: l e

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obstruction. Because of the irregular rhythm, the redundant (and unresected) anterior mitral valve leaflet may be in a more open position at the time of ventricular systole, predisposing to an enhanced Venturi effect and hence greater obstruction. Since drug therapy, heart rate , blood pressure, body position (at the time of echocardiogram), and volume status were similar at the time of both studies, it is unlikely that these mechanisms can be invoked as the source of our observations.

1

REFERENCES

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FIGURE 2. Improvement in systolic anterior motion of the mitral valve in sinus rhythm. Average heart rate, 84 beats/min; left ventricular diastolic dimension, 5.2 em; left ventricular outflow tract early systolic dimension, 2.4 em . anterior motion of the mitral valve (Fig 1) and left ventricular outflow obstruction with peak gradient of74 mm Hg, mean gradient of 41 mm Hg, and trace mitral regurgitation. Systolic anterior motion and left ventricular outflow tract gradients were compared between varying RR intervals and no significant correlation was found . In the next 2 h, the rhythm converted spontaneously to sinus rhythm with a mean rate of 841m in. The patient's volume status and weight remained unchanged over the ensuing 24 h. A repeat echoDoppler study was performed 24 h after the initial identification of left ventricular outflow tract obstruction. Chamber sizes and function were comparable; mild systolic anterior motion was again present; however, it was much less prominent than on the previous study (Fig 2). The left ventricular outflow tract peak gradient was 12 mm Hg. Mild mitral regurgitation was noted . The medications were changed to disopyramide phosphate (Norpace) and atenolol; digoxin and quinidine therapy was discontinued. A six-week postdischarge echocardiogram done in sinus rhythm with heart rate of 70 beats/min revealed no evidence of outflow obstruction. DISCUSSION

Since the advent of mitral valvuloplasty using the Carpentier ring,' hundreds of patients have undergone repair with this technique. Left ventricular outflow obstruction complicating Carpentier ring mitral valvuloplasty has been reported by several investigators.I.' The proposed mechanisms for the finding of left ventricular outflow tract obstruction include inhibition of the normal posterior systolic motion of the mitral valve by the semirigid Carpentier ring, reduction in left ventricular volume following correction of the mitral regurgitation, decrease in left ventricular outflow dimensions,•.•.5 redundancy of the mitral leaflets, and inability of the mitral annulus to move posteriorly due to the rigid ring.1.O We report a single case of significant change in systolic anterior motion and left ventricular outflow tract obstruction apparently related to rhythm change from atrial fibrillation to normal sinus rhythm. Possible mechanisms for this difference remain obscure . It is possible that the atrial fibrillation rhythm itself may produce some unusual dynamic anterior motion of the mitral valve in systole, leading to outflow tract

1 Schiavone WA, Cosgrove DM, Lever HM, Stewart WJ, Calcedo EE. Long-term follow up of patients with left ventricular outflow tract obstruction after Carpentier ring mitral valvuloplasty. Circulation 1988; 78(suppll):fi0.65 2 Galler M, Kronzon I, Slater J, Lighty G\v, Politzer F, Colvin S, et al. Long-term follow up after mitral valve reconstruction: incidence of postoperative left ventricular outflow obstruction. Circulation 1986; 74(suppll):99-103 3 Carpentier A, Deloche A, Dauptain J, Sayer R, Blondeau P, Piwnica A, et al. A new reconstructive operation for correction of mitral and tricuspid insufficiency. J Thorac Cardiovasc Surg 1971; 61:1-13 4 Rahko PS, BerkolfHA. Echocardiographic comparison of cardiac size and function before and after surgery for isolated mitral regurgitation: superiority of mitral valve repair vs mitral valve replacement. Acta Cardioll990; 45:189-94 5 Fundaro P, Salati M, CiaHfi A, Santoli C. PolytetraRuorethylene posterior annuloplasty for mitral regurgitation. Ann Thome Surg 1990; 5O:161Hi6 6 Cohn LH, Disesa Vj, Couper GS, Peigh PS, Kowalker \Y, Collins 11. Mitral valve repair for myxomatous degeneration and prolapse of the mitral valve. J Thorac Cardiovasc Surg 1989; 98:987-93

Successful Medical Therapy of Rhodococcus equl Pneumonia In a Patient with HIV Infectlon* }amu D. Cury, M.D.; lbul T. HarringtOfl, M.D. ; and Ian K. Hosetn, M.D.

A 34-year-old HIV-infected man was successfully treated with antimicrobial therapy alone for RhodococcuI equi pneumonia and hassurvived longer than six months. In the current literature, only two of seven HIV-infected patients so treated have survived as long as six months. Based on our experience and the available literature, it seems reasonable to treat HIV-infected patients with R equi pneumonia who do not require surgical intervention with prolonged intravenous therapy followed by long-term oral therapy with at least two effective antibiotics. The optimal choice and duration of antibiotic therapy need to be detenninecl. (Chm 1992; 102:1619-21)

IIUV = human immunode8ciency virus I

R hodococcw

equi is a cause of pneumonia in individuals with cell-mediated immunodeficiency including those

*From the University of Florida Health Science CenterlJacksonville, University Medical Center, Jacksonville . Reprint requem: Dr. Cury, Deparlment ofMedicine , 655l\bt Sixth Strut, Jacksonville, FL 32209 CHEST I 102 I 5 I NOVEMBER, 1992

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with HIV infection. There have been 16 cases of HIV-related pulmonary involvement with R equi described in the literature':" with a great deal of variability in the treatment of these individuals. Only two patients have had prolonged survival with antimicrobial therapy alone.··' Both of these patients received either prolonged or continuous therapy with two effective antibiotics. We present another patient who had resolution of his R equi pneumonia and prolonged survival with medical treatment alone . Although the number of reported cases is small, we believe that this case and those previously described have important implications for the treatment of this unusual infection. CASE REPORT

A 34-year-old man was admitted to the hospital with complaints of fever, cough, chest pain and weight loss. Seven weeks prior to admission he was noted to be infected with HIV and to have cavitary pneumonia caused by R equ/ at another institution. At that time , he was treated with intravenous vancomycin for four weeks and was discharged on a regimen of trimethoprim-sulfamethoxazole, one double-strength tablet twice daily. He did not take this medication and began to have the previously mentioned symptoms one week prior to admission. On admission the patient was noted to be thin and in no distress. His oral temperature was 38.3°C. Physical examination was within normal limits except for oropharyngeal lesions consistent with pseudomembranous candidiasis and rales in the left upper lung field. Laboratory studies revealed a mild normochromic normocytic anemia, with an absolute lymphocyte count of 454 cellsll.l-I with a CD4 + lymphocyte count of 50 cells/ul, the T4f1'8 ratio was 0.2. The initial radiograph is shown in Figure 1. Cultures of blood, bronchoalveolar lavage fluid and bone marrow aspirate all revealed R equ/. which is sensitive to chloramphenicol, erythromycin. gentamicin , tetracycl ine, trimethoprim-sulfamethoxazole and vancomycin. The isolate was resistant to ampicillin, cefazolin, clindamycin, oxacillin and penicillin. His echocardiogram was normal.

FIGURE 2. Chest radiograph 12 weeks after discharge showed an almost complete resolution of the left upper lobe pneumonia. Therapy with intravenous vancomycin (1 g each day), erythromycin (1 g every 6 h) and clindamicin (900 mg every 8 h) was begun. He had continuous fevers as high at 39.4"C for the first 20 days of therapy but then improved markedly and was without fever from hospital days 20 to 27. He then became febrile again on hospital days 28 to 32 and blood cultures again grew R equl with the same susceptibilities. He was afebrile on hospital days 33 and 34 and was discharged on a regimen of oral therapy with erythromycin (1 g every 6 h), clindamycin (300 mg every 6 h) and trimethoprim-sulfamethoxazole (one double-strength tablet daily); in addition, he was given 16 more days of intravenously administered vancomycin. Twelve weeks later he was asymptomatic and the chest radiograph (Fig 2) revealed nearly total resolution of the left upper lobe cavitary infiltrate. Therapy with erythromycin and trimethoprim-sulfamethoxazole was continued for life. DISCUSSION

FIGURE 1. Chest radiograph on admission showed a cavitary left upper lobe pneumonia.

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Bhodococcus equi (formerly Corynebacterium equi) is an aerobic Gram-positive weakly acid-fast bacillus that has been noted to cause cavitary pneumonia, empyema and brain abscesses in immunocompromised hosts. 15 Prior to this report, there have been 16 cases of HIV-related pulmonary R equi infections described in the literature. I · •• Pneumonia caused by R equi in the setting of HIV infection frequently cavitates, I frequently leads to empyema, has a relapsing and remitting course with intermittent bacteremia and can cause extrapulmonary abscesses. I Of the 16 reported cases, eight patients underwent surgical procedures for a variety of indicationss-" including the failure of antimicrobial therapy" One of the 16 reports does not give enough information to draw conclusions concerning therapy and outcome;" Seven patients received medical therapy alone; .... i ..13 of these, two patients survived longer than six months. r,1 Of the five patients who died, three patients·· 1I •11 were receiving one antibiotic, one patient

Successful MedIcalTherapyof Rhodococcus equl PneumonIa(CuI): Herrlngton, HotIeIn)

was noncompliant" and the therapy of one patient was not described. 10 Although it is hard to draw many conclusions on such a limited number of patients, the two patients who survived longer than six months'> and the currently described patient have similarities in treatment that separate them from the non-long-term survivors. All three long-term survivors received and had good response to prolonged treatment with two antibiotics to which the R equi isolate was proven to be sensitive. The patient described by Weingarten et all was treated with erythromycin, clindamycin and tetracycline, which resulted in improvement for six months. The patient described by Sirera et al2 was treated with intravenously administered ciprofloxacin and chloramphenicol for three weeks and was discharged on a regimen of the same oral drugs for suppression. These cases and the current case suggest that R equi pneumonia should be treated intravenously for three to six weeks with at least two antibiotics to which the R equi isolate has proven sensitivity. Also, since this organism is a central nervous system pathogen," the choice of antibiotics with good central nervous system penetration should be considered. Intravenous therapy should then be followed by two oral antibiotics for an indefinite period of time and perhaps for life. REFERENCES 1 Weingarten JS, Huang DY, Jackman JD. Bhodococcus equi pneumonia: an unusual early manifestation of the acquired immunodeficiency syndrome. Chest 1988; 94:195-96 2 Sirera G, Romey J, Clotet B, Velasco ~ Arnal J, Rius F, et ale Relapsing systemic infection due to Bhodococcus equi in a drug abuser seropositive for human immunodeficiency virus: review of infectious diseases 1991; 13:509-10 3 Samies JH, Hathaway BN, Echols RM, Veazey JM, Pilon VA. Lung abscess due to Corynebacterium equi: report of the first case in a patient with acquired immunode6ciency syndrome. Am J Med 1986; 80:685-88 4 Wang HH, Tollerud D, Danar D, HanfT ~ Gottesdiener K, Rosen S. Another Whipple-like disease in AIDS (Letter). N Engl J Med 1986; 314:1577-78 5 Sonnet J, Wauters G, Zech F, Gigi J. Opportunistic Bhodococcus equi infection in an African AIDS case (Letter). Acta Clin Belg 1987; 42:215-16 6 Bishoprie GA, d'Agay MF, Schlemmer B, Sarfati E, Brocheriou C. Pulmonary pseudotumor due to Corynebacterium equi in a patient with the acquired immunode6ciency syndrome. Thorax 1988; 43:486-87 7 Harvey RL, Sunstrum JC. Bhodococcus equi infection in patients with and without human immunode6ciency virus infection. Rev Infect Dis 1991; 13:139-45 8 Obana WG, Scannell KA, Jacobs R, Greco C, Rosenblum ML. A case of Bhodococcus equi brain abscess. Surg Neurol 1991; 35:321-24 9 Scannell KA, Pontoni EJ, Finkle HI, Rice M. Pulmonary malacoplakia and Bhodococcus equi infection in a patient with AIDS. Chest 1990; 97:1‫סס‬O-01 10 Haglund LA, Trotter JA, Slater LN, Harris SL, Rettig PJ. (Letter). N Engl J Moo 1989; 321:395 11 Sane DC, Durack DT. Infection with Bhodococcusequi in AIDS (Letter). N Engl J Moo 1986; 314:56-57 12 Kunke PJ. Serious infection in an AIDS patient due to Bhodococcus equi. Clin Microbiol Newsletter 1987; 9:20-21 13 Emmons ~ Reichwein B, Winslow DL. Bhodococcus equi infection in the patient with AIDS: Literature review and report of an unusual case. Rev Infect Dis 1991; 13:91-96

14 Fierer J, Wolf ~ Seed L, Gay T, Noonan K, Haghighi f! Nonpulmonary Bhodococcus equi infections with acquired immunodeficiency syndrome (AIDS). J Clin Patholl987; 40:556-58 15 Van Etta LL, Filice GA, Ferguson 8M, Gerding DN. Corynebacterium equi: a review of 12 cases of human infection. Rev Infect Dis 1983; 5:1012-18

Clearance of Theophylline by Hemodialysis in One Patient with Chronic Renal Failure* Dun-Bing Chang, M.D.; Sow-Hsor&g Kuo, M.D., F.C.C.~; lbn-Chyr Yang, M.D., F.C.C.~; Fu-Hsiung Shen, M.D.; and Kwen-Tay Luh, M.D., F.C.C.R

The clearance of theophylline by hemodialysis was determined in one patient who had polycystic kidney with chronic renal failure and bronchial asthma. The serum levels of theophyUine were determined by enzymatic immunoassay on two consecutive days, once on a dialysis day aDd again on a nondialysis day. Clearance of theophylline by hemodialysis was 119 mllmin, and the extraction efficiency was 0.56. The elimination half-life of theophylline shortened from 5.7 h to 1.6 b during bemodialysis. The dialysis rate constant (Kd) was 0.32/b, and 79 percent of the total body store ofthe drug was removed during a 4-b dialysis. Patients receiving theopbylline who are maintained on hemodialysis should be closely monitored for bronchospasm during and after the bemodialysis procedure. Measurement of serum concentrations of tbeopbyUine should be employed to facilitate increases in dosage during hemodialysis. (Chat 1992; 102:1621-23)

H

emodialysis has been regularly utilized therapeutically as a supportive treatment for end-stage renal disease; however, the effects of renal failure and hemodialysis on elimination of theophylline are not clear, and dosage guidelines for administering theophylline during hemodialysis are not well defined.' In nonsmoking subjects with normal hepatic and cardiac function, total body clearance of theophylline is highly variable, ranging from 30 to 120 ml/kglh.I.3 Only 7 to 13 percent of the parent compound is excreted unchanged in the urine,•.5 and renal theophylline clearance ranges from 3 to 9 ml/min/m" in persons with normal renal function.v" It is assumed that total body clearance and dosing requirements should be relatively unchanged in renal failure. I Since theophylline (molecular weight, 180) is only partially protein-bound (53 to 65 percent) and since the volume of distribution is small (0.3 to 0.7 Ukg), a signi6cant fraction of the drug should be cleared by hemodialysts.v'" Moreover, hemodialysis was suggested to be a treatment for patients with theophylline intoxicadon.v" Therefore, to clarify the effect of hemodialysis on elimination of theophylline, we administered aminophylline to one patient who had polycystic kidney with chronic renal failure and bronchial asthma *From the Departments of Internal Medicine and Clinical Pathology, National Taiwan University Hospital, and the Department of Internal Medicine, Tai-An Hospital, Taipei, Taiwan. Reprint requests: Dr. Chang, National Taiwan University Hospital, No.1 Chang-Te Street, Taipei, Taiwan, ROC 10016 CHEST I 102 I 5 I NOVEMBER. 1992

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