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Hypoxemia: Don't Take It Lying Down! How to Detect Platypnea-Orthodeoxia Syndrome and What to Do About It
Canadian Journal of Cardiology 32 (2016) 294e295
Editorial
Hypoxemia: Don’t Take It Lying Down! How to Detect Platypnea-Orthodeoxia Syndrome and What to Do About It Warwick Butt, FRACP, FCICM Intensive Care Unit, Royal Childrens Hospital, Melbourne, Victoria, Australia; University of Melbourne, Melbourne, Victoria, Australia; Murdoch Childrens Research Institute, Parkville, Victoria, Australia
See article by Rochlani et al., pages 395.e1-395.e3 of this issue. Hypoxemia is an important clinical finding that is often manifested by some form of respiratory difficulty (tachypnea or dyspnea) and arterial desaturation. An accurate diagnosis is essential for the correct management of the patient. There are many causes, including diseases of the lung, pulmonary vasculature, and heart. As all medical students are taught, diagnosis is usually established by history and clinical examination and is confirmed by appropriate investigations. Errors occur when an incorrect diagnosis leads to incorrect management. In this issue of the Canadian Journal of Cardiology, Rochlani et al.1 present an unusual case of a 72-year-old woman in whom unilateral diaphragmatic palsy (UDP) developed, with desaturation, dyspnea, and impaired function after laparoscopic Nissen fundoplication. She was treated with oxygen and discharged home. Two months later she presented at a cardiology clinic, where a diagnosis of platypneaorthodeoxia syndrome (POS) was made; it was appropriately treated, and the patient recovered. There are a number of questions that merit consideration in the journey of this patient. Was the initial diagnosis of the cause of her desaturation correct, and what lessons can we learn? Was the care delivered to this patient ideal, and what does this case show about how the system of health care impacts health outcomes? How common is this condition of platypneaorthodeoxia? What did the investigations reveal about the pathophysiology of this condition? Under what conditions does a probe-patent foramen ovale (PFO) shunt right to left? What are the indications for device closure of a PFO? Impairment of diaphragmatic function is uncommon but has been described after Nissen fundoplication,2 although UDP is rare. UDP, in the absence of extensive atelectasis or pneumonia, causes desaturation only in small infants or adults with coexisting pulmonary disease or neuromuscular weakness
Received for publication September 4, 2015. Accepted September 11, 2015. Corresponding author: Dr Warwick Butt, Royal Childrens Hospital Flemington Road, Parkville, Victoria 3052, Australia. E-mail: [email protected] See page 295 for disclosure information.
or during sleep.3-5 Hence, UDP is unlikely to be a cause of this patient’s desaturation. It was an apparent and obvious provisional diagnosis made on the basis of chest radiographic changes and desaturation. However, one would expect her dyspnea and desaturation, if caused by atelectasis and UDP, to improve with 5 L of oxygen through an intranasal catheter and possibly her symptoms to also improve by being out of bed and sitting and standing. She was discharged home on oxygen therapy, without an established diagnosis and no apparent response of her desaturation and dyspnea. Presumably some follow-up visit occurred, either with the surgeon or the initial referring physician, but it is clearly less than ideal that over the next 2 months, the patient had a substantial loss of function and ongoing dyspnea and desaturation on standing. The health system failed her. Worldwide, there are 2 fundamental systems of health care; public or government systems (similar to the National Health Scheme in the United Kingdom or Medicare in Canada) or privatized systems (with or without managed care) prevalent in the United States and some parts of Europe. Both systems have strengths and weaknesses, with the government system providing universal access, although not always in a timely manner, and the private system purportedly providing better quality and timely access to those who can pay.6 There is, however, much variability across all systems. There is good evidence that integrated health care delivery systems can be very effective at a population level, but unfortunately these too often do not succeed.7 Some countries such as Australia have a combination of both private and public systems, but care is often fragmented and difficult to improve.8 However, it is important that continued reform and evaluation of systems of care occur, because these health systems can significantly influence patient outcome; eg, cancer outcomes are dramatically impacted by health care systems in 3 key ways: coverage, innovation, and quality of care.9 This patient’s presentation 2 months after discharge from the hospital on home oxygen, with ongoing dyspnea and desaturation that was worse when standing and better when lying supine, establishes the clinical diagnosis of POS; all other cardiopulmonary causes of dyspnea and desaturation will either not change or worsen in a supine position.10,11 A
http://dx.doi.org/10.1016/j.cjca.2015.09.004 0828-282X/Ó 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Warwick Butt Hypoxemia: Don’t Take It Lying Down!
computed tomographic (CT) angiogram was obtained; this is necessary to exclude not only lung pathology and pulmonary emboli but also pulmonary arteriovenous malformation, which has been reported as a cause of POS.12 A transthoracic echocardiogram revealed PFO and a right-to-left shunt with saline injection. Cardiac catheterization importantly showed no evidence of right ventricular dysfunction; right atrial pressures were lower than left atrial pressures, and there was no evidence of a ventricular septal defect. Balloon occlusion of the PFO confirmed that it was safe to proceed to device closure. It is important to remember when choosing a device rather than surgery for closure of a PFO or atrial septal defect that there must be adequate tissue margins around the hole for accurate and secure deployment of the device. Occasionally, if the hole is eccentric or very large, surgery may be required. Other indications for closure of an atrial septal defect or PFO are well established, namely, systemic emboli, stroke, or a leftto-right shunt of hemodynamic significance.13 Migraine headaches have also been associated with a PFO. Once the diagnosis has been established clinically, investigations are performed to confirm the diagnosis and establish a management plan. It would have been of great interest to document with transthoracic echocardiography (TTE) the amount of change in blood flow or intracardiac shunting with changes in patient position; also a CT scan in the supine position may have revealed a different amount of right-to-left shunting across the PFO when intravenous contrast medium was administered to the patient through an arm vein and then a leg vein. These are clearly of academic rather interest rather than of relevance to the patient’s management plan, especially given the history and saturation measurements in the supine and prone positions. There have now been nearly 200 POS cases reported. In a major review, Rodrigues et al.14 highlighted the diversity of conditions that are associated with POS and advocated percutaneous device closure based on safety and efficacy. It is important to recognize the many clinical situations that will cause a probe-patent foramen ovale to “stretch” and allow right-to-left shunting if right atrial pressure is greater than left atrial pressure or if inferior vena caval blood flow is directed toward this now patent foramen. This can occur in a number of clinical situations including any form of isolated right heart failure, both primary caused by ischemic heart disease and cardiomyopathy as well as secondary resulting from pneumonia, pulmonary hypertension, or left heart failure. Many types of thoracic or abdominal surgery will lead to distortion of normal cardiac or mediastinal anatomy, allowing inferior vena caval blood to be directed, with or without a prominent Eustachian valve, toward the fossa ovalis. As we know, routine post mortem studies show a 27% incidence of probe-patent foramen ovale,15 and thus it is likely that the number of POS cases will continue to increase because of increased awareness by clinicians, the availability of echocardiographic diagnosis, and an increase in the number and type of surgical
295
procedures being performed for many pulmonary, aortic, hepatic, and gastrointestinal conditions. Fortunately, POS is easily diagnosed clinically with a careful and thorough history of positional hypoxemia and dyspnea that improves on lying down, and this condition can be readily confirmed with TTE. Once diagnosed, cardiac catheterization and device closure is usually curative. Disclosures The author has no conflicts of interest to disclose. References 1. Rochlani Y, Vallurupalli S, Hakeem A, et al. Refractory hypoxemia after laparoscopic Nissen fundoplication. Can J Cardiol 2016;32:395.e1-3. 2. Anvari M, Allen C, Moran LA. Immediate and delayed effects of fundoplication on pulmonary function. Surg Endosc 1996;10:1171-5. 3. Riley E. Idiopathic diaphragmatic paralysis. A report of eight cases. Am J Med 1962;32:404-16. 4. Laroche C, Carroll N, Moxham J, et al. Clinical significance of severe isolated diaphragm weakness. Am Rev Respir Dis 1988;138:862-6. 5. Baltzan MA, Scott AS, Wolkove N. Unilateral hemidiaphragm weakness is associated with positional hypoxemia in REM sleep. J Clin Sleep Med 2012;8:51-8. 6. Rice T, Rosenau P, Unruh LY, et al. United States of America: health system review. Health Syst Transit 2013;15:1-431. 7. Bevan G, Janus K. Why hasn’t integrated health care developed widely in the United States and not at all in England. J Health Polit Policy Law 2011;36:141-64. 8. Hall Jane. Australian Health Caredthe challenge of reform in a fragmented system. N Engl J Med 2015;373:493-7. 9. Karanikolos M, Ellis L, Coleman MP, McKee M. Health systems performance and cancer outcomes. J Natl Cancer Inst 2013;2013:7-12. 10. Kubler P, Gibbs H, Garrahy P. Platypnea-orthodeoxia syndrome. Heart 2000;83:221-3. 11. Seward J, Hayes D, Smith J, et al. Platypnea-orthodeoxia: clinical profile, diagnostic workup, management, and report of 7 cases. Mayo Clin Proc 1984;59:221-31. 12. Anderson M, Wayangankar S, Selby G. Pulmonary arteriovenous malformations presenting as platypnea-orthodeoxia in graft-versus-host disease. Echocardiography 2014;31:E145-6. 13. Cheng TO. Patent foramen ovale: to close or not to close remains an unsettled issue except in three conditions. Int J Cardiol 2014;177:320-1. 14. Rodrigues P, Palma P, Sousa-Pereira L. Platypnea-orthodeoxia syndrome in review: defining a new disease? Cardiology 2012;123:15-23. 15. Hagen P, Scholz D, Edward W. Incidence and size of patent foramen ovale during the first 10 decades of life: an autopsy of 965 normal hearts. Mayo Clin Proc 1984;59:17-20.
Editorial
Hypoxemia: Don’t Take It Lying Down! How to Detect Platypnea-Orthodeoxia Syndrome and What to Do About It Warwick Butt, FRACP, FCICM Intensive Care Unit, Royal Childrens Hospital, Melbourne, Victoria, Australia; University of Melbourne, Melbourne, Victoria, Australia; Murdoch Childrens Research Institute, Parkville, Victoria, Australia
See article by Rochlani et al., pages 395.e1-395.e3 of this issue. Hypoxemia is an important clinical finding that is often manifested by some form of respiratory difficulty (tachypnea or dyspnea) and arterial desaturation. An accurate diagnosis is essential for the correct management of the patient. There are many causes, including diseases of the lung, pulmonary vasculature, and heart. As all medical students are taught, diagnosis is usually established by history and clinical examination and is confirmed by appropriate investigations. Errors occur when an incorrect diagnosis leads to incorrect management. In this issue of the Canadian Journal of Cardiology, Rochlani et al.1 present an unusual case of a 72-year-old woman in whom unilateral diaphragmatic palsy (UDP) developed, with desaturation, dyspnea, and impaired function after laparoscopic Nissen fundoplication. She was treated with oxygen and discharged home. Two months later she presented at a cardiology clinic, where a diagnosis of platypneaorthodeoxia syndrome (POS) was made; it was appropriately treated, and the patient recovered. There are a number of questions that merit consideration in the journey of this patient. Was the initial diagnosis of the cause of her desaturation correct, and what lessons can we learn? Was the care delivered to this patient ideal, and what does this case show about how the system of health care impacts health outcomes? How common is this condition of platypneaorthodeoxia? What did the investigations reveal about the pathophysiology of this condition? Under what conditions does a probe-patent foramen ovale (PFO) shunt right to left? What are the indications for device closure of a PFO? Impairment of diaphragmatic function is uncommon but has been described after Nissen fundoplication,2 although UDP is rare. UDP, in the absence of extensive atelectasis or pneumonia, causes desaturation only in small infants or adults with coexisting pulmonary disease or neuromuscular weakness
Received for publication September 4, 2015. Accepted September 11, 2015. Corresponding author: Dr Warwick Butt, Royal Childrens Hospital Flemington Road, Parkville, Victoria 3052, Australia. E-mail: [email protected] See page 295 for disclosure information.
or during sleep.3-5 Hence, UDP is unlikely to be a cause of this patient’s desaturation. It was an apparent and obvious provisional diagnosis made on the basis of chest radiographic changes and desaturation. However, one would expect her dyspnea and desaturation, if caused by atelectasis and UDP, to improve with 5 L of oxygen through an intranasal catheter and possibly her symptoms to also improve by being out of bed and sitting and standing. She was discharged home on oxygen therapy, without an established diagnosis and no apparent response of her desaturation and dyspnea. Presumably some follow-up visit occurred, either with the surgeon or the initial referring physician, but it is clearly less than ideal that over the next 2 months, the patient had a substantial loss of function and ongoing dyspnea and desaturation on standing. The health system failed her. Worldwide, there are 2 fundamental systems of health care; public or government systems (similar to the National Health Scheme in the United Kingdom or Medicare in Canada) or privatized systems (with or without managed care) prevalent in the United States and some parts of Europe. Both systems have strengths and weaknesses, with the government system providing universal access, although not always in a timely manner, and the private system purportedly providing better quality and timely access to those who can pay.6 There is, however, much variability across all systems. There is good evidence that integrated health care delivery systems can be very effective at a population level, but unfortunately these too often do not succeed.7 Some countries such as Australia have a combination of both private and public systems, but care is often fragmented and difficult to improve.8 However, it is important that continued reform and evaluation of systems of care occur, because these health systems can significantly influence patient outcome; eg, cancer outcomes are dramatically impacted by health care systems in 3 key ways: coverage, innovation, and quality of care.9 This patient’s presentation 2 months after discharge from the hospital on home oxygen, with ongoing dyspnea and desaturation that was worse when standing and better when lying supine, establishes the clinical diagnosis of POS; all other cardiopulmonary causes of dyspnea and desaturation will either not change or worsen in a supine position.10,11 A
http://dx.doi.org/10.1016/j.cjca.2015.09.004 0828-282X/Ó 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Warwick Butt Hypoxemia: Don’t Take It Lying Down!
computed tomographic (CT) angiogram was obtained; this is necessary to exclude not only lung pathology and pulmonary emboli but also pulmonary arteriovenous malformation, which has been reported as a cause of POS.12 A transthoracic echocardiogram revealed PFO and a right-to-left shunt with saline injection. Cardiac catheterization importantly showed no evidence of right ventricular dysfunction; right atrial pressures were lower than left atrial pressures, and there was no evidence of a ventricular septal defect. Balloon occlusion of the PFO confirmed that it was safe to proceed to device closure. It is important to remember when choosing a device rather than surgery for closure of a PFO or atrial septal defect that there must be adequate tissue margins around the hole for accurate and secure deployment of the device. Occasionally, if the hole is eccentric or very large, surgery may be required. Other indications for closure of an atrial septal defect or PFO are well established, namely, systemic emboli, stroke, or a leftto-right shunt of hemodynamic significance.13 Migraine headaches have also been associated with a PFO. Once the diagnosis has been established clinically, investigations are performed to confirm the diagnosis and establish a management plan. It would have been of great interest to document with transthoracic echocardiography (TTE) the amount of change in blood flow or intracardiac shunting with changes in patient position; also a CT scan in the supine position may have revealed a different amount of right-to-left shunting across the PFO when intravenous contrast medium was administered to the patient through an arm vein and then a leg vein. These are clearly of academic rather interest rather than of relevance to the patient’s management plan, especially given the history and saturation measurements in the supine and prone positions. There have now been nearly 200 POS cases reported. In a major review, Rodrigues et al.14 highlighted the diversity of conditions that are associated with POS and advocated percutaneous device closure based on safety and efficacy. It is important to recognize the many clinical situations that will cause a probe-patent foramen ovale to “stretch” and allow right-to-left shunting if right atrial pressure is greater than left atrial pressure or if inferior vena caval blood flow is directed toward this now patent foramen. This can occur in a number of clinical situations including any form of isolated right heart failure, both primary caused by ischemic heart disease and cardiomyopathy as well as secondary resulting from pneumonia, pulmonary hypertension, or left heart failure. Many types of thoracic or abdominal surgery will lead to distortion of normal cardiac or mediastinal anatomy, allowing inferior vena caval blood to be directed, with or without a prominent Eustachian valve, toward the fossa ovalis. As we know, routine post mortem studies show a 27% incidence of probe-patent foramen ovale,15 and thus it is likely that the number of POS cases will continue to increase because of increased awareness by clinicians, the availability of echocardiographic diagnosis, and an increase in the number and type of surgical
295
procedures being performed for many pulmonary, aortic, hepatic, and gastrointestinal conditions. Fortunately, POS is easily diagnosed clinically with a careful and thorough history of positional hypoxemia and dyspnea that improves on lying down, and this condition can be readily confirmed with TTE. Once diagnosed, cardiac catheterization and device closure is usually curative. Disclosures The author has no conflicts of interest to disclose. References 1. Rochlani Y, Vallurupalli S, Hakeem A, et al. Refractory hypoxemia after laparoscopic Nissen fundoplication. Can J Cardiol 2016;32:395.e1-3. 2. Anvari M, Allen C, Moran LA. Immediate and delayed effects of fundoplication on pulmonary function. Surg Endosc 1996;10:1171-5. 3. Riley E. Idiopathic diaphragmatic paralysis. A report of eight cases. Am J Med 1962;32:404-16. 4. Laroche C, Carroll N, Moxham J, et al. Clinical significance of severe isolated diaphragm weakness. Am Rev Respir Dis 1988;138:862-6. 5. Baltzan MA, Scott AS, Wolkove N. Unilateral hemidiaphragm weakness is associated with positional hypoxemia in REM sleep. J Clin Sleep Med 2012;8:51-8. 6. Rice T, Rosenau P, Unruh LY, et al. United States of America: health system review. Health Syst Transit 2013;15:1-431. 7. Bevan G, Janus K. Why hasn’t integrated health care developed widely in the United States and not at all in England. J Health Polit Policy Law 2011;36:141-64. 8. Hall Jane. Australian Health Caredthe challenge of reform in a fragmented system. N Engl J Med 2015;373:493-7. 9. Karanikolos M, Ellis L, Coleman MP, McKee M. Health systems performance and cancer outcomes. J Natl Cancer Inst 2013;2013:7-12. 10. Kubler P, Gibbs H, Garrahy P. Platypnea-orthodeoxia syndrome. Heart 2000;83:221-3. 11. Seward J, Hayes D, Smith J, et al. Platypnea-orthodeoxia: clinical profile, diagnostic workup, management, and report of 7 cases. Mayo Clin Proc 1984;59:221-31. 12. Anderson M, Wayangankar S, Selby G. Pulmonary arteriovenous malformations presenting as platypnea-orthodeoxia in graft-versus-host disease. Echocardiography 2014;31:E145-6. 13. Cheng TO. Patent foramen ovale: to close or not to close remains an unsettled issue except in three conditions. Int J Cardiol 2014;177:320-1. 14. Rodrigues P, Palma P, Sousa-Pereira L. Platypnea-orthodeoxia syndrome in review: defining a new disease? Cardiology 2012;123:15-23. 15. Hagen P, Scholz D, Edward W. Incidence and size of patent foramen ovale during the first 10 decades of life: an autopsy of 965 normal hearts. Mayo Clin Proc 1984;59:17-20.