1. Positioning in anaesthesia
Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu),
Dip. Diab. DCA, Dip. Software statistics
PhD (physio)
2. Goals
• Avoid pressure on the chest cavity
• To maintain circulation
• To prevent nerve damage
• To maintain patient’s airway
• To provide adequate exposure of the
operative site
• To provide comfort and safety to the patient
3. Positions – common
• Patient is not aware of the damage and he
cant tell that my eye is getting compressed
• supine,
• lithotomy,
• sitting,
• head-down,
• prone,
• lateral decubitus
5. Supine
• We spent most of our life like this
• Be careful
• patients with morbid obesity,
• mediastinal masses,
• poor cardiac function and
• term parturients prone to aortocaval
compression
• .
8. Supine
• prolonged contact of the back of the head
may result in alopecia
• ulnar neuropathy is the most common- males
• 0.25 % may be delayed upto 3 days
• Brachial plexus, femoral cutaneous nerves are
next common.
• Brachial or ulnar ??
9. Head rotation
putting brachial
plexus under
traction
Excess abduction of
upper limb
Forearm pronation
putting pressure on
ulnar nerve in ulnar
groove
11. RS
• cephalad movement of the abdominal contents.
• The main complications are airway obstruction
and decreased tidal volumes
• The resulting reduction in functional residual
capacity (FRC) is detrimental to gas exchange
• increase in ventilation–perfusion mismatching
and decrease in pulmonary compliance.
12. • loss of the natural lumbar lordosis
• associated with postoperative low back pain.
• The occiput, sacrum and heel are at risk of
developing pressure sores
15. Lawn Chair Position
• modification of the standard supine position
• the lower and upper halves of the body are
slightly elevated in relationship to the hips
• Better venous drainage , better muscle
relaxation
17. beach chair position
• beach chair position is associated with the
risk for cerebral underperfusion.
• Blood pressure must be maintained at a level
that guarantees a perfusion pressure of 60 to
70 mm Hg measured at the level of the
foramen magnum
19. Trendelenburg
• Central blood volume increase by 1 litre.
swelling of the face, conjunctiva, larynx, and
tongue ?? postoperative upper airway
obstruction.
• The cephalic movement of abdominal viscera
against the diaphragm also decreases
functional residual capacity and pulmonary
compliance.
20. 5 March 2017 20
Effects of Trendelenberg’ s position
• ↑ CVP
• ↑ ICP
• ↑ IOP
• ↑ myocardial work
• ↑ pulmonary venous pressure
• ↓ pulmonary compliance
• ↓ FRC
• Swelling of face, eyelids, conjunctiva & tongue
observed in long surgeries
23. Reverse Trendelenburg position(head-
up tilt)
• to facilitate upper abdominal surgery by
shifting the abdominal contents caudad.
• This position is popular because of the
growing number of laparoscopic surgeries.
• slipping on the table,
• monitoring of arterial blood pressure.
24. Reverse Trendelenburg position
• hypotension and increased risk of venous air
embolism (VAE).
• the position of the head above the heart
reduces perfusion pressure to the brain
25. Lithotomy
• This position is most often used for
• genitourinary, gynecologic, and colorectal
• Procedures.
• Hips flexed 100 deg 30-40 deg. abduction at
the hips
• . Knees 90 approx 30 deg
27. Martin and Warner have proposed a
standardized classification
• low,
standard,
• high,
• hemi,
• exaggerated,
• tilted
• Martin JT, Warner MA (Eds): Positioning in
Anesthesia and Surgery, 3rd edition. Philadelphia,
WB Saunders, 1997
32. Lithotomy
• coordinated positioning of the lower
extremities by two assistants to avoid torsion
of the lumbar spine.
• Both legs should be raised together, flexing
the hips and knees simultaneously.
• Slow removal
• Hands beware
33. lithotomy from the supine position
• Unanticipated stimulation of the carina with
bronchospasm or endobronchial intubation
may result.
• In the lithotomy position, calf compression is
almost inevitable and this predisposes to
venous thrombo embolism and compartment
syndrome ( surgery > 5 hours)
35. Lithotomy
• Lower extremity compartment syndrome is a
rare complication associated with the
lithotomy position.
• perfusion to an extremity is inadequate,
resulting in ischemia, edema
extensive rhabdomyolysis from increased
tissue pressure within a fascial compartment
36. Nerve injuries
• injury to the common peroneal nerve was
the most common lower extremity motor
neuropathy, representing 78% of nerve
injuries.
• A potential cause of the injury was the
compression of the nerve between the lateral
head of the fibula and the bar holding the
legs.
38. Exaggerated Lithotomy
• Extreme flexion of the hip
joints can cause
• neural damage by stretch
(sciatic and obturator
nerves)
• direct pressure
(compression of the
femoral nerve as it is
passes under the inguinal
ligament)
39. Hemodynamics and RS
• preload increases, transient increase in
cardiac output
• Cerebral venous and intracranial pressure in
otherwise healthy patients.
• causes the abdominal viscera to displace the
diaphragm cephalad, reducing lung
compliance and potentially resulting in a
decreased tidal volume
40. The frog-leg position
• hips and knees are flexed
• hips are externally rotated with the soles of
the feet facing each other,
• allows access to the perineum, medial thighs,
genitalia, and rectum.
• Care must be taken to minimize stress and
postoperative pain in the hips and prevent
dislocation by supporting the knees
appropriately
41. The prone or ventral decubitus
position
• used primarily for surgical access to the
posterior fossa of the skull,
• the posterior spine,
• the buttocks and
• perirectal area,
• and the lower
• extremities.
42. Prone position
Minimal neck
flexion
Face in
soft
headring
with
no
pressure
on eyes
and nose
Elbow
padded
No pressure in
axilla
Abdomen
free
anterior
flexion,
abducted
and
externally
rotated
g
e
n
i
t
a
l
n
i
p
p
l
e
43. Abdomen pressure in prone
• inferior vena caval compression,
• reduced venous return and subsequent poor
cardiac output.
• Associated pulmonary problems are caused by
an increase in transdiaphragmatic pressure
leading to reduced thoracic compliance.
44. RS – better
• An increase in FRC, changes in diaphragmatic
excursions and improved ventilation–
perfusion matching can significantly improve
oxygenation in the prone position.
• for treatment of refractory hypoxaemia and in
early ARDS
• 70–80% of patients turned prone initially
benefit from improved oxygenation
45. Prone position
• Complete obstruction of the contralateral
• vertebral blood flow with rotation of the head
>80
• Beware in old CVAs
• ‘Concorde’ position with the neck flexed and
the chin approximately one finger-breadth
from the sternum
53. The prone jackknife position
• is often used for anorectal surgery.
• is first placed prone, and all pressure
• points are padded.
• The patient is situated on the table such that
when the table is anteflexed the apex of the
inverted “V” is at the patient’s inguinal
region.
54. Knee chest position
• sigmoidoscopies or
lumbar laminectomies
Severe hypotension is
seen due to pooling of
blood in the legs
57. Watson jones ortho table
• Brachial plexus injury
– Due to > than 90* extension of the upper limb
• Lower extremity compartment syndrome
– Due to long surgeries & compression
• Pudendal nerve injury
– Due to pressure of the perineal post
68. Nerve injuries- overall
• ulnar neuropathy has been found in as many
as 26% of patients undergoing open-heart
surgery
• lower extremity neuropathy occurred in
1.5% of patients in the lithotomy position.
• The incidence of ulnar neuropathy is
estimated at 0.46% after noncardiac surgery
69. Overall mechanism of nerve injuries
• (i) stretch,
• (ii) compression,
• (iii) generalized ischaemia,
• (iv) metabolic derangement.
70. all predispose to perioperative nerve
injury
• Peripheral vascular disease,
• diabetes,
• hereditary neuropathy, and
• anatomic variation (eg, cervical rib),
75. Wedge in pregnant
• A rare complication of this positioning is
sciatic neuropathy, suggesting that time in
this position should be minimized
• Early intervention within 48 hours with EMG
studies
• no significant difference in the incidence of
ulnar neuropathy in patients undergoing
general anaesthesia, regional anaesthesia or
sedation.
77. Effects of Positioning - Obese
Patients
• Lateral:
– Well tolerated
– Correct sizing and placement of axillary roll is
important
– Ensure that pendulous abdomen does not hang
over side of OR bed
• Head-Up: (Reverse Trendelenburg/Semi-recumbent)
– Most safe
– Weight of abdominal contents unloaded from
diaphragm
– Use of well-padded footboard to prevent sliding
78. Ocular injuries
• The frequency of eye injury during anaesthesia
and surgery is very low (<0.1% of anaesthetics),
• As little as 10 min
• Corneal abrasions, periorbital,and conjunctival
edema, ocular hemorrhage,
• vitreous loss, retinal detachment,
• central retinal artery occlusion,
• ischemic optic neuropathy
79. Causes
• Patient movement,
• chemical irritation from prep solutions,
• direct trauma from face mask,
• pressure from the laryngoscopic blade,
• pressure effects on the globe from lateral
• and prone positioning, (duration )
• intraoperative hypotension, and anemia
81. Don’t Forget:
• Good positioning starts with an assessment
• Prevent surgical team members from leaning
• Arm board pads should be level with table pads
• Cushioning of all pressure points is a priority -
• Procedures longer than 2 ½ to 3 ??
• During a longer procedure, shifting the patient,
adjusting the table, or adding/removing a positioning
device
• assess extremities at regular intervals for signs of
circulatory compromise
• Documentation of the positioning process- accurate
and complete
82. Summary
• Change – check all
• Cardiac
• Respiratory
• Nerve injuries
• Pressure sores
• Visual loss
• Follow up for some days
