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Respiratory care

Respiratory care is one of the mainstay management issues in children with SMA.

 

Why children with SMA have respiratory complications
Respiratory muscle function in SMA features very weak intercostal muscles and a relatively stronger diaphragm. The diaphragm is the primary muscle used for breathing in children with SMA type 1 or 2. In the first year of life the chest wall is very complia nt. Thus, the chest wall in children with SMA type 1 or 2 often appears collapsed and bell shaped because of a lack of opposition of the intercostal muscles against the function of the diaphragm the resulting chest wall deformities include a bell – shaped ch est and pectus excavatum. The compromised respiratory muscle function results in:

 

  • Impaired cough resulting in poor clearance of lower airway secretions;
  • Hypoventilation during sleep;
  • Chest wall and lung underdevelopment; and
  • Recurrent infections th at exacerbate muscle weakness and the integrity of the lung parenchyma.

The recommendations have been developed according to the above general principles with the goal of maintaining safety while providing timely, efficient and effective airway management

 

Homecare

 

The following recommendations are for routine care of all SMA patients (2, 3, and 4)

  1. If child is on routine inhalation therapy that should be continued at the same dosage
  2. There is no contraindication for the use of inhaled steroid therapy if they are already on it because of the pandemic (3, 4)
  3. Reliever inhaler therapy should be well stocked up; if spacer is being used then make sure a new or recent one is being used
  4. In COVID 19 children have what is called happy hypoxia, whe re the oxygen saturation’s may drop unexpectedly, without child showing any features of respiratory distress. (5, 6)
  5. Know your child’s normal /usual oxygen saturations. Till the pandemic is over monitor the oxygen saturation’s twice daily, even in absence of symptoms and fever (6 – 9)
  6. In case of fever monitor the oxygen saturations every 4 hours, more frequently if the child has any distress or cough (2, 9)

Pulse oximetry

Pulse oximetry is ubiquitously used for monitoring oxygenation. It forewarns about the presence of hypoxemia, pulse oximeters may lead to a quicker treatment of serious hypoxemia and possibly circumvent serious complications

 

Recommendations in SMA patients (1, 2, 5, 10)

  1. Do it twice a day morning and evening, keep chart
  2. Four hourly in the presence of fever and cough
  3. Deviations more than 10 percent of baseline values should be considered significant.
  4. Saturations persistently below that level requires immediate oxygen therapy till the child can be assessed.

PULSE oxime try is an important assess ment and monitoring tool for SMA types 1 and 2, be – cause the clinical presentation of respiratory distress is muted by the diffuse muscle weakness. Furthermore, the child with SMA type 1 may become visibly cyanotic before changes in respiratory rate and work of breathing. Often, during the early phase of an illness, a child with SMA type 1 or 2 may also be tachycardic. In SMA, an acute drop in pulse oximetry to

Secretion Mobilization and Clearance

  • Key to chronic management is discussion with the family regarding goals for care of their child and offering choices for care.
  • Chronic management requires teaching families techniques for supporting their child’s breathing
  • These techniques include metho ds for airway – secretion mobilization and clearance and respiratory support.
  • Secretion mobilization includes manual or mechanical chest physiotherapy with postural drainage.
  • Cough techniques include manual cough assistance and mechanical insufflation/exsuf flation with the Cough Assist (Respironics, Murrysville, PA).
  • The guideline for SMA type 1 is to perform airway clearance twice per day when the child is well, and for SMA type 2 our guideline is to perform airway clearance as needed when the child is well .
  • The cough assist machine should be used as often as needed. Children with SMA type 3 may need airway clearance postoperatively and with serious illness
  • Assisted coughing is a critical element of respiratory care for individuals with SMA and may be the only way they can cough and clear secretions.
  • Pressures should be high enough to mobilize secretions (eg , inhale and exhale pressures of at least 30 cm H2O and ideally up to 40 cm H2O).

The protocol used at the University of Wisconsin, and to be adapted for SMA patients is as follows :

  1. Cough Assist machine, 4 sets of 5 breaths, followed by oral suctioning of secretions
  2. Secretion mobilization with manual or mechanical chest physiotherapy
  3. Cough Assist machine, 4 sets of 5 breaths, and oral suctioning
  4. Postural drainage (Trendelenburg positioning) for 15 to 20 minutes as tolerated
  5. Cough Assist machine, 4 sets of 5 breaths and oral suctioning

Access to cough assist devices should be considered part of routine care of SMA children especially in the pandemic situation Three theories have been proposed to explain the improvement in respiratory status with respiratory assist devices and include resting chronically fatigued respiratory muscles, reversing microatelectasis, and altering the CO2 set point.

Home oxygen and Noninvasive ventilation (1,2,7,9) Recommendations

  • Patients already on home oxygenation and NIV should continue same
  • Any support needs to be stepped up during an inter current illness

Respiratory Support

The short – term goals of NIV include

  • Respiratory symptom relief,
  • Reduced work of breathing
  • Improved or stabilized gas exchange,
  • Optimal patient comfort,

The long – term goals of NIV include

  • Improving sleep duration and quality,
  • Maximizing quality of life,
  • Enhancing functional status, and
  • Prolonging survival.

In studies of individuals with neuromuscular weakness and chronic respiratory failure, implementation NIV results in improved PCO2 Usual indications for NIV at home include hypoventilation, as demo nstrated by decreased oxygen saturation by pulse oximetry and increased PCO2 or obstructive sleep apnea

Additional indications for NIV specific to SMA in the COVID 19 pandemic;

  • This includes respiratory failure during a viral respiratory infection (VRI).
  • Virus exacerbates SMA weakness and when combined with the associated copious respiratory secretion production,
  • Virus contributes to the risk of respiratory failure

Nebulisations

  • The current pandemic o f COVID 19 demands greater infection control precautions Nebulisers generate aerosol particles in the size of 1 – 5microns that can carry bacteria and viruses in the depths of the lung.The risk of infections transmission via droplet nuclei and aerosols may i ncrease during nebuliser treatment because of the potential to generate high volume of respiratory aerosols that may be propelled over a longer distance than that involved in natural dispersion pattern (2,3,4)
  • Nebulisers in pandemic COVID 19 infection has the potential to transmit viable SARS – COV2 VIRUS to potentially susceptible bystanders Based on available evidence WHO continues to recommend droplet and contact precautions for those people caring for COVID 19 PATIENTS .WHO continues to recommend airborn e precautions for circumstances and settings in which aerosol generating procedures and support treatment are performed according to risk assessment (3)

Nebulisers and infection transmission risk

There is some difference in opinion regarding the degree of risk from nebulisers as the aerosol generated from the device is from the medication fluid in the nebuliser chamber and not the patient One study has demonstrated aerosol stability of SARS COV – 2 but whether this is applicable to clinical situations outside laboratory conditions is unknown(4)

SCENARIO 1: IN A PATIENT WITH SMA 1.LIKELY MILD RESPIRATORY ILLNESS DUE TO ALLERGIES OR VIRAL INDUCED WHEEZE

  1. Check Spo2
  2. Salbutamol inhaler to be given via M DI 4 – 10 puffs ,with 15mins to 1,2 hr gap in between till symptoms resolve and SPO2 improves (more than 94%)
  3. Ipratropium to be given 3 doses
  4. Short course oral corticosteroids can be given
  5. NEBULISATION should be considered NEXT when the saturation’s are persistently less than 94% and worsening symptoms and altered mental state
  6. Give in a room where ventilation is good and carer should wear proper mask and move out and wait outside the room till nebulisation is over
  7. Elderly family members not to enter the room at all 8. Monitor the saturations during nebulisations

IF patient is sick enough to be admitted and needs Nebulisations then they should be shifted to a single room, and nebulisations administered .Healthcare worker, nurse and patient attendant should wear masks and goggles with face shields

SCENARIO 2; IN A PATIENT WITH SMA;LIKELY CHEST INFECTION /COULD BE COVID 19

If COVID 19 is suspected as per examination and well focused history that includes travel history and history of contact :

IF NEBULISATION IS REQUIRED THE FOLLOWING SHOULD BE MAINTAINED

  1. Patient should be in airborne infection isolation room ,preferably a negative pressure room should be created for all hospitals with isolation facilities
  2. ALL staff and healthcare workers shoul d wear full PPE that includes N95 masks and goggles ,gloves and gown and face shield
  3. All nonessential personnel should leave the room during nebulisation
  4. Some experts suggest not reentering the room for 2 – 3 hours following nebuliser administration

Sop for nebulisation in paediatric age group during covid 19 pandemic and henceforth to be considered good practice (5,6,&7)

  • Critically assess all patients and do not nebulise needlessly
  • Nebulisers which is being used for multiple patients with same tubing and mask should not be used
  • When nebulisation is being used in suspected COVID 19 patient it should not be attempted in ER unless isolation facilities and /or negative pressure room is available. Use MDI with salbutamnol till patient can be shifted
  • Full PPE (N95 mask,face shield, goggles ,gown ) to be used by healthcare workers and patient attendant ,during nebulisation of suspected COVID 19 patients and isolation procedures followed
  • Henceforth nebulisation should not be done as an OPD /ER procedure even in low risk patients as during community transmission phase the Paediatric patient may be asymptomatic but may easily transmit the infection to healthcare worker .MDI with spacers should be used where emergency relief of bronchospasm is needed. There is no evidence that nebulisation is better in delivering the drug in such patients
  • Always check the Spacer device of the patient and the mode of delivery ,use and whether proper washing of the device is being done before deciding that the child does not respond to the MDI given via spacer .Often lack of re sponse to MDI with spacers is due to improper use ,and does not necessitate switching over to home nebulisations except in select cases .
  • Where home nebulisations are being given in select cases ,the patient carer must be given appropriate training in the cleaning of the nebulisers on a regular basis

Resource :

  1. Schroth MK. Special considerations in the respiratory management of spinal muscular atrophy. Pediatrics . 2009;123 Suppl 4:S245 – S249. Doi:10.1542/peds.2008 – 2952K
  2. WHO Interim Guidance: Infection prevention and control during health care for probable or confirmedcases of novel coronavirus (ncov) infection (PDF) ( www.who.int/csr/disease/coronavirus_infections/ipcncovguidance_06May13.pdf ).
  3. https://www.who.int/news – room/commentaries/detail/modes – of – transmission – of – virus – causing – covid – 19 – implications – for – ipc – precaution – recommendations
  4. Minnesota Department of Health, Health Advisory: COVID – 19 Infection Prevention and Control inhealthcare (PDF) (www.health.state.mn.us/communities/ep/han/2020/mar13ic.pdf https://www.health.state.mn.us /diseases/coronavirus/hcp/aerosol.pdf
  5. Van Doremalen et al. “Aerosol and Surface Stability of SARS – cov – 2 as Compared with SARS – cov – 1.” N englj Med 2020 March DOI:10. 1056/nejmc2004973 (www.nejm.org/doi/full/10.1056/nejmc2004973).
  6. CDC: Interim Infection Prevention and Control Recommendations for Patients with Confirmed Coronavirus Disease 2019 (COVID – 19) or Persons Under Investigation for COVID – 19 in Healthcare Settings (www.cdc.gov/coronavirus/2019 – ncov/infection – control/control – re commendations.html).
  7. https://www.childrens.health.qld.gov.au/research/education/queensland – paediatric – emergency – care – education/optimus – bonus/
  8. Boast, A. And Munro, A., 2020. COVID – 19 And Children: What Do You Need To Know? . [online] Don`t Forget The Bubbles. Available at:
    <https://dontforgetthebubbles.com/covid – 19 – children – need – know/>[Accessed 16 March 2020].
  9. Jubran A. Pulse oximetry. Crit Care . 2015;19(1):272. Published 2015 Jul 16. Doi:10.1186/s13054 – 015 – 0984 – 8 10.Oskoui M, Levy G, Garland CJ, et al. The changing natural history of spinal muscular atrophy type 1. Neurology.2007;69(20):1931 – 1936 11. Personal opinion and literature search by Dr Sanjukta Dey