Abstract

INTRODUCTION

Cerebral palsy (CP) is a common cause of morbidity and disability in childhood. CP is a heterogeneous group of chronic nonprogressive disorders of motor development and posture in children that are associated with cognitive and neurosensory disturbances.[1,2]

The prevalence in the general population in developed world is about 1:500 live births.[2,3]

Most cases of CP arise from intrauterine – antepartum causes. Birth asphyxia, perinatal ischemia and hypoxia, congenital malformations, intraventricular hemorrhages, intrauterine infections – all contribute to the development of CP.[4,5,6,7,8,9,10,11,12]

A child with CP can present for surgery, and anesthetic management is challenging because of the involvement of various organ systems and associated complications. Central nervous system is often involved, and they can present with varying degrees of movement disorders as described below.

CLASSIFICATION

Swedish classification shown below is the most widely used as it addresses both movement disorder as well as its distribution.[4,8,9,10,13]

Spastic CP (70%):

• Quadriplegia

• Diplegia

• Hemiplegia.

Dyskinetic CP (10%):

• Dystonia

• Athetosis

• Chorea.

Ataxic CP (10%):

• Intention tremor and head tremor (titubation).

Mixed (10%):

• For example, spastic athetosis.

PATHOPHYSIOLOGY AND CLINICAL MANIFESTATIONS[9,13,14]

MEDICAL MANAGEMENT OF CEREBRAL PALSY[4,8]

• Children with CP are often on treatment with multiple medications for associated conditions. In the preoperative history, all current medications should be recorded, including anticonvulsants, antispasticity, and antireflux medications[13]

• Medical therapy for controlling seizures, spasticity, reflux, constipation, and depression should be well understood, in particular with respect to side effects and potential interactions

• Carbamazepine and sodium valproate are prescribed for seizure management. While carbamazepine can cause induction of hepatic enzymes, leading to reduced duration of action of vecuronium, sodium valproate is known to cause impaired platelet function, increased risk of bleeding, hepatotoxicity, and bone marrow suppression

• Medications commonly used for spasticity include - diazepam, baclofen, tizanidine, dantrolene sodium, and botulinum toxin

  • Benzodiazepines cause sedation, respiratory depression, and dependence. Common problems reported with baclofen are muscle weakness, malaise, nausea, diarrhea, skin rash, and abnormal liver function tests (LFTs). Both baclofen and dantrolene are known to complicate the resumption of adequate respiratory effort during emergence from anesthesia. Tizanidine can cause dry mouth, muscle weakness, reversible abnormalities in LFTs, and hypotension. Drug-induced hepatitis and hallucinations are rare, serious side-effects[18]

  • Botulinum toxin causes dose-dependent, reversible muscle denervation, muscle atrophy if given long-term. It also leads to fatigue, transient weakness of the injected muscle. Generalized weakness or systemic toxicity is rare. May potentiate the action of muscle relaxants (not proven clinically).

COMMON SURGERIES IN CEREBRAL PALSY[4,8,9]

Children with CP can present for many interventional diagnostic and surgical procedures. A detailed knowledge of these procedures is essential for the treating anesthesiologist. Commonly performed surgical interventions in these children include:

• Tracheostomy

• Dental surgeries

• Orthopedic surgeries – rhizotomy-contracture release, tendon lengthening, and scoliosis correction

• Diagnostic endoscopy

• Nissen fundoplication

• Feeding gastrostomy.

ANESTHETIC IMPLICATIONS AND SURGICAL MANAGEMENT

• Perioperative anesthetic implications in child with CP vary with the severity of the disease as well as associated medical conditions

• Spasticity is a crippling feature of CP. Children are often on antispastic mediations preoperatively. Baclofen should not be withheld abruptly. Seizures are common. It is important to keep a detailed account of ongoing anticonvulsant medications during preanesthetic work-up and to continue these anticonvulsants perioperatively

• Antireflux medications for GOR must be continued perioperatively. Increased oropharyngeal secretions can contribute to increased the risk of aspiration, recurrent pneumonia, and reactive airway disease in these children. To minimize this problem, anticholinergics must be given intravenously once this access is secured. It is necessary to suction the oropharynx immediately following anesthesia. Some patients may have already been started on anti-sialogogue such as glycopyrrolate preoperatively itself

• Airway assessment must focus on possible difficult laryngoscopy due to abnormal dentition, temperomandibular joint dysfunction, and positioning difficulties. The previous anesthetic records can be of help in airway management

• Care must be taken while positioning to prevent pressure sores, especially during prolonged orthopedic surgeries

• Preoperative anxiety needs to be well managed as many of these children may not communicate effectively or may have undergone multiple surgeries. Premedication with oral or intravenous midazolam is appropriate in such cases

• Minimum alveolar concentration (MAC) is reduced for inhalational agents. MAC of halothane has been shown to be 20% lower in children with CP and a further 10% lower in those currently taking anticonvulsants. There is resistance to nondepolarizing muscle relaxants, attributable due to drug interaction with anticonvulsants, and chronic immobilization[19,20,21,22,23]

• Children with CP are more prone to develop hypothermia perioperatively. Hypothermia can be precipitated by decreased circulatory volume, increased blood loss during surgery

• Perioperative chest physiotherapy will help those with poor cough, poor secretion clearance, and recurrent chest infections

• Judicious postoperative suctioning helps in clearing the pooled secretions

• Patients with poor respiratory function might require postoperative ventilation and even tracheostomy during weaning

• Meticulous care must be taken in positioning the patient during regional anesthesia, to overcome difficulties caused by contractures, and spine deformities such as scoliosis

• Important anesthetic implications and management strategies are summarized in Table 1.

  Table 1

  Important anesthetic considerations and management strategies in a pediatric patient with cerebral palsy for surgery

  

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ANESTHESIA FOR ORTHOPEDIC PROCEDURES INCLUDING SCOLIOSIS

• Most of the orthopedic surgeries performed in children with CP are to treat the chronic effects of increased tone on muscles and bones of extremities and spine. Commonly performed surgeries include soft-tissue release surgeries, tendon transfers, osteotomies, tenotomies, and scoliosis correction

• Usually, the major surgical procedures are done under combined general anesthesia (GA) and regional analgesia[24]

• In pediatric patients, it is common practice to administer caudal epidural analgesia along with GA to decrease intraoperative inhalational anesthetic requirements and postoperative pain[4,13,25]

• Epidural analgesia, in particular, continued into the postoperative period will diminish both postoperative pain and muscle spasm

• GA

  • Standard monitoring along with temperature monitoring and neuromuscular monitoring are important. Monitoring the depth of anesthesia is helpful as the MAC value is varied

  • Induction of anesthesia may be challenging. This is mainly attributable to intellectual disability causing lack of cooperation, communication difficulties, and difficult intravenous access. This is particularly so in those children who have previously been in special care baby units or neonatal intensive care; who may have previously used and scarred veins. The presence of an assistant and topical application of EMLA cream is often helpful to establish vascular access. If intravenous induction of anesthesia is planned, all commonly used agents are suitable, although propofol appears to be more painful in these patients

  • Airway management in the presence of increased incidence of GOR in this group of patients varies

  • Many anesthesiologists choose a laryngeal mask airway when clinically appropriate in conjunction with a nasal or oral gastric tube aspirated and left on free drainage; others chose a tracheal tube routinely

  • GA is indicated for scoliosis correction. Surgery for scoliosis is associated with deterioration in the respiratory function. Preoperative respiratory function tests are unreliable and not predictive of outcome. Postoperative nasal continuous positive airway pressure may help to prevent respiratory complications. Occasionally, the patient may require long-term ventilation; tracheostomy can be considered during weaning[4]

  • Reduced MAC and hypothermia contribute to emergence-related problems.

• Regional anesthesia

  • Regional techniques are preferred for intra- and post-operative analgesia in most major procedures

  • Epidural analgesia is preferred neuraxial technique for lower limb surgery

  • Epidural catheter insertion requires an experienced anesthesiologist as associated scoliosis and prior back surgery may make insertion challenging

  • Any regional infusion must be carefully monitored by an experienced pain management team and well-trained nursing staff

• Postoperative pain management[14]

  • Postoperative pain following lower limb orthopedic surgery is managed in these children with continuous epidural infusions (caudal or lumbar):

  • Lidocaine (1.5–2 mg/kg/h) plus fentanyl (0.5 mcg/kg/h)

  • Bupivacaine (0.625–1 mg/ml/h) with or without fentanyl (0.5 mcg/kg/h)

  • Hydromorphone (2–4 mcg/kg/h).

• Muscle spasms are virtually universal and are treated prophylactically with intravenous diazepam 0.1–0.2 mg/kg or addition of clonidine to the postoperative epidural infusion at a dose of 0.08–0.12 mcg/kg/h.

ANESTHESIA FOR ANTIREFLUX SURGERY

• Children with CP often present for antireflux surgeries, mainly Nissen fundoplication

• Compared to laparoscopic technique, the open technique is associated with significant morbidity; hence, laparoscopic methods are preferred over open techniques in CP

• GA is the choice of anesthesia for these surgeries. Anesthetic management here is same as described earlier

• The studies have shown that in laparoscopic Nissen fundoplication, children are well managed with oral and rectal analgesia postoperatively. The need for postoperative high dependency and intensive care appears to be minimal.[26] Epidural analgesia may help in the prevention of painful spasms postoperatively.

ANESTHESIA FOR DENTAL PROCEDURES[27,28]

• GA is preferred for young patients who require extensive dental treatment and who do not achieve desired results with the use of local anesthesia and behavior management

• Patients with a physical/psychological disability, characterized by poor oral hygiene, soft and cariogenic diets, periodontal disease, and polypharmacy will require GA

• Medically compromised patients with an underlying disease, must undergo surgery under GA so they may be monitored better

• Intraoperative management remains same as that for other cases under GA

• Special attention must be provided to tackle problems that may arise due to defective dentition, intraoperative bleeding as well as pooled secretions

• Effort should be made to motivate CP patients and their parents to visit the dentist and receive primary prevention. There should be special programs that enhance communication between pediatric dentists and pediatricians to prevent these dental problems

• Oral health problems can be prevented by programs designed to enhance communication between the pediatrician and pediatric dentist.

CONCLUSION

The management of CP is multimodal one. The treatment in these cases demands a team therapy by psychotherapy, physiotherapy, medical, and surgical approaches. Considering the ethical aspects, the primary goal of such specialized care is mainly to improve the quality of life and the quality of care. Anesthesiologist comes into picture during the perioperative management, in high-dependency care and intensive care as well as pain management. Recent advances in treatment modalities and surgical techniques along with improved postoperative care have significantly reduced the morbidity. A successful management in CP is done by a team of experienced specialists as well as psychological support by caregivers.

REFERENCES