Flat Out Odd
Answer: C
This woman presents to the ED with a common complaint – shortness of breath – that may be caused by a variety of circumstances or may be multi-factorial in nature.
The time course, lung sounds, and peripheral edema may be consistent with congestive heart failure (A), while her elevated temperature and breath sounds may lead the physician to believe that she has developed pneumonia (B). An acute worsening of symptoms in a smoker may prompt the clinician to consider a complication of COPD: pneumothorax (D).
While there is considerable overlap in signs and symptoms with many of these conditions, our patient exhibits two less common but very important findings: platypnea and orthodeoxia.
Platypnea [Gr: platy-, flat; -pnea, breathing] is shortness of breath relieved by lying down (contrast this to orthopnea: ortho-, straight/upright; -pnea, breathing); i.e. the patient breathes better lying flat.
Orthodeoxia [Gr: ortho-, straight/upright; -deoxia, lacking oxygen] is a drop in oxygen saturation provoked or worsened by sitting or standing up straight (in contrast to lying down).
While many things may cause dyspnea [Gr: dys-, altered/abnormal; -pnea, breathing], the platypnea-orthpdeoxia
syndrome is mostly caused by one of two things:
● Cardiac shunt – most commonly by pulmonary embolism (this syndrome has also been described in
other shunts such as a patent foramen ovale and atrial septal defect)
● Hepatopulmonary syndrome – high levels of circulating nitric oxide (due to poor hepatic clearance)
cause dilation in the microvasculature and render them unable to respond to changes in postural tone
With this information, we can narrow the differential diagnosis substantially, consider starting empiric treatment, confirm the diagnosis, and verify the extent of the pulmonary embolism (i.e. presence of right heart strain).
Bottom line:
● When a patient is less short of breath and has better oxygen saturations while lying down and
worsening signs and symptoms sitting up, consider the platypnea-orthodeoxia syndrome.
● If your patient does not have obvious liver failure, think PE.
References
Brunner M, Tapson V. Platypnea-orthodeoxia: bilateral lower-lobe pulmonary emboli and review of associated pathophysiology and management. South Med J. 2011;104:215-221.
Kubler P, Gibbs H, Garrahy P. Platypnoea–orthodeoxia syndrome. Heart. 2000;83:221-223.
Rosei EA, Muiesan ML. Platypnea and orthodeoxia in a patient with pulmonary embolism. Am J Emerg Med. 2013; 760.e1–760.e2
This woman presents to the ED with a common complaint – shortness of breath – that may be caused by a variety of circumstances or may be multi-factorial in nature.
The time course, lung sounds, and peripheral edema may be consistent with congestive heart failure (A), while her elevated temperature and breath sounds may lead the physician to believe that she has developed pneumonia (B). An acute worsening of symptoms in a smoker may prompt the clinician to consider a complication of COPD: pneumothorax (D).
While there is considerable overlap in signs and symptoms with many of these conditions, our patient exhibits two less common but very important findings: platypnea and orthodeoxia.
Platypnea [Gr: platy-, flat; -pnea, breathing] is shortness of breath relieved by lying down (contrast this to orthopnea: ortho-, straight/upright; -pnea, breathing); i.e. the patient breathes better lying flat.
Orthodeoxia [Gr: ortho-, straight/upright; -deoxia, lacking oxygen] is a drop in oxygen saturation provoked or worsened by sitting or standing up straight (in contrast to lying down).
While many things may cause dyspnea [Gr: dys-, altered/abnormal; -pnea, breathing], the platypnea-orthpdeoxia
syndrome is mostly caused by one of two things:
● Cardiac shunt – most commonly by pulmonary embolism (this syndrome has also been described in
other shunts such as a patent foramen ovale and atrial septal defect)
● Hepatopulmonary syndrome – high levels of circulating nitric oxide (due to poor hepatic clearance)
cause dilation in the microvasculature and render them unable to respond to changes in postural tone
With this information, we can narrow the differential diagnosis substantially, consider starting empiric treatment, confirm the diagnosis, and verify the extent of the pulmonary embolism (i.e. presence of right heart strain).
Bottom line:
● When a patient is less short of breath and has better oxygen saturations while lying down and
worsening signs and symptoms sitting up, consider the platypnea-orthodeoxia syndrome.
● If your patient does not have obvious liver failure, think PE.
References
Brunner M, Tapson V. Platypnea-orthodeoxia: bilateral lower-lobe pulmonary emboli and review of associated pathophysiology and management. South Med J. 2011;104:215-221.
Kubler P, Gibbs H, Garrahy P. Platypnoea–orthodeoxia syndrome. Heart. 2000;83:221-223.
Rosei EA, Muiesan ML. Platypnea and orthodeoxia in a patient with pulmonary embolism. Am J Emerg Med. 2013; 760.e1–760.e2