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MPS Medical Emergency Requirements

Step 1: Stabilise the neck

To avoid cervical cord injury


  • MPS patients are at a high risk of cervical cord injury, which may result in paralysis and sudden, premature death1
  • They may experience atlantoaxial instability,2–5 commonly associated with cervical cord compression and myelopathy


  • Use manual in-line stabilisation to prevent cervical spine injury1
  • Limit the degree of flexion/extension because of the possible laxity of ligaments (with or without odontoid dysplasia) and cervical stenosis1
  • Intubation: maintain the patient in a neutral position during intubation since the “sniff” position may not be possible. Use fibre-optic intubation or video laryngoscopy1
  • Maintain the rest of the spinal column in the neutral position, as compression may occur in other regions1
  • Neurophysiological monitoring is recommended for all patients undergoing prolonged procedures and/or procedures involving a spine or manipulation of the head1

Step 2: High Risk Anaesthesia

(both intubation and extubation)

Ensure sufficient space in the nose and mouth for passage of air


Respiratory failure and airway–related emergencies are a common cause of morbidity in MPS patients,1 especially during surgical interventions.6 Critical decreases in oxygen saturation may occur suddenly1

In an airway anaesthesia emergency, there may be less than 3–5 minutes to perform an emergency tracheostomy before permanent brain damage occurs7

ANY sedative can cause respiratory complications, severe hypoxaemia, and, consequently, neurological impairment1

Airway obstruction:

  • MPS patients may have obstructive sleep apnoea (OSA), increasing the risk of airway emergencies and chronic hypoxaemia8
  • Airway obstructions may cause difficulties with mask ventilation and intubation1
  • Temporomandibular joint contracture with difficulty opening the mouth, and accumulation of glycosaminoglycans (GAGs) in the tongue, oral pharynx, and larynx can impede access to the upper airway and identification of the glottis1. This may result in negative pressure pulmonary oedema, or an inability to ventilate/intubate1 or visualise the airway9
  • Serious complications may occur during extubation, including pulmonary oedema, and the need for re–intubation or emergency tracheostomy1


  • Have an otolaryngologist (ENT), preferably with MPS experience, readily available during any surgical procedure on MPS patients due to the high potential for an emergency tracheostomy1
  • Ensure the ENT is aware that performing an emergency tracheostomy is more difficult, has a higher risk and will take longer for a patient with MPS because of their shorter neck, thickened soft tissue, and the depth of their trachea1
  • Be prepared for alternative methods of intubation (e.g. fibre–optic intubation) if mask induction followed by oral tracheal intubation is unsuccessful1
  • An oral anxiolytic may reduce anxiety and increase the potential for successful fibre–optic intubation – but, if the patient falls asleep, he or she may desaturate to dangerous levels due to upper airway obstruction1
  • Have the pre–op nurse closely monitor oxygen saturation and call the anaesthesia team immediately if changes in oxygen saturation occur1
  • Provide supplemental O2 during intubation due to the potential for difficulty in ventilation and oxygenation1
  • Consider use of nitrous oxide to assist in placement of an intravenous catheter, followed by induction with midazolam or fentanyl (reversed by flumazenil and naloxone, if required)1
  • Consider placing the patient in the lateral position during induction phase if this improves their airway1
  • Use fibre–optic bronchoscopy for tracheal induction if patient has a diffcult airway5
  • Use of a laryngeal mask airway (LMA) or nasal airway has been found to improve ventilation during bronchoscopy1
  • Consider inserting a J–tipped guide–wire through the suction channel of the bronchoscope into the trachea, remove the bronchoscope and insert a ureteral dilator or airway exchange catheter over the wire, then advancing the endotracheal tube (ETT) over this to help guide it into the trachea5
  • Avoid use of muscle relaxants until endotracheal intubation is achieved1
  • Use an ETT that is 2–3 times smaller than expected based on age1
  • In order to increase oxygen delivery to the patient during fibre–optic bronchoscopy, consider advancing a short ETT into the contralateral nares to provide continuous O2 into hypopharynx. Also, attach O2 to the suction port of the bronchoscope and intermittently inject O2 from tip of fibre10
  • Ensure full reversal of the muscle relaxant and place a nasopharyngeal airway prior to extubation1
  • Perform extubation in an area with access to the full medical personnel required should the patient need immediate re–intubation or an emergency tracheostomy1
Contact MPS Specialist

Step 3: Contact MPS Specialist

Emergency Tracheostomy may be necessary


  • Difficult intubations may result in injury to the glottis, stridor, infection or airway collapse1
  • Potential for chronic hypoxaemia due to obstructive sleep apnoea (OSA)1
  • Once MPS patients are extubated, re–intubation may not be possible, creating a potential emergency1


  • Extubation should not be performed until the patient is fully awake, a leak test has been carried out and there is adequate respiratory effort1
  • Always have an experienced otolaryngologist (ENT) or paediatric surgeon in the room during all surgical procedures on MPS patients due to the high potential for an emergency tracheostomy1
Cardiac Monitor

Step 4: Maintain Cardiac Monitoring


  • Significant cardiac manifestations are reported for MPS patients11,12
  • Cardiac valve disease is the most commonly reported cardiac manifestation in MPS patients,1,11,12 increasing the risk of mortality during surgical procedures1
  • Ischaemia and cardiac arrest due to hypotension may occur13


  • Perform an ECG to identify conduction abnormalities and signs of myocardial ischemia11
  • Perform an echocardiogram to identify cardiac valve regurgitation or stenosis as well as decreased function1
  • Monitor blood pressure using intra–arterial cannulae if surgery is lengthy or high risk1

Anaesthesia and MPS

Patients with mucopolysaccharidosis (MPS) who require surgery present a significant challenge to anaesthesiologists. The high prevalence of airway and respiratory system involvement combined with cardiovascular alterations, results in high anaesthetic risk for these patients.

MPS is a group of rare diseases, but because they are progressive, those with the condition may require numerous surgical interventions throughout their lives. For each of these interventions, a comprehensive pre-anaesthetic assessment should be carried out to thoroughly examine the patient’s current condition. Paying particular attention to how MPS has affected their airway and cardiorespiratory system will help to assess risks prior to surgery and design the best anaesthetic plan.

The most important aspects affecting both the pre-anaesthesia visit and intraoperative management of MPS patients are:

  1. Airway assessment
  2. Respiratory system assessment
  3. Cardiovascular system assessment
  4. Involvement of other organs or systems
  5. Anaesthetic considerations
  6. Other considerations for surgery

Airway, Respiratory, Cardiovascular Assessments

Other considerations

Albert Sánchez Vega (2021) ‘Consideraciones anestésicas en pacientes con mucopolisacaridosis’, in Del Toro Riera, M. (ed.) Aproximación quirúrgica al paciente con mucopolisacaridosis. España: Content Ed Net, pp. 80-88.


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