Ortho Flashcards
Polymethylmethacrylate
- Bone cement
- Frequently required for joint arthroplasties
- Binds prosthetic device to the patients bone - causing an increase the intramedullary pressure
Complications when intramedullary pressure increases
o Fat, bone marrow, cement, or air emboli
o Vasodilation and ↓ in SVR
o Platelet aggregation and microthrombus formation
o Hypoxia
o Hypotension
o Dysrhythmias
o Pulmonary hypertension an increase in PVR
o ↓ CO
Interventions for increased intramedullary pressure (w/ bone cement)
o Increase FiO2
o Maintain euvolemia
o Treat arrhythmias
o Surgeon can create a vent hole in the distal femur to relieve intramedullary pressure
Pneumatic Tourniquets:
• Creates a bloodless field that facilitates surgery
Pneumatic Tourniquets: inflation pressure
100 mmHg over systolic blood pressure
Pneumatic Tourniquets:
Prolonged inflation of >2 hours can lead to
transient muscle dysfunction / myopathies / pain
o peripheral nerve injuries
o rhabdomylsis
Pneumatic Tourniquets:
Other potential problems
o Hemodynamic changes o Pain o Metabolic alterations o Arterial thromboembolism o Pulmonary embolism • Tourniquet pain
Tourniquet pain
un-myelinated slow conducting C-fibers
o Pain usually begins 45-60 min into procedure
o Pain may become so severe that patients may require GA despite the regional block – Spinal Anesthetic
o Progressive sympathetic activation
o Cuff deflation immediately relieves tourniquet pain and associated hypertension
o When the tourniquet is released you will see….
cause ↑’s in PaCO2, ETCO2, serum lactate and potassium levels
When applying the tourniquet
Limb must be padded and the cuff must fit and be properly applied to the correct extremity
Fat Embolism Syndrome: presents in -
72 hours of long bone or pelvic fractures
o long bones = femur / humerus / pelvis
Fat Embolism Syndrome: Signs and symptoms:
o Dyspnea, hypoxia
o Confusion or agitation
o Petchiae on the chest, upper extremities, axillae and conjunctiva
o Fat globules may be found in the retina, urine or sputum
o During GA: ↓ ETCO2 and arterial O2 saturation, ↑ pulm artery pressure
Fat Embolism Syndrome: mechanism
not known but is thought to occur due to the release of fat globules from fractured bone which enter torn medullary vessels
Fat Embolism Syndrome: Treatment
o Early fracture stabilization
o Oxygen and intubation with continuous positive airway pressure ventilation
o If the patient is coding - Start ACLS protocol
o High dose corticosteroids may be of beneficial use
Deep Vein Thrombosis & Pulmonary Embolism
- Most common after orthopedic surgery on the pelvis and lower extremities
- Occurs due to venous stasis and a hypercoagulable state due to localized and systemic responses to surgery
Deep Vein Thrombosis & Pulmonary Embolism
- pts at risk
Hip surgery or knee reconstruction patients o Obese patients o Over the age of 60 o The use of a tourniquet o Greater than 4 days immobilization
how to decrease risk of DVT and PE -
• Prophylactic anticoagulation and use of pneumatic leg compression devices decreases incidence of DVT
• If patients are on anticoagulation prophylaxis, spinal or epidural needle placement or catheter removal should
not take place until 6-8 hours after heparin dose or 12-24 hours after LMWH
• Anticoagulants may be started after surgery -
o Heparin 5,000 units q8˚ or LMWH
Compartment Syndrome:
there is an increased pressure – typically caused by inflammation – within the facial compartment – which first impairs venous and lymphatic drainage and eventually arterial blood flow to the tissues – this decreased blood flow to the tissues can lead to nerve damage and muscle death
Compartment Syndrome:
Most commonly seen in
anterior and posterior compartment of the leg
Compartment Syndrome:
increased pressure impedes
venous, lymphatic and eventually arterial flow
Compartment Syndrome: reduction of blood flow causes
ischemia, pain, and may cause paresthesias
• Can lead to nerve damage and muscle death if severe and untreated
Compartment Syndrome: treatment
medical emergency and requires a fasciotomy
UTIMATELY the ____________ is responsible for the proper positioning of the patient on the OR table
CRNA
Surgical pause:
• Initiated by surgeon to identify correct limb or area of surgery before operation begins
o Correct patient / Correct procedure / Correct limb
o Initials marked on the site prior to surgery
• Used to prevent wrong site surgery
the most frequently used anesthetics for ortho
• Regional, General Anesthesia, and MAC with sedation and a local anesthesia (LA) field block
Factors that influence the type of anesthetic used:
Patient preference o Patient state of health o Expertise of anesthetist o Duration of Procedure o Surgeon Preference o Practice patterns of hospital - some hospitals may have more resources than other
Arthroscopy
• Examination of the interior of a joint with an endoscope
Arthroscopy: • Benefits
o ↓ blood loss o ↓ postoperative pain o ↓ hospital time o ↓ length of rehabilitation o Equals decreased healthcare cost and improved patient satisfaction
Arthroscopy: Complications
o Inadvertent extubation o Eye/corneal injury o Nerve injury o Tourniquet complications o Vascular injury o Volume overload from fluid absorption
Arthroscopy: If a patient does become volume overloaded
treat them with fluid restriction / oxygen / diuretics / monitor hemodynamics
Knee arthroscopy:
Used for diagnosis and/or repair of the meniscus, loose body removal this could be from cartilage micro-fracture, or cruciate ligament repair mainly the anterior ligament repair
Knee arthroscopy: position
Supine position with the foot of the bed lowered
Knee arthroscopy: Anesthetic considerations
o Spinal anesthesia w/ MAC
o General anesthesia with a LMA and surgeon injects LA
Shoulder Arthroscopy:
Used for repairs of the rotator cuff, labral tears, frozen shoulder and other shoulder complications
Shoulder Arthroscopy: most commonly done for-
ROTATOR CUFF REPAIR (RCR)
Shoulder Arthroscopy: position
lateral decubitus or beach chair
Shoulder Arthroscopy: Complications
o Subcutaneous emphysema
o Pneumothorax
o Pneumomediastinum
o Hypoxic brain injury
Hypoxic brain injury
- Usually related to beach chair position & hypotension
- Anesthetist will give a Propofol drip or beta-blocker to get systolic less than 100 mmHg, usually around 90 mmHg. Research shows controlled hypotension can contribute to hypoxic brain injury. Try to avoid this -
- keep systolic > 100mmHg / don’t let it fall below 20% of baseline
Shoulder Arthroscopy: Anesthetic considerations
o Positioning and airway access can be limited
o Maintain normothermia
o Put monitors in non-operative arm
Shoulder Arthroscopy:
Combination interscaline block or HIGH brachial plexus block: Complications:
interscaline block - can lead to phrenic nerve paralysis -which would paralyze half the diaphragm or Horner’s Syndrome
Horner’s Syndrome
pitosis
miosis
endopthalmus
anhydrosis
Arthroplasty:
Surgical replacement of a joint to gain the return of natural range of motion and function of the joint
-Arthroplasty is used for restoration of the controlling function of the surrounding soft tissues - such as the muscles, ligaments and tendons
Arthroplasty:
• Total arthroplasty
• Hemiarthroplasy
- Total arthroplasty = total joint replacement
* Hemiarthroplasy = partial joint replacement
Arthroplasty: Goals include:
o Pain relief
o Stability of joint motion
o Deformity correction
Arthroplasty: Joints are replaced with
Prostheses made from strong metal alloys such as cobalt or titanium
Complications of arthroplasty:
o Blood loss
o Infection
o Thromboembolism
o Nerve injury
Most commonly replaced joints:
o Hip
o Knee
Arthroplasty:
Anesthetic considerations:
o Spinals are used for sick patients - a lot of elderly patients who fall and fracture their hips
o General Anesthesia is reserved for those who do not consent to Regional
• Again, anesthesia is responsible for patient positioning and maintaining normothermia,
• Procedures can last from 1-4 hours
Hip arthroplasty:
Also known as total hip replacement
Hip arthroplasty: position
Supine can be used – on a FRACTURE TABLE
Lateral decubitus position
Hip arthroplasty: general info
- Large incision from iliac crest to mid thigh
- Several large muscle groups are incised and dissected
- Joint is disarticulated and femoral head and neck are excised leaving the femoral canal open
- During reaming process venous sinuses can be opened and destroyed leading to significant blood loss
Hip arthroplasty: Anesthetic considerations specific to hip arthroplasty:
- Frequently are elderly patients with co-existing diseases
- VOLUME DEPLETED
- blood loss can be up to 6 units or 2-3 L
- LATERAL DECUBITUS POSITION using a HYPERBARIC spinal
pt on plavix
stop 7 days prior- put on aspirin
Knee arthroplasty:
- Also know and total knee replacement
- Supine position w/ tourniquet
- done for degenerative joint disease
Knee arthroplasty: Anesthetic considerations
o Similar to THA
o Supine
o Spinal w/ MAC
Open Reduction Internal Fixation:
• Known as ORIF
ORIF: OPEN REDUCTION
open surgery to set bones - necessary for some fractures
ORIF: INTERNAL fixation
refers to fixation of screws or plates to enable and facilitate healing. Keeping the bone in its normal position
ORIF: RIGID fixation
prevents micro motion across lines of the fracture and helps to enable healing and prevent infection.
ORIF: EXTERNAL fixation
is a surgical treatment used to set bone fractures in which a cast would not allow proper alignment of the fracture
ORIF: Anesthetic considerations
- Emergency cases are considered full stomachs and aspiration prophylaxis should be implemented
- Consider that the patient may be acutely intoxicated with alcohol and/or drugs
Depressants effect on MAC: alcohol and narcotics
- acute
- chronic
o Acute usage (acutely intoxicated) – DECREASED MAC
o Chronic usage - INCEASED MAC
Stimulants effect on MAC: amphetamines / cocaine
o Acute usage- INCREASED MAC
o Chronic usage- DECREASED MAC
patients who are chronic uses of stimulants usually have decreased catecholamine stores - **some may need an increased MAC – due to enzyme induction, but essentially your going to treat the patient accordingly to what’s going on at the time
Marijuana/Cannabis effect on MAC:
o Acute usage- DECREASED MAC
o Chronic usage- INCREASED MAC
Anesthetic Management for Hand and Foot Surgery
• Foot surgery is usually done by podiatrists
• Tourniquets are frequently used
• Most hand procedures can be done under general anesthesia using short acting anesthetics (S.A.F.E.) with LMA
o S.A.F.E. – short-acting, fast emergence
carpal tunnel release
usually done using a Bier Block or general anesthesia with an LMA
Bier Block:
o IV REGIONAL anesthesia
o Start IV in hand, exsangunate the arm, inflate tourniquet, and inject 50 ml of 0.5% Lidocaine
- TQ up for at least 20-25 minutes
ANKLE BLOCK
23-25 gauge needle and 5-8 ml of LA – Lidocaine or Marcaine is injected at the site after aspiration – your doing a type of a field block around where these nerves are
ANKLE BLOCK: nerves
- Femoral nerve terminal branch is the
1- SAPHENOUS nerve – is at distal end of tibia - also known as the lateral malleolus
- Sciatic nerve terminal branches: 2- Posterior tibial nerve – back medial aspect. 3- Deep peroneal nerve 4- Superficial peroneal nerve 5- Sural nerve
Series of 5 different injections - essentially doing a circumferential block – AVOID…..
EPINEPHRINE in your local anesthetic.
Brachial plexus nerves and where they originate
- roots (C5-T1)
- trunks: superior (C4-C6), middle (C7), inferior (C8 & T1)
- Divisions: 3 ventral and 3 dorsal
- cords: lateral, medial, and posterior
- branches: axillary, musculocutaneous, radial, median, ulnar
