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Paediatric patient with Upper respiratory tract infection. -to cancel or to proceed. Presenter: Mohd Hafiz Abd Razak Moderator: Dr Suryawan Tasref. Case:. Adik A, 1year 9months old boy, ex- prem 34weeks, underlying atopic eczema Alleged hit by wooden chair while palying with sister
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Paediatric patient with Upper respiratory tract infection -to cancel or to proceed Presenter: Mohd Hafiz AbdRazak Moderator: DrSuryawanTasref
Case: • Adik A, 1year 9months old boy, ex-prem 34weeks, underlying atopic eczema • Alleged hit by wooden chair while palying with sister • The chair fell on his face. • sustained bleeding from bilateral nostrils • Left eye swelling • Vomitting x 1 • Consolable crying • Otherwise: • No LOC • No EAR bleed • Able to ambulate well
At ED pt was diagnosed with 1.Mild head injury 2.Epistaxis (referred to ENT clinic the next morning) On 9/7/2014: Seen by ENT team at clnic decided for nasal bone reduction under GA Seen at Anaest Clinic for pre-op assessment Then 1 day before op (13/7/2014) seen by premed in-charge. Pt was well and fit for op. *difficult to assess CVS and respiratory system – pt uncooperative
In Ot: • Upon arrival, pt was crying, noted secretion from nose. • Was informed by mother that pt was having spiking temperature last night and was given meds, also having on-off cough • Unable to examine further in view of patient was unconsolable. • Pt under anaesthesia with inhalational induction – Sevoflurane and O2 • Upon induction noted difficulty to ventilate the pt • Tv not raised well, started to desaturate down to 50% • Attended stat by specialist in-charge, deepen the pt then saturation picking up • Given IV fentanyl 10mcg and Suxamethonium 10mg Intubated with cuff RAE ETT size 4.5 • Upon intubation noted tonsils were inflammed and enlarged • Post intubation given neb ventolin x 1, done ETT suction. • Then proceeded with operation. • Through out operation anaesthesia maintained with sevo/O2,air • Operation – uneventful • Able to extubate well.
Paediatric patient with Upper respiratory tract infection-to cancel or to proceed-
What is the natural history of URTI in children? • • Preschool children average 6-8 URTI per year(adult 2-4/year) • • both upper and lower airways affected • • 95% viral aetiology, self-limiting • • viral infections damage respiratory epithelium • • airway hyperreactivity persist for 6-12 weeks • • risk greatest in the 3 days after URTI • *there is no infection free period to schedule any elective • surgery.
PATHOPHYSIOLOGY OF AIRWAY HYPER-REACTIVITY • Several mechanisms of airway hyper-reactivity after URTI: - chemical mediators and neurologic reflexes. • Bronchoconstriction may be linked to the release of inflammatory mediators at the site of viral damage such as bradykinin, prostaglandin, histamine, and interleukin. • Stimulation of muscarinic M2 receptors present on vagal nerve endings usually results in inhibition of acetylcholine release. Viral neuraminidases are thought to inhibit these receptors and increase the release of acetylcholine, leading to bronchoconstriction. • Tachykininsplay an important role in smooth muscle contraction and are normally inactivated by neutral endopeptidase. • Viral infections may inhibit the activity of this endopeptidase, which results in an increased smooth muscle constrictor response to tachykinins
What are the problems anaesthetizing a child with URTI ?(adverse respiratory complications) • • bronchospasm • • laryngospasm • • breath-holding • • desaturation • • secretion →airway obstruction, atelectasis • • bacterial pneumonia • Can occur during intra-operative and post-operative period
What are the risk of URTI under GA? • overall 2-7 times increased respiratory risk in presence of URTI • 11 times if intubated (Cohen 1991) ‘A large prospective study involving 22159 children demonstrated increased incidence of intra and post operative respiratory events in symptomatic URTI patients as compared to asymptomatic children.’
What are the risk factors? • 1. Age: • • the younger the greater the risk • • infants <6 months higher risk of bronchospasm • • children <2 years higher risk for oxygen desaturation (Tait 2001) • 2. Intubation • • associated with ↑ adverse complications in URTI • • those non-intubated, URTI 9X risk than without URTI • • those intubated, URTI 11X risk than without URTI (Cohen 1991)
3.Co-morbid conditions • • Asthma • • Congenital heart diseases • 4. Airway Management • ETT > LMA > face mask • 5. Type of Surgery • • Airway surgery • • Upper abdominal surgery
Guidelines • • There is no consensus regarding the best anaesthetic management • • Main worry - potential for complications • • easy to cancel if child is overtly sick • • dilemma in grey area • • consider case by case basis • Depends on • • Elective or emergency surgery • • Minor or major surgery • • Severity - mild or severe URTI
Preoperative Assessment • • Detailed history & physical examination • • Fever, dysponea, productive cough, sputum production, nasal congestion, lethargy, • wheezing, reactive lung disease • • Laboratory tests not useful routinely • o WBC counts not necessarily raised • o Chest radiograph findings lag behind clinical presentation • • assess risk/benefit • • consider age, presenting symptoms, urgency, co-morbid conditions, type surgery, • anaesthetist’s comfort • • decision to cancel on a case by case basis
Elective surgery • • Mild URTI • • no fever, clear nasal discharge, mild cough, • • child active • can be anaesthetized for minor surgical procedure without intubation • Elective - Active infection • • fever, recent onset of purulent nasal discharge, cough, loss of appetite, lethargy • • may represent a prodrome of a more serious or infectious illness like chicken pox or • measles. • • Should be postponed
Emergency Surgery • • Aim is to minimize secretions & avoid stimulation of sensitive airway • • suction under deep anaesthesia • • adequate hydration • • humidification especially long case • • anticholinergics to reduce secretions and to attenuate vagally-mediated • hyperreactivity • • bronchodilator premedication may be useful • • avoid ETT if possible , intubate deep • • sufficient depth of anaesthesia to obtund airway reflexes • • extubate deep or awake?
When to reschedule surgery? • • no optimum time to wait before surgery rescheduled • • most reports say 3-4 weeks or at least 2 weeks after peak symptoms • • longer time not practical (2nd episode may occur) • • uncomplicated nasopharyngitis 1-2 weeks delay acceptable (Berry 1984) • • balance between need to proceed and time required for resolution of symptoms +reduced risk • • General consensus to postpone for 2-4 weeks
Laryngospasm – prevention and mx • Respiratory adverse events are one of the major causes of perioperative morbidity and mortality during paediatricanaesthesia. • Mortality associated with anaesthesiahas decreased dramatically from 6 per 10,000 in 1947-56 to 0.36 per 10,000 in 2000.
laryngospasm Laryngospasm is a protective reflex closure of the upper airway as a result of the glottis musculature spasm. It is essentially a reflex that acts to prevent foreign material entering the tracheobronchial tree. The exaggeration of the reflex may result in complete glottis closure and consequently impeding respiration which leads to hypoxia and hypercapnea.
In majority of patients, the prolong hypoxia and hypercapnea abolishes the spastic reflex and the problem is self-limiting. However in certain cases, the spasm is sustained as long as the stimulus continues and morbidity may occur such as : • cardiac arrest, • arrthymias, • pulmonary odema, • bronchospam • gastric aspiration
Incidence • The overall incidence of laryngospasm is 0.87%. • The incidence in children in the first 9 years of age is 1.74% with a higher incidence of 2.82% in infants between 1 and 3 months. • The incidence of bronchospasm in the first 9 years was 0.4%.
Cause Laryngospasm occurs during anaesthesia for 2 reasons: • a lack of inhibition of glottis reflexes because of inadequate central nervous system depression or • abnormal excitation, and increase stimulation. Ex:active URTI,ETT placement
Recognition Laryngospasm can be : • partial • complete. • Partial is recognised with the presence of inspiratory stridor (crowing- noise) and some degree of air entry. • complete with no air movement and absence of breath sounds. • In both partial and complete laryngospasm, signs of airway obstruction such as tracheal tug, paradoxical movement of the chest and abdomen are noticed. • Late signs such as desaturation,bradycardiaand central cyanosis may ensue.
Prevention • Prevention can be achieved by identifying and alleviating the risk factor. • Risk factors can be classified into 3 categories: • Patient-related factors • anaesthesia-related factors • Surgery-related factors.
Patient- related factors • The incidence of laryngospasm following general anaesthesia is inversely correlated with age. • Children with upper respiratory tract infection or active asthma have irritable airway and have a 10-fold increase to develop laryngospasm. • Airway hyperactivity may persist up to 6weeks after respiratory infection. • Passive smoking can be defined as a child that lives in the same house with someone who smoked more than 5 cigarettes per day. The increased carboxyhaemoglobin– so parents should stop smoking 48hrs before op. • History of prematurity, obesity,gastroesophagealreflux, patients with elongated uvula and history of choking during sleep • electrolyte disturbances such as low magnesium and calcium blood level
Surgery-related factors • Tonsillectomy and adenoidectomy have the highest incidence of laryngospasm (21-26%). • Other surgeries include appendicectomy, cervical dilatation, hypospadias surgery, thyroid surgery and oesophageal procedures.
Anaesthesia-related factors • Insufficient depth of during both induction and emergence predisposes to laryngospasm. • During anaesthesia including tracheal intubation, laryngospasm tends to occur after extubation. • While anaesthesia by spontaneous breathing using a facemask or laryngeal mask airway may result in laryngospasm during induction and maintenance
Prevention using drugs • The most important and substantiated drug is lignocaine. • The beneficial effects of IV lignocaine have been studied. Topical lignocaine at 4mg/kg is equally effective in preventing laryngospasm in children and neonates. • Other techniques such as 5% CO2 given 5 minutes prior to extubation and acupuncture has been described.
Management • Removal of the offending stimulus alone may be sufficient to treat laryngospasm. • Airway management includes opening the mouth, tight sealing with facemask, extending the neck with jaw lift and applying CPAP ventilation with 100% O2. • Airway management can be enhanced by two manoeuvres, (Larson’s maneuver). • The first involves placing the middle finger of each hand in the laryngospasm notchlocated between the mastoid process and the ear lobule and pressing inward on the styloidprocess. • The second manoeuvre consists of a vigorous forward pull of the mandible. This causes a painful stimulus and stretches the geniohyoid muscle to partially open the larynx.
Iv access • Propofol administered at 0.25–0.8 mg/kg i.v. can treat laryngospasm in 76.9% of cases. – not well studied(>3years old) • Succinylcholine is still considered the gold standard for treatment of laryngospasm. It can be given at 0.1–3mg/kg i.v. together with atropine at 0.02 mg/kg to avoid the possible succinylcholine-induced bradycardiaand cardiac arrest.
If the patient has no i.v. access, the first-line of treatment would be airway management using CPAP with 100% O2. • If laryngospasm persists, seek help to establish i.v. access. . • Succinylcholine may be given via one of these routes: i.m., intralingual, submentaland intraosseous. • The i.m. dose for succinylcholine is 3-4 mg/kg. The intralingual dose is 1.1 mg/kg. The submental dose is 3mg/kg.
Intravenous vs inhalational induction • Induction of anaesthesia with an inhalation agent (sevoflurane, halothane) is associated with more respiratory complications compared to induction with propofol; • induction with thiopentone is associated with the highest risk of respiratory complications. • Conversely, anaesthesia maintained with inhalational agents is associated with fewer complications compared to intravenous maintenance of anaesthesia. • There are fewer airway complications when the anaesthetist is more experienced. • Respiratory complications are higher when neuromuscular blocking agents are not reversed
Intravenous vs inhalational induction • Intravenous or inhalation techniques may be used to maintain anaesthesiaprovided anaesthesia is sufficiently deep. • Use of sevoflurane for induction and maintenance results in fewer complications compared to sevoflurane for induction and isoflurane for maintenance. • There is no consensus on the optimum depth of anaesthesia at which extubation of the trachea or removal of the LMA should be done. Many anaesthetists would prefer to remove the airway when the patient is awake to enable the patient to clear secretions and better protect the airway. • Others would argue that removal of the airway under deep anaesthesia avoids reflex airway constriction. • One study showed no difference in the incidence of complications when the ETT was removed awake or under deep anaesthesiain children with URTI
Take home message • Children with active and recent URTI (within 4 weeks) are at increased risk of perioperative respiratory complications • It is crutial to detect URTI during pre-anaesthesic assessment as it may leads to more complications. • Laryngospasm is a common and often serious adverse event encountered during the anaesthetic care of children. Identifying the patients at risk and taking the necessary precautions are the key points in preventing laryngospasm. Children pose many questions for anesthetists.