Is this factitious pt being managed appropriately? Was his using supplemental oxygen w/ BiPAP appropriate to correct his pt's low SaO2 by increasing alveolar recruitment, or would a blood transfusion be more appropriate? Would the sildenafil dilate the pulmonary artery and aorta? Would the low dose digitoxin be effective in increasing the pt's LVEF and cardiac function? Was the GP's assesment and diagnosis correct? Did he not run any tests that should've been run? Should the pt be referred to an interventional cardiologist for repairing of the VSD?

Thanks!


Dear Doctor:
Re: Danielle Kraulitz Sartorius
My patient is a 28-year-old female biomedical researcher. She is an avid bodybuilder and sculler, having won several amateur competitions in both. She does not smoke or use illegal drugs, although she admits to very rarely drinking alcohol, as well as using creatine monohydrate to increase her muscle mass. She weighs 185lbs, is 6’1”, and has a body fat percentage of 6%. She eats a balanced diet of 3000 calories per day. She is not on any medications, save for albuterol and fluticasone for asthma. Her grandfather has AF, which is well controlled by sotalol. She has no major medical history, save for a laparoappendectomy when she was 14.

For the past two months, she has been complaining of dyspnea –which was at 4-6 breaths/min--, mild-to-moderate angina which gets worse on exertion, occasional breathlessness, fatigue, palpitations, grayouts, headaches, nausea, a dry cough, peripheral paresthesia, myalgia, and a low-grade fever of 37.6 degrees C. She has a grade 3-4 heart murmur, and her lung sounds are deep, slightly moist, and strained. I ordered a CBC and CMP, for these are standing orders for all new patients; on the CBC, a MCV of 110 fL, a MCHC of 32 g/dL, a MCH of 36 pg/RBC, a Hb of 20.8 g/dL, and a Hct of 65%; WBC was on the high end of normal, save for the eosinophil count, which was at 3750. Serum iron was 160 mcg/dL, TIBC was 320 mcg/dL, and transferrin saturation was 50%. CMP was within normal range, though the bicarbonate was 13.5 mmol/L, the lactate was 30 mg/dL, the potassium was at 6 mmol/L, the BUN was 32 mg/dL, and the serum creatinine was 0.3 mg/dL. ABG indicated that PaCO2 was 60.0 mmHg, PaO2 was 30.0 mmHg, SaO2 is 45%, A-a gradient was 45 mmHg, shunt fraction was 68%, HCO3 was 18.4 mmol/L, pH was 7.1, and SBE was –10.1 mmol/L. Total CK is at 292.5 ng/mL. AST is at 52.5 U/L. LDH is at 427.5 U/L. Her CRP was 175 mg/dL. A CXR showed what appeared to be pulmonary fibrosis and/or inflammation. A TTE indicated endocarditis, as well as unequal BVH, predominately LVH, and a small, presumably congenital VSD; pulmonary and aortic valve stenosis was also present, with the stenosis of the pulmonary valve being worse, LVEF was 40%, RVEF was 30%, stroke volume was 100 mL. Her bp is 119/49 mmHg, and her pulse is 90 beats/min. An EKG revealed a mild first-degree AV block, and a QTc of 470 ms. An ELISA for all common bacteria and viruses came back negative.

My impression is that there is some kind of pathologic inflammatory process, presumably caused by the eosinophilia, which is attacking the heart, lungs, and muscles, causing a metabolic acidosis, which, due to the lung damage, is not being compensated due to the fact that there is respiratory acidosis present. The metabolic acidosis is made evident by her Kussmaul respirations, and confirmed by her arterial blood gases; her high lactate is also confirmatory of metabolic acidosis and poor tissue oxygenation. Her respiratory acidosis is most likely due to her lung damage. The peripheral paresthesia and nausea are likely due to the acidosis as well. The inflammation is most clearly indicated by the elevated CRP, which is 17.5x normal. The elevated RBC indices are most likely an attempt to compensate for the hypoxemia, but perhaps could also be due to her lifestyle of strenuous exercise; they, along with her iron panel, also rule out anemias as the cause of her poor oxygenation, although her blood gases speak for themselves, for all that her CBC shows is that her blood gases are fully capable of being optimally utilized. Which is happening, for I have calculated her arterial oxygen content, which is 12.63%, which is very hypoxemic, but still not as severe as it would be if she did not have the relatively high hemoglobin and hematocrit. However, her currently high cardiac output also plays a role in the true severity of her hypoxia, for I have calculated her oxygen delivery, and it is 1136.70 mL/min, which is just 80.70% of her normal resting oxygen delivery, which, using a heart rate of 50 beats/min and an CaO2 of 28.17%, comes out to be 1408.5 mL/min; her heart has compensated remarkably well as well. The lung inflammation and fibrosis most likely caused the physiologic shunt, indicating that the inflammation and fibrosis is rendering 68% of alveoli useless for gas exchange. The BVH most likely is the direct result of the valve stenoses, which are most likely the direct result of inflammation and hypoxemia. There could be a right-to-left shunt present as well, due to the positive pressure gradient between the pulmonary artery and the aorta, plus the VSD, which apparently was asymptomatic until the stenoses caused a pressure gradient large enough to cause symptoms; this explains her low oxygen delivery and LVH. Her exertion-induced dyspnea, occasional breathlessness, and LVH are consistent with secondary-to-hypoxemia pulmonary arterial hypertension. The somewhat low LVEF, presumably caused by the LVH and aortic stenosis, is contributing to her hypoxemia, for there is less blood being pumped through the aorta. Therefore, she has subacute left heart failure caused by subacute aortic insufficiency, along with PAH. Her aortic insufficiency is probably causing her low diastolic and high pulse pressure. The prolonged QTc is worrisome. Her high BUN, CK, and liver enzymes are reflective as well of the protein breakdown the runaway inflammation is causing. She has remarkable kidney function, considering that I have estimated her creatinine clearance at 369.83 mL/min, which could be due to a combination of her lifestyle of strenuous exercise and her current muscular breakdown, and her glomerular filtration rate at 281.54 mL/min; I have confirmation from her previous GP that this is apparently her baseline. Also her BUN:Cr ratio is at 106.67 with below normal serum creatinine, making it clear that her elevated BUN is due solely to the muscle damage, although she will have to be watched for evidence of renal damage. My diagnosis as of yet is Churg-Strauss Syndrome, based on her eosinophilia and history of asthma.

Accordingly, I have advised her to abstain from strenuous activity, and I have prescribed supplemental oxygen with BiPAP during sleep, in order to attempt to increase her oxygenation, reduce her shunt fraction, and reduce the strain on her taxed respiratory and cardiovascular systems. I have also prescribed sildenafil to dilate her aorta and pulmonary artery, and low dose digitoxin to increase her LVEF. Additionally, I have also prescribed oral mycophenolate and dexamethasone, in order to reduce the inflammation and eosinophilia.


I would greatly appreciate you seeing her, and advising me on her management, for her complicated case requires a more skilled physician than I.

Sincerely,
Dr Thomas Blalock Taussig MBChB MRCGP