New criteria for the differentiation between transudates and exudates

AIMS: To investigate whether cholesterol and lactate dehydrogenase (LDH) measurements in fluids are more sensitive and specific markers for differentiating between exudates and transudates, as confirmed clinically, than the measurement of fluid total protein concentrations alone. PATIENTS/METHODS: Serum, pleural fluid, and ascitic fluid from 61 unselected patients were analysed retrospectively for LDH, cholesterol, and total protein. Clinical classification of transudate or exudate was reached independently by reviewing clinical details and laboratory data. RESULTS: Of 54 samples (40 pleural fluid and 14 ascitic fluid), 30 were classified clinically as exudates and 24 as transudates. Fluid LDH and fluid to serum protein ratio measurements were equally good at differentiating between exudates and transudates, with a sensitivity of 90%, a specificity of 79%, a positive predictive value (PPV) of 84%, and a negative predictive value (NPV) of 86%. A combination of these parameters improved sensitivity to 100% and NPV to 100%, but lowered the specificity to 71% and PPV to 81%. This combination achieved a higher efficiency than Light's criteria. CONCLUSION: Routine measurement of fluid LDH values and the calculation of fluid to serum total protein ratios will aid in differentiating exudates from transudates.     

Chlamydial pneumonitis induced in newborn guinea pigs.

One- to three-day-old guinea pigs were inoculated intranasally with the chlamydial agent of guinea pig inclusion conjunctivitis. Physical signs of infection included a marked increase in respiration rate on days 5 to 10 of infection and radiographic evidence of pneumonia on day 6. When animals were killed at various times after infection and lung tissue was examined by histopathology, evidence of pneumonia was found beginning on day 4 and lasting as long as day 12, with maximal pathological changes on days 6 to 8. The pneumonia was generally unilateral and consisted of an acute inflammatory component in the bronchioles with granulocytes in both the lumen and the wall of the bronchioles and an interstitial and intra-alveolar mononuclear infiltrate in the parenchyma of the lung. Chlamydial antigen was detected in the bronchial epithelial cells by immunoperoxidase staining, and the guinea pig inclusion conjunctivitis organism was isolated from lung tissue on days 6 to 9. No other significant bacteria were isolated from lung tissue or seen on gram stains of lung sections. Both immunoglobulin M and immunoglobulin G serum antibodies to the guinea pig inclusion conjunctivitis agent were detected as early as day 8 and reached peak levels on day 12. The infection was apparently self-limiting. This model presents the opportunity to investigate pathophysiological and immunological aspects of chlamydial respiratory infections in a neonatal animal.     

The behavioral response to novelty is altered in rats neonatally exposed to cocaine

It has recently been suggested that the effects of in utero cocaine exposure may result in subtle deficits related to a challenging environment, including exposure to novelty or stress. This study used a neonatal drug-exposure model to examine the behavioral response to a novel environment in rodents. Subjects were artificially reared (AR) from postnatal Days 4-10. There were four treatment groups; AR 40 mg/kg/day cocaine, AR 20 mg/kg/day cocaine, AR control group receiving no drug, and a normally reared control. In Experiment 1, subjects were tested for their preference of maternal home-cage or clean wood-chip odors in a T-maze on postnatal Day 15. Subjects from all treatment groups preferred the maternal odor. In Experiment 2, subjects were habituated to four familiar odors and tested with a novel odor in an open field (postnatal Days 16-21). Neonatal exposure to 20 mg/kg/day cocaine led to an overall increase in exploratory behavior during testing, whereas 40 mg/kg/day did not, supporting the hypothesis that developmental exposure to cocaine at some doses may alter the offspring's response to a changing environment.     

Effect of estradiol on chlamydial genital infection of female guinea pigs.

Female guinea pigs were treated daily with 1 mg of beta-estradiol-3-benzoate intramuscularly beginning 14 days before intravaginal inoculation with the chlamydial agent of guinea pig inclusion conjunctivitis and continuing during the course of the infection. Treatment with estradiol was found to markedly influence the course of genital infection with the chlamydial agent of guinea pig inclusion conjunctivitis, producing infections of greater intensity and longer duration than those in control animals. Moreover, pathogenesis was altered in that ascending infection was observed, resulting in endometritis, cystic salpingitis, and cystitis. Infection in the controls was limited to the cervix and vagina. Estradiol treatment increased the apparent number of infected cells in the cervix and vagina as detected by histopathology and immunofluorescent staining. Humoral and cell-mediated immune responses to the chlamydial agent of guinea pig inclusion conjunctivitis were comparable in estradiol-treated and untreated animals. These data indicate that hormonal manipulation may have profound effects on the course of chlamydial genital infections.     

Paradoxical excitement to sedative-hypnotics in mentally retarded clients

The relationships among "paradoxical" excitement to sedative--hypnotic medication, self-injurious behavior, and perinatal trauma were evaluated. Mentally retarded patients were classified as either paradoxical or normal responders to sedative-hypnotics. Paradoxical responders to these medications have a lower MA, a history of perinatal trauma, self-injurious behavior (SIB), and aggressive behavior when compared to normal responders. These findings confirmed and extended previous reports that a type of SIB may be indexed by paradoxical response to sedative-hypnotics. Results also suggested that perinatal trauma may be of etiological importance in the development of SIB. Because perinatal trauma or fetal distress results in excessive levels of B-endorphin, in utero, an impaired endogenous opiate system may be a critical factor maintaining a syndrome of SIB. Thus, these data may indicate psychopharmacological markers of SIB that may have both treatment and etiological significance.     

Perioperative transfusions associated with colorectal cancer surgery : Clinical judgment versus the hematocrit

We prospectively studied 123 patients with colorectal cancer in order to identify determinants of perioperative blood transfusions and unnecessary transfusions. Transfusions were considered unnecessary if the preoperative hematocrit reading exceeded 36% or the discharge hematocrit level exceeded 33%. Age, sex, admission hematocrit reading, operative procedure, specimen length, duration of surgery, estimated blood loss, tumor size, tumor differentiation, nodal status, Dukes' staging, and attending surgeon were evaluated in relation to perioperative blood transfusion using stepwise logistic regression. Fifty-one (41%) of the 123 patients in the study were transfused and 35 patients (28%) received at least 1 unnecessary unit of blood. Advanced age, low admission hematocrit reading, high estimated operative blood loss, prolonged procedures, and lengthy specimens were significantly related to the administration of blood. Excessive intraoperative transfusions and the practice of administering blood in pairs of units accounted for the unnecessary transfusions. This study indicates that factors that influence clinical judgment and thereby the decision to transfuse a patient are not accurate indicators of when blood should be given. Greater use of pre-transfusion hematocrit testing, especially in the operating room and before transfusing a second unit of blood, will dramatically reduce blood usage in elective colorectal cancer surgery.

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Resumen Hemos estudiado en forma prospectiva 123 pacientes con cáncer colorrectal con el objeto de identificar factores determinantes de transfusiones sanguíneas perioperatorias y de transfusiones innecesarias. Se consideró que las transfusiones eran innecesarias si el hematocrito preoperatorio excedía 36% o si el hematocrito de egreso excedía 33%. La edad y sexo, el hematocrito de admisión, el tipo de procedimiento operatorio, la longitud del especimen resecado, la duración de la operación, la magnitud estimada de la pérdida de sangre, el tamaño del tumor, el grado de la diferenciación del tumor, el estado de los ganglios, la clasificación Dukes del tumor y el cirujano, fueron valorados en relación con el volumen de transfusión perioperatoria utilizando el método de regresión logística escalonada. Cincuenta y uno (41%) de los 123 pacientes fueron transfundidos y 35 (28%) recibieron por lo menos una unidad de sangre innecesaria. La edad avanzada, un hematocrito bajo en el momento de la admisión, la escimación de una alta pérdida de sangre, los procedimientos prolongados y los especimenes de gran longitud aparecieron como factores significativamente relacionados con la administracion de sangre. Las transfusiones intraoperatorias excesivas y la práctica de administrar sangre en pares de unidades fueron responsables de las transfusiones innecesarias. Este estudio indica que los factores que influencian el juicio clínico, y por consiguiente la decisión de transfundir a un paciente, no son indicadores precisos de cuando se debe administrar sangre. Una mayor utilización del hematocrito pretransfusión, especialmente dentro de la sala de operaciones y antes de transfundir una segunda unidad de sangre, logrará disminuir en forma dramática el uso de sangre en cirugía electiva para cáncer colorrectal.

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Résumé Les auteurs se sont livrés à une étude prospective de 123 malades atteints de cancer colorectal dans le but d'identifier les facteurs qui ont été à l'origine de transfusions pré-, per-, et postopératoires et de transfusions inutiles. Les transfusions ont été considérées comme inutiles lorsque l'hématocrite préopératoire dépassait 36 pour cent ou qu'il excédait 33 pour cent au moment de la sortie de l'opéré. Pour apprécier la valeur de la transfusion périopératorie ont été pris en compte les divers facteurs suivants : l'âge, le sexe, le taux de l'hématocrite à l'admission, le type de l'intervention, la longueur du spécimen, la durée de l'opération, la quantité de sang perdu, la taille de la tumeur, le degré de différenciation du cancer, l'état des ganglions, le stade évolutif (classification de Dukes), la qualification du chirurgien. Cinquante et un des malades (41%) furent transfusés et 35 parmi eux (28%) reçurent inutilement au moins une unité de sang. L'ae avancé de l'opéré, le taux bas de l'hématocrite à l'admission, la perte importante de sang au cours de l'intervention, la longue durée de l'opération, l'importance de la pièce opératoire réséquée furent en rapport de manière significative avec l'administration de sang. Les transfusions inutiles furent le fait de l'administration excessive de sang au cours de l'opération ou de l'emploi d'unités doubles de sang. Cette étude indique que les facteurs cliniques ne constituent pas des éléments de valeur pour déterminer l'indication de la transfusion de sang. C'est le taux de l'hématocrite avant et au cours de l'intervention qu'il faut prendre en compte. L'observation de cette règle est appelée à réduire considérablement l'emploi du sang au cours de la chirurgie colorectale élective.

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Supported by the Frieda and George Zinberg Foundation and NCI-NIH grant 1 RO1-CA-35558-01.