Rare Lung Disease Symptoms Mimic Asthma
By Margaret Varnell, RN, RRT
Lymphangiolieomyomatosis (LAM), a rare lung disease affecting women of childbearing years, may in many cases be undiagnosed or misdiagnosed as asthma, delaying what care is available.
There are 250 known cases of LAM in the United States; but because of diagnostic problems, conservative estimates suggests there may actually be as many as three times that number of women with the disease.
Most patients present with dyspnea on exertion, chest pain and occasional episodes of hemoptysis. The most dramatic presentation includes recurrent pleural effusions and pneumothoraces. The illness becomes progressive.
INVESTIGATORS don’t know the etiology of the illness. An open lung biopsy is one method of diagnosing the condition. Samples examined microscopically reveal infiltration of the pulmonary parenchyma by smooth muscle tissue. The muscle cells then form bundles and eventually group into cysts. Although a chest X-ray may show cystic changes, computerized tomography (CT) is the more definitive diagnostic tool.
Cysts appear on a CT scan in the form of blebs or holes. Diagnosis of LAM can also be done by thoroscopy. The cysts are usually seen via an endoscope as evenly dispersed across the lung tissue.
Current LAM research is focusing on two fronts. First, because the illness affects women of childbearing years, there is a question of whether estrogen and other female hormones may be a factor. The second focus is whether there is a possible link between LAM and a benign kidney tumor called angiomyolipoma (AML), since about 50 percent of such tumors occur simultaneously with LAM.
ALTHOUGH PATIENTS studied to date have not demonstrated a hormonal abnormality, the correlation between the patient population affected is still being examined. A genetic origin for LAM has likewise not yet been ruled out.
Because LAM is generally misdiagnosed as asthma, LAM patients are usually given a course of bronchodilator therapy initially. But as the illness progresses, patients are less and less responsive to the drug regimen, prompting a closer inspection for something besides asthma.
Once LAM is diagnosed, most treatment regimens have focused on the reduction of estrogen in an attempt to slow the progress of the muscle fiber growth. This can be done either by removal of the patient’s ovaries or by pharmaceutically supplementing the patient’s progesterone. Neither course of therapy has been definitive.
In extreme cases, lung transplant therapy has been attempted, but that surgery is not without consequences, since the recurrence of LAM in newly transplanted lungs has been reported.
TO DEMONSTRATE what caregivers face in diagnosing LAM and working with the patients
after diagnosis, here is a case study of one LAM patient.
“Mary,” now age 54 years, was diagnosed with LAM in 1994 by retroperitoneal lymph node biopsy. She has a history of recurrent pleural effusions and multiple thin-walled cystic lesions bilaterally.
Her past medical history includes a total hysterectomy in 1991 and a thoracotomy and partial pleurectomy in 1994.
She was examined at the National Institutes of Health (NIH) in Bethesda, Md., in March 1996, and found to have clear breath sounds and no apparent dyspnea.
Her ABG on room air at that time was pH 7.45; PcO2 29; PO2 90. Bronchoalveolar lavages taken during bronchoscopy revealed normal flora. No endobronchial lesions were noted.
Her pulmonary function study did not revel an obstructive or a restrictive process. However, a mild to moderate reduction in her carbon monoxide diffusion capacity was noted. A CT of her chest revealed multiple small cystic lesions bilaterally in the lower half of her lung fields. Her chest X-ray revealed no pleural effusions and no pneumothorax.
She is being maintained on Os-Cal 500 mg BID and Depo-Provera 250 mg IM once a month. NIH physicians recommended the addition of Pneumovax to her drug regimen. She is clinically stable at this time.
Although they are a relatively small group, LAM patients are not alone in their battle. A national organizationLAM Foundation, headquartered in Cincinnati, Ohiohas been established. The group offers literature and support services to patients and their caregivers alike.
The group has studies ongoing, funded by the National Heart, Lung and Blood Institute. But because the research is still in preliminary stages, no reportable data are yet available.
LAM is just what we needed in the respiratory care arena today, right! Asthma is hard enough to get a handle on and manage. Now RCPs have an illness that mimics asthma and may be more common than originally thought.
* About the author: Margaret Varnell, New Orleans, is a practitioner and freelance writer.
* To reach the LAM Foundation, call (513) 777-6889.
New Antibiotic Holds Promise, Studies Show
Synercid® (quinupristin/dalfopristin), an investigational antibiotic, appears to be a promising new treatment for potentially life-threatening infections caused by bacteria that resist many available therapies, according to research presented during a scientific symposium at the 20th International Congress of Chemotherapy held in Sydney, Australia earlier this year.
New clinical data on the first injectable streptogramin antibiotic has been made available as infectious disease specialists struggle against the escalating, global threat of Gram-positive antibiotic resistance.
The rise of vancomycin-resistant Enterococcus faecium (VREF) infections has proven increasingly challenging to physicians in selecting appropriate antibiotics.
Robert C. Moellering, MD, of Harvard Medical School, Boston, reported on the safety and efficacy of Synercid in severely ill patients, such as those who have undergone organ transplantation, hematologic disorders, mechanical ventilation or dialysis.
There was a clinical response rate (cure and improvement) of 73.8 percent in 195 clinically evaluable patients, and a bacteriologic response rate (pathogens eradicated and presumed eradicated) of 70.9 percent, he said.
Joint pain was the most common adverse effect, noted in 11.3 percent of the patients.
Reporting the results of a comparative study conducted in 74 investigational sites in France, Germany, Spain, Sweden and the United States, Jean-Yves Fagon, MD, of the Hopital Broussais-University, Paris, found an overall clinical response rate of 56.3 percent with Synercid-treated patients versus 58.3 percent in those who received vancomycin.
In patients who were intubated at entry into the study, the response rates were 54.2 percent and 53.7 percent respectively.
Among patients with S. aureus infections, the eradication rates were 57.7 percent for Synercid and 60 percent for vancomycin. Slightly more than 15 percent of patients discontinued treatment with Synercid due to an adverse event.
