The validity of medical history, classic symptoms, and chest radiographs in predicting pulmonary tuberculosis: derivation of a pulmonary tuberculosis prediction model

STUDY OBJECTIVE

To improve the respiratory isolation policy for patients with suspected pulmonary tuberculosis (TB).

DESIGN

Prospective, descriptive, French multicenter study.

SETTING

Emergence of nosocomial outbreaks of TB.

PATIENTS

All consecutive patients admitted with suspicion of pulmonary TB.

MEASUREMENTS AND RESULTS

Medical history, social factors, symptoms, and chest radiograph (CXR) pattern (symptoms and CXR both scored as typical of pulmonary TB, compatible, negative, or atypical) were obtained on admission. Serial morning sputa were collected. Of the 211 patients, 47 (22.3%) had culture-proven pulmonary TB, including 31 (14.7%) with a positive smear. Mean age was 46.2 years; 52 patients were HIV positive (24.6%). The sensitivity of the respiratory isolation policy was 71.4%, specificity was 51.7%, negative predictive value (NPV) was 88.2%, and positive predictive value (PPV) was 26.3%. On univariate analysis, predictive factors of culture-proven pulmonary TB were CXR (p < 0.00001), symptoms (p = 0.0004), age (mean, 40.8 years for TB patients vs 47.5 years for non-TB patients; p = 0.04), absence of HIV infection (89.4% vs 71.3%; p = 0.01), immigrant status (72% vs 55%; p = 0.03), and bacillus Calmette-Guérin status (p = 0.025). On multivariate analysis, CXR pattern (p < 0.00001), HIV infection (p = 0.002), and symptoms (p = 0.009) remained independently predictive. Based on these data, a model was proposed using a receiver operating characteristics curve. In the derivation cohort, the sensitivity and NPV of the model in detecting smear-positive pulmonary TB would have been 100%. The specificity and PPV would have been 48.4% and 25%, respectively. The model performed less well when evaluated on two retrospective groups, but its sensitivity remained above that of the current respiratory isolation policy (91.1% and 82.4% for the retrospective groups vs 71.1% for the current policy).

CONCLUSIONS

Improved interpretation of clinical and radiologic data available on patient admission could improve adequacy of respiratory isolation. A prediction model is proposed.

Circuits with surface modifying additive alter the haemodynamic response to cardiopulmonary bypass

OBJECTIVE

Blood contact with synthetic surfaces during cardiopulmonary bypass (CPB), inevitably results in the activation of a variety of interrelated pathways of inflammation and coagulation that may contribute to postoperative complications in cardiac surgery patients. The objective of this trial was to evaluate clinical events and complement activation related to the use of a novel biomaterial, into which a surface modifying additive had been incorporated into the polymer used to prepare the bypass circuit.

METHODS

A prospective, double-blind trial was carried out with 34 patients randomized to surgery, with either a standard circuit or a circuit treated ('tip to tip') with the surface modifying additive. Variables recorded included perioperative haemodynamics, volume replacement, alpha-agonist and inotrope use. Terminal complement complex (SC5b-9) was measured using an ELISA.

RESULTS

Upon initiation of bypass, there was a decrease in mean arterial pressure (MAP) in the control group, not seen in the test group (P = 0.0005, ANOVA). There was a decrease in the total volume of replacement fluid given intraoperatively in the test group as compared with the control group (total plus prime; control 5.3 +/- 1.2 L, test 4.4 +/- 1.9 L, P = 0.03, Mann-Whitney test). There was a trend to decreased need for inotrope infusion in the test group after CPB (test 1/17, control 6/17, Fisher exact test; P = 0.085). No difference was seen in the generation of terminal complement complex between the groups either during or after CPB.

CONCLUSIONS

The decrease in blood pressure in the control group, upon the initiation of CPB, did not occur in patients undergoing CPB with the circuit prepared with the surface modifying additive. The decrease in blood pressure was likely associated with the increase in total administered fluids intraoperatively (approximately 1 l/patient) and perhaps the trend towards higher use of inotropes in the control patients as opposed to the test patients. These haemodynamic changes did not appear to be related to complement activation early in CPB.

Human immunodeficiency virus-related vasculitis. Clinical presentation of and therapeutic approach to eight cases

Vasculitides occurring during the course of human immunodeficiency virus (HIV) infection are heterogeneous in their clinical presentation, time of occurrence, histological findings and etiological factors. Some of them can be directly attributed to HIV infection and their treatment might require new therapeutic approaches, such as plasma exchanges, specific antiviral agents and/or vasodilators. We report 8 cases of vasculitis associated with HIV. Five of them met the classification criteria of polyarteritis nodosa and had symptoms compatible with microscopic polyangiitis. Etiological agents were not identified. Although hepatitis B virus, hepatitis C virus (HCV) and other viruses or opportunistic agents were detected in some patients, HCV was suspected of being the etiological factor in only 1 of them. Focusing on viral and immunological features, the possible mechanisms of vasculitis development in HIV+ patients are discussed. Long-term follow-up indicates a clear benefit of regimens including antiviral agents, vasodilators and plasma exchanges. No deterioration of AIDS status was observed with this treatment and no relapse was recorded.

The diaphragm in emphysema

Because of hyperinflation, the diaphragm of emphysematous patients operates at a disadvantageous position which affects its mechanical arrangement, modifies the configuration of its zone of apposition, increases its radius of curvature, and decreases its muscle fiber length below optimal configuration. The diaphragm in emphysema therefore displays a suboptimal configuration limiting its ability to function properly but shows no inherent structural insufficiency, unless its contractility is impaired by significant arterial blood gas anomalies or severe malnutrition. The demand imposed on the diaphragm in emphysema is increased by both hyperinflation and air-flow obstruction. With altered performance of the diaphragm and increased demand, force reserve is diminished and diaphragmatic fatigue may occur; this imbalance is targeted in some treatment modalities of emphysema such as pulmonary rehabilitation programs and lung volume reduction surgery.

Treatment of good-prognosis polyarteritis nodosa and Churg-Strauss syndrome: comparison of steroids and oral or pulse cyclophosphamide in 25 patients. French Cooperative Study Group for Vasculitides

Twenty-five patients with good-prognosis polyarteritis nodosa or Churg-Strauss syndrome entered a prospective, randomized, multicentre study comparing two treatments: either oral corticosteroids and oral cyclophosphamide (CY; 2 mg/kg/day) for 1 yr (group A), or oral corticosteroids and monthly i.v. CY pulses (0.6 g/m2) (group B) for 1 yr. The objective was to determine the optimal CY regimen. Judgement criteria were the efficacy of the treatment in controlling the disease and the development of side-effects. Among the 25 patients who could be analysed, complete recovery was achieved with the experimental treatment in 9/12 patients in group A and 10/13 patients in group B. Two patients in each group relapsed after the end of therapy and were well controlled by corticosteroids or other drugs. One failure occurred in each group. The mean follow-up was 60.8 +/- 14.5 months after the beginning of the treatment. Side-effects associated with the administration of CY and steroids were noted 27 times in group A vs 14 times in group B (not significant). The oldest patient in these series (group B) died of pneumonia. No superiority in terms of efficacy could be established between the two regimens; however, the number of patients included was too small to conclude definitively. Toxic side-effects were significantly more frequent in women (P < 0.02). The high number of adverse effects leads us to recommend pulse over oral CY and an overall lowering of the doses of immunosuppression.

[Osteoarthritis with rice bodies rich in calcium microcrystals. 4 cases with ultrastructural study]

Rice bodies are often found in inflammatory joint fluid specimens, especially from rheumatoid arthritis patients, but have rarely been reported in osteoarthritis. We found rice bodies in knee joint fluid specimens from four of 88 patients with osteoarthritis. There were three males and one female. Age ranged from 61 to 86 years. Three patients had slowly progressive knee osteoarthritis and one had rapidly destructive disease. Abundant, recurrent effusions occurred in all four patients despite one to five local corticosteroid injections per patient and radiation synovectomy in two patients. The joint fluid specimens contained 120 to 320 cells/mm3 and large numbers of rice bodies that stained with alizarin red S. Transmission electron microscopy studies showed that the rice bodies were composed of fibrin and contained numerous intra- and extra-cellular calcium crystals composed of apatite alone in two cases and of a combination of apatite and calcium pyrophosphate dihydrate in the two others. Collagen fibers and fragments of bone and cartilage were present in a few rice bodies. Phagocytic cells, type C synoviocytes, chondrocytes and a few inflammatory cells were also seen. These rice bodies composed mainly of fibrin and apatite may have played a role in the pathogenesis of the recurrent joint effusions in our patients.

[Research of Lyme's disease in facial paralysis. A French multicenter study]

OBJECTIVES

Apparent a frigore facial palsy could possibly mask manifestations of unrecognized Lyme's disease. Since commonly used corticosteroid treatment could be deleterious if Borrelia burgdorferi infection was indeed the cause, we conducted a prospective study to search for possible infections in cases of recently diagnosed a frigore facial palsy.

METHODS

For 3 years, 1990-1992, 49 French centres diagnosed a facial palsy in 346 patients (310 adults, 36 children under 15 years of age; mean age 38; range 16 months to 83 years). The patients were divided into three groups: a) facial palsy alone, b) zoster origin recognized due to outer ear eruption and c) cases with meningoradiculitis or joint signs or cases with facial diplegia. A questionnaire was used to evaluate exposure to risk of tick bits. A control group was established with 246 serum samples from subjects matched with the patients for age, geographical origin and exposure to risk of tick bits. Laboratory tests (indirect immunofluorescence and Western blot) were performed to search for anti-Borrelia burgdorferi antibodies in serum samples, and cerebral spinal fluid when possible, collected at presentation, on day 30 and on day 90.

RESULTS

Sixty percent of the patients were urban dwellers, 15% lived in rural and 25% in semi-rural areas. There were 294 patients with facial palsy alone and their serum results were compared with those of the matched controls. There was no significant difference in the positivity for Borrelia burgdorferi antibodies between these two groups.

CONCLUSION

These findings indicate that, unless there are clinical signs suggestive of borreliosis, it would not be necessary to test for Lyme's disease in patients with apparent a frigore facial palsy.

Cefepime pharmacokinetics in cystic fibrosis

STUDY OBJECTIVE

To determine the disposition of cefepime in patients with cystic fibrosis compared with healthy controls.

DESIGN

Open-label, single-dose study.

SETTING

Laboratoire de Pharmacocinétique Clinique, Université Laval, Québec, Canada.

PATIENTS AND SUBJECTS

Twelve patients with the confirmed diagnosis of cystic fibrosis (CF) and 12 healthy volunteers. One subject with CF withdrew for personal reasons; the data of another patient were excluded from the evaluation of renal values due to incomplete urine collection.

INTERVENTIONS

A single 2000-mg dose of cefepime was administered as a 30-minute intravenous infusion. Healthy subjects did not use any other drugs throughout the study. Those with CF refrained from taking prophylactic antibiotics prior to and during the study, but continued to use pancreatic enzymes, multivitamins, and beta-agonist and/or steroid inhalers. One patient continued insulin treatment.

MEASUREMENTS AND MAIN RESULTS

Cefepime's maximum concentration was approximately 150 micrograms/ml at the end of the infusion, half-life 2-2.5 hours, and urinary recovery 80% in both groups. No statistically significant difference was seen in any of the pharmacokinetic values between the groups, except for the mean residence time (2.03 +/- 0.26 vs 2.39 +/- 0.37 hrs; p < 0.02). Total clearance was 19% higher in patients with CF than in healthy volunteers (119.7 +/- 20.1 vs 103.5 +/- 19.8 ml/min), perhaps due to higher renal (95.1 +/- 12.4 vs 85.1 +/- 12.0 ml/min) and/or nonrenal (25.4 +/- 13.1 vs 18.4 +/- 12.0 ml/min) clearances in subjects with CF.

CONCLUSIONS

The disposition of cefepime is not significantly affected by CF, and dosage adjustment appears not to be necessary in these patients.

Fibrin ring granulomas in hepatitis A

Fibrin ring granuloma is characterized by a fibrinous ring surrounding a central fat vacuole. It has been found in the liver and bone marrow of patients with Q fever, and occasionally with visceral leishmaniasis, cytomegalovirus, Epstein-Barr virus, Staphylococcus epidermidis infections, Hodgkin's lymphoma, and hypersensitivity to allopurinol. We describe a case of serologically confirmed viral hepatitis A with this lesion in the liver biopsy. A false positive anti-hepatitis A virus IgM result has been excluded. This is, to our knowledge, the second reported case of type A hepatitis with hepatic fibrin ring granulomas. It confirms that hepatitis A should be included in the differential diagnosis of this lesion.

Altered disposition of fleroxacin in patients with cystic fibrosis

Thirteen patients with cystic fibrosis and 12 healthy control volunteers received a single oral 800 mg dose of fleroxacin and 800 mg every day for 5 days. Interstitial fluid penetration was studied by the suction-induced blister technique. Fleroxacin and its two major metabolites, N-demethyl and N-oxide, were analyzed in plasma and urine by HPLC. Single-dose absorption parameters (absorption rate constant, normalized peak plasma drug concentration, and time to reach peak concentration) and total urinary excretion indicated that fleroxacin was absorbed more slowly and more completely in patients with cystic fibrosis than in control subjects. Fleroxacin volume of distribution tended to be smaller in patients with cystic fibrosis and it reached statistical significance after a single dose when normalization for lean body mass was applied. When normalized for lean body mass, the formation clearance of N-demethyl fleroxacin and N-oxide fleroxacin was significantly greater in patients with cystic fibrosis than in control subjects (p less than 0.05). These data concur with those of others showing an induction of drug-metabolizing enzymes in cystic fibrosis. Renal clearances of fleroxacin and its metabolites were significantly increased in cystic fibrosis (p less than 0.05), and this seems to be explained by a decreased tubular reabsorption of these compounds. The differences seen in the pharmacokinetics of fleroxacin in cystic fibrosis support the theories of generalized induction of drug metabolism and of a defective renal tubular reabsorptive process of drugs in cystic fibrosis.

Relation to restenosis after percutaneous transluminal coronary angioplasty to vasomotion of the dilated coronary arterial segment

Among 868 patients with successful percutaneous transluminal coronary angioplasty (PTCA), 437 were restudied angiographically and had a provocative test with ergonovine during coronary angiography performed before and 6 months after the procedure. The relation between provoked coronary artery spasm and restenosis was studied and 4 groups of patients were analyzed. Those in group 1 (n = 63) had spasm before and after PTCA and their rate of restenosis was high (55%), especially when spasm after PTCA was observed on the dilated coronary segment (restenosis rate 58%). Patients in group 2 (n = 78) had spasm before PTCA but without abnormal vasoconstriction at 6 months and their incidence of restenosis was 19%. Sixty-one patients in group 3 had no spasm before PTCA but developed spasm at restudy. The rate of restenosis was high (38%) in this group, especially when the spasm after PTCA was located on the dilated segment (43%). In group 4 (n = 235), patients had no spasm before or after PTCA and the restenosis rate was 20%. Thus, the presence of coronary artery spasm on the dilated coronary segment, 6 months after a successful PTCA, is frequently accompanied (43% in group 3 and 58% in group 1) by restenosis.

Adult adrenoleukodystrophy: a sporadic case?

This is a report of a case of the adult cerebral form of X-linked ALD. The 27-year-old patient presented with psychiatric disturbances. NMR was performed and compared to CT scan to define cerebral demyelination. The level of hexacosanoate was found to be increased in the patient's serum. Biochemical analysis of the patient's mother's serum and cultured fibroblasts and of serum samples from 10 other members of the family who could have been carriers of this X-linked disease, produced negative results. Hence, it is most likely that this case has occurred sporadically. HLA determination revealed the DR2 antigen which is often associated with multiple sclerosis.

[Misleading symptoms of cerebral thrombophlebitis in pregnancy and the puerperium]

Four cases of cerebral thrombophlebitis, 3 of which occurred during post-partum and 1 during the first trimester of pregnancy, are reported. The symptoms were misleading, being predominantly psychiatric, with secondary appearance of an epileptic attack or motor deficit. The value of cerebral angiography is stressed in the literature.

[Cerebral cavernoma: a rare vascular malformation]

The authors have observed 7 cases of intracranial cavernous haemangioma. A review of the literature shows that the diagnosis is suggested by the occurrence of epileptic seizures, signs of expansive process or meningeal haemorrhage. Computerized tomography displays an area of hyperdensity enhanced by injections of a contrast medium. Surgical excision is mandatory. The post-operative mortality varies with the site of the malformation.

[Clinical and biochemical aspects of riboflavin deficiency in Haiti]

A study has been carried out in Haiti, involving 65 human subjects, mostly children, 39 of which had clinical symptoms of riboflavin deficiency, in order to correlate clinical symptoms and erythrocyte glutathion reductase activity. Angular stomatitis was associated with overt biochemical deficiency in 25% of the cases examined and in most cases seemed to be related to other nutritional or infectious disorders.