Five steering committees examine the literature

Airways Disorders
Defining and treating early COPD: Can we make a difference?

There is growing evidence that early COPD—before currently accepted spirometric or symptomatic criteria are present—may be an important clinical entity. The primary pathobiologic mechanisms in early COPD development include both abnormal lung development and accelerated lung aging (Augustí et al. Am J Respir Crit Care Med. 2018 Oct 15;198:8:978).

Martinez and colleagues recently proposed defining early COPD as age <50 with 10+ pack-year smoking history and at least one of the following: (1) early airflow limitation (postbronchodilator FEV1/FVC < lower limit of normal), (2) compatible CT scan abnormalities, (3) rapid decline in FEV1 (≥60 mL/yr) that is accelerated relative to FVC (Martinez et al. Am J Respir Crit Care Med. 2018 Jun 15;197[12]:1540).

A novel multiresolution CT scan imaging protocol described by Koo and coworkers found that substantial loss of small airways— specifically the terminal and transitional bronchioles—occurs in patients with mild-to-moderate COPD even prior to the development of emphysema on CT scan. These findings show that significant destruction of the small airways has occurred prior to the development of mild COPD (Koo et al. Lancet Respir Med. 2018 Aug;6:591).

Pharmacologic treatment for COPD is targeted at the reduction of symptoms and risk of exacerbation, as there remains no conclusive evidence that existing therapies modify long-term decline in lung function. It is unknown if pharmacotherapy for “early COPD” will alter the disease course. While not directly addressing this subset, information may be gleaned from trials on younger, more mild GOLD Stage 1 or Stage 2 patients. The Tie-COPD trial, the largest powered study to date of mild-to-moderate COPD, found that among patients with GOLD stage 1 or 2 COPD treatment with tiotropium compared with placebo for 2 years resulted in significantly higher FEV1 before bronchodilator use (between group difference of 157 mL) and slowed annual decline in FEV1 after bronchodilator use (Zhou et al. N Engl J Med. 2017 Sep 7;377[10]:923).

As our understanding of heterogeneity within COPD increases, striving for improved outcomes from our therapies—an impact on lung function in addition to symptom and exacerbation risk—may need to begin with the study of earlier treatment.

Megan Conroy, MD
Steering Committee Fellow-in-Training

Allen J. Blaivas, DO, FCCP
Steering Committee Vice-Chair

 

Clinical Pulmonary Medicine
Asthma-COPD overlap: An underappreciated phenotype of obstructive airway disease (OAD)

Asthma-COPD overlap (ACO) is a common yet underappreciated clinical entity within the complex OAD spectrum. Currently, there is no consensus criteria to define ACO; however, a roundtable consensus from an international group (Sin et al. Eur Respir J. 2016 Sep;48:664) suggests using major and minor criteria, with key features being airflow limitation, asthma history, and cigarette or biomass exposure. Several studies have shown that patients with ACO have severe disease, faster lung function decline, greater morbidity and mortality, and lower QoL (Alshabanat et al. PLoS One. 2015 Sep 3;10:e0136065).

There is paucity of data on the pathophysiology, risk factors, and clinical management given exclusion of these patients from clinical trials of asthma and COPD. Indeed, clinicians and researchers now realize that ACO is an umbrella term for multiple subphenotypes, including patients who have predominant asthma with some COPD features and others with predominant COPD with some asthma features. Overall, IgE level, FeNO, sputum, and blood eosinophils are usually higher in ACO than in COPD and relatively similar compared with asthma (Kobayashi et al. Int J Chron Obs Pulmon Dis. 2016 May 26;11:2117).

Most recently, a longitudinal study looked at predictors of ACO among NY firefighters exposed to WTC dust (Singh et al. CHEST. 2018 Dec;154[6]:1301). Pre-exposure low lung function and elevated blood eosinophils and IL4 (T2 inflammatory cytokine) increased risk of developing ACO among those exposed to WTC dust. Further research is required to better understand the interaction of environmental exposure and risk factors in the pathophysiology of ACO. It may be more pragmatic to use the unifying term OAD, as originally proposed in the Dutch hypothesis, and further delineate how several phenotypes of airway disease can be classified by combining traditional approaches with molecular and genomic analysis.

Munish Luthra, MD, FCCP
Steering Committee Member

Samantha D’Annunzio, MD
Steering Committee Member

 

 

Critical Care
Mechanical ventilation: One size fits all?

Mechanical ventilation (MV) is a lifesaving intervention in the ICU, but it has been associated with numerous complications ranging from overuse of sedation, atelectasis, and baro or volutrauma.

After 2000, it became well known that using a low tidal volume (VT) strategy (6 mL/kg predicted body weight, PBW) in patients with ARDS produced lower mortality and more ventilator-free days (N Engl J Med. 2000 May 4;342[18]:1301). In addition, a meta-analysis in 2012 demonstrated a lower relative risk of new lung injury, mortality, and pulmonary infections with low VT in non-ARDS patients (Serpa et al. JAMA. 2012 Oct 24/31;308[16]:1651). However, the included studies varied widely in their use of VT (9-12 mL/kg), duration of MV, and in mixed settings (ICU or operating room).

Recently, a large randomized clinical trial compared the effect of low (4-6 mL/kg, PBW) vs intermediate (8-10 mL/kg, PBW) VT ventilation strategy in non-ARDS ICU patients. Interestingly, the study concluded that there is no significant difference in ventilator-free days (21 days in each group), median length ICU and hospital stay, ICU mortality rates, and 28- and 90-day mortality. Also, there was no difference in new-onset ARDS, severe atelectasis, sedation use, and delirium (JAMA. 2018; 320[18]:1872). This study suggests that in non-ARDS patients, MV should be individualized according to each patient’s clinical situation, the nature of the disease, and its effect on lung mechanics, especially in patients who cannot tolerate low tidal volumes.

Margaret A. Disselkamp, MD
Steering Committee Member

Mohammed A. Megri, MD
Fellow-in-Training Steering Committee Member

 

Home-Based Mechanical Ventilation and Neuromuscular Disease
Improving access to sleep medicine care for patients with NMD

Sleep-disordered breathing (SDB) occurs in up to 5% of children, with adverse implications for growth and development. Children with neuromuscular disease are at significantly higher risk than unaffected children (Chiang et al. Children. 2018;5:e78). Respiratory dysfunction that may present as SDB before daytime impairment in gas exchange is evident. Diagnosing and treating SDB (to include OSA, CSA, and hypoventilation syndromes) early can significantly improve morbidity and mortality.

Unfortunately, diagnostic sleep medicine resources are limited. Children may wait up to a year or more for definitive testing with in-laboratory, attended polysomnography (PSG). Among children with neuromuscular disease, fewer than 10% may undergo a sleep clinic evaluation, and, of those that do, they may have only one visit over a 3-year period of care (Rose et al. Pediatr Pulmonol. 2018 Oct;53:1378). Home sleep testing (HST) has been evaluated as an alternative to PSG given lower cost, availability, and advantage of the child sleeping in his/her own bed. Although HST is indicated in adults with a high pretest probability for moderate to severe OSA, it is not indicated in children, given the potential to underestimate disease severity or to miss the diagnosis entirely (Kirk et al. J Clin Sleep Med. 2017 Oct 15;13[10]:1199). HST lacks electroencephalogram (EEG) and capnography. Technical recording mishaps are more common in children, but in-lab PSG has the advantage of on-site troubleshooting by a technologist.
A recently published study by Fishman and colleagues attempted to compare gold standard in-lab PSG to HST with capnography (Fishman et al. J Clin Sleep Med. 2018 Dec 15;14[12]:2013). Despite a well-designed study with a carefully selected population, HST failed to reliably diagnose SDB. HST underestimated disease severity and, in some cases, missed the diagnosis of SDB entirely. The addition of end tidal CO2 monitoring failed to improve diagnostic accuracy, and HST and PSG-ETco2 values were poorly correlated.

Although children with neuromuscular disease face long wait times for sleep evaluations, HST is clearly not the solution for now. It remains to be seen if innovations in HST with extended monitoring (and transcutaneous CO2) become viable. In the meantime, finding ways to improve access to sleep medicine care for children with neuromuscular disease is a must.

Jacob Collen, MD, FCCP
Steering Committee Member

 

Interstitial and Diffuse Lung Disease
Idiopathic pneumonias that are not all that idiopathic

Despite being defined as an individual entity for research purposes in 2015 (Fisher et al. Eur Respir J. 2015;46:976), interstitial pneumonias with autoimmune features (IPAF) remain a heterogeneous group of interstitial lung diseases that puzzle the clinician. Since the introduction of the IPAF definition, there have been attempts to validate the diagnostic criteria and study their prognostic implications. Some of these studies showed differential prognosis in patients who met the IPAF criteria (Oldham et al. Eur Respir J. 2016;47:1767).

Although the implications of the presence of autoimmune antibodies in idiopathic interstitial pneumonias (IIPs) is not fully understood, the treatment often entails immunosuppression, especially in those with non-UIP patterns of disease and/or clinical features of autoimmune disease. The stakes are high when IIPs are associated with antibodies correlated with rapidly progressive disease, such as MDA-5 antibody or antisynthetase antibodies. Pulmonologists often lack the clinical expertise to detect occult autoimmune disorders, though the role of the rheumatologist in facilitating the diagnosis and treatment of IPAF is not well delineated. Most health-care systems are not equipped with collaborative ILD-rheumatology clinics or even easy access to a rheumatologist. There is a need for real-world pragmatic studies to establish the optimal way to evaluate patients with ILD for autoimmune features and identify patients who would benefit most from an early referral to rheumatology to aid with diagnosis, treatment, and sometimes monitoring for extrapulmonary manifestations of autoimmune disorders.

Avanthika Thanushi Wynn, MD
Steering Committee Fellow-in-Training

Airways Disorders
Defining and treating early COPD: Can we make a difference?

There is growing evidence that early COPD—before currently accepted spirometric or symptomatic criteria are present—may be an important clinical entity. The primary pathobiologic mechanisms in early COPD development include both abnormal lung development and accelerated lung aging (Augustí et al. Am J Respir Crit Care Med. 2018 Oct 15;198:8:978).

Martinez and colleagues recently proposed defining early COPD as age <50 with 10+ pack-year smoking history and at least one of the following: (1) early airflow limitation (postbronchodilator FEV1/FVC < lower limit of normal), (2) compatible CT scan abnormalities, (3) rapid decline in FEV1 (≥60 mL/yr) that is accelerated relative to FVC (Martinez et al. Am J Respir Crit Care Med. 2018 Jun 15;197[12]:1540).

A novel multiresolution CT scan imaging protocol described by Koo and coworkers found that substantial loss of small airways— specifically the terminal and transitional bronchioles—occurs in patients with mild-to-moderate COPD even prior to the development of emphysema on CT scan. These findings show that significant destruction of the small airways has occurred prior to the development of mild COPD (Koo et al. Lancet Respir Med. 2018 Aug;6:591).

Pharmacologic treatment for COPD is targeted at the reduction of symptoms and risk of exacerbation, as there remains no conclusive evidence that existing therapies modify long-term decline in lung function. It is unknown if pharmacotherapy for “early COPD” will alter the disease course. While not directly addressing this subset, information may be gleaned from trials on younger, more mild GOLD Stage 1 or Stage 2 patients. The Tie-COPD trial, the largest powered study to date of mild-to-moderate COPD, found that among patients with GOLD stage 1 or 2 COPD treatment with tiotropium compared with placebo for 2 years resulted in significantly higher FEV1 before bronchodilator use (between group difference of 157 mL) and slowed annual decline in FEV1 after bronchodilator use (Zhou et al. N Engl J Med. 2017 Sep 7;377[10]:923).

As our understanding of heterogeneity within COPD increases, striving for improved outcomes from our therapies—an impact on lung function in addition to symptom and exacerbation risk—may need to begin with the study of earlier treatment.

Megan Conroy, MD
Steering Committee Fellow-in-Training

Allen J. Blaivas, DO, FCCP
Steering Committee Vice-Chair

 

Clinical Pulmonary Medicine
Asthma-COPD overlap: An underappreciated phenotype of obstructive airway disease (OAD)

Asthma-COPD overlap (ACO) is a common yet underappreciated clinical entity within the complex OAD spectrum. Currently, there is no consensus criteria to define ACO; however, a roundtable consensus from an international group (Sin et al. Eur Respir J. 2016 Sep;48:664) suggests using major and minor criteria, with key features being airflow limitation, asthma history, and cigarette or biomass exposure. Several studies have shown that patients with ACO have severe disease, faster lung function decline, greater morbidity and mortality, and lower QoL (Alshabanat et al. PLoS One. 2015 Sep 3;10:e0136065).

There is paucity of data on the pathophysiology, risk factors, and clinical management given exclusion of these patients from clinical trials of asthma and COPD. Indeed, clinicians and researchers now realize that ACO is an umbrella term for multiple subphenotypes, including patients who have predominant asthma with some COPD features and others with predominant COPD with some asthma features. Overall, IgE level, FeNO, sputum, and blood eosinophils are usually higher in ACO than in COPD and relatively similar compared with asthma (Kobayashi et al. Int J Chron Obs Pulmon Dis. 2016 May 26;11:2117).

Most recently, a longitudinal study looked at predictors of ACO among NY firefighters exposed to WTC dust (Singh et al. CHEST. 2018 Dec;154[6]:1301). Pre-exposure low lung function and elevated blood eosinophils and IL4 (T2 inflammatory cytokine) increased risk of developing ACO among those exposed to WTC dust. Further research is required to better understand the interaction of environmental exposure and risk factors in the pathophysiology of ACO. It may be more pragmatic to use the unifying term OAD, as originally proposed in the Dutch hypothesis, and further delineate how several phenotypes of airway disease can be classified by combining traditional approaches with molecular and genomic analysis.

Munish Luthra, MD, FCCP
Steering Committee Member

Samantha D’Annunzio, MD
Steering Committee Member

 

 

Critical Care
Mechanical ventilation: One size fits all?

Mechanical ventilation (MV) is a lifesaving intervention in the ICU, but it has been associated with numerous complications ranging from overuse of sedation, atelectasis, and baro or volutrauma.

After 2000, it became well known that using a low tidal volume (VT) strategy (6 mL/kg predicted body weight, PBW) in patients with ARDS produced lower mortality and more ventilator-free days (N Engl J Med. 2000 May 4;342[18]:1301). In addition, a meta-analysis in 2012 demonstrated a lower relative risk of new lung injury, mortality, and pulmonary infections with low VT in non-ARDS patients (Serpa et al. JAMA. 2012 Oct 24/31;308[16]:1651). However, the included studies varied widely in their use of VT (9-12 mL/kg), duration of MV, and in mixed settings (ICU or operating room).

Recently, a large randomized clinical trial compared the effect of low (4-6 mL/kg, PBW) vs intermediate (8-10 mL/kg, PBW) VT ventilation strategy in non-ARDS ICU patients. Interestingly, the study concluded that there is no significant difference in ventilator-free days (21 days in each group), median length ICU and hospital stay, ICU mortality rates, and 28- and 90-day mortality. Also, there was no difference in new-onset ARDS, severe atelectasis, sedation use, and delirium (JAMA. 2018; 320[18]:1872). This study suggests that in non-ARDS patients, MV should be individualized according to each patient’s clinical situation, the nature of the disease, and its effect on lung mechanics, especially in patients who cannot tolerate low tidal volumes.

Margaret A. Disselkamp, MD
Steering Committee Member

Mohammed A. Megri, MD
Fellow-in-Training Steering Committee Member

 

Home-Based Mechanical Ventilation and Neuromuscular Disease
Improving access to sleep medicine care for patients with NMD

Sleep-disordered breathing (SDB) occurs in up to 5% of children, with adverse implications for growth and development. Children with neuromuscular disease are at significantly higher risk than unaffected children (Chiang et al. Children. 2018;5:e78). Respiratory dysfunction that may present as SDB before daytime impairment in gas exchange is evident. Diagnosing and treating SDB (to include OSA, CSA, and hypoventilation syndromes) early can significantly improve morbidity and mortality.

Unfortunately, diagnostic sleep medicine resources are limited. Children may wait up to a year or more for definitive testing with in-laboratory, attended polysomnography (PSG). Among children with neuromuscular disease, fewer than 10% may undergo a sleep clinic evaluation, and, of those that do, they may have only one visit over a 3-year period of care (Rose et al. Pediatr Pulmonol. 2018 Oct;53:1378). Home sleep testing (HST) has been evaluated as an alternative to PSG given lower cost, availability, and advantage of the child sleeping in his/her own bed. Although HST is indicated in adults with a high pretest probability for moderate to severe OSA, it is not indicated in children, given the potential to underestimate disease severity or to miss the diagnosis entirely (Kirk et al. J Clin Sleep Med. 2017 Oct 15;13[10]:1199). HST lacks electroencephalogram (EEG) and capnography. Technical recording mishaps are more common in children, but in-lab PSG has the advantage of on-site troubleshooting by a technologist.
A recently published study by Fishman and colleagues attempted to compare gold standard in-lab PSG to HST with capnography (Fishman et al. J Clin Sleep Med. 2018 Dec 15;14[12]:2013). Despite a well-designed study with a carefully selected population, HST failed to reliably diagnose SDB. HST underestimated disease severity and, in some cases, missed the diagnosis of SDB entirely. The addition of end tidal CO2 monitoring failed to improve diagnostic accuracy, and HST and PSG-ETco2 values were poorly correlated.

Although children with neuromuscular disease face long wait times for sleep evaluations, HST is clearly not the solution for now. It remains to be seen if innovations in HST with extended monitoring (and transcutaneous CO2) become viable. In the meantime, finding ways to improve access to sleep medicine care for children with neuromuscular disease is a must.

Jacob Collen, MD, FCCP
Steering Committee Member

 

Interstitial and Diffuse Lung Disease
Idiopathic pneumonias that are not all that idiopathic

Despite being defined as an individual entity for research purposes in 2015 (Fisher et al. Eur Respir J. 2015;46:976), interstitial pneumonias with autoimmune features (IPAF) remain a heterogeneous group of interstitial lung diseases that puzzle the clinician. Since the introduction of the IPAF definition, there have been attempts to validate the diagnostic criteria and study their prognostic implications. Some of these studies showed differential prognosis in patients who met the IPAF criteria (Oldham et al. Eur Respir J. 2016;47:1767).

Although the implications of the presence of autoimmune antibodies in idiopathic interstitial pneumonias (IIPs) is not fully understood, the treatment often entails immunosuppression, especially in those with non-UIP patterns of disease and/or clinical features of autoimmune disease. The stakes are high when IIPs are associated with antibodies correlated with rapidly progressive disease, such as MDA-5 antibody or antisynthetase antibodies. Pulmonologists often lack the clinical expertise to detect occult autoimmune disorders, though the role of the rheumatologist in facilitating the diagnosis and treatment of IPAF is not well delineated. Most health-care systems are not equipped with collaborative ILD-rheumatology clinics or even easy access to a rheumatologist. There is a need for real-world pragmatic studies to establish the optimal way to evaluate patients with ILD for autoimmune features and identify patients who would benefit most from an early referral to rheumatology to aid with diagnosis, treatment, and sometimes monitoring for extrapulmonary manifestations of autoimmune disorders.

Avanthika Thanushi Wynn, MD
Steering Committee Fellow-in-Training

Airways Disorders
Defining and treating early COPD: Can we make a difference?

There is growing evidence that early COPD—before currently accepted spirometric or symptomatic criteria are present—may be an important clinical entity. The primary pathobiologic mechanisms in early COPD development include both abnormal lung development and accelerated lung aging (Augustí et al. Am J Respir Crit Care Med. 2018 Oct 15;198:8:978).

Martinez and colleagues recently proposed defining early COPD as age <50 with 10+ pack-year smoking history and at least one of the following: (1) early airflow limitation (postbronchodilator FEV1/FVC < lower limit of normal), (2) compatible CT scan abnormalities, (3) rapid decline in FEV1 (≥60 mL/yr) that is accelerated relative to FVC (Martinez et al. Am J Respir Crit Care Med. 2018 Jun 15;197[12]:1540).

A novel multiresolution CT scan imaging protocol described by Koo and coworkers found that substantial loss of small airways— specifically the terminal and transitional bronchioles—occurs in patients with mild-to-moderate COPD even prior to the development of emphysema on CT scan. These findings show that significant destruction of the small airways has occurred prior to the development of mild COPD (Koo et al. Lancet Respir Med. 2018 Aug;6:591).

Pharmacologic treatment for COPD is targeted at the reduction of symptoms and risk of exacerbation, as there remains no conclusive evidence that existing therapies modify long-term decline in lung function. It is unknown if pharmacotherapy for “early COPD” will alter the disease course. While not directly addressing this subset, information may be gleaned from trials on younger, more mild GOLD Stage 1 or Stage 2 patients. The Tie-COPD trial, the largest powered study to date of mild-to-moderate COPD, found that among patients with GOLD stage 1 or 2 COPD treatment with tiotropium compared with placebo for 2 years resulted in significantly higher FEV1 before bronchodilator use (between group difference of 157 mL) and slowed annual decline in FEV1 after bronchodilator use (Zhou et al. N Engl J Med. 2017 Sep 7;377[10]:923).

As our understanding of heterogeneity within COPD increases, striving for improved outcomes from our therapies—an impact on lung function in addition to symptom and exacerbation risk—may need to begin with the study of earlier treatment.

Megan Conroy, MD
Steering Committee Fellow-in-Training

Allen J. Blaivas, DO, FCCP
Steering Committee Vice-Chair

 

Clinical Pulmonary Medicine
Asthma-COPD overlap: An underappreciated phenotype of obstructive airway disease (OAD)

Asthma-COPD overlap (ACO) is a common yet underappreciated clinical entity within the complex OAD spectrum. Currently, there is no consensus criteria to define ACO; however, a roundtable consensus from an international group (Sin et al. Eur Respir J. 2016 Sep;48:664) suggests using major and minor criteria, with key features being airflow limitation, asthma history, and cigarette or biomass exposure. Several studies have shown that patients with ACO have severe disease, faster lung function decline, greater morbidity and mortality, and lower QoL (Alshabanat et al. PLoS One. 2015 Sep 3;10:e0136065).

There is paucity of data on the pathophysiology, risk factors, and clinical management given exclusion of these patients from clinical trials of asthma and COPD. Indeed, clinicians and researchers now realize that ACO is an umbrella term for multiple subphenotypes, including patients who have predominant asthma with some COPD features and others with predominant COPD with some asthma features. Overall, IgE level, FeNO, sputum, and blood eosinophils are usually higher in ACO than in COPD and relatively similar compared with asthma (Kobayashi et al. Int J Chron Obs Pulmon Dis. 2016 May 26;11:2117).

Most recently, a longitudinal study looked at predictors of ACO among NY firefighters exposed to WTC dust (Singh et al. CHEST. 2018 Dec;154[6]:1301). Pre-exposure low lung function and elevated blood eosinophils and IL4 (T2 inflammatory cytokine) increased risk of developing ACO among those exposed to WTC dust. Further research is required to better understand the interaction of environmental exposure and risk factors in the pathophysiology of ACO. It may be more pragmatic to use the unifying term OAD, as originally proposed in the Dutch hypothesis, and further delineate how several phenotypes of airway disease can be classified by combining traditional approaches with molecular and genomic analysis.

Munish Luthra, MD, FCCP
Steering Committee Member

Samantha D’Annunzio, MD
Steering Committee Member

 

 

Critical Care
Mechanical ventilation: One size fits all?

Mechanical ventilation (MV) is a lifesaving intervention in the ICU, but it has been associated with numerous complications ranging from overuse of sedation, atelectasis, and baro or volutrauma.

After 2000, it became well known that using a low tidal volume (VT) strategy (6 mL/kg predicted body weight, PBW) in patients with ARDS produced lower mortality and more ventilator-free days (N Engl J Med. 2000 May 4;342[18]:1301). In addition, a meta-analysis in 2012 demonstrated a lower relative risk of new lung injury, mortality, and pulmonary infections with low VT in non-ARDS patients (Serpa et al. JAMA. 2012 Oct 24/31;308[16]:1651). However, the included studies varied widely in their use of VT (9-12 mL/kg), duration of MV, and in mixed settings (ICU or operating room).

Recently, a large randomized clinical trial compared the effect of low (4-6 mL/kg, PBW) vs intermediate (8-10 mL/kg, PBW) VT ventilation strategy in non-ARDS ICU patients. Interestingly, the study concluded that there is no significant difference in ventilator-free days (21 days in each group), median length ICU and hospital stay, ICU mortality rates, and 28- and 90-day mortality. Also, there was no difference in new-onset ARDS, severe atelectasis, sedation use, and delirium (JAMA. 2018; 320[18]:1872). This study suggests that in non-ARDS patients, MV should be individualized according to each patient’s clinical situation, the nature of the disease, and its effect on lung mechanics, especially in patients who cannot tolerate low tidal volumes.

Margaret A. Disselkamp, MD
Steering Committee Member

Mohammed A. Megri, MD
Fellow-in-Training Steering Committee Member

 

Home-Based Mechanical Ventilation and Neuromuscular Disease
Improving access to sleep medicine care for patients with NMD

Sleep-disordered breathing (SDB) occurs in up to 5% of children, with adverse implications for growth and development. Children with neuromuscular disease are at significantly higher risk than unaffected children (Chiang et al. Children. 2018;5:e78). Respiratory dysfunction that may present as SDB before daytime impairment in gas exchange is evident. Diagnosing and treating SDB (to include OSA, CSA, and hypoventilation syndromes) early can significantly improve morbidity and mortality.

Unfortunately, diagnostic sleep medicine resources are limited. Children may wait up to a year or more for definitive testing with in-laboratory, attended polysomnography (PSG). Among children with neuromuscular disease, fewer than 10% may undergo a sleep clinic evaluation, and, of those that do, they may have only one visit over a 3-year period of care (Rose et al. Pediatr Pulmonol. 2018 Oct;53:1378). Home sleep testing (HST) has been evaluated as an alternative to PSG given lower cost, availability, and advantage of the child sleeping in his/her own bed. Although HST is indicated in adults with a high pretest probability for moderate to severe OSA, it is not indicated in children, given the potential to underestimate disease severity or to miss the diagnosis entirely (Kirk et al. J Clin Sleep Med. 2017 Oct 15;13[10]:1199). HST lacks electroencephalogram (EEG) and capnography. Technical recording mishaps are more common in children, but in-lab PSG has the advantage of on-site troubleshooting by a technologist.
A recently published study by Fishman and colleagues attempted to compare gold standard in-lab PSG to HST with capnography (Fishman et al. J Clin Sleep Med. 2018 Dec 15;14[12]:2013). Despite a well-designed study with a carefully selected population, HST failed to reliably diagnose SDB. HST underestimated disease severity and, in some cases, missed the diagnosis of SDB entirely. The addition of end tidal CO2 monitoring failed to improve diagnostic accuracy, and HST and PSG-ETco2 values were poorly correlated.

Although children with neuromuscular disease face long wait times for sleep evaluations, HST is clearly not the solution for now. It remains to be seen if innovations in HST with extended monitoring (and transcutaneous CO2) become viable. In the meantime, finding ways to improve access to sleep medicine care for children with neuromuscular disease is a must.

Jacob Collen, MD, FCCP
Steering Committee Member

 

Interstitial and Diffuse Lung Disease
Idiopathic pneumonias that are not all that idiopathic

Despite being defined as an individual entity for research purposes in 2015 (Fisher et al. Eur Respir J. 2015;46:976), interstitial pneumonias with autoimmune features (IPAF) remain a heterogeneous group of interstitial lung diseases that puzzle the clinician. Since the introduction of the IPAF definition, there have been attempts to validate the diagnostic criteria and study their prognostic implications. Some of these studies showed differential prognosis in patients who met the IPAF criteria (Oldham et al. Eur Respir J. 2016;47:1767).

Although the implications of the presence of autoimmune antibodies in idiopathic interstitial pneumonias (IIPs) is not fully understood, the treatment often entails immunosuppression, especially in those with non-UIP patterns of disease and/or clinical features of autoimmune disease. The stakes are high when IIPs are associated with antibodies correlated with rapidly progressive disease, such as MDA-5 antibody or antisynthetase antibodies. Pulmonologists often lack the clinical expertise to detect occult autoimmune disorders, though the role of the rheumatologist in facilitating the diagnosis and treatment of IPAF is not well delineated. Most health-care systems are not equipped with collaborative ILD-rheumatology clinics or even easy access to a rheumatologist. There is a need for real-world pragmatic studies to establish the optimal way to evaluate patients with ILD for autoimmune features and identify patients who would benefit most from an early referral to rheumatology to aid with diagnosis, treatment, and sometimes monitoring for extrapulmonary manifestations of autoimmune disorders.

Avanthika Thanushi Wynn, MD
Steering Committee Fellow-in-Training