Extracorporeal Lung Assist with Heparin-Coated Systems

Extracorporeal lung assist (ELA) has been recommended for the treatment of ARDS if conventional therapy fails. However, the need for nearly complete anticoagulation is a major risk factor for hemorrhagic complications. We describe our experience with 13 ARDS patients treated with ELA using heparin-coated systems (Carmeda). Maintaining partial thromboplastin time and activated clotting time within or close to the normal range, even major surgery (20 thoracotomies and 2 laparotomies) could be performed without undue bleeding complications related to anticoagulation during extracorporeal support. Eight of the 13 patients survived. The use of heparin-coated systems allows prolonged ELA with nearly physiological coagulation function, permitting major surgical intervention. It enhances the safety margin of extracorporeal gas exchange and may ultimately extend its indications.

Factors associated with treatment default by tuberculosis patients in Fez, Morocco

Interruption in tuberculosis (TB) treatment still remains the most important challenge for control of the disease. This study aimed to identify the determinants of TB treatment default in Fez, Morocco. A 1:2 pair-matched case-control study was carried out in the TB control units in Fez. Cases were defaulters to TB treatment and were matched by age and sex to non-defaulters (controls). Of the 320 patients (108 defaulters, 212 controls), 80.6% were male. The main reason for defaulting reported by patients was the sensation of being cured. Predictive factors for treatment default in the multivariate conditional logistic regression analysis, were: relapsed case (adjusted OR = 4.49; 95% Cl: 1.87-10.8), current smoking (aOR= 2.10; 95% Cl: 1.07-4.14), alcohol use (aOR = 2.92; 95% Cl: 1.04-8.19), being more than 30 minutes away from the health centre (aOR = 3.34; 95% Cl: 1.06-10.5) and perception of having received insufficient explanation about the disease (aOR = 2.87; 95% CI: 1.53-5.36). The rate of defaulting in Fez can be lowered through targeted and realistic measures.

Knowledge and attitude about antismoking legislation in Morocco according to smoking status

Despite tobacco control legislation enacted in Morocco in 1996, the Moroccan population appears to have little interest in or awareness of tobacco control measures. This household survey aimed to assess sectional study was conducted on a random sample of 9195 Moroccans. Only 33.3% knew about the antismoking legislation: 38.7% of smokers versus 32.3% of non-smokers. Among the 3050 people who knew about the law, 60.1% knew about the ban on smoking in public areas and 22.4% knew there was an obligatory health warning on tobacco packaging. The attitude questions showed that 27.2% agreed that the price of tobacco products should increase sharply and 45.0% that antismoking legislation should prohibit tobacco sales to children. These data demonstrate low levels of information among Moroccans concerning current tobacco control legislation.

Burden of smoking in Moroccan rural areas

The aim of this study was to estimate the prevalence and characteristics of current smoking among rural Moroccans. The population study included 3438 individuals aged 15 years and above from both sexes. The crude prevalence of current smoking (currently smoked and had smoked > 100 cigarettes in lifetime) was 16.9% in the adolescent and adult rural population: 31.0% among men and 1.1% among women. The majority of smokers 74.4% of men and 68.8% of women) began smoking before age 20 years. Multiple logistic regression analysis showed that age, sex, marital status, occupation and region of residence were the strongest determinants of current smoking. These results showed a high prevalence of smoking among males in the rural population of Morocco.

Indoor solid fuel combustion and tuberculosis: is there an association?

OBJECTIVES

To assess the strength of evidence in published articles for an association between indoor solid fuel combustion and tuberculosis.

METHODS

PubMed, a private database and Google Scholar were searched up to May 2008, as was the Cochrane Library (2008, issue 4), to identify articles on the association between indoor air pollution and tuberculous infection, tuberculosis disease and tuberculosis mortality. Each article initially chosen as acceptable for inclusion was reviewed for data extraction by three different reviewers using a standard format. Strength of evidence was determined by pre-determined criteria.

RESULTS

The full texts of 994 articles were examined for a final selection of 10 possible articles, of which six met the inclusion criteria. All articles investigated the association between exposure to solid fuel (coal and biomass) smoke and tuberculosis disease. Three (50%) of the six studies included in the systematic review showed a significant effect of exposure to solid fuel combustion and tuberculosis disease-one high-quality case-control study and two cross-sectional studies.

CONCLUSION

Despite the plausibility of an association, available original studies looking at this issue do not provide sufficient evidence of an excess risk of tuberculosis due to exposure to indoor coal or biomass combustion. Because the number of studies identified was small, new studies are needed before more definitive conclusions can be reached.

Inequalities in smoking profiles in Morocco: the role of educational level

BACKGROUND

Cigarette smoking is increasingly associated with lower socio-economic status, indicated by lower educational levels. This association has never been investigated in Morocco.

OBJECTIVE

The MARTA survey was undertaken to assess tobacco use in the Moroccan population according to level of education and other socio-demographic characteristics.

METHODS

A cross-sectional survey based on a representative sample of the Moroccan population was conducted in 2005-2006. The survey questionnaire gathered socio-demographic information, educational level and smoking status. chi(2) analyses were performed to determine whether the smoking outcome variables differed significantly between different educational levels in relation to demographic variables. Multiple logistic regression analysis was used to calculate the adjusted odds ratio for smoking status according to educational level.

RESULTS

A total of 9195 subjects were included in the study; 52% were men and 17.9% illiterate. The overall prevalence of current smoking was 18.0% (95%CI 17.2-18.8): 31.5% (95%CI 30.2-32.9) in males and 3.3% (95%CI 2.8-3.8) in females. The prevalence of current smoking was inversely associated with level of education in men and increased with educational level in women. Illiterate males tended to have a higher probability of being current smokers than males with university-level education (OR 1.93, 95%CI 1.51-2.46).

CONCLUSION

These results indicate a need for tobacco control to reach all sectors of society, and especially the illiterate population.

Global perspective on tobacco control. Part I. The global state of the tobacco epidemic

Tobacco smoking is losing adherents in some countries, and a number of international developments may dramatically change the choices people make concerning tobacco. However, the growth of chronic obstructive pulmonary disease (COPD) in the world is nevertheless assured-tobacco consumption is rising globally because of increased consumption in many low-income countries. Risk of COPD is strong wherever smokers are found, and even among former smokers, it remains high for decades. Both COPD and smoking produce lower measurable quality of life assessment, but little attention is given to the association, apart from noting that cessation rates are poor among COPD patients. Tobacco smoking rates vary; men usually smoke more than women in overall consumption and in prevalence. Current available estimates are 49% for men and 8% for women in low- and middle-income countries, and 37% for men and 21% for women in high-income countries. These figures give little information, however, because there can be variations within and across populations. What is important is that about a third of all adults in the world currently smoke, and that it will take a tremendous turnaround to put a halt to the overall growth of tobacco use. Smoking-related COPD rates will continue to be high for some time. The future of COPD is related most dramatically to low- or middle-income countries, where more than four in five current smokers in the world live. The predictable health consequences of smoking, including an enormous burden in COPD, have only begun to emerge.

Tobacco and tuberculosis: a qualitative systematic review and meta-analysis

OBJECTIVES

To assess the strength of evidence in published articles for an association between smoking and passive exposure to tobacco smoke and various manifestations and outcomes of tuberculosis (TB). Clinicians and public health workers working to fight TB may not see a role for themselves in tobacco control because the association between tobacco and TB has not been widely accepted. A qualitative review and meta-analysis was therefore undertaken.

METHODS

Reference lists, PubMed, the database of the International Union Against Tuberculosis and Lung Disease and Google Scholar were searched for a final inclusion of 42 articles in English containing 53 outcomes for data extraction. A quality score was attributed to each study to classify the strength of evidence according to each TB outcome. A meta-analysis was then performed on results from included studies.

RESULTS

Despite the limitations in the data available, the evidence was rated as strong for an association between smoking and TB disease, moderate for the association between second-hand smoke exposure and TB disease and between smoking and retreatment TB disease, and limited for the association between smoking and tuberculous infection and between smoking and TB mortality. There was insufficient evidence to support an association of smoking and delay, default, slower smear conversion, greater severity of disease or drug-resistant TB or of second-hand tobacco smoke exposure and infection.

CONCLUSIONS

The association between smoking and TB disease appears to be causal. Smoking can have an important impact on many aspects of TB. Clinicians can confidently advise patients that quitting smoking and avoiding exposure to others' tobacco smoke are important measures in TB control.

Providing and monitoring quality service for smoking cessation in tuberculosis care

All tobacco smokers should be identified and provided with a smoking cessation intervention (SCI) during tuberculosis (TB) treatment. To ensure that this occurs, the intervention process should be recorded and monitored. Monitoring is the best guarantee that care is standardised and offered equitably to all patients. It allows for evaluation of processes and outcomes so that population needs can be identified and appropriate techniques added or updated. In this article we propose steps for brief intervention as a part of the monitoring process, using model forms and suggested procedures for filling them in. The suggested forms are a modified TB treatment card that includes information about tobacco use, an SCI patient card to be added to the patient's TB treatment folder, SCI registers and SCI quarterly report forms and a tobacco use questionnaire for evaluation of services.

Helping patients to stop smoking

Cognitive-behavioural strategies can be used for smokers who request assistance in stopping smoking. These strategies are based on social learning theory, which defines smoking cessation as a process of breaking all of the emotional and situational ties that have been established with the act of smoking. To do this, the quitting smoker needs to understand the addiction process as well as conditioned responses to it in dealing with withdrawal symptoms and craving. The health worker can help the quitting smoker by providing techniques to understand what and how smoking reinforces itself, to enhance and maintain motivation to remain abstinent, to encourage using a social support system and to plan the coping techniques that might be used. Both acts (behaviours) and thinking (cognitions) can be powerful tools in persevering to cope with craving and to manage undesirable side-effects of cessation. These include identifying the antecedents (cues to use tobacco) and the consequences of using tobacco to identify critical emotions and situations where coping is most necessary, finding activities to replace the act of lighting a cigarette, mentally preparing for craving and keeping at bay unhelpful thoughts (such as 'I'll just take one last puff'). Mental preparation is also necessary to understand and to avoid or limit the side effects of cessation.

Tobacco cessation and brief advice

Patients who are enrolled on tuberculosis (TB) treatment are often ill and are seeking ways to get better. They are more likely at that time to adopt risk-reducing health behaviours. Interventions that are neither complicated nor time-consuming are available to health service personnel to help patients undertake smoking cessation. Brief advice to patients repeated at various times throughout their TB care can increase cessation rates. All tobacco use needs to be identified and reasons for quitting enunciated. Patients are thus given a framework for considering smoking cessation. If patients then choose not to stop currently, they can be asked to reconsider at a later visit, and also be cautioned to avoid smoking in the presence of others. Smokers who want to stop can discuss strategies for avoiding craving and withdrawal, and pharmacological agents can be recommended if they are available. Because the brief advice is repeated, patients are reinforced either for having stopped or for their progress towards stopping.

Introducing brief advice in tuberculosis services

There are individual and contextual barriers to the adoption of new routines in health care. Health professionals working in tuberculosis (TB) care are unlikely to adopt smoking cessation interventions unless they understand the importance of such interventions, feel that doing them will produce results and are convinced that the interventions should be used. Health professionals need to know what they are expected to do and to feel they have the skills or tools necessary. But beyond informed, willing and ready health care providers, the health care service also needs to provide an encouraging infrastructure. Tobacco cessation has to be included in standard practice guidelines on TB case management, and information about smoking should be included in the standard monitoring process, with appropriate forms. Programme managers and technical advisors need to ask about, encourage and support the inclusion of smoking cessation interventions. It is advisable for one staff member to coordinate tobacco cessation activities to ensure that needed materials are available and to provide assistance and feedback to other staff.

Tobacco use and tobacco control

Smoking begins when tobacco is readily available and others smoke. It easily becomes something more than experimentation, as the symptoms of nicotine dependence can develop rapidly. The social and environmental cues to smoke, the personal perceptions of smoking and the physiological effects of nicotine create strong links that are difficult to break. Programmes should be put in place to help people to stop smoking, but these programmes cannot reach their potential for success if the wider social and environmental factors are not also changed through strengthened anti-tobacco social values and tobacco control legislation, as exemplified in the WHO Framework Convention on Tobacco Control.

Cost-effectiveness of pharmacotherapies for nicotine dependence in primary care settings: a multinational comparison

OBJECTIVE

To estimate the incremental cost-effectiveness of the first-line pharmacotherapies (nicotine gum, patch, spray, inhaler, and bupropion) for smoking cessation across six Western countries-Canada, France, Spain, Switzerland, the United States, and the United Kingdom.

DESIGN AND STUDY POPULATION

A Markov-chain cohort model to simulate two cohorts of smokers: (1) a reference cohort given brief cessation counselling by a general practitioner (GP); (2) a treatment cohort given counselling plus pharmacotherapy. Effectiveness expressed as odds ratios for quitting associated with pharmacotherapies. Costs based on the additional physician time required and retail prices of the medications.

INTERVENTIONS

Addition of each first-line pharmacotherapy to GP cessation counselling.

MAIN OUTCOME MEASURES

Cost per life-year saved associated with pharmacotherapies.

RESULTS

The cost per life-year saved for counselling only ranged from US190 dollars in Spain to 773 dollars in the UK for men, and from 288 dollars in Spain to 1168 dollars in the UK for women. The incremental cost per life-year saved for gum ranged from 2230 dollars for men in Spain to 7643 dollars for women in the US; for patch from 1758 dollars for men in Spain to 5131 dollars for women in the UK; for spray from 1935 dollars for men in Spain to 7969 dollars for women in the US; for inhaler from 3480 dollars for men in Switzerland to 8700 dollars for women in France; and for bupropion from 792 dollars for men in Canada to 2922 dollars for women in the US. In sensitivity analysis, changes in discount rate, treatment effectiveness, and natural quit rate had the strongest influences on cost-effectiveness.

CONCLUSIONS

The cost-effectiveness of the pharmacotherapies varied significantly across the six study countries, however, in each case, the results would be considered favourable as compared to other common preventive pharmacotherapies.

Associations between tobacco and tuberculosis

The association between smoking and tuberculosis (TB) has been investigated since 1918. Both passive and active exposure to tobacco smoke have been shown to be associated with tuberculous infection and with the transition from being infected to developing TB disease. The association between smoking and developing TB disease (without separating the risk of transition from being exposed to being infected and that from being infected to developing TB disease) has been reported substantially. Smoking affects the clinical manifestations of TB. It has been shown that ever smokers are more likely to have cough, dyspnoea, chest radiograph appearances of upper zone involvement, cavity and miliary appearance, and positive sputum culture, but are less likely to have isolated extra-pulmonary involvement than non-smokers. Smoking has been found to be associated with both relapse of TB and TB mortality. There appears to be enough evidence to conclude that smoking is causally associated with TB disease. Patients with TB need and should receive counselling and assistance in stopping smoking.

Feasibility of brief tobacco cessation advice for tuberculosis patients: a study from Sudan

SETTING

Twenty-four health care centres in Sudan.

OBJECTIVE

To examine the feasibility of introducing a tobacco cessation intervention into tuberculosis (TB) treatment programmes.

DESIGN

A feasibility study of a tobacco cessation intervention for new cases of pulmonary tuberculosis (PTB) in men compared survey centres (controls) and tobacco cessation intervention centres. Feasibility was evaluated by examining 1) acceptance by health staff and 2) the impact of additional tasks on TB treatment outcomes. A secondary assessment looked at rate of stopping tobacco use among those enrolled in the intervention condition.

RESULTS

Staff members did not differ in personal use of tobacco, in enforcing rules banning the use of tobacco at health centres or in rates of recruitment into the study. A total of 513 patients (44% of those eligible) were enrolled. Differences in TB treatment success were found between patients who were enrolled and those who were not: respectively 83% and 59% were cured or completed treatment. Of identified tobacco users undergoing the cessation intervention, 66% reported abstinence at the end of their TB treatment.

CONCLUSION

Although differences existed between patients enrolled or not enrolled, the intervention was demonstrated to be feasible to implement and effective for those enrolled within routine TB services.

[What are the epidemiological data concerning parental smoking and breastfeeding?]

Exclusive breastfeeding for 6 months provides important protection against respiratory infections in the newborn's first year of life. But smoking by either parent not only creates excess risk of respiratory illness for the baby, it also plays an important role both in not breastfeeding or in early weaning, thus depriving the infant of the potential protections of receiving mother's milk. Considering this information, three main recommendations can be made: promoting smoking cessation by the mother and also by the father may be a key to successful efforts to encourage breastfeeding; a smoking mother can enhance her chances of successful breastfeeding by avoiding smoking at least 2(1/2) hours prior to each feeding; a smoking father can enhance breastfeeding by avoiding exposing the mother as much as he should avoid exposing the infant to tobacco smoke.

Current challenges in tobacco control

Tobacco is the world's biggest preventable killer, but the circumstances of its history, the power and influence of its commerce and the nature of addiction make it a very difficult public health issue. Determinants of smoking are both individual and environmental. Genetics and environment influence to varying degrees all of the steps in a smoker's career. Persistence of use, degree of addiction to nicotine and difficulty in stopping are influenced by inherited traits and nicotine susceptibility, whereas the social environment and the individual's cognitions are the key factors in starting smoking and successfully stopping smoking. The tools available to tobacco control include influencing the social and cultural norms concerning tobacco; legislative and regulatory measures to protect the population and to limit tobacco industry marketing tactics, now encapsulated in the Framework Convention on Tobacco Control; and programmes to enhance the chance of not starting and successfully stopping. Strategies for tobacco control must work at both societal and individual levels, and directions are being taken that include genetic, pharmacological, behavioural, socio-cultural and international approaches.

The role of information, education and treatment in tobacco control

Because tobacco use is both an individual and a social behaviour, the efficacy of information, education and treatment addressed to smokers is greatly influenced by the inhibiting or facilitating effects of the environment and the social values given to smoking and to not smoking. The environment is a function of the evolution of tobacco use and the extent of tobacco control efforts. Information is the fuel for legislative and regulatory measures. These and public health education campaigns set the stage for building motivation and confidence to stop smoking and reinforce the social value of non-smoking. As individuals desire, and become prepared for, change, treatments help them address their needs. The role of information, education and treatment are interconnected. Each plays a different and necessary part in building and reinforcing social change and individual behaviour change. They are all needed to move populations and the individuals in those populations as rapidly as possible away from smoking.

Unilateral lung edema: effects on pulmonary gas exchange, hemodynamics, and pulmonary perfusion distribution

Two types of unilateral lung edema in sheep were characterized regarding their effects on pulmonary gas exchange, hemodynamics, and distribution of pulmonary perfusion. One edema type was induced with aerosolized HCl (0.15 M, pH 1.0) and the other with NaCl (0.15 M, pH 7.4). Both aerosols were nebulized continuously for 4 h into left lungs. In HCl-treated animals, pulmonary gas exchange deteriorated [from a partial arterial O(2) pressure-to-inspired O(2) fraction ratio (Pa(O(2))/FI(O(2))) of 254 at baseline to 187 after 4 h HCl]. In addition, pulmonary artery pressure and total pulmonary vascular resistance increased (from 16 to 19 mmHg and from 133 to 154 dyn. s. cm(-5), respectively). In NaCl-treated animals, only the central venous pressure significantly increased (from 7 to 9 mmHg). Distribution of pulmonary perfusion (measured with fluorescent microspheres) changed differently in both groups. After HCl application, 6% more blood flow was directed to the treated lung, whereas, after NaCl, 5% more blood flow was directed to the untreated lung. HCl and NaCl treatment both induce an equivalent lung edema, but only HCl treatment is associated with gas exchange alteration and tissue damage. Redistribution of pulmonary perfusion maintains gas exchange during NaCl treatment and decreases it during HCl inhalation.

Smoking cessation at the workplace. Results of a randomised controlled intervention study. Worksite physicians from the AIREL group

OBJECTIVES

To compare the effects of a worksite intervention by the occupational physician offering simple advice of smoking cessation with a more active strategy of advice including a "quit date" and extra support.

POPULATION

Employees of an electrical and gas company seen at the annual visit by their occupational physicians. CRITERIA END POINTS: Smoking point prevalence defined as the percentage of smokers who were non-smokers at one year. Secondary criteria were the percentage of smokers who stopped smoking for more than six months and the difference in prevalence of smoking in both groups.

METHODS

Randomised controlled trial. The unit of randomisation was the work site physician and a random sample of the employees of whom he or she was in charge. The length of the follow up was one year. Each of 30 work site physicians included in the study 100 to 150 employees.

RESULTS

Among 504 subjects classified as smokers at baseline receiving simple advice (group A) and 591 the more active programme (group B), 68 (13.5%) in group A and 109 (18. 4%) were non-smokers one year later (p=0.03; p=0.01 taking the occupational physician as the statistical unit and using a non-parametric test). Twenty three subjects (4.6%) in group A and 36 (6.1%) in group B (p=0.26) declared abstinence of six months or more. Among non-smokers at baseline, 3.4% in both groups were smokers after one year follow up. The prevalence of smokers did not differ significantly at baseline (32.9% and 32.4%, p=0.75). After the intervention the prevalence of smoking was 30.8% in group A and 28. 7% in group B (p=0.19). An increase of the mean symptoms score for depression in those who quit was observed during this period.

CONCLUSIONS

A simple cessation intervention strategy during a mandatory annual examination, targeting a population of smokers independently of their motivation to stop smoking or their health status, showed a 36% relative increase of the proportion of smokers who quit smoking as compared with what can be achieved through simple advice.

French general practitioners' attitudes and reported practices in relation to their participation and effectiveness in a minimal smoking cessation programme for patients

AIMS

To examine the participation and effectiveness of GPs in offering a minimal smoking cessation intervention according to attitudinal and reported behaviour variables.

DESIGN

General practitioners were surveyed about their practices and attitudes and then matched pairs of smoking and non-smoking doctors were invited to participate in a regional smoking cessation intervention. The relationship of survey responses and the degree of participation and effectiveness in a smoking cessation trial was examined.

SETTING

Primary care doctors in a large region of southern France, Provence-Alpes-Côte d'Azur (PACA).

PARTICIPANTS

Two thousand, eight hundred and sixty GPs from the PACA region in France were interviewed about their attitudes and behaviours. From among 371 smoking GPs and 375 non-smoking GPs invited to take part in a smoking cessation trial with patients, 170 smokers and 202 non-smokers participated.

MEASUREMENTS

The GPs' attitudes and reported professional and personal practices were assessed in a telephone interview. These responses were compared with the GPs' participation in the cessation trial, and with GP "success" (1 or more patients stopping smoking at 1 month, 12 months or both) or "non-success" (no patient cessation at 1 month or at 12 months).

FINDINGS

A significantly lower proportion of smokers than non-smokers among the GPs who initially accepted did not participate in the study (45% vs. 54.1%, chi 2 = 5.147 df = 1, p < 0.05, difference: 8.3% 95% CI: 1.2%; 15.5%), but thereafter, there were no significant associations between GPs' reported smoking practices and attitudes and the extent of their participation or effectiveness.

CONCLUSIONS

The study results indicate that, when minimal advice has an effect, it is due more to the systematic nature of the provision of the intervention than to the attitudes or reported practices of the practitioner providing the advice.

Temperature Regulation of Supercooling and Gut Nucleation in Relation to Diapause of Pyrrhocoris apterus (L.) (Heteroptera)

The heteropteran Pyrrhocoris apterus (L.) does not survive freezing of its body fluids; there is a good correlation between values of survival at subzero temperatures and the supercooling point (SCP), i.e., the temperature at which body fluids start to freeze. The decrease of the SCP and thus the increase in cold hardiness is regulated by photoperiod and temperature. The relative importance of these factors depends on the physiological state of the insect. The SCP is about -7&deg;C at the onset of prediapause and a decrease of about 4-5&deg;C is associated with the development of the diapause syndrome in adults; these processes both are induced by a short-day photoperiod with temperature playing a secondary role. The induction of the diapause syndrome is a prerequisite for the subsequent decrease of the SCP by about 5-6&deg;C during cold acclimation. An intermediate temperature of 15&deg;C, or fluctuating outdoor temperatures and short-day photoperiods, are more suitable for the decrease of SCP than 5&deg;C in continuous darkness. The sensitivity to photoperiod gradually disappears during the development of diapause; after the termination of diapause around the winter solstice the SCP irreversibly increases at a high temperature of 26&deg;C even if exposed to a short-day photoperiod. The SCPs of hemolymph, gut, fat body, and gonads were compared to whole-body SCP. The gut was identified as the primary site of ice nucleation because its SCP value was very similar to the value for the whole body in both short-day and long-day insects. The SCPs of other organs, including the hemolymph, were always lower than the whole body SCP. Food was not a source of ice nucleating agents because the SCP of freshly ecdysed adults remained high after 2 weeks of starvation. In contrast, feeding was a prerequisite for the decrease of the SCP during prediapause. In postdiapause insects, the SCP increased at high temperatures in spite of the absence of food.

Validation and clinical application of a continuous P0.1 measurement using standard respiratory equipment

The airway occlusion pressure, P0.1, is the negative airway pressure generated during the first 100 msec of an occluded inspiration. P0.1 is a parameter for the neuro-muscular activation of the respiratory system, which is an important determinant for the work of breathing. It has been shown to be a good predictor for successful weaning from mechanical ventilation. Standard P0.1 measurement techniques are based on a total occlusion of the inspiration for more than 100 msec. These measurements are technically complex and therefore not useful for clinical purposes. Furthermore, a significant breath-by-breath variability has been shown for P0.1, which is neglected by any single point measurement technique. Therefore, we have developed a continuous on-line measurement for breath-by-breath determination of P0.1 using the Siemens Servo 900C respirator. In triggered mechanical ventilation the delay time between the onset of the patient's inspiration and flow delivery from the respiratory is more than 100 msec for this respirator. During that time the inspiration is occluded. Therefore, the trigger effort was proposed to be a good estimate of P0.1. Based on this, we calculated P0.1 as follows: airway pressure (Paw) was registered at the endotracheal tube site of the respiratory tubing, digitized and acquired by a personal computer at 100 Hz. The recorder output of the Servo 900C was connected to the same computer, delivering the electronical signal for the inspiratory valve to open when the inspiratory effort has exceeded the trigger threshold, which needs a minimal delay time of 80 msec. Around 20 msec after this signal flow is delivered from the respirator. The computer runs an algorithm, which recognizes this signal and calculates P0.1 (Servo P0.1) as the slope of the pressure drop during this 100 msec. Paw tracings and the calculated P0.1 values were displayed on the computer screen and stored on disk. This method was validated by comparing it to the standard technique, using a Hans-Rudolph valve for inspiratory occlusion and calculating P0.1 from Paw tracings during the occluded inspiration. For validation we used a mechanical lung model which generated P0.1 values ranging between 1.1-10.3 mbar. For a given adjustment of the lung model two standard measurements (standard P0.1) were made and compared to the Servo P0.1. In a total of 21 measurements the mean Servo P0.1 was 4.9 +/- 2.9 mbar; the mean standard P0.1 was 4.3 +/- 2.5 mbar. The mean difference between Servo P0.1 and standard P0.1 was 0.6 +/- 0.6 mbar (range: -0.3-1.8 mbar). The regression equation for linear regression analysis was: Servo P0.1 = 1.15* standard P0.1-0.05. This correlation was significant (r = 0.99, p < 0.01). From these data we conclude that the described method for continuous P0.1 measurement provides reliable values with the advantage of a maneuver-free, breath-by-breath measurement technique. It thereby opens the possibility for monitoring the neuro-muscular activation of the respiratory system at the bedside, which is shown as an example for a patient during weaning from mechanical ventilation.

A new method for P0.1 measurement using standard respiratory equipment

The airway occlusion pressure, P0.1, is an index for the neuro-muscular activation of the respiratory system. It has been shown to be a very useful indicator for the ability of patients receiving ventilatory support to be weaned from mechanical ventilation. Since the standard measurement technique for P0.1 determination is technically complex, it is not widely available for clinical purposes. For that reason a P0.1 measurement technique was developed as an integrated function in a standard respirator (Evita, Dräger, Lübeck, Germany). This technique is easy to use and does not need any further equipment. We validated this new technique by comparing it to standard P0.1 measurements in a mechanical lung model as well as in ventilated patients. In the lung model we found a correlation between the Evita measurement and standard measurements of r = 0.99. In 6 ventilated patients the correlation was r = 0.78. Since the Evita P0.1 and the standard measurement had to be performed during two different breaths, this little poorer correlation in patients may be due to a significant breath-by-breath variability in P0.1. Comparing the Evita P0.1 and the standard measurement within one breath resulted in a clearly better correlation (r = 0.89). We conclude that this new measurement technique provides an easy and accurate P0.1 measurement using standard respiratory equipment when tested in a lung model. In patient measurements the method is less precise, which is probably due to the variable waveforms of the inspiratory driving pressure seen in patients, for example when intrinsic PEEP is present.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of inhaled nitric oxide on right ventricular function in severe acute respiratory distress syndrome

OBJECTIVE

To compare the effects of inhaled nitric oxide (NO) and an infusion of prostacyclin (PGI2) on right ventricular function in patients with severe acute respiratory distress syndrome (ARDS).

DESIGN

Randomized prospective short-term study.

SETTING

Post-surgical ICU in an university hospital.

PATIENTS

10 patients with severe ARDS referred to our hospital for intensive care.

INTERVENTIONS

In random sequence the patients inhaled NO at a concentration of 18 parts per million (ppm) followed by 36 ppm, and received an intravenous infusion of PGI2 (4 ng.kg-1.min-1).

MEASUREMENTS AND RESULTS

Inhalation of 18 ppm NO reduced the mean (+/- SE) pulmonary artery pressure (PAP) from 33 +/- 2 to 28 +/- 1 mmHg (p = 0.008), increased right ventricular ejection fraction (RVEF), as assessed by thermodilution technique, from 28 +/- 2 to 32 +/- 2% (p = 0.005), decreased right ventricular end-diastolic volume index from 114 +/- 6 to 103 +/- 8 ml.m-2 (p = 0.005) and right ventricular end-systolic volume index from 82 +/- 4 to 70 +/- 5 ml.m-2 (p = 0.009). Mean arterial pressure (MAP) and cardiac index (CI) did not change significantly. The effects of 36 ppm NO were not different from the effects of 18 ppm NO. Infusion of PGI2 reduced PAP from 34 +/- 2 to 30 +/- 2 mmHg (p = 0.02), increased RVEF from 29 +/- 2 to 32 +/- 2% (p = 0.02). Right ventricular end-diastolic and end-systolic volume indices did not change significantly. MAP decreased from 80 +/- 4 to 70 +/- 5 mmHg (p = 0.03), and CI increased from 4.0 +/- 0.5 to 4.5 +/- 0.5 l.min-1.m-2 (p = 0.02).

CONCLUSIONS

Using a new approach to selective pulmonary vasodilation by inhalation of NO, we demonstrate in this group of ARDS patients that an increase in RVEF is not necessarily associated with a rise in CI. The increase in CI during PGI2 infusion is probably related to the systemic effect of this substance.

Influence of positioning on ventilation-perfusion relationships in severe adult respiratory distress syndrome

In 12 patients with severe adult respiratory distress syndrome (ARDS), pulmonary gas exchange and hemodynamics were evaluated before, during, and after a 2-h period of pressure-controlled mechanical ventilation with the patient in the prone position. Ventilation-perfusion relationships (VA/Q) were assessed by a multiple inert gas elimination technique. Pressure-controlled mechanical ventilation in the prone position resulted in an overall increase (p < or = 0.05) of arterial oxygenation after 120 min (98.4 +/- 50.3 to 146.2 +/- 94.9 mm Hg). Whereas eight patients revealed an improvement of PaO2 of more than 10 mm Hg after 30 min in the prone position (responders), four patients reacted to positional changes with a deterioration of arterial oxygenation (nonresponders). Data about the continuous distribution of ventilation-perfusion ratios revealed that in the responder group positioning caused a decrease of shunt perfusion of 11 +/- 5% and a concomitant increase of normal VA/Q by 12 +/- 4% after 30 min. There was no change demonstrable within low VA/Q areas. Returning the patient to the supine position reversed the improvement in gas exchange. The nonresponder group did not show any significant alteration in the distribution of VA/Q during the study. We concluded that improvement of oxygenation during pressure-controlled mechanical ventilation in the prone position is due to a shift of blood flow away from shunt regions, thus increasing areas with normal VA/Q. This redistribution of blood flow is most likely caused by a recruitment of previously ateletatic but nondiseased areas induced by altered gravitational forces.

Bacterial and fungal colonization and infections using oral selective bowel decontamination in orthotopic liver transplantations

Bacterial and fungal infections are a major cause of morbidity and mortality after orthotopic liver transplantation. In the immunocompromised host, infections are thought to arise from the gut, which is almost always colonized with potential pathogens. Using oral selective bowel decontamination (SBD), potential pathogens can be eradicated from the gut and infections prevented. In this catamnestic study we have reviewed gastrointestinal colonization, bacterial and fungal infections, and bacterial resistance to standard antibiotics in our first 206 liver transplant patients while under SBD. With few exceptions, gram-negatives were eradicated from the gastrointestinal tract and secondary colonization was inhibited. In spite of unsatisfactory elimination of Candida, probably because nystatin doses were too low, Candida infections were rare (n = 4) and none was fatal. One and two-year survival rates were 93% and 92%, respectively. The bacterial and fungal infection rate was 27.8% with an infection-related mortality of 1.95%. Infections with aerobic gram-positive bacteria prevailed and only 11 gram-negative and 11 fungal infections occurred; among the latter, Aspergillus and Mucor were the most serious and responsible for three of the six deaths in this series. With regard to the development of resistance, we found an increasing number of enterococci and coagulase-negative staphylococci resistant to ciprofloxacin and imipenem, respectively, but unlikely as a consequence of SBD.

[Therapy of ARDS. 1. Current therapeutic strategy including extracorporeal gas exchange]

Recent studies and reviews continue to report a high mortality associated with the acute respiratory distress syndrome (ARDS), which involves a severe inflammatory reaction within the whole lung that is frequently associated with multiple-organ failure. Important factors contributing to the poor results in severe ARDS are the aggressive procedures required to maintain sufficient arterial oxygenation, such as mechanical ventilation with high inspiratory pressures and high inspired oxygen concentrations (FiO2) which themselves contribute to the progression of the disease. As no specific therapy that reduces or prevents the general inflammatory reaction is known, current therapy is limited to procedures that minimize peak inspiratory pressures and FiO2. Therefore, pressure- and volume-limited ventilation modes with positive end-expiratory pressure, controlled hypercapnia, differential lung ventilation when appropriate, positioning (particularly prone), and aggressive dehydration are used. Should these procedures fail to improve arterial gas exchange, the patients may be additionally treated by veno-venous extracorporeal gas exchange. To reduce the risk of severe haemorrhagic complications due to high levels of systemic heparinization, systems internally coated with covalently bound heparin, which allow a lower level of systemic anticoagulation, should be used. From April 1989 to August 1993, 89 patients were transferred to our intensive care unit for treatment of severe ARDS; 52 were treated by combining the described conventional methods without artificial gas exchange (survival rate 88%) and 37 additionally underwent artificial gas exchange (survival rate 57%). The overall survival rate was 75%. On the basis of these experiences, we conclude that this step-by-step approach may improve survival in patients with severe ARDS.

Bacterial and fungal colonization and infections using oral selective bowel decontamination in orthotopic liver transplantations

Bacterial and fungal infections are a major cause of morbidity and mortality after orthotopic liver transplantation. In the immunocompromised host, infections are thought to arise from the gut, which is almost always colonized with potential pathogens. Using oral selective bowel decontamination (SBD), potential pathogens can be eradicated from the gut and infections prevented. In this catamnestic study we have reviewed gastrointestinal colonization, bacterial and fungal infections, and bacterial resistance to standard antibiotics in our first 206 liver transplant patients while under SBD. With few exceptions, gram-negatives were eradicated from the gastrointestinal tract and secondary colonization was inhibited. In spite of unsatisfactory elimination of Candida, probably because nystatin doses were too low, Candida infections were rare (n = 4) and none was fatal. One and two-year survival rates were 93% and 92%, respectively. The bacterial and fungal infection rate was 27.8% with an infection-related mortality of 1.95%. Infections with aerobic gram-positive bacteria prevailed and only 11 gram-negative and 11 fungal infections occurred; among the latter, Aspergillus and Mucor were the most serious and responsible for three of the six deaths in this series. With regard to the development of resistance, we found an increasing number of enterococci and coagulase-negative staphylococci resistant to ciprofloxacin and imipenem, respectively, but unlikely as a consequence of SBD.

Smoking cessation methods: recommendations for health professionals. Advisory Group of the European School of Oncology

Smoking is the leading preventable cause of death. Approximately 40% of Europeans now smoke. Many smokers want to stop but do not make the attempt, and of those who try, most are unsuccessful. Primary care health providers can help their patients to stop by using brief behavioural and pharmacological interventions. Specialised smoking cessation clinics can support selected patients referred by primary care providers. This report reviews intervention techniques for health care providers, which, in combination with effective legislative and educational interventions, can significantly reduce the prevalence of smoking.

[Non-drug aid to tobacco withdrawal]

The smokers who receive the interventions that have often been the source of information in the literature about smoking cessation represent about 4% of the population of smokers: volunteers and help-seekers. This population is not representative of the smokers seen by their doctors; smoking patients can be at any of the stages in their smoking career. But doctors can play an important role in facilitating a smokers's progression towards smoking cessation by a clear, consistent and unequivocable message not to smoke. Depending on the time available and patient desire, doctors can call upon strategies from techniques developed in cessation clinics. The number of contacts with the smoking patient to provide these strategies is the most important factor in the aid the doctor can provide.

Inhaled nitric oxide for the adult respiratory distress syndrome

BACKGROUND

The adult respiratory distress syndrome is characterized by pulmonary hypertension and right-to-left shunting of venous blood. We investigated whether inhaling nitric oxide gas would cause selective vasodilation of ventilated lung regions, thereby reducing pulmonary hypertension and improving gas exchange.

METHODS

Nine of 10 consecutive patients with severe adult respiratory distress syndrome inhaled nitric oxide in two concentrations for 40 minutes each. Hemodynamic variables, gas exchange, and ventilation-perfusion distributions were measured by means of multiple inert-gas-elimination techniques during nitric oxide inhalation; the results were compared with those obtained during intravenous infusion of prostacyclin. Seven patients were treated with continuous inhalation of nitric oxide in a concentration of 5 to 20 parts per million (ppm) for 3 to 53 days.

RESULTS

Inhalation of nitric oxide in a concentration of 18 ppm reduced the mean (+/- SE) pulmonary-artery pressure from 37 +/- 3 mm Hg to 30 +/- 2 mm Hg (P = 0.008) and decreased intrapulmonary shunting from 36 +/- 5 percent to 31 +/- 5 percent (P = 0.028). The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2), an index of the efficiency of arterial oxygenation, increased during nitric oxide administration from 152 +/- 15 mm Hg to 199 +/- 23 mm Hg (P = 0.008), although the mean arterial pressure and cardiac output were unchanged. Infusion of prostacyclin reduced pulmonary-artery pressure but increased intrapulmonary shunting and reduced the PaO2/FiO2 and systemic arterial pressure. Continuous nitric oxide inhalation consistently lowered the pulmonary-artery pressure and augmented the PaO2/FiO2 for 3 to 53 days.

CONCLUSIONS

Inhalation of nitric oxide by patients with severe adult respiratory distress syndrome reduces the pulmonary-artery pressure and increases arterial oxygenation by improving the matching of ventilation with perfusion, without producing systemic vasodilation. Randomized, blinded trials will be required to determine whether inhaled nitric oxide will improve outcome.

Anti-tobacco measures in the world: the French case

The devastating long-term effects of tobacco smoking registered in the developed world and now imminent in the developing world must be responded to on national and international levels. In France, governmental tobacco control action began in 1976. Despite the high rates of premature mortality among men and women, legislative controls that were introduced were not enforced. Over the past decade, overall smoking prevalence has remained stable, reflecting growth in women's rates which compensates declines in men's rates. Comprehensive tobacco control measures should include prohibiting tobacco advertising, real tobacco retail price increases and regulations protecting non-smokers in public places. New legislation was voted in 1991 both in France and in the European Community. These measures, reinforced by a framework of continuing public education, may be an important step towards effective health promotion.

Major thoracic surgery during long-term extracorporeal lung assist for treatment of severe adult respiratory distress syndrome (ARDS)

Surgery in patients treated with extracorporeal lung assist (ELA) carries a high risk of life threatening bleeding complications caused by the need for systemic anticoagulation. A case report describing a successful surgical intervention for the repair of a broncho-pleural leakage by thoracotomy during ELA is presented. A newly developed heparin coated extracorporeal system was used in a patient being treated for severe adult respiratory distress syndrome (ARDS) after left sided pneumectomy. The heparin coated system allowed discontinuation of systemic heparinization intraoperatively without coagulation complications related to the extracorporeal system. This procedure was followed by resolution of the ARDS.

Extracorporeal lung assist with heparin-coated systems

Extracorporeal lung assist (ELA) has been recommended for the treatment of ARDS if conventional therapy fails. However, the need for nearly complete anticoagulation is a major risk factor for hemorrhagic complications. We describe our experience with 13 ARDS patients treated with ELA using heparin-coated systems (Carmeda). Maintaining partial thromboplastin time and activated clotting time within or close to the normal range, even major surgery (20 thoracotomies and 2 laparotomies) could be performed without undue bleeding complications related to anticoagulation during extracorporeal support. Eight of the 13 patients survived. The use of heparin-coated systems allows prolonged ELA with nearly physiological coagulation function, permitting major surgical intervention. It enhances the safety margin of extracorporeal gas exchange and may ultimately extend its indications.