What the Anesthesiologist Should know before the operative procedure?
Patients undergoing ankle arthroplasty are generally elderly and have osteoarthritis or rheumatoid arthritis. Ankle arthroplasty is not a common surgical procedure, although interest has been renewed due to improvements in the prostheses. Ankle arthroplasty is generally considered a last resort for older, non-obese, sedentary patients.
1. What is the urgency of the surgery?
What is the risk of delay in order to obtain additional preoperative information?
Ankle arthroplasty is an elective procedure.
2. Preoperative evaluation
The procedure is elective; therefore, the patient’s medical status should be optimized prior to proceeding to surgery. Preoperative evaluation should include inquiry of potential comorbidities.
3. What are the implications of co-existing disease on perioperative care?
a. Cardiovascular system
Acute/unstable conditions: Acute or unstable conditions should be evaluated and managed according to the American College of Cardiology/American Hospital Association (ACC/AHA) guidelines for perioperative cardiovascular evaluation before proceeding with surgical repair.
Baseline coronary artery disease or cardiac dysfunction: Patients should be on optimal medical therapy to reduce risk of perioperative cardiac morbidity, such as aspirin, beta-blockers, and statins. Given that selected patients are often sedentary, it may be difficult to ensure that they do not have angina or dyspnea with exertion. In these patients a pharmacologic stress test (nuclear medicine or dobutamine echo) may be necessary. These patients often have arthritis in other joints, making an exercise stress test difficult.
b. Pulmonary
Reactive airway disease (asthma): Patients with reactive airway disease are at an increased risk of perioperative complications. Baseline reactive airway disease should be medically optimized according to National Heart, Lung, and Blood Institute (NHLBI) guidelines before proceeding with surgery. Baseline therapy should be continued throughout the perioperative period.
Chronic Obstructive Pulmonary Disease (COPD): Patients with COPD are at an increased risk of perioperative pulmonary complications. Baseline COPD should be medically optimized according to the American Thoracic Society (ATS) guidelines before proceeding with surgery. Baseline therapy should be continued throughout the period.
Obstructive Sleep Apnea (OSA): OSA is prevalent in the population although many patients go undiagnosed prior to surgery. Sleep apnea is associated with other pre-existing medical conditions such as obesity, hypertension, coronary artery disease, and diabetes that negatively impact perioperative outcomes. Appropriate screening should be utilized preoperatively to identify patients at high risk of OSA.
Reactive airway disease (asthma): Patients with reactive airway disease are at an increased risk of perioperative complications. Baseline reactive airway disease should be medically optimized according to the NHLBI guidelines before proceeding with surgery. Baseline therapy should be continued throughout the perioperative period.
c. Renal-Gastrointestinal (GI):
Renal system: The orthopedic surgeons may order a urinalysis to rule out a urinary tract infection prior to proceeding with an elective orthopedic surgery.
GI: Assess for symptoms of severe gastroesophageal reflux disease.
d. Neurologic:
Acute issues: Acute or unstable neurologic disorders (stroke, seizure) should be evaluated and managed before proceeding with surgery.
Chronic disease: Baseline treatment for chronic neurologic conditions should be continued throughout the perioperative period. Determine a baseline (neurologic exam) against which to assess new neurologic disorders in the postoperative period. Discuss signs or symptoms of peripheral neuropathy if placement of a peripheral nerve block or continuous peripheral nerve catheter will be utilized for postoperative pain control.
e. Endocrine:
Patients with diabetes mellitus should have their glucose control optimized to promote wound healing and reduce risk of infections.
f. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (e.g., musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
Patients may have rheumatoid arthritis. A thorough history is very important as further testing may be indicated. If the patient has neck involvement, flexion/extension radiographs may be necessary to rule out subluxation. Patients with rheumatoid arthritis may have a difficult airway.
4. What are the patient's medications and how should they be managed in the perioperative period?
Patients with rheumatoid arthritis may be on chronic steroids. A stress dose may be required in the operating room. Patients are encouraged to take their usual dose prior to surgery.
a. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
Patients undergoing ankle arthroplasty are likely to have osteoarthritis and may be taking aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs). The withdrawal or continuation of these medications is generally guided by the surgeon. Placement of peripheral nerve blocks or neuraxial anesthesia is not contraindicated in patients taking aspirin or other NSAIDs.
b. What should be recommended with regard to continuation of medications taken chronically?
Cardiac: Except for antiplatelet medications (see below) indicated for cardiovascular disorders, all other cardiac medications should be continued throughout the perioperative period.
Pulmonary: Pulmonary medications should be continued throughout the perioperative period.
Renal: Renal medications should be continued throughout the perioperative period.
Neurologic: Except for antiplatelet medications (see below) indicated for neurologic disorders, all other neurologic medications should be continued throughout the perioperative period.
Antiplatelet: Discontinuation of aspirin and GP2beta3alpha inhibitors should be balanced against the risk of perioperative thrombotic complications. Consultation with a cardiologist is indicated if these medications are taken because of an intracoronary stent
Psychiatric: Psychiatric medications should be continued throughout the perioperative period.
c. How to modify care for patients with known allergies?
Avoid medication and nonmedication allergens.
d. Latex allergy- If the patient has a sensitivity to latex (e.g., rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
All members of the operating room staff need to be aware of this condition.
e. Does the patient have any antibiotic allergies? (common antibiotic allergies and alternative antibiotics)
In cases of severe penicillin or cephalosporin allergies, pre-incisional vancomycin or clindamycin should be used for surgical prophylaxis.
f. Does the patient have a history of allergy to anesthesia?
Malignant hyperthermia (MH)
Documented: Avoid all trigger agents such as succinylcholine and inhalational agents. Follow a proposed general anesthetic plan: total intravenous anesthesia with propofol ± opioid infusion ± nitrous oxide. Ensure an MH cart is available [MH protocol].
Local anesthetics/muscle relaxants: Recall that local anesthetics belong to two chemical classes (amides and esters). If a true allergy is present, it is most likely due to an ester class local anesthetic. Indeed, even in this rare situation the allergy may be from a local anesthetic metabolite such as para-amino-benzoic acid (PABA) or a preservative. If a true allergy is suspected, either a local anesthetic from another chemical class should be used or local anesthetic use should be withheld.
5. What laboratory tests should be obtained and has everything been reviewed?
The patient’s age and comorbidities will direct the actual preoperative workup and testing required. The following are frequently ordered for patients undergoing ankle arthroplasty: hemoglobin, creatinine, blood type and screen, and ECG.
Intraoperative Management:
What are the options for anesthetic management and how to determine the best technique?
There is no consensus about the optimal anesthetic for patients undergoing ankle arthroplasty. General or neuraxial anesthesia are the most common options. Surgery can also be performed under epidural, combined spinal-epidural, or peripheral nerve block with or without the addition of sedation. There is currently no evidence that demonstrates superiority of one technique compared to the others. When making the anesthetic plan, it is important to consider the patient’s comorbidities and preferences as well as the surgical factors and postoperative disposition.
a. Regional anesthesia
Neuraxial
Benefits: Lower risk of postoperative nausea and vomiting (PONV), better short-term analgesia, avoidance of airway instrumentation.
Drawbacks: The usual risks of regional anesthesia, including nerve injury, bleeding, and infection. Postdural puncture headache is a potential drawback of neuraxial anesthesia, although the risk is extremely small in the elderly population.
Issues: The patient is generally positioned supine, so conversion to general anesthesia will be relatively straightforward. Caution must be used in patients who are anticoagulated. If epidural anesthesia is chosen, it is essential to discuss the choice of postoperative anticoagulation with the surgeon and remove the epidural at the appropriate time based on the ASRA Consensus Statement regarding anticoagulation.
Peripheral nerve block
The combination of a sciatic block and a lumbar plexus block would provide complete unilateral anesthesia and analgesia. If the sciatic or lumbar plexus (saphenous) block is performed at or below the level of the knee, a calf tourniquet must be used as patients would have pain with a thigh tourniquet.
Benefits: Unilateral lower extremity blockade, lower risk of PONV, better short-term analgesia (potentially longer analgesia if a continuous perineural catheter is used), shorter recovery, and avoidance of airway instrumentation.
Drawbacks: The usual risks of regional anesthesia, including nerve injury, bleeding, and infection.
Issues: Similar to those for neuraxial anesthesia.
Local anesthetic infiltration
Local anesthetic can be infiltrated directly into the surgical site by the orthopedic surgeon to provide postoperative pain control in patients who do not receive a peripheral nerve block. Liposomal formulations have the potential to provide long-lasting analgesia.
Benefits: Relatively simple technique.
Drawbacks: The usual risks of local anesthetics remain, including local anesthetic systemic toxicity.
Issues: Relatively new technique for ankle arthroplasty.
b. General anesthesia
Benefits: The patient’s airway is secured with an endotracheal tube or laryngeal mask airway.
Drawbacks: Usual side effects and risks of general anesthesia, including PONV, postoperative cognitive dysfunction, allergic reactions, MH, airway trauma or lost airway.
Other issues: Appropriate patient positioning and padding.
Airway concerns: Patients with osteoarthritis or rheumatoid arthritis may have a difficult airway. Preoperative assessment is essential.
c. Monitored anesthesia care
Ankle arthroplasty is an invasive procedure involving significant work on the bone, therefore it should not be performed under sedation alone. Sedation may often be combined with neuraxial or peripheral nerve blockade.
6. What is the author's preferred method of anesthesia technique and why?
The foot/ankle surgeons at our institution commonly perform ankle arthrodesis, although the anesthetic management would be similar for an ankle arthroplasty. We typically place a single injection or continuous popliteal sciatic nerve block (the choice of single injection versus continuous catheter is based on surgeon preference) and a single injection saphenous or femoral nerve block. We then combine this with a general anesthetic or a spinal anesthetic because the blocks are placed immediately preoperatively and there is insufficient time for block set-up prior to the incision.
What prophylactic antibiotics should be administered?
Preincisional cefazolin or cefuroxime is recommended. Vancomycin or clindamycin may be used for patients with severe allergies to penicillin or cephalosporin.
What do I need to know about the surgical technique to optimize my anesthetic care?
The patient is placed supine and a tourniquet is often used to minimize intraoperative blood loss.
What can I do intraoperatively to assist the surgeon and optimize patient care?
Muscle relaxation is rarely needed.
What are the most common intraoperative complications and how can they be avoided/treated?
Intraoperative complications are rare.
Cardiac complications are anticipated. Standard postoperative pulmonary complications can occur if general anesthesia is used. Neurologic complications are unique to procedure (see below).
a. Neurologic:
There is a small risk of postoperative foot numbness resulting from procedure-related nerve injury.
b. If the patient is intubated, are there any special criteria for extubation?
Ensure that the patient is awake and alert and responds appropriately to commands.
c. Postoperative management
What analgesic modalities can I implement?
A sciatic block (continuous infusion or single injection) may be placed for postoperative pain control. A femoral or saphenous block must be added for complete analgesia of the distal lower extremity. Multimodal analgesia is useful to limit the side effects and maximize the benefits. Non-steroidal anti-inflammatory agents, acetaminophen, and small doses of opioids can be used to provide pain relief in the postoperative period.
What level bed acuity is appropriate?
Standard floor care is expected, although intensive care unit (ICU) may be considered based on specific patient comorbidities.
What are common postoperative complications, and what are the ways to prevent and treat them?
The most severe complications are pulmonary embolism (PE), deep venous thrombosis (DVT), and surgical site infection. DVT prophylaxis with mechanical compression devices and anticoagulants may be indicated.
What's the Evidence?
TOTAL ANKLE ARTHROPLASTY
Raikin, SM, Kane, J, Ciminiello, ME. “Risk factors for incision-healing complications following total ankle arthroplasty”. J Bone Joint Surg Am. vol. 92. 2010. pp. 2150-5.
Kitaoka, HB, Patzer, GL. “Clinical results of the Mayo total ankle arthroplasty”. J Bone Joint Surg Am. vol. 78A. 1996. pp. 1658-64.
Bai, LB, Lee, KB, Song, EK, Yoon, TR, Seon, JK. “Total ankle arthroplasty outcome comparison for post-traumatic and primary osteoarthritis”. Foot Ankle Int. vol. 31. 2010. pp. 1048-56.
Gougoulias, N, Khanna, A, Maffulli, N. “How successful are current ankle replacements?: A systematic review of the literature”. Clin Orthop Relat Res. vol. 468. 2010. pp. 199-208.
Steck, JK, Anderson, JB. “Total ankle arthroplasty: indications and avoiding complications”. Clin Podiatr Med Surg. vol. 26. 2009. pp. 303-24.
Gallardo, J, Lagos, L, Bastias, C, Henríquez, H, Carcuro, G, Paleo, M. “Continuous popliteal block for postoperative analgesia in total ankle arthroplasty”. Foot Ankle Int. vol. 33. 2012. pp. 208-12.
DeOrio, JK, Gadsden, J. “Total ankle arthroplasty and perioperative pain”. J Surg Orthop Adv. vol. 23. 2014. pp. 193-7.
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