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Biomedical subjects

D Mathieu

Publications and source records attributed to D Mathieu.

At least 55 records · Page 3Linked to original sources
PubMed1993

Diagnosis of pneumonia in mechanically ventilated patients. Repeatability of the protected specimen brush.

The repeatability (i.e., the variation in repeated measurements of the same quantity) of the protected specimen brush (PSB) with quantitative cultures was assessed in 22 consecutive mechanically ventilated (MV) patients with suspected nosocomial pneumonia. Five PSB samples were collected in the same lung area during the same bronchoscopic procedure and processed for bacteriologic identification and quantitative culture. A laboratory control was also performed in order to assess the in vitro repeatability of the quantitative culture technique. The five PSB always recovered the same microorganisms, indicating a 100% qualitative repeatability for the PSB. Conversely, the quantitative repeatability was somewhat lower since in 59% of the patients the quantitative results varied by more than one log10, which is the minimal precision affordable with quantitative cultures. The distinction between presence or absence of infection based on the 10(3) cfu/ml recommended diagnostic threshold was, however, only moderately affected by the variability of the quantitative results since only three of 22 patients (13.6%) displayed results spread out on each side of the 10(3) cfu/ml break point. Intrasubject variability of quantitative results was not explained by problems with the quantitative culture technique, which proved excellent repeatability in the laboratory. This study indicated that, although the PSB technique with quantitative cultures displays an acceptable level of repeatability, caution is advisable when interpreting PSB results in critically ill patients with suspected pneumonia, especially if one refers to the 10(3) cfu/ml recommended diagnostic threshold and if a decision to treat or to abstain from treating is to be made.

Bacteria↗
PubMed1993

Diagnostic efficiency of endotracheal aspirates with quantitative bacterial cultures in intubated patients with suspected pneumonia. Comparison with the protected specimen brush.

The objectives of the study were to determine the agreement between the protected specimen brush technique (PSB) with quantitative cultures and endotracheal aspirates (EA) with quantitative cultures when using increasing interpretative cutoff points and to investigate the respective operating characteristics for the diagnosis of pneumonia of PSB and EA when using quantitative cultures. Consecutive sampling of respiratory secretions using these two techniques was conducted in the respiratory intensive care units in 52 mechanically ventilated patients with clinical and radiologic suspicion of pneumonia. Quantitative bacterial cultures of PSB and EA samples were obtained. The 10(6) cfu/ml cutoff point was the most accurate diagnostic threshold for the EA technique. When using this threshold, there was a high level of agreement (84.6%) between PSB and EA results. Among the few discrepancies, the EA result was always indicative of pneumonia, whereas the PSB result was nonindicative, thus permitting us to classify correctly five patients in whom pneumonia would have been erroneously excluded on the basis of the sole result of PSB. Conversely, there was no case where the PSB result was indicative of pneumonia when the EA result (at the 10(6) cfu/ml level) was not. The operating characteristics of the PSB technique for the diagnosis of pneumonia were in accordance with previously published studies. The operating characteristics of the EA technique (when taking the 10(6) cfu/ml of respiratory secretions as the interpretative cutoff point) compared favorably with those of the PSB technique. Diagnostic accuracy rates were similar. The specificity of EA was somewhat lower (83 versus 96%), but the sensitivity was higher (82 versus 64%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Protected specimen brush in the assessment of ventilator-associated pneumonia. Selection of a certain lung segment for bronchoscopic sampling is unnecessary.

The protected specimen brush (PSB) with quantitative cultures is one of the most reliable techniques for assessing pneumonia in mechanically ventilated (MV) patients. The need to select a certain lung segment for bronchoscopic sampling is still debated. We investigated whether the results of PSB specimens collected within an area radiographically involved with pneumonia (inv-PSB) differed from the results of PSB specimens collected within a lung area without radiographic abnormalities (non-inv-PSB) in 39 MV patients with suspected pneumonia. The comparison of bacterial titers of inv-PSB and non-inv-PSB cultures did not disclose significant differences. Agreement regarding the diagnosis of pneumonia according to recommended diagnostic threshold was observed in 34 of 39 patients (87.1 percent). These results which are in accordance with the pathophysiology of ventilator-associated pneumonia and histologic studies do not support the need to select a certain lung segment for bronchoscopic sampling in most MV patients with suspected pneumonia.

Acinetobacter Infections↗
PubMed1993

Detection of multiple myeloma involving the spine: efficacy of fat-suppression and contrast-enhanced MR imaging.

OBJECTIVE: To determine the efficacy of fat-suppressed sequences and contrast-enhanced MR imaging for the detection of focal spinal lesions caused by multiple myeloma, we obtained MR images in 32 patients with newly diagnosed myeloma who had back pain. SUBJECTS AND METHODS: All patients had biopsy-proved myeloma and had MR imaging at the painful level of the spine. Spin-echo T1-weighted, T2-weighted, and short TI inversion-recovery (STIR) images; dynamic ultrafast low-angle shot (turbo-FLASH) images after IV injection of a bolus of paramagnetic contrast material; and contrast-enhanced T1-weighted images were obtained. We qualitatively compared the signal intensities and contrast enhancement of focal lesions with those of the surrounding vertebral bodies. RESULTS: Multiple lesions were detected in all but two of the 32 patients. On T2-weighted and STIR images, all lesions had homogeneously high signal intensity. On T1-weighted images, the lesions were visible as hypointense areas compared with surrounding bone in all except four patients, in whom the lesions were isointense or hyperintense. All tumor nodules enhanced on turbo-FLASH images obtained in the arterial phase. No additional lesions were seen on STIR or contrast-enhanced images. MR findings resulted in a change in the staging of the disease in one patient and led to prompt treatment in five patients with epidural involvement. CONCLUSION: MR imaging appears to be helpful in detecting spinal involvement in patients with multiple myeloma. The diagnosis of spinal lesions is best achieved by using either fat-suppressed or T2-weighted images. Although myeloma lesions enhanced in all patients, contrast material appears to be of no value for the detection of additional lesions.

Contrast Media↗
PubMed1993

MR appearance of multiple myeloma of the spine before and after treatment.

OBJECTIVE: The aim of this study was to describe the changes in the MR appearance of painful lesions of the spine before and after treatment in 18 patients with multiple myeloma and to correlate these changes with the clinical response to treatment. SUBJECTS AND METHODS: Eighteen patients with multiple myeloma and tumor nodules in the spine had MR imaging of the same site in the spine before and after treatment. Unenhanced T1- and T2-weighted spin-echo images, dynamic ultrafast low-angle shot (turbo-FLASH) images before and after IV bolus injection of paramagnetic contrast material, and contrast-enhanced T1-weighted spin-echo images were obtained. Characteristic signal and contrast enhancement before and after treatment were compared and were correlated with clinical data and the results of immunochemical and pathologic tests. RESULTS: Changes in signal intensity and enhancement of the lesions occurred after treatment in 14 of 18 patients. The characteristics of the lesions after treatment had three patterns: (1) rim enhancement or no enhancement of the lesions, (2) early enhancing lesions associated with other nonenhancing lesions or lesions with rim enhancement, and (3) no change from the enhancement pattern seen before treatment. In 13 of 18 patients, these patterns correlated well with the response to treatment. A discrepancy was observed in five patients. CONCLUSION: The MR appearance of spinal myeloma is different before and after treatment. MR images, particularly contrast-enhanced images, may be helpful in monitoring the response to treatment of focal bone lesions of myeloma.

Combined Modality Therapy↗
PubMed1993

Atrazine in plasma and tissue following atrazine-aminotriazole-ethylene glycol-formaldehyde poisoning.

A high performance liquid chromatography method has been used to study the plasma kinetics of atrazine in a human fatality after ingestion of a herbicide mix containing atrazine, aminotriazole, ethylene glycol and formaldehyde. A hemodialysis was performed in an effort to eliminate these toxic substances. The mean atrazine clearance over 4 h was 250 mL/min and the dialysance of atrazine was calculated as 76%. On autopsy, the kidney showed the highest concentration of atrazine (97.62 micrograms/g-1 wet tissue) with lesser concentrations in the lung, small intestine and liver, and the lowest concentration in the heart.

Adult↗
PubMed1993

Pedicle musculocutaneous flap transplantation: prediction of final outcome by transcutaneous oxygen measurements in hyperbaric oxygen.

In pedicle musculocutaneous flaps, a local circulatory insufficiency with a total or subtotal ischemia may occur and jeopardize the result of the reconstructive surgery. Transcutaneous oxygen pressure (PtcO2) monitoring has been shown to reflect tissue perfusion and has been advocated to predict the final outcome of ischemic flaps. Unfortunately, under normal atmospheric conditions, this test is not sufficiently discriminative. We evaluate the effect of hyperbaric oxygen conditions on the efficiency of this test. Fifteen patients with pedicle musculocutaneous flap were evaluated by clinical examination and transcutaneous oxygen tension measurements. The final outcome was healing in 7 and failure in 8. In order to determine the predictive value of transcutaneous oxygen tension, measurements were done immediately after the surgical procedure. In ambient air, neither the absolute value of transcutaneous oxygen tension (2.6 +/- 3.6 versus 11.7 +/- 12.6 torr; N.S.) nor the difference or the ratio between the transcutaneous oxygen tension of the flap and the subclavicular reference shows any significant difference according to the outcome (failure or success). The same is true in normobaric oxygen. In hyperbaric oxygen, however, there is a significant difference in transcutaneous oxygen tension between the two groups (12 +/- 12 versus 378 +/- 385 torr; p < 0.01). A transcutaneous oxygen tension higher than 50 torr in hyperbaric oxygen (2.5 atm abs) is the best cutoff value to discriminate success from failure.

Adult↗
PubMed1992

[Liver transplantation associated with combined adjuvant treatment in hepatocellular carcinoma. Feasibility and preliminary results].

Combined adjuvant therapy was prospectively assessed in 7 patients receiving orthotopic liver transplantation for hepatocellular carcinoma complicating cirrhosis. The protocol included hepatic arterial chemotherapy while waiting for transplant, immediate preoperative liver irradiation, and early postoperative chemotherapy. There were no postoperative deaths, and morbidity included mainly hematologic toxicity of chemotherapy. Two patients died of tumor recurrence 6 and 14 months after transplant. The remaining 5 patients are alive and free of disease with a follow-up of 7 to 26 months. These results show the feasibility of aggressive adjuvant therapy in patients transplanted for hepatocellular carcinoma and suggest a possible effect of such a protocol on the prevention of tumor recurrence.

Adult↗
PubMed1992

[Clinical symptomatology and radiological aspects of primary cancers of the liver].

Hepatocellular carcinoma is a malignant tumor derived from hepatocytes. It is the most frequent of primary liver cancers. In 90% of the cases, it occurs in a cirrhotic liver and is now more and more detected by ultrasonographic screening of cirrhotic patients. Hepatocellular carcinoma can also be diagnosed at a more advanced stage, when complications, such as ascites, jaundice or digestive hemorrhage, occur. CT scan and magnetic resonance imaging are useful to confirm ultrasonographic findings, but angiography with infusion of Lipiodol in hepatic artery followed by CT scan remains the most sensitive method for diagnosis. Intrahepatic cholangiocarcinoma is derived from intrahepatic bile duct cells and does not occur in a preexisting cirrhotic liver. Diagnosis is usually late. Clinical features are those of hepatic malignancy with jaundice and abdominal pain. Morphological examination of the liver shows an intrahepatic tumor, sometimes associated with a dilatation of the surrounding bile ducts. Other primary malignancies are very rare. Fibrolamellar carcinoma presents as an abdominal mass occurring in a young adult with a non cirrhotic liver. Prognosis is better than that of hepatocellular carcinoma. Cystadenocarcinoma is a cystic tumor of bile ducts that can develop in a preexisting cystadenoma. Angiosarcoma is a highly malignant tumor derived from sinusoidal endothelial cells. Exposure to various carcinogens is found in 30% of the cases. Epithelioid hemangio-endothelioma differs from angiosarcoma by its occurrence in young adults and a more favorable prognosis.

Angiography↗
PubMed1992

Massive arsenic poisoning--effect of hemodialysis and dimercaprol on arsenic kinetics.

In massive arsenic poisoning, the use of hemodialysis and dimercaprol (BAL) therapy is still controversial. Hemodialysis is thought of value only for supportive care. BAL therapy has been criticized because of its delayed action, its own toxicity and its possible influence on arsenic clearance during hemodialysis. We studied arsenic kinetics during an acute suicidal intoxication (10 g of sodium arsenate). Treatment included gastric lavage, oral charcoal and supportive measures. Hemodialysis was performed immediately and repeated the next day. BAL therapy was prescribed only on the second day. Cardiovascular collapse, anuria and hepatic disturbance recovered in a few days and the patient could be discharged on the 15th day. Instantaneous serum arsenic hemodialysis clearance was 85 +/- 75 ml/min without previous BAL injection and 87.5 +/- 75 ml/min with a previous 250 mg BAL injection (difference not significant) indicating that BAL did not impede arsenic dialysis. The calculated total hemodialysis clearance of arsenic was higher than mean serum hemodialysis clearance indicating that erythrocyte bound arsenic is also eliminated during dialysis. We propose to consider early hemodialysis as an elimination measure in massive arsenic poisoning and to choose BAL as a chelator when dialysis is required.

Adult↗
PubMed1992

Value of CT and sonography in the conservative management of acute splenoportal and superior mesenteric venous thrombosis.

Acute splenoportal and superior mesenteric venous thrombosis were diagnosed on sonography and computed tomography (CT) in six patients. Sonography demonstrated the presence of echoic material filling the involved vessels in all patients. Precontrast CT scans demonstrated an increased, intra luminal density of the clots in four patients with splenoportal thrombosis. However, in two cases of superior mesenteric venous thrombosis, no hyperdensity was observed within the lumens. Nevertheless, the clots were always visualized as low-density regions in the vessel lumens after bolus injection. Intravenous anticoagulant therapy was started immediately after the diagnosis. All patients were evaluated twice a week with sonography and/or CT until recanalization occurred. The patency of the previously involved vessels was assessed from 6 days to 4 weeks after the acute episode (average time of recanalization: 17 days) without development of collateral pathways. It is concluded that, in the absence of clinical signs of a life-threatening process, a conservative management of acute splanchnic thrombosis can be successfully achieved by (1) early diagnosis, (2) efficacious intravenous anticoagulant therapy, (3) careful imaging follow-up of these patients by sonography and/or CT during the acute phase and, finally, (4) by an extensive search for a hypercoagulable state.

Acenocoumarol↗
PubMed1992

Fast magnetic resonance imaging in the evaluation of tumoral obstructions of the inferior vena cava.

A prospective study was conducted on 9 patients with suspected obstruction of the inferior vena cava on ultrasonography, dynamic computerized tomography and/or inferior venacavography during the course of a retroperitonal tumor to assess the value of magnetic resonance imaging with gradient echo sequences. The findings on gradient echo magnetic resonance imaging were compared with the other imaging modalities and surgical or necropsy results. Our results suggest that gradient echo magnetic resonance imaging is the most appropriate imaging modality to diagnose and delineate the extent of inferior vena caval obstruction.

Adult↗
PubMed1992

[Relapse prevention in liver transplant patients treated for liver involvement due to hepatitis B virus].

Controversy surrounds the indication of liver transplantation in patients with hepatitis B virus infection. The major problem is the very high risk of infection of the graft. Some investigators have suggested that the presence of HBsAg is a contraindication to liver transplantation. Between February 1975 and December 1990, 178 HBs positive patients were transplanted at Paul Brousse Hospital in Professor H. Bismuth's Department, 137 for post hepatitis cirrhosis and 41 for fulminant hepatitis. Since April 1984 we have decided long term immunoprophylactic therapy for all patients with HBs infection. But only from August 1987 our supply of purified anti HBs immunoglobulin has been adequate to treat all our patients according to the following protocol: 10.000 IU during the peroperative phase, 10.000 IU immediately after intervention, 10.000 IU every day for the first 6 days, 10.000 IU when the anti HBs levels were under 150 IU/l. One hundred thirty-nine patients were treated by this method. 110 cleared HBs antigen from their sera and their liver were biologically and histologically free of B virus infection. 29 patients showed reappearance of HBs antigen in their sera and nearly all of them developed objective, histologically confirmed, graft lesions. These lesions are those of classical infection: acute hepatitis, active chronic hepatitis and cirrhosis. So 79% of patients were successfully treated with a follow up of 45 months to 6 months. We also studied the prognostic factors under treatment. The study shows: in the case of fulminant hepatitis, 93% success versus 77% in post hepatitis cirrhosis; in the case of Delta superinfection, 94% success versus 66% with pure B infection; in the absence of HBVDNA in the patient's sera before transplantation, 92% success versus 20% in the presence of HBVDNA. For a better understanding of the overall results, the two following parameters have to be considered: some patients relapsed after stopping their treatment, some other patients, despite repositivation of HBs antigen in their sera showed a paradoxal good evolution. These considerations enable us to obtain HBVDNA positive patients: 10% success, HBVDNA negative patients: Fulminant hepatitis: 100% success B Delta post hepatitis cirrhosis: 100% success B post hepatitis cirrhosis: 92% success.

Hepatitis B↗
PubMed1992

Asymptomatic renal-vein thrombosis in adult nephrotic syndrome ultrasonography and urinary fibrin-fibrinogen products: a prospective study.

OBJECTIVES: The diagnosis of renal vein thrombosis (RVT), a frequent complication of adult nephrotic syndrome (NS), is generally made by means of invasive methods, i.e. renal venography, venous time of renal arteriography and, more recently, computed tomography (CT). We undertook a prospective study to evaluate the use of Doppler ultrasonography (DUS) and urinary fibrin-fibrinogen degradation products (FDPU) for the diagnosis of asymptomatic RVT. METHODS: Thirty-one adult NS with non proliferative glomerulonephritis were studied. Reference procedures [(selective renal arteriography (n = 18) and renal vein CT (n = 13)] were performed blindly within a few days (48 hours in 17 patients) of renal vein DUS (search for a lack of venous flow) and measurement of FDPU (5 micrograms/min) (in 24 patients). RESULTS: DUS was not interpretable in one patient and positive in nine. Of these 9 patients, RVT was detected by reference methods in only two (sensitivity: 1, specificity: 0.75; positive predictive value: 0.22; negative predictive value: 1). Increased FDPU was observed in 4 patients, 2 of whom had an RVT (sensitivity: 1, specificity: 0.9; positive predictive value: 0.5; negative predictive value: 1). CONCLUSION: We conclude that DUS and FDPU are helpful for screening of RVT in asymptomatic NS patients; their negativity allow further radiological investigations to be avoided while positive results must be confirmed by reference methods.

Adolescent↗
PubMed1992

[Role of hyperbaric oxygenation in the treatment of acute anaerobic infections].

Hyperbaric oxygenation (HBO), as an adjuvant treatment in necrotizing soft tissues infections and in gas gangrene is reviewed, including its specific effects, experimental studies and clinical reports. With a global therapeutic management, considered as an emergency state, including surgery, antibiotic regimens and HBO, we can obtained 50% mortality and morbidity decrease with a more conservative surgery. Finally, favorable outcome is associated with early therapeutics and localization of the initial necrotizing infection.

Acute Disease↗
PubMed1992

Failure of percutaneous drainage of pancreatic abscesses complicating severe acute pancreatitis.

From 1981 to 1990, 14 of 70 patients hospitalized at our institution for severe acute pancreatitis were selected to undergo percutaneous drainage of pancreatic abscess, under computed tomographic (CT) scan guidance. Pancreatic abscess was defined, on contrast-enhanced CT scan, as an infected fluid collection without pancreatic necrosis. There were nine men and five women, ranging in age from 28 to 46 years. The main cause of pancreatitis was alcohol abuse (eight patients). Other causes were gallstones (two patients), hyperlipidemia (two patients), postoperative (one patient) and one unknown. Ranson criteria were available in ten patients and ranged from three to six. Percutaneous drainage was performed as the primary treatment in 13 patients and for removal of a residual collection postoperatively in one patient. In two critically ill patients, percutaneous drainage was performed as a temporizing measure. In 12 patients with well-limited hypodense collections, percutaneous drainage was expected to result in the definitive cure of the abscess. Pigtail drains (No. 14F), were inserted using local anesthesia and CT scan guidance. Two patients had two drains and 12 patients had only one drain. Two patients were definitively cured by percutaneous drainage and all other patients were operated upon for removal of infected necrosis. In this study, the lack of accuracy of contrast-enhanced CT scan in the diagnosis of peripancreatic necrosis is highlighted and that percutaneous drainage has a better efficiency in the treatment of residual collections postoperatively than as a primary treatment of infected fluid collections is illustrated.

Abscess↗