Non-invasive ventilation and home respiratory support — branching viva

Station opening

Examiner: "Define non-invasive ventilation and tell me how CPAP differs from bilevel." [2]

Strong candidate (must-hit)

• Defines non-invasive ventilation as positive-pressure support through a mask or nasal interface without an artificial airway; explains that CPAP applies one constant pressure that splints the airway and recruits the lung but does not augment the breath, whereas bilevel cycles between a higher inspiratory and a lower expiratory pressure, and that difference is the pressure support that increases tidal volume and unloads the muscles; adds that a back-up rate is needed when the child's drive is weak or absent. [2]

Weak candidate

• "It is just a breathing mask; CPAP and BiPAP are the same thing." [2]

Branch A — The boy with Duchenne muscular dystrophy and morning headaches

Examiner: "A 13-year-old with Duchenne has morning headaches and daytime sleepiness but a normal daytime blood gas. What is happening and what do you do?" [3]

Strong

• Recognises nocturnal hypoventilation, explaining that it appears first in sleep (especially rapid-eye-movement sleep) before the daytime gas changes; confirms with an overnight study measuring carbon dioxide, noting oximetry alone can miss it; starts nocturnal bilevel ventilation; and, because the cough is weakening, assesses cough peak flow and introduces mechanical insufflation-exsufflation before the next chest infection. [3] [7]

Weak

• "Give him some oxygen at night and review in a year." [3]

Branch B — The infant with bronchiolitis and rising work of breathing

Examiner: "A 5-month-old with bronchiolitis is tiring and desaturating. How do you use non-invasive support?" [10]

Strong

• Starts high-flow nasal cannula for the hypoxaemic, distressed infant, explaining that it washes out dead space and reduces the work of breathing and that the PARIS trial showed it reduces escalation of care though it does not shorten the illness; escalates to CPAP if obstruction or tiring continues; and states clearly that failure to improve, apnoeas, an unprotected airway or copious secretions mean the infant needs intubation rather than more mask time. [10] [2]

Weak

• "Non-invasive support has no role in bronchiolitis; intubate straight away." [10]

Branch C — The newborn who hypoventilates whenever asleep

Examiner: "A newborn is pink and breathing when awake but hypoventilates and desaturates every time he falls asleep. What is the diagnosis and the principle of support?" [4]

Strong

• Suspects congenital central hypoventilation syndrome, tested for PHOX2B mutations, where the failure is of automatic drive rather than airway or muscle; explains that support must therefore deliver machine-triggered breaths — bilevel with a back-up rate, or mask or tracheostomy ventilation, with diaphragm pacing in selected children — and that support is lifelong with specialist oversight of the autonomic and neural-crest associations. [4]

Weak

• "It is obstructive sleep apnoea; a bit of CPAP will fix the drive." [4]

Branch D — Preparing a child for discharge home on nocturnal ventilation

Examiner: "A child with a neuromuscular disorder is stable on nocturnal bilevel ventilation. What must be in place before discharge home?" [1]

Strong

• Describes a structured discharge: trained, competent caregivers; back-up equipment and a power plan; a written emergency plan; consumables and servicing arranged; and a multidisciplinary community and tertiary team sharing follow-up with regular re-titration as the child grows; adds attention to adherence, the growing-face effects of the interface, and, for progressive disease, advance care planning. [1] [2]

Weak

• "Send them home once the machine is set; the family will work it out." [1]

Close

Examiner: "Summarise your approach to non-invasive and home respiratory support in one sentence." [2]

Strong

• "I decide whether the problem is obstruction (CPAP), hypoventilation (bilevel) or central drive failure (bilevel with a back-up rate), confirm and titrate against a sleep study with carbon dioxide monitoring because oximetry alone misses hypoventilation, use high-flow or CPAP acutely and start nocturnal bilevel when hypoventilation appears, build in cough assist for the weak cough, and make home ventilation safe with a fitted interface, trained caregivers, back-up equipment and an emergency plan." [2] [1]