6901 ortho Flashcards
Podiatry is limited to study, diagnosis, and treatment of problems of the?
foot, ankle, and lower leg
Ortho surgery involves procedures on what 4 things?
bones, joints, muscle, and related soft tissue
Some implications of RA for anesthetists?
synovitis of cervical spine, TMJ, larynx, and pulmonary system; deposition of rheumatoid nodules causes inflammation of intervertebral discs and atlanto occipital subluxation
If RA pt has limited TMJ opening use what intubation technique?
awake fiberoptic
2 s/s which indicate narrowing and fixation of glottic opening d/t cricoarytenoid arthritis?
hoarseness, inspiratory stridor
9 pulmonary lesions in RA pts?
pleural effusion, intrapulmonary nodules, rheumatoid pneumocoinosis, interstitial lung disease, vasculitis, obliterative bronchitis, upper lobe fibrosis, pulmonary infections, bronchogenic carcinoma
Very prominent physical symptom in RA pt?
swanned fingers
Difference between RA and OA?
RA is inflammatory disease of synovial membrane, which becomes thickened and there is BONE erosion; OA is where cartilages of articulating surfaces are eroded by disease or wear and tear and cartilage thins out and it is bone on bone
In 3 words what is ankylosing spondylitis?
chronic inflammatory process
Primary locus in ankylosing spondylitis?
spinal column
2 cardiac and 1 pulmonary association with ankylosing spondylitis?
conduction delays, valve lesions; restrictive lung disease
Huge issue with AS patients and intubation?
cervical spine mobility and TMJ opening
4 anesthetic considerations for pts with OA?
NSAID use, cortisone injections, activity levels, and comorbidities
Anesthetic selection in OA/RA/AS patients should consider what 5 things?
length of surgery, position of surgery, body habitus, general health, pt acceptance
The bladder inside the pneumatic tourniquet should cover what % of the extremity?
50%
Tourniquet use should not exceed how many minutes?
120
Cuff overlap of the tourniquet should overlap away from what?
neurovascular bundle
Exsanguination is done with? And what is exsanguination?
esmark; chasing the blood out of the extremity
How long does it take for tourniquets to abolish SSEPs?
30 minutes
Neurapraxia (loss of nerve function) occurs after how many minutes?
120
Where does nerve injury usually occur in relation to the tourniquet?
edge of tourniquet
Burning aching pain is d/t activation of what fibers?
c fibers
Tingling, pins, and needles pain is due to activation of what fibers?
a-delta fibers
Cellular hypoxia (tourniquet) occurs after how many minutes?
2; and acidosis occurs
What happens to creatinine values with tourniquet pain?
decrease
Endothelial capillary leak occurs after how long with use of tourniquet?
2 hours
How much blood does tourniquet release cause to be pushed in to systemic circulation?
300-500 mL
What pressures increase d/t tourniquet inflation?
systemic and pulmonary
What happens to the core temp when the cuff is deflated?
fall in core temp; is usually transient but if temp is low to begin with it might not rebound
What acid base disorder occurs after deflation of tourniquet?
metabolic acidosis
What happens to MVO2/MV after tourniquet deflation?
decreases
What happens to ETCO2 after tourniquet deflation?
transient increase
What happens to systemic and pulmonary pressures after tourniquette deflation?
transient decrease
Nerve damage reliably occurs after how many hours of tourniquet inflation?
4 hours
After 3 hours of tourniquet time, muscle power is reduced for how long?
full week
How long does it take for physiologic effects of tourniquet deflation to resolve after one hour of T time?
20 min
Most commonly used drug for IV regional anesthesia?
lidocaine
Example of dilute solution and concentrated solution of lidocaine?
dilute: 50 mL of 0.5% lido; concentrated: 12-15 mL 2% lido
What type of anesthesia is a bier block?
IV regional
3 indications for bier block?
short operative procedures for extremities, pain therapy, treatment of hyperhidrosis
LA concentration and amt for bier block?
12-15 mL of 2% lidocaine for upper extremities or 30-40 mL of 0.5% lido
Relative contraindications to bier block?
crush injuries, inability to access peripheral veins, infections, compound fractures, hx of allergy to LA, severe PVD, AV shunts, hepatic insuffiency, disrupted integrity of venous system, sickle cell disease
Some surgeries bier blocks are good for?
wrist or hand ganglionectomy, carpal tunnel release, dupuytren contractures, reduction of fractures and others
The duration of anesthesia for a bier block depends on?
the length of time the tourniquet is inflated
Typically discomfort from the tourniquet for a bier block occurs after how many minutes, which precludes its use for longer procedures?
30-45
2 disadvantages of bier blocks besides duration?
incomplete muscle relaxation and lack of post op pain relief
In a bier block, what area is anesthetized?
entire area beneath the tourniquet (and pick the most distal vein)
% lido used for bier block?
0.25-2%
catheter size for bier block?
18-20
In a bier block, where do you want the IV not used for the block?
on other arm
This med can prevent the potential CNS toxicity should the level of LA in a bier block raise?
benzo
For a bier block, how do you place the double pneumatic tourniquet?
on a padding layer of soft cloth with the proximal cuff high on the upper arm
Steps for bier block?
1) insert IV on contralat arm 2) place pneumatic tourniquet 3) insert IV as distally as possible 4) elevate arm for 1-2 min and wrap esmark bandage 5) while axillary artery is distally occluded, distal cuff (red inflated), inflate proximal (blue) cuff, deflate distal cuff 6) inject LA
How do you wrap the esmark bandage in a bier block?
spirally from the hand to the distal cuff of the double tourniquet
What is the point of the esmarch bandage?
exsanguinate the arm
Cuff pressure for bier block should be how much above SBP?
100 mm Hg
How fast do you inject the LA for bier block?
slowly
After injecting LA for bier block, what do you do?
lower the arm and remove IV from cannulated arm
Volume of LA injected for bier block depends on?
size of arm being anesthetized and concentration of anesthetic solution
Maximal dose of LA for bier block?
3mg/kg
Order of deflating cuffs in bier block?
distal cuff first then proximal cuff 25-30 min after beginning anesthesia
For IVRA what is used more commonly- small volume, larger concentration or large volume of dilute solution?
small volume, larger concentration
This LA is associated with formation of methemoglobin, but has less systemic and CNS side effects?
prilocaine
Anesthesia develops w/in how many min with bier block?
5 minutes
In a bier block, progressive numbness and complete insensitivity are followed by?
patchy decolorization of the skin and motor paralysis
Deflation of the wrong cuff in a bier block results in?
rapid loss of anesthesia and risk of systemic local toxicity
How do you check the pressure in the distal cuff for a bier block?
squeeze cuff and document oscillations on manometer
When the pt starts complaining of discomfort during a bier block, what can you do?
inflate distal cuff and deflate proximal. it provides immediate relief and the pt gets 15-30 more min of comfort
Which tourniquet should never be released before inflation of the other cuff?
proximal; distal
To prevent engorgement of the extremity in a bier block what can you do?
digital pressure on axillary artery, elevate arm, make sure there is no pulse
The proximal cuff for a bier block is near what?
axilla
At the end of a bier block, deflate the tourniquet for how long and then reinflate for how long to avoid risk of LA
10 sec; 2 min (1 min she says)
The surgeon should do what before release of tourniquet with bier block to prevent sudden oncoming pain?
infiltrate local anesthesia
4 complications of IVRA? Most common?
systemic toxicity, hematoma, engorgement, ecchymosis and SQ hemorrhage; systemic toxicity
Bier block: if surgery is finished w/in how many min after injection of LA what should you do to avoid systemic toxicity?
gradually release tourniquet w 2 min intervals between deflations
Engorgement as a complication of bier block can happen in pts with what health prob?
arteriosclerosis
Ensure that arterial pulse is absent in bier block to prevent?
engorgement
In upright position, ventilation and perfusion goes where?
perfusion to bottom of lungs and ventilation to top
Zone 1 is what part of lungs and Zone 2 is what part?
1: top; 3: bottom
In lateral position, perfusion and ventilation go to which part of lung?
perfusion goes to bottom lung and ventilation to top lung
What is hypoxic pulmonary vasoconstriction?
when pulmonary arterioles are exposed to alveoli with little O2 in them, they vasoconstrict and divert blood to alveoli where there is a closer VQ match
3 risks of injury in beach chair position?
potential for cervical neck injury d/t dislogement of head from holder, inadvertent extubation, brachial plexus injury on opposite side
4 advantages of beach chair position?
reduced rate of brachial plexus injuries, better resp mechanics, excellent access to shoulder, weight of arm distracts shoulder joint
What blunts the compensatory mechanisms in beach chair position?
volatile anesthetics
CPP decreases how much in beach chair?
15%
What happens to CVP, MAP, PAP, CO, PVR, and TPR in beach chair?
all but PVR and TPR decrease and they increase
What happens to venous return in beach chair?
can be hindered
Cerebral autoregulation is hindered with?
HTN
The distance between the arm cuff and the auditory meatus is how many cm and represents that much of a gradient between the BP in the brain versus the arm?
15 cm
There is a ___ mm Hg change in BP for every ___ cm or mm decrement in BP for each cm distance?
1; 1.25; 0.77
5 risk factors for vision loss after spine surgery in prone position?
atherosclerosis, CV disease, excessive blood loss, excessive crystalloid admin, excessive surgical length
Presentation of post op prone vision loss after spine surgery?
immediate post op vision loss
3 eye complications after prone surgery for spine surgery?
cortical blindness, central retinal artery occlusion, ischemic optic neuropathy
This occurs from major insult to vascular structures of the eye?
cortical blindness
Findings from cortical blindness?
visual field disturbances with normal retinal exam
Central retinal artery occlusion typically occurs from what 3 things?
direct pressure on globe, thrombosis, increased IOP
Findings in central retinal artery occlusion?
unilateral vision loss with periorbital edema. retina looks pale, ischemic, with pathgenomic cherry red spot at macula
10 suggestions for preventing POVL?
avoid direct pressure on globes, avoid periop hypotension, avoid periop anemia, consider 10 degrees of reverse Tburg during prone, lower transfusion threshold to keep hct >30% in at risk pts, avoid infusions of large amts of crystalloid, consider staging long spinal surgeries (>8 hours), maintain MAP at pt’s baseline, avoid changes in any perfusion related meds shortly before surgery, perform post op vision exam as soon as possible in at risk pts
At risk pt for POVL is (4)
preexisting CV disease or metabolic disease, prolonged surgery in prone, increased blood loss expected
4 benefits of arthroscopy?
less blood loss, reduced post op pain, shorter or no hospitalization, shorter rehab course
Definition of arthroscopy?
examination and treatment of joint space with endoscope
What is arthroplasty?
total joint replacement
3 goals of arthroplasty?
pain relief, stability, deformity correction
What is the blood loss and over how long in knee arthroplasty?
up to 2 U over next 24 hours usually in drain
Most frequent arthroplasty?
knee
During component insertion for TKA what 3 consequences can occur?
HTN, hypoxia, CV collapse
Possible causes of complications during component insertion for TKA?
MMA cement, fat embolism, air embolism, marrow embolism, thromboembolism
What does MMA cement do to PVR, PCMP, SVR, CO, BP?
increases PVR, PCMP; decreases SVR, CO, and systemic BP
Since there is a high incidence of DVTs post op for TKA, they get either _______ or _______ post op?
LMWH, coumadin
Incidence of PE in TKA is?
1-5%
2 positions THA can be done in?
lateral decubitus, anterior
What 2 bones are richly perfused and make blood loss likely in THA?
femur, acetabulum
4 special considerations for THA?
MMA, blood loss can exceed 6 U, typically older with comorbidities, redos at MVAMC get a line and foley
What leads to hardening and expansion of MMA cement?
exothermic reaction
MMA can cause intramedullary HTN and result in embolization of what 4 things?
fat, air, bone, cement
Bone cement implantation syndrome 5 s/s?
hypoxia, hypotension, arrhythmias, pul HTN, decreased CO
Bone cement implantation syndrome usually occurs when?
femoral component placed
5 things to do to reduce MMA risk?
increase FiO2 prior to cementing, maintain euvolemia at time cement is ab to be placed, vent distal femur, high pressure lavage of femur shaft to remove debris, use of uncemented femoral components for hips
5 ways to reduce blood loss?
cell saver, autologous blood, induced hypotension, normothermia, spinal/epidural anesthetics
Clotting cascade does not work if temp is
35
What type of blood loss occurs in upper extremity arthroplasty?
more blood loss
3 special considerations about scoliosis surgery?
typically a/p surgery, requires thoracotomy to access thoracic spine, may have some restrictive lung disease d/t progress of disease
What is scoliosis?
lateral deviation in frontal plane associated with rotation
This type of bed frame supports the hip and thorax, some weight on elbows?
Relton adjustable pedestal frame
This frame is convex saddle frame and adjustable in width and length?
wilson frame
This frame is when only thorax is touching the bed and weight is borne by the knees. pad comes across butt
Andrews frame
Prob w andrews frame and tarcoff frame?
getting venous return in to systemic circulation
Good type of anesthesia for foot and ankle surgery?
regional
5 nerves which supply sensation to the foot?
superficial peroneal nerve, deep peroneal nerve, saphenous nerve, sural nerve, posterior tibial nerve
This ankle nerve is a branch of the common peroneal nerve. It descends toward the ankle in lateral compartment and enters the ankle just lateral to extensor digitorum. it provides cutaneous sensation to dorsum of foot and 5 toes. is most constantly located lateral to extensor digitorum longus at level of lateral malleolus superficially
superficial peroneal nerve
This ankle nerve runs in anterior leg as continuation of common peroneal nerve. innervates toe extensors, enters ankle between flexor hallus longus and extansor detorus longer tendons. provides sensation to medial half of dorsal foot, esp 1st and 2nd digits. has constant location just lateral to flexor hallus longus at level of medial malleolus. anterior tibial artery lies between this nerve and tendon
deep peroneal nerve
This ankle nerve is the terminal branch of femoral nerve. supplies superficial sensation to anterior medial foot and is most constantly located to just anterior to medial maleolus
saphenous nerve
Only nerve of foot not part of sciatic system?
saphenous nerve
This ankle nerve is a continuation of tibial nerve and enters foot between achilles tendon and lateral malleolus to provide sensation to lateral foot
sural nerve
This ankle nerve is a direct continuation of tibial nerve and it enters the foot of the posterior medial malleolus branching in to 2 diff branches. constantly located behind posterior tibial artery at level of medial malleolus and is sensory to heal, medial sole, and part of lateral sole of foot
posterior tibial nerve
This muscle moves your big toe?
extensor digitorum longus tendon
6 characteristics of hip fracture surgery?
typically elderly, typically on call/after hours, multiple comorbidities, blood loss thru all operative stages, lateral position, regional anesthesia is limited by pt comorbidities and conditions
Hip fracture surgery has a high incidence of post op complications. What are 4 risk factors for post op complications?
poor ASA, urgency of procedure, extent of procedure, duration of procedure
Major complication of ORIF of hip?
fat embolism
Fat embolism occurs in what % of femur fractures?
10-20%
When does fat embolism present after surgery?
within 72 hours of injury
3 physical symptoms of fat embolism?
confusion, petechiae, dyspnea
Diagnosis of fat embolism?
petechiae on chest, upper extremities, axilla, conjunctiva
Fat globules are in what 3 areas with fat embolism?
retina, sputum, urine
What happens to platelets in fat embolism?
thrombocytopenia
What happens to ETCO2, SaO2, and PAP in fat embolism?
increased PAP, decreased ETCO2, SaO2
What happens to ST segments in fat embolism?
suggestive of ischemia
Treatment of fat embolism?
stop surgery and mostly supportive care
Saphenous and superficial peroneal nerves are what kind of nerves?
small, unmyelinated c fibers (so don’t need a lot of LA)
When doing ankle block, don’t use what drug commonly added to LA if pt is diabetic?
epi
Needle size for ankle block?
22 g 1.5
