- Email: [email protected]
The APACHE III Prognostic System
Finally, we would like to underscore that all patients with PPH should be tested for HIV infection. Testing can no longer be based on a history of high-risk behavior, because the prevalence of HIV infection is steadily increasing in nontraditional risk categories, such as heterosexuals. In Switzerland, for instance, in 1991 17.3 percent of all new AIDS cases occurred in heterosexual patients.' Rudolf Speich, M.D., Rnlf]enni, M.D., Milos Opravil, M.D., and Erich W Russi, M.D., F.C.C.P., University Hospital; and Marlene Pfab, M.D., 'IHemlispital, Zurich, Switzerland REFERENCES
1 Russi E. Opiatmissbrauch. Medizinische Komplikationen. Stuttgart, Germany: G. Fischer, 1986; 1-10 2 Arnett EN, Battle WE, Russo JY, Roberts WC. Intravenous injection of talc-containing drugs intended for oral use. Am J Med 1976; 60:711-18 3 Tomashefski JE, Hirsch CS. The pulmonary vascular lesions of intravenous drug abuse. Hum Pathol1980; 11:133-45 4 Kringsholm B, Christoffersen P. Lung and heart pathology in fatal drug addiction: a consecutive autopsy study. Forensic Sci lnt 1987; 34:39-51 5 AIDS Information [bulletin]. Zurich: Federal Office of Public Health, 1991; 46:719
Diagnosis of Mycobacterial Mediastinal Lymphadenopathy by Transbronchial Needle Aspiration 1b the Editor: 1 read with great interest the case report by Baron and Aranda, 1 which appeared in the December 1991 issue of Chest. In the past I was nearly daily fa<.-ed with intrathoracic lymphadenopathies and with the problem of how to proceed in establishing the correct diagnosis as soon as possible. Therefore, we developed some procedures and special needles• for pertracheal and perbronchial diagnostic puncture at the time ofbronchoscopic examination. We used this technique by gas insufHation in pneumomediastinography, • as well as for aspiration in the exammation of intrathoracic lymph nodes (eg, in the diagnosis and staging of malignant tumors [with proved metastases in 58.7 percent of 1,366 lung cancer patients]}' and in cases without evident radiographic enlargement. The effectiveness of our procedure was based on an anatomic study of the topography of selected nondiseased intrathoracic lymph nodes in relationship to the tracheobronchial tree, with estimation of their mean size. In cases of suspected sarcoidosis or tuberculosis, we used aspiration specimens for cytologic examination and preliminary rapid evaluation (the next day) by means of passive transfer of tuberculin hypersensitivity with the aid of intraperitoneal guinea pig injection, which is the first step in demonstrating virulent mycobacteria by animal inoculation. The third part of the specimen was cultured. In 1967 we reported positive results of culture and/or guinea pig inoculation using intrathoracic lymph node needle aspiration in 18 cases (24 percent of 75 examined patients). • In 1970 we published our success in establishing the presence of pathogenic Mycobacterium tuberculasis by culture and animal inoculation by needle aspiration of intrathoracic lymph nodes in three of 196 cases with the typical clinical picture of sarmidosis. •
Therefore, the article by Baron and Aranda is not the first report of mycobacterial intrathoracic lymphadenopathy diagnosed by means of transbronchial needle aspiration in a medical journal or monograph. Cyril Simelek, M.D., Phann.Mg., Sc.D., Department of Pneumology, University Hospital, Pilsen, Czechoslovakia REFERENCES
2 3
4 5
Baron KM, Aranda CP. Diagnosis of mediastinal mycobacterial lymphadenopathy by transbronchial needle aspiration. Chest 1991; 100:1723-24 Simerek C. Diagnostic pneumomediastinography. Dis Chest 1968; 53:24-30 Simerek C. Contribution of diagnostic needle aspiration in bronchoscopic investigation. In: Nahkhosteen JA, Maassen W. Bronchology: research, diagnostic, and therapeutic aspects. The Hague: Martinus Nijhoff, 1981; 311-12 Simerek c. L'importance des methodes bronchologiques dans le diagnostic des maladies du mediastin. Brooches 1967; 17:257-66 Simerek C. Nachweiss der Tuberkulosebazillen bei der Sarkoidose mittels der lierimpfung. Prax Pneumol1970; 24:494-97
To the Editor: During the time when we were writing our article, our search of the English-language medical literature failed to reveal other cases of intrathoracic mycobacterial lymphadenopathy diagnosed by transbronchial needle aspiration (TBNA) in the manner we described. The search was not extended to the non-English-language medical literature; hence, we were not aware of Dr Simerek's articles. Nevertheless, we appreciate Dr Simerek's pointing out that intrathoracic mycobacterial lymphadenopathy has been diagnosed by TBNA biopsy through a rigid bronchoscope. This further supports our remmmendation that when performing TBNA (which, in the majority of cases, is now being done through the fiberoptic bronchoscope), aspirates should be obtained for acid-fast smear and culture if a diagnosis of mycobacterial disease is being entertained. Intraperitoneal guinea pig inoculation ofaspirates, to our knowledge, is currently not being done routinely to diagnose tuberculosis. Conrado P. Aranda, M.D., and Kenneth M. Baron, M.D., Department of"kterans Affairs Medical Center; New York
The APACHE Ill Prognostic System To the Editor: We are writing con<.-erning the article by Knaus et al, 1 which appeared in the December 1991 issue of Chest. In that article the authors compare the overall correct classification rates, based on 2 X 2 classification tables with 0.50 cutpoint, for our Mortality Probability Model {MPM)' and the APACHE Ill system. The MPM system consists of distinct models at admission to the intensive care unit {ICU), at 24 h, and at 48 h. The authors correctly chose the 24h MPM, rather than the admission MPM, as the basis for their comparison with APACHE Ill, but their figure of79.1 percent total mrrect classification for the MPM is inmrrect. That number appears in a table in our article in which values are given li>r patients in the 1CU for 48 h or more. The accurate overall mrrect classification rate for the 24-h MPM, given in the text of the article, is 84.9 CHEST I 102 I 6 I DECEMBER, 1992
1919
pt•rcent, much closer to the APACHE Ill rate of 88.1 pen·ent than the value presented. This error in research was probably inadvertent, hut is Jwverthelt•ss misleading.
Danid Ten•s, M.D., Critical Care Division, Baystate Medical Center, Springfield, Massachusetts; and Stanll'Y l..i.'llu:shorc, Ph.D., Dt'1Hirlllwnt of Biostanvtics and Epidl'tniology, University of Massachusetts, Amherst REFERENCES
Knaus \VA, \Vagnt·r DP, Draper EA. Zimmerman JE, Bergner M, Bastos PC, et al. The APACHE Ill prognostic system: risk prediction ofhospitalmortality for critically ill hospitalized adults. Chest 1991; 100:1619-36 2 Lemeshow S, Teres D, Avnmin JS, GageR\\~ Refining intensive care unit oul<.~>me prediction hy using changing probabilities of mortality. Crit Care Mt•d 198R; 16:470-77 FIGURE 1. A T2-weighted image (relaxation time, 1,400 ms; echo time, 100 ms) shows an intermediate-intensity mass t'mtaining some low-intensity spots. Intensity of fat tissue is high, and fat can he easily distinguished from tumor.
To the Editor: We agn•e. We used a figure from Table 6 of the artide by Lemeshow et al, which was f<>r a restricted set of patients. The t"rrect overall classification from the study was 84.9 percent, achieved with the patients from a single hospital as t"mpared with a mrrect classification of 8R.1 percent \\ith APACHE Ill on a 40hospital data base. We emphasize, however, that because of the bias inherent in trying to t"mpare t"rrect classification rates across data files that have varying baseline outt.,me rates, we prefer receiver operating characteristie (ROC) areas. For the specific issue of predicting hospital death rates. ROC areas are even more useli.JI, since the mnventional thn•shold of a 0.50 risk of death used in the above t~>rrect classification caleulations is arbitrary. The APACHE Ill system achieved a 0.90 ROC area. \Ve also would like to take this opportunity to mrrect one error in our APACHE Ill article. The st•x ratio was reversed. The t1>rrect distribution of sex across !Cll admissions is 55.2 pt•rcent male and 44.8 pereent female. Sex has no relationship with outmme and is not used in any APACHE onlt1>me predictions.
William A. Knaus, M.D., ICU Research, Gt:orgt• \'
The intermediate signal intensity of the mass on the T1-weighted images was t"mpatihle with that of thymoma. On T2-weighted images, the intensity of the tumor was lower than that of fat, and the tumor t'mtained some areas of much lower intensity. According to Molina et al, 2 these findings probably mrrespond pathologically to septa and calcification. This is, to the best of our knowledge, the first report on the MR appearance of thymic squamous cell carcinoma in a case in which myasthenic symptoms led to detection of the tumor.
l'oshiaki Honda, M.D., Ichiro .\lurai, M.D., Mituyoshi Ayabe, M.D., Hiroshi Shoji, M.D., am/ Kotam Oi:;umi, M.D., Kunmw University School of Mediciru:, Kurome, japan Reprint requests: Dr. Honda, Kurome University School of Medicine, 67 Asahi-machi, Kurornc-shi, Fukuoka 830, japan REFERENCES
Magnetic Resonance Imaging of Thymic Squamous Cell Carcinoma Tc1 the Editor: Recently, magnetic resonance (MR) technolo~-,•y has provided specific signal intensities f<>r thymic squamous masses. Typical thymoma has been reported to show a signal intensity intermediate between the intensities of musde and fat on Tl-weighted images and an intensity almost equal to that offal on T2-weighted images . .., \Ve ent~mntered a 65-year-old man presenting with typical symptoms of myasthenia and the rare t'>mplication of thymic squamous cell carcinoma.' • Histologically, the tumor t~mtained many nests, calcified in part and surrounded by thick fibrous hands. Hassall's t1>1"]>Hsclelike figures, mon<>eytic keratinization, and intercellular bridges were also noted. An MR imaging study of the chest (Fig 1) was obtained with a 0.5-T supermnducting system (SMT 50, Simazu, Kyoto, Japan).
1920
Batra P. Hermann C, Mulder D. Mediastinal imaging in myasthenia gravis: mrrelation of chest radiology, CT, M R, and surgical findings. AJR 1986; 148:515-19 2 Molina PL, Siegel MJ, Glazer HS. Thymic masses on MR imaging. AJR 1990; 155:495-500 3 Dimario FJ, Lisak RP, Kostein MJ, Bnx>ks JJ. Myasthenia gravis and primary squamous cell carcinoma of the thymus: a case reJX>rt. Neurology 198R; 38:580-82 4 Shimosato Y, Kumeya T, Nagai K, Suemasu K. Squamous cell carcinoma of the thymus: an analysis of eight cases. Am J Surg Pathol1977; 1:109-21
Reexpansion Pulmonary Edema To the Editor: We read with great interest the article by Matsuura and t1>lleagues,1 which appeared in the December 1991 issue of Chest. In re1x>rting their experience with reexpansion pulmonary edema in a Communications to the Editor
1 Russi E. Opiatmissbrauch. Medizinische Komplikationen. Stuttgart, Germany: G. Fischer, 1986; 1-10 2 Arnett EN, Battle WE, Russo JY, Roberts WC. Intravenous injection of talc-containing drugs intended for oral use. Am J Med 1976; 60:711-18 3 Tomashefski JE, Hirsch CS. The pulmonary vascular lesions of intravenous drug abuse. Hum Pathol1980; 11:133-45 4 Kringsholm B, Christoffersen P. Lung and heart pathology in fatal drug addiction: a consecutive autopsy study. Forensic Sci lnt 1987; 34:39-51 5 AIDS Information [bulletin]. Zurich: Federal Office of Public Health, 1991; 46:719
Diagnosis of Mycobacterial Mediastinal Lymphadenopathy by Transbronchial Needle Aspiration 1b the Editor: 1 read with great interest the case report by Baron and Aranda, 1 which appeared in the December 1991 issue of Chest. In the past I was nearly daily fa<.-ed with intrathoracic lymphadenopathies and with the problem of how to proceed in establishing the correct diagnosis as soon as possible. Therefore, we developed some procedures and special needles• for pertracheal and perbronchial diagnostic puncture at the time ofbronchoscopic examination. We used this technique by gas insufHation in pneumomediastinography, • as well as for aspiration in the exammation of intrathoracic lymph nodes (eg, in the diagnosis and staging of malignant tumors [with proved metastases in 58.7 percent of 1,366 lung cancer patients]}' and in cases without evident radiographic enlargement. The effectiveness of our procedure was based on an anatomic study of the topography of selected nondiseased intrathoracic lymph nodes in relationship to the tracheobronchial tree, with estimation of their mean size. In cases of suspected sarcoidosis or tuberculosis, we used aspiration specimens for cytologic examination and preliminary rapid evaluation (the next day) by means of passive transfer of tuberculin hypersensitivity with the aid of intraperitoneal guinea pig injection, which is the first step in demonstrating virulent mycobacteria by animal inoculation. The third part of the specimen was cultured. In 1967 we reported positive results of culture and/or guinea pig inoculation using intrathoracic lymph node needle aspiration in 18 cases (24 percent of 75 examined patients). • In 1970 we published our success in establishing the presence of pathogenic Mycobacterium tuberculasis by culture and animal inoculation by needle aspiration of intrathoracic lymph nodes in three of 196 cases with the typical clinical picture of sarmidosis. •
Therefore, the article by Baron and Aranda is not the first report of mycobacterial intrathoracic lymphadenopathy diagnosed by means of transbronchial needle aspiration in a medical journal or monograph. Cyril Simelek, M.D., Phann.Mg., Sc.D., Department of Pneumology, University Hospital, Pilsen, Czechoslovakia REFERENCES
2 3
4 5
Baron KM, Aranda CP. Diagnosis of mediastinal mycobacterial lymphadenopathy by transbronchial needle aspiration. Chest 1991; 100:1723-24 Simerek C. Diagnostic pneumomediastinography. Dis Chest 1968; 53:24-30 Simerek C. Contribution of diagnostic needle aspiration in bronchoscopic investigation. In: Nahkhosteen JA, Maassen W. Bronchology: research, diagnostic, and therapeutic aspects. The Hague: Martinus Nijhoff, 1981; 311-12 Simerek c. L'importance des methodes bronchologiques dans le diagnostic des maladies du mediastin. Brooches 1967; 17:257-66 Simerek C. Nachweiss der Tuberkulosebazillen bei der Sarkoidose mittels der lierimpfung. Prax Pneumol1970; 24:494-97
To the Editor: During the time when we were writing our article, our search of the English-language medical literature failed to reveal other cases of intrathoracic mycobacterial lymphadenopathy diagnosed by transbronchial needle aspiration (TBNA) in the manner we described. The search was not extended to the non-English-language medical literature; hence, we were not aware of Dr Simerek's articles. Nevertheless, we appreciate Dr Simerek's pointing out that intrathoracic mycobacterial lymphadenopathy has been diagnosed by TBNA biopsy through a rigid bronchoscope. This further supports our remmmendation that when performing TBNA (which, in the majority of cases, is now being done through the fiberoptic bronchoscope), aspirates should be obtained for acid-fast smear and culture if a diagnosis of mycobacterial disease is being entertained. Intraperitoneal guinea pig inoculation ofaspirates, to our knowledge, is currently not being done routinely to diagnose tuberculosis. Conrado P. Aranda, M.D., and Kenneth M. Baron, M.D., Department of"kterans Affairs Medical Center; New York
The APACHE Ill Prognostic System To the Editor: We are writing con<.-erning the article by Knaus et al, 1 which appeared in the December 1991 issue of Chest. In that article the authors compare the overall correct classification rates, based on 2 X 2 classification tables with 0.50 cutpoint, for our Mortality Probability Model {MPM)' and the APACHE Ill system. The MPM system consists of distinct models at admission to the intensive care unit {ICU), at 24 h, and at 48 h. The authors correctly chose the 24h MPM, rather than the admission MPM, as the basis for their comparison with APACHE Ill, but their figure of79.1 percent total mrrect classification for the MPM is inmrrect. That number appears in a table in our article in which values are given li>r patients in the 1CU for 48 h or more. The accurate overall mrrect classification rate for the 24-h MPM, given in the text of the article, is 84.9 CHEST I 102 I 6 I DECEMBER, 1992
1919
pt•rcent, much closer to the APACHE Ill rate of 88.1 pen·ent than the value presented. This error in research was probably inadvertent, hut is Jwverthelt•ss misleading.
Danid Ten•s, M.D., Critical Care Division, Baystate Medical Center, Springfield, Massachusetts; and Stanll'Y l..i.'llu:shorc, Ph.D., Dt'1Hirlllwnt of Biostanvtics and Epidl'tniology, University of Massachusetts, Amherst REFERENCES
Knaus \VA, \Vagnt·r DP, Draper EA. Zimmerman JE, Bergner M, Bastos PC, et al. The APACHE Ill prognostic system: risk prediction ofhospitalmortality for critically ill hospitalized adults. Chest 1991; 100:1619-36 2 Lemeshow S, Teres D, Avnmin JS, GageR\\~ Refining intensive care unit oul<.~>me prediction hy using changing probabilities of mortality. Crit Care Mt•d 198R; 16:470-77 FIGURE 1. A T2-weighted image (relaxation time, 1,400 ms; echo time, 100 ms) shows an intermediate-intensity mass t'mtaining some low-intensity spots. Intensity of fat tissue is high, and fat can he easily distinguished from tumor.
To the Editor: We agn•e. We used a figure from Table 6 of the artide by Lemeshow et al, which was f<>r a restricted set of patients. The t"rrect overall classification from the study was 84.9 percent, achieved with the patients from a single hospital as t"mpared with a mrrect classification of 8R.1 percent \\ith APACHE Ill on a 40hospital data base. We emphasize, however, that because of the bias inherent in trying to t"mpare t"rrect classification rates across data files that have varying baseline outt.,me rates, we prefer receiver operating characteristie (ROC) areas. For the specific issue of predicting hospital death rates. ROC areas are even more useli.JI, since the mnventional thn•shold of a 0.50 risk of death used in the above t~>rrect classification caleulations is arbitrary. The APACHE Ill system achieved a 0.90 ROC area. \Ve also would like to take this opportunity to mrrect one error in our APACHE Ill article. The st•x ratio was reversed. The t1>rrect distribution of sex across !Cll admissions is 55.2 pt•rcent male and 44.8 pereent female. Sex has no relationship with outmme and is not used in any APACHE onlt1>me predictions.
William A. Knaus, M.D., ICU Research, Gt:orgt• \'
The intermediate signal intensity of the mass on the T1-weighted images was t"mpatihle with that of thymoma. On T2-weighted images, the intensity of the tumor was lower than that of fat, and the tumor t'mtained some areas of much lower intensity. According to Molina et al, 2 these findings probably mrrespond pathologically to septa and calcification. This is, to the best of our knowledge, the first report on the MR appearance of thymic squamous cell carcinoma in a case in which myasthenic symptoms led to detection of the tumor.
l'oshiaki Honda, M.D., Ichiro .\lurai, M.D., Mituyoshi Ayabe, M.D., Hiroshi Shoji, M.D., am/ Kotam Oi:;umi, M.D., Kunmw University School of Mediciru:, Kurome, japan Reprint requests: Dr. Honda, Kurome University School of Medicine, 67 Asahi-machi, Kurornc-shi, Fukuoka 830, japan REFERENCES
Magnetic Resonance Imaging of Thymic Squamous Cell Carcinoma Tc1 the Editor: Recently, magnetic resonance (MR) technolo~-,•y has provided specific signal intensities f<>r thymic squamous masses. Typical thymoma has been reported to show a signal intensity intermediate between the intensities of musde and fat on Tl-weighted images and an intensity almost equal to that offal on T2-weighted images . .., \Ve ent~mntered a 65-year-old man presenting with typical symptoms of myasthenia and the rare t'>mplication of thymic squamous cell carcinoma.' • Histologically, the tumor t~mtained many nests, calcified in part and surrounded by thick fibrous hands. Hassall's t1>1"]>Hsclelike figures, mon<>eytic keratinization, and intercellular bridges were also noted. An MR imaging study of the chest (Fig 1) was obtained with a 0.5-T supermnducting system (SMT 50, Simazu, Kyoto, Japan).
1920
Batra P. Hermann C, Mulder D. Mediastinal imaging in myasthenia gravis: mrrelation of chest radiology, CT, M R, and surgical findings. AJR 1986; 148:515-19 2 Molina PL, Siegel MJ, Glazer HS. Thymic masses on MR imaging. AJR 1990; 155:495-500 3 Dimario FJ, Lisak RP, Kostein MJ, Bnx>ks JJ. Myasthenia gravis and primary squamous cell carcinoma of the thymus: a case reJX>rt. Neurology 198R; 38:580-82 4 Shimosato Y, Kumeya T, Nagai K, Suemasu K. Squamous cell carcinoma of the thymus: an analysis of eight cases. Am J Surg Pathol1977; 1:109-21
Reexpansion Pulmonary Edema To the Editor: We read with great interest the article by Matsuura and t1>lleagues,1 which appeared in the December 1991 issue of Chest. In re1x>rting their experience with reexpansion pulmonary edema in a Communications to the Editor