What the Anesthesiologist Should Know before the Operative Procedure
Hallux valgus correction is a procedure utilized to decrease pain and increase activity in patients with abduction and valgus rotation of the great toe with a prominent first metatarsal head.
Considerations with regard to the surgery include the type of surgery being performed including osteotomy, resectional arthroplasty, or a first meta-tarso phalangeal arthrodesis. The last two involve destruction of the joint and replacement or fusion, respectively.
Anesthetic considerations revolve around the etiology of deformity. Less concerning etiologies include biomechanical causes or trauma to the foot. While these are the most common etiologies, there are several systemic diseases that cause hallux valgus deformity that have significant anesthetic considerations, including connective tissue diseases such as gout, rheumatoid arthritis, psoriatic arthritis, Ehlers-Danlos syndrome, Marfan’s disease, and trisomy 21. Associated neurologic diseases include Charcot-Marie-Tooth disease, multiple sclerosis, and cerebral palsy.
Anesthetic techniques employed in these cases will depend on the degree of systemic involvement of the disease, as well as the pathophysiology. Considerations for each of the above mentioned systemic diseases are reviewed elsewhere in this work.
1. What is the urgency of the surgery?
What is the risk of delay in order to obtain additional preoperative information?
Hallux valgus correction surgery is an elective procedure and thus affords time to fully evaluate the patient’s medical status and optimize existing medical co-morbidities prior to proceeding with surgery.
2. Preoperative evaluation
In the majority of cases, a standard preoperative evaluation is sufficient. This would include a history to identify any problems with previous anesthetics, general, neuraxial, or regional. As well, a full medical history to determine cardiorespiratory reserve and any medical issues as well as current medications and allergies.
Physical exam includes standard vital signs, an airway assessment, cardiac and respiratory examination, and neurologic examination particularly if regional anesthesia is being considered as the primary anesthetic technique or for postoperative analgesia.
3. What are the implications of co-existing disease on perioperative care?
b. Cardiovascular system
The American College of Cardiology and American Heart Association (ACC/AHA) 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery proposed an algorithm for decisions regarding the need for further evaluation based on urgency of procedure, presence of active cardiac conditions (i.e., unstable coronary syndrome, decompensated heart failure, significant arrhythmias, or severe valvular disease), patient’s clinical risk factors and functional capacity, and the predicted cardiac risk of the planned procedure. Repair of hallux valgus is a nonemergent, intermediate-risk procedure that should proceed unless patient presents with an active cardiac condition or if further noninvasive testing would change perioperative management.
Many of these patients are elderly and may have preexisting pulmonary disease from a history of cigarette smoking and may have obstructive sleep apnea (OSA).
Chronic obstructive pulomary disease
Careful clinical history include pack years smoked, frequency of exacerbations, current symptomatic control, oxygen requirement, medication regimen, and available studies (spirometry). Unless suspecting acute exacerbation, pulmonary testing may be unnecessary and delay surgery.
Patients with sleep apnea should have the severity of the disease assessed, and appropriate strategies developed to reduce the potential for postoperative exacerbation of their disease by opioid-induced respiratory depression. They should continue the use of their continuous positive airway pressure (CPAP) therapy in the perioperative period.
Reactive airway disease (asthma)
Assess severity of disease including frequency of exacerbations, triggers, control and rescue medications, recent steroid therapy, emergency department (ED) visits, hospitalizations, intensive care unit (ICU) admissions, or prior intubations. Continue current mediations.
There are no specific concerns in these areas: presence of significant reflux disease (GERD) may impact airway management decisions.
Multiple sclerosis: Elective surgical procedures, whether under general or regional anesthesia, should be delayed during acute exacerbations. Spinal anesthesia is relatively contraindicated. Patients should be advised of the possibility of experiencing an acute exacerbation during the perioperative period. Peripheral nerve blockade should only be performed after a careful neurologic exam documenting any preexisting motor/sensory deficits.
Charcot-Marie-Tooth disease: Patients are extremely sensitive to nondepolarizing muscle relaxants and resistant to succinylcholine. Caution is required with neuraxial or peripheral nerve blockade techniques given possible exacerbation.
Cerebral palsy: Patients may be uncooperative due to cognitive disability or slow to emerge from general anesthesia. There are potential issues with positioning during surgery or for regional techniques owing to preexisting contractures. There is a high incidence of chronic aspiration with subsequent reactive airway disease and possibly pulmonary fibrosis. Up to 50% of patients with cerebral palsy have recurrent seizures.
g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
Rheumatoid arthritis (RA) is a autoimmune connective tissue disease with multisystem implications. Patients with RA can be on strong immunosuppressives up to and including corticosteroids that may require supplementation in the perioperative period. In evaluating patients with RA, there are several systems to consider. Airway control can be challenging if there is instability in the cervical spine, necessitating alternative methods of securing the airway. The cardiac system should be thoroughly evaluated as corticosteroids can accelerate atherosclerosis and rheumatoid nodules can result in dysrhythmias. The anesthesiologist should be aware of the possibility of pulmonary fibrosis and its implications. As well, patients with RA may have mononeuritis multiplex, possibly increasing the risk of neuropathy postoperatively after peripheral nerve blockade.
Marfan’s is a connective tissue disorder inherited in an autosomal dominant pattern with several concerns for the anesthesiologist. Among the cardiovascular concerns include weakened arterial walls leading to potential aortic dissection/rupture, conduction delays, and valvular prolapse/regurgitation. There are also concerns with emphysema and a restrictive ventilatory defect from kyphoscoliosis. The possibility of temporomandibular joint (TMJ) dislocation is also present.
Ehlers-Danlos syndrome, of which there are several variants, shares the same concerns as Marfan’s disease, but in addition has issues with venous fragility. It may prove difficult to secure/maintain intravenous access and be a contraindication to neuraxial anesthesia or peripheral nerve blockade.
Patients with trisomy 21 often have developmental delay, as well as issues with cooperation. Other major associated concerns are the potential for OSA, atlantoaxial instability, and congenital cardiac disease. These issues are more comprehensively covered elsewhere in this work
4. What are the patient's medications and how should they be managed in the perioperative period?
The majority of patients are rarely on medications specific to hallux valgus disease except for the possibility of analgesics. Medications are usually related to their premorbid condition if any are taken.
Herbal medications should be discontinued at least 7 days prior to surgery. Vitamins and over-the-counter medications can be continued in the majority of cases.
h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
If the etiology of the hallux valgus is secondary to rheumatoid arthritis or multiple sclerosis, patients may be on immunosuppressive agents that can potentially increase the risk of infection. As well, if patients are on steroids, supplementation may or may not be required.
i. What should be recommended with regard to continuation of medications taken chronically?
Renal: consider holding ACE inhibitors on the day of surgery
Antiplatelet: Clopidogrel should be stopped 7 days prior to surgery unless there has been recent percutaneous coronary intervention in which case it should be discussed with the cardiologist
Anticoagulants: indications for anticoagulant therapy should be evaluated and if warranted, briding therapy should be initiated
Analgesics: all long-acting opioids should be continued
j. How To modify care for patients with known allergies –
Known allergens should be avoided.
k. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
l. Does the patient have any antibiotic allergies-
Avoid antibiotics to which the patient is allergic.
m. Does the patient have a history of allergy to anesthesia?
Malignant hyperthermia (MH)
Documented: Avoid all trigger agents such as volatile agents and succinylcholine and ensure these are removed from the operating room prior to the patient’s arrival. It is preferable in this instance to avoid general anesthesia. Regardless of the anesthetic technique used, an MH cart should be immediately available.
Family history or risk factors for MH: A thorough history should elicit if the patient is at risk for the condition. If it is suspected then they should be ideally tested pre-operatively. If testing is not possible, it is safer to treat them as if they were MH positive, and a regional technique or local anesthetic technique may be the best anesthetic choice.
Local anesthetics/ muscle relaxants: If the patient has an allergy to local anesthetics it is important to determine in a history if this is to all local anesthetics and determine the names of the local anesthetics they are allergic to. If it is a true allergy then avoidance of these agents is preferred. If the patient has no allergy to an alternative local anesthetic this may be used if appropriate. If in doubt, and the previous reaction has been severe, then general anesthetic is advised. If the patient has an allergy to muscle relaxants these should be avoided. Ideally a regional technique should be used.
5. What laboratory tests should be obtained and has everything been reviewed?
Complete blood count (CBC) (platelet count), electrolytes, creatinine, international normalized ratio (INR).
Any further investigations are dependent on the patient’s preexisting comorbidities and issues identified during history and physical examination.
Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?
a. Regional anesthesia
Benefits:Avoids instrumentation of airway, prevents tourniquet-induced pain
Drawbacks: Standard risks of neuraxial anesthesia including hematoma, infection, nerve damage
Peripheral nerve block
Benefits: Avoids instrumentation of airway, prevents tourniquet-induced pain (depending on tourniquet location and block used), excellent postoperative analgesia
Drawbacks: Risk of nerve injury, local anesthetic toxicity, block failure
b. General anesthesia
Benefits: Definitive control of airway (if intubated), LMA (laryngeal mask airway) use also reasonable in the absence of contraindications such as severe reflux or requirement for prolonged positive pressure ventilation.
Drawbacks: Requires instrumentation of airway, increased risk of nausea/vomiting
c. Monitored anesthesia care
Hallux valgus repair 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 or ankle block.
6. What is the author's preferred method of anesthesia technique and why?
As long as there are no contraindications, the preferred method of anesthesia is spinal anesthesia along with single injection technique sciatic block at the popliteal level. Spinal anesthesia avoids instrumentation of the airway, as well as blocking the sympathetic response from tourniquet application on the operative limb. If a tourniquet is not used, ankle block is also a reasonable option for anesthetic management. Single injection sciatic nerve block at the level of the popliteal fossa provides long-duration analgesia in the postoperative period. Alternatives also include ankle block.
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; tourniquet discomfort is possible in prolonged procedures.
What can I do intraoperatively to assist the surgeon and optimize patient care?
Muscle relaxtion is rarely needed.
What are the most common intraoperative complications and how can they be avoided/treated?
Intraoperative complications are rare.
Cardiac: None anticipated.
Pulmonary: Standard postoperative pulmonary complications if general anesthesia is utilized.
Neurologic: Unique to procedure: There is a small risk of nerve injury from a nerve block.
b. If the patient is intubated, are there any special criteria for extubation?
There are no special criteria for extubation secondary to the procedure itself. Standard extubation criteria, if the case is performed under general anesthesia, include appropriate return of muscle strength, oxygenation/ventilation, airway reflexes, hemodynamic stability, and analgesia.
c. Postoperative management
What analgesic modalities can I implement?
multimodal analgesia – acetaminophen, nonsteroidal anti-inflammatory drugs, opioids
regional anesthesia – single injection popliteal or continuous catheter technique
What level bed acuity is appropriate?
Most cases are done on an outpatient basis. Unless indicated by the patient’s premorbid conditions, a standard postoperative ward is sufficient
What are common postoperative complications, and ways to prevent and treat them?
There are very few complications associated with anesthesia for this particular procedure. More commonly nausea and inadequate analgesia after general anesthesia can hinder discharge in what is often a ambulatory procedure. With respect to regional anesthesia, nerve injury, or complications from neuraxial anesthesia, though they exist, are exceedingly rare. Should a continuous catheter technique be used, appropriate arrangements to manage patient concerns/complications should be made prior to discharge. As well, prescriptions for analgesics should be provided to manage pain after removal of the continuous catheter.
Complications from the surgery itself are also rare, usually presenting long after the procedure as either nonunion, continued pain, or infection of the joint.
What's the Evidence?
Zaric, D. “Perisciatic infusion of ropivicaine and analgesia after hallux valgus repair”. Acta Anesth Scand. vol. 54. 2010. pp. 1270-5.
Casati, A. “Stimulating or conventional perineural catheters after hallux valgus repair: a double blind, pharmaco-economic evaluation”. Acta Anesth Scand. vol. 50. 2006. pp. 1284-9.
Capdevila, X. “Effect of patient controlled perineural analgesia on rehabilitation and pain after ambulatory orthopedic surgery: a multicenter randomized trial”. Anesthesiology. vol. 105. 2006. pp. 566-73.
Rodriguez, J. “Stimulating popliteal catheters for postoperative analgesia after hallux valgus repair”. Anesth Analg. vol. 102. 2006. pp. 258-62d.
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- What the Anesthesiologist Should Know before the Operative Procedure
- 1. What is the urgency of the surgery?
- What is the risk of delay in order to obtain additional preoperative information?
- 2. Preoperative evaluation
- 3. What are the implications of co-existing disease on perioperative care?
- b. Cardiovascular system
- c. Pulmonary
- d. Renal-GI:
- e. Neurologic:
- f. Endocrine:
- g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
- 4. What are the patient's medications and how should they be managed in the perioperative period?
- i. What should be recommended with regard to continuation of medications taken chronically?
- j. How To modify care for patients with known allergies -
- k. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
- l. Does the patient have any antibiotic allergies-
- m. Does the patient have a history of allergy to anesthesia?
- 5. What laboratory tests should be obtained and has everything been reviewed?
- 6. What is the author's preferred method of anesthesia technique and why?
- What prophylactic antibiotics should be administered?
- What do I need to know about the surgical technique to optimize my anesthetic care?
- What can I do intraoperatively to assist the surgeon and optimize patient care?
- What are the most common intraoperative complications and how can they be avoided/treated?
- b. If the patient is intubated, are there any special criteria for extubation?
- c. Postoperative management