Test 1: Anesthesia for Orthopedic Surgery Upper Extremity - Hip Fracture Flashcards
Preop considerations before shoulder surgery
- Baseline vital signs
- Airway
- Assess for pre-existing nerve conduction issues
- Examine pupils
What are the possible positions for shoulder surgery
- Beach chair/sitting
- Lateral decubitus
—-Secure head, neck, hips and legs—-
True or False: The ultimate responsibility with positioning lies only with the surgeon and the anesthesia provider
False
Shared responsibility
- Surgeon
- Anesthesia
- OR nurses
- PA/First assist
- Scrub tech
- Other OR personnel
What are the cardiac considerations while in sitting position?
Pooling blood in lower body decreases central blood volume.
Cardiac output and arterial BP fall despite rise in HR and SVR
What are the respiratory considerations while in sitting position?
Lung volumes and FRC increase
What are the neuro considerations while in sitting position?
Decreased CBF
What positions are common causes for venous air embolism?
-sitting
-prone
-reverse T positions
How is venous air embolism prevented?
Maintain venous pressure above 0 mmHg at the wound
Is venous air embolism more likely if the wound is above or below the heart?
Above
What are potential complications from venous air embolism?
- Pulmonary edema and reflex bronchoconstriction
- Air may reach cerebral and coronary circulation via a patent formen ovale
- Death can result from acute cardiovascular collapse and arterial hypoxemia
What is the incidence rate of patent foramen ovale?
20-30% of population
What is the treatment if venous air embolism (VAE) is suspected?
- Notify surgeon so they can prevent the further entraining of air by irrigating and applying occlusive dressing
- Discontinue N2O if used
- Bilateral compression of jugular veins
- Place patient in head-down position (to trap the air in the right atrial apex preventing entrance to the pulmonary artery)
- Withdrawing air through a previously placed right atrial catheter
- Cardiovascular collapse will need treatment with pressors
The doppler ultrasound transducer is a sensitive non-invasive indicator of a venous air embolism in the sitting patient. Where do you place the probe on the chest?
a. over the left ventricle
b. over the mediastinum
c. over the right atrium
d. over the pulmonary artery
C. over the right atrium
What is the most definitive diagnostic for identifying VAE?
TEE
What is the characteristic sound of a VAE?
Mill-wheel murmur
What does a sudden decrease in end tidal CO2 indicate?
Decreased perfusion to the lungs
What is eye protection preventing in shoulder procedures?
- Corneal abrasion
- Retinal ischemia
- Ischemic optic neuropathy
There is approximately a ______ mm Hg decrease for each centimeter difference in height between the brain and the heart.
- 0.77 mmHg decrease for every cm
In most adults placed in a beach chair position, there will be approximately a _______ cm difference (range) in height between a BP cuff located on the upper arm and the external auditory meatus, which represents the base of the brain.
- 10 to 30 cm
If the BP of the upper arm (at the level of the atrium) is 120/80 and there is a 20 cm difference to the head. What is the BP of the brain?
- 105/65 at the brain
20 cm x 0.77 = 15
SBP of the brain: 120 -15 = 105
DBP of the brain: 80 - 15 = 65
If the BP of the upper arm (at the level of the atrium) is 90/60 and there is a 30 cm difference to the head. What is the BP of the brain?
- 67/ 37 at the brain
30 cm x 0.77 = 23
SBP of the brain: 90 - 23 = 67
DBP of the brain: 60 - 23 = 37
Autoregulation maintains cerebral blood flow relatively constant between ______ and ______ mm Hg mean arterial pressure.
- 50 and 150 mmHg
When in the sitting position for a shoulder procedure, where do you want the patients blood pressure?
Intentional hypotension
When in the sitting position for a shoulder procedure, where do you place the BP cuff
Upper extremity on non-operative side
When in the sitting position for a shoulder procedure, if providing regional anesthesia, what types of blocks are most likely to be performed?
Brachial plexus block
- Interscalene
- Supraclavicular
What are the possible causes of bezold-jarisch reflex in a sitting patient and what does it result in?
R/T venous pooling and hypercontractile ventricle with decreased intraventricular volume
Results in severe hypotension and bradycardia
What are complications of brachial plexus block?
- Respiratory depression
- Hemidiaphragmatic paresis
- Horner syndrome (ptosis, miosis, anhydrosis)
- Hoarseness
- Dysphagia
Positioning for elbow procedures
- Supine
- Lateral
Cardiac considerations for lateral decubitus position
- Cardiac output remains unchanged unless venous return obstructed (e.g. kidney rest)
- Arterial BP may fall as a result of decreased vascular resistance (Right side > Left side)
Respiratory considerations in ventilated patients for lateral decubitus position
- Decreased ventilation of dependent lung (VQ mismatch)
- Increased perfusion of dependent lung
- Further decreases in dependent lung ventilation with paralysis and open chest
Respiratory considerations in spontaneously breathing patients for lateral decubitus position
- Increased ventilation of dependent lung (No VQ mismatch)
Where is the “axillary roll” placed?
Just caudad to the axilla
Avoid compression of neurovascular bundle in the dependent axilla
How do you check to ensure there is no neurovascular compromise when using an axillary roll?
Place pulse oximeter on the dependent hand and periodically check the radial pulse
How does the axillary roll compress the brachial plexus?
By displacing the head of the humerus, pressing up against the brachial plexus
Where is the upper arm placed while in lateral decubitus?
The upper arm can rest on pillows or be placed in a padded support bar (Allen arm rest)
While in lateral decubitus what can be used to keep the neck in normal alignment?
- Shea
- Pillow
- Donut
What needs to be checked on the face while in lateral decubitus?
- No pressure on the dependent eye
- The dependent ear is flat against the head
What position should the legs be in while in lateral decubitus?
- Pillow between the knees
- Lower leg should be flexed slightly
If using a tourniquet while operating on the elbow, what pressure should the tourniquet be inflated to?
~100 mmHg > SBP
If using a tourniquet while operating on the elbow, what other regional block might be considered?
Musculocutaneous nerve block
What needs to be assessed preoperatively in forearm to hand procedures?
- Preexisting nerve conduction issues
- Fracture
- Nerve impingement
- Traumatic amputation
- Typical assessment
How are forearm for hand procedures positioned?
- Supine
- Hand table
What blocks may be considered in forearm to hand procedures?
- Axillary block
- Bier block
What is the incidence of hip fractures?
1 in 50 over age 60
What is the initial hospitalization mortality of hip fractures?
~10%
What is the 1 year mortality of hip fractures?
~25-30%
Preoperative considerations for hip fracture
- Pain management (early surgery = lower pain scores)
- IVF status
- Hgb & Hct
- Central line & A line?
- Baseline VS (SpO2 on room air)
- Full stomach?
Positioning considerations for hip fracture
- Supine (on fracture table)
- Move to table after induction/intubation
Benefits of neuraxial anesthesia in hip fractures
- Decreased DVT & 1 month mortality
- Shorter length of hospital stay
- Lower incidence of delirium
- Improved postop pain control
Postop hip fracture considerations
- Pain management
- Mental status
- Blood transfusions
- ICU admission?
