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Biomedical subjects

G Nitenberg

Publications and source records attributed to G Nitenberg.

At least 37 records · Page 2Linked to original sources
PubMed2000

Accuracy of totally implanted ports, tunnelled, single- and multiple-lumen central venous catheters for measurement of central venous pressure.

OBJECTIVE: To verify the accuracy of totally implanted ports, tunnelled central venous catheters (CVC), widely used in cancer patients, and multi-lumen catheters, used in intensive care units (ICUs), in measuring central venous pressure (CVP), using right atrial pressure (RAP) measured in a Swan-Ganz catheter as the reference standard. DESIGN: A prospective study, over a 10-month period. SETTING: A medical-surgical ICU in a comprehensive cancer centre. PATIENTS AND PARTICIPANTS: Patients who had both (1) a Swan-Ganz catheter and (2) either a tunnelled catheter, a single or a multi-lumen catheter, or a totally implanted port. INTERVENTIONS: RAP and CVP were measured simultaneously in each patient. MEASUREMENTS AND RESULTS: Fifty-six pairs of RAP-CVP measurements were performed in 35 patients: 6 tunnelled catheters, 6 non-tunnelled single-lumen catheters, 26 multiple-lumen catheters and 18 totally implanted ports were studied. RAP measured in the Swan-Ganz catheter and CVP measured in the CVC were strongly correlated (r = 0.94, p < 0.01), whatever the type of catheter studied. The mean difference between RAP and CVP was -0.39 +/- 1.73 (SD) mmHg. In 51 cases (91%), the difference was within the limits of agreement (-3.78 to 3.00 mmHg, Bland and Altman method). For the five cases with a difference of 4 mmHg (three totally implanted ports, one double- and one triple-lumen catheter), CVP was greater than RAP. CONCLUSIONS: CVP can be accurately measured in totally implanted ports, tunnelled or non-tunnelled single-lumen and multiple-lumen catheters. When the difference exceeds the limit of agreement, the discrepancy between the two measurements has limited significance in most cases.

Aged↗
PubMed2000

New tools in diagnosing catheter-related infections.

Clinical criteria alone are insufficient to allow a diagnosis of intravascular catheter-related sepsis (CRS). A definite diagnosis of CRS usually requires removal of the catheter for quantitative catheter tip culture. However, only about 15-25% of central venous catheters (CVC) removed because infection is suspected actually prove to be infected, and the diagnosis is always retrospective. Other diagnostic tests, such as differential quantitative blood cultures from samples taken simultaneously from the catheter and a peripheral vein, have been proposed to avoid unjustified removal of the catheter and the potential risks associated with the placement of a new catheter at a new site: a central-to-peripheral blood culture colony count ratio of 5:1 to 10:1 is considered indicative of CRS. Despite its high specificity, the latter diagnostic technique is not routinely used in clinical practice because of its complexity and cost. The measurement of the differential time to positivity between hub blood (taken from the catheter port) and peripheral blood cultures might be a reliable tool facilitating the diagnosis of CRS in situ. In an in vitro study, we found a strong relationship between the inoculum size of various microorganisms and the time to positivity of cultures. When the times to positivity of cultures of blood taken simultaneously from central and peripheral veins in patients with and without CRS were examined, we found that earlier positivity of central vs peripheral vein blood cultures was highly correlated with CRS. Using a cut-off value of +120 min, the "differential time to positivity" of the paired blood samples, defined as time to positivity of the peripheral blood minus that of the hub blood culture, had 91% specificity and 94% sensitivity for the diagnosis of CRS. This method may be coupled with other techniques that have high negative predictive value, such as skin cultures at the catheter exit site. This diagnostic test can be proposed for routine clinical practice in most hospitals using automatic devices for blood cultures positivity detection. Endoluminal brushing of the catheter is considered sensitive and specific for the diagnosis of CRS, but the risk of embolisation or subsequent bacteraemia should be considered. Gram staining and the acridine-orange leucocyte cytospin test on through-catheter blood culture have been proposed for rapid diagnosis of CRS without catheter removal. The technique, which requires 100 microl catheter blood and the use of light and ultraviolet microscopy, is considered simple, rapid (30 min) and inexpensive. In conclusion, diagnostic tools such as paired blood cultures or Gram staining and the acridine-orange leucocyte cytospin test should allow a diagnosis of CRS without catheter removal in cancer patients.

Algorithms↗
PubMed2000

Nutritional support of the cancer patient: issues and dilemmas.

Malnutrition in cancer patients results from multifactorial events and is associated with an alteration of quality of life and a reduced survival. A simple nutritional assessment program and early counselling by a dietitian are essential to guide nutritional support and to alert the physician to the need for enteral (EN) or parenteral nutrition (PN). A daily intake of 20-35 kcal/kg, with a balanced contribution of glucose and lipids, and of 0.2-0.35 g nitrogen/kg is recommended both for EN and PN, with an adequate provision of electrolytes, trace elements and vitamins. EN, always preferable for patients with an intact digestive tract, and PN are both safe and effective methods of administering nutrients. The general results in clinical practice suggest no tumor growth during nutritional support. The indiscriminate use of conventional EN and PN is not indicated in well-nourished cancer patients or in patients with mild malnutrition. EN or PN is not clinically efficacious for patients treated with chemotherapy or radiotherapy, unless there are prolonged periods of GI toxicity, as in the case of bone marrow transplant patients. Severely malnourished cancer patients undergoing major visceral surgery may benefit from perioperative nutritional support, preferably via enteral access. Nutritional support in palliative care should be based on the potential risks and benefits of EN and PN, and on the patient's and family's wishes. Research is currently directed toward the impact of nutritional pharmacology on the clinical outcome of cancer patients. Glutamine-supplemented PN is probably beneficial in bone marrow transplant patients. Immune diets are likely to reduce the rate of infectious complications and the length of hospital stay after GI surgery. Further studies are needed to determine the efficacy of such novel approaches in specific populations of cancer patients, and should also address the question of the overall cost-benefit ratio of nutritional pharmacology, and the effect of nutritional support on length and quality of life.

Cachexia↗
PubMed2000

Value of gram stain examination of lower respiratory tract secretions for early diagnosis of nosocomial pneumonia.

Except for bronchoalveolar lavage, the value of the Gram stain examination of respiratory tract samples for the diagnosis of hospital-acquired pneumonia (HAP) and their potential impact on empiric antibiotic treatment have rarely been assessed. During a 14-mo period, both plugged telescoping catheter (PTC) and endotracheal aspirate (EA) were performed when an HAP was suspected in mechanically ventilated patients. The results of Gram stain examinations and cultures and previous and subsequent antibiotic treatment were prospectively recorded. Two criteria for pneumonia were considered: (1) clinically diagnosed pneumonia, according to attending physicians, based on clinical and radiological evolution and the PTC culture results, and (2) microbiologically proven pneumonia (solely based on the result of quantitative PTC culture). Of 91 episodes of suspected HAP in 51 patients, 27 (30%) episodes were clinically diagnosed as pneumonia. When considering clinically diagnosed pneumonia, the sensitivity and specificity of Gram stain examination were similar (respectively, 89% and 62% for EA and 67% and 95% for PTC). When considering microbiologically proven pneumonia, the sensitivity and specificity of Gram stain examination were, respectively, 91% and 64% for EA and 70% and 96% for PTC. The negative predictive value of Gram stain examination of EA and the positive predictive value of Gram stain examination of PTC were high. Our results suggest that the combination of Gram stain examination of paired PTC and EA may contribute to the early diagnosis of HAP in about two-thirds of mechanically ventilated patients, and guide the empiric therapy when needed. In the remaining one-third of patients, the Gram stain examination is not helpful in predicting HAP.

Bacteria↗
PubMed2000

[Standards, Options and Recommendations (SOR) for the use of appetite stimulants in oncology. Work group. Federation of the French Cancer Centres (FNCLCC)].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines according to the definitions of the Standards, Options and Recommendations project for the use of appetite stimulants in oncology. METHODS: Data were identified by searching Medline and the personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 55 independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations for the use of appetite stimulants in oncology are: 1) Corticosteroids and the synthetic progestogens (megestrol acetate and medroxyprogesterone acetate) are appetite stimulants. 2) They can be useful in managing anorexia and weight loss in cancer patients, especially in the palliative setting, despite the potential side-effects of these agents. 3) The most effective way of using these drugs is not known. Inclusion in clinical trials is recommended. 4) Cyproheptadine, metoclopramide, nandrolone and pentoxif line should not be used outside prospective clinical trials. 5) Hydrazine sulfate should not be used.

Adrenal Cortex Hormones↗
PubMed2000

[Complications and tolerance of heated intraperitoneal chemotherapy and cytoreductive surgery for peritoneal carcinomatosis: results of a phase I-II study of peritoneal carcinomatosis from different sources].

Peritoneal carcinomatosis represents the terminal stage of adenocarcinomas of the gastrointestinal tract. A new treatment combining cytoreductive surgery and intraperitoneal chemotherapy-hyperthermia has been used with encouraging results. The purpose of this study was to report the complications associated with this treatment. Fourty procedures were carry out in 37 patients. Death occurred in 3 patients. Major medical complications were 13 pulmonary infections, 11 acute renal failure (with only 3 who needed dialysis) and 10 patients with neutropenia grade 3 and 4 toxicity. Intra-abdominal complications occurred in 16 patients (there were 11 anastomotic leak and/or bowel perforation, and 12 intra-abdominal infections). Some complications like secretory diarrhea or tubulopathia which were related to these treatment need further investigations. Six procedures were without any complications, 6 presented minor ones and 22 major complications. Adverse effects were relatively important with this new treatment strategy. This was maybe due to a learning process; there is no death and only one anastomotic leak in our last study including 30 patients with cytoreductive surgery and intraperitoneal chemotherapy-hyperthermia.

Adolescent↗
PubMed1999

[Is prevention of upper digestive system hemorrhage in intensive care necessary?].

Mucosal lesions are observed in 40 to 100% of critically ill patients. They are mainly due to gastric acid hypersecretion, biliary reflux, a decrease in mucosal defences, and digestive mucosal ischaemia. Acute upper gastrointestinal bleeding in intensive care unit (ICU) patients may occur, and if severe is associated with increased mortality and hospitalization costs. However, progress in the ICU management of patients, and especially in nutritional support, probably explains the low incidence of stress-induced gastrointestinal bleeding. Preventive strategies are indicated in high risk patients, i.e. when the risk of gastrointestinal bleeding is above 1%. Risk factors are not well defined presently, and probably include defective haemostasis and/or respiratory failure requiring prolonged ventilation assistance. Gastric hypersecretion can be well controlled with anti-H2 agents and sucralfate; these treatments improve the rate of complications but do not reduce overmortality related to gastrointestinal bleeding. Other drugs such as omeprazole are under investigation but due to insufficient clinical data and excessive cost, omeprazole cannot be recommended for this use. In addition, enteral nutritional support per se may efficiently prevent stress ulcers. Eradication of Helicobacter pylori has never been evaluated in this context. The selection of drugs today depends not only on efficacy and on costs, but also on possible adverse effects such as the putative risk of nosocomial pneumonia due to gastric bacterial overgrowth. Finally, only careful medico-economic evaluations of stress ulcer prophylaxis in ICUs will permit the implementation of valuable practice guidelines.

Acute Disease↗
PubMed1999

Diagnosis of catheter-related bacteraemia: a prospective comparison of the time to positivity of hub-blood versus peripheral-blood cultures.

BACKGROUND: A method of diagnosing catheter-related infection (CRI) without removing the catheter would be useful. An earlier positivity of central compared with peripheral venous-blood cultures may be associated with catheter-related bacteraemia. We evaluated prospectively the differential time to positivity (DTP) of paired blood cultures drawn simultaneously via the catheter hub and from a peripheral venous site. METHODS: Over a 14-month period in an intensive-care unit of a cancer referral centre, simultaneous hub-blood and peripheral-blood cultures (a mean of two per patient) were obtained from patients with a suspected CRI. According to clinical criteria and quantitative culture of the catheter tip, cases were classified as CRI or sepsis of other origin. At least one pair of hub-blood and peripheral-blood cultures was obtained within 48 h before catheter removal, and we recorded the DTP between hub-blood and peripheral-blood cultures with an automatic device for detection of blood culture positivity. FINDINGS: We analysed 93 catheters removed because of suspicion of CRI. In 28 episodes, the same micro-organisms were found in both hub-blood and peripheral-blood cultures. A diagnosis of definite bacteraemic CRI was made in 16 of the 17 patients in whom a positive hub-blood culture was detected at least 2 hours earlier than peripheral-blood culture. About half (9/17) of these episodes occurred in long-term (>30 days) devices. CRI was excluded in ten of the 11 patients with a DTP lower than 2 h. The DTP of paired blood cultures was significantly greater in patients with CRI than in others (p<10(-4)). A cut-off DTP value of 120 min had 91% specificity and 94% sensitivity for the diagnosis of CRI. Three of 17 episodes with only hub-blood culture positive were associated with CRI. INTERPRETATION: This prospective study suggests that measurement of the differential time to positivity between hub-blood and peripheral-blood cultures is a simple and reliable tool for in-situ diagnosis of catheter-related sepsis in cancer patients. Further studies are needed to confirm these data for short-term catheters.

Bacteremia↗
PubMed1999

Enteral nutrition in intensive care patients: a practical approach.

Severe protein-calorie malnutrition is a major problem in many intensive care (ICU) patients, due to the increased catabolic state often associated with acute severe illness and the frequent presence of prior chronic wasting conditions. Nutritional support is thus an important part of these patient's management. Over the years, enteral nutrition (EN) has gained considerable popularity, due to its favorable effects on the digestive tract and its lower cost and rate of complications compared to parenteral nutrition. However, clinicians caring for ICU patients are often faced with contradictory data and difficult decision-making when having to determine the optimal timing and modalities of EN administration, estimation of patient requirements and choice of formulas. The purpose of this paper is to provide practical guidelines on these various aspects of enteral nutritional support, based on presently available evidence.

Contraindications↗
PubMed1999

Diagnosis of nosocomial pneumonia in cancer patients undergoing mechanical ventilation: a prospective comparison of the plugged telescoping catheter with the protected specimen brush.

STUDY OBJECTIVES: Quantitative culture of protected samples of lower respiratory tract secretions obtained by a fiberoptic protected specimen brush (PSB) is widely accepted for the diagnosis of ventilator-associated pneumonia (VAP), but this diagnostic procedure is time consuming, expensive, and may give rise to iatrogenic complications, especially in cancer patients who often present with thrombocytopenia. The plugged telescoping catheter (PTC) could be a satisfactory alternative to the PSB in this setting. The aim of the present study was to evaluate the interest of the PTC to diagnose VAP in ventilated cancer patients. DESIGN: A prospective observational study. SETTING: A 15-bed medical-surgical ICU in a comprehensive cancer center. PATIENTS AND INTERVENTIONS: Over a 9-month period, 42 patients suspected of having bacterial VAP during mechanical ventilation underwent 69 bronchial samplings: a blinded PTC and a fiberoptic PSB were performed successively in each case. A positive culture for both sampling procedures was defined as the recovery of > or = 10(3) cfu/mL of at least one potential pathogen. The PSB result was taken as the reference standard. MEASUREMENTS AND RESULTS: The overall agreement between the techniques was 87% (60/69). PTC had a sensitivity of 67%, a specificity of 93%, a positive predictive value of 71%, and a negative predictive value of 91%. CONCLUSIONS: We conclude that the accuracy of the blinded PTC compares well with that of the PSB for the diagnosis of VAP in cancer patients. The sensitivity of the PTC observed herein, which is slightly lower than that described in previous studies, may be due to the blinded nature of the method: the indications for initial or secondary coupling with a directed sampling method in patients with suspicion of localized pneumonia remain to be determined.

Bacteria↗
PubMed1998

Circumferential pharyngolaryngectomy with total esophagectomy for locally advanced carcinomas.

BACKGROUND: Forty-nine cases of circumferential pharyngolaryngectomy with total esophagectomy (PLTE) done between 1982 and 1996 were studied retrospectively. These procedures were performed for advanced squamous cell tumors of the superior esophageal sphincter (n = 23), for hypopharyngeal tumors with synchronous esophageal carcinoma (n = 15), and for hypopharyngeal tumors extensively invading the cervical esophagus (n = 11). METHODS: Ninety-six percent of the patients had T3-4 lesions, and it was impossible to use a free jejunal graft reconstruction. Patients underwent primary surgery in 70% of the cases, and salvage surgery (after failure of chemoradiotherapy) in 30%. In most patients, esophagectomy was performed without thoracotomy (n = 45). Resection was curative (R0) in 70% of the cases, in spite of lymph node invasion in 94%. Reconstruction of the digestive tract was achieved with the stomach in 33 patients (67%) or with the colon in 16 patients (33%). RESULTS: Before 1989, postoperative mortality was high, was correlated with the high frequency of palliative surgery, and resulted in unsatisfactory survival results (overall 5-year survival rate of 7%). After 1989, as a result of better selection of patients and appropriate training of our team, postoperative mortality decreased from 33% to 10%, R1-2 resections decreased from 39% to 26%, and a 3-year overall survival rate of 28% was obtained for the last 25 patients, all of whom were able to eat without difficulty. These results are superior to the survival rates and functional results obtained with radiochemotherapy alone for such advanced tumors, even though the voice is preserved with radiochemotherapy alone. CONCLUSIONS: PLTE for advanced pharyngeal or cervical esophageal tumors is the best treatment currently available, but it is indicated only in very selected cases: when it is technically impossible to perform reconstruction with a free jejunal graft after circumferential pharyngolaryngectomy; as primary surgery, rather than as salvage surgery following chemoradiotherapy; after careful preoperative morphologic and endoscopic assessment of the extent of the tumor; and in patients able to tolerate a thoracotomy for an esophagectomy with lymphadenectomy. Selection according to these guidelines should improve results.

Adult↗
PubMed1998

Epidemiology, diagnosis and treatment of systemic Candida infection in surgical patients under intensive care.

The incidence of systemic Candida infections in patients requiring intensive care has increased substantially in recent years as a result of a combination of factors. More patients with severe underlying disease or immunosuppression from anti-neoplastic or anti-rejection chemotherapy and at risk from fungal infection are now admitted to the ICU. Improvements in supportive medical and surgical care have led to many patients who would previously have died as a result of trauma or disease surviving to receive intensive care. Moreover, some therapeutic interventions used in the ICU, most notably broad-spectrum antibiotics and intravascular catheters, are also associated with increased risks of candidiasis. Systemic Candida infections are associated with a high morbidity and mortality, but remain difficult to diagnose and ICU staff need to be acutely aware of this often insidious pathogen. A number of studies have identified risk factors for systemic Candida infection which may be used to identify those at highest risk. Such patients may be potential candidates for early, presumptive therapy. Here we review the epidemiology, pathogenesis, morbidity and mortality of systemic Candida infections in the ICU setting, and examine predisposing risk factors. Antifungal treatment, including the use of amphotericin B, flucytosine and fluconazole, and the roles of early presumptive therapy and prophylaxis, is also reviewed.

Antifungal Agents↗
PubMed1998

Enteral nutrition in intensive care patients: a practical approach. Working Group on Nutrition and Metabolism, ESICM. European Society of Intensive Care Medicine.

Severe protein-calorie malnutrition is a major problem in many intensive care (ICU) patients, due to the increased catabolic state often associated with acute severe illness and the frequent presence of prior chronic wasting conditions. Nutritional support is thus an important part of the management of these patients. Over the years, enteral nutrition (EN) has gained considerable popularity, due to its favorable effects on the digestive tract and its lower cost and rate of complications compared to parenteral nutrition. However, clinicians caring for ICU patients are often faced with contradictory data and difficult decisions when having to determine the optimal timing and modalities of EN administration, estimation of patient requirements, and choice of formulas. The purpose of this paper is to provide practical guidelines on these various aspects of enteral nutritional support, based on presently available evidence.

Cost-Benefit Analysis↗
PubMed1998

Pharmacokinetic assessment of an oligopeptide-based enteral formula in abdominal surgery patients.

The specific effect of the molecular form of the nitrogen supply (oligopeptides and whole proteins) on amino acid kinetics during enteral feeding after surgery has not been assessed previously. In a prospective, randomized study, patients having undergone esophagectomy or gastrectomy for cancer received jejunal infusions of oligopeptide-based or whole-protein-based complete formulas (OPD and WPD, respectively) during two 9-h periods on 2 consecutive days in a crossover design. The OPD and WPD had identical energy compositions and amino acid profiles. Amino acid peripheral bioavailability (measurements of area under the curve of arterial blood concentrations), amino acid arteriovenous differences, and insulin and glucagon responses were measured. Amino acid peripheral bioavailability was higher (leucine: 54%, P < 0.01; essential amino acids: 48%, P < 0.01; total amino acids: 53%, P < 0.02) and peripheral appearance of amino acids was more homogeneous (variation around the calculated plateau of plasma leucine was 39% for OPD and 78% for WPD, P < 0.001) with the OPD than with the WPD. With the OPD, insulin stimulation was faster and plasma concentrations of leucine and insulin were correlated (r = 0.77, P < 0.01). The OPD led to a higher amino acid peripheral bioavailability than the corresponding WPD. These results could be useful for a better definition of clinical indications of semi-elemental diets.

Abdomen↗
PubMed1998

Severity-of-illness scores for neutropenic cancer patients in an intensive care unit: Which is the best predictor? Do multiple assessment times improve the predictive value?

OBJECTIVES: To use three severity of illness scores to estimate the probability of hospital mortality among patients with cancer and neutropenia; to compare the performance of these scores, calculated at admission to an intensive care unit (ICU); and to test the improvement in estimation obtained by taking into account the first 72-hr period. DESIGN: Collection of data for every neutropenic patient hospitalized in the ICU during a 4-yr period. SETTING: A comprehensive cancer center. PATIENTS: Ninety-four patients were neutropenic at ICU admission. Their vital status was measured at hospital discharge. MEASUREMENTS AND MAIN RESULTS: The new Simplified Acute Physiology Score (SAPS) II improved the estimation of hospital mortality compared with the original SAPS score. Using a simple score based on the number of acute organ system failures (OSFs) to classify the patients, good discrimination between survivors and nonsurvivors was observed (area under the receiver operating characteristic curves, 79 +/- 5 [SD] %). The relationship between successive scores and outcome was explored using recursive partitioning. Patients were first classified according to their OSF value on the first day of hospitalization in the ICU with a cutoff of two organ failures, and classification was then improved by taking into account the OSF score on the third day. CONCLUSIONS: For cancer patients hospitalized in an ICU for a neutropenic episode, the severity of illness and the risk of death can be accurately assessed by the SAPS II score and the number of acute organ failures at admission. The OSF values on the first and third days of hospitalization both provided information, allowing the classification of patients into groups with different probabilities of hospital mortality.

APACHE↗
PubMed1998

Earlier positivity of central-venous- versus peripheral-blood cultures is highly predictive of catheter-related sepsis.

To diagnose catheter-related sepsis without removing the catheter, we evaluated the differential positivity times of cultures of blood drawn simultaneously from central venous catheter and peripheral sites. In a 450-bed cancer reference center, simultaneous central- and peripheral-blood cultures were prospectively performed for patients with suspicion of catheter-related sepsis over an 18-month period. Data for 64 patients for whom the same microorganisms were found when central- and peripheral-blood samples were cultured were retrospectively reviewed by two independent physicians blinded to the differential positivity time values in order to establish or refute the diagnosis of catheter-related sepsis. The diagnosis was established in 28 cases, refuted in 14, and indeterminate in the remaining 22. The differential positivity time was significantly greater for patients with catheter-related sepsis (P < 10(-4)). A cutoff limit of +120 min had 100% specificity and 96.4% sensitivity for the diagnosis of catheter-related sepsis. These results strongly suggest that measurement of the differential positivity time might be a reliable tool facilitating the diagnosis of catheter-related sepsis in patients with an indwelling catheter.

Catheterization, Central Venous↗