Different positioning in neurosurgical procedures with the aim to provide best surgical acess and decrease patient related risk.

1. PRESENTER – DR. SAIKAT MITRA
MODERATOR – DR. SHOBHA
PUROHIT
SMS MEDICAL COLLEGE, JAIPUR

2. INTRODUCTION
 Aim of optimal positioning is to provide best surgical access & ↓potential risk to
the patient.
 Safe positioning requires planning and good communication between
anaesthetist and surgeon.
 Skilled personnel are required at the beginning & end of surgical procedure to
facilitate safe positioning.
 Knowledge of physiological changes associated with positioning can help predict
potential problems.
 All equipments should be secured and rechecked after every change in position.
 Head-up posturing (150 - 200) to improve cerebral venous drainage.
 Many complications do not reveal themselves for up to several days after surgery.

3. POSITIONING AIDS/ SUPPORTS
 Pin (“Mayfield”) head holder
 Radiolucent pin head holder
 Horseshoe head rest
 Foam head support (e.g., Voss, O.S.I., Prone-View)
 Vacuum mattress (“bean bag”)
 Wilson-type frame
 Andrews (“hinder binder”)-type frame
 Relton-Hall (four-poster) frame

4. Mayfield head holder
Radiolucent pin head holder
Vacuum mattressHorseshoe head restFoam head support

5. FRAMES
 Spinal surgery frames optimizes venous return.
 ↑ risk of air embolism.
Relton-Hall (four-poster)frameWilson-type frame

6. POSITIONS
 Supine
 Lateral (Park bench)
 Semi-lateral (Jannetta)
 Prone
 Sitting

8. INTRODUCTION
 Commonest position; also known as ‘dorsal decubitus position’.
 Used for cranial procedures, carotid end-arterectomies & anterior
approaches to cervical and lumbar spine.
 Haemodynamic reserve best maintained (as entire body is close to the
heart level).
 Variations: a) Lawn chair position, b) Frog-leg position, c) Trendelenburg
& d) Reverse Trendelenburg position.
 As compensatory mechanisms are blunted by anaesthesia →
Trendelenburg or Reverse Trendelenburg positions cause significant
cardiovascular alterations.

9. PRESSURE POINTS

10. ARM POSITION
 May be abducted or adducted (tucked).
 Abduction limited < 900 to minimize brachial plexus injury by caudad
pressure in axilla from humerus head.
 Hand and forearm are kept supinated or in neutral position with palm
toward body to reduce external pressure on spiral groove of humerus and
ulnar nerve.
 When arms are adducted, they are usually held alongside the body with a
“draw sheet” that passes under the body, over the arm, and is then tucked
directly under the torso (not the mattress).
 Elbows and any protruding objects (i.v. fluid lines and stopcocks) are
padded.

11. ARM POSITION
Arm position using the arm board.
Abduction of arm is limited to < 900. Arm
is supinated and elbow is padded.
Arm tucked at patient side and is in
neutral position with palm to hip. Elbow
is padded and arm is well supported by
the mattress.

13. LAWN CHAIR POSITION
 Head-up posture accomplished by adjusting operating table to a
chaise lounge (lawn chair) position.
 Advantages:
 Promotes cerebral venous drainage
 Decreases stress on back, hips and knees.
 Venous drainage from lower extremity improves (legs are slightly
above heart level).
FLEXION + PILLOW UNDER KNEES + SLIGHT REV. TRENDELENBERG

14. LAWN CHAIR POSITION

15. TRENDELENBURG POSITION
 Associated with tilting a supine patient head down.
 Often used to increase venous return during hypotension.
 Named after 19th century German surgeon – Friedrich Trendelenburg.
Trendelenburg position and reverse Trendelenburg position

16. HARMFUL EFFECTS
 ↑ CVP, ICP, IOP.
 Respiratory system –
 Abdominal viscera moves cephalad against diaphragm → ↓FRC &
pulmonary compliance → ↑ V/P mismatch.
 CVS –
 ↑ VR → ↑ C.O.
 Central redistribution of blood may lead to volume overload in the failing
heart.
 Stomach lies above glottis → ↑ Aspiration.
 Prolonged head-down → lead to swelling of face, conjunctiva, larynx &
tongue → ↑ postoperative upper airway obstruction.

17. PRECAUTIONS
A. Extra-care to prevent from slipping cephalad on the surgical table due to
effect of gravity.
 Techniques –
1. Antiskid bedding
2. Knee flexion
3. Shoulder braces
4. Beanbag cradling &
5. Padded cross-torso straps.
B. To avoid compression of brachial plexus by torso against shoulder girdle.
 Shoulder braces & beanbag pads → ↑ risk of injury to upper & middle
trunk of brachial plexus.
C. Due to ↑ risk of upper airway obstruction → air leak test or visualizing
larynx before extubation must be carried out.

18. REVERSE TRENDELENBURG POSITION
 Also known as ‘head-up tilt’.
 Precautions -
 Preventing the patients from slipping on the table.
 Frequent monitoring of arterial blood pressure → hypotension may
result from ↓ VR.
 Head is positioned above heart → ↓ perfusion pressure to brain.
 Complications –
1. Hypotension
2. ↑Venous air embolism

19. HEAD DURING SUPINE POSITION
 Neutral or rotated → frontal, temporal or parietal access.
 Neutral → Bifrontal craniotomy and transsphenoidal approach
to pituitary.
 Flexion → interhemispheric approach to lateral or third
ventricle.
 Slight extension → subfrontal approach.

20. PRECAUTIONS
 Extremes of head rotation impairs jugular venous drainage →
shoulder roll attenuate this problem.
 Extreme flexion causes kinking of ET tube → ↑airway pressures
(keep a distance of 1 or 2 finger breadths between chin & chest
during flexion).
 Flexion + reverse Trendelenburg position →↑risk of VAE {esp. in
bifrontal craniotomy which traverses SSS}

21. COMPLICATIONS OF SUPINE
POSITION
1. Pressure alopecia -
 Cause –
Ischemia of hair follicles due to prolonged head immobilization with
its full weight falling on a limited area (usually occiput).
 Precautions –
 Lumps such as those caused by monitoring cable connectors should
not be placed under the head.
 Prevention of hypothermia and hypotension during surgery.
 Ample cushioning of head & periodic rotation of head to
redistribute the weight.

22. COMPLICATIONS
2. Backache -
 Cause –
Normal lumbar lordotic curvature is lost during general anaesthesia with
muscle relaxation due to their effects on tone of paraspinous muscles.
 Precautions –
 Patients with extensive kyphosis, scoliosis or h/o back pain → extra
padding of spine/slight flexion at hip and knee.
3. Peripheral nerve injury –
 Ulnar neuropathy is most common.
4. ↑ risk of aspiration of gastric contents.

23. PERIPHERAL NERVE INJURY
 As per ASA Closed Claims database (1970 – 2010):–
 Ulnar neuropathy (21%)
 Brachial plexus (20%)
 Spinal cord (19%)
 Lumbosacral nerve roots or cord (17%)
 Ulnar neuropathy –
 Classic site of injury → exposed ulnar groove behind medial epicondyle of
humerus.
 Here nerve is exposed to both direct trauma from sides of operating table and
indirect trauma from stretch.
 Precaution - Pronation makes ulnar nerve very vulnerable, while supination
keeps it in a more protected position.

24. BRACHIAL PLEXUS INJURY
 Brachial plexus (primarily C8
and T1 nerve roots)
susceptible to injury
because:-
 Long superficial course via
axilla with 2 points of fixation
- cervical vertebrae and
axillary fascia.
 Lies in close proximity to
relatively fixed first rib,
clavicle and humerus and get
compressed between these
structures.
 Precautions –
Arm abduction limited < 900
Avoid shoulder braces
Head in midline

26. INTRODUCTION
 Used for access to posterior parietal lobes, occipital lobes and lateral
posterior fossa, including tumors at CP angle and vertebral/basilar arteries
aneurysms.
 Patient rests on non-operative side; balanced with anterior and posterior
support (bedding rolls or deflatable beanbag) with flexed dependent leg.

27. ARM POSITION
 Arms are kept in front of the patient.
 Dependent arm rests on a padded arm board perpendicular to the
torso.
 Non-dependent arm is supported over folded bedding or suspended
with armrest or foam cradle.
 Neither arm should be abducted > 900.
 Axillary roll is placed between chest wall and bed just caudal to
dependent axilla to prevent compression of dependent
neurovascular bundle (should never be placed in the axilla).

28. Axillary roll is placed well away from
axilla to prevent compression of axillary
artery and brachial plexus.

29. POSTIONING
 Head must be in neutral position to prevent excessive lateral rotation of
neck and stretch injuries to brachial plexus → this requires additional
head support.
 Dependent ear should be checked to avoid folding and undue pressure.
 Eyes should be securely taped before repositioning.
 Dependent eye must be checked for external compression frequently.
 A pillow or other padding is placed between knees with dependent leg
flexed to minimize excessive pressure on bony prominences & stretch
of lower extremity nerves.

30. Picture showing placement of arms and head.
Additional padding is under headrest to ensure
alignment of head with spine. Headrest is kept
away from dependent eye.

31. PRECAUTIONS
 Pulse should be monitored in dependent arm to detect early compression
of axillary neurovascular structures.
Vascular compression and venous engorgement in the dependent arm may
affect pulse oximetry reading.
↓SpO2 is an early warning sign of compromised circulation.
 Hypotension measured in dependent arm may be due to axillary arterial
compression.
 When kidney rest is used, it must be properly placed under dependent
iliac crest to prevent inadvertent compression of IVC.

32. PHYSIOLOGICAL CHANGES
 Respiratory system:-
 Non-dependent lung → well ventilated, poorly perfused.
&
 Dependent lung → well perfused, poorly ventilated (due to lateral
weight of mediatinum & disproportionate cephalad displacement of
abdominal contents)
↑ V/Q mismatch
 Cardiovascular system:-
 Minimal decrease in MAP; HR unchanged.

33. POTENTIAL PRESSURE POINTS

34. PARK-BENCH OR
THREE QUARTER PRONE POSITION
 Modification of lateral position.
 Provides better access to posterior fossa (compared to lateral position).
 Placing patient sufficiently superiorly on operating table such that
dependent arm hangs over edge of table & secured with a sling.
 Trunk is rotated 15⁰ from lateral position into semiprone position &
supported with pillows.
 Lower extremities should be slightly flexed and pillow placed between legs.
 Head is flexed at neck and then rotated to look toward the floor (120⁰ from
vertical & laterally flexed 20⁰ ).

37. SEMILATERAL POSITION
 Named after the neurosurgeon who popularized its use for
microvascular decompression of 5th cranial nerve.
 Used for petrosal, retromastoid & U/L frontotemporal approaches.
 Achieved by lateral tilting of table 100 to 200 combined with a
generous shoulder roll.
 Extreme head rotation should be avoided (to prevent compression
of contralateral jugular vein by the chin).
 Excessive traction on shoulder should be avoided.

39. INTRODUCTION
 Also known as ‘ventral decubitus position’.
 Used for spinal cord, occipital lobe, craniosynostosis & posterior
fossa procedures.
 Physiological changes:-
 If legs are in plane with torso → haemodynamic reserve is well
maintained.
 Pulmonary function is superior to supine or lateral decubitus
positions if the patient is properly positioned with no abdominal
pressure.

40. 1
• When general anaesthesia is planned, all intravenous
accesses are obtained & trolley is kept parallel and
adjacent to operating table.
2
• Trachea is first intubated on the stretcher.
3
• ETT is well secured to prevent dislodgement and loosening
of tape due to drainage of saliva when prone.
• Antisialogogue (glycopyrrolate) and adhesive (benzoin) may
reduce loosening of tape.
POSITIONING

41. 4
• With the help of entire operating room staff, patient is
turned prone onto the surgical table.
5
• Neck is kept in line with spine during proning & arms of
the patient kept alongside the body.
6
• If cervical spine is stable, anaesthetist manage head &
coordinate turn; if unstable  neurosurgeon.
POSITIONING

42. 7
• Disconnecting BP cuffs, arterial and venous lines
present on outside arm that rotates furthest is
recommended to avoid dislodgment.
8
• Pulse oximetry can usually be maintained if applied
to the inside arm.
9
• Full monitoring should be reinstituted as rapidly as
possible.
POSITIONING

43. POSITIONING
10
• ET tube position and adequate ventilation
immediately reassessed after the move.
11
• Legs should be padded and flexed slightly at the
knees and hips.
12
• Head may be supported facedown with its weight
borne by the bony structures or turned to the side.

44. ARMS POSITION
 Both arms may be kept along the patient’s sides and tucked in
neutral position or placed in the “stick-em up” position.
 In ‘stick-em up’ position, arms should not be abducted > 90⁰ &
elbows should not be extended > 90⁰ (90-90 position) to prevent
excessive stretching of brachial plexus, especially in patients with
head turned.
 Elbow should be anterior to the shoulder to prevent wrapping of
brachial plexus around head of humerus.
 Extra padding under the elbow may be needed to prevent
compression of ulnar nerve.

45. Prone position with Wilson frame

46. HEAD POSITION
 Head may be turned laterally, if neck mobility is adequate.
 Patients with cervical arthritis or cerebrovascular disease → lateral
rotation of neck may ↓carotid or vertebral arterial blood flow or
jugular venous drainage.
 Head is kept in neutral position (most common) using → a) Surgical
pillow, b) Horseshoe headrest or c) Mayfield head pins.
 Disadvantage with pillows → face is not always visible making eye
checks more difficult.
 Mirror systems are available to facilitate intermittent visual
confirmation that eyes are not compressed.

47.  Horseshoe headrest supports only forehead and malar regions and allows
excellent access to the airway.
 Mayfield rigid pins firmly hold the head in one position without any direct
pressure on face & allow access to the airway.
HEAD POSITION
Mirror system for prone position Prone position with horseshoe adapter

48. TAKE CARE OF ABDOMEN & THORAX
 Aim of posterior spinal surgery - ↓venous pressure to minimize bleeding
and facilitate surgical exposure.
 External pressure on abdomen → ↑intra-abdominal and intra-thoracic
pressures.
 ↑Abdominal pressure → ↑venous pressure of valveless abdominal & spine
vessels (including epidural veins) and causes compression of IVC →↓VR,
cardiac output.
 External pressure on abdomen pushes diaphragm cephalad → ↓FRC &
pulmonary compliance; ↑PIP.
 Firm rolls or bolsters placed along each side from clavicle to iliac crest to
support the torso → ↓abdominal, thoracic pressures.

49. PRESSURE POINTS

50. PRECAUTIONS
 Use of wire-reinforced ET tube to avoid kinking and obstruction as it
exits patient’s mouth during prone position.
 Dependent eye must be frequently checked for external
compression.
 Abdomen should hang relatively free and move with respiration.
 Breasts should be placed medial to gel bolsters.
 Lower portion of each roll or bolster must be placed under its
respective iliac crest to prevent pressure injury to genitalia and
femoral vasculature.

51.  Prevention of patient movement when head is held in rigid pins →
skidding out of pins can result in scalp lacerations/cervical spine injury.
 Horseshoe and pin headrests attach to adjustable articulating supports
→ any slippage or failure of this bracketing device may lead to
complications due to sudden dropping of head.
 Face must be periodically checked to ensure → weight is borne only by
bony structures, airway is uncompromised and no pressure on the eyes.
PRECAUTIONS

52.  Modification of prone position.
 Used for cervical spine & posterior fossa procedures.
 Neck flexion, reverse Trendelenburg, arms tucked alongside to trunk &
elevation of legs → this orientation brings surgical field to a horizontal position.
 Complication – 1) necrosis of chin & 2) obstruction of cerebral venous outflow.
THE CONCORDE POSITION

53. 1. Postoperative vision loss (POVL) –
Retinal ischemia Ischemic optic neuropathy (ION) (more common)
COMPLICATIONS
Blindness
Cause - Orbital compression causing central
retinal vessel occlusion.
Precaution - must be intermittently confirmed
(every 15 min) & after any surgery-related
head or neck movement that eyes are not
impinged
Cause –
↓BP, ↓hematocrit, lengthy surgical
procedures, ↑i.v. fluid administration,
poor collateralization or absence of
autoregulation of vasculature of optic
nerve head, small and anatomically
“crowded” optic nerve head, impaired
cerebral venous drainage, ↑IOP.

54. 2. Macroglossia –
 Flexion of neck frequently required to facilitate surgical access → ↓AP
dimension of hypopharynx → compression ischemia of tongue base, soft
palate, posterior wall of pharynx occur in presence of foreign bodies (ETT,
esophageal stethoscope, oral airway).
 Edema accumulates after reperfusion of ischemic tissue → Macroglossia
→ post-extubation airway obstruction.
 Swollen tongue may protrude between and trap by teeth during
prolonged prone procedure.
 Rolled gauze bite block may be used instead of oral airway.
COMPLICATIONS

56. INTRODUCTION
 Used for posterior cervical spine and posterior fossa surgeries.
 Infrequently used.
 Advantages –
 Excellent surgical exposure
 Drier field
 ↓Perioperative blood loss
 Superior access to the airway
 ↓Facial swelling
 Improves ventilation
 Can see face during cranial nerve stimulation

57. PHYSIOLOGY
 Cardiovascular system:-
↓ VR, Stroke volume, Cardiac output, Cardiac index
 MAP – unchanged
 ↑ SVR, PVR
 Respiratory system:-
 FRC, VC improves
 V/P mistmatch (hypoperfusion of upper lung)
 Other systems:-
 ↓RBF, CBF

58. POSITIONING
 More commonly patient positioned in modified recumbent position.
 Head may be fixed in Mayfield head pins.
 Head holder should be attached to back portion of the table, rather
than to the thigh or leg portions → makes lowering of head and
closed chest massage if necessary, easier.
 Arms must be supported (due to gravitational pull) to the point of
slight elevation of shoulders to avoid traction on shoulder muscles
and neurovascular structures.

59.  Legs should be kept as high as possible (usually with pillows under
knees) to promote venous return.
 Knees are slightly flexed for balance and to reduce stretching of
sciatic nerve.
 Feet are supported and padded.
 Elastic stockings and active leg compression devices also help to
maintain venous return.
POSITIONING

60. Patient is typically semi-
recumbent rather than sitting.
A –
The head-holder support is
correctly positioned so that
the head can be lowered
without the necessity to first
detach the head holder.
B –
This configuration with the
support attached to the
thigh portion of the table,
should be avoided.

61. PRESSURE POINTS

62. CARE OF HEAD & NECK
 Excessive cervical flexion may occur with head fixed in pins –
 Impede both arterial and venous blood flow →
hypoperfusion or venous congestion of brain.
 Impede normal respiratory excursion.
 Obstruct ETT and place significant pressure on tongue →
leading to macroglossia.

63.  Careful vigilance of BP.
 MAP should be corrected to head level → zeroing arterial pressure
transducer at interaural plane/skull base (CPP maintenance become
easier).
 If manual BP cuff is used → correction (a column of water 32 cm high
exerts a pressure of 25 mmHg) for hydrostatic difference between arm
and operative field should be applied.
 Excessive flexion of knees towards chest should be avoided → prevent
abdominal compression,lower extremity ischemia and sciatic nerve
injury.
PRECAUTIONS

64.  Maintaining at least 2 fingers’ distance between mandible and sternum
is recommended.
 Patients should not be positioned at the extreme of their range of
motion.
 Extra caution with neck flexion is advised if TEE is used for air embolism
monitoring (as esophageal probe lies between flexed spine and airway
with ETT → compression of laryngeal structures and tongue).
 Screening contrast echocardiography to investigate the patency of the
inter-atrial septum is performed before considering sitting position.
PRECAUTIONS

65. COMPLICATIONS
1. Cardiovascular instability
2. Venous air embolism
3. Paradoxical air embolism
4. Pneumocephalus
5. Macroglossia
6. Quadriplegia

66. ANY
QUESTIONS??