[Comparison of the aerosol produced by electronic cigarettes with conventional cigarettes and the shisha]

In previous studies of the smoke from regular cigarettes and water pipes, we measured aerosol particle sizes in three streams; S1, inhaled by the smoker, S2, released by the device itself and S3, exhaled by the smoker. We used an electrostatic low-pressure impactor (ELPI), giving particle size distributions in real time and calculated median diameters, D50, and dispersion (σg). This allowed us to predict airway deposition. In addition, the aerosol particle half-life in the air was used as a measure of the risk to others from passive smoking. With the same equipment, we measured the particle sizes and persistence in air of the liquid aerosol generated by e-cigarettes (Cigarettec®) containing water, propylene glycol and flavorings with or without nicotine. Aerosol generation was triggered by a syringe or by the inspiration of volunteer smokers. The D50 data obtained in S1, were 0.65 μm with nicotine and 0.60 μm without nicotine. Deposition in the airways could then be calculated: 26% of the total would deposit, of which 14% would reach the alveoli. These data are close to those found with regular cigarettes. For S3, D50 data were 0.34 μm and 0.29 μm with or without nicotine. The half-life in air of the S3 stream was 11 seconds due to a rapid evaporation. The-e-cigarette aerosol, as measured here, is made of particles bigger than those of cigarette and water pipe aerosols. Their deposition in the lung depends on their fate in the airways, which is unknown. Contrary to tobacco smoke, which has a half-life in air of 19 to 20 minutes, the risk of passive "smoking" exposure from e-cigarettes is modest.

[A survey of nebulization practices in France conducted in 2004 by the GAT]

METHODS

A questionnaire was sent to 50 000 general practicioners (GP) and specialists.

RESULTS

4,898 physicians (9.4%) responded, including 59.1% GP, 16.9% pneumologists, 13% pediatricians and about 10% other specialists, ENT, allergologists, and intensivists. The main reason for pneumologists to prescribe nebulization was the efficiency on long term of approved drugs. GP prescribe nebulization for its local effects, using unapproved drugs, on short periods of time, especially in COPD, asthma, bronchitis and tracheitis/laryningitis. Although pneumologists have been trained during their fellowship and do not ask for further education, MG have learned by their own experience and are asking for further education.

CONCLUSION

This study should help to develop teaching programs on nebulization with the aim to optimize its practice.

N.U.A.G.E.S: A survey of nebulisation practice in France with regard to ERS guidelines

A survey of nebulisation practice in France was conducted under the aegis of the French respiratory society in 2004.

METHODS

Analysis of a questionnaire was obtained from 3674 physicians.

RESULTS

A total of 2439 physicians were general practitioners (GPs), 698 were chest physicians, and 537 paediatricians. The main reasons to use nebulisation are (1) for chest physicians efficacy in treating various pathologies with long-term administration (1 wk to 1 month) of approved drugs, and (2) for GP's local action properties. While chest physicians learned about nebulisation during their university training and do not ask for additional information, GPs learned by practical experience or from colleagues and ask for further information.

CONCLUSION

This study will help to develop targeted educational programmes on nebulisation practice.

[Particle size in the smoke produced by six different types of cigarette]

INTRODUCTION

For several decades a more peripheral distribution of the broncho-pulmonary pathologies related to tobacco has been observed.

METHODS

The aim of this study is to examine whether changes in the particle size of cigarette smoke as the result of new manufacturing technologies could play a part in the observed epidemiologic changes through a more distal disposition of smoke particles in the airways. Using a smoking machine and a low pressure electrostatic impactor we measured the particle size of the smoke from six different types of cigarette, representing old and new manufacturing techniques. The effect of a filter was assessed by a size analyser measuring the electrical mobility of the particles.

RESULTS

The results show a difference in particle size between the primary smoke inhaled by the smoker, S1 (0.27 +/- 0.03 microm.) and the secondary smoke, S2 inhaled by passive smokers (0.09 +/- 0.01 microm). There is no difference in particle size between the 6 different types of cigarette. Filters dilute the smoke without altering particle size.

CONCLUSION

The recent alterations in the distribution of tobacco related pathologies cannot be explained by changes in particle size in cigarette smoke. The explanation has to sought elsewhere.

Validation of laser diffraction method as a substitute for cascade impaction in the European Project for a Nebulizer Standard

The project for a European standard testing procedure to characterize nebulizers in terms of particle size distribution has been based on using the Andersen-Marple personal cascade impactor model 298 (A-MPCI) with a sodium fluoride reference solution. In the present study methods based on laser diffraction (Mastersizer-X) and time-of-flight (TOF)(APS) and another cascade impactor (GS1-CI) were compared with the A-MPCI. Two types of nebulizer (Pari LC+ and Microneb) were tested with all apparatuses, and a third type of nebulizer (NL9) was tested with the A-MPCI and Mastersizer-X. Nebulizers were charged with a solution of sodium fluoride in conditions reproducing the European Committee for Normalization (CEN) protocol. There was no difference between the Mastersizer-X and the A-MPCI or between the GS1-CI and the A-MPCI in terms of mass median aerodynamic diameter (MMAD). Comparison between the APS and the A-MPCI showed a significant difference with the Microneb. The geometric standard deviations (GSD) obtained with the A-MPCI were on average 10% greater than GSD obtained with the other apparatuses, but the differences were not statistically significant. We conclude that laser diffraction can be used for particle size distribution in the context of the European standard, and that the Mastersizer-X is particularly interesting for industrial practice in view of its simplicity and robustness.

[Optimization of aerosol therapy in otorhinolaryngology: stability and granulometry of dexamethasone-gomenol-framycetin solution]

Nebulization of solutions associating gomenol, dexamethasone and framycetin is very widespread in otorhinolaryngology (particularly for the treatment of actue laryngitis and post-traumatic laryngitis and rhinitis and for the tracheotomy care). A rigorous clinical evaluation is however lacking. The aim of this work was to evaluate use of such solutions in comparison with the recommendations issuing from the National Session in April 1997 on good practices for aerosol therapeutics. Stability and granulometry were studied in order to optimize processing. A new formulation and new technical methods of administration are proposed in relation to the results of this study and the national recommendations.

Inhaled fenoterol-ipratropium bromide in mechanically ventilated patients with chronic obstructive pulmonary disease

In 18 patients with chronic obstructive pulmonary disease intubated and mechanically ventilated, we prospectively randomized 200 micrograms fenoterol-80 micrograms ipratropium bromide (four puffs) from a metered-dose inhaler (MDI) versus 1.25 mg fenoterol-500 micrograms ipratropium bromide in 5 ml saline from a nebulizer (NEB). Respiratory mechanics were assessed before and 30 min after the end of each delivery by the rapid end-inspiratory airway occlusion technique. We did vary on single breaths the inflation flow (V) from 0.2 to 1.2 L. s-1, at constant inflation volume. The total respiratory resistance of the respiratory system (Rrs) was partitioned into airway (Rint,rs) and tissue (DeltaRrs) resistances. We found that Rrs was equivalently reduced, from 16.49 +/- 1.37 to 14.85 +/- 1.88 cm H2O. L-1. s with MDI (p < 0.05) and from 18.04 +/- 1.85 to 15.15 +/- 1.33 cm H2O. L-1. s with NEB (p < 0.01). Whereas the prevailing effect of MDI was to reduce Rint,rs, that of NEB was to decrease DeltaRrs. In addition, the V resistance of the respiratory system over the whole range of V was significantly affected by NEB but not by MDI.

Experimental measurements of particle retention efficiency of filters used to prevent contamination in respiratory devices

OBJECTIVE

Various types of filters have been designed to prevent cross contamination of ventilation and respiratory devices. The aim of this study was to experimentally measure the retention efficiency of four simple filters (antibacterial and antiviral and seven combined filters (antibacterial and antiviral plus heat and water exchangers).

SETTING

The respiratory function testing (EFR) central department of a university teaching hospital.

MEASUREMENTS AND RESULTS

The same aerosol test with a wide range of particle sizes (0.15 to 15 micrometers) was used to compare the retention efficiency of each filter used in various conditions. The particle sizes and the concentration of the aerosol were measured by a laser velocimeter. For all the filters studied, the retention efficiency was found to be higher than 99%. However some of them let large particles let through.

CONCLUSION

These data, performed in vitro, should be assessed also by further clinical studies.

Nebulized cyclosporine for prevention of acute pulmonary allograft rejection in the rat: pharmacokinetic and histologic study

BACKGROUND

With regard to limiting the systemic effects of cyclosporine A and obtaining better control of acute pulmonary allograft rejection, local immunosuppressive therapy with aerosolized cyclosporine A seems of interest. Given the in situ immunologic mechanisms of acute rejection, as well as the anatomic structure of the lung, this therapy is feasible as previously described by others. The aim of our study is to determine the pharmacokinetic parameters of nebulized cyclosporine A and the best modalities of administration.

METHODS

In a pharmacokinetic study, the cyclosporine A was given either by intramuscular injection (10 mg/kg) or by aerosol at 10 and 25 mg/kg doses; 70 rats were killed at 25 and 50 minutes and 2, 4, 6, 8, 12, 24, or 48 hours after cyclosporine A administration. Cyclosporine A levels were measured in whole blood and in the lung. The areas under the concentration time curves were determined. Twenty-four lung transplantations were then performed. The rats were killed on postoperative day 9. Acute rejection was scored on a scale of 0 to 4, and cyclosporine A trough levels were measured in the lung and in the blood.

RESULTS

With a jet nebulizer, the mass median aerodynamic diameter was 2.5 microns, with a standard geometric deviation of 2.3. In blood, the area under the concentration curve was greater for intramuscular (80.6 ng.hr/ml) than for aerosol administrations at 10 (15.1 ng.hr/ml) and 25 mg/kg (41.0 ng.hr/ml) doses. In the lungs, the area under the concentration curve was greater for the aerosol route at 25 mg/kg doses (588 ng.hr/mg) than for the low-dose (200 ng.hr/mg) or intramuscular administration (200 ng.hr/mg). The lung targeting index of cyclosporine A (ratio area under the concentration curve-lungs/area under the concentration curve-blood) was greater for both aerosol administrations than for the intramuscular route. In the study of the prevention of acute rejection, rats without immunosuppression (n = 6), rats receiving daily doses of cyclosporine A intramuscularly (10 mg/kg), and rats with aerosolized cyclosporine A daily (10 and 25 mg/kg/day) showed mean grades of acute rejection of, respectively, 4, 2.03 +/- 0.27, 2.33 +/- 0.52, and 2.17 +/- 0.46. The deposition of nebulized cyclosporine A was lower in transplanted than in native lung.

CONCLUSIONS

Nebulized cyclosporine A allows better pulmonary concentration than intramuscular administration, and results in lower systemic levels. Prevention of acute rejection is as good with aerosolized cyclosporine A as with intramuscular cyclosporine A. This first pharmacokinetic study of nebulized cyclosporine A could lead to clinical applications.

Comparison of jet and ultrasonic nebulizers for alveolar targeting of methylprednisolone

The secondary systemic effects of oral corticosteroid therapy in chronic lung disease indicate the possible benefits of local therapy. The aim of this study was to show if alveolar targeting of a corticosteroid, methylprednisolone (MP), is possible, and to determine which type of nebulizer allows the most selective deposition into the alveoli. A jet nebulizer (Respirgard II) with 2 ml volume fill (R2), and an ultrasonic nebulizer (Ultraneb 99) with 4 ml volume fill (U4), were compared using a 40-mg dose of MP labelled 99Tcm human serum albumin. Particle size and MP-to-albumin binding were measured in the aerosol cloud. Each nebulizer was used in random order in five healthy volunteers. A dynamic posterior scan of 68 images of 15 s each was performed with a Gammatome II gamma camera during inhalation. Peripheral and central regions of interest were automatically defined with reproducible methods, and the peripheral-to-central ratio was used as a penetration index. Stomach and oropharynx activities were estimated on static anterior and static left lateral views, respectively, at the end of the examination. The mass median aerodynamic diameter (MMAD) was lower for R2 when unlabelled MP was used. The MMAD of MP+HSA was compatible with alveolar targeting. In the aerosol cloud, MP-albumin binding was 75% for R2 and 79% for U4. Peripheral and central activities at equilibrium (13-16 min) were higher with U4, but the penetration index was significantly higher with R2. Moreover, the stomach and oropharynx activities were significantly lower with R2.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary deposition of aerosolised pentamidine using a new nebuliser: efficiency measurements in vitro and in vivo

The therapeutic efficacy of nebulised pentamidine in the prophylaxis of Pneumocystis carinii pneumonia (PCP) depends on the absolute pulmonary deposition of the drug. We studied the performance of a new nebuliser (Pentasave) by comparison both in vitro and in vivo with a standard nebuliser (Respirgard II). In vitro, deposition of pentamidine labelled with technetium-99m human serum albumin was measured indirectly by capturing inhaled particles on an absolute filter and measuring radioactivity with a gamma camera. The nebulisers were initially assessed with a pentamidine dose of 100 mg in 5 ml at 44 psi and an air flow of 10 l/min for Respirgard II and 16 l/min for Pentasave. Nebuliser output, expressed as the percentage of the initial nebuliser radioactivity captured by the inhalation filter, was 15% +/- 2% (mean +/- SD) for Respirgard II, and significantly increased to 23% +/- 3% for an initial version and to 33% +/- 2% for the final version of Pentasave. Measurements with a gamma camera in a group of ten patients with human immunodeficiency virus infection were made in vivo. The results revealed that pulmonary drug distributions are good using both Respirgard II and Pentasave. The literature reports that once-monthly pulmonary deposition of 9 mg pentamidine seems enough to produce prophylactic effects against Pneumocystis carinii. We measured pulmonary pentamidine deposition of 20.22 +/- 4.31 mg (mean +/- SD) using Respirgard II (with 300 mg in 5 ml) and of 16.00 +/- 7.18 mg using Pentasave (with 150 mg in 6 ml). These findings show that the therapeutic dose of pentamidine (9 mg) was widely exceeded with both nebulisers. Further investigations might demonstrate that about 200 mg and 125 mg pentamidine for Respirgard II and Pentasave, respectively, will achieve a pulmonary deposition of therapeutic dose, allowing significant savings in terms of drug and expense.

[Granulometry and measurement of a aerosol drug deposit (fusafungine) in normal and pathological airways]

We measured with a laser velocimeter granulometric deposit of an aerosol anti-infectious agent, fusafungin, administered with a controlled inhalator. Total drug deposit was determined on the basis of a granulometric spectrum of the polydispered aerosol (mass mean aerodynamic diameter (MMAD) = 2.8 +/- 1.7 microns) and dispersion in the airways was estimated using the Stahlhofen model. We first compared deposits obtained with oral inhalation in 19 normal subjects and 20 patients with chronic obstructive lung disease. Total deposit in the airways of patients with chronic obstructive lung disease (82%) was not significantly different from that in normal subjects (85%). Estimated dispersion in normal airways was 27% in the alveoles, 8.4% in the tracheobronchic region and 23.5% in the extrathoracic regions. We then compared deposits after nasal inhalation in 22 normal subjects and 21 patients with rhinitis: nasal deposit was significantly greater in patients with rhinitis (54.5%) than in controls (44.7%). We conclude that such an inhalator can be adapted for local treatment of ENT infections and upper respiratory infections. Deposit is not modified in case of obstructive bronchopathy.

Direct isotopic assessment of aerosolized pentamidine deposition: influence of nebuliser

OBJECTIVES

The aim of the present study was to compare the efficiency of pulmonary deposition of pentamidine using the Respirgard II jet nebuliser or the Fison ultrasonic nebuliser with 99m technetium (99m Tc) labelled pentamidine in the current conditions of recommended treatment. The study was designed in three stages, to verify particle size distribution, to validate the isotope labelling, and to compare pulmonary deposition of pentamidine isethionate with the two nebulisers.

METHODS

Count median aerodynamic diameter and mass median aerodynamic diameter were measured using the velocimetry technique and aerosol dispersion was calculated according to the standard deviation defined by the ratio of diameters between 84.3% and 50% of the total distribution. Stability of labelling was checked both in vitro, by radiochromatography, and in vivo, by the absence of free technetium thyroid fixation after intravenous injection of the preparation to a rat and inhalation by baboons. The direct isotopic technique was used to compare pulmonary deposition of 300 mg aerosolized 99m Tc labelled pentamidine isothionate with the two nebulisers in four HIV patients treated with primary prophylaxis.

RESULTS

Count median aerodynamic diameter and mass median aerodynamic diameter (MMAD) were higher with Fisoneb than with Respirgard II. Nevertheless Fisoneb MMAD remained in the optimal range for peripheral deposition. In one patient, pentamidine lung burden was higher using the Respirgard II (13% of dose originally in nebuliser) when compared with the Fisoneb (10.2% of dose originally in nebuliser). A better result was obtained in the 3 other patients with Fisoneb (mean = 14.3%) compared with Respirgard II (mean = 3.8%). In all 4 patients gastric contamination was higher with Fisoneb (mean = 5.2%) as compared with Respirgard II (mean = 2.6%). Cough and bronchospasm were not observed with either device.

CONCLUSION

This study showed that Fisoneb, a practical and cheap nebuliser which has proved to be effective in clinical studies when used for pentamidine nebulisation, leads to correct particle size distribution and pulmonary deposition of the drug. We believe that such studies to evaluate aerosol characteristics should be recommended for any kind of nebuliser.

Particle deposition and resistance in the noses of adults and children

Nasal filter efficiency for particles has been described by several authors as showing large individual variations, probably somehow related to airflow resistance. Twelve children, aged 5.5-11.5 yrs and 8 aged 12-15 yrs were compared to a group of ten adults. Deposition of polystyrene beads (1, 2.05, 2.8 microns mass median aerodynamic diameter (MMAD] was measured by comparing inhaled aerosols and exhaled air concentrations, for both nose and mouth breathing. Ventilation was controlled to scale breathing patterns appropriate for each age either at rest or during moderate exercise to allow comparison between subjects in similar physiological conditions. Anterior nasal resistance (as a function of flow rate) and standard lung function were measured for each subject. For the same inhalation flow rate of 0.300 l.s-1, children had much higher nasal resistances than the adults, 0.425 +/- 0.208 kPa.l.1.s under 12 yrs, 0.243 +/- 0.080 kPa.l.1.s over 12 yrs and 0.145 +/- 0.047 kPa.l.1.s in adults. Individually, nasal deposition increased with particle size, ventilation flow rate and nasal resistance, from rest to exercise. The average nasal deposition percentages were lower in children than in adults, in similar conditions: at rest, 12.9 and 11.7 versus 15.6 for 1 microns; 13.3 and 15.9 versus 21.6 for 2.05 microns; 11 and 17.7 versus 20 for 2.8 microns. This was even more significant during exercise, 17.8 and 15.9 versus 29.2 for 1 microns; 21.3 and 18.4 versus 34.7 for 2.05 microns; 16 and 16.1 versus 36.8 for 2.8 microns.(ABSTRACT TRUNCATED AT 250 WORDS)

Particle deposition and resistance in the noses of adults and children

Nasal filter efficiency for particles has been described by several authors as showing large individual variations, probably somehow related to airflow resistance. Twelve children, aged 5.5-11.5 yrs and 8 aged 12-15 yrs were compared to a group of ten adults. Deposition of polystyrene beads (1, 2.05, 2.8 microns mass median aerodynamic diameter (MMAD] was measured by comparing inhaled aerosols and exhaled air concentrations, for both nose and mouth breathing. Ventilation was controlled to scale breathing patterns appropriate for each age either at rest or during moderate exercise to allow comparison between subjects in similar physiological conditions. Anterior nasal resistance (as a function of flow rate) and standard lung function were measured for each subject. For the same inhalation flow rate of 0.300 l.s-1, children had much higher nasal resistances than the adults, 0.425 +/- 0.208 kPa.l.1.s under 12 yrs, 0.243 +/- 0.080 kPa.l.1.s over 12 yrs and 0.145 +/- 0.047 kPa.l.1.s in adults. Individually, nasal deposition increased with particle size, ventilation flow rate and nasal resistance, from rest to exercise. The average nasal deposition percentages were lower in children than in adults, in similar conditions: at rest, 12.9 and 11.7 versus 15.6 for 1 microns; 13.3 and 15.9 versus 21.6 for 2.05 microns; 11 and 17.7 versus 20 for 2.8 microns. This was even more significant during exercise, 17.8 and 15.9 versus 29.2 for 1 microns; 21.3 and 18.4 versus 34.7 for 2.05 microns; 16 and 16.1 versus 36.8 for 2.8 microns.(ABSTRACT TRUNCATED AT 250 WORDS)

Particle size study of nine metered dose inhalers, and their deposition probabilities in the airways

This study deals with the particle size measurement of nine aerosol metered dose inhalers. Calibration was made possible by the use of a laser particle velocimeter (aerodynamic Particle Sizer from TSI). The count median aerodynamic diameters (CMAD) show little variation, from 0.63 to 0.73 micron, with standard deviations (sigma g) between 1.2 and 1.8. Aerodynamic diameter aerosol diagram analysis showed multimodal mass distribution for all the tested dose inhalers. Calculations for the airway deposition probabilities (extrathoracic, tracheobronchial and alveolar) refer to the studies made by W. Stahlhofen and co-workers. As most aerosol metered dose inhalers have a predominantly bronchial therapeutic destination, the deposition at the bronchial level could be enhanced with the following parameters: inspired volume of 1500 ml, inspiratory time of 2 sec, aerosol mass median aerodynamic diameter (MMAD) of 7.5 microns, with a monodispersed distribution. The respective influences of the excipients and propellents used for the aerosolization of these dose metered inhalers are also discussed.

Particle size study of nine metered dose inhalers, and their deposition probabilities in the airways

This study deals with the particle size measurement of nine aerosol metered dose inhalers. Calibration was made possible by the use of a laser particle velocimeter (aerodynamic Particle Sizer from TSI). The count median aerodynamic diameters (CMAD) show little variation, from 0.63 to 0.73 micron, with standard deviations (sigma g) between 1.2 and 1.8. Aerodynamic diameter aerosol diagram analysis showed multimodal mass distribution for all the tested dose inhalers. Calculations for the airway deposition probabilities (extrathoracic, tracheobronchial and alveolar) refer to the studies made by W. Stahlhofen and co-workers. As most aerosol metered dose inhalers have a predominantly bronchial therapeutic destination, the deposition at the bronchial level could be enhanced with the following parameters: inspired volume of 1500 ml, inspiratory time of 2 sec, aerosol mass median aerodynamic diameter (MMAD) of 7.5 microns, with a monodispersed distribution. The respective influences of the excipients and propellents used for the aerosolization of these dose metered inhalers are also discussed.

Inhaled particle deposition and clearance from the normal respiratory tract

Tracheo-bronchial and pulmonary deposited fractions of inhaled insoluble particles and their clearances rates were studied in 16 healthy non-smokers. After oral inhalation of radioactive particles (Mean Mass Aerodynamic Diameter (MMAD) = 3 microns, sigma g = 1.4 labelled with 111In) incorporated radioactivity was measured for each subject both by a gamma camera from to until the 3rd day, then from the 3rd until the 5th day first by a gamma camera and then by a low background profile scanner and from the 5th until the 35th day by a low background profile scanner alone. Clearance rates were calculated from the biological half lives of the deposited tracers. All subjects performed respiratory function tests. Experimental data were fitted to a two-compartment exponential system with two biological half lives: T1 = 76 min for 30%, T2 = 3.15 days for 40% of the deposited material. The delayed clearance phase for the remaining 30% of the deposited material approaches a constant rate. Our clearance values were compared with those of the Task Group of Lung Dynamics (T.G.L.D.) and other authors' results, especially for T1 and T2. These values are analyzed in terms of mucus velocity and mucociliary transport in distal conductive airways. Impaired transport reduces natural defenses and increases toxicological hazards. Therefore reliable techniques for detecting such impairment may be important in evaluating pulmonary involvement in environmental respiratory disease.

[Short-term tracheobronchial clearance in apparently pure Gougerot-Sjögren syndrome]

Bronchopulmonary involvement in the Sjögren syndrome can lead to distal obstructive airway disease. This syndrome induces a decrease in secretions which become rare and thick, and consequently a slowing down of mucociliary activity. This activity, which can be estimated by tracheobronchial clearance studies, was investigated in seven non-smoking women (mean age = 56.7 yr) with the Sjögren syndrome but without patent distal bronchial impairment. After oral inhalation of radioactive particles labelled with 111In during spontaneous breathing (MMAD = 3 micrograms; sigma g = 1.4; energies gamma 173 and 247 keV, radioactive half-life = 2.8 days), the incorporated radioactivity was measured by a gamma-camera at the end of inhalation and then every 5 min throughout 90 min and 2, 4, 5, 6 and 24h thereafter. Biological decrease in radioactivity was exponential in form. Considering, as may authors do, the clearance of the tracheobronchial compartment to be completed within 24h, we calculated an initial biological period corresponding to the beginning of this clearance. It was equal to 101 +/- 27 min in 12 normal subjects. It was normal in three of our patients (T = 90, 91 and 101 min) and longer for the four others (T = 178, 203, 240 and 304 min). We hypothesize that three of these four patients with slow clearance and normal penetration index (tracheobronchial deposition/pulmonary deposition) had bronchiolar involvement, creating anomalies in the mucociliary escalator which were undetectable by clinical, radiological or functional examinations. These results argue in favour of strict pulmonary surveillance in patients with altered short-term clearances to enable early detection of bronchiolar disease.

Pulmonary function after transverse or midline incision in patients with obstructive pulmonary disease

Atelectasis and bronchopneumonia occur frequently in patients undergoing aorto-iliac reconstructive surgery. Transverse (T) incisions in upper abdominal surgery are thought to be followed by fewer pulmonary complications than midline incisions (M) but reports remain controversial. We studied the incidence of postoperative pulmonary complications and lung dysfunction after T and M incisions for aorto-iliac surgery in 13 patients with chronic obstructive pulmonary disease (COPD) and 13 control patients with normal lungs (C). For all subjects, we evaluated (1) postoperative clinical or radiological pulmonary events; (2) preoperatively and on postoperative days 2 (D2), 5 (D5), 9 (D9) and 12 (D12) - the forced expiratory volume in 1 s (FEV1), vital capacity (VC), alveolar-arterial oxygen difference (AaPO2), and (3) convenience for the surgeon. Operatively, aortic exposure was excellent with both incisions. Bronchopneumonia occurred only after M in five patients (1 C, 4 COPD). In contrast with the control patients in whom no difference was found between T and M incisions, the FEV1 of COPD patients was significantly less impaired with T than with M incisions (p less than 0.005 on D2 and p less than 0.05 on D5). VC decreased similarly with both incisions on D2 but on D5 the improvement was less with M (p less than 0.005). Changes in AaPO2 were more marked on D2 and D5 for the COPD patients with M incisions. We conclude that (1) in patients with chronic obstructive pulmonary disease, laparotomy with a transverse incision was associated with better postoperative lung function and fewer pulmonary complications; (2) in patients without pulmonary disease, midline and transverse incisions were equivalent.