Anaesthesia for cebral palsy
- 1. ANAESTHETIC MANAGEMENT OF PATIENTS WITH CEREBRAL PALSY Dr. Ashraf Arafat Abdelhalim, MD Professor of anesthesia Department of Anesthesia, Faculty of Medicine, Alexandria University, Egypt
- 2. INTRODUCTION • Cerebral palsy (CP) is a group of non-progressive disorders of motion and posture. It results from injury to the developing brain during the antenatal, perinatal or postnatal period. • Recognised risk factors for developing CP include: perinatal hypoxia, prenatal infection, congenital abnormalities, trauma, and genetic predisposition. • Clinical manifestations are related to the area of central nervous system (CNS) affected. • The clinical picture may vary considerably, from high functioning mild monoplegia with normal intellect to severe spastic quadriplegia with mental retardation.
- 3. Swedish Classification for CP (complex cases may defy classification) Spastic • 70% (most common clinical manifestation) • Quadriplegia 27% of all cases of CP • Diplegia 21% • Hemiplegia 21% Dyskinetic • 10% (often normal intellect but difficulties with communication) • Dystonia (maintained twisting position of torso and extremities) • Athetosis (slow, purposeless, distal movements) • Chorea (quick, jerky, proximal) Ataxic • 10% • Intention tremor and head tremor (titubation) Mixed • 10% • e.g. spastic athetoid
- 4. COMMON SURGICAL PROCEDURES: • 60% Orthopaedic procedures: major multilevel surgery involving tenotomies/osteotomies, soft tissue release/tendon transfers, and botulinum toxin injections. • 10% Dental extractions and restorations. • 10% Gastrostomy and anti-reflux procedures. • 10% Imaging. • 10% Other: neurosurgery, urology, ophthalmology, ENT and insertion of infusion devices.
- 5. CLINICAL PROBLEMS AND COMORBIDITIES Central nervous system • Epilepsy affects approximately 30% of CP patients, and is most common in spastic hemiplegia. • Tonic clonic and complex-partial seizures are common. • Anticonvulsants should be continued throughout the perioperative period. • Understanding anticonvulsant side effects and drug interactions is important. • Visual (40%) and hearing deficits, behavioral disorders, communication problems and intellectual impairment are all common. • Up to 60% of hemiplegic patients have normal intelligence. • Communication aids may be required. • Attention deficit hyperactivity disorder (ADHD) is common in the higher functioning child. • Depression and emotional lability are common in adolescents.
- 6. Cardiovascular: • Vascular access may be made difficult by multiple previous cannulations, scars, contractures of upper limbs, communication problems or behavioral issues. • Features suggestive of coexisting congenital heart disease should be looked for. • Chronic lung disease may lead to pulmonary hypertension, right ventricular hypertrophy or cardiac failure. • Cardiopulmonary exercise tolerance cannot be properly assessed because of neurocognitive impairment and poor communication.
- 7. Respiratory: • Respiratory disorders are ultimately a common cause of death including pulmonary aspiration, recurrent respiratory infections and chronic lung disease, poor cough with retention of secretions, poor nutritional state and impaired immunity. • Scoliosis with restrictive lung defect may lead to cardiopulmonary compromise. • Pre-operative physiotherapy, bronchodilators or antibiotics may be required. • The airway should be assessed for potential difficult laryngoscopy due to poor dentition, TMJ dysfunction and positioning problems. • Review of previous anesthetic charts may be helpful.
- 8. Gastrointestinal • Gastro-oesophageal reflux is common due to oesophageal dysmotility and spasm, abnormal lower oesophageal sphincter function and spinal deformity. • Reflux is difficult to detect and night wakening may be the only indicator. • Salivary drooling due to pseudobulbar palsy may occur with impaired swallowing. • Tongue thrusting and poor head movements further contribute to difficult airway management. • Poor oral feeding may lead to dehydration, failure to thrive, malnutrition, electrolyte imbalance and anemia. • Preoperative nasogastric feeding or gastrostomy may be required.
- 9. Airway assessment • Should be assessed for potential difficult laryngoscopy because of an increased incidence of dental caries, loose teeth and temporomandibular joint dysfunction. • Children with CP and autism have a high incidence of malocclusion probably due to tongue thrusting. • Adenoid hypertrophy can be suspected and confirmed if the patient has a history of nasal obstruction. • Adenoidectomy should be done prior to further surgical intervention. Franklin DL, Luther F, Curzon ME. The prevalence of malocclusion in childrenwith cerebral palsy. Eur J Orthod 1996;18:637e43.
- 10. Allergies: • Latex allergy has been reported in CP patients, probably due to repeated exposure during multiple operative procedures. • A history of such sensitivity must be noted and taken seriously. Medications • Medical therapy for controlling seizures, spasticity, reflux, constipation and depression should be well understood, • Particularly side effects and potential interactions.
- 11. Common drug groups encountered in patient with CP are anticonvulsants, antispasmodics, anticholinergics, antireflux agents, antacids, laxatives and antidepressants. • Carbamazepine : Induction of hepatic enzymes, reduced duration of action of vecuronium. • Sodium valproate: Impaired platelet function, increased risk of bleeding, hepatotoxicity, bone marrow suppression. • Newer anticonvulsants like levetiracetam are relatively free of adverse effects and can be continued as i.v. infusion in the intraoperative period, however, anaesthetic implications pertinent to its use have not been established. • Dantrolene (oral): Muscle weakness, malaise, nausea, diarrhoea, skin rash, abnormal LFT’s. Benzodiazepines: Sedation, respiratory depression, dependence • Clonidine has been shown to reduce tone and improve spasticity in patients not responding to diazepam or baclofen.
- 12. • Baclofen: GABA-Breceptor agonist : It is used to reduce pain associated with muscles pasms and may delay the development of contractures. Overdose causes drowsiness, respiratory depression, rostral progression of hypotonia. Occasional bradycardia and hypotension during GA, and delayed arousal after GA. Abrupt cessation may cause seizures, hallucinations, disorientation, dyskinesias and itching, with symptoms lasting up to 72 h. Hence, these drugs should be continued in the perioperative period.. - Gomar C, Carrero EJ. Delayed arousal after general anesthesia associated with baclofen. Anesthesiology 1994;81:1306e7. • - Bradycardia and hypotension associated with baclofen used during general anesthesia. Anesthesiology 1986;64:255e8. Botulinum toxin • BoNT/A produces reversible muscle denervation leading to a temporary reduction in muscle tone. • In children with muscle weakness due to botulinum toxin injection, the effects of muscle relaxants may be potentiated. Systemic advers eevents following botulinum toxin A therapy in children with cerebral palsy. Dev Med Child Neurol 2010;52:139e44.
- 13. PERIOPERATIVE MANAGEMENT Perioperative challenges: • Seizure control, • Optimization of respiratory function, • Gastrooesophageal reflux, • Management of pain, • Muscle spasm, • Nausea/vomiting • Effective communication.
- 14. Pre - operative • Patient anxiety is common and may be exacerbated by poor understanding and communication difficulty. • It can be useful having the primary carer with the patient at induction, in recovery and during the postoperative period. • Parental anxiety and even aggression. • Parents should be consulted about the child’s previous experience with sedation or general anesthesia and previous records studied. • Respect and good communication is vital. • Consent for any procedure needs to be clearly informed with risks and benefits.
- 15. • It is prudent to avoid sedative premedication in patient with CP who are predominantly hypotonic.10 Loss of airway tone and increased risk of aspiration is greater in hypotonic patient. • Reducing the dose may be more appropriate than omitting premedication altogether. • Patients may be severely affected by drooling because of decreased ability to swallow secretions, making gaseous induction of anesthesia both messy and risky. • Anticholinergics like glycopyrrolate may be beneficial by drying oral secretions but may increase the risk of chest infection by thickening lung secretions. • Local anesthetic cream should be used at the venepuncture site to reduce pain and distress. • Antireflux medication should be continued. • Concurrent medication like antiepileptics and antispasmodic drugs should be continued till the morning of surgery . Theorux MC, Akins RE. Surgery and anesthesia for children with cerebral palsy. Anesthesiol Clin N Amer 2005;23:733e43.
- 16. Intra operative • Monitoring should be according to the national safety standard. Temperature monitoring is particularly useful as CP patients are vulnerable to hypothermia, particularly in long procedures. • Monitoring depth of anaesthesia may be beneficial as the MAC value is variably decreased. • Neuromuscular monitoring isuseful as CP patients have altered responses to muscle relaxants. • Vascular access may be difficult and use of ultrasound may not be possible in the uncooperative child. • A second anaesthetist is often helpful to help establish IV access. • Dehydration from abnormal cognitive responses to thirst and prolonged fasting should be assessed and managed appropriately.
- 17. • Induction of anesthesia may be challenging due to lack of cooperation, communication problems and difficult intravenous ( i.v.) access. • Airway maintenance may be complicated by excessive secretions and reflux. • Suction of the oro- or naso-pharynx may help clear excessive secretions. • The benefits of rapid sequence induction (RSI) versus gas induction in an uncooperative child must be balanced. • Wongprasartsuk P, Stevens J, Cerebral palsy and anaesthesia, Paediatric Anaesthesia 2002; 12:296-303.
- 18. • ETT size should be selected based on age, with respect that most children with CP are small for their age. • Positioning may be difficult due to fixed contractures, and must be done with extreme care to avoid nerve damage, muscle damage and pressure ulcers. • Prevention of pressure ulcers is required, especially in patients receiving epidural analgesia, prolonged immobilization, and in malnourished children. • Gibson P R J, Anaesthesia for correction of Scoliosis in Children, Anaesthesia & Intensive Care 2004; 32: 548-559
- 19. • Temperature regulation is an important issue in CP children. • Hypothermia is common due to disordered temperature regulation from hypothalamic dysfunction, lack of insulating muscle and fat and malnourishment. • Normothermia may be difficult to achieve despite use of forced air warmers, warmed intravenous fluids and warmed irrigating fluids. • Warm humidified gases are beneficial.
- 20. Drug responses are altered: • For volatile agents, (MAC) is reduced compared to controls. • MAC of halothane is 20% lower in children with CP and a further 10% lower in those currently taking anticonvulsants. • Narcotics appear to have greater potency in CP. Doses need to be reduced, • Avoid epileptogenic agents such as enflurane, etomidate, methohexitone, ketamine, and pethidine (norpethidine accumulates in renal failure). • Tramadol lowers seizure threshold and is therefore best avoided. • There is resistance to nondepolarising muscle relaxants, due to a combination of drug interaction with anticonvulsants (increased hepatic clearance, acetylcholine receptor up regulation) and chronic immobilization. • Neuromuscular monitoring (with train of four) in a severely affected limb may underestimate the extent of NM block.
- 21. • Theroux and colleagues demonstrated increased sensitivity towards succinylcholine in these patients. • They found that the effective dose (ED) of succinylcholine to depress 50% of baseline twitch (ED50) is less in these children when compared with healthy children. • Approximately 30% of these children were reported to have extrajunctional acetylcholine receptors. - Theroux MC, Brandom BW, Zagnoev M. Dose response of succinylcholine at the adductor pollicis of children with cerebral palsy during propofol and nitrous oxide anesthesia. Anesth Analg 1994;79:761e5 • - Suzuki T, Nakamura T, Saeki S, Ogawa S. Vecuronium induced neuromuscular blockade in a patient with cerebral palsy and hemiplegia. Anesth Analg 2000;91:492e3.
- 22. Regional techniques • Regional techniques are strongly recommended for intra- and post-operative analgesia in most major procedures. • Epidural analgesia is excellent for extensive lower limb surgery, but requires an experienced operator as scoliosis and prior back surgery may make insertion challenging. • Any regional infusion must be carefully monitored by an experienced acute pain team and specialised nursing staff. Nolan J, Chalkiadis GA, Low J, Olesch CA, Brown TC. Anaesthesia and pain management in cerebral palsy. Anaesthesia 2000;55:32e41.
- 23. Post operative • Emergence problems are common. • Delayed emergence may be due to hypothermia or residual volatile agent (reduced MAC and possibly MAC awake) or due to increased sensitivity to sedatives and hypnotics.. • Excessive secretion, regurgitation and vomiting, especially in children with pseudobulbar palsy, can complicate airway maintenance. • Careful protection of the airway and frequent suctioning is therefore required. • Irritability on emergence from anesthesia is common in children • with neurocognitive disabilities. • Presence of parents or primary carer may help to comfort the patient. • Postoperative nausea and vomiting is very common, and anti-emetics should be considered particularly if opioids are used. Gomar C, Carrero EJ. Delayed arousal after general anesthesia associated with baclofen. Anesthesiology 1994;81:1306e7.
- 24. • Pain assessment can be difficult in the CP patient. • Behavioral indicators such as face grimacing, or altered sleep patterns may be present in the non- pain state and can be inconsistent and difficult to interpret. • Behavioural indicators are diverse and lack sensitivity. • The primary caregiver usually understands the child’s personality and is an invaluable resource when assessing the child postoperatively. • Surgical pain must be differentiated from benign causes such as hunger, anxiety, and positioning discomfort and muscle spasms.
- 25. • Epidural blockade is beneficial for extensive lower limb orthopaedic surgery as it can treat pain &reduce spasm. • Intrathecal opioid administration is better than systemic opioids alone for correction of scoliosis. • A multimodal approach should be used including local anaesthetic techniques, paracetamol, and anti-inflammatory drugs. • Systemic opioids may be given by (PCA) or nurse initiated analgesia (NIA). • Modification of the press button mechanism is often required. • Any continuous regional or intravenous analgesic infusions should be managed in appropriate high dependency unit
- 26. SPECIFIC PROBLEMS • Regular oral anticonvulsants should be continued. • Children with CP who suffer from epilepsy may be unable to have orally administered anticonvulsants if they are nil by mouth or experiencing postoperative nausea and vomiting. • Other than benzodiazepines, phenytoin and phenobarbitone, anticonvulsants cannot be administered intravenously. • Patients may require I.V. anticonvulsant cover if over 24 hours without oral intake is expected, particularly in children with a history of generalized convulsions. • Severe muscle spasms are frequent after lower limb orthopaedic surgery. This is caused by spinal reflexes initiated by pain.
- 27. SPECIFIC PROBLEMS • Baclofen should be continued, as acute withdrawal may lead to seizures and hallucinations. • Diazepam (oral, IV or rectal) may be given with appropriate ward monitoring until regular oral medication can be recommenced. • Beware of excessive sedation and respiratory depression when benzodiazepines are used in combination with opioids. • Diagnosis of compartment syndrome maybe delayed by regional analgesics and impaired communication. • Splitting plaster casts and leg elevation reduces this risk. Vigilant observation is required. • Fixed contractures, prolonged pressure over bony prominences and malnutrition may lead to skin breakdown. • Meticulous pressure care and frequent repositioning is required to prevent pressure sores.
- 28. SPECIFIC PROBLEMS • Chronic pain requires a multidisciplinary approach particularly useful in adolescent CP patients with normal intelligence that may suffer from depression. • Differentiation of surgical pain from other causes of pain is important. • Hip subluxation causing pain on transfer; • Reflux causing night waking; • Back pain from prolonged sitting; • Period pain associated with menstruation; and painful spasticity all requiredifferent modes of therapy. • Nolan J, Chalkiadis GA, Low J, Olesch CA, Brown T C K. Anaesthesia and pain management in cerebral palsy. Anaesthesia 2000; 55, 32-41.
- 29. SPECIFIC PROBLEMS • Perioperative chest physiotherapy will help those with poor cough, poor secretion clearance, and recurrent chest infections. • Patients with poor respiratory function may need postoperative ventilation and even tracheostomy during the weaning process. • Preoperative respiratory function tests are unreliable and not predictive of outcome. • C.P children are prone to constipation because of reduced gut motility and fluid intake, and perioperative opioids. • Use opioid sparing analgesia where possible and consider normal bowel habits for that child. • The prescription of laxatives may be necessary.
- 30. Conclusion • Understanding of the clinical problems associated with different types of Cerebral Palsy and their drug therapy. Preoperatively: optimise respiratory function, seizure control, gastro-oesophageal reflux disease and nutrition. Intraoperatively: prevent aspiration, hypothermia, pressure ulcers, nausea/vomiting, muscle spasm and pain. Postoperatively: Vigilance during extubation ,appropriate pain assessment with prevention of muscle spasms, contractures, chest infections, pressure sores, constipation and malnutrition.