What the Anesthesiologist Should Know before the Operative Procedure
Clubfoot (talipes equinovarus) is a common congenital defect that occurs in 1:1000 live births. The male-to-female ratio is about 2:1, with a bilateral occurrence of 50%. The majority of pediatric patients presenting with clubfoot will not be syndromic. Typically, clubfoot will occur as an isolated defect. However, it is important to note that clubfoot may coexist with a number of conditions, most common among these are myelomeningocele, arthrogryposis, and myopathies.
The etiology of clubfoot remains unclear. There is some evidence to suggest that the etiology of clubfoot is multifactorial. Most suspect a genetic involvement. The genetic basis is substantiated by the 33% concordance observed with identical twins. The mode of inheritance of clubfoot is not known. Environmental factors may also play a role.
Clubfoot is composed of four components. One can remember these components with the aid of the mnemonic CAVE: forefoot cavus and adduction, hindfoot varus, and ankle equinus. The first component, forefoot cavus is due to a contracture of the plantar fascia with plantar flexion of the forefoot on the hind foot, while, the second component forefoot adduction, is the result of medial deviation of the forefoot relative to the hind foot. Varus deformity comprises the third component and relates to the adduction and inversion of the calcaneus under the talus. Finally, the equinus deformity describes the increased degree of plantarflexion of the foot. Likewise, abnormalities of the muscles and ligaments of the affected limb may be present.
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1. What is the urgency of the surgery?
What is the risk of delay in order to obtain additional preoperative information?
There is no urgency with regards to the surgery for clubfoot repair.
Emergent: Surgery for clubfoot is never considered an emergency.
Urgent: Surgery for clubfoot is also not categorized as urgent.
Elective: Surgery for clubfoot repair is considered as elective. That being said,if left untreated clubfoot may lead to possible infection, difficultyand pain with ambulation, and ultimately disability. The surgery forclubfoot is usually performed during infancy.
2. Preoperative evaluation
Pediatric patients may present for clubfoot repair beginning at a few months of age to one year of age or slightly older. Routine pediatric clearance should be a requirement. The need for further evaluation willdepend on the presence of co-existing conditions. The abnormalities more commonly associated with clubfoot are arthrogryposis, myopathies, and myelomeningocele.
Medically unstable conditions warranting further evaluation include: unrepaired congenital heart lesions. These warrant assessment, consultation and stabilization prior to clubfoot surgery.
Delaying surgery may be indicated if a congenital cardiac lesion is present and has not been evaluated; other unstable medical conditions are present.
3. What are the implications of co-existing disease on perioperative care?
Clubfoot consists of several bone deformities described by the mnemonic CAVE. The most common coexisting diseases associated with club foot include arthrogryposis, myopathies, and myelomeningocele. Having some familiarity with their clinical features is imperative. More broadly, the impact of systemic disease is examined below.
Perioperative evaluation
It is important to determine the extent if at all there is evidence of co-existing disease in the patient presenting with clubfoot. The majority of information that will be incorporated into the perioperative care plan can be obtained by performing a complete history and physical examination.
Perioperative risk reduction strategies
Most patients presenting for clubfoot repair will more than likely not be taking medications on a chronic basis. In those situations where a patient is taking a chronic medication, it is probably best to continue it during the perioperative phase. However, it seems most prudent to have a discussion about the continued use of medication with the specialty physician and surgeon who are caring for the patient.
b. Cardiovascular system:
Perioperative evaluation
Congenital heart disease: There are several issues to consider before surgery can proceed. What is the nature of the lesion? Does this lesion require surgical repair? If yes, is cardiac surgery/procedure necessary before clubfoot surgery? The work-up will most definitely include pediatric cardiac consultation. Additional work-up may include any of the following: 12 lead electrocardiogram, echocardiogram, or cardiac catheterization prior to clubfoot surgery.
Perioperative risk reduction strategies
Monitoring: standard ASA monitors are appropriate.
Goals:
– Optimal myocardial perfusion and cardiac output.
– Myocardial function and cardiac output (avoid agents that cause excessive myocardial depression).
– Prevent deleterious changes in cardiac shunts.
c. Pulmonary:
There is no direct association between clubfoot and any specific pulmonary disorder. What may be encountered among pediatric patients presenting for clubfoot repair is a recent history of or currently with upper respiratory infection.
Upper respiratory tract infection (URI)
Perioperative evaluation: Thorough history and physical examination to establish the presence of URI signs or symptoms. The severity of URI symptoms will determine the need for cancellation of surgery.
Perioperative risk reduction strategies: Deep induction is used to obtund airway reflexes and prevent laryngospasm and desaturation. Laryngeal mask airway (LMA) may be considered as a safe alternative to endotracheal tube (ETT).
Asthma
Perioperative evaluation: Detailed assessment should include the frequency of wheezing, precipitating factor(s) (e.g., URI, exercise, environmental), steroid use, frequency of emergency room visits, hospitalizations, and the need for mechanical ventilation.
Perioperative risk reduction strategies: Maintenance therapy should be continued throughout the perioperative period. For the child receiving medical therapy only with exacerbation of asthma symptoms, consideration should be given to administering therapy on the morning of surgery. Prior to instrumentation of the airway, ensure that the patient is deep so that airway reflexes are obtunded to prevent laryngospasm, bronchospasm, and desaturation.
d. Renal-GI:
There is no direct association between clubfoot and renal disease.
e. Neurologic:
There is no direct association between clubfoot and neurologic disease.
f. Endocrine:
There is no direct association between clubfoot and endocrine disease.
g. 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)
Clubfoot is commonly diagnosed as a single defect. However, it is important to note the relatively high incidence of myopathies in children presenting with clubfoot. Clinical features to support the evidence of a myopathy may be lacking, but myopathic changes can be observed on muscle biopsies. In addition, clubfoot may be associated with arthrogryposis and myelomeningocele.
4. What are the patient's medications and how should they be managed in the perioperative period?
For the most part, the patient presenting for clubfoot repair will probably not be taking any medication.
h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
The majority of pediatric patients presenting for clubfoot repair will probably not have a history of medication use. However, those children with coexisting CHD may be taking cardiac medications on a daily basis. The decision as to whether or not these medications are continued during the perioperative period is best determined through a discussion with the pediatric cardiologist.
Cardiac medications: generalized suggestions for use during the perioperative period
Beta-blockers: continue perioperatively
Diuretics: consideration should be given to not administering on day of surgery
Digoxin: possibility to withhold on day of surgery
i. What should be recommended with regard to continuation of medications taken chronically?
Cardiac: See above for beta-blockers, diuretics, and digitalis.
Pulmonary: Continue daily regimen. If not on daily nebulizer/inhaled therapy, then use on day of surgery is recommended.
Renal, neurologic, antiplatelet, psychiatric: N/A
j. How to modify care for patients with known allergies
The preoperative assessment should include an inquiry of allergic reactions. Measures must be taken by the anesthesia provider to avoid the use of any such allergens. Depending on the allergen(s) identified, measures may even include some degree of preparation in the OR.
k. 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.
A vital part of the preoperative evaluation must include an inquiry of latex allergy. Latex allergy should be taken very seriously. Latex allergy can result in a severe, life-threatening anaphylactic reaction.
There are certain groups of children that are at a higher risk for developing latex allergy. For instance, children with recurring exposure to latex due to a history of myelomeningocele or urogenital anomalies. It is not unusual for these children to have undergone multiple surgical procedures before the age of one year. Children requiring multiple surgeries for other reasons or with a history of atopy may also be at risk. A query of adverse reaction on exposure to balloons, placement of a rubber dam in the mouth at a dental visit, and allergy to banana, kiwi, avocado and chestnuts should also be elicited. It is recommended that these high risk groups of patients be treated in a latex-free environment.
The majority of anesthesia equipment and products are latex-free. That being said, this can of course vary from one institution to another. Therefore, it is prudent that the anesthesia provider check the content of all anesthesia-related items.
l. Does the patient have any antibiotic allergies – Common antibiotic allergies and alternative antibiotics
The antibiotic group that is most allergenic are the penicillins. The typical adverse reaction is delayed and marked by a maculopapular rash and/or fever. Less common is immediate hypersensitivity that may be characterized by bronchospasm, laryngeal edema, and cardiovascular collapse. Structurally, cephalosporins share some similarities with penicillins. There is a rare instance of cross-reactivity between cephalosporins and penicillins. As a result, cephalosporins are often the antibiotic of choice in patients with a history of penicillin allergy. The most common antibiotic used in orthopedic procedures, such as for clubfoot repair is cefazolin, a first-generation cephalosporin.
m. Does the patient have a history of allergy to anesthesia?
Malignant hyperthermia
Documented: Avoid all drugs likely to trigger MH, such as inhalation anesthetics and succinylcholine.
Proposed general anesthetic plan: There are a number of nontriggering drug techniques that can be used to provide general anesthesia. Induction and/or maintenance drugs that do not trigger MH include propofol, ketamine, etomidate, barbiturates, narcotics, benzodiazepines, and nondepolarizing neuromuscular blockers.
Ensure MH care is available: Treatment for suspected MH should begin immediately with the following overview: I. Discontinue all triggering agents, and hyperventilate with 100% oxygen. II. Notify surgeon and get help. III. Administer intravenous (IV) dantrolene. IV. Administer bicarbonate for metabolic acidosis. V. Treat hyperkalemia, VI. Cool patient if core temperature >39ºC. VII. Follow labs and urine output.
Family history or risk factors for MH: The management should be the same as for a documented history of MH.
Local anesthetics/muscle relaxants
It is quite rare to observe an allergic reaction to local anesthetics. More likely to be the cause of an allergic reaction is para-aminobenzoic acid, a metabolite of ester local anesthetics. An additional cause for allergic reactions observed with the use of local anesthetics is due to the preservative methylparaben. Allergic reactions are known to occur occasionally following the administration of depolarizing or nondepolarizing neuromuscular blockers. The quaternary ammonium group in neuromuscular blocking agents appears to be responsible for the allergic reaction.
5. What laboratory tests should be obtained and has everything been reviewed?
From the perspective of the anesthesiologist, in an otherwise healthy child presenting for clubfoot repair, no laboratory tests may be required.
The expectation for blood loss associated with clubfoot repair isminimal. Generally, there is no need to obtain a preoperativehemoglobin. Review the laboratory requirements of your institution.
Hemoglobin levels, electrolytes, and coagulation panel: N/A
Imaging: lower extremity study (ordered by orthopedic surgeon)
Other tests: generally not indicated
Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?
The options for anesthesia during clubfoot repair include general, regional, and sedation techniques.
Regional anesthesia
This may be performed in the pediatric patient administered sedation or general anesthesia and includes neuraxial techniques and peripheral nerve blocks.
Neuraxial techniques are probably used more often in clubfoot surgery. However, peripheral nerve blocks should also be considered. In pediatric patients, peripheral nerve blocks may be performed as an adjunct to general anesthesia. Not only can a peripheral nerve block reduce general anesthesia requirements, but it also can provide postoperative analgesia. Pediatric patients can benefit from the combined techniques of sciatic and femoral nerve blocks or sciatic and saphenous nerve blocks when undergoing clubfoot surgery.
Peripheral nerve blocks
Sciatic nerve block: Several methods are described for sciatic nerve block. Most common among these are the anterior, lateral, and posterior approach. Any one of these three approaches may be used in children. The posterior approach will be reviewed here. The reader is advised to refer to a regional anesthesia textbook for more details.
Posterior Approach
The child should be placed with the side to be blocked in the nondependent position, with the leg flexed at the hip and knee. The needle should be inserted in a perpendicular plane at the midpoint between the coccyx and the greater trochanter of the femur. Correct needle placement can be confirmed with a peripheral nerve stimulator or use of ultrasonography. Pertaining to clubfoot surgery, the sciatic nerve block provides anesthesia to the anterolateral aspect of the leg, ankle, and foot.
Femoral nerve block: The femoral artery should be located slightly below the inguinal ligament. The needle should be inserted just lateral to the artery at approximately a 45-degree angle. Some “loss of resistance” should be noted as the needle is slowly advanced through the fascia lata and then the fascia iliaca. Ultimately, the needle should lie within the femoral canal where local anesthesia will be injected. A peripheral nerve stimulator or ultrasound guidance may be used. More specific to clubfoot surgery, the femoral nerve block will provide anesthesia to the medial lower leg and foot, where coverage tends to be lacking with the sciatic nerve block.
Saphenous nerve block: The saphenous nerve block may be combined with the sciatic nerve block instead of the femoral nerve block in the child undergoing clubfoot surgery. Keep in mind that the saphenous nerve is the terminal branch of the posterior division of the femoral nerve. Therefore, the saphenous nerve block is an acceptable substitution. The patient can be positioned supine with the leg laterally rotated. The needle is inserted at a 45-degree angle at a point that is in the distal and medial section of the thigh. The needle should be slowly advanced while observing a “loss of resistance” through the satorius muscle. The needle should rest in the plane below the satorius muscle where local anesthesia will be injected. A peripheral nerve stimulator or ultrasound guidance may be utilized. In clubfoot surgery, the saphenous nerve block will provide coverage to the medial aspect of the leg and foot.
Neuraxial
Benefits: It may be used to augment general anesthesia. Epidural (lumbar or caudal) anesthesia may be used for intraoperative anesthesia and postoperative analgesia. Less volume of local anesthesia is required with spinal anesthesia. Spinal anesthesia has a faster onset with more profound motor blockade.
Drawbacks: Positioning for placement of the block in an awake child may present challenges. Failure of the block may result in the use of general anesthesia. The surgical procedure may outlast the duration of anesthesia (possibility with single-shot technique). Contraindicated in the presence of major malformations of the lumbar and sacral regions. Family refusal will preclude placement.
Issues: Anticoagulation protocols are rarely a consideration in pediatric patients. Avoid in patients with clinically significant coagulopathy or thrombocytopenia.
Peripheral nerve block
Femoral nerve block, sciatic nerve block, and saphenous nerve block can be performed on children undergoing general anesthesia for unilateral clubfoot repair.
Benefits: When combined with general anesthesia, peripheral nerve blocks reduce the intraoperative anesthesia requirement. Local anesthesia can be limited to the area of involvement. Despite performance of the block under general anesthesia, the complication rate is low.
Drawbacks: The block may not provide adequate surgical anesthesia.
Issues: The use of peripheral nerve blocks may obviate the need for perioperative opioids and minimize the risk of respiratory depression.
General anesthesia
For most children, general anesthesia is the anesthesia technique of choice for clubfoot repair.
Benefits: It allows for a secure airway with endotracheal intubation; has rapid onset; provides greater ability to control duration of anesthesia; and is useful in noncooperative patients.
Drawbacks: Postoperative apnea (ex premie <60 weeks postconceptual age) and the possibility of postoperative vomiting (POV) or postoperative nausea and vomiting (PONV) are drawbacks.
Other issues: Issues include emergence delirium and subglottic stenosis.
Airway management: There can be difficult airway management in the presence of arthrogryposis.
Monitored anesthesia care
Monitored anesthesia care has limited use in clubfoot surgery; application in Ponseti (percutaneous tenotomy) clubfoot treatment.
Benefits: It is associated with less respiratory depression and provides rapid recovery.
Drawbacks:Patient movement is a possibility.
Other Issues:There is always the possibility of progression from a light level of sedation to deep sedation.
6. What is the author's preferred method of anesthesia technique and why?
The author’s choice of anesthesia technique is general anesthesia, combined with epidural placement for intraoperative and postoperative use. Perioperatively, pediatric patients do well with this combined technique. The emergence from anesthesia is marked by good pain control. During the postoperative period, a continuous infusion epidural is quite beneficial to the patient.
What prophylactic antibiotics should be administered?
For clubfoot surgery the recommended antibiotic is cefazolin. If the patient is allergic to β-lactam antibiotics, vancomycin or clindamycin are acceptable substitutes.
What do I need to know about the surgical technique to optimize my anesthetic care?
A number of modalities exist for the treatment of clubfoot. Much of the treatment of clubfoot has shifted from surgical release to a more conservative approach. Surgical treatment for clubfoot will be chosen when nonsurgical treatment has been unsuccessful. Surgical management may also be preferred with a recurring deformity that does not respond to nonsurgical management.
Nonsurgical treatment
The nonsurgical treatment options include serial manipulation and casting, taping, physical therapy, and splinting. The most commonly used modality for correction of clubfoot is the Ponseti technique. This technique involves sequential casting that may begin as a neonate. Following the completion of casting, an Achilles tenotomy may be required. Further correction can include manipulation and casting, which are followed by splinting and physical therapy. The French technique involves a program of daily manipulation and taping by a physical therapist over an extended period of time. The rate of success with this technique is less than with the Ponseti method.
Surgical treatment
Types of surgical procedures include (1) posteromedial release, (2) posterior release, and (3) subtalar release. The issue of whether or not muscle relaxation will be required during the surgery should be discussed with the surgeon.
What can I do intraoperatively to assist the surgeon and optimize patient care?
Lack of patient movement is a major concern during clubfoot surgery.
What are the most common intraoperative complications and how can they be avoided/treated?
Prioritize them by urgency. From the anesthesia perspective, intraoperative complications are not unique to this procedure.
Cardiac, pulmonary, and neurologic complications are not unique to this procedure.
a. Neurologic:
No neurologic adverse event is unique to this procedure.
b. If the patient is intubated, are there any special criteria for extubation?
The criteria for extubation should include an awake and spontaneously breathing patient with an appropriate tidal volume. Variation in responsiveness of the pediatric patient may be observed. The level of responsiveness may reflect the patient’s baseline behavior, age, or other factors.
c. Postoperative management
What analgesic modalities can I implement?
Analgesia can be provided via the intravenous route. If an epidural has been placed in the OR, then a continuous infusion in the postoperative period is recommended. Rectal acetaminophen can be considered as adjunct therapy.
What level bed acuity is appropriate?
The otherwise healthy pediatric patient may be transferred to the floor following a PACU stay. Admission to the pediatric intensive care unit will depend on the child’s comorbidities.
What are common postoperative complications, and ways to prevent and treat them?
Although emergence agitation/delirium may not be a common postoperative complication, it is deserves being mentioned. Emergence agitation/delirium is marked by inconsolability and nonpurposeful restlessness. It can be rather disconcerting to observe. It may be associated with disorientation, prolonged screaming and crying, as well as thrashing. There is no way to completely prevent the occurrence of emergence agitation/delirium. Pharmacologic and nonpharmacologic therapies are appropriate modalities.
What's the Evidence?
Colaço, H, Patel, S, Lee, M. “Congenital clubfoot: a review”. Br J Hosp Med. vol. 71. 2010. pp. 200-5.
Horn, BD, Davidson, RS. “Current treatment of clubfoot in infancy and childhood”. Foot Ankle Clin N Am. vol. 15. 2010. pp. 235-43.
Dobbs, M. “Clubfoot: Etiology and treatment [editorial]”. Clin Orthop Relat Res. vol. 467. 2009. pp. 1119-20.
Bor, N, Katz, Y, Vofsi, O. “Sedation protocols for Ponseti clubfoot Achilles tenotomy”. J Child Orthop. vol. 1. 2007. pp. 333-5.
Gastone, Z, Manani, G, Pittoni, G. “Prevalence of unsuspected myopathy in infants presenting for clubfoot surgery”. Pediatr Anesth. vol. 5. 1995. pp. 165-70.
Tobias, J, Menico, G. “Regional anesthesia for clubfoot surgery in children”. Am J Therap. vol. 5. 1998. pp. 273-7.
Foulk, D, Boakes, J, Rab, G. “The use of caudal epidural anesthesia in clubfoot surgery”. J Pediatr Orthop. vol. 15. 1995. pp. 604-7.
Black, M, Olney, B, Vitztum, C. “Administering caudal anesthesia at completion of clubfoot surgery does not affect postoperative use of narcotics”. Am J Orthop. vol. 32. 2003. pp. 130-2.
Rodrigues, M, Paes, F, Duarte, L. “Postoperative analgesia for the surgical correction of congenital clubfoot. Comparison between peripheral nerve block and caudal epidural block”. Rev Bras Anestesiol. vol. 59. 2009. pp. 688-93.
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