Information for Year 1 ITU Training (basic):

Transcription

1 Disclaimer: The Great Ormond Street Paediatric Intensive Care Training Programme was developed in 2004 by the clinicians of that Institution, primarily for use within Great Ormond Street Hospital and the Children s Acute Transport Service (CATS). The written information (known as Modules) only forms a part of the training programme. The modules are provided for teaching purposes only and are not designed to be any form of standard reference or textbook. The views expressed in the modules do not necessarily represent the views of all the clinicians at Great Ormond Street Hospital and CATS. The authors have made considerable efforts to ensure the information contained in the modules is accurate and up to date. The modules are updated annually. Users of these modules are strongly recommended to confirm that the information contained within them, especially drug doses, is correct by way of independent sources. The authors accept no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in the modules. The text, pictures, images, graphics and other items provided in the modules are copyrighted by Great Ormond Street Hospital or as appropriate, by the other owners of the items. Copyright Great Ormond Street Hospital. All rights reserved. Seizures and Status Epilepticus Written: Revised: 2006 Dr Sophie Skellett 2009 Dr Mark Peters 2015 Dr Emma Borrows + Dr Jean-Sebastien Tremblay-Roy Available Guidelines: Status Epilepticus guidelines on ICU (on K drive) Fundamental Knowledge: List of topics relevant to PIC that will have been covered in membership examinations (not repeated here). Classification Causes of neonatal seizures Indications and side effects of anticonvulsants Year 1 ITU curriculum Information for Year 1 ITU Training (basic): Emergency management of convulsive status epilepticus (CSE) ICU Management of Seizures Curriculum Notes for Year 1: Convulsive status epilepticus (CSE) is defined as recurrent or continuous seizure activity lasting longer than 30 minutes in which the patient does not regain baseline mental status. The estimated incidence of CSE in childhood is between 17 to 23 episodes per 100,000 per year. Incidence rates, causes, and prognosis vary substantially by age. The highest incidence is in the first year of life. Febrile status epilepticus is the most common aetiology. About 60 % of children are neurologically healthy prior to the first episode of CSE. Between % of children with epilepsy will have at least one episode of CSE. CSE occurs as the first seizure in 12% of children with epilepsy. (1-3) CSE may also present as an acute symptom of medical or neurological disease including central nervous system infections (meningoencephalitis), acute hypoxic ischaemic insult, metabolic disease (hypoglycaemia, inborn error of metabolism), electrolyte imbalance, traumatic brain injury, drugs, intoxication, poisoning, and cerebrovascular event.

2 Systemic complications often accompany CSE and contribute to associated morbidity and mortality. These include hypoxaemia, acidemia, glucose alterations (often high initially then low if prolonged), increased intracranial pressure, raised WCC, elevated body temperature and blood pressure disturbances There will usually be a raised BP and HR at start of CSE due to massive release of catecholamine and sympathetic discharge. If seizure persists blood pressure decreases and may result in hypotension, Mortality 3-11% dependant on underlying aetiology. (2.3) Emergency management of seizures and status epilepticus: Any seizure lasting more than 5 minutes or repeated seizures (three or more in an hour) requires prompt intervention. Aims of management: Ensure adequate cardiorespiratory function Correct and prevent metabolic imbalance of hydration, electrolytes, glucose and lactate Aim for euvolaemia and do not overhydrate because of the risks of Syndromes of Inappropriate Antidiuresis (SIADH) and cerebral oedema Terminate seizure activity Treat recurrent seizures promptly and prevent further seizure activity Evaluate for and treat specific causes Emergency Management of convulsive status epilepticus (NICE guideline CG137): (4) Time Seizure starts Confirm clinically that it is an epileptic seizure 0 mins (1 st step) 5 mins (2 nd step) 15 mins (3 rd step) Check ABC, high flow O 2 if available Check blood glucose Midazolam 0.5 mg/kg buccally or Lorazepam 0.1 mg/kg if intravenous access established Lorazepam 0.1 mg/kg intravenously Midazolam may be given by parents, carers or ambulance crew in non-hospital setting This step should be in hospital Call for senior help Start to prepare phenytoin for 4 th step 25 mins (4 th step) 45 mins (5 th step) Phenytoin 20 mg/kg by intravenous infusion over 20 mins or (if on regular phenytoin) Phenobarbital 20 mg/kg intravenously over 5 mins Rapid sequence induction of anaesthesia using thiopental sodium 1-3 mg/kg intravenously Re-confirm it is an epileptic seizure Paraldehyde 0.8 ml/kg of mixture may be given after start of phenytoin infusion as directed by senior staff Inform intensive care unit and/or senior anaesthetist Transfer to paediatric intensive care unit When the protocol is initiated it is important to consider what pre-hospital treatment has been received and to modify the protocol accordingly (there is a significantly increased risk of respiratory depression and unnecessary referral for ICU with more than 2 total doses of benzodiazepines).

3 ICU management of seizures: Avoid / discontinue any muscle relaxants used for transfer in order to observe any ongoing / recurrence of seizure activity. Management of further Seizures (5) : 1. Re-check blood glucose, and electrolytes and correct if needed 2. Bolus benzodiazepines to terminate seizure a. Lorazepam mg/kg iv/io (rapid onset and long duration of anticonvulsant action 4-6 hours) b. Midazolam mg/kg iv (slightly slower onset of anticonvulsant action, shorter half life) 3. Midazolam infusion a. Often already on a midazolam infusion for sedation, if not consider starting b. Increase rate for seizure control (slower effect than giving bolus dose) 4. Phenytoin and phenobarbitone a. Check levels b. Consider further loading or half loading dose i. Phenytoin 20 mg/kg iv/io slow infusion to avoid hypotension / cardiac arrhythmias ii. Phenobarbitone 20 mg/kg iv/io (particularly effective for neonatal and febrile status epilepticus) 5. Thiopentone a. Bolus dose (1-3 mg/kg) consider using to gain control acutely while waiting for longer acting medication to control the underlying seizure tendency b. Infusion i. Only start after discussion with consultant intensivist ii. Aim is to suppress electrical correlates of seizure activity and induce burst suppression iii. Thiopentone 1-3 mg/kg loading dose, preferably with EEG recording. iv. Maintenance infusion 1-8 mg/kg/hour via a central line giving the minimum required to achieve aim v. Anticipate need for increased cardiovascular support with both intravascular filling and inotropes 6. Other anaesthetic agents may be employed in complex cases. Investigations / treatment: Consider aetiology and investigate / treat appropriately. Early involvement of neurology team. Aetiology tends to vary depending on the age of the child and includes: Febrile convulsions For fits associated with fever typical of febrile convulsions ask about family history and look for source infection. Note this may be complicated by two factors: firstly if CSE continues for long enough it can cause hyperthermia and secondly the white cell count is not usually a guide to infection as it will be raised in either scenario, returning to normal after hours Pre-existing seizure disorder If patient is a known epileptic on medications continue current antiepileptics (unless suspicion of overdose), check anticonvulsant levels, any recent change in medications, or intercurrent illnesses In complex cases consult a neurologist CNS infection Risk of meningo-encephalitis treat with antibiotics (age dependant) and aciclovir until CSF can be examined. Neonates cefotaxime, amikacin, ampicillin and aciclovir 1-3 months cefotaxime, amikacin, ampicillin and aciclovir (consider clarithromycin) >3 months cefotaxime, clarithromycin and aciclovir

4 Raised intracranial pressure secondary to space occupying lesions / hydrocephalus / intracranial haemorrhage First seizure with any focal element arrange a CT scan brain if has not already been done Check if patient has an intraventricular shunt which may have become blocked or infected urgent CT Patients examination looking for lateralizing neurological features, papilloedema Neurosurgical consult Intracranial haemorrhage with no clear mechanism consider NAI and look for other signs (will need skeletal survey and ophthalmology review for retinal haemorrhages) Electrolyte abnormalities May be secondary to metabolic disorders causing hypoglycaemia Toxins / Drugs Topical anaesthetic agents, anti-epileptic overdose, cocaine, nicotine, hypoglycaemic agents (insulin), tricyclic antidepressants Take early urine sample for toxicology, it can always be discarded later if not necessary Hypoxic injury / Birth injury Epilepsy syndromes Febrile Infection Related Epiliepsy Syndrome (FIRES) Lennox-Gastaut syndrome Retts syndrome West syndrome Epidemiology of First Ever CSE in Childhood In a population based study (North London Status Epilepticus in Childhood surveillance study NLSTEPSS), the precipitating causes of 226 episodes of childhood CSE was investigated. Several important lessons come from this landmark paper in Lancet 2006 (1) Incidence is between episodes per 100,000 children per year The death rate from a first episode of CSE is 3% (95% CI 2-7%) similar to infant respiratory failure requiring intubation. This is not a trivial condition. 12% of first ever cases of CSE occurred in the context of acute bacterial meningoencephalitis. 1 year recurrence risk was estimated at 16% (10-24%) Only 57% of cases of first ever CSE could be ascribed to a prolonged febrile seizure.

5 Year 2 ITU curriculum: Information for Year 2 ITU Training (advanced): Newer considerations in acute management of CSE observational study of 182 children presenting with 240 episodes of CSE in North London (6) found: The use of iv. lorazepam is associated with a 3.7 times (95% CI ) greater likelihood of seizure termination than rectal diazepam Treatment with intravenous phenytoin as a second line therapy was associated with a 9 times (95% CI 3 27) greater likelihood of seizure termination than was treatment with rectal paraldehyde. No treatment pre-hospital and more than 2 doses of benzodiazepines (OR 3.6, ) were associated with episodes that lasted for more than 60 minutes. Treatment with more than 2 doses of benzodiazepines was associated with respiratory depression (OR 2.9, ) Each 1 min delay in emergency admission was associated with a 5% cumulative increase in risk of the episode lasting more than 60 minutes. For these reasons it is appropriate to consider more aggressive frontloading of the therapy for CSE than the current guidelines indicate. Febrile infection-related epilepsy syndrome (FIRES) (7) 1. Definition: FIRES describes a syndrome of acute onset of severe refractory status epilepticus or multiple seizures per day for >1 week following a febrile illness but without clear evidence of meningoencephalitis or other infectious, metabolic or inflammatory etiology. The seizure type at the onset of the syndrome is mainly partial seizure or secondarily generalized. The mechanism is unclear and the infectious agent is often not identified. 2. Investigation: Usual investigation of status epilepticus. Results are non-specific and show few cells in the CSF, negative polymerase chain reaction, and no oligoclonal bands in the protein electrophoresis of CSF. Auto-antibodies are usually negative (like anti-nmda antibodies). MRI is often negative or can show bulging of the mesial temporal structures during the first weeks of the disease, with T2 hypersignal. 3. Treatment: a. No anti-epileptic drugs seems to decrease the seizure load or reduce the duration of the disease. b. Ketogenic diet seems to be one treatment option that have some effect for some children. c. IVIG and steroid can be an option but doesn`t appear to be very effective. More vigorous or chronic immunomodulation therapy should be considered when there is a positive response. d. Utilisation of burst-suppression coma is associated with poorer cognitive level at follow-up in one retrospective study. This association should be considered cautiously, since induction of a longer BSC state is also the result of a longer disease process and thus likely to reflect a more severe condition. 4. Morbidity/Mortality: Death rate between 5 and 30%. Long term epilepsy and cognitive disability are frequent (>50%) if the patient survives. Other sources of information: Websites. 1 British paediatric neurology association website: 2 At least 2 useful emedicine papers i. on neonatal seizures ii. on status epilepticus

6 References 1. Chin RF, Neville BG, Peckham C, Bedford H, Wade A, Scott RC; NLSTEPSS Collaborative Group. Incidence, cause, and short term outcome of convulsive status epilepticus in childhood: prospective population based study. Lancet Jul 15; 368(9531): Verity C. Do seizures damage the brain? The epidemiological evidence. Arch Dis Child 1998;78: Lacroix J, Deal C, Gauthier M, Rousseau E, Farrell CA. Admissions to a pediatric intensive care unit for status epilepticus: a 10year experience. Crit Care Med May;22(5): NICE guidelines [2012] The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care [CG137]. Available at 5. Appleton R, Choonara I, Martland T, Philips B, Scott R, Whitehouse W. The treatment of convulsive status epilepticus in children. Arch Dis Child 2000;83: Chin RF, Neville BG, Peckham C, Wade A, Bedford H, Scott RC. Treatment of community onset, childhood convulsive status epilepticus: a prospective, population based study. Lancet Neurol Aug; 7(8): Kramer U, Chi C-S, Lin K-L, Specchio N, Sahin M, Olson H, et al. Febrile infection-related epilepsy syndrome (FIRES): Pathogenesis, treatment, and outcome: A multicenter study on 77 children. Epilepsia. Nov 2011;52(11):