ELISA D-dimer measurement for the clinical suspicion of pulmonary embolism in the emergency department: one-year observational study of the safety profile and physician's prescription.

OBJECTIVES: To validate the safety profile of a rapid ELISA D-dimer as the first diagnostic step in the clinical suspicion of pulmonary embolism (PE) in outpatients admitted to an emergency department (ED), and to retrospectively evaluate the appropriateness of the physician's prescription. DESIGN AND SETTING: An observational study of all patients admitted to the ED of an urban university teaching hospital with signs and symptoms justifying the prescription of a rapid ELISA D-dimer measurement (Vidas; Biomerieux; France) as the first line diagnostic test for PE. Acute PE was established or excluded according to an appropriate combination of the D-dimer concentration, the lung scintigraphy, the spiral computerized tomography (spiral CT), the venous ultrasonography, and the arteriography in case of uncertain results. All patients with D-dimer values under the cut-off point of 500 ng/ml were followed up after 6 months. RESULTS: 395 patients were studied. A normal D-dimer concentration < 500 ng/ml was found in 179 patients (45% of the cohort). The retrospective analysis showed that none of these patients were found to have a high pre-test clinical probability. None of these 179 patients received anticoagulation nor displayed a PE event during a 6-month period (negative predictive value 100%; 95% CI, 98.0 to 100%; sensitivity 100%; 95% CI, 90.3 to 100%). Among the 216 patients (55%) with D-dimer values above 500 ng/ml, PE was confirmed in 32 cases, for a prevalence of the disease of 8.1%. Eighty-six patients (22%) had no additional testing in spite of positive D dimer values > 500 ng/ml, pointing out a 22% rate of inappropriate use of the D-dimer measurement. CONCLUSION: This observational study confirms that a normal rapid ELISA D-dimer value (< 500 ng/ml) used as a first diagnostic step in ruling out the diagnosis of PE is a safe clinical practice when the pre-test clinical probability is low or intermediate. Nevertheless, the low prevalence rate of the disease (8.1%) suggests a potential overused and inappropriate prescription.

[Validation of a triage scale: first step in patient admission and in emergency service models]. / Validation d'une grille de tri: première étape dans l'analyse du flux des patients et dans la modélisation d'un service d'urgence.

INTRODUCTION: At present, most emergency services handle the multitude of various demands in the same unity of place and by the same team of nurses aides, with direct consequences on the waiting time and in the handling of problems of varying degrees of importance. Our service examines other administrative models based on a triage of time and of orientation. METHODS AND RESULTS: In a prospective study on 679 patients, we have validated a triage tool inspired from the ICEM model (International Cooperation of Emergency Medicine) allowing patients to receive, while they wait, information and training, based on the resources provided, in order to deal with their particular medical problem. CONCLUSION: The validation of this tool was carried out in terms of its utilization as well as its reliability. It appears that, with the type of triage offered, there is a theoretical reserve of waiting time for the patients in which the urgency is relative, and which could be better used in the handling of more vital cases.

Chylous ascites: diagnosis, causes and treatment.

Chylous ascites is a rare form of ascites and generally associated with a poor outcome since it is often secondary to neoplasms. Its true incidence is not well established in the general medico-surgical population. Any source of lymph vessels obstruction or leakage can potentially cause chylous effusions in the peritoneal or retroperitoneal cavities. Any type of cancer and lymph node involvement may be associated with this uncommon type of ascites. Traumatic, and mainly surgical, vessels leakage is the second most common source of chylous effusions. Other even more rare underlying conditions have been described as leading to chyloperitoneum. Large fluid volume losses together with proteins, and lymphocytes can induce additional morbidity in a previously debilitated population or severely ill patients. This includes organ dysfunction related to volume and electrolytes losses, but mainly secondary infections due to impaired immunity by antibodies and lymphocytes depletion. Even if a vast majority of chylous effusions shall heal spontaneously, early and full treatment has to be initiated in order to reduce morbidity and mortality associated with this condition. Adapted oral diet is to be introduced to reduce lymph flow. Low lipid, high medium-chain triglycerides alimentation is the first measure to implement. Total parenteral nutrition is to be reserved to failures of oral diet. In addition, paracentesis is indicated to improve patient comfort, reduce intra-adbominal pressure and secondary renal dysfunction. Somatostatin analogues have been demonstrated to be effective in reducing lymphorragia and may be proposed prior to consider the surgical approach. Direct lymph vessels ligation can be indicated for large lymph vessels leakage demonstrated by radiologic techniques and when medical treatment has failed. Peritoneo-venous shunt becomes a less common technique in refractory chylous effusion because of its high morbidity. Herein, the other causes of chylous effusions are reviewed as the diagnostic procedures. A treatment algorythm is proposed.

Ascites fluid in severe acute pancreatitis: from pathophysiology to therapy.

Several pathophysiological mechanisms are involved in the development of the inflammatory necrotizing process that takes place in the retroperitoneal area during the early phase of acute pancreatitis. They include premature intraglandular activation of pancreatic proenzymes (zymogens) and in particular trypsin, early microcirculatory impairment with subsequent ischaemia/reperfusion and overstimulation of immune effector cells. Although intra-acinar or interstitial activation of trypsinogen is most probably the trigger of acute pancreatitis, in recent years much emphasis has been put on the role of leukocytes. Based on numerous experimental and human data several pro-inflammatory mediators including cytokines, arachidonic acid derivatives, activated oxygen species and proteases are released locally by overactivated neutrophils and monocytes/macrophages among other cells. They are now believed to play a central role in the development of pancreatic necrosis and, once they gain access to the systemic circulation, in the emergence of early multisystem organ failure. However the sequential and relative contribution of each of these 3 pathophysiological mechanisms remain controversial and the precise identification of the mediators incriminated in local and remote tissue injury is still awaited. Severe acute pancreatitis still carries a mortality of 20% to 30%. With advances in intensive care management 80% of the deaths occur somewhat late in the attack due to infected pancreatic necrosis. Nevertheless early remote organ failures still remain a lifethreatening condition for most of these patients. A peritoneal exudate rich in activated lipolytic and proteolytic enzymes, vasoactive substances and several other pro-inflammatory mediators collect in over 60% of the patients with severe acute pancreatitis. On the basis of favourable animal experiments early percutaneous or surgical peritoneal lavage with or without the addition of antiproteases has been carried out in human acute pancreatitis. The rationale behind this procedure was the washout of potential toxic mediators from the peritoneal cavity before they gain access to the systemic circulation. Contrary to animal and uncontrolled human data no prospective randomized study could ever demonstrated a significant effect of peritoneal lavage neither in the prevention and control of remote organ failures or in early mortality and ultimate survival after severe acute pancreatitis in humans. Differences between experimentally-induced pancreatitis, difference in the timing of the initiation of lavage and a type II error in controlled human studies may account for the discrepancy in the outcome between these studies. Anyway, this disparity should raise the question as whether the peritoneal cavity acts simply as a reservoir or as a route of transfer of toxic mediators to the systemic circulation. Although data are scarce, conflicting and limited to animal experiments and to a few molecules, peripancreatic veins and lymphatics seem to be the major routes of transfer whereas transperitoneal absorption is trivial. Nevertheless early peritoneal aspiration of ascitic fluid in acute pancreatitis and measurement of trypsinogen activation peptides may be used as a means of severity assessment and identification of pancreatic necrosis. This implies that even if not taking part actively in the emergence of remote organ failures ascitic fluid may reflect the peripancreatic necrotizing process. So careful comparative analysis of peritoneal exudate, plasma and lymph with regards to putative mediators of local and remote injury may provide essential pathophysiological clues. At the time of trials of antimediator therapy early in the attack this kind of insight is essential.

Adult liver transplantation: the Université Catholique de Louvain experience.

Liver transplantation remains a formidable surgical and medical procedure. The larger single centre experience confirms that standardization of perioperative care and simplification of the surgical procedure markedly improve results. Further efforts must be made in relation to immunosuppressive therapy in order to minimize late morbidity and mortality.

[Radiology and emergency medicine: state of the art]. / Radiologie et medecine d'urgence: etat de la question.

Emergency medicine has emerged as a specific medical specialty for 30 years. To be efficient, the emergency clinician frequently needs the contribution of radiological examinations. This is the reason why emergency radiology has emerged as a new radiologic subspecialty. The aim of this paper is to review the recent history of emergency medicine and to summarize the present state of the radiological organisation for emergency care in the Western countries.

Severe acute pancreatitis: pathophysiologic mechanisms underlying pancreatic necrosis and remote organ damage.

Despite advances in surgical and intensive care the mortality of severe acute pancreatitis still ranges between 10 and 20%. Fundamentally, the severity of acute pancreatitis, both in term of propensity and intensity of locoregional and remote complications, relies on the development of regional necrosis, the extent of the necrotizing process and the bacterial contamination of these necrotic areas. Intraacinar activation of pancreatic enzymes, overstimulation of inflammatory effector cells and vascular mechanisms are the 3 inter-related factors, acting sequentially to promote the severity of the inflammatory reaction, the ensuing necrosis and the emergence of locoregional complications. Numerous toxic substances, including inflammatory mediators, are released by this inflammatory retroperitoneal necrotizing process, gain access to the systemic circulation and mediate remote organ dysfunctions. Nowadays, pancreatic infection whose occurrence is mainly dependent upon the volume of necrosis and secondary bacterial translocation from the gut, accounts for 80% of the mortality in acute pancreatitis. The understanding of the pathophysiologic mechanisms underlying the inflammatory necrotizing process is critical so that the extent of necrosis can ultimately be limited at an early stage and these patients may be granted a better outcome.

Respiratory failure due to tracheobronchomalacia.

A case is described of tracheobronchomegaly progressing to extensive tracheomalacia, complicated by episodic choking, recurrent pulmonary infections, and irreversible hypercapnic respiratory failure. A Y-shaped tracheobronchial stent was placed endoscopically to splint the trachea open, with excellent clinical and physiological improvement. New stent designs may provide long term palliation in selected cases of diffuse tracheal collapse or stenosis, and offer an alternative to surgical repair.

Transjugular intrahepatic portosystemic shunt and liver transplantation.

Transjugular intrahepatic portosystemic stent shunting (TIPSS) appears to be an attractive, nonsurgical procedure to overcome complications of end-stage liver disease. During the period August 1992 to February 1995, 23 adults who had previously undergone TIPSS received liver transplants. These patients were compared to 36 cirrhotic patients, grafted during the same time period, in relation to the implantation technique, the intraoperative use of blood products, and the length of their hospital stay. These groups were comparable for previous right upper quadrant surgery, splanchnic vein modifications, and Child-Pugh classification. Liver transplantation was performed electively in all TIPSS patients. Ten patients (43.4%) presented with a significant shunt stenosis at a median follow-up time of 4.5 months (range 2.5 to 30 months). At transplantation 8 of the 23 TIPSS patients (34.8%) had specific TIPSS-related modifications i.e., extrahepatic portal vein aneurysm formation (n = 2), dislocation of the distal end of the stent into the inferior vena cava (n = 4) or into the main portal vein trunk (n = 1), bilioportal fistula (n = 1), and pronounced phlebitis of the inferior vena cava and hepatic veins due to redilation of shunt stenosis (n = 4). The intraoperative blood product requirement at transplantation was similar in the 23 TIPSS-patients and in the 36 cirrhotic patients who received transplants without the TIPSS procedure during the same time period [median 800 ml (range 0-20300 ml) vs median 620 ml (range 0-7600 ml), respectively]. There was also no difference between the two groups in length of hospital stay [median 18 days (range 0-34 days) vs median 19 days (range 0-66 days), respectively]. We conclude that TIPSS plays an important role in the management of life-threatening complications of end-stage liver disease arising in potential liver transplant candidates. TIPSS should be considered as a temporary, effective bridge to elective transplantation and not as a means to lower the blood product requirement at transplantation. Specific TIPSS-related modifications should be recognized early by the transplant surgeon in order to adapt the technique of graft implantation.

Sequential treatment of hepatorenal syndrome and posthepatic cirrhosis by intrahepatic portosystemic shunt (TIPSS) and liver transplantation.

The results of liver transplantation are compromised in cirrhotic patients presenting with renal insufficiency from hepatorenal syndrome. A case of cirrhosis and hepatorenal syndrome, treated sequentially with transjugular intrahepatic porto-systemic stent shunting (TIPSS) and liver transplantation, is discussed. TIPSS may be useful for correcting renal dysfunction and/or hepatorenal syndrome in end-stage cirrhotics, thus permitting subsequent elective liver transplantation under good conditions.

Extensive lymph node clearance for cancer of the esophagus or cardia: merits and limits in reference to 5-year absolute survival.

BACKGROUND/AIMS: The present study evaluates both merits and limits of extensive lymph node clearance in the mediastinum and upper abdomen on patients operated on more than 5 years ago. MATERIALS AND METHODS: One hundred forty-four esophageal cancer patients underwent subtotal (n = 97) or distal (n = 47) esophageal resection more than 5 years ago. Twenty-six patients operated on in a curative attempt were given radiotherapy (n = 14) or radiochemotherapy (n = 12). RESULTS: Esophagectomy with extensive lymph node clearance was feasible in 102 of the 144 patients (70.8%). In-hospital mortality was 1.4%. Thirty-six patients lived more than 5 years, ie. 25% of all the esophagectomized patients and 35.3% (36/102) of those who were operated on in a curative attempt. Five-year absolute survival was 38.4% after combined therapy v.s. 34.2% after surgery alone (p > 0.05). In the latter instance, it was 57.1% for those patients with normal lymph nodes v.s. 14.6% for those with metastatic lymph nodes, and it was 64% for those with non-transmural tumors v.s. 19.6% for those with transmural tumors. One half of those patients who were not given adjuvant therapy following esophagectomy with extensive lymph node clearance died of neoplastic spread, namely distant metastases (27.6%), cervical spread (3.9%), and local recurrence (10.5%). CONCLUSIONS: Esophagectomy with extensive lymph node clearance is not feasible in 30% of the patients in whom it is attempted, and it does not prevent further neoplastic spread in one half of those in whom it is feasible. It is capable of curing 15 to 20% of those patients with locally advanced neoplasms and shelters 90% of the patients from local recurrence.

Liver transplantation and haemophilia A.

Liver transplantation has become the standard treatment for a variety of inherited metabolic disorders. We report on two patients who underwent successful transplantation for posthepatitis viral cirrhosis, which developed following blood factor replacement for haemophilia A. The second patient was transplanted before the occurrence of major complications of either his liver or haemophilic disease. We propose early liver transplantation to achieve metabolic cure of haemophilia.

Significance of pathologic oxygen supply dependency in critically ill patients: comparison between measured and calculated methods.

OBJECTIVE: oxygen supply dependency at normal or high oxygen delivery rate has been increasingly proposed as a hallmark and a risk factor in critical illnesses. We hypothesized that as far as an adequate oxygen delivery is provided, oxygen consumption, when determined by indirect calorimetry, is not dependent on oxygen delivery in critically ill patients whereas calculated oxygen consumption is associated with artefactual correlation of oxygen consumption and delivery. DESIGN: oxygen delivery, oxygen consumption and their relationship were analyzed prospectively. Metabolic data gained from both measured and calculated methods were obtained simultaneously before and after volume loading. SETTING: the study was completed in the intensive care unit as part of the management protocol of the patients. PATIENTS: 32 consecutive patients entered the study and were divided into 3 groups according to a clinical condition known to favour oxygen supply dependency: sepsis syndrome, adult respiratory distress syndrome and acute primary liver failure. INTERVENTION: the rise in oxygen delivery was obtained by colloid infusion (oxygen flux test) performed in hemodynamically and metabolically stable patients. All were mechanically ventilated. No change in therapy was allowed during the test. MEASUREMENTS AND RESULTS: oxygen consumption was simultaneously evaluated by calculation (Fick Principle) and direct measurement using indirect calorimetry. Oxygen delivery was derived from the cardiac output (thermodilution) and arterial content of oxygen. Oxygen supply dependency was considered while observing an increase in oxygen delivery greater than 45 ml/min.m2. Irrespective of patient's clinical diagnosis and outcome, measured oxygen uptake remained unaltered by volume infusion whereas both oxygen delivery and calculated oxygen consumption increased significantly. Arterial lactate level > 2 mmol/l and measured oxygen extraction ratio > 25% failed to identify oxygen supply dependency when measured data were considered. CONCLUSION: analysis of oxygen uptake, when measured by indirect calorimetry, failed to substantiate oxygen supply dependency in the vast majority of the critically ill patients irrespective of diagnosis and outcome. Mathematical coupling of shared variables accounted for the correlation between oxygen delivery and calculated oxygen consumption.

Evaluation of oxygen uptake and delivery in critically ill patients: a statistical reappraisal.

OBJECTIVE: The evaluation of oxygen consumption (VO2) and oxygen delivery (DO2) has gained increasing importance in the monitoring of critically ill patients. They can be obtained from either direct measurements or by indirect calculations based on the Fick principle. However the choice between these two approaches remains controversial. The aim of the study was to investigate whether these 2 methods provide similar results, and if not, to define the best one in terms of reproducibility. DESIGN: Oxygen delivery and oxygen consumption were prospectively analyzed in 171 consecutive critically ill patients. Metabolic data were obtained simultaneously. SETTING: The study was completed in the intensive care unit as part of the management of the patients studied. PATIENTS: A first "group" of 279 evaluations was carried out in 73 consecutive critically ill patients. The results were subsequently validated by 423 observations performed in the 98 following patients. INTERVENTIONS: Before and during each evaluation, the patients were kept in stable hemodynamic and metabolic conditions. All were mechanically ventilated. MEASUREMENTS AND RESULTS: VO2 was evaluated by calculation (Fick principle) and direct measurement using indirect calorimetry. Cardiac output was both measured by the thermodilution technique and calculated (Fick principle) and the data were used for the evaluation of the directly measured and indirectly calculated DO2. For both VO2 and DO2 the agreement between direct and indirect evaluations was not satisfactory. Differences as great as 55 ml/min.m2 and 267 ml/min.m2 between simultaneously measured and calculated VO2 and DO2 respectively may be expected. Finally, the indirect calculated methods were less reproducible than the measured ones. These observations resulted mainly from the cumulative effects of the random errors in the metabolic data entering into the calculation of VO2 and DO2. CONCLUSIONS: Our data suggested that the indirect calculation (Fick equation) and the direct measurement (indirect calorimetry, thermodilution) of both VO2 and DO2 did not provide similar results. Direct measurements are more reproducible methods and must be preferred.

[Clinical evaluation, evolution and intensive care treatment of severe acute pancreatitis]. / Evaluation clinique, évolution et traitement aux soins intensifs des pancréatites aiguës sévères.

Severe acute pancreatitis is morphologically characterized by an intense and necrotizing inflammatory process responsible for early remote organ dysfunctions and late regional complications. Retroperitoneal necrosis has to be identified early by several biological markers and abdominal CT study. A better understanding of the pathophysiological mechanisms underlying the natural history of severe acute pancreatitis, progress in intensive care support and the emergence of new conservative or surgical strategies aimed at removing the necrotic areas and their toxic by-products have led to a dramatic reduction in early and overall mortality for the patient with this disease.

Retroperitoneal laparostomy: a surgical treatment of pancreatic abscesses after an acute necrotizing pancreatitis.

BACKGROUND: From 1982 to 1988, 20 patients with pancreatic abscesses after an acute necrotizing pancreatitis underwent a retroperitoneal laparostomy (RPL). METHODS: The severity of the disease was assessed by Ranson's bioclinical and Hill's computed tomographic scoring systems. The RPL, guided by the results of repeated computed tomographic scans (high frequency of peripancreatic necrotic extension through the anterior pararenal space) consists of a left or right lateral incision under the twelfth rib, allowing direct access to the pancreas and peripancreatic spaces. RESULTS: Four patients (20%) had local complications: colonic fistula (one patient), gastric and colonic fistula (one patient), jejunal fistula (one patient), and local hemorrhage (one patient). Only one complication was lethal (gastric and colonic fistula). Four patients died (mortality rate 20%). In two of the cases death was related directly to a persistent sepsis after the RPL, whereas the two other patients died despite a complete surgical drainage. CONCLUSIONS: RPL (left or right, sometimes bilateral) allows a total exploration of the pancreas and peripancreatic spaces in most cases, as well as a complete manual removal of the necrotic infected masses. Furthermore, several second-look removals of newly formed necrotic masses can be performed without the risk of peritoneal contamination and with a low rate of digestive fistula.

[Respiratory complications in severe acute pancreatitis]. / Les complications respiratoires de la pancréatite aiguë sévère.

The two basic mechanisms underlying most of the pleuropulmonary complications of severe acute pancreatitis include pulmonary atelectasis and alveolar flooding. Like in any abdominal catastrophe, pleural effusion and limited diaphragmatic excursion due to pain and intestinal atony are the main factors responsible for alveolar collapse and secondary infection. Physical therapy and needle pleural evacuation are the cornerstones of management. Owing to its pathophysiologic mechanisms adult respiratory distress syndrome is peculiar to acute pancreatitis. Alveolar capillary membrane injury is related to pancreatic necrosis, to its regional extent and to the subsequent over-amplification of the inflammatory reaction. Diversion of those potential mediators of the syndrome either surgically or by thoracic duct drainage is essential in order to improve survival in these patients.

The effect of peritoneal dialysis with and without aprotinin on acute experimental pancreatitis in rats.

Acute pancreatitis was induced in 139 Wistar rats by injection of trypsin in the common bilio-pancreatic duct. Peritoneal dialysis was performed in 93 rats. In some of these rats, aprotinin (250,000 UI/L) was added to the lavage fluid. Macroscopically, we noted the amount of steatonecrosis, pulmonary congestion and pleural effusion produced. The pancreatic and pulmonary lesions were studied microscopically. The effect of peritoneal dialysis with and without aprotinin on the survival rate was evaluated. Survival curves were established for the different groups of rats i.e. the non-treated group and the two groups of dialysed rats (with and without aprotinin). Peritoneal dialysis reduces the amount of steatonecrosis and the incidence of pulmonary complications of trypsin-induced pancreatitis in rats, but does not influence the pancreatic lesions. Peritoneal dialysis significantly improves the early survival rate. Addition of aprotinin to the dialysis fluid reduces the total mortality rate.