of the common personeal nerve?
- The weight of the superior leg pushes against the dependent extremity and may compress the common peroneal nerve of the dependent leg against the operating table
- Place padding under the fibular head
What are the characteristics of the brachial plexus injury?
Brachial plexus injury most commonly the result of excessive stretching, usually because of arm abduction greater than 90 degrees, external rotation, extension and lateral flexion of the head, and posterior should displacement
What are the components of strap placement and brachial plexus injury in the lateral decubitus position
- If tape or straps are used to stabilize the torso place caudal to the axilla to reduce the risk of injury
- Placement across the ribs can impair ventilation and soft tissue injury may occur if straps or tape is overly tight
What are the characteristics of pressure on the axillary neurovascular bundle in lateral decubitus?
- Weight of the chest can compress the lower shoulder and axilla putting pressure on the axillary neurovascular bundle
Maintain a natural shoulder rotation when you move arms to protect the _________.
suprascapular nerve
What needs to be periodically assessed in the lateral decubitus position?
- Perfusion to the upper extremities, especially the dependent arm, should be periodically assessed
- Palpating radial artery and check capillary refill
Where is the blood pressure measured in lateral decubitus position?
Use nondependent arm for non-invasive blood pressures because of the potential for neurovascular compression in the dependent arm
What may need to happen to the patient in lateral decubitus position?
If nondependent arm is suspended on an arm holder or with traction abduction of 45-60 degrees should be maintained and less than 10 pounds of traction applied
What are the Lateral Decubitus Position - Life Threatening Concerns/Injuries?
Sustained hypotension
rhabdomyolysis
What are the characteristics of sustained hypotension in the lateral decubitus position?
- Having the blood pressure cuff on the nondependent arm decreases blood pressure by 10mmHg or more
- Obtaining a pre-op blood pressure and blood pressure in the supine position once the patient arrives to the OR will establish a baseline blood pressure aiding in prevention of hypotension
Preventing hypotension will aid in preventing ___________
rhabdomyolysis
What are associated factors with rhabdomyolysis?
prolonged OR time, hypotension, and pressure of the OR table against gluteal and flank muscles
What happens in a long procedure that can cause rhabdomyolysis?
During long procedures, ensure weight of the body is not causing external compression of dependent tissues leading to states of low tissue perfusion
What needs to be monitored to determine rhabdomyolysis?
- Closely monitor urine output
- If suspected send labs to measure creatinine kinase, myoglobin in blood and urine, an elevated potassium, and elevated creatinine
How do you treat rhabdomyolysis?
- Fluid replacement with bicarbonate to flush out myoglobin
- Dialysis if kidney damage and acute renal failure are suspected
What are hemodynamic affects of Lateral Decubitus Position?
- Hypotension is likely with kidney rest elevation because legs are dependent
- When the legs are dependent, venous return is reduced from the extreme flexion
- Kidney rest may depress the great vessels
What are the respiratory efects of the lateral decubitus position?
Patients susceptible to atelectasis because closing volumes occur above FRC with closing occurring earlier in the dependent than in the nondependent lung
What is the effect of tidal volumes in the lateral decubtius position?
Tidal volumes of 10-12mL/kg and an FiO2 of 0.5 or higher have been suggested to compensate for V/Q mismatch in the lateral position
What can excessive tidal volumes cause?
Beware excessive tidal volumes can cause barotrauma, decrease hypoxic vasoconstriction, and reduce oxygenation
What is the effect of one lung ventilation in the lateral decubitus position?
- V/Q mismatching may affect oxygenation, especially with one lung ventilation
- Hypoxic pulmonary vasoconstriction in the non-ventilated lung further redistributes blood flow to the dependent lung
Lateral decubitus one lung ventilation: What can be given to dependent lung?
Can give PEEP of 5cmH2O to dependent lung to stent the alveoli open
Lateral decubitus one lung ventilation: What can be given to nondependent lung?
Can give CPAP of 5-10cmH2O to nondependent lung
What is the pulmonary compromise of Lateral Decubitus Position – One Lung Ventilation?
- Mechanically ventilated, the combo of the lateral weight of the mediastinum & disproportionate cephalad pressure of abdominal contents on the dependent lung favors overventilation of the nondependent lung.
- Pulmonary blood flow to the under ventilated, dependent lung increases owing to the effect of gravity.
- V/Q (vent/Perfusion) mismatching and potential affecting gas exchange and ventilation.
What are the characteristics of the Flexed Lateral Positions: Lateral Jackknife?
- Downside iliac crest over hinge between back and thigh sections of table
- Uppermost portion of pt’s flank and thorax becomes horizontal
- Feet are below the level of the atria & significant amount of blood pooling in leg vessels
- Position used to widen intercostal spaces of lumbar
The Flexed Lateral Positions: Lateral Jackknife has ____ use
Limited use
What is the charactersitics of the Flexed Lateral Positions: Kidney?
Resembles the lateral jackknife PLUS elevated kidney rest (under downside of iliac crest)
What effect is seen in the Flexed Lateral Positions: Kidney?
Increases amount of lateral flexion & improve access to upside kidney
What can be effected in the lateral position?
- Eyes & Ears
- Neck
Whast can happen to patient’s ears in the lateral position?
Weight of head can press on ear (NO folding of ears)
Whast can happen to patient’s eyes in the lateral position?
Direct pressure to eye > ocular abrasions, displaced lens, increased IOP, ischemia
Whast can happen to patient’s neck in the lateral position?
Step away to visualize
When is a right mainstem intubation likely to occur?
Right mainstem intubation with flexion of neck and Trendelenburg when repositioning after intubation:
Axillary roll placed just ______ to the dependent axilla to relieve pressure in lateral decubitus.
caudal
