Positiong Part II Flashcards
What is the prone positioning used for?
Used for surgical access to posterior skull, posterior spine, buttocks, perirectal area, lower extremities.
What are the characteristics of prone position?
- Torso supported on a frame or with rolls that extend from the shoulders to the iliac crest
- supports placed crosswise at the pelvis and shoulders
- Lower legs are supported with pillows
- Upper extremities tucked at sides or supported on armboards with the arms flexed at the shoulders and elbows
- Breasts and genitalia must be positioned to limit pressure
What needs to be assessed prior to prone position?
- Assess preoperative range of motion
- Head, neck, shoulder, and arm mobility
- Arm placement may be limited by ankyloses of shoulder or elbow joints
What is the patient transfer components to the prone position?
- Patient anesthetized on the gurney
- Log-rolled onto the bed, frame, or rolls with good body alignment maintained
- Planning of monitor placement
- Remove monitors or have them remain in situ
- Disconnected from the breathing circuit to avoid accidental extubation
What is anesthetisa’s role in the prone position transfer?
–Control airway
–Control head and neck
–Coordinate turn
What needs to be checked when in/moving to the prone position?
- Keep neck inline with spine
- Make sure you have enough extension on all lines/circuit
- Reassess immediately after the move for endotracheal tube position and adequate ventilation
What are the CVP effects in the prone position?
Positioning devices that allow abdomen to hang freely associated with greater decreases in inferior vena cava pressures than those that compress the abdomen
What are the LV volume effects in the prone position?
Reduced secondary to decreased venous return and increased intrathoracic pressure
What are the CI effects in the prone position?
May be decreased or unchanged in prone position compared with the supine
What are the V/Q effects in the prone position?
- More lung volume is present posteriorly then anteriorly
- Anterior mediastinal structures occupy significant space
- Posterior lung segments are better ventilated
- Ventilation is more uniform and ventilation-perfusion matching is better in the prone position (compared with supine position)
What are the changes in elastance and resistance of diaphragm and abdomenin the prone position?
- Diaphragmatic excursion can be limited by abdominal viscera if the abdomen is compressed by the weight of the body or positioning devices
- If abdomen hangs free gravity allows the abdominal contents to shift reducing interference with diaphragmatic movement
What are the effects of lung capacity in the prone position?
Increase in FRC when the abdomen hangs free
What causes swelling in the head?
Prone and Trendelenburg positions may increase venous pressure in the head with resultant swelling of facial, pharyngeal, and orbital structures
What can cause increased ICP?
Intracranial pressure can be elevated when the head is dependent b/c venous pressure is transmitted to the head and intracranial structures through the valveless jugular systems
What can cause decreased CBF ?
CBF can be decreased when inflow is limited by venous congestion in intracranial structures
What effect can Prone position have on the eyes?
Postoperative visual loss (POVL) may result from an increase in ocular venous pressures and concomitant decrease in ocular perfusion pressure
What can occur in the prone and head down position?
Facial edema, macroglossia, and airway edema may occur following prone and head-down positions
What can prevent facial edema?
10-degree head-up tilt may prevent development of facial edema
Describe the different prone positions in this picture
- A – Classic prone position with torso supported on chest rolls
- B – Jackknife prone position
- C – Prone knee to chest position
What occurs in the A prone variation position?
A - Prone position with Wilson frame
Arms abducted <90 degrees; pressure points padded; chest and abdomen supported away from the bed to minimize abdominal pressure and preserve pulmonary compliance; foam head pillow has cutouts for eyes and nose and a slot to permit the ETT to exit; eyes checked frequently
What occurs in the B prone variation position?
B - Mirror system
Bony structures of head and face supported; monitoring of eyes and airway facilitated with a mirror
What occurs in the C prone variation position?
C - Prone position with horseshoe adapter
Head height adjusted to position neck in neutral position
What occurs in the D prone variation position?
D - Prone position with horseshoe adapter as seen from below
- Horseshoe adapter permits access to airway and visualization of eyes
- Width may be adjusted to ensure proper support by facial bones
What needs to be done to the head in prone position?
Head in neutral position. If lateral rotation may compromise carotid or vertebral arterial blood flow or jugular venous drainage.
Mayfield pinning= _____________
NO movement
What can happen to the abdominal in the prone position?
- Pressure can force the diaphragm cephalad & impair ventilation
- If intra-abdominal pressures approach or exceed venous pressure, return of blood from the pelvis and lower extremities is reduced or obstructed
- Increased difficulty with hemostasis
_________ abdominal pressure!
Remove
Where should the trunk be placed in the prone position?
Elevate trunk off supporting surface (free ventral abdominal wall)
What can the SCDs do in the prone position?
SCD minimizes pooling of blood and supports venous return
What can T-berg occur in the prone position?
T-berg: venous and lymphatic stasis in the head (facial & airway edema)
Ischemic optic neuropathy = __________
vision loss
Where should the breast be placed in the prone positioning?
Breast placed medial to the bolsters
How should the arms be in the prone position?
“Surrender Position”/ “Superman Position”:
Extended ventrally at the shoulder, flexed at the elbow, abducted onto arm boards
What does the superman position prevent?
No tension at shoulders
What should happen to the ulnar n. and the pulses in the prone positioning?
- Ulnar n. @ elbows should be padded
- Pulses @ wrist should be full
What is the andrew’s frame?
What is the Wilson’s frame?
What cam cause a brachial plexus in the prone injury?
- Arms abducted more than 90 degrees
- Abduct arms minimally
- Inadequate support of shoulders allows them to sag anteriorly causing traction on the plexus
- Extending the arms over the head may compress the plexus between the clavicle and first rib
What happens to ocular venous pressure during surgery?
- Head-down tilt
- Increased abdominal and right atrial pressure
- Obstruction of jugular venous return
Where should the head be placed in the prone position to avoid visual loss?
Head should be placed in neutral position (avoid excessive flexion) and level with or slightly elevated above the heart (10-degree head-up tilt)
What preventative devices can be used to help prevent vision loss in the prone positioning?
■Horseshoe adapter least preferred head support technique because of pressure on the eye and risk for POVL
■Foam head pillows w/ cutouts are preferred
What patients are at high risk of POVL?
length procedure in the prone or steep Trendelenburg position, esp. if surgery is accompanied by significant blood loss
What is associated with prone position?
–Hemiparesis and quadriplegia (spinal cord injury) are associated with prone positions
What is not present in the intervertebral veins that can cause issues in the prone positioning?
–Valves are not present in the intervertebral veins that drain the vertebral and spinal cord venous plexuses into the lumbar veins
Where is external abdominal pressure is transmitted to?
–External abdominal pressure is transmitted to the vena cava and communicated to the lumbar epidural veins
What can engorged epidural veins cause?
- Engorged epidural veins are fragile and easily traumatized
- Ensuing blood loss will decrease surgical exposure and contribute to hypotension
What are airway complications can occur in the prone injury?
- ETT
- Edema
What is the ETT components that can occur in the prone position?
- Displaced, kinked, or disconnected when patient is moved for position change
- Right main stem intubation may occur as a result of flexion of the neck
What is the edema components that can occur in the prone position?
- Extensive edema of the face, tongue, and oropharyngeal structures
- Gravitational forces or increases in hydrostatic pressure may restrict venous return from the head and neck
What are the extubation considerations in the prone position?
- Macroglossia or upper airway edema may necessitate leaving the patient intubated after surgery until edema subsides
- Verify an air leak around the ETT or examine larynx via direct laryngoscopy before extubation in suspected patients
What can prevent corneal abrasions? What can cause corneal abrasions?
- Three-point skull fixation*, horseshoe headrest, and foam cushions allow head to be placed in a neutral position while the eyes are kept free of pressure
- Head may slip or rotate on horseshoe headrest allowing pressure to be applied over the globe and placing the patient at risk of central retinal artery thrombosis
What artery can be effected by the corneal abrasions?
central retinal artery thrombosis
What are pressure point locations in the prone position?
–Pad pressure points at elbows, knees, and ankles
–ECG leads
–Nose, eyes, face
What are protective steps for the eyes and ears?
■Closed eyelids
■Eyes protected
■Lubricate eyes +/-
■Head at level with or higher than heart
Avoid intra-abdominal pressure to __________________
decrease venous congestion
Review the parts of the prone postion protection,
What is another name for the sitting position?
“Semi-reclining”/ “Beach chair”
What is the basics of the sitting position?
■Legs elevated to level of heart
■Head flexed
What needs to be used in the sitting position?
- SCDs
What are the main advantages of the sitting position?
access to airway, reduced facial swelling, improved ventilation
What are the advantages of sitting position?
- Decreased blood loss
- Better surgical exposure
- Access to ETT, chest, extremities
- Decrease facial swelling
- Decrease intracranial pressure