E2- Positioning

Question 1

What is the most common surgical position?

Answer 1

• Supine

Arm boards must be secure if in use.

Question 2

What are initial transient physiological changes to be expected when moving from sitting to supine?

Answer 2

Heart::
* * ↑ Venous return
* ↑ Preload
* ↑ SV
* ↑ CO

Lungs ::
* ↓Tidal volume
* ↓ FRC

Question 3

Describe arm abduction positioning

Answer 3

• 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

Question 4

Describe arm adduction positioning

Answer 4

• 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

Question 5

5 Complications of the supine position

Answer 5

* 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) **

Question 6

What is the most common nerve positioning injury?

Answer 6

Brachial Plexus

Question 7

What position is this patient in?

Answer 7

• Trendelenburg (head down)

Question 8

Safety/general considerations with Trendelenburg position.

Answer 8

• 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

Question 9

Pathophysiological considerations with Trendelenburg position.

Answer 9

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

Question 10

What position is this patient in?

Answer 10

• Reverse Trendelenburg (head up)

Question 11

Safety/general considerations with Reverse Trendelenburg position.

Answer 11

• non-sliding mattress/pad to prevent patient sliding
• footrest under feet to prevent patient sliding

Question 12

Pathophysiological considerations with Reverse Trendelenburg position.

Answer 12

• 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

Question 13

Name the positions

Answer 13

• Left Picture: Beach Chair Position
• Right Picture: Full Sitting Position

Question 14

When will the patient be in the Beach chair position?

Answer 14

• Shoulder Cases

Beach chair position will have less severe hip flexion and slight leg flexion.

Question 15

Describe the set-up of the full sitting position

Answer 15

• 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

Question 16

Sitting position 5 risk

Answer 16

• 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

Question 17

Pathophysiological consideration of the sitting position?

Answer 17

Heart ::
* * Hypotension d/t ↓ venous return.
* ↓ MAP
* ↓ Cardiac Index
* ↓ Cerebral Perfusion Pressure - art tragus

Lungs ::
* Improved ventilation in non-obese patients

Question 18

What position is the patient in?

Answer 18

• Prone — with Wilson frame

Question 19

Describe the prone position.

Answer 19

• 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 !!

Question 20

Why do you not turn a prone patient’s head to one side or the other?

Answer 20

• Risk of jugular occlusion or carotid occlusion

Question 21

Risk of prone position

Answer 21

• 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

Question 22

Pathophysiological considerations for prone patients

Answer 22

• 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

Question 23

What position is the patient in?

Answer 23

• Lithotomy

Question 24

Describe the Lithotomy position

Answer 24

• 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

Question 25

Lithotomy risk

Answer 25

* 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

Question 26

For the Lithotomy Position, the_______ nerve is particularly prone to injury as it lies between the fibular head and compression from the leg support.

Answer 26

* Peroneal

Question 27

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.

Answer 27

* Lateral femoral cutaneous

Question 28

Pathophysiological considerations for the lithotomy consideration.

Answer 28

Heart :: good * ↑ Venous return, ↑ CO, and ↑ ICP * ↑ Intraabdominal pressure Lungs = bad * Displaces diaphragm cephalad * ↓ Lung compliance and ↓ tidal volume

Question 29

What position is the patient in?

Answer 29

* Lateral Decubitus Position

Question 30

Describe the Lateral Decubitus position.

Answer 30

* 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 s**hould 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**

Question 31

For right Lateral Decubitus, what side of the patient will be down?

Answer 31

* RIGHT lateral decubitus = RIGHT side down

Question 32

Safety/general considerations for the lateral decubitus position

Answer 32

* 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**

Question 33

Pathophysiological considers for the Lateral Decubitus position

Answer 33

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

Question 34

Peripheral nerve injury can be caused by what factors?

Answer 34

* Stretch * Pressure * Ischemia *Peripheral nerve injury can occur in as a little as 30 minutes.*

Question 35

Can nerve injury occur even when optimal positioning is performed?

Answer 35

* 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.*

Question 36

Which AANA standard relates to patient positioning?

Answer 36

* Standard 8: Patient Positioning

Question 37

A patient is supine with the neck extended and the head turned to the right, away from surgical site. Which positioning complication may occur?

Answer 37

* Brachial plexus nerve injury

Question 38

Shoulder braces used during Trendelenburg increases the risk of compression injury to the _______.

Answer 38

* Brachial plexus

Question 39

What position is contraindicated in a patient with an increased ICP?

Answer 39

* Trendelenburg

Question 40

If an arterial line is used for pressure monitoring in a patient placed in Reverse Trendelenburg, the transducer should be zeroed at _________.

Answer 40

* The Circle of Willis *This will represent arterial pressure at the base of the brain.*

Question 41

What position should the patient be placed in if there is a suspected cerebral air embolism?

Answer 41

* 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.

Question 42

When placing a patient in a lithotomy position, why must the legs be raised and lowered synchronously?

Answer 42

* Prevent torsion and injury to lower spine