MND Study Day. Martin Latham CNS Leeds Sleep Service

Transcription

1 MND Study Day Martin Latham CNS Leeds Sleep Service

2 Objectives: Identifying individuals at risk. Understand issues related to NIV. Understand issues related to secretion management Improve outcomes.

3 Identifying those at risk: At risk individuals have: Vital capacity less than 50% predicted. Resting SpO 2 less than 95%. Low sniff / mouth pressures. Become dyspnoeic when lying flat. Sleep disordered breathing.

4 Nice Guidance: Forced vital capacity (FVC) or vital capacity (VC) FVC or VC less than 50% of predicted value FVC or VC less than 80% of predicted value plus any symptoms or signs of respiratory impairment (see recommendation ), particularly orthopnoea Sniff nasal inspiratory pressure (SNIP) and/or maximal inspiratory pressure (MIP) (if both tests are performed, base the assessment on the better respiratory function reading) SNIP or MIP less than 40 cmh2o SNIP or MIP less than 65 cmh2o for men or 55 cmh2o for women plus any symptoms or signs of respiratory impairment (see recommendation ), particularly orthopnoea Repeated regular tests show a rate of decrease of SNIP or MIP of more than 10 cm H2O per 3 months

5 Sleep: a game of 2 parts Sleep can be divided into 2 distinct forms: a) Non Rapid Eye Movement (NREM) sleep b) Rapid Eye Movement (REM) or Dream sleep

6 Breathing changes in sleep: Becker H. et al (1999) Breathing during sleep in patients with nocturnal desaturation. Am J Respir crit care med 159, pp

7 Screening for Sleep Disordered Breathing: Early referral to sleep service. Overnight Oximetry Easy to use. Widely available. Needs to be downloaded. Characteristic patterns in nocturnal hypoventilation.

8 Oximetry showing Nocturnal hypoventilation: 100% 90% Saturation 80% 70% 60% Pulse 50%

9 Has oxygen got a role? Marcus, C.L. (2001) Sleep disordered breathing in children. Am J Respir crit care med.164, pp

10 Initiating NIV: Advanced preparation of patient: Patient requests NIV? NIV mentioned before needed. Seen or met other users? Frank and open discussion of pros & cons. Short to medium term gains. Long term losses. Advance directives

11 Progression of NIV in MND: Night time only Mask ventilation < 10 / 24 hours Night time + some day time Mask Ventilation / 24 hours Ventilator dependant Mask ventilation > 14 / 24 hours Ventilator dependant Tracheostomy ventilation > 14 / 24 hours

12 Problems with mask ventilation: Headgear Mask type Circuit weight Pressure sores

13 Pressure sores: Don t always occur where you expect them to!

14 Mask fit is everything Poor mask fit can affect the quality of sleep and the efficacy of NIV.

15 Recent new designs Mask update

16 Hot off the press Brill et al (2018) found higher nasal bridge pressures with gel rather than silicone masks Masks had lower pressures in supine position IPAP did not influence nasal bridge pressure Brill et al (2018) Mask pressure effects on the nasal bridge during short-term non-invasive ventilation. ERS Open Res Apr; 4(2):

17 Secretion Management Thanks to Lisa Emmett physiotherapist for this part of the presentation

18 Secretion Management Why is secretion management so important? 90% of patients with NMD die as a result of a respiratory tract infection and inability to clear secretions effectively (Bach et al, Am J Phys Med Rehabil 1998, 77)

19 Requirements for an Effective Cough: Vital capacity volumes in excess of litres Expiratory muscle strength to generate thoracoabdominal pressure in excess of 100 cmh 2 0 Intact glottis control Bach 1993, Dean and Bach 1996,Whitney et al 2002, Bach 2003

20 Cough Peak Flow An assisted cough peak flow (CPF) of >160l/min (2.7l/sec) is required for secretion clearance (Bach and Saporito, Chest 1996) URTI further reduce the CPF making those who are normally above this level but <270l/min regarded as at risk A normal CPF ranges from l/min

21 Cough Peak Flow The greater the cough peak flow, the less likely are respiratory complications of neuromuscular disease (Bach, Ishikawa and Kim, Chest, 1997, 112) Red CPF < 160 lpm Amber CPF lpm Green CPF > 270 lpm

22 Lung volume recruitment Breath stacking Technique of increasing breath size by sniffing a little more air in on top of a normal breath. Holding the extra air in and sniffing again and again. Huff on exhalation.

23 Lung volume recruitment Modified resuscitation bag with one-way valve incorporated. User can breathe in but not out! Mouth piece or mask. Treatments should be breaths x 3 day.

24 Lung volume recruitment Clears sputum, preventing retention, atelectasis and their associated problems Maintains compliance of thorax Maintains length of respiratory muscles Preserves strength of cough Reduces hospital admissions Increases survival Improves quality of life

25 Mechanical in-exsufflation (cough assist) Is the only treatment which both increases inspiratory volume and increases expiratory flow It delivers gradual positive inspiratory pressure followed by a rapid shift to negative expiratory pressure simulating a cough

26 Cough peak flow Unassisted Breath stack Manual assisted cough Mech In-Ex 1.81 l/sec 3.37 l/sec 4.27 l/sec 7.47l/sec (108 l/min) (202 l/min) (252 l/min) (448 l/min) Bach Chest 1993

27 Cough is important! An effective cough requires both inspiratory and expiratory muscle power plus rapid and firm closure of the glottis Hence people with respiratory muscle weakness and especially those with bulbar symptoms are at risk of retained secretions Needs consideration sooner rather than later Prophylaxis is definitely to be recommended

28 After thought House Spiders: How will that cup of coffee affect your sleep? R Noever, J Chronise & R Relwani; Using spider-webs patterns to determine toxicity. NASA (1995) Tech Briefs 19:4 pp82.