- Email: [email protected]
Choice of Imaging Studies in Acutely Ill Pregnant Women
AUTHOR CONTRIBUTIONS: F. G., N. M., and M .L. V. researched data, contributed to discussions, wrote the manuscript, and reviewed/edited the manuscript. A. B. T., A. P., B. R., C. A., L. L. V., M. P. H., T. P., W. T., and X. L. N. researched data, contributed to discussions, and reviewed/edited the manuscript. FINANCIAL/NONFINANCIAL DISCLOSURES:
None declared.
*WRITING COMMITTEE MEMBERS FOR [The Institut de Recherche en Santé Respiratoire des Pays de la Loire Sleep Cohort Group]: Centre Hospitalier Universitaire, Angers, France: Christine Person, Pascaline Priou; Centre Hospitalier, Le Mans, France: François Goupil, Olivier Molinier; Centre Hospitalier, La Roche sur Yon, France: Philippe Breton, Kamel Berkani; Pôle santé des Olonnes, Olonne sur Mer, France: Marie Langelot-Richard; Centre Hospitalier Universitaire, Nantes, France: Sylvaine Chollet, Sandrine Jaffre, Frédéric Corne; Nouvelles Cliniques Nantaises, Nantes, France: Marie-Pierre Humeau, Marc Normand de la Tranchade; ALTADIR, Beaucouzé, France: Jean-Louis Racineux, Christelle Gosselin; CERMES, CNRS UMR8211 - INSERM U988 EHESS, site CNRS, Villejuif, France: Nathalie Pelletier-Fleury. CORRESPONDENCE TO: Frédéric Gagnadoux, MD, PhD, Département de Pneumologie, Université d’Angers, CHU Angers, 4 rue Larrey, 49033 Angers Cedex, France; e-mail: frgagnadoux@ chu-angers.fr ADDITIONAL INFORMATION: The e-Appendix, e-Figures, and e-Tables can be found in the Supplemental Materials section of the online article. Copyright Ó 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved. DOI: http://dx.doi.org/10.1016/j.chest.2015.09.032
References 1. Ye L, Pien GW, Ratcliffe SJ, et al. The different clinical faces of obstructive sleep apnoea: a cluster analysis. Eur Respir J. 2014;44(6): 1600-1607. 2. Sipsma HL, Falb KL, Willie T, et al. Violence against Congolese refugee women in Rwanda and mental health: a cross-sectional study using latent class analysis. BMJ Open. 2015;5(4):e006299. 3. Sawyer AM, Gooneratne NS, Marcus CL, Ofer D, Richards KC, Weaver TE. A systematic review of CPAP adherence across age groups: clinical and empiric insights for developing CPAP adherence interventions. Sleep Med Rev. 2011;15(6):343-356. 4. Crawford MR, Espie CA, Bartlett DJ, Grunstein RR. Integrating psychology and medicine in CPAP adherence—new concepts? Sleep Med Rev. 2013;18(2):123-139. 5. Gagnadoux F, Le Vaillant M, Goupil F, et al. Influence of marital status and employment status on long-term adherence with continuous positive airway pressure in sleep apnea patients. PLoS One. 2011;6(8):e22503.
Choice of Imaging Studies in Acutely Ill Pregnant Women To the Editor:
The case report in CHEST (June 2015) by Daglian and Patrawalla1 highlights the challenge of emergency care of the obstetric patient. While the innovative use of lung ultrasonography for rapid and accurate diagnosis in respiratory failure is promising and could be particularly beneficial to the pregnant patient, we would like to suggest redirecting strategies for selecting diagnostic studies in complicated pregnant patients to focus on
290 Correspondence
timely diagnosis and avoiding undue concerns about safety risk. As in the nonpregnant population, lung ultrasonography would be most attractive if it has good positive and negative predictive value, is safe, and there is expertise with using and interpreting it locally. It is common for providers to withhold tests in a pregnant patient due to presumed risks to the fetus. This may lead to delays in diagnosis as well as diagnostic and therapeutic errors, resulting in similar or worse harm. In this case report, chest radiograph was initially withheld, and pulmonary embolism (PE) was excluded based on Doppler testing of the legs alone. Though PE was unlikely in this patient, clinicians had a high enough suspicion to empirically initiate anticoagulation treatment, bypassing diagnostic testing. Such practices are considered substandard care in the nonpregnant population; the same should apply to pregnancy. In the United States, reducing maternal mortality and morbidity remains a challenge, with the maternal mortality ratio doubling between 1990 and 20132 in part due to inconsistent obstetric practice across hospitals.2 Peripartum VTE, still one of the leading causes of maternal deaths in the United States, has been identified as one of the priority bundles by the National Partnership for Maternal Safety.3 By standardizing care through the use of evidence-based national guidelines, we can decrease PE-related maternal deaths as seen in the United Kingdom.4 Current guidelines recommend that in pregnant women with suspected PE and no signs and symptoms of DVT (as in this case), studies of the pulmonary vasculature should not be delayed.5,6 This includes chest radiograph followed by either a CT angiogram or a ventilation perfusion scan. While the risk of teratogenicity requires a radiation threshold of at least 5 rad,7 a CT angiogram or chest radiograph exposes the fetus to very small amounts of radiation (0.01 rad and 0.0002 rad, respectively).7 Lung ultrasonography may prove to be a valuable tool, however, it should not replace our current standard of care in pregnant women until it becomes fully validated both in and outside of pregnancy. Tabassum Firoz, MD Vancouver, BC, Canada Margaret A. Miller, MD Ghada Bourjeily, MD Providence, RI
[
149#1 CHEST JANUARY 2016
]
AFFILIATIONS: From the Division of General Internal Medicine (Dr Firoz), The University of British Columbia; and Department of Medicine, Alpert Medical School (Drs Miller and Bourjeily), Brown University. FINANCIAL/NONFINANCIAL DISCLOSURES: None declared. CORRESPONDENCE TO: Ghada Bourjeily, MD, 146 W River St, Ste 11C, Providence, RI 02904; e-mail: [email protected] Copyright Ó 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved. DOI: http://dx.doi.org/10.1016/j.chest.2015.10.055
References 1. Daglian DM, Patrawalla P. Pregnant patient with progressive hypoxemic respiratory failure. Chest. 2015;147(6):e205-e207. 2. Agrawal P. Maternal mortality and morbidity in the United States of America. Bull World Health Organ. 2015;93(3):135. 3. D’Alton ME, Main EK, Menard MK, Levy BS. The National Partnership for Maternal Safety. Obstet Gynecol. 2014;123(5):973-977. 4. Lewis G. Saving Mothers’ Lives: the continuing benefits for maternal health from the United Kingdom (UK) Confidential Enquires into Maternal Deaths. Semin Perinatol. 2012;36(1):19-26. 5. Pulmonary Embolism in Pregnancy. Diagnosis and Treatment (7th Draft 4-5-2013). American College of Obstetricians and Gynecologists website. http://www.acog.org/w/media/Districts/ District VIII/PulmonaryEmbolismPregnancy.pdf?dmc¼1. Accessed July 1, 2015. 6. Leung AN, Bull TM, Jaeschke R, et al; ATS/STR Committee on Pulmonary Embolism in Pregnancy. An official American Thoracic Society/Society of Thoracic Radiology clinical practice guideline: evaluation of suspected pulmonary embolism in pregnancy. Am J Respir Crit Care Med. 2011;184(10):1200-1208. 7. ACOG Committee on Obstetric Practice. ACOG Committee Opinion. Number 299, September 2004 (replaces No. 158, September 1995). Guidelines for diagnostic imaging during pregnancy. Obstet Gynecol. 2004;104(3):647-651.
Lung Density in Extremely Large Healthy Lungs To the Editor:
One of the possible limitations of the study presented by Brown et al1 recently in CHEST (October 2015) is that the analyzed larger lungs were of subjects with COPD, where alveolar size and density may have been influenced by disease. In this regard, competition free divers who practice glossopharyngeal breathing are a peculiar group to study because they are known to be able to greatly expand their maximal lung volumes but retain their normal baseline lung compliance at functional residual capacity.2,3 In collaboration, we constructed a chart of the data from Brown et al1 together with lung size and alveolar density calculations from CT scans previously performed on six competitive free divers3,4 (Fig 1). The range for nonpathologic lung volumes at maximum inspiration is now from approximately 3,000 to 12,000 mL, substantially extending the previously presented curvilinear relationship. These new data extend the range for normal lungs to completely surround the data for the subjects with COPD. These extended data support the notion that people with larger lungs have bigger alveoli and that this anatomic
–500
HU mean
–600
–700
–800
–900
–1,000
0
1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 11,000 total lung air volume (mL)
Figure 1 – Brown et al1 mean lung density (HU) and lung volume continuum. Blue circles ¼ subjects with COPD; gray circles ¼ subjects without COPD; and red circles ¼ additional free diving subjects. HU ¼ Hounsfield unit.
journal.publications.chestnet.org
291
None declared.
*WRITING COMMITTEE MEMBERS FOR [The Institut de Recherche en Santé Respiratoire des Pays de la Loire Sleep Cohort Group]: Centre Hospitalier Universitaire, Angers, France: Christine Person, Pascaline Priou; Centre Hospitalier, Le Mans, France: François Goupil, Olivier Molinier; Centre Hospitalier, La Roche sur Yon, France: Philippe Breton, Kamel Berkani; Pôle santé des Olonnes, Olonne sur Mer, France: Marie Langelot-Richard; Centre Hospitalier Universitaire, Nantes, France: Sylvaine Chollet, Sandrine Jaffre, Frédéric Corne; Nouvelles Cliniques Nantaises, Nantes, France: Marie-Pierre Humeau, Marc Normand de la Tranchade; ALTADIR, Beaucouzé, France: Jean-Louis Racineux, Christelle Gosselin; CERMES, CNRS UMR8211 - INSERM U988 EHESS, site CNRS, Villejuif, France: Nathalie Pelletier-Fleury. CORRESPONDENCE TO: Frédéric Gagnadoux, MD, PhD, Département de Pneumologie, Université d’Angers, CHU Angers, 4 rue Larrey, 49033 Angers Cedex, France; e-mail: frgagnadoux@ chu-angers.fr ADDITIONAL INFORMATION: The e-Appendix, e-Figures, and e-Tables can be found in the Supplemental Materials section of the online article. Copyright Ó 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved. DOI: http://dx.doi.org/10.1016/j.chest.2015.09.032
References 1. Ye L, Pien GW, Ratcliffe SJ, et al. The different clinical faces of obstructive sleep apnoea: a cluster analysis. Eur Respir J. 2014;44(6): 1600-1607. 2. Sipsma HL, Falb KL, Willie T, et al. Violence against Congolese refugee women in Rwanda and mental health: a cross-sectional study using latent class analysis. BMJ Open. 2015;5(4):e006299. 3. Sawyer AM, Gooneratne NS, Marcus CL, Ofer D, Richards KC, Weaver TE. A systematic review of CPAP adherence across age groups: clinical and empiric insights for developing CPAP adherence interventions. Sleep Med Rev. 2011;15(6):343-356. 4. Crawford MR, Espie CA, Bartlett DJ, Grunstein RR. Integrating psychology and medicine in CPAP adherence—new concepts? Sleep Med Rev. 2013;18(2):123-139. 5. Gagnadoux F, Le Vaillant M, Goupil F, et al. Influence of marital status and employment status on long-term adherence with continuous positive airway pressure in sleep apnea patients. PLoS One. 2011;6(8):e22503.
Choice of Imaging Studies in Acutely Ill Pregnant Women To the Editor:
The case report in CHEST (June 2015) by Daglian and Patrawalla1 highlights the challenge of emergency care of the obstetric patient. While the innovative use of lung ultrasonography for rapid and accurate diagnosis in respiratory failure is promising and could be particularly beneficial to the pregnant patient, we would like to suggest redirecting strategies for selecting diagnostic studies in complicated pregnant patients to focus on
290 Correspondence
timely diagnosis and avoiding undue concerns about safety risk. As in the nonpregnant population, lung ultrasonography would be most attractive if it has good positive and negative predictive value, is safe, and there is expertise with using and interpreting it locally. It is common for providers to withhold tests in a pregnant patient due to presumed risks to the fetus. This may lead to delays in diagnosis as well as diagnostic and therapeutic errors, resulting in similar or worse harm. In this case report, chest radiograph was initially withheld, and pulmonary embolism (PE) was excluded based on Doppler testing of the legs alone. Though PE was unlikely in this patient, clinicians had a high enough suspicion to empirically initiate anticoagulation treatment, bypassing diagnostic testing. Such practices are considered substandard care in the nonpregnant population; the same should apply to pregnancy. In the United States, reducing maternal mortality and morbidity remains a challenge, with the maternal mortality ratio doubling between 1990 and 20132 in part due to inconsistent obstetric practice across hospitals.2 Peripartum VTE, still one of the leading causes of maternal deaths in the United States, has been identified as one of the priority bundles by the National Partnership for Maternal Safety.3 By standardizing care through the use of evidence-based national guidelines, we can decrease PE-related maternal deaths as seen in the United Kingdom.4 Current guidelines recommend that in pregnant women with suspected PE and no signs and symptoms of DVT (as in this case), studies of the pulmonary vasculature should not be delayed.5,6 This includes chest radiograph followed by either a CT angiogram or a ventilation perfusion scan. While the risk of teratogenicity requires a radiation threshold of at least 5 rad,7 a CT angiogram or chest radiograph exposes the fetus to very small amounts of radiation (0.01 rad and 0.0002 rad, respectively).7 Lung ultrasonography may prove to be a valuable tool, however, it should not replace our current standard of care in pregnant women until it becomes fully validated both in and outside of pregnancy. Tabassum Firoz, MD Vancouver, BC, Canada Margaret A. Miller, MD Ghada Bourjeily, MD Providence, RI
[
149#1 CHEST JANUARY 2016
]
AFFILIATIONS: From the Division of General Internal Medicine (Dr Firoz), The University of British Columbia; and Department of Medicine, Alpert Medical School (Drs Miller and Bourjeily), Brown University. FINANCIAL/NONFINANCIAL DISCLOSURES: None declared. CORRESPONDENCE TO: Ghada Bourjeily, MD, 146 W River St, Ste 11C, Providence, RI 02904; e-mail: [email protected] Copyright Ó 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved. DOI: http://dx.doi.org/10.1016/j.chest.2015.10.055
References 1. Daglian DM, Patrawalla P. Pregnant patient with progressive hypoxemic respiratory failure. Chest. 2015;147(6):e205-e207. 2. Agrawal P. Maternal mortality and morbidity in the United States of America. Bull World Health Organ. 2015;93(3):135. 3. D’Alton ME, Main EK, Menard MK, Levy BS. The National Partnership for Maternal Safety. Obstet Gynecol. 2014;123(5):973-977. 4. Lewis G. Saving Mothers’ Lives: the continuing benefits for maternal health from the United Kingdom (UK) Confidential Enquires into Maternal Deaths. Semin Perinatol. 2012;36(1):19-26. 5. Pulmonary Embolism in Pregnancy. Diagnosis and Treatment (7th Draft 4-5-2013). American College of Obstetricians and Gynecologists website. http://www.acog.org/w/media/Districts/ District VIII/PulmonaryEmbolismPregnancy.pdf?dmc¼1. Accessed July 1, 2015. 6. Leung AN, Bull TM, Jaeschke R, et al; ATS/STR Committee on Pulmonary Embolism in Pregnancy. An official American Thoracic Society/Society of Thoracic Radiology clinical practice guideline: evaluation of suspected pulmonary embolism in pregnancy. Am J Respir Crit Care Med. 2011;184(10):1200-1208. 7. ACOG Committee on Obstetric Practice. ACOG Committee Opinion. Number 299, September 2004 (replaces No. 158, September 1995). Guidelines for diagnostic imaging during pregnancy. Obstet Gynecol. 2004;104(3):647-651.
Lung Density in Extremely Large Healthy Lungs To the Editor:
One of the possible limitations of the study presented by Brown et al1 recently in CHEST (October 2015) is that the analyzed larger lungs were of subjects with COPD, where alveolar size and density may have been influenced by disease. In this regard, competition free divers who practice glossopharyngeal breathing are a peculiar group to study because they are known to be able to greatly expand their maximal lung volumes but retain their normal baseline lung compliance at functional residual capacity.2,3 In collaboration, we constructed a chart of the data from Brown et al1 together with lung size and alveolar density calculations from CT scans previously performed on six competitive free divers3,4 (Fig 1). The range for nonpathologic lung volumes at maximum inspiration is now from approximately 3,000 to 12,000 mL, substantially extending the previously presented curvilinear relationship. These new data extend the range for normal lungs to completely surround the data for the subjects with COPD. These extended data support the notion that people with larger lungs have bigger alveoli and that this anatomic
–500
HU mean
–600
–700
–800
–900
–1,000
0
1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 11,000 total lung air volume (mL)
Figure 1 – Brown et al1 mean lung density (HU) and lung volume continuum. Blue circles ¼ subjects with COPD; gray circles ¼ subjects without COPD; and red circles ¼ additional free diving subjects. HU ¼ Hounsfield unit.
journal.publications.chestnet.org
291