Emergency anaesthesia and airway information for Hurler syndrome
People with Hurler syndrome (severe mucopolysaccharidosis type I, MPS I-H) have a very high risk of complications during sedation and general anaesthesia. This is due to a combination of difficult airway anatomy, cervical spine disease, heart and lung problems and obstructive sleep apnoea. These risks are present even in patients who have had haematopoietic stem cell transplantation (HSCT) or long-term enzyme replacement therapy (ERT).
This page gives concise emergency information for families, emergency teams and anaesthetists, and should always be used together with local policies and up to date difficult airway guidelines, not as a stand-alone protocol.
Important Disclaimer
This information is for healthcare professionals and families. It does not replace specialist advice, national guidelines or local protocols. In an emergency, follow your hospital's difficult airway and resuscitation guidance and involve senior anaesthetists early.
At a glance: key emergency messages
If this patient needs urgent anaesthesia or airway management:
- Treat as a high-risk, potentially impossible airway until proven otherwise.
- Assume possible cervical spine instability and limited neck movement; avoid forceful neck extension.
- Expect difficult bag-mask ventilation and intubation due to macroglossia, narrowed upper airway, reduced mouth opening and short neck.
- Use a senior anaesthetist with difficult airway experience and have advanced airway devices and front-of-neck rescue available, in line with ASA/DAS difficult airway guidelines.
- Anticipate underlying cardiomyopathy, valvular disease and restrictive lung disease; monitor carefully and be cautious with fluids and anaesthetic depth.
- Consider need for postoperative ICU or HDU and possible delayed extubation, especially after major surgery or in patients with severe airway or respiratory disease.
Where feasible, contact the patient’s metabolic or transplant centre and previous anaesthetic team for advice.
Information for families to share with emergency teams
In any emergency where your child or relative with Hurler syndrome:
- Needs an operation
- Needs to be put to sleep or sedated
- Needs an emergency breathing tube
tell the paramedics and hospital team immediately that they have Hurler syndrome / MPS I-H and that this condition makes anaesthesia and airway management high risk.
If possible, bring:
✓A copy of the latest clinic letter from the metabolic or transplant team
✓Any previous anaesthetic summary or letter that describes airway difficulties
✓A list of current medications and allergies
✓Details of the specialist centre that usually looks after the person
You can ask the emergency team to:
→Contact your usual metabolic or transplant centre for advice
→Ensure a senior anaesthetist is involved before any procedure that needs sedation or general anaesthesia
→Consider whether transfer to a specialist centre is safe and appropriate, if time allows
Family Reassurance: It is appropriate and helpful to raise these points firmly but politely with emergency teams. Your advocacy for your child’s safety is important and can make a critical difference in their care.
Key anatomical and medical risk factors
In Hurler syndrome, glycosaminoglycan storage affects the airway, bones, heart, lungs and brain. This leads to a cluster of features that make anaesthesia challenging:
Airway
- Enlarged tongue (macroglossia) and thickened soft tissues
- Narrow nasal passages and pharynx
- Thickened laryngeal structures and subglottic narrowing
- Limited mouth opening and temporomandibular joint stiffness
Cervical spine and skeleton
- Cervical spine instability and odontoid hypoplasia
- Short, stiff neck with kyphosis
- Restrictive chest wall and reduced lung volumes
Heart and lungs
- Valvular disease, cardiomyopathy and possible coronary involvement
- Restrictive or obstructive lung disease
- Severe obstructive sleep apnoea and chronic airway obstruction
Other factors
- Potential neurocognitive impairment and communication difficulties
- Multiple previous surgeries and possible scarred or altered airways
Important note: These problems do not disappear after HSCT or ERT, although treatment may improve some aspects of lung and cardiac function.
Assessment and preparation if time allows
In a true life-threatening emergency there may be little time, but where possible:
Clarify the diagnosis and treatments
- Confirm MPS I-H (Hurler)
- Ask about HSCT, ERT and previous anaesthetic experiences or complications
Focused airway and spine assessment
- Mouth opening, neck movement, jaw mobility
- History of snoring, sleep apnoea, previous difficult intubations
- Any known cervical spine instability, previous imaging or spine surgery
Cardiorespiratory status
- Look for signs of heart failure, valve disease, arrhythmia
- Assess baseline oxygen saturation and work of breathing
- Review recent echocardiograms or lung function tests if available
Plan location and resources
- Aim for a theatre or resuscitation area with full difficult airway kit, video laryngoscopes, supraglottic devices and front-of-neck access equipment
- Ensure experienced anaesthetists and ENT or surgical backup are available, in keeping with MPS and difficult airway guidelines
This section should repeat that local and national guidelines for difficult airways and cervical spine risk must always take precedence.
Airway planning in Hurler syndrome
From large reviews and the OrphanAnesthesia guideline for Hurler syndrome:
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1Expect a difficult airway as the default, even if the last anaesthetic was uneventful.
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2Involve a senior anaesthetist with experience in difficult paediatric or complex airways.
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3Maintain cervical spine neutrality as far as possible; avoid forceful manipulation.
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4Preoxygenate thoroughly and plan for failure of both mask ventilation and intubation.
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5Have a clearly defined plan A, B and C, including front-of-neck rescue in line with ASA and DAS difficult airway guidelines.
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6Use advanced techniques such as video laryngoscopy or fibreoptic intubation according to local experience and resources.
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7Avoid deep sedation without a secure airway in patients with severe airway obstruction or sleep apnoea.
Typical Airway Plan Structure
During and after emergency procedures
Full Monitoring
- Use ASA or national standards, with special attention to ECG, blood pressure, capnography and oxygen saturation.
Fluid and Drug Management
- Even after successful HSCT, most patients have progressive dysostosis multiplex, including kyphosis, scoliosis, hip dysplasia and genu valgum.
Extubation Planning
- Consider the risk of difficult extubation, airway oedema and residual obstruction; extubation should be planned and, in high-risk cases, may be delayed until in ICU.
Postoperative Care
- Many patients benefit from postoperative HDU or ICU observation, even after short procedures, especially if they have severe airway, cardiac or respiratory disease.
Pain Control
- Effective postoperative pain control is essential, but sedating drugs must be used carefully because of underlying respiratory compromise.
Information your specialist team can provide
Families should be encouraged to ask their metabolic or transplant centre for a personalised emergency anaesthetic letter. The page can list the elements such a letter might include:
Essential Letter Elements
- ✓Confirmed diagnosis and phenotype (for example, MPS I-H, Hurler syndrome)
- ✓Summary of HSCT/ERT history and major surgeries
- ✓Recent cardiac and respiratory status (for example, latest echocardiogram findings, sleep study results)
- ✓Previous anaesthetic experiences, including any documented difficult airway or ICU admissions
- ✓Known cervical spine imaging results and any spinal surgery
- ✓Current medications and allergies
- ✓The name and contact details of the usual metabolic or transplant centre and lead consultant
Emergency Card / Phone Lock Screen
For families: questions you can ask
Preparing for future procedures
For healthcare professionals: key principles to remember
- → Treat all patients with Hurler syndrome as high anaesthetic risk, even after HSCT or ERT.
- → Anticipate a difficult airway with potential cervical spine instability and follow national difficult airway guidance.
- → Involve a senior anaesthetist and consider early ENT or surgical backup.
- → Remember that cardiomyopathy, valve disease and restrictive lung disease are common and may be silent; monitor and manage accordingly.
- → Where time and geography allow, discuss high-risk cases with a specialist metabolic or transplant centre and consider transfer.
What to read next
Current treatments overview
Supportive care
Day to day management and symptom control
Multidisciplinary care
How the specialist team works together