[The number needed to treat (NNT)]. / Le nombre de sujets qu'il est nécessaire de traiter (NST).

The number needed to treat (NNT) is a valuable information in treatment decisions. This is the result of a calculation based on published data, collected from an intervention study. NNT is the inverse of the absolute risk reduction (1/ARR) between two treatment options. It is always expressed by a value rounded up to whole numbers, between 1 and infinity, depending on the effectiveness of the new treatment being studied. The NNT is the average number of patients needed to be treated for a duration equal to the study period to achieve one additional positive response under the conditions of the study. The more the treatment will be effective, the more the NNT will be low (tending towards 1). The NNT should be calculated based on the results of a clinical study of good methodological quality, involving a well-defined and homogeneous group of patients, whose baseline risk is known and using a dichotomous endpoint (the event occurs or not). The study must have shown a statistically significant difference between the two groups. In the process of medical decision making, the NNT must be balanced with the safety profile of the treatment (represented by the number needed to harm, or NNH), the costs and stress associated with it. It is possible to calculate a NNT and its confidence interval, from the published data of a clinical study. Some authors report the NNT in the text of the publication.

[Pulmonary embolism and inferior vena cava agenesis: An unusual association]. / Embolie pulmonaire et agénésie de veine cave inférieure : une association inhabituelle.

INTRODUCTION: Inferior vena cava agenesis is a rare congenital anomaly, generally associated with thrombophilic conditions, and a predisposing factor for deep venous thrombosis (DVT), rarely complicated by pulmonary embolism, in a young population with atypical clinical features and frequent absence of risk factors. CASE REPORT: We report the case of a 30-year-old woman who developed a right iliac DVT, initially presenting as a low back pain and complicated by a pulmonary embolism, 8 months after a sleeve gastrectomy. Chest CT angiography revealed abnormalities that led to the diagnosis of inferior vena cava agenesis. Thrombophilic screening showed a heterozygous prothrombin gene mutation G20210A and hyperhomocysteinemia. The patient was treated with rivaroxaban with good results after 2 years of follow-up. CONCLUSIONS: In young patients without risk factors developing a deep venous thrombosis, an inferior vena cava anomaly should be considered. Although no therapeutic consensus has been currently established, inferior vena cava agenesis seems to be associated with a high prevalence of thrombophilic disorders. Screening could be useful, particularly in patients with a thrombotic family history.

[Platypnea, orthodeoxia A report of two cases]. / Platypnée, orthodéoxie À propos de deux cas.

The plathypnea orthodeoxia syndrome is a rare condition that is characterized by dyspnea and hypoxia that occurs in the upright position and improves with recumbency. The diagnostic is often made tardively and requires the combination of two components: a mechanical one (for example a patent foramen ovale) and a kinetic one (for example COPD). This combination contributes to the blood flow through the communication. The treatment consists of closing the veno-arterial communication (in the case of a patent foramen ovale, the closing of the inter-atrial septum) (Knapper et al, 2014). In the present article, we describe two severe hypoxemic patients suffering from this syndrome. Both cases were associated with an acute pulmonary disease. A review of the literature is performed.

Operating characteristics of the Finapress system to predict elevated left ventricular filling pressure.

BACKGROUND: Dyspnea is a common symptom and can be caused by many different conditions. The detection of congestive heart failure (CHF) is sometimes difficult. HYPOTHESIS: The pulse amplitude ratio (PAR) measured by the Finapress procedure during a Valsalva maneuver can detect elevated left ventricular end-diastolic pressure (LVEDP) accurately over a wide range of values. METHODS: Comparison of the estimated LVEDP by PAR with the invasively measured LVEDP before and after ventriculography during coronography was made in 101 consecutive stable patients referred for chest pain and/or chronic dyspnea. RESULTS: A significant correlation was found between the catheter-measured LVEDP (range 3-40 mmHg) and the PAR (R2 = 0.70, p < 0.001). The receiver operator characteristics (ROC) of the PAR to detect an LVEDP > 15 mmHg can be considered to be excellent, with an area under the ROC curve achieving 0.92 (95% confidence interval [CI] 0.87-0.96; p < 0.001). A PAR of > 0.675 predicted the presence of an LVEDP > 15 mmHg with a sensitivity of 0.865 (95% CI 0.780-0.926) and a specificity of 0.847 (95% CI 0.730-0.928). The positive and negative LRs were 5.70 and 0.16, respectively. CONCLUSIONS: The observed likelihood ratios confirm that the PAR determined by the Finapress procedure may be a useful bedside diagnostic tool in patients with cardiac conditions.

[Hemoptysis in a young man]. / Hémoptysies chez un jeune homme.

INTRODUCTION: We describe the development of severe and recurrent alveolar hemorrhage in a 30 year old man. The patient had presented with frank hemoptysis, that recurred after an interval of 4 weeks, associated with dyspnea and severe anemia requiring transfusion. The chest x-ray and CT scan showed bilateral diffuse ground glass shadows. Fibreoptic bronchoscopy confirmed bilateral diffuse bleeding. Investigations for the common causes of diffuse alveolar hemorrhage (immunological, infective) proved to be negative on two occasions. Toxicological examination of the urine during the relapse revealed a significant level of cannabis and a trace of cocaine. The patient repeatedly denied the use of illicit drugs. CASE REPORT: Because of the general condition of this young patient a lung biopsy was performed by video-thoracoscopy. This showed evidence of diffuse alveolar damage compatible with inhalation of cocaine. Faced with these results the patient admitted that he regularly smoked "improved joints". CONCLUSION: This clinical observation emphasises that the inhalation of cocaine is a cause of diffuse alveolar hemorrhage particularly in young adults.

[Malignant peripheral nerve sheath tumor in the posterior mediastinum]. / Tumeur maligne de la gaine d'un nerf périphérique: une lésion rare du médiastin postérieur.

We report the case of a 52-year-old male patient who developed a malignant peripheral nerve sheath tumor (MPNST) localized in the posterior mediastinum. The diagnosis of this rare tumor is difficult because the clinical presentation of the benign or malignant types is often similar, i.e. elective pain and bone erosions. Similarly, radiological procedures do not always allow distinction between the two types. MNR and CT-scan are the first line procedures: they localize and characterize the lesions, and CT-scan can also be a guide for biopsies. Histological diagnosis is required, but diagnosis can be compromised by the heterogeneous nature of the tumor. Surgical treatment should be undertaken whenever possible. Survival was unusually long in our patient, more than 5 years after discovery of the MPNST. This type of sarcoma is often very aggressive with frequent development of local recurrences and metastases.

Control of breathing during exercise in patients with chronic airflow limitation with or without hypercapnia.

Twenty-four patients suffering from chronic obstructive pulmonary disease (COPD) exercised on a bicycle with a progressive increase in load (30 W/min) until dyspnea or exhaustion occurred. Seven subjects were CO2 retainers: PaCO2 greater than or equal to 45 mm Hg at rest and/or during exercise. Fifteen normal subjects were submitted to the same protocol. To make comparison possible, all the parameters studied were calculated at 60 watts. It was concluded that CO2 retention during exercise is not secondary to a decreased respiratory drive but mainly to a lesser increase in VE and to higher VD/VT ratios.

[Pulmonary embolism and pregnancy: report of a case; review of the literature]. / Embolie pulmonaire et grossesse: à propos d'une observation; revue de la littérature.

Pulmonary embolism occurring during pregnancy is a rare accident but that still brings about a high mother mortality; it seems to be five to six times more frequent during the pregnancy and the post-partum than for non-parturient women who don't take any estro-progestogens, pulmonary embolism would involve complications for 0.5/1000 pregnancies before delivery. As it presents a lot of diagnostic problems, it is under-estimated. The vascular radiological examinations expose the foetus or embryo to considerable radiation and to a risk of foetal hypothyroidism leading to backwardness. The lung perfusion scanning has the advantage of not injecting iodine but is not specific. Fortunately, some medical examinations such as plethysmography or Doppler echography are safe and can also guide the clinician. As far as therapy is concerned, intravenous heparin is the first intention treatment, it can be replaced subsequently by subcutaneous heparin (low molecular weight heparin). In case of heavy pulmonary embolism endangering the vital prognosis of the patient, in case of clinical or biological resistance to the medical treatment, it could be necessary to perform a pulmonary embolectomy with, if necessary, vena cava interruption with insertion of a mechanical filter.

P0.1 during exercise in normal subjects breathing mixtures of gas with varying densities.

BACKGROUND AND AIM: The aim of the study was to re-examine the occlusion pressure measured simultaneously in the mouth (P0.1) and the oesophagus (Poes.1) during exercise in normal subjects submitted to different gas mixtures. METHODS: 7 healthy men breathing random gas mixtures containing 21% oxygen with either by 79% helium (He-O2) or sulphur hexafluoride (SF6-O2) and room-air, were studied during a steady-state 90w exercise performed on a cyclo-ergometer. Ventilatory parameters were derived from the flow signal recorded by a pneumotachograph calibrated with the different gas mixtures. Three pressure transducers (mouth, eosophageal and gastric) were checked to have iso-time identical responses up to 4Hz. P0.1, Poes.1, deltaPoes (difference in oesophageal pressure between end-inspiratory and end-expiratory levels) and deltaPdi (variation of transdiaphragmatic pressure between end-inspiratory and end-expiratory levels) were measured. RESULTS: Hyperventilation associated with a similar deltaPoes/deltaPdi but a lower P0.1/deltaPdi ratio was observed in He-O2 breathing compared to SF6-O2 and air. Variable time delays between oesophageal and mouth pressures were observed during air and SF6-O2. Whatever the condition involved, no change was detected in the shape of the inspiratory pressure during the occlusion manoeuvres. CONCLUSIONS: He-O2 breathing probably induced a change in the shape of the pressure wave later on in the inspiratory phase, making P0.1 not representing the total inspiratory drive. On the contrary in air and SF6-O2 conditions, P0.1 seemed to remain a useful tool for looking at the output of the respiratory controller.

[Chronic hypercapnia at rest or exercise-induced and ventilatory patterns in patients suffering from chronic obstructive bronchopulmonary disease]. / Hypercapnie chronique de repos ou d'effort et mode ventilatoire chez les patients souffrant de maladie broncho-pulmonaire chronique obstructive.

The authors review the recent literature on hypercapnia at rest and on exertion in patients suffering from chronic airflow obstruction. At rest, the data in the literature has shown that for varying degrees of airflow obstruction, chronic hypercapnic patients show similar occlusion pressures to normocapnic patients. (The occlusion pressure is an index of the amplitude of neuro-muscular signals coming from the respiratory centre). However, their respiratory profile is characterised by a smaller tidal volume due to a reduction of the inspiratory time and often of a more rapid respiratory rate at a lower minute ventilation (VE). This pattern alone could explain CO2 retention by alveolar hypoventilation. On effort, various authors have shown that hypercapnic patients, or those becoming so during exercise, differ from normals by adopting a ventilatory pattern characterised by a reduction in ventilation linked to their airflow obstruction and a smaller tidal volume. The limited increase in tidal volume on effort is dependent on the duration of inspiration and the reduction of vital capacity and inspiratory capacity. As at rest, the two populations cannot be distinguished in terms of occlusion pressure.

[Subcutaneous emphysema in a borderline patient]. / Emphysème sous-cutané et troubles de la personnalité

This report concerns a 31-year-old woman. It is an intricate case including bilateral self-induced pneumoparotitis, cervical and facial subcutaneous emphysema and limited pneumomediastinum. Besides, this borderline patient simulated asthma attacks. The clinical picture was characteristic of Munchausen's syndrome with multiple hospitalisations in various hospitals, automutilations and intentional production of physical symptoms. The diagnosis and the treatment are discussed.

[Evaluation of diagnostic tests performance: the ROC curve]. / Evaluation des performances des tests diagnostiques: la courbe ROC.

Most of the diagnostic tests applied in clinic measure continuous or discrete ordinal variables and do not provide an "yes or no" response. Therefore, we can not assess tests nor compare them on the basis of a single pair of values of sensitivity and specificity. The ROC curve plots values of sensitivity against 1-specificity and allows evaluation of the discriminatory power of a test for all ranges of sensitivity and specificity when applied in two populations, one presenting the target disease and the other not. Evaluation of the discriminatory power or comparison of different tests are further deducted from the measure of the area under the curve. The discriminatory power of the test demonstrated, one has to determine the cutoff point on the ROC curve, that will provide the best information for clinical application.

[Decision analysis and initiation of an "empiric" therapy]. / Analyse decisionnelle et mise en oeuvre d'un traitement dit "d'epreuve".

For more than 25 years, quantitative approaches were applied to evaluate the outcome of diagnostic and therapeutic strategies. Decision analysis is but one quantitative approach that guides therapeutic decisions. It allows careful analysis of the therapeutic outcome taking into consideration the effects of medical treatment, quality of life and economic costs. The goal of this kind of approach is to choose the management with the greatest benefit for the patient through systematic and logic reduction of the diagnostic uncertainty. It uses a model represented by a decision tree that helps the clinician tot quantify the outcomes. Followed by sensitivity analysis, it may provide a robust basis for the final decision.

[Asthma and bronchial hyperreactivity. Current concepts]. / Asthme et hyperréactivité bronchique. Nouveaux concepts.

During the last decade much progress has been done in the understanding of the pathogenesis of asthma. The concept of a bronchospastic disease has been replaced by that of a chronic desquamating eosinophilic bronchitis. Bronchial inflammation is primarily responsible for airway hyperresponsiveness, the hallmark of asthma. An abnormality of a subtype of muscarinic receptors probably plays a permissive role.

[Pulmonary embolism: which diagnostic approach?]. / L'embolie pulmonaire: quelle démarche diagnostique?

The recent literature dealing with the diagnosis of pulmonary embolism is reviewed. Clinical signs, electrocardiogram and arterial blood gases analysis are not very helpful whereas a normal level of blood D-dimers makes the diagnosis of pulmonary embolism very unlikely. Lung scanning must be interpreted carefully in parallel with chest radiography. It is most useful if the pattern is either normal or of high probability. All intermediate scans are inconclusive and need a pulmonary arteriogram. Another option in patients with good cardiorespiratory reserve is the use of repeated non-invasive investigations of the lower limbs.

[The gold standard and optimalization of diagnostic choice: the pulmonary nodule and transthoracic pulmonary puncture-biopsy]. / Le "gold standard" et l'optimalisation du choix diagnostique: le nodule pulmonaire et la ponction-biopsie pulmonaire transthoracique.

In this review of the literature, it is emphasized that the published results about the transthoracic pulmonary needle biopsy (TPNB) cannot be readily evaluated due to the inconsistency of the reference tests, the methods and the investigated subjects. Gold-standards for evaluation of lung tumors have been described and are recalled. The limits of the TPNB are pointed out in the diagnosis of solitary pulmonary nodules and benign lesions. In a bayesian approach, it is shown that the TPNB is only useful in confirming an a-priori diagnosis of cancer.

Levothyroxine treatment and pregnancy outcome in women with subclinical hypothyroidism undergoing assisted reproduction technologies: systematic review and meta-analysis of RCTs.

BACKGROUND Previous meta-analyses of observational data indicate that pregnant women with subclinical hypothyroidism have an increased risk of adverse pregnancy outcome. Potential benefits of levothyroxine (LT4) supplementation remain unclear, and no systematic review or meta-analysis of trial findings is available in a setting of assisted reproduction technologies (ART). METHODS Relevant trials published until August 2012 were identified by searching MEDLINE, EMBASE, Web of Knowledge, the Cochrane Controlled Trials Register databases and bibliographies of retrieved publications without language restrictions. RESULTS From 630 articles retrieved, we included three trials with data on 220 patients. One of these three trials stated 'live delivery' as outcome. LT4 treatment resulted in a significantly higher delivery rate, with a pooled relative risk (RR) of 2.76 (95% confidence limits 1.20-6.44; P = 0.018; I(2) = 70%), a pooled absolute risk difference (ARD) of 36.3% (3.5-69.0%: P = 0.030) and a summary number needed to treat (NNT) of 3 (1-28) in favour of LT4 supplementation. LT4 treatment significantly lowered miscarriage rate with a pooled RR of 0.45 (0.24-0.82; P = 0.010; I(2) = 26%), a pooled ARD of -31.3% (-48.2 to -14.5%: P < 0.001) and a summary NNT of 3 (2-7) in favour of LT4 supplementation. LT4 treatment had no effect on clinical pregnancy (RR 1.75; 0.90-3.38; P = 0.098; I(2) = 82%). In an ART setting, no data are available on the effects of LT4 supplementation on premature delivery, arterial hypertension, placental abruption or pre-eclampsia. CONCLUSIONS Our meta-analyses provide evidence that LT4 supplementation should be recommended to improve clinical pregnancy outcome in women with subclinical hypothyroidism and/or thyroid autoimmunity undergoing ART. Further research is needed to determine pregnancy outcome after close monitoring of thyroid function to maintain thyroid-stimulating hormone and free T4 levels within the trimester-specific reference ranges for pregnancy.

Mycobacterium marinum infection causing extensive tissue destruction in a hypoxic COPD patient.

We report a skin Mycobacterium marinum infection presenting as wide ulcerative lesions of the arm (4 cm for the widest) in a hypoxic COPD patient who takes 4 mg methylprednisolone daily and higher doses during exacerbations. Diagnostic delay as well as glucocorticoid use could be responsible for the extension of the lesions. Clinical resolution occurred after three months of antibiotic therapy. Extensive ulcerative lesions are uncommon in Mycobacterium marinum infection in an immunocompetent host. This case emphasizes the potential and unusual harmful effect of long-term glucocorticoid therapy used in obstructive lung disease on the spread of Mycobacterium marinum infection.