A prognostic model for the prediction of survival in cystic fibrosis

A screening tool to identify risk for bronchiectasis progression in children with cystic fibrosis

BACKGROUND

The marked heterogeneity in cystic fibrosis (CF) disease complicates the selection of those most likely to benefit from existing or emergent treatments.

OBJECTIVE

We aimed to predict the progression of bronchiectasis in preschool children with CF.

METHODS

Using data collected up to 3 years of age, in the Australian Respiratory Early Surveillance Team for CF cohort study, clinical information, chest computed tomography (CT) scores, and biomarkers from bronchoalveolar lavage were assessed in a multivariable linear regression model as predictors for CT bronchiectasis at age 5-6.

RESULTS

Follow-up at 5-6 years was available in 171 children. Bronchiectasis prevalence at 5-6 was 134/171 (78%) and median bronchiectasis score was 3 (range 0-12). The internally validated multivariate model retained eight independent predictors accounting for 37% (adjusted R² ) of the variance in bronchiectasis score. The strongest predictors of future bronchiectasis were: pancreatic insufficiency, repeated intravenous treatment courses, recurrent lower respiratory infections in the first 3 years of life, and lower airway inflammation. Dichotomizing the resulting prediction score at a bronchiectasis score of above the median resulted in a diagnostic odds ratio of 13 (95% confidence interval [CI], 6.3-27) with positive and negative predictive values of 80% (95% CI, 72%-86%) and 77% (95% CI, 69%-83%), respectively.

CONCLUSION

Early assessment of bronchiectasis risk in children with CF is feasible with reasonable precision at a group level, which can assist in high-risk patient selection for interventional trials. The unexplained variability in disease progression at individual patient levels remains high, limiting the use of this model as a clinical prediction tool.

The impact of liver disease on mortality in cystic fibrosis-A systematic review

BACKGROUND

There is conflicting evidence on the impact of liver disease (CFLD) on life expectancy in CF. Therefore the aim of this systematic review was to evaluate the impact of liver disease (CFLD) on mortality in CF.

METHODS

The protocol was published at (https://hrbopenresearch.org/articles/3-44/v3) using PRISPMA-P guidelines and registered in Prospero 2020 (CRD42020182885). Three databases were searched for publications (1938-2020) where the outcome was all-cause mortality (defined as death and transplantation) or CF-specific mortality in participants with CFLD. Studies with and without a comparator group were included. Studies were divided into 2 groups based on the definition of CFLD: Group 1 used 2 categories of liver disease (i) liver disease with portal hypertension (PH) (ii) non-specific abnormalities which did not meet the criteria for PH, Group 2 studies only included participants with PH.

RESULTS

All 14 eligible studies were observational, with a moderate-high risk of bias, Six of the 14 studies directly compared mortality between those with CFLD and those with no liver disease, and 5/6 demonstrated that those with CFLD had at least 3 time the risk of death compared to those with no liver disease. Pulmonary complications were the primary cause of death.

CONCLUSION

This SR demonstrates that liver disease shortens life expectancy in CF, and that pulmonary complications are the primary cause of death in those with CFLD. There has been no improvement in survival for persons with CFLD despite significant improvements in life expectancy for persons with CF who have no evidence of liver disease.

Cardiorespiratory fitness on a treadmill in an adult cystic fibrosis population

Objectives

(1) To describe the cardiorespiratory fitness (CRF) in an adult cystic fibrosis population related to sex and age, (2) to evaluate the cause of low CRF and (3) to study the association between peak oxygen uptake (VO2peak) and forced expiratory volume in 1 s (FEV1).

Methods

A total of 204 cardiopulmonary treadmill exercise tests (CPETs) performed by 116 patients were included. VO2peak, gas exchange, heart rate, oxygen saturation and ventilatory variables were measured.

A low CRF was defined as a VO2peak <80% of predicted, ventilatory limitation was defined as a breathing reserve <15%, exercise hypoxaemia was defined as an oxygen saturation <88% and ventilation-perfusion mismatch was defined as a minute ventilation/ventilatory equivalent for carbon dioxide slope ≥34. In patients who had performed three or more CPETs, the annual change in FEV1 and VO2peak were calculated using linear regression.

Results

The VO2peak was 40.6±11.5 and 35.2±8.9 mL kg−1 min−1, which was 87±23 and 93±20 in percentage of predicted for men and women, respectively. VO2peak was moderately affected by age, for men (r=−0.36, p<0.001) and women (r=−0.53, p<0.001), respectively. In 45 of 101 tests where CRF was low, no cardiorespiratory limiting factors were identified. The correlation coefficient between VO2peak and FEV1 was r=0.64 (p<0.001). In participants with a low CRF, FEV1 ranged from 20% to 112% of predicted.

Conclusions

The correlation between VO2peak and FEV1 was moderate. The majority of the tests resulted in a VO2peak within normal limits. Interestingly, 44% of the tests with a low VO2peak could be explained by deconditioning. Thus, exercise therapy may be beneficial for these patients.

Dynamic Prediction of Survival in Cystic Fibrosis: A Landmarking Analysis Using UK Patient Registry Data

BACKGROUND

Cystic fibrosis (CF) is an inherited, chronic, progressive condition affecting around 10,000 individuals in the United Kingdom and over 70,000 worldwide. Survival in CF has improved considerably over recent decades, and it is important to provide up-to-date information on patient prognosis.

METHODS

The UK Cystic Fibrosis Registry is a secure centralized database, which collects annual data on almost all CF patients in the United Kingdom. Data from 43,592 annual records from 2005 to 2015 on 6181 individuals were used to develop a dynamic survival prediction model that provides personalized estimates of survival probabilities given a patient's current health status using 16 predictors. We developed the model using the landmarking approach, giving predicted survival curves up to 10 years from 18 to 50 years of age. We compared several models using cross-validation.

RESULTS

The final model has good discrimination (C-indexes: 0.873, 0.843, and 0.804 for 2-, 5-, and 10-year survival prediction) and low prediction error (Brier scores: 0.036, 0.076, and 0.133). It identifies individuals at low and high risk of short- and long-term mortality based on their current status. For patients 20 years of age during 2013-2015, for example, over 80% had a greater than 95% probability of 2-year survival and 40% were predicted to survive 10 years or more.

CONCLUSIONS

Dynamic personalized prediction models can guide treatment decisions and provide personalized information for patients. Our application illustrates the utility of the landmarking approach for making the best use of longitudinal and survival data and shows how models can be defined and compared in terms of predictive performance.

Predicting disease progression in cystic fibrosis

INTRODUCTION

Progressive lung disease is the major cause of morbidity and mortality in patients with cystic fibrosis (CF). Methods of correctly predicting the future progression of lung disease in patients with CF are essential for directing aggressive treatment to prevent loss of lung function and end stage respiratory failure. Areas covered: This review addresses predictors of respiratory disease progression in patients with CF. We searched Web of Science and Medline, with no restriction on publication date, with the search terms 'cystic fibrosis' and 'disease progression', 'lung function decline', 'prognosis', 'prediction/predictive', 'prediction/prognostic scores', 'risk factors', 'outcome measures/endpoints/disease surrogate', 'longitudinal/long term', 'statistical model', and 'survival'. Expert commentary: Forced expiratory volume in 1 sec (FEV₁) and rate of FEV₁ decline, remain the most significant predictors of mortality in patients with CF while CT scores and airway secretion biomarkers are the main predictors of early CF lung disease. Comprehensive scores incorporating clinical, lung function, imaging and laboratory data will become essential in the future for predicting disease progression and for use in clinical trials. Early interventions may delay the progression of structural lung disease.

Prognostication and Risk Factors for Cystic Fibrosis via Automated Machine Learning

Accurate prediction of survival for cystic fibrosis (CF) patients is instrumental in establishing the optimal timing for referring patients with terminal respiratory failure for lung transplantation (LT). Current practice considers referring patients for LT evaluation once the forced expiratory volume (FEV1) drops below 30% of its predicted nominal value. While FEV1 is indeed a strong predictor of CF-related mortality, we hypothesized that the survival behavior of CF patients exhibits a lot more heterogeneity. To this end, we developed an algorithmic framework, which we call AutoPrognosis, that leverages the power of machine learning to automate the process of constructing clinical prognostic models, and used it to build a prognostic model for CF using data from a contemporary cohort that involved 99% of the CF population in the UK. AutoPrognosis uses Bayesian optimization techniques to automate the process of configuring ensembles of machine learning pipelines, which involve imputation, feature processing, classification and calibration algorithms. Because it is automated, it can be used by clinical researchers to build prognostic models without the need for in-depth knowledge of machine learning. Our experiments revealed that the accuracy of the model learned by AutoPrognosis is superior to that of existing guidelines and other competing models.

A 3-year prognostic score for adults with cystic fibrosis

BACKGROUND

Therapeutic progress in patients with cystic fibrosis (CF) has resulted in improved prognosis over the past decades. We aim to reevaluate prognostic factors of CF and provide a prognostic score to predict the risk of death or lung transplantation (LT) within a 3-year period in adult patients.

METHODS

We developed a logistic model using data from the French CF Registry and combined the coefficients into a prognostic score. The discriminative abilities of the model and the prognostic score were assessed by c-statistic. The prognostic score was validated using a 10-fold cross-validation.

RESULTS

The risk of death or LT within 3years was related to eight characteristics. The development and the validation provided excellent results for the prognostic score; the c-statistic was 0.91 and 0.90 respectively.

CONCLUSION

The score developed to predict 3-year death or LT in adults with CF might be useful for clinicians to identify patients requiring specialized evaluation for LT.

Use of FEV1 in cystic fibrosis epidemiologic studies and clinical trials: A statistical perspective for the clinical researcher

BACKGROUND

Forced expiratory volume in 1s (FEV₁) is an established marker of cystic fibrosis (CF) disease progression that is used to capture clinical course and evaluate therapeutic efficacy. The research community has established FEV₁ surveillance data through a variety of observational data sources such as patient registries, and there is a growing pipeline of new CF therapies demonstrated to be efficacious in clinical trials by establishing improvements in FEV₁.

RESULTS

In this review, we summarize from a statistical perspective the clinical relevance of FEV₁ based on its association with morbidity and mortality in CF, its role in epidemiologic studies of disease progression and comparative effectiveness, and its utility in clinical trials. In addition, we identify opportunities to advance epidemiologic research and the clinical development pipeline through further statistical considerations.

CONCLUSIONS

Our understanding of CF disease course, therapeutics, and clinical care has evolved immensely in the past decades, in large part due to the thoughtful application of rigorous research methods and meaningful clinical endpoints such as FEV₁. A continued commitment to conduct research that minimizes the potential for bias, maximizes the limited patient population, and harmonizes approaches to FEV₁ analysis while maintaining clinical relevance, will facilitate further opportunities to advance CF care.

Exercise responses are related to structural lung damage in CF pulmonary disease

INTRODUCTION

Early detection of lung disease is a primary objective in monitoring patients with Cystic Fibrosis (CF); High-Resolution-Computed-Tomography (HRCT) assesses structural damage. Spirometry and cardiopulmonary exercise testing are used for functional evaluation of CF lung disease.

AIM

To evaluate the deterioration of exercise testing parameters over a 2-year period compared to the change of spirometry and HRCT parameters among CF patients.

METHODS

Twenty-eight CF patients were evaluated with HRCT, spirometry, and exercise testing; 15 had two assessments with an interval of 2 years. Correlation analyses between Bhalla score parameters and functional measures were performed.

RESULTS

Twenty-eight patients with CF (mean age 14.9 years, mean forced expiratory volume in 1 sec [FEV1 ] 83.2%) were evaluated. FEV1 was not found to change significantly in the 2-year period (P = 0.612). Both mean Bhalla score and mean peak oxygen consumption (VO2 peak %) deteriorated significantly (P = 0.014 and P = 0.026, respectively). VO2 peak and respiratory equivalents for O2 and CO2 at peak exercise were found to be significant predictors of Bhalla score (r = -0.477, P = 0.010; r = 0.461, P = 0.018; r = 0.402; P = 0.042, respectively). Anaerobic threshold was associated with changes in Bhalla score over the following 2 years.

CONCLUSIONS

Exercise testing is more sensitive than spirometry to detect structural changes in CF lungs. Pediatr Pulmonol. 2016; 51:914-920. © 2016 Wiley Periodicals, Inc.

Use of lung clearance index to assess the response to intravenous treatment in cystic fibrosis

BACKGROUND

Progressive lung disease is the main cause of clinical deterioration and mortality in cystic fibrosis (CF) patients. Being able to assess the effectiveness of interventions is very significant.

OBJECTIVES

To assess the response to intravenous (IV) treatment among CF patients, using forced expired volume in 1(st) second (FEV1) and Lung Clearance Index (LCI) as outcome measures and to compare the effect of IV treatment on lung function and LCI between CF children being treated on a regular basis, or in case of a pulmonary exacerbation.

SUBJECTS AND METHODS

Thirty-two CF patients (15 males) with mean age 9.90 (range: 2-23) years, performed spirometry and multiple breath washout (MBW) before and one month after IV antibiotic treatment. Nineteen patients received a course of elective treatment (group A) and 13 received IV antibiotic regimens for an acute exacerbation (group B).

RESULTS

Statistically significant differences after treatment were seen in LCI (p≤0.001), and Forced Expiratory Flow (FEF) z-scores (p<0.05). FEV1 did not change significantly after drug intervention. Dividing patients into two groups, only LCI showed significant change (p<0.05), when treatment was administered on a regular basis. Patients being treated for an acute pulmonary exacerbation showed significant improvement in most of the lung function parameters: LCI (p=0.0001), FEV1% (p=0.05), FEV1 z-score (p=0.033) and FEF25-75 (p=0.046). The mean LCI difference was significantly greater in group B compared to group A (p=0.001).

CONCLUSION

LCI is more sensitive marker than FEV1 to assess the effect of IV antibiotic treatment among CF children. IV antibiotics are more effective on lung function parameters, when they are administered for an acute exacerbation, than when they are given on a regular basis. Hippokratia 2015, 19 (1): 47-52.

Putting lung function and physiology into perspective: cystic fibrosis in adults

Adult cystic fibrosis (CF) is notable for the wide heterogeneity in severity of disease expression, both between patients and within the lungs of individuals. Although CF airways disease appears to start in the small airways, in adults there is typically widespread bronchiectasis, increased airway secretions, and extensive obstruction and inflammation of the small airways. The complexity and heterogeneity of airways disease in CF means that although there are many different methods of assessing and describing lung 'function', none of these single-dimensional tests is able to provide a comprehensive assessment of lung physiology across the spectrum seen in adult CF. The most widely described measure, the forced expiratory volume in 1 s, remains a useful and simple clinical tool, but is insensitive to early changes and may be dissociated from other more detailed assessments of disease severity such as computed tomography. In this review, we also discuss the use of more sensitive novel assessments such as multiple breath washout tests and impulse oscillometry, as well as the role of cardiopulmonary exercise testing. In the future, hyperpolarized gas magnetic resonance imaging techniques that combine regional structural and functional information may help us to better understand these measures, their applications and limitations.

Interpretation of lung function in infants and young children with cystic fibrosis

The last decade has seen a significant advance in understanding about early lung disease in cystic fibrosis (CF). As studies that have measured lung function in preschool years are conducted in association with surveillance of infection, inflammation and early structural changes, and emerging longitudinal data become available, a better insight into the very early onset and nature of such lung disease is emerging. Interventions during the preschool years are increasingly viewed as being crucial to delaying and minimizing disease progression as this is the most important period of postnatal life in terms of lung development and airway remodelling. Lung function measurement in CF is potentially an important assessment tool and is used in routine clinical practice in several centres already. Results of studies from lung function tests that, on the basis of their underpinning physiology, are viewed as being best suited currently for the early detection of lung disease in CF are reviewed.

Reduced mortality in cystic fibrosis patients treated with tobramycin inhalation solution

BACKGROUND

Though tobramycin inhalation solution has been used for over a decade to improve lung function and reduce exacerbations in patients with cystic fibrosis (CF), its effects on mortality have not been well-described. This study aimed to assess the association between use of tobramycin inhaled solution and mortality in patients with CF and chronic Pseudomonas aeruginosa (PA) infection.

METHODS

Longitudinal logistic regression was used to assess the association between current-year reported use of tobramycin inhalation solution and subsequent-year mortality of patients meeting recommended criteria for tobramycin inhalation solution use in the United States Cystic Fibrosis Foundation's Patient Registry (1996-2008).

RESULTS

Among 12,740 patients meeting inclusion criteria, 2,538 deaths were observed during a median follow-up of 6 years. After regression adjustment, use of tobramycin inhaled solution was associated with a 21% reduction in the odds of subsequent year mortality (odds ratio (95% CI): 0.79 (0.72-0.88), P < 0.001). In our model, use of dornase alfa was also associated with a 15% reduction in the odds of subsequent year mortality (odds ratio (95% CI): 0.85 (0.76-0.95), P = 0.005). Underweight for age, CF-related diabetes, female gender, worse lung function and cultures positive for Pseudomonas aeruginosa or Burkholderia cepacia complex, among multiple other patient characteristics, were associated with significantly increased mortality. Adjusted mortality rates for patients reporting tobramycin inhalation solution use in all versus none of the follow-up years were 1.3% versus 2.1% at 2 years, 5.2% versus 8.0% at 5 years, and 9.9% versus 15.0% at 10 years.

CONCLUSION

After adjustment for multiple patient characteristics and known risk factors, use of tobramycin inhalation solution was associated with significantly reduced mortality among patients with CF.

Liver disease in adult patients with cystic fibrosis: a frequent and independent prognostic factor associated with death or lung transplantation

BACKGROUND & AIMS

Increased life expectancy in patients with cystic fibrosis (CF) allows better knowledge of non-pulmonary complications like liver disease (CFLD). However, few data have been published in large adult cohorts. The aim of this study was to estimate the prevalence and the prognosis of CFLD in adult CF patients.

METHODS

A retrospective analysis of a monocentric cohort of adult CF patients prospectively followed, at least every year, was performed. CFLD was diagnosed using published composite criteria. If cirrhosis was suspected, upper digestive endoscopy was realized to assess the presence of portal hypertension.

RESULTS

A cohort of 285 adult CF patients was followed during 4.8 ± 3.6 years. Among them, 90 had CFLD at the beginning of follow-up and 23 a suspicion of cirrhosis. Factors independently associated with liver disease at baseline were history of meconium ileus, pancreatic insufficiency, chronic colonization with Burkholderia cepacia and the number of IV antibiotic courses per year. Nine patients developed liver decompensation during follow-up, all with a suspicion of cirrhosis at baseline. Six patients underwent liver transplantation alone and three patients combined liver and lung transplantation. Factors independently associated with death or lung transplantation at baseline were liver disease, BMI, forced expiratory volume in 1 second and number of IV antibiotic courses per year.

CONCLUSIONS

CFLD was present at baseline in one third of adult patients with CF with a marked risk of liver decompensation during follow-up. Moreover, CFLD at baseline appears as an independent factor associated with death or lung transplantation.

Association between nutritional status and dietary intake in patients with cystic fibrosis

OBJECTIVE

To determine the relationship between nutritional status and dietary intake in patients with cystic fibrosis.

METHODS

Cross-sectional study involving 85 cystic fibrosis patients between 6 and 18 years of age. Dietary intake was evaluated by the 3-day diet record (weighing the food consumed). The outcome measures were the following nutritional status indicators: weight/height (W/H%) percentage, body mass index (BMI) percentiles, Z score for weight/age (W/A), Z score for height/age (H/A) and percentage of dietary intake compared with the Recommended Dietary Allowance (RDA).

RESULTS

The prevalence of well-nourished patients was 77.7%, using BMI above the 25th percentile as the cut-off value, and the W/H% was above 90% in 83.5%. The mean dietary intake, evaluated in 82 patients, was 124.5% of the RDA. In the univariate logistic regression analyses, we found a significant association between the independent variable calorie intake and the Z score for W/A. The multivariate analysis, based on the Z score for H/A and adjusted for FEV1, methicillin-resistant Staphylococcus aureus colonization and number of hospitalizations, demonstrated that a 1% increase in the calorie intake decreases the chance of having short stature by 2% (OR: 0.98; 95% CI: 0.96-1.00). Maternal level of education showed a borderline association (p = 0.054).

CONCLUSIONS

The prevalence of malnutrition was low in this sample of patients. The study model demonstrated an association between dietary intake and nutritional status. Dietary intake was a predictive factor of statural growth in patients with cystic fibrosis.

The relationship of clinical and inflammatory markers to outcome in stable patients with cystic fibrosis

Decreased survival in patients with cystic fibrosis has been related to FEV1, BMI, and infection with Burkholderia cepacia complex (BCC). We have assessed the relationship of blood, sputum, and urine inflammatory markers to lung function, BMI, colonization with B cenocepacia (Bc), and patient survival. Thirty-nine stable cystic fibrosis (CF) patients (10 with Bc) were enrolled in a study to determine the effect of alpha-1-antitrypsin on airways inflammation. Pre-treatment measurements were used in this study. Demographics, sputum microbiology, heart rate, oxygen saturation, lung function were recorded. Blood samples were obtained for white blood count (WBC), C-Reactive Protein (CRP), and plasma neutrophil elastase/AAT complexes (pNEC). Neutrophil elastase (NE), neutrophil elastase/AAT complexes (sNEC), interleukin-8 (IL-8), TNF-receptor 1 (sTNFr), and myeloperoxidase (MPO) were measured in sputum and urinary desmosine concentration determined. Patients with Bc had significantly higher levels of pNEC, 332 +/- 91.4 ng/ml (mean +/- SEM) versus 106 +/- 18.2 ng/ml (P = 0.0005) and sNEC, 369 +/- 76.6 ng/ml versus 197 +/- 36.0 ng/ml compared to those who were not. Five deaths were reported at the end of 1 year, (four with Bc) (P = 0.011). Patients who subsequently died had significantly lower lung function FEV1, 1.2 +/- 0.2 L versus 2.0 +/- 0.1 L (P = 0.03) and FVC, 2 +/- 0.3 L versus 3.1 +/- 0.2 L (P = 0.01), compared to those that survived. There was significantly higher NE activity, 3.6 +/- 1.6 U/ml versus 1.5 +/- 0.6 U/ml (P = 0.03), pNEC, 274 +/- 99 ng/ml versus 142 +/- 30 ng/ml (P = 0.05), MPO, 163 +/- 62 mcg/ml versus 54 +/- 6.9 mcg/ml (P = 0.03), and urinary desmosines 108 +/- 19.9 pM/mg creatinine versus 51.1 +/- 3.3 pM/mg creatinine (P = 0.001), in those patients who subsequently died compared to those that survived. These data suggest there is increased neutrophil degranulation in patients infected with Bc and these patients have a poor outcome.

High-resolution computed tomography (HRCT) should not be considered as a routine assessment method in cystic fibrosis lung disease

High-resolution computed tomography (HRCT) scanning of the chest should not be considered a routine clinical investigation in the management of CF. Although it demonstrates the detection of early lung damage in children with cystic fibrosis (CF), before HRCT can be considered for routine clinical use in CF it needs to be shown that the benefit from the information obtained will out-weigh potential risks. There is insufficient evidence for the benefit of HRCT for its inclusion into routine care. Moreover, in the absence of information resulting in change in management, HRCT has the potential to increase anxiety for both clinicians and families. In order to advocate for incorporating this technology into routine CF care, further support for its role in management decisions is needed.

Determinants of mortality for adults with cystic fibrosis admitted in Intensive Care Unit: a multicenter study

BACKGROUND

Intensive care unit (ICU) admission of adults with cystic fibrosis (CF) is controversial because of poor outcome. This appraisal needs re-evaluation following recent changes in both CF management and ICU daily practice. Objectives were to determine long-term outcome of adults with CF admitted in ICU and to identify prognostic factors.

METHODS

Retrospective multicenter study of 60 ICU hospitalizations for 42 adult CF patients admitted between 2000 and 2003. Reason for ICU admission, ventilatory support provided and one-year survival were recorded. Multiple logistic analysis was used to determine predictors of mortality.

RESULTS

Prior to ICU admission, all patients (mean age 28.1 +/- 8 yr) had a severe lung disease (mean FEV1 28 +/- 12% predicted; mean PaCO2 47 +/- 9 mmHg). Main reason for ICU hospitalization was pulmonary infective exacerbation (40/60). At admission, noninvasive ventilation was used in 57% of cases and was successful in 67% of patients. Endotracheal intubation was implemented in 19 episodes. Overall ICU mortality rate was 14%. One year after ICU discharge, 10 of the 28 survivors have been lung transplanted. Among recognized markers of CF disease severity, only the annual FEV1 loss was associated with a poor outcome (HR = 1.47 [1.18-1.85], p = 0.001). SAPSII (HR = 1.08 [1.03-1.12], p < 0.001) and endotracheal intubation (HR = 16.60 [4.35-63.34], p < 0.001) were identified as strong independent predictors of mortality.

CONCLUSION

Despite advanced lung disease, adult patients with CF admitted in ICU have high survival rate. Endotracheal intubation is associated with a poor prognosis and should be used as the last alternative. Although efforts have to be made in selecting patients with CF likely to benefit from ICU resources, ICU admission of these patients should be considered.

Risk factors for death of patients with cystic fibrosis awaiting lung transplantation

RATIONALE

The optimal timing for listing of cystic fibrosis patients for lung transplantation is controversial.

OBJECTIVES

We conducted a retrospective cohort study of 343 patients listed for lung transplantation at four academic medical centers to identify risk factors for death while awaiting transplantation.

METHODS

Data on possible risk factors were abstracted from medical records.

MEASUREMENTS

Time to death, patient demographic characteristics, and risk factors for death while awaiting transplantation were assessed. Univariate and multivariate survival analyses were performed using Cox regression.

RESULTS

By univariate analyses, FEV1 < or = 30% predicted (HR, 3.8; 95% CI, 2.0-7.5), Pa(CO2) > or = 50 mm Hg (HR, 1.85; 95% CI, 1.1-3.0), and shorter height (HR, 1.8; 95% CI, 1.1-3.0) were associated with a higher risk of death. Referral from an accredited cystic fibrosis center was associated with a lower risk (HR, 0.53; 95% CI, 0.30-0.92). The final multivariate model included referral from an accredited cystic fibrosis center (HR, 0.5; 95% CI, 0.3-1.0) and listing year after 1996 (HR, 0.4; 95% CI, 0.2-0.7); both were associated with a lower risk of death. FEV1 < or = 30% predicted (HR, 6.8; 95% CI, 2.4-19.3), Pa(CO2) > or = 50 mm Hg (HR, 6.9; 95% CI, 1.5-32.1), and use of a nutritional intervention (HR, 2.3; 95% CI, 1.3-4.1) were associated with increased risk. Patients with FEV1 > 30% predicted had a higher risk of death only when their Pa(CO2) was > or = 50 mm Hg (HR, 7.0; 95% CI, 1.5-32), while the increased risk of death with FEV1 < or = 30% was not further influenced by the presence of hypercapnia.

CONCLUSIONS

We identified risk factors for waiting list mortality that could impact on transplant listing and allocation guidelines.

Balancing benefits and risks for cystic fibrosis newborn screening: implications for policy decisions

Policy decisions for newborn screening (NBS) are particularly challenging when the balance of benefits and risks is not tipped dramatically in 1 direction. When this is the case, as with cystic fibrosis (CF), the traditional approach of mandatory testing of all newborns in all states may not be appropriate. Alternative approaches may produce a substantial reduction in psychosocial risks, at the cost of a small reduction in medical benefits, and thus improve the benefit/risk balance. At the provider level, this could include greater engagement and discussion with parents before testing. At the program implementation level, specific decisions about tradeoffs between sensitivity and specificity that could result in not identifying all infants with CF may be appropriate. At the policy decision level, deciding whether to implement CF NBS in a particular state could involve consideration of the availability of the financial resources, clinical services, and systems for assessing outcomes. Although CF NBS can be justified in settings in which the specific approach has a favorable benefit/risk balance, an inadequately designed screening program has the potential for being less favorable than the current approach of diagnosis on the basis of clinical criteria or family history.

Decreased lung function in female but not male subjects with established cystic fibrosis-related diabetes

OBJECTIVE

Although cystic fibrosis-related diabetes (CFRD) is associated with decreased lung function, sex is not known to influence CFRD. However, compared with male subjects with cystic fibrosis, female subjects with cystic fibrosis have increased morbidity. This study examines the association between female subjects with CFRD and poor lung function relative to male subjects using the percent predicted forced expiratory volume in 1 s (FEV(1)) as a surrogate measure of morbidity.

RESEARCH DESIGN AND METHODS

We compared 323 patients with established CFRD with 489 cystic fibrosis control subjects with normal glucose tolerance (NGT) listed in the U.K. Cystic Fibrosis Database. Patients stratified by sex and chronic Pseudomonas aeruginosa infection were compared using binary logistic regression, and patients with new CFRD diagnoses were compared prospectively for the year 2002.

RESULTS

CFRD in female subjects (but not male subjects) without chronic P. aeruginosa infection had a 20% lower percent predicted FEV(1) compared with control subjects with NGT (95% CI -11.7 to -27.7; P < 0.0001). Genotype, age, treatment center, age at diagnosis of cystic fibrosis, pregnancy, liver function, or dose of pancreatic enzyme replacement therapy did not confound this female disadvantage. Comparison of female subjects with newly diagnosed CFRD free of chronic P. aeruginosa infection with matched control subjects with NGT showed no FEV(1) disadvantage in the 1st year after CFRD diagnosis.

CONCLUSIONS

Only female subjects with CFRD have significantly decreased lung function compared with sex-matched NGT control subjects. The absence of poor lung function in the first 12 months after diagnosis of diabetes suggests that an opportunity may exist to intervene and possibly prevent a decline in lung function, which can be as much as 20% in female subjects with CFRD.

Multiple-breath washout as a marker of lung disease in preschool children with cystic fibrosis

Sensitive measures of lung function applicable to young subjects are needed to detect early cystic fibrosis (CF) lung disease. Forty children with CF aged 2 to 5 years and 37 age-matched healthy control subjects performed multiple-breath inert gas washout, plethysmography, and spirometry. Thirty children in each group successfully completed all measures, with success on first visit being between 68 and 86% for all three measures. Children with CF had significantly higher lung clearance index (mean [95% CI] difference for CF control 2.7 [1.9, 3.6], p < 0.001) and specific airway resistance (1.65 z-scores [0.96, 2.33], p < 0.001), and significantly lower forced expired volume in 0.5 seconds (-0.49 z-scores [-0.95, -0.03], p < 0.05). Abnormal lung function results were identified in 22 (73%) of 30 children with CF by multiple-breath washout, compared with 14 (47%) of 30 by plethysmography, and 4 (13%) of 30 by spirometry. Children with CF who were infected with Pseudomonas aeruginosa had significantly higher lung clearance index, but no significant difference in other lung function measures, when compared with noninfected children. Most preschool children can perform multiple-breath washout, plethysmography, and spirometry at first attempt. Multiple-breath washout detects abnormal lung function in children with CF more readily than plethysmography or spirometry.

Cystic fibrosis and lung transplantation — Determination of the survival benefit

INTRODUCTION

Cystic fibrosis is a well acknowledged indication for lung transplantation; however, the optimal timing for transplantation remains debatable. Liou et al. described a score for calculating 5-year probability of survival for patients with cystic fibrosis and concluded that only patients with a probability of survival < 30% gained a survival benefit from transplantation; those between 30% and 50% had equivocal survival effects from transplantation and those > 50% suffered negative effects. The aim of the present study was to determine the validity and applicability of this model.

METHODS

Data from patients with cystic fibrosis transplanted between January 1995 and July 2001 were retrospectively reviewed. Survival score according to Liou was calculated from data collected before transplantation. Patients were classified according to 5-year probability of survival (group 1: < 30%, group 2: 30%-50%, groups 3-5: > 50%). Actuarial survival rates were calculated separately for each group and compared with the predicted probability of survival.

RESULTS

During the observation period 27 patients were transplanted for cystic fibrosis. Three patients had to be excluded from further analysis because of incomplete pretransplant data. Fifteen patients were classified as group 1 and nine patients as group 2. No patients were eligible for groups 3 to 5. There were nine female patients and six males in group 1, mean age 22.1 +/- 4.9 years. Mean survival time was 918 +/- 787 days; 1-, 3- and 5-year survival rates were 66.6%. Three male patients and six females were classified as group 2, mean age 26.2 +/- 12.2 years. Mean survival time for this group was 701 +/- 617 days, and 1-, 3- and 5-year survival rates were 66.6%.

CONCLUSION

We found that only patients with a 5-year probability of survival < 50% had been transplanted. For patients in groups 1 and 2 we report identical 5-year survival rates of 66.6%. According to our experience, cystic fibrosis patients with a 5-year probability of survival < 30% and also those between 30% and 50% gain a clear survival benefit from bilateral lung transplantation.

Current status of paediatric heart, lung, and heart-lung transplantation

Since the first successful heart transplantation by Christian Barnard in 1967, there have been over 60 000 heart transplants performed worldwide. Around 350 paediatric heart transplants are now performed annually and approximately 10% of these are in the UK.

Recipient selection

Since international recommendations for lung transplant recipients were made in 1998, newer tools for predicting mortality in patients who have end-stage lung disease have been investigated. This article reviews studies for predicting mortality in obstructive, restrictive, pulmonary vascular, and suppurative/bronchiectatic lung disease. Newer considerations for alternative treatments, postoperative risks, and contraindications are also examined. The article aims to provide more accurate data for selecting patients who will benefit from lung transplantation.

Correlation of six different cystic fibrosis chest radiograph scoring systems with clinical parameters

In past decades, several chest radiograph scoring systems for cystic fibrosis were developed. This study was performed to compare interobserver variability of six different radiograph scores and to correlate them with clinical parameters. Thirty chest radiographs of 30 patients with cystic fibrosis were scored according to Shwachman-Kulczycki scoring, Chrispin-Norman scoring, adjusted Chrispin-Norman scoring, Brasfield scoring, Wisconsin scoring, and the Northern scoring system by two independent observers. Data on clinical parameters such as lung function, nutritional status, and infectious exacerbation rate, obtained simultaneously with the chest radiograph, were reviewed. Interobserver variability was low (Pearson's correlation coefficients, 0.76-0.84; all P < 0.01), and scores had good limits of agreement (Bland and Altman). Correlation of radiograph score with clinical parameters was good for most pulmonary function test data (correlation coefficients from 0.72-0.78 for percent of forced expired volume in 1 sec (FEV(1)%) predicted and from 0.69-0.74 for FVC% predicted) and for infectious exacerbation rate (correlation coefficients from 0.68-0.73). All six radiograph scoring systems, especially the Chrispin-Norman score, showed a low interobserver variability and correlated well with lung function tests, especially FEV(1)% predicted and infectious exacerbation rate, and moderately with maximum work capacity and thoracic mobility.

Developing cystic fibrosis lung transplant referral criteria using predictors of 2-year mortality

The first objective of our study was to develop a model identifying the best clinical predictors of 2-year mortality among patients with cystic fibrosis (CF), to assist in selection of appropriate candidates for lung transplantation. Using multivariate logistic regression, we found that age, height, FEV1, respiratory microbiology, number of hospitalizations for pulmonary exacerbations, and number of home intravenous antibiotic courses were all significant predictors of 2-year mortality among 14,572 patients in the Cystic Fibrosis Foundation National Patient Registry who were 6 years of age or older in 1996. The second objective was to compare the diagnostic accuracy of our model when used to guide referral for lung transplant with that of the widely used criterion of an FEV1 of less than 30% predicted. Surprisingly, this well-fitting model derived from the largest collection of data available on patients with CF provided no better diagnostic accuracy than the simpler FEV1 criterion. Both had high negative predictive values (98 and 97%, respectively) but only modest positive predictive values (33 and 28%, respectively). Transplant referral decisions based either on a multivariate logistic model or on the criterion of an FEV1 of less than 30% predicted are likely to result in high rates of premature referral. Better clinical predictors of short-term mortality among patients with CF are needed.

Liver disease in cystic fibrosis: A prospective study on incidence, risk factors, and outcome

Incidence of liver disease (LD) associated with cystic fibrosis (CF) and its clinical characterization still is unsettled. We have assessed prospectively the incidence and risk factors of this complication, and its impact on the clinical course of CF. Between 1980 and 1990, we enrolled 177 CF patients without LD in a systematic clinical, laboratory, ultrasonography screening program of at least a 10-year duration. During a 14-year median follow-up (2,432 patient-years), 48 patients developed LD, with cirrhosis already present in 5. Incidence rate (number of cases per 100 patient-years) was 1.8% (95% confidence interval: 1.3-2.4), with sharp decline after the age of 10 years and higher risk in patients with a history of meconium ileus (incidence rate ratio, 5.5; 2.7-11), male sex (2.5; 1.3-4.9), or severe mutations (2.4; 1.2-4.8) at multivariate analysis. Incidence of cirrhosis was 4.5% (2.3-7.8) during a median period of 5 years from diagnosis of liver disease. Among the 17 cirrhotic patients, 13 developed portal hypertension, 4 developed esophageal varices, 1 developed liver decompensation requiring liver transplantation. Development of LD did not condition different mortality (death rate ratio, 0.4; 0.1-1.5) or higher incidence of other clinically relevant outcomes. In conclusion, LD is a relatively frequent and early complication of CF, whose detection should be focused at the first life decade in patients with history of meconium ileus, male sex, or severe genotype. Although LD does not condition a different clinical course of CF, in some patients it may progress rapidly and require liver transplantation.

Selection of patients with cystic fibrosis for lung transplantation

Lung transplantation is the most aggressive therapy available for end-stage lung disease from cystic fibrosis (CF). A new predictive survival model of CF uses demographic, FEV1, nutritional, microbiologic, and acute exacerbation data to produce precise estimates of 5-year survival. The model improves the ability to select patients most likely to have survival benefit from transplantation. We discuss potential application of the survival model to four distinct groups of patients with CF: (1) candidates for cadaveric transplantation, (2) potential living donor recipients, (3) patients infected with multiply-resistant organisms such as Burkholderia cepacia, and (4) patients critically ill and dependent on mechanical ventilation. Measuring the impact of transplantation on quality of life remains a difficult task, and further studies are needed to determine whether lung-transplantation-derived survival benefit implies quality-of-life benefit. However, judicious use of the survival model to select patients for transplantation is likely to improve survival outcomes.

An elevated breathing reserve index at the lactate threshold is a predictor of mortality in patients with cystic fibrosis awaiting lung transplantation

The proportion of cystic fibrosis (CF) patients dying while on the lung transplant wait list remains high; identification of such patients remains difficult. The breathing reserve index (BRI = minute ventilation/maximal voluntary ventilation) at the lactate threshold (LT) is a predictor of a pulmonary mechanical limit to incremental exercise. We hypothesized that an elevated BRI at the LT in patients with CF awaiting lung transplantation would be a predictor of wait list mortality. Forty-five consecutive patients with CF completed cardiopulmonary exercise testing as part of their pretransplant assessment. We evaluated BRI at LT, baseline demographic characteristics, pulmonary function, and other exercise parameters via Cox proportional hazards modeling. Fifteen patients died while awaiting transplant. Twenty one were transplanted, and nine still awaited transplantation. Relative risks from the multivariate model included (95% confidence interval in parentheses) BRI at LT, 17.52 (2.45-123.97); resting Pa(CO(2)), 1.29 (1.10-1.49); resting Pa(O(2)), 0.97 (0.90-1.05); and forced expiratory volume at one second as a percent of predicted, 1.19 (1.05-1.34). BRI at LT not only provided the highest point estimate of risk for wait list mortality but also identified a physiologically significant threshold value (0.70 or more) for those at risk. This measurement may allow improved timing of listing for transplantation, including consideration for living donor transplantation.

Case-mix adjustment for evaluation of mortality in cystic fibrosis

Comparison of patient mortality rates in cystic fibrosis (CF) obtained from different institutions requires the use of case-mix adjustment methods to account for baseline differences in patient and disease characteristics. There is no current professional consensus on the use of case-mix adjustment methods for use in comparing mortality rates in CF. Characteristics used for this case-mix adjustment should include those that are different across institutions and are associated with patient survival. They should not include characteristics of disease severity that may be a consequence of effectiveness of treatment. The goal of these analyses was to identify a set of these characteristics of patients or disease that would be useful for case-mix adjustment of CF mortality rates. Data from the Cystic Fibrosis Foundation Patient Registry and from the United States Census of the Population (1990) were used in these analyses. Kaplan-Meier techniques, the log-rank test, and Cox proportional hazards regression were used to estimate survivorship, calculate hazard ratios (HR), 95% confidence intervals (CI(95%)), and to conduct tests of statistical significance. The data set included all 30,469 CF patients seen at CF Care Centers from 1982-1998. There were 5,906 deaths during 508,721 person-years of follow-up. In multivariate analyses, female gender (HR 1.30, CI(95%) (1.16, 1,47), P < 0.001), nonwhite race (HR 1.48, CI(95%) (1.07, 2.04), P = 0.018), Hispanic ethnicity (HR 1.85, CI(95%) (1.42, 2.43), P < 0.001), and symptomatic presentation (respiratory, gastrointestinal, respiratory and gastrointestinal, meconium ileus, and other symptomatic presentations; HRs 1.38-1.83; P values, 0.028 to < 0.001) were associated with higher risk of death. The homozygous Delta F508 genotype (HR 1.36, CI(95%) (1.19, 1.55), P < 0.001) and neither mutation being Delta F508 (HR 1.40, CI(95%) (1.15, 1.71), P = 0.001) were also associated with higher risk of death. Patients diagnosed after 36 months of age had almost 50% reduction in risk of death compared to those diagnosed before 6 months of age (HR 0.52 CI(95%) (0.44, 0.61), P < 0.001). When patients living in zip codes with a median household income > $50,000/year (corrected for the 1999 consumer price index) were compared with those living in areas with a median household income < $20,000/year, it was apparent that those in the wealthier areas had a 40% reduced risk of death (HR 0.60, CI(95%) (0.44, 0.82), P = 0.001). All of these characteristics were independently significant predictors of death, and all of these characteristics differed significantly across the CF Care Centers. This case-mix adjustment model uses patient and disease characteristics available at the time of diagnosis of CF, and is not believed to be influenced by subsequent treatment to predict the risk of death. If these case-mix adjustment methods are adopted broadly, they will make it possible to study treatment effects and differences in mortality outcomes, while adjusting for baseline differences in patient and disease characteristics.

Survival effect of lung transplantation among patients with cystic fibrosis

CONTEXT

Patients with cystic fibrosis (CF) are the second largest group of lung transplant recipients in the United States. The survival effect of transplantation on a general CF population has not previously been measured.

OBJECTIVE

To determine the impact of bilateral lung transplantation on survival in patients with CF.

DESIGN, SETTING, AND PATIENTS

Retrospective observational cohort study of 11 630 CF patients who did not undergo lung transplantation (controls) and 468 transplant recipients with CF from 115 CF centers in the United States, 1992-1998. Patients were stratified into 5 groups based on a 5-year survival prediction model (survival group 1: <30%; survival group 2: 30 to <50%; survival groups 3-5: 50 to <100%.)

MAIN OUTCOME MEASURE

Five-year survival from date of transplantation in 1992-1997 in the transplant group and from January 1, 1993, in the control group.

RESULTS

Lung transplantation increased 5-year survival of CF patients in survival group 1. Survival group 2 had equivocal survival effects, and groups 3-5 had negative survival effects from transplantation. From 1994-1997, there was a mean annual prevalence of 238 patients in survival group 1 and mean annual incidence of 154 patients entering the group, approximately 1.5 times the number of lung transplantations performed each year in CF patients (mean, 104). Use of the criterion of forced expiratory volume in 1 second of less than 30% resulted in an equivocal survival benefit and identified 1458 potential candidates for transplantation in 1993.

CONCLUSIONS

Cystic fibrosis patients in group 1 have improved 5-year survival after lung transplantation. The majority of patients with CF have equivocal or negative survival effects from the procedure. Selection of patients with CF for transplantation based on group 1 survival predictions maximizes survival benefits to individuals and may reduce the demand for scarce donor organs.

Liver transplantation in cystic fibrosis

Liver disease is the second most common cause of death in patients with cystic fibrosis (CF). Improvement in surgical techniques, medical management, and imaging modalities has broadened the range of options for treatment of these patients. Medical management with ursodeoxycholic acid and nutritional support may help decelerate the progression of liver disease. A timely evaluation of CF patients with liver involvement for transplantation is important. Such evaluation should not be delayed until signs of hepatic decompensation occur. Combined lung-liver transplant can be considered for patients with advanced pulmonary disease. Pretransplant management of portal hypertension with a portosystemic shunt procedure is an option for patients with well-preserved synthetic liver function. Improvement in lung function after liver transplantation and no significant risk of pulmonary infection with immunosuppressive therapy have been reported. Review of individual center experiences have shown satisfactory survival and improved quality of life for CF patients undergoing liver transplant.

Influence of neonatal screening and centralized treatment on long-term clinical outcome and survival of CF patients

After an experimental neonatal screening program for cystic fibrosis (CF) from 1973-1979, a follow-up study took place from 1980-1997. Patients were treated at specialized centres (C) or at local hospitals (non-C). Aims of the study were: 1) to determine whether the previously reported benefits from screening persisted with time and after adjustment for confounding variables; and 2) to investigate whether centre treatment was associated with improved prognosis of CF patients. Prognosis of patients detected by screening (S; n=24) was compared with patients detected clinically, born during (non-S; n=29) and after the screening programme (post-S; n=39). In addition, prognosis was compared between 45 C and 47 non-C patients. Multivariable regression analysis was used to compare survival and mixed-effects model regression analysis was used to compare clinical outcome between patients. The analyses included the variables screening, centre treatment, sex, meconium ileus and genotype. S patients had a significantly smaller decline in forced expiratory volume in one second (FEVI) (difference +2.74% predicted) and significantly lower immunoglobulin-G (IgG) levels (difference -473.69 mg x dL(-1)) than non-S patients until 12 yrs of age. At 12 yrs of age, vital capacity was significantly higher in S patients than in non-S patients (difference +362.79 mL). Survival seemed to be best for S patients compared to both non-S and post-S patients. Post-S patients were significantly heavier (difference in SD weight +0.77), had a significantly smaller decline in FEV1 (difference +2.80% pred) and lower IgG levels (difference -453.04 mg x dL(-1)) than non-S patients until 12 yrs of age. C patients had a significantly improved survival (relative risk (RR) 0.18, 95% confidence interval 0.05-0.57) than non-C patients. Early diagnosis through neonatal screening leads to better preservation of lung function in the long term in cystic fibrosis patients. Management of cystic fibrosis patients in specialized centres improves survival.

Sex differences in weight perception and nutritional behaviour in adults with cystic fibrosis

INTRODUCTION

Good nutritional status in cystic fibrosis (CF) is associated with improved clinical status and survival. In some conditions where dietary and pharmacological treatment are important (e.g. diabetes), a combination of eating disorders and failure of treatment compliance has been reported. Cases of eating disorders have been reported in CF. Societal pressures on young women to remain slim may compromise optimum clinical management as women are content to remain underweight.

OBJECTIVE

To determine whether women have different perception of their weight than men with CF and whether this manifests in different nutritional behaviour.

METHODS

Confidential postal questionnaire to 1870 adults with CF in 1994 known to the Association of Cystic Fibrosis Adults (UK). Participants were asked their own weight and height, and their perception of their weight. Very underweight was defined as < 85% ideal body weight, underweight as 85-94%, normal weight as 95-104%, overweight as 105-114% and very overweight as 115% and over.

RESULTS

A significantly higher proportion of women than men who are very underweight (29% vs. 11%) or underweight (41% vs. 15%) saw themselves as being of normal weight or overweight. Conversely, a significantly higher proportion of men than women who were normal weight (42% vs. 19%) saw themselves as underweight. All P-values < 0.01. A significantly higher proportion of people who perceived themselves to be underweight were taking oral or enteral food supplements compared with those who did not (77% vs. 30%, P < 0.05). Multiple logistic regression showed that perception of self as underweight was the strongest predictor of taking oral or enteral food supplements (adjusted odds ratio 2.42), even after adjustment for age, sex, overall severity score, body mass index, and seeing a dietitian in the last year.

CONCLUSION

Young women with CF tend to overestimate their weight, and young men with CF underestimate their weight when compared with their actual body weight. Perception of self as underweight is reflected in nutritional behaviour, being a significantpredictor of taking oral and enteral food supplements. People working with young patients with CF should be aware of these sex differences in weight perception, and work with young women and young men with CF to achieve a realistic perception of body weight and realistic nutritional goals. There is a need for further research into body image, weight perception, eating behaviour and adherence to pancreatic enzyme supplementation and oral and enteral food supplementation in young patients with CF.

Cystic fibrosis. End-stage care in Canada

OBJECTIVES

To determine the circumstances in which individuals with cystic fibrosis (CF) die, the role of different caregivers, and the extent of palliative care for CF patients.

DESIGN

Mailed survey of CF physicians.

SETTING

CF centers in Canada.

PATIENTS

All CF deaths in 1996 known to centers in Canada.

RESULTS

The mean age (+/- SD) at death of the 45 individuals included in the study was 25.8 +/- 13.5 years. The major cause of death was respiratory (34 patients; 75.5%). Nutritional concerns were common. Lung transplantation was considered in 42 patients (93.2%), with 7 patients (17.1%) being entered on a list, but it was carried out in only 2 patients (4.4%). Autopsies were performed on only 10 patients (22.2%). Most patients died in hospital (37 patients; 82.2%), and 7 patients (15.6%) died in ICUs while receiving intermittent positive-pressure ventilation. Palliative care was never discussed in 10 patients (25%). In a further 16 patients (40%), it was not discussed until the last month before death.

CONCLUSIONS

Respiratory disease remains the most common cause of death in CF patients. Lung transplantation is frequently considered, but most patients die without having had a transplant. Discussions on end-of-life care could be considered sooner.

Lung transplantation and end of life issues in cystic fibrosis

Lung transplantation has been available as a therapeutic option for patients with end-stage cystic fibrosis lung disease for over 15 years, but the outcome following transplantation remains poor, and the supply of organs limited. For this reason some children opt to continue with medical treatment followed by terminal care rather than undergo transplantation. This article summarizes the current status of lung transplantation, including current referral guidelines and contraindications and also addresses current practice in terminal care.

Pulmonary hemodynamics contribute to indicate priority for lung transplantation in patients with cystic fibrosis

OBJECTIVE

Lung transplantation is a viable option for patients with cystic fibrosis. The current strategy of selection, based on spirometry and deterioration of quality of life, results in a high mortality on the waiting list. We reviewed the case histories of patients with cystic fibrosis accepted for lung transplantation to ascertain whether pulmonary hemodynamics could contribute to predict life expectancy.

METHODS

Forty-five patients with cystic fibrosis were accepted: 11 died on the waiting list (group I), 24 underwent transplantation (group II), and 10 are still waiting (group III). During evaluation we recorded spirometry, oxygen requirement, ratio of arterial oxygen tension to inspired oxygen fraction (PaO (2)/FIO (2)), arterial carbon dioxide tension (PaCO (2)), 6-minute walk test results, right ventricular ejection fraction, echocardiography, and pulmonary hemodynamics. We compared data from group I, II, and III patients. A comparison was also made within group II between the data collected at the time of evaluation and at the time of transplantation to quantify the deterioration during the waiting time.

RESULTS

The waiting time, spirometry, 6-minute walk test results, and right ventricular ejection fraction did not differ among the three groups. A statistically significant difference was found for PaO (2)/FIO (2), PaCO (2), mean pulmonary artery pressure, cardiac index, pulmonary arterial wedge pressure, and intrapulmonary shunt between groups I and II. Groups I and III showed statistically significant differences for mean pulmonary artery pressure, PaO (2)/FIO (2), and systemic vascular resistance indexed. No differences were observed between groups II and III. The comparison within group II showed a significant deterioration of pulmonary hemodynamics during the waiting time.

CONCLUSIONS

Pulmonary hemodynamics are worst in patients dying on the waiting list and deteriorate significantly during the waiting time. They may thus contribute to establish priority for lung transplantation in patients with cystic fibrosis.