Automatic oxygen administration and weaning in patients following mechanical ventilation.

PURPOSE: To evaluate efficacy of FreeO2 device in oxygen weaning of patients after being liberated from mechanical ventilation (MV). METHODS: Prospective crossover cohort study in patients admitted to ICU and after MV weaning. FreeO2 curves were recorded during constant flow and FreeO2 modes. Oxygenation parameters and O2 consumption were assessed. RESULTS: Fifty one records were obtained in 51 patients (median age, 62 years, 54.9% had COPD, admission for acute respiratory failure in 96%). NIV was used initially in 68.6%. For a median records duration of 2.04 h, the time spent within target SpO2 range was significantly higher with FreeO2 mode compared to constant O2 flow mode [86.92% (77.11-92.39) vs 43.17% (5.08-75.37); p < 0.001]. Time with hyperoxia was lower with FreeO2 mode: 8.68% (2.96-15.59) vs 38.28% (2.02-86.34). Times with hypoxaemia, and with severe desaturation, were similar. At the end of FreeO2 mode, O2 flow was lower than 1 l/min in 28 patients (54.9%), with a median of 0.99 l/min. CONCLUSIONS: For the purpose of oxygen weaning in patients recovering from MV, automatic O2 titration with FreeO2 was associated with a substantial reduction in O2 delivery and better oxygenation parameters in comparison with constant O2 flow.

Compliance with the European trauma guidelines: An observational single centre study.

OBJECTIVES: The European trauma guidelines were developed to assist clinicians in the early phase of trauma management to diagnose and treat coagulopathy and bleeding. This study aimed to determine compliance with these European trauma guidelines in a French referral trauma centre. METHODS: Medical charts of trauma patients with an injury severity score≥16 admitted between January 2013 and December 2014 were reviewed. Compliance with 21 recommendations in the first 24-hours of patient management was assessed. RESULTS: There were 145 patients with median ISS of 34 [IQR 25-41]. A good level of compliance (i.e. applied in≥80% of patients) was identified for nine recommendations, inconsistent compliance (i.e. applied in 50 to 79% of patients) for six recommendations, including fibrinogen levels at hospital admission and achievement of a target mean arterial blood pressure (MAP)>80mmHg in patients with major bleeding and TBI (55.5%), and poor compliance (i.e. applied in<50% of patients) for another six recommendations. Poorly applied recommendations included early measurement of lactate or base deficit (32%), early administration of tranexamic acid (18%), and achievement of normocapnia in patients with TBI undergoing invasive ventilation (3%). CONCLUSIONS: In a referral trauma centre, nine of the 21 evaluable recommendations in the European trauma guidelines were applied in≥80% of patients. Early diagnosis and treatment of trauma-related coagulopathy was identified as an area for significant practice improvement. In patients with TBI, efforts should be made to achieve the targeted MAP and to maintain normocapnia.

[Indications and practical issues concerning oxygen therapy]. / Intérêts et modalités pratiques de mise en route d'une oxygénothérapie.

INTRODUCTION: The initiation of oxygen therapy for acute or chronic respiratory failure is a common medical intervention, both for hospital in-patients and in out-of-hospital emergency settings. Oxygen therapy is also frequently initiated by paramedics or nurses, without any initial medical prescription, in acutely ill patients. STATE OF THE ART/PERSPECTIVES: It is important to remember that oxygen is a pharmaceutical drug, and its prescription should therefore be considered within treatment guidelines. Two main pathological situations may be encountered: tissue hypoxia and acute/chronic hypoxemia. CONCLUSION: Physicians should be aware of the clinical signs that may indicate the presence of hypoxia and the pathological situations that may lead to hypoxemia. They must also be aware of the potential complications, in particular CO(2) retention in patients with chronic type II respiratory failure as well as the overall indications, and practical issues concerning oxygen therapy.

Biphasic-flow induced ventilation allows simultaneous ventilation in several animals, using a single multiple output ventilator--a preliminary report.

Biphasic-flow induced ventilation (BiFIV) is a variable time-cycled tracheal gas insufflation mode, using a specific multiluminal endotracheal tube. Some recent studies have reported efficiency of this new ventilatory mode in experimental in vitro and in vivo settings. We hypothesized that this ventilatory mode could be able to deliver simultaneous efficient ventilation for several animals, using a single ventilator prototype. The study was performed in three groups of three domestic pigs with a normal lung compliance. Each pig was initially anaesthetized, intubated with the specific endotracheal tube, and ventilated with a conventional ventilatory device. The animals were then simultaneously ventilated under BiFIV, using a single ventilator prototype, for each group of three animals. Physiological parameters and arterial blood gases were recorded at each study phase. All animals but one survived the experiment. We did not observe any significant differences in arterial gas exchange, under both ventilatory modes. Oxygenation was as efficient for each three animals ventilated under BiFIV, using a single ventilator device, as under conventional ventilation, using three separate ventilators (PaO2 = 112+/-17 mmHg under conventional ventilation versus 115+/-16 mmHg under BiFIV). In conclusion, variable time-cycled tracheal gas insufflation may allow an efficient multiple ventilation on several animals, using a single multiple output ventilatory device, in a normal lung animal model. If validated on subsequent pathological models, it could thus be interesting in laboratory and/or mass casualty situations.

Helium-oxygen breathing in the early emergency care of acute severe asthma: a randomized pilot study.

The aim of this study was to establish whether a clinical trial, comparing helium-oxygen (HeO2) breathing to standard therapy, would be feasible during the out-of-hospital care of adult patients with severe asthma. Although the primary outcome in a definitive trial will be a decrease in morbidity, the present study primarily examined: (1) if the strategy could be successfully implemented in emergency ambulatory units; (2) if the research staff could enroll enough patients, given the resources. Nine patients were included in the conventional treatment group, and seven patients in the HeO2 group. Patients randomized to the HeO2 group breathed the mixture for a 12-hour period. Clinical and biological parameters improved for all patients. There was no trend towards a HeO2 benefit, whether during the initial out-of-hospital nor the ICU care. No patient was intubated within the study period. HeO2 breathing was considered to be simple to initiate, and no side effects were reported. In conclusion, while HeO2 breathing is easy to apply, even in the out-of-hospital setting, the few enrolled patients did not appear to benefit from this treatment. Regarding our low inclusion rate and the lack of positive effect trend, we believe that a large definitive trial will be difficult to initiate in such an emergency care setting.

[Spontaneous ventilation in positive expiratory pressure in cardiogenic pulmonary edema. Prospective study]. / Ventilation spontanée en pression expiratoire positive au cours de l'oedème pulmonaire cardiogénique. Etude prospective.

New equipment facilitating the use of spontaneous ventilation with positive expiratory pressure (PEP) has become available in France since January 1996. This technique was applied in 38 patients with severe cardiogenic pulmonary oedema and persistent respiratory distress despite high flow classical oxygen therapy and standard treatment. After 1 hour of ventilation with a flow of 220 l/min of 100% oxygen with an average PEP of 7.7 cm H20, a significant improvement of clinical (heart and respiratory rate) and biological parameters (arterial gases) was observed. There were no side effects. Four patients died during the hospital period and only 1 was intubated. Spontaneous ventilation with PEP is a simple technique for coronary care units and, compared with conventional oxygen therapy, it rapidly improves arterial oxygenation, reduces respiratory work and improves conditions of cardiac load. Acute severe cardiogenic pulmonary oedema seems to be an indication of choice, especially in the elderly, where it may help avoid an often controversial intubation.

[Revision of the 3rd Consensus Conference in Intensive Care and Emergency Medicine in 1988: management of acute asthmatic crisis in adults and chidren (excluding infants)]. / Révision de la troisième conférence de consensus en réanimation et médecine d'Urgence de 1988: prise en charge des crises d'asthme aiguës graves de l'adulte et de l'enfant (à l'exclusion du nourrisson).

Experts designated by the "référentiels" committee of the SRLF analyzed the numerous articles published after the French consensus conference on the severe acute asthma of 1988. From their work, a revision of this consensus conference has been performed. The pediatric specificity has been added in this revision. There is no severity score able to predict the severity of acute asthma on admission. In every case, the nebulization of beta-2 agonists represents the priority treatment. The nebulization of anticholinergic associated with the beta-2 agonists induces a moderate additional effect. In the absence of response to nebulizations, the usefulness of the beta-2 agonists associated intravenous. Administration is not demonstrated. Corticosteroids should be administered using a 1 to 2 mg per kg dosage, but their efficacy is delayed. In adult patients, aminophylline should not be prescribe, but it is still used by some pediatricians. Other associated treatments (adrenaline, magnesium sulfate, helium-oxygen mixture) did not demonstrate their efficacy as adjunctive therapies. The therapeutic response should be evaluated using the peak flow determination.

[Spontaneous positive end-expiratory pressure ventilation in elderly patients with cardiogenic pulmonary edema. Assessment in an emergency admissions unit]. / Ventilation spontanée en pression expiratoire positive au cours de l'oedème pulmonaire cardiogénique de la personne âgée. Etude dans un service d'accueil et d'urgence.

OBJECTIVES: Intubation and ventilatory assistance are often required in patients presenting severe hypoxemic respiratory distress, but may be contraindicated in elderly subjects due to an underlying condition. The aim of this study was to assess the feasibility, acceptability and contribution of early assistance with spontaneous positive end-expiratory pressure ventilation for elderly subjects admitted to an emergency unit for acute respiratory distress due to cardiogenic pulmonary edema. PATIENTS AND METHODS: In our emergency admission unit, all patients with life-threatening hypoxemic respiratory distress are initially assisted with noninvasive spontaneous positive end-expiratory pressure ventilation using a standardized commercial device. We retrospectively analyzed the the files of all patients aged over 70 years who were treated with this standard protocol for cardiogenic pulmonary edema from April 1996 through September 1997. RESULTS: During the study period, 36 patients aged over 70 years required ventilatory assistance according to the standard protocol. Intubation was not reasonable in most of the patients (n = 30). After 1 hour of ventilation, none of the patients developed clinical signs of life-threatening distress. Blood gases demonstrated improved oxygenation (AEPO2 = +184.9 +/- 105.4 mmHg; p < 0.000001). Thirty-two patients were considered to be cured (88.9%) and were discharged; the cardiovascular condition was fatal in 4 patients (11.1%). CONCLUSION: The rapid improvement in clinical signs and blood gases as well as the final outcome suggests that early assistance with spontaneous positive end-expiratory pressure ventilation is warranted at admission for elderly patients with respiratory distress due to cardiogenic pulmonary edema. Compared with a control group of hospitalized patients cared for during the preceding year and who were not treated with the standard protocol, we also demonstrated a clear improvement in mortality (11% versus 20%).

[Association of sarcoidosis and autoimmune thyroiditis]. / Association sarcoïdose et thyroïdite auto-immune.

The thyroid gland involvement in sarcoidosis is rare but not exceptional. Usually there is little or no clinical expression although hyperthyroidism may be present. The granulomatous infiltration of the thyroid gland cannot be responsible for all the abnormalities observed. In certain cases, there is undoubtedly an autoimmune disease. We report a case of concomitant discovery of sarcoidosis and Hashimoto's thyroiditis. Despite their relative frequency, there could be a relationship between these two pathologies, especially in light of their similar pathophysiology.

[Use of helium-oxygen gas mixtures in acute obstructive respiratory insufficiencies]. / Utilisation des mélanges gazeux hélium-oxygène au cours des insuffisances respiratoires aiguës obstructives.

Therapeutic use of helium has been described since 1930. Its main action is to reduce bronchial resistances and consequently overall respiratory work. Helium is substituted for nitrogen. The effects of inhaling a helium-oxygen mixture result exclusively from the physicochemical properties of helium: very low density, high kinetic viscosity. With the advent of selective bronchodilators, use of helium was rapidly abandoned until recently with new interest for the treatment of severe acute asthma. We review the literature on the physical properties of helium-oxygen mixtures and propose an analysis of their therapeutic use in severe acute asthma as well as other indications such as acute episodes of obstructive bronchopneumonia and obstruction of the upper airways. Due to the non-invasive nature of this technique, its easy use with spontaneous ventilation and the large body of theoretical data emphasizing its adaptation for therapeutic use, helium-oxygen gas mixtures offer an important therapeutic option for treating severe diseases with poor prognosis. A multicentric national study is under way to validate its use early by emergency ambulatory units for the treatment of severe acute asthma.

Impact of the humidification device on intubation rate during noninvasive ventilation with ICU ventilators: results of a multicenter randomized controlled trial.

PURPOSE: The use of heat and moisture exchangers (HME) during noninvasive ventilation (NIV) can increase the work of breathing, decrease alveolar ventilation, and deliver less humidity in comparison with heated humidifiers (HH). We tested the hypothesis that the use of HH during NIV with ICU ventilators for patients with acute respiratory failure would decrease the rate of intubation (primary endpoint) as compared with HME. METHODS: We conducted a multicenter randomized controlled study in 15 centers. After stratification by center and type of respiratory failure (hypoxemic or hypercapnic), eligible patients were randomized to receive NIV with HH or HME. RESULTS: Of the 247 patients included, 128 patients were allocated to the HME group and 119 to the HH group. Patients were comparable at baseline. The intubation rate was not significantly different: 29.7% in the HME group and 36.9% in the HH group (p = 0.28). PaCO2 did not significantly differ between the two arms, even in the subgroup of hypercapnic patients. No significant difference was observed for NIV duration, ICU and hospital LOS, or ICU mortality (HME 14.1 vs. HH 21.5%, p = 0.18). CONCLUSIONS: In this study, the short-term physiological benefits of HH in comparison with HME during NIV with ICU ventilators were not observed, and no difference in intubation rate was found. The physiologic effects may have been obscured by leaks or other important factors in the clinical settings. This study does not support the recent recommendation favoring the use of HH during NIV with ICU ventilators.

The semi-seated position slightly reduces the effort to breathe during difficult weaning.

PURPOSE: The influence of posture on breathing effort in patients with difficult weaning is unknown. We hypothesized that posture could modulate the breathing effort in difficult-to-wean patients. METHODS: A prospective, crossover, physiologic study was performed in 24 intubated patients breathing with pressure support who had already failed a spontaneous breathing trial or an extubation episode. Their median duration of mechanical ventilation before measurements was 25 days. Breathing pattern, occlusion pressure (P (0.1)), intrinsic PEEP (PEEP(i)), and inspiratory muscle effort evaluated by the pressure-time product of the respiratory muscles and the work of breathing were measured during three postures: the seated position in bed (90°LD), simulating the position in a chair, the semi-seated (45°), and the supine (0°) positions consecutively applied in a random order. A comfort score was obtained in 17 cooperative patients. The influence of position on chest wall compliance was measured in another group of 11 sedated patients. RESULTS: The 45° position was associated with the lowest levels of effort (p ≤ 0.01) and occlusion pressure (p < 0.05), and tended to be more often comfortable. Respiratory effort was the lowest at 45° in 18/24 patients. PEEP(i) and PEEP(i)-related work were slightly higher in the supine position (p ≤ 0.01), whereas respiratory effort, heart rate, and P (0.1) values were increased in the seated position (p < 0.05). CONCLUSION: A 45° position helps to unload the respiratory muscles, moderately reduces PEEP(i), and is often considered as comfortable. The semi-seated position may help the weaning process in ventilator-dependent patients.

[Current trends in plasma transfusion for patients with severe hemorrhage]. / Plasma thérapeutique dans les hémorragies sévères.

Recent changes in plasma transfusion practices for severe hemorrhage are largely related to the recognition of an early endogenous coagulopathy associated with traumatic injury. Observational and mostly retrospective data suggest improved survival rates with high-dose plasma therapy, up to a 1:1 ratio of fresh frozen plasma to packed red blood cells, but the quality of evidence is limited. Putting it into practice raises many issues (early identification of patients at risk of massive bleeding, extrapolation to non-trauma settings, alternative or adjunctive treatments, among others) that are discussed in this brief review.