Anesthesia for orthopedics procedures Flashcards
During orthopedic procedures, the chance for surgical site infection (SSI) prevention is decreased by
administration of appropriate PREOPERATIVE ANTIBIOTICS in a timely fashion
Cefazolin pre-op time allotment for prevention of SSI
For cefazolin (a first-generation cephalosporin), the preoperative time allotment is within 1 hour of incision time;
Vancomycin pre-op time allotment for prevention of SSI
Within 2 hours of incision time
Organisms commonly associated with orthopedic procedures include
Staphylococcus aureus
gram-negative bacilli
coagulase-negative staphylococci (including S. epidermidis)
β-hemolytic streptococci
Prophylactic antibiotics are not indicated in _______ procedures such as ______________ procedures and procedures not involving implantations.
_________surgery with or without instrumentation should be covered by an antimicrobial agent
Prophylactic antibiotics are not indicated in clean procedures such as diagnostic arthroscopic procedures and procedures not involving implantations.
Spinal surgery with or without instrumentation should be covered by an antimicrobial agent
Recommended agent for antimicrobial prophylaxis for select orthopedic procedures
* None for orthopedic*
Cefazolin
What alternative agents are recommended when patients have a b lactam allergy for antimicrobial prophylaxis for select orthopedic procedures
Clindamycin or vancomycin
Why are tourniquets used during orthopedic surgery?
Tourniquets are often used in orthopedic surgery to minimize blood loss and provide a bloodless operating field.
What is important to consider when using a tourniquet during orthopedic surgery?
Appropriate cuff size and inflation pressure is paramount in reducing the risk of neuromuscular injury related to tourniquet ischemia.
Tourniquet inflation pressure for upper extremity surgery
70-90 mmHg above SBP
Tourniquet inflation pressure for lower extremity surgery
2 times over SPB
What is the duration of safe tourniquet inflation?
2 hours
During tourniquet use the pain usually begins ___________minutes after inflation and is transmitted by ________fibers (slow pain)
usually begins 45-60 minutes after inflation and is transmitted by C fibers (slow pain)
During tourniquet release for orthopedic procedures, the patient can manifest
Releasing the tourniquet produces transient changes including increased ETCO2,decreased body temperature, decreased blood pressure, decreased SVO2, and metabolic acidosis
Safety measures for preventing tourniquet complications include
Physiologic changes caused by tourniquets include
What is the first indication of BCIS under general anesthesia?
An abrupt decrease in end-tidal carbon dioxide concentration may be the first indication of clinically significant BCIS under general anesthesia.
What is Methyl methacrylate (MMA)?
A bone cement used during surgery
Bone Cement Implantation Syndrome (BCIS), is characterized by several clinical features, including:
Hypoxia*
Hypotension*
cardiac arrhythmias*
increased pulmonary vascular resistance*
unexpected loss of consciousness when regional anesthesia is administered*
cardiac arrest
Early signs of BCIS in the awake patient undergoing regional anesthesia:
dyspnea and altered sensorium
To ensure blood supply to the brain it is prudent to maintain the patient’s head in a
a neutral anatomic alignment while in the prone position
What is performed before cementing the patient with MMA ?
Blood pressure should be optimized.
The patient should be placed on a 100% fraction of inspired oxygen (FiO2),
pressure bags should be available for rapid intravenous (IV) fluid administration, and IV fluid bags should be full or nearly full.
It is also important to document the cement time on the anesthesia record.
Management of BCIS
inspired oxygen concentration should be increased to 100%, and supplementary oxygen should be continued into the postoperative period.
It has been suggested that cardiovascular collapse in the context of BCIS is treated as right-sided heart failure.
Aggressive fluid resuscitation is recommended, and hypotension should be treated with α-agonists.
Prone position complication
The increased intraabdominal or intrathoracic pressures resulting from being prone reduce venous return, and the cardiac output will be reduced.
In addition, placing a patient in the prone position increases systemic and pulmonary vascular resistance.
These increases lead to decreases in stroke volume and cardiac index.
The use of ____________controlled versus ____________controlled ventilation may allow for lower peak pressure in the ___________position
The use of pressure-controlled versus volume-controlled ventilation may allow for lower peak airway pressure in the prone position.
What support system allows a pressure-free abdomen and will minimize the effect on cardiac output?
the Jackson spine table or longitudinal bolsters for prone positioning,
Even if no arterial or venous compression occurs, if the patient’s head rests ________ the level of the heart, this creates an increased risk _________
Even if no arterial or venous compression occurs, if the patient’s head rests below the level of the heart,this creates an increased risk for postoperative visual loss
While turning the patient, special attention must be given to the __________ and __________.
Foam, gel pads, or head supports should be put in place ____________ turning.
Once the patient is turned, the first goal is to _____________and ________________
While turning the patient, special attention must be given to the head and the endotracheal tube.
Foam, gel pads, or head supports should be placed before turning.
Once the patient is turned,the first goal is to reconnect the breathing circuit and recheck the breath sounds to ascertain whether the tube is still in the correct place and has not migrated into the bronchus
The potential for eye or corneal injury is high in _____________ position.
Prone
Position related complications during shoulder arthroscopy- BEACH CHAIR position
Hypotensive bradycardic events
Cervical Plexus and hypoglossal nerve neurapraxias
Air embolism
Pneumothorax
DVT
Unilateral vision oss and ophthalmoplegia
Cerebral Hypoperfusion event
Position related complications during shoulder arthroscopy- LATERAL DECUBITUS position
Temporary paresthesia
Neurapraxias of the dorsal digital nerve of the thumb, musculocutaneous, ulnar, and axillary nerve
Permanent neurapraxias
Postoperative Stroke
DVT
Fluid-related obstructive airway compromise
Risk of musculotendinous nerve injury (5-oclock portal) (rare)
Tranexamic acid (TXA) MOA
TXA competitively blocks lysine receptors that activate plasminogen, preventing fibrin degradation.
In other words, it acts as an antifibrinolytic and maintains clot formation.
Administration of tranexamic acid (TXA) to patients undergoing total joint replacement because it has been shown to:
Decrease perioperative blood loss and transfusion requirements with minimal risk of complications
Administration dose and route for TXA
TXA (1–2 g) is administered perioperatively, either intravenously or topically at the surgical site.
