Mod10: Orthopedic Surgery - Regional Anesthesia Flashcards
Orthopedic Surgery
Advantages of Regional Anesthesia:
Enhanced rehabilitation
Earlier d/c home
(Decreased time to hospital discharge)
Improved postop analgesia
Decreased incidence N/V
(Less incidence of N/V – not necessarily with SAB)
Less respiratory & cardiac depression
Improved perfusion
(Improved perfusion and blood flow via sympathetic blockade)
Reduced blood loss
Decreased risk thromboembolism
Decreased postop cognitive dysfunction
(Potential for less postop delirium and cognitive dysfunction if sedation avoided altogether but usually provided in combination with at least a little sedation, sometimes in combo with GA)
Orthopedic Surgery
Neuraxial (spinal & epidural) techniques can possibly contribute to a reduced incidence of thromboembolic events (DVT & PE) by leading to…
Enhanced LE blood flow
(as the result of sympathectomy (vasodilation))
↓ PLT reactivity
Systemic anti-inflammatory effects of LA
Factor VIII and von Willebrand factor
(An attenuated postoperative increase in factor VIII (plays an important role in coagulation) and von Willebrand factor – (vWF plays important role in adhesion of PLTs – so this goes up after surgery - neuraxial techniques lessen the extent of this increase))
Antithrombin III
(An attenuated postoperative decrease in antithrombin III (antithrombin serves to inhibit coagulation by neutralizing thrombin – so a decrease in this will lead to enhanced coagulation – so neuraxial technique lead to less of a decrease in the activity of antithrombin III after surgery))
Stress hormone
(Changes in stress hormone release)
Orthopedic Surgery
Limitations of Regional anesthesia:
Motor block limits rehabilitation & early ambulation
Risk for falls and other injuries
Hypotension
Orthopedic Surgery - Regional anesthesia
Conversion to GA:
Always be prepared to convert to GA
Blocks can fail partially or completely, or duration of surgery can outlast block, or other complications can occur that require conversion to a GA
Always have airway equipment ready and machine checked and ready
Orthopedic Surgery - Regional anesthesia
Selecting a technique depends on:
Duration of surgery
Duration of postop analgesia needed
Degree of sensory/motor block necessary to allow for rehabilitation and ambulation
Orthopedic Surgery - Regional anesthesia
Contraindications:
Patient refusal
Infection at injection site
Systemic coagulopathy
-
Orthopedic Surgery - Regional anesthesia
Why are patients on antiplatelet agents, thrombolytics, fondaparinux, DTIs, therapeutic regimens of LMWH Not candidates for receiving (neuraxial blocks) spinal or epidural?
Risk for spinal or epidural hematoma
Orthopedic Surgery - Regional anesthesia
Neuraxial block placement or removal of neuraxial catheter are Not contraindicated with subQ heparin when dose is
< 10,000 units daily
Orthopedic Surgery - Regional anesthesia
With LMWH, guidelines on neuraxial administration is dependent on the regimen
Once-daily dosing =>
Neuraxial anesthesia can be administered, and
Neuraxial catheters can be removed 10-12 hours after previous dose, and then
There will have to be delay of four hours until next dose can be administered
Also suggested that these guidelines be utilized when considering placement of a deep Peripheral Nerve Block and plexus blocks and catheters
Orthopedic Surgery - Regional anesthesia
With LMWH, guidelines on neuraxial administration is dependent on the regimen
Twice-daily dosing =>
Neuraxial catheters cannot be left in and…
Need to be removed two hours before first dose of LMWH
Also suggested that these guidelines be utilized when considering placement of a deep Peripheral Nerve Block and plexus blocks and catheters
Orthopedic Surgery - Regional anesthesia
Patients on coumadin/warfarin are not candidates for neuraxial block unless INR is ….
Catheters shouldn’t be removed unless the INR is…
Normal
1.5 or less
Also suggested that these guidelines be utilized when considering placement of a deep Peripheral Nerve Block and plexus blocks and catheters
Orthopedic Surgery - Regional anesthesia
Brachial Plexus Blocks
list them:
Interscalene
Supraclavicular
Infraclavicular
Axillary
Orthopedic Surgery - Regional anesthesia - Brachial Plexus Blocks
Interscalene block
may be used for which procedure?
Surgery on shoulder, arm, elbow
Fibers that innervate the ulnar side of forearm and hand (C8-T1) may be spared
thus not recommended for surgery on the hand
Orthopedic Surgery - Regional anesthesia - Brachial Plexus Blocks
Supraclavicular block
Indications - Risk - Precaution:
Surgery on arm, hand, forearm, elbow
shoulder surgery also possible
Pneumothorax is most common serious complication of supraclavicular block (about 1% incidence)
Block of phrenic nerve occurs frequently (50% of procedures) but usually causes no clinically significant symptoms
=> BUT for this reason, bilateral supraclavicular blocks not recommended d/t fear of bilateral pneumo’s and bilateral phrenic nerve paralysis
Patients with COPD may not be ideal candidates for this block
Orthopedic Surgery - Regional anesthesia - Brachial Plexus Blocks
Infraclavicular block
Indication and disadvantages:
Surgery for arm - elbow - forearm - hand
Disadvantages:
Risk of vascular puncture and patient discomfort associated with traversing the pectoralis major and minor muscles
Orthopedic Surgery - Regional anesthesia - Brachial Plexus Blocks
Axillary block
Indication - Potential compliactions - Anesthesia considerations
<u>Surgery for:</u>
Hand - Forearm - elbow
<u>Potential complications: </u>
Intravascular injection - Nerve injury from needle trauma - Intraneural injection - Hematoma
<u>Anesthesia of hand can be achieved by:</u>
injecting LA solution at level of FA to block median, ulnar and radial nerves
useful for hand surgery when TQ NOT used
also to supplement brachial plexus block w/ incomplete sensory distribution
each of these blocks use 3-5 mL of LA
Orthopedic Surgery - Regional anesthesia
Forearm Blocks:
Median nerve block
provides most of the sensory innervation to palm of hand
Ulnar nerve block
provides sensory innervation to dorsal and palmar sides of ulnar aspect of hand
Radial nerve block
Superficial radial nerve is the distal sensory branch of radial nerve that follows radial artery along its course through the forearm
Most patients have radial dominance of sensation on the dorsal aspect of the hand; supplies innervation to dorsum of thumb and dorsum of hand
For many surgeries, an epidural or SAB is easier to perform than attempting to provide same extent of anesthesia with multiple PNBs…but certain co-morbidities (CAD, bacteremia, anticoagulation) may make a PNB the best choice for anesthetizing a lower extremity
Orthopedic Surgery - Regional anesthesia
Lower Extremity Blocks
Femoral nerve
Saphenous nerve
Sciatic nerve
Popliteal
Ankle
Orthopedic Surgery - Regional anesthesia - Lower Extremity Blocks
Femoral nerve block:
Anterior aspect of thigh and knee - Medial aspect of leg
Typically combined with other blocks (such as sciatic nerve block) to provide complete anesthesia below the knee
Can do continuous FNB
Alone or in combo with other PNBs – very useful for postoperative analgesia
Orthopedic Surgery - Regional anesthesia - Lower Extremity Blocks
Saphenous nerve block:
Saphenous vein stripping or harvesting
In combination with sciatic nerve block for medial foot/ankle surgery
Orthopedic Surgery - Regional anesthesia - Lower Extremity Blocks
Sciatic nerve block:
Provides nearly complete anesthesia of foot and lower part of leg
Often combined with FNB to provide more extensive anesthesia for LE
Foot and ankle surgery - BKA - Analgesia following knee surgery involving the posterior compartment
Orthopedic Surgery - Regional anesthesia - Lower Extremity Blocks
Popliteal nerve block:
Provides sciatic nerve anesthesia near the point where the sciatic nerve divides into the common peroneal and tibial nerve components
Most commonly used for foot and ankle surgery, usually in combination with femoral and saphenous nerve blocks
=> for surgery on medial aspect of leg or if TQ used
Orthopedic Surgery - Regional anesthesia - Lower Extremity Blocks
Ankle block:
For distal foot and toe surgery
Involves anesthetizing five** separate **nerves
Two deep nerves (tibial and deep peroneal), and
Three superficial nerves (superficial peroneal, sural, and saphenous nerves)
All nerses, except the saphenous, are terminal branches of the sciatic nerve
The saphenous nerve is a sensory branch of the femoral nerve
Knowledge of the anatomy of the ankle is essential
Orthopedic Surgery - Intravenous Regional anesthesia (IVRA)
Bier block:
Named after August Bier
Simple method of anesthetizing the arm or leg
Involves IV injection of large volumes of dilute LA solutions into an extremity after occlusion of the circulation by a tourniquet
For surgeries lasting two hours or less
Severe tourniquet pain and max allowable TQ time limit the duration of the block
Duration of postop analgesia also limited – not usually used when postoperative pain is expected to be significant
Orthopedic Surgery
General or Regional Anesthesia will depend on?
Proposed surgery - Anticipated length - Position required
Patient acceptance - Co-morbidities
Anticoagulation status
Orthopedic Surgery
Blood Loss significant in:
Spinal
(Scoliosis - Instrumentation)
Pelvic fracture repairs
Long bone fracture repairs
Total hip arthroplasty
Trauma