E2- Positioning Flashcards
What is the most common surgical position?
- Supine
Arm boards must be secure if in use.
What are initial transient physiological changes to be expected when moving from sitting to supine?
Heart::
* * ↑ Venous return
* ↑ Preload
* ↑ SV
* ↑ CO
Lungs ::
* ↓Tidal volume
* ↓ FRC
Describe arm abduction positioning
- Arm out to the side, < 90 degrees
- Padded arm boards secured to table + pt at axilla
- arms = supine (palms up)
- Elbows = padded
- arm secured with Velcro strap
Describe arm adduction positioning
- Arm tucked alongside the body
- via draw sheet under the body and over the arm
- Hand + forearm = supine (palms up) .. OR.. neutral position (palms toward body)
- Elbows are padded
- May tuck one arm if surgeon must stand on side of patient
5 Complications of the supine position
* Backache**
*** Pressure alopecia**
* Brachial plexus / axillary nerve injury = arms > 90 degrees
* Ulnar nerve injury = hand/arm is pronated (palm down)
* Stretch injury= neck extended + head turned away (brachial plexus) **
What is the most common nerve positioning injury?
Brachial Plexus
What position is this patient in?
- Trendelenburg (head down)
Safety/general considerations with Trendelenburg position.
- non-sliding mattress/pad to prevent the patient from sliding cephalad
- Avoid using bean bags or shoulder braces
- **making mark at level of patient’s head **on the sheet =determine if patient has slid
Pathophysiological considerations with Trendelenburg position.
Heart ::
* ↑ CO, ↑ Venous Return from lower extremities
- ↑ ICP, ↑ IOP
*Edema - face, conjunctiva, larynx, tongue - ↑ Intraabdominal Presure
Lungs ::
* ↓ FRC + ↓ Pulmonary Compliance
* May need higher pressure in ventilated patients
* Risk of endobronchial intubation as abdominal contents push the carina cephalad
What position is this patient in?
- Reverse Trendelenburg (head up)
Safety/general considerations with Reverse Trendelenburg position.
- non-sliding mattress/pad to prevent patient sliding
- footrest under feet to prevent patient sliding
Pathophysiological considerations with Reverse Trendelenburg position.
- Risk of Hypotension (↓ Venous Return, Venous pooling)
- Downward displacement of abdominal contents/ diaphragm (better ventilation)
- ↓ Perfusion to brain
ART LINE @ TRAGUS !!
Opposite Trendelenburg = good heart, bad lungs, bad brain
Name the positions
- Left Picture: Beach Chair Position
- Right Picture: Full Sitting Position
When will the patient be in the Beach chair position?
- Shoulder Cases
Beach chair position will have less severe hip flexion and slight leg flexion.
Describe the set-up of the full sitting position
- Head = stabilized – taped or rigid pins
- Hips = flexed < 90 degrees
knees = slightly flexed for balance + reduce stretching of the sciatic nerve - Feet are supported – prevent sliding
* Compression stockings to maintain venous return - Keep at least two finger’s distance between the chin and sternum
Sitting position 5 risk
- Cerebral hypoperfusion and air embolism - venous sinuses»_space; pulm htn, arrythmia, arrest
- Pneumocephalus- accumulation of air in subdural + inrtraventricular space, pressure on the intracranial structure
- Quadriplegia and spinal cord infarction- hyperflexion of the neck
- Cerebral ischemia
- Peripheral nerve injuries (Sciatic nerve injury)
NEURO + sciatic
Pathophysiological consideration of the sitting position?
Heart ::
* * Hypotension d/t ↓ venous return.
* ↓ MAP
* ↓ Cardiac Index
* ↓ Cerebral Perfusion Pressure - art tragus
Lungs ::
* Improved ventilation in non-obese patients
What position is the patient in?
- Prone — with Wilson frame
Describe the prone position.
- Patient lying on stomach
- Arms = side tucked or outstretched (< 90 degrees), with flexion at elbows
- Head supported face down using —- prone pillow, horseshoe headrest, or rigid fixation
- Avoid compression of breasts, abdomen, and genitalia
- Legs = padded + slightly flexed @ knees + hips
- Compression stockings for lower extremities to prevent pooling
SPECIAL:
* Intubate supine
* EKG leads on back
* Wilson Frame !!
Why do you not turn a prone patient’s head to one side or the other?
- Risk of jugular occlusion or carotid occlusion
Risk of prone position
- Facial + airway edema
- Ulnar nerve = elbows are not padded
- Brachial plexus injury = arms > 90 degrees
- Post-op visual loss secondary to decreased perfusion/ischemia
* Eye injuries r/t head position - ETT dislodgement biggest complication, document
- Loss of monitors and IV lines
Visual loss / eye injury + lines
Pathophysiological considerations for prone patients
- Edema of face, conjunctiva, larynx, and tongue
Heart ::
* ↑ Abdominal pressure
* ↓ Venous return through compression of inferior vena cava
* ↓ CO
Lungs ::
* Improved ventilation + perfusion in the lungs d/t shift to the dependent areas
What position is the patient in?
- Lithotomy
Describe the Lithotomy position
- Patient laying supine with legs up = padded or “candy cane” stirrups
- Arms = tucked or on arm boards
- If using Trendelenburg or reverse Trendelenburg = non-sliding mattress
- Hips = flexed 80 -100 degrees
- legs = abducted 30 - 45 degrees from midline, knees flexed
- Lower extremities MUST be raised and lowered in SYNCHRONY together
- prevent torsion injury to lumbar
- Foot of the bed is lowered, mustprotect hands and fingers from crush injury
- Surgery > 2-3 hours, periodically lower the legs
Lithotomy risk
- Back pain = loss oof paraspinous muscles – same as supine
- Brachial plexus injury
- Ulnar nerve injury
* Common peroneal injury - knee flexion -
Lateral femoral cutaneous injury - inguinal + impinged
* Compartment syndrome
weird nerves + compartment
For the Lithotomy Position, the_______ nerve is particularly prone to injury as it lies between the fibular head and compression from the leg support.
- Peroneal
For the Lithotomy Position, branches of the ____________nerves often pass directly through the inguinal ligaments and can be impinged and become ischemic within the stretched ligament.
- Lateral femoral cutaneous
Pathophysiological considerations for the lithotomy consideration.
Heart :: good
* ↑ Venous return, ↑ CO, and ↑ ICP
* ↑ Intraabdominal pressure
Lungs = bad
* Displaces diaphragm cephalad
* ↓ Lung compliance and ↓ tidal volume
What position is the patient in?
- Lateral Decubitus Position
Describe the Lateral Decubitus position.
- Patient lying on non-operative (dependent) side
- requires anterior and posterior support w/ rolls or bean bags
- Adequate head support… no pressure on eyes or ears
- Neutral position
- Dependent ear should be regularly checked
- Dependent leg is slightly flexed
- Arms =front of patient + both supported and abducted** < 90 degrees**
- Axillary roll placed between chest wall and bed, caudal to axilla to prevent brachial plexus compression
- Must place padding between knees
For right Lateral Decubitus, what side of the patient will be down?
- RIGHT lateral decubitus = RIGHT side down
Safety/general considerations for the lateral decubitus position
- If bed flexed or kidney rest used, needs to be placed under iliac crest
* Inferior vena cava compression can occur - Consider proper positioning to allow the best possible expansion of the dependent lung
- Ulnar nerve injury = elbows not padded
- Brachial plexus injury = arms > 90 degrees
- ETT dislodgement; caution with use of LMA
Pathophysiological considers for the Lateral Decubitus position
Heart ::
* Venous pooling in lower extremities (use compression stockings/devices)
LUNGS ::
* V/Q mismatch due to
* inadequate ventilation to dependent lung
decreased blood flow to the nondependent lung
Peripheral nerve injury can be caused by what factors?
- Stretch
- Pressure
- Ischemia
Peripheral nerve injury can occur in as a little as 30 minutes.
Can nerve injury occur even when optimal positioning is performed?
- Yes
Overall, cases of nerve injuries have decreased, but are still a major legal cause to professional liability claims and can still occur even when optimal positioning is performed.
Which AANA standard relates to patient positioning?
- Standard 8: Patient Positioning
A patient is supine with the neck extended and the head turned to the right, away from surgical site. Which positioning complication may occur?
- Brachial plexus nerve injury
Shoulder braces used during Trendelenburg increases the risk of compression injury to the _______.
- Brachial plexus
What position is contraindicated in a patient with an increased ICP?
- Trendelenburg
If an arterial line is used for pressure monitoring in a patient placed in Reverse Trendelenburg, the transducer should be zeroed at _________.
- The Circle of Willis
This will represent arterial pressure at the base of the brain.
What position should the patient be placed in if there is a suspected cerebral air embolism?
- The patient should be positioned in a head down/Trendelenburg and left lateral decubitus position (Durant position).
- This aims to trap air in the right atrium and ventricle, thus minimizing the entry of air emboli into the right ventricular and pulmonary artery.
When placing a patient in a lithotomy position, why must the legs be raised and lowered synchronously?
- Prevent torsion and injury to lower spine
