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Objectives: Oxygen hood is largely used to deliver O₂ to newborn infants with respiratory failure in the northern region of France. The oxygen flow is set to obtain the target arterial blood oxygen saturation. Thus, O₂ flow delivers into the hood may be below the recommended gas flow of 6L/min. However, gas flow below 6L/min exposes to CO₂ rebreathing. The aim of this study was to evaluate the effect of various rates of gas flows on the values of partial pressure of CO₂ into the hood., Material and Methods: We measured CO₂ and O₂ partial pressure into hoods of two different volumes (4 and 10L) under two experimental bench test conditions. Protocol 1: gas flow was constant at 6L/min, while oxygen fraction varied from 0.21 to 1. Partial pressure of CO₂ and O₂ were recorded. Protocol 2: while O₂ fraction was kept constant, oxygen flow varied from 0.5 to 7L/min (by step of 0.5L/min). Partial pressure of CO₂ and O₂ were recorded., Results: Partial pressure of CO₂ increases proportionally to the decrease in the gas flow delivered into the hood, and reached 14 mmHg at gas flow of 0.5L/min., Conclusion: Risk of CO₂ rebreathing exists as soon as the gas is delivered into the hood at minimal flow rates below 6L/min., (2011 Elsevier Masson SAS. All rights reserved.)

Background: The provision of ambulatory oxygen in addition to a stationary oxygen supply has been suggested to increase adherence to long-term oxygen therapy (LTOT) and promote ambulation. The degree of adherence to ambulatory oxygen therapy and the determinants of adherence remain largely unknown., Methods: These were assessed in patients treated with LTOT (oxygen concentrator plus small oxygen cylinders with a demand oxygen delivery system [DODS]) in a tertiary care hospital supplied according to the Belgian criteria for LTOT refunding. Adherence to ambulatory oxygen was defined as mean use of ambulatory oxygen greater than 30 min/day. Patients' files were reviewed and a questionnaire was sent for assessing patients' view on the use of ambulatory oxygen., Results: Forty-six patients were included. Mean use of ambulatory oxygen was 40±36min/day. Twenty-three patients were adherent to ambulatory oxygen according to our definition. There was no difference between adherent and non-adherent patients regarding lung function or blood gases, nor was there any correlation between mean daily ambulatory oxygen use and any parameter. However, patients with MMRC 4 dyspnoea scale had a significantly lower use of ambulatory oxygen than patients with less severe dyspnoea (mean 33±24 vs 42±39min/day ; P=0.03) despite self reporting better adherence to LTOT., Conclusion: Adherence to ambulatory oxygen in this series of patients is quite low but at the higher end of data reported previously. Patients with MMRC 4 dyspnoea scale had a lower use of ambulatory oxygen despite reporting better adherence to LTOT. We could not identify any other predictive factors of adherence to ambulatory oxygen., (Copyright © 2011 SPLF. Published by Elsevier Masson SAS. All rights reserved.)

Introduction: There is doubt concerning the clinical effectiveness of portable oxygen concentrators with a control valve (PCDV) and their appreciation by patients. Objectives. To compare the effectiveness and appreciation of oxygen therapy by PCDV and liquid oxygen by continuous f low (O(2)Liq)., Methods: Nineteen patients with COPD were randomised to receive PCDV or O(2)Liq at rest and during a 6 minute walk test (6MWT). For each mechanism they assessed, by visual analogue scales, the convenience and portability, the noise, and the discomfort of the nasal oxygen delivery., Results: The 6MW distance was 315 ± 120 m with PCDV and 325 ± 114 m with O(2)Liq (P>0.05). Dyspnoea and the desaturation induced by the 6MWT were identical with both systems (P>0.05). The time spent with a SaO(2)<90 % was 289 ± 69 s with PCDV and 242 ± 130 s with O(2)Liq (P=0.08). PCDV was noisier than O(2)Liq (P<0.05); there was no difference in convenience and portability or in nasal discomfort., Conclusion: The PCDV model that we tested was equally effective to O(2)Liq. However, the prescription of this type of system is a matter of personal choice., (Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.)

Most of the contemporary guidelines on newborn resuscitation are based on experience but lack scientific evidence. The use of 100% oxygen is one of the more evident. Today, these practices are questioned, particularly for the resuscitation of moderately depressed full-term or near-term newborns. Results of recent meta-analysis of trials that compared ventilation with room air versus pure oxygen at birth suggest current practices should be revisited. On the basis of these data, air can be the initial gas to use for these babies. Large-scale trials, including preterm and cause and/or severity of initial asphyxia, must now be undertaken before the publication of new guidelines for these populations.

The main indication of LTO is COPD with chronic respiratory failure, where it improves life expectancy. By extension, LTO may be proposed to other etiologies of CRF with chronic documented hypoxemia. Daily duration is at least 15H per day. Non invasive ventilation (NIV) represents facial or nasal ventilation. Consensus indications of NIV are restrictive pulmonary diseases (chest wall and /or parenchmal sequelae, neuromuscular diseases, or obesity hypoventilation syndrome) Real role of NIV in log-term management of COPD remains controversial.

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.

The different possibilities of oxygen delivery cylinders with integrated pressure regulator have taken a preponderant place since their arrival in 1995 in both health establishments and home care. This is mainly due to their safe and easy use. These cylinders are made of a light material (aluminium alloy coated with synthetic polymers) and have obtained, as the other medicinal oxygen forms, a French marketing authorization in 1997. After 7 years of availability in hospitals, the author provides a comparison between the hospital market and a critical assessment of announced advantages with respect in notified cases of vigilance. For the smaller capacities (particularly the 5 litre cylinders) new cylinders have substituted the classical cylinders, which oblige to connect an independent pressure regulator. Each year this last technology causes a lot of failures, sometimes serious. French manufacturers are aware of this development; meanwhile it remains limited to other EU countries. The offer is generally satisfying, similar upon safety and advantages (weight, residual pressure valve, and easiness of handling) with a large flow choice and maintenance under the responsibility of the manufacturer. The choice of these cylinders for hospital is particularly notified and has to be encouraged because avoiding risk of accidents due to the erratic maintenance of pressure regulators fitted with usual cylinders where it is not accomplished by technicians duly educated and qualified for this purpose.

Introduction: CPAP (Continuous Positive Airway Pressure) is one of the treatments of the cardiogenic acute pulmonary edema (cAPE). Among the out-of-hospital used devices, Boussignac CPAP (Vygon) shows a good technical usability, but no analysis of delivered FIO2 is available., Objective: To measure the FIO2 delivered to patient, using Boussignac CPAP with an input of 100 vol % oxygen. Type of study. - Measurement in a laboratory testing., Material and Method: Measurement of delivered FIO2 in a three parameters environment: expiratory positive airway pressure (EPAP), respiratory rate (RR) and required oxygen flow (ROF). Laboratory test: 100 vol % oxygen input, with a ball-type flow regulator for oxygen 0-30 l x min(-1) (Mediline), Boussignac CPAP valve with manometer (Vygon), Michigan test lung, ventilator César (Taema), oxygen analysis (Servomex) with paramagnetic sensor, with a response time < 10 s, pneumotachographe (Fleisch v 2)., Results: Under 10 cmH2O EPAP, the required oxygen flow is < or = 30 l x min(-1). Measured FIO2 ranges from 70 to 100 vol %, for a volume per minute < or = 15 l x min(-1) except for a EPAP at 2.5 cmH2O with a rate = 10 c min(-1) and a tidal volume (VT) at 1500 ml where the measured FIO2 is 60 vol %. For a volume per minute > 15 l x min(-1) and < 20 l x min(-1), measured FIO2 ranges from 59 to 83 vol % depending on the variations of RR and VT., Conclusion: Boussignac CPAP with 100 vol % oxygen input, delivers high levels of FIO2, especially for volume per minute values usually met in cAPE. The needed oxygen flow is lower than what is usually required by other CPAP flow generators using the venturi effect that may be used in out-of-hospital medical care.

The obstetrical population is prone to difficult or failed intubation. Control of the airway is complicated by several factors specific to obstetric anesthesia; time of apnea is short due to a reduced functional residual capacity, pregnancy-induced hypertension and obesity are relatively frequent; anesthetist's skill can also be mentioned. The best approach to this problem lies in its prevention, using epidural analgesia as soon as possible. Furthermore, the number of difficult intubations can be considerably reduced by a thorough pre-anesthetic examine. Each anesthetist must keep an algorithm in mind, should a difficult or failed intubation in obstetrical patient. Whichever method is used (ventilation through a facial mask or laryngeal mask, transtracheal oxygenation), the anesthetist must never forget that the first priority is always the safety of the mother.

Bronchial fibrescopy in intensive therapy patients raises the problem of oxygenation during the procedure. The Fibroxy mask allows fibrescopy with simultaneous O2 administration and manual or mechanical ventilation. This study, which included ten patients, assessed the benefits of this device. During fibrescopy, the heart rate, the mean arterial blood pressure, and the arterial oxygen saturation (SpO2) remained unchanged and only one short episode of desaturation occurred. The satisfaction index was high. However, this mask did not fit closely to the patient's face, and an additional assistant was required for efficient ventilation. Moreover, end-tidal CO2 could not be monitored satisfactorily. After some improvements, this device seems to be of value for bronchial fibrescopy in intensive therapy unit.

The incidence of chronic respiratory failure is underestimated in Martinique. The aim of our retrospective study was to determine local particularities. Between December 1991 and December 1995, 128 patients (55% men, mean age 60 years, range 18-89 years) were hospitalized in our pneumology unit to receive a respiratory device (oxygen concentrator, respirator, continuous positive pressure generator). The high percentage of continuous positive pressure generators contrasted with the low number of oxygen concentrators prescribed indicating that obstructive disease is relatively less common due to the absence of widespread smoking habits. Sleep apnea syndrome (SAS) was particularly frequent in women (44% of the SAS patients). 10% of the SAS patients had perturbed blood gases unexplained by an associated bronchopathy. SAS in obese, hypertensive, diabetic women in Martinique is a public health problem and should be assessed by a prospective study. We observed that home care was particularly difficult for the most severely diseased patients, especially those with a tracheotomy, due to the lack of a management structure.

In addition to anecdotal techniques originating from Galen's reasoning, the methods for the treatment of nearly-drowned persons from the XVIIIth century to the first quater of the XIXth century, are surprising as they still include the artificial internal ventilation techniques of today. Nevertheless for more than one century, these techniques were abandoned. External manual methods generating a forced expiration were preferred until 1958, when Peter Safar and coworkers demonstrated the value of mouth-to-mouth ventilation in comparison with manual methods. This eclipse finds its origin mainly in Leroy d'Etiolles's 'alarming' dissertation produced in 1827, underlining the pleuro-pulmonary risks of endotracheal insufflation and recommending the external manual methods, considered as being easy to use by everybody, without risk, and however improperly given as being efficient. As a result, the European philantropic societies abandoned bellows and positive pressure ventilation in their official resuscitation scheme for the nearly-drowned and asphyxiated.

This prospective study assessed, in 10 conscious patients without a history of chronic respiratory disease, the feasibility of mechanical pressure support ventilation with PEEP by face mask for the treatment of acute respiratory failure without hypercapnia. Pressure support level was determined to obtain a VT of 5 to 10 mL.kg-1 and a decrease of respiratory rate of more than 20%. FIO2 and PEEP levels were determined to obtain a SpO2 > 92% and a PaO2 > 70 mmHg. The efficiency of the technique was assessed through the time course of respiratory rate, PaO2, PaCO2 and SaO2. The technique was efficient in all patients and tracheal intubation was not required. During face mask ventilation, a significant decrease in respiratory rate and an increase in PaO2 and SaO2 were observed. Pressure support ventilation with PEEP by face mask is an efficient technique for the treatment of acute non hypercapnic respiratory failure in conscious and cooperative patients.

Long-term domiciliary oxygen therapy in patients with chronic respiratory failure significantly improves both survival and quality of life. These therapeutic objetives are only achieved by daily oxygen therapy of more than 15 hours. For a period of 3 months, we have prospectively measured the duration of oxygen therapy in 930 patients with chronic airflow obstruction. This is carried out by reading the meters on the oxygen concentrators, or for liquid oxygen by checking the weight of the cylinders at each delivery, making allowances for the flow rate and also for natural loss from evaporation. The instructions for oxygen therapy and the true therapy of the patient were then gathered using a questionnaire. The practitioners were questioned on the prescription for oxygen therapy which had been made for each patient, and more generally on their usual criteria for prescribing long-term oxygen therapy. The patients (82% male) were aged between 67 +/- 8 years, and were on domiciliary oxygen therapy 36 +/- 24 months, with hypoxaemia (PaO2 = 56 +/- 9 mmHg), hypercapnea (PaCO = 47 +/- 8 mmHG) and suffering from airflow obstruction (FEV1/VC = 42 +/- 14%). The duration of prescribed oxygen therapy was on average 16 +/- 3 hours. The mean duration of oxygen therapy achieved was 14.5 +/- 5 hours, but only 45% of the patients (419/930) managed daily oxygen therapy superior of equal to 15 hours and were categorised as compliant.(ABSTRACT TRUNCATED AT 250 WORDS)

In France, the presence of an emergency oxygen cylinder as part of every the anaesthetic machine is not made compulsory by an official regulation. This article provides arguments in favour of such a presence, as recommended by the French Society of Anaesthesia and Intensive care (SFAR).

Long-term oxygen therapy (LTOT) has a significant effect on the survival of patients with chronic obstructive bronchitis and/or emphysema (COPD). The rationale for this therapy is based on prevention of the increase in pulmonary arterial tension resulting from chronic hypoxia. There are several problems in the application of this treatment to individual patients, and they are reviewed in this paper. Indication for LTOT depends on precise criteria. Information to the patients and to the medical community is essential for the success of this therapy.

Long-term oxygen therapy improves the life expectancy of hypoxaemic patients with chronic obstructive pulmonary disease (COPD), provided the hypoxaemia is sufficiently pronounced under stable conditions (PaO2 less than 55 mmHg) and oxygen is given for more than 16 out of 24 hours. By extension, the same indications are applicable to hypoxaemia due to other causes (diffuse fibrosis, pneumoconiosis, cystic fibrosis, etc.). Long-term oxygen therapy improves the patients' quality of life and also has favourable effects on oxygen transport, neuropsychological status, polycythaemia and pulmonary hypertension. It is usually delivered by means of O2 extractors, to which may be added small flasks of O2 gas for walking and moving about. Liquid O2 is a good solution for subjects who are motivated and are obliged to do a great deal of walking. The O2 flow rate administered must be such that it rises the PaO2 level above 60 mmHg. Oxygen therapy is only a symptomatic treatment and cannot replace other types of therapy, such as bronchodilators, physiotherapy, etc. It gives satisfactory results but it has not transformed the prognosis of severe hypoxaemic COPD.

The saturation of oxygen (SaO2) using oxygen therapy with an oxygen saving system, Optimox (CFPO) or COS 5 (Puritan, Bennett) has been compared to the SaO2 using continuous oxygen therapy. The oxygen output using the oxygen saving system was regulated in such a way as to be equivalent to the oxygen flow without the economiser. Three situations were studied: the day, the night and during effort. Ninety four patients (84 men and 10 women), aged 65.3 +/- 9.7), who were hypoxaemic (SaO2: 84.5 +/- 6.4%) coming from twelve pneumology units were included in the study. The percentage of time spent above SaO2 (T greater than 90) was used to judge the criteria of the efficacy of the oxygen therapy. T greater than 90 without (SSECO) and with the oxygen saving system (AVECO) were compared in each subject. T greater than 90 AVECO was below T greater than 90 SSECO in 52% of patients and was greater in 23% of subjects. The nasal, auditory and respiratory comfort was good whatever the period of examination for more than half of the subjects. In conclusion for an equivalent oxygen flow the addition of an oxygen saving device significantly alters the quality of diurnal and nocturnal oxygen therapy in one patient out of two.

The emergency tracheotomy is indicated when there is a respiratory distress caused by the complete obstruction of the upper airway and when the etiological and symptomatic treatments have failed. However, it is not an easy procedure for a non specialist outside the hospital environment. The translaryngeal stem maintains a minimal ventilation while waiting for the emergency medical unit.

The authors belong to Medical Urgency Service of the Firemen Brigade of Paris. They detailed the indispensable material for cardio-respiratory reanimation that they use during their interventions.

The measurement of transcutaneous PtcO2 in eight normal adults prove a comparable efficacy of 50 l.min-1 O2 through facial "small mask" (61.5 kPa; 463 mmHg) and 20 l.min-1 O2 through head tent (65.1 kPa; 490 mmHg). First procedure, inexpensive, is very simple to use.

Different sources of oxygen can be used in patient's homes: gas cylinders, portable liquid oxygen or a concentrator. The choice regarding source is related to the aims (nocturnal oxygenation, oxygen for rehabilitation), the length of daily treatment and the desire for patient autonomy. The selection flow rate during the day, the night and/or during exercise depends essentially on the physiological consequences of oxygen administration, planned in a precise fashion for periods not exceeding 24-48 h. Three types of tests may be retained: 1. A 30 minute day test, 2. A prolonged night study, 3. A polygraphic study. First, the short, resting, day-time, 30 minutes test measuring output from variations of PaO2, PaCO2 and pH before and after 30 minutes of inhalation; simultaneous measurements of PAP (but haemodynamic variations during the test do not carry long term predictive values). Secondly, long term studies at night: these trials may either include simple measurements, such as oxygen saturation with an ear oxymeter or more complex polygraphic measurements. Nowadays for the simple measurements with ear oxymetry, one night on ambient air and one on oxygen seems adequate in providing vital information regarding nocturnal hypoxia and its correction. Thirdly, respiratory polygraphs which provide better information on the mechanism of hypoxia but are much more difficult to use in daily practice. These polygraph studies should be reserved only for high risk sufferers, the obese and snorers. Among the exercise tests necessary to confirm that the benefit of oxygen therapy outweighs the disadvantage of carrying a portable oxygen system, is the Mac Gavin test (distance walked in 12 minutes) completed by doing blood gases to assess the indications and the efficacy of the portable system.

Different ways of using oxygen enrichers have been studied. First, the performances of two different devices were tested: the results were very similar to the constructors' previsions. Second, oxygen concentrations in venturi masks connected to enrichers were measured with a mass spectrometer. The authors suggest to adjust the flow delivered by enrichers at 3 liters/min for any type of venturi mask. Pharyngeal oxygen concentration curves show the reliability of masks connected to enrichers compared to other modes of administration (nasal cannulae, nasal catheter).

Oxygen dilution devices (Venturi 3 and 4) with Multi-VentTM mask, using an oxygen flow rate of 6 1/min, are insufficient when subjects' ventilation is increased : inspired oxygen concentration is lower than predicted. This can be detrimental to patients who could benefit by oxygenotherapy during exercise.