Effects of crystalloid and colloid fluids on extravascular lung water in hypoproteinemic dogs.

We compared the effect of crystalloid to colloid fluid infusion on extravascular lung water (EVLW) in hypoproteinemic dogs. Plasmapheresis was used to decrease plasma colloid osmotic pressure (COP) to less than 40% of its base-line level. Five animals were then infused with 0.9% sodium chloride (saline), five with 5% human serum albumin (albumin), and five with 6% hydroxyethyl starch (hetastarch) to increase the pulmonary arterial occlusive pressure by 10 Torr in comparison to the postplasmapheresis level for a 5-h study interval. On completion of the procedure, the lungs were harvested and EVLW measured by the blood-free gravimetric technique. Three to six times the volume of saline compared with albumin or hetastarch (P less than 0.001) was infused. In the saline animals, COP was decreased to 3.3 +/- 1.3 Torr, whereas COP was increased to 18.1 +/- 1.4 Torr in albumin animals (P less than 0.001) and 20.1 +/- 1.6 Torr in the hetastarch group (P less than 0.001). The saline-treated dogs developed gross signs of systemic edema. The EVLW was 8.1 +/- 0.9 ml/kg in saline animals compared with 5.3 +/- 2.1 ml/kg in the albumin (P less than 0.05) and 4.1 +/- 1.4 ml/kg in the hetastarch (P less than 0.01) groups. These data indicate that crystalloid fluid infusion during hypoproteinemia is associated with the development of both systemic and pulmonary edema.

Evaluating Multimembership Classifiers: A Methodology and Application to the MEDAS Diagnostic System.

Performance evaluation measures for multimembership classifiers are presented and applied in a retrospective study on the diagnostic performance of the MEDAS (Medical Emergency Decision Assistance System) system. Admission and discharge diagnoses for 122 patients with one or more of 26 distinct disorders in five major disorder categories were gathered. The average number of disorders per patient was 2 with 36 (29.5 percent) patients having 3 or more disorders simultaneously. The features (symptoms, signs, and laboratory data) available at admission were entered into a multimembership Bayesian pattern recognition algorithm which permits for diagnosis of multiple disorders. When the top five computer-ranked diagnoses were considered, all of the correct diagnoses for 86.1 percent of the patients were displayed by the fifth position. In 71.6 percent of these cases, no false diagnosis preceded any correct diagnosis. In ten cases a discharge diagnosis which was suggested by the available findings was omitted by the admitting physician. In six of these ten cases, the overlooked diagnoses appeared at the computer ranked list above all false diagnoses. Considering the urgency of diagnosis in the Emergency Department, the high uncertainty involved due to the limited availability of data, and the high frequency with which multiple disorders coexist, this limited study encourages our confidence in the MEDAS knowledge base and algorithm as a useful diagnostic support tool.

Mass ammonia inhalation.

The clinical, roentgenographic and laboratory findings, their relationship to each other and to the subsequent hospital course are reported for 14 victims of gaseous ammonia inhalation. Initial physical examination enabled differentiation of a mildly affected from a moderately affected group, but patients in both groups responded well to conservative medical management.

Cryptogenic fibrosing alveolitis.

Clinical, radiographic, and histologic data, together with pulmonary function features, in eleven patients with cryptogenic fibrosing alveolitis, are described in the following study. All these patients presented with a history of exertional dyspnea. Eight of the eleven had radiographic evidence of pleural involvement as manifested by blunting of one or both costophrenic angles. A restrictive defect was present in eight patients, all of whom had x-ray changes showing diffuse involvement. One of the patients presented showed marked improvement in all parameters including a repeat lung biopsy. Immunofluorescent studies of the lung biopsies from six patients revealed no evidence of immunologic damage. Based upon the histologic pattern of pulmonary reaction in the biopsies and the intervals between the onset of symptoms and the time of biopsy, a tenative scheme of temporal evolution of this disease is presented. Lung injury may lead either directly to diffuse interstitial pulmonary fibrosis (DIPF) or lungs may react to injury by an initial alveolar, mural or mixed pattern, all of which might ultimately progress to DIPF. An initial alveolar or mural pattern might change to a mixed pattern.