Positioning Flashcards
Possible complications include
Peripheral nerve injuries
Hypotension
Ventilatory compromise
Optic neuropathy
Physical injuries associated with positioning: such as
skin damage, fractures and amputation.
Can contribute to post-op complications.
Obesity Diabetes Arthritis Peripheral vascular disease, Alcohol abuse pre-existing neurological conditions
Most common surgical positions
Supine Trendelenburg Prone Lateral Decubitus LITHOTOMY Sitting
This position produces minimal circulatory effects
The supine (lying down)
FRC with supine
decreased by about 800 ml
The decrease in FRC with supine position reflect
Cephalad displacement of the diaphragm compressing the lung bases
What conditions can further decrease the FRC
This is further exacerbated by an enlarged abdomen such as with obesity, pregnancy, or ascites.
The hips and knees in supine position
are often flexed slightly with a pillow under the knees,
Hips and knees flexed in supine Facilitating
venous drainage from the lower extremities and decreasing anterior abdominal wall tension.
Heels and occiput should be
padded
For pregnant patient remember
put a wedge under the right hip of the pregnant patient in the supine position
What does the LEFT LATERAL DISPLACEMENT do
Keeps the gravid uterus from causing too much pressure on the inferior vena cava that decreases venous return to the heart further resulting to decrease in cardiac output.
If the arms can be abducted on a padded board it
must be no more than
90 degrees
Take care that there is no pressure on the
ulnar nerve at the elbow in the condylar groove.
The arms are often secured in a “papoose”
manner with a draw sheet. This effectively limits
the
anesthetist’s access to the arms.
Supine summary
Equalization of pressures throughout the arterial system;
increased right-sided filling and cardiac output
decreased heart rate and peripheral vascular resistance (PVR).
Gravity and lungs
Increases perfusion of dependent (posterior) lung segments; abdominal viscera displace diaphragm cephalad.
SV favors
dependent lung segments,
CV favors
independent (anterior) segments.
FRC decreases and may
fall below CV in older patients.
________the patient in supine position with a
head-down tilt
Trendelenburg
Trendelenburg abdominal viscera action ? can accentuate HyPOTENSION
The abdominal viscera push on the diaphragm, compressing lung bases and heart (↓SV). this can accentuate HYPOTENSION
Cardiac output also decreases in this position d/t
stimulation of baroreceptors
Trendelenburg
Cardiac output decreases in this position TRENDELEBURG
Stimulation of baroceptors
Trendelenburg ____ICP how?
In some patients, this position can increase intracranial
pressure by elevating venous pressure
_________can also be caused by decreased venous
return
Hypotension
NO longer use _____braces why?
Shoulder braces are no longer used routinely due
to possible brachial plexus injury caused by the
compression of the plexus against bony
structures of the shoulder
If shoulder braces are used they should be well
padded
If shoulder braces used positioned so they are over the not the ______or ______
acromion, the clavicle or base of the neck
CV of Trendelenburg
Activation of baroreceptors, generally causing
decreased cardiac output, peripheral vascular resistance, HR and BP.
Respiratory effects of Trendelenburg: lung capacities _______from ?
Marked decreases in lung capacities from shift of
abdominal viscera;
Respiratory effects of Trendelenburg: VQ
Increased V/Q mismatching and Respiratory atelectasis; increased likelihood of regurgitation.
Trendelenburg: NEURO
Increased ICP and decrease in CBF because of cerebral Neuro venous congestion
Trendelenburg: EYE
Increased IOP in patients with glaucoma.
Reverse Trendelenburg: Cardiac
Preload, CO, arterial pressure
preload, cardiac output and arterial pressure decrease.
Reverse Trendelenburg Baroreflexes i
Increase sympathetic tone, HR and PVR.
Reverse Trendelenburg: SV and FRC
SV requires less work; FRC increased.
Reverse Trendelenburg: NEURO
Decreased CPP and CBF
PRONE position do not
*DO NOT TUG, PULL, PUSH, HELP
Main Objective for PRONE Is
Maintain alignment of the head, neck and spinal cord with neck slightly flexed.
In prone The diaphragm is displaced _______there is
impediment of _______________
cephalad, downward descent of the diaphragm,
Prone Peak airway pressures______ and pulmonary
compliance_____
increase ; decreases
In prone, pressure on the-____and _______ lung bases
forced. This can be offset by________, which may further
inferior vena cava and aorta; cephalad
mechanical ventilation; compromise blood flow
Bolsters (“jelly rolls”)
can be placed under the patient from iliac crests to shoulders;
When using these techniques (frames) the arms can be placed ________or on_______ palongside the
patient’s head taking care to avoid pressure on the______
at the sides, ; added boards; ulnar nerves at the elbows
Be aware that prolonged time in the prone position and large fluid loads can cause_______. Evaluated______
cause swelling of the upper airway and tongue. Evaluate the face before you extubate.
Ischemic optic neuropathy, a rare but potentially
devastating complication can occur with the
prone position
What is Ischemic optic neuropathy?
An infarction of the optic nerve due to decreased
oxygen delivery by one or more small arterioles supplying the nerve
Potential causes of ION
Potential causes include: long operating times
(average 7 hours or more), large blood loss, relative
hypotension and anemia
Prone position and ION
The prone position may elevate CVP and retard the
drainage through opthalmic veins
Risk factors for ION
Patient risk factors include hypertension, diabetes, CAD,
and smoking
ION can be partial or cause complete blindness and is
not reversible
Summary PRONE CV
Pooling of blood in extremities and compression of abdominal muscles may decrease preload, cardiac output and BP.
SUMMARY Resp PRONE
Compression of abdomen and thorax decreases total lung
compliance and increases work of breathing.
Summary Neuro effects prone
Extreme head rotation may decrease cerebral venous drainage and CBF.
This position is most often used for hip, kidney, and
thoracic procedures
Lateral Decubitus
In lateral decubitus
The inferior vena cava can be compressed by the kidney
bar under the dependent iliac crest compromising blood
flow
During mechanical ventilation, the dependent lung is
relatively_______ due to compression by the
underventilated ; weight of the mediastinum and abdominal contents