Cardio-pulmonary interaction in premature newborn with nasal continuous positive airways pressure (n-CPAP) respiratory assistance evaluated with echocardiography

Introduction: Nasal continuous positive airways pressure (n-CPAP) is an effective treatment in premature infants with respiratory distress. The cardio-pulmonary interactions secondary to n-CPAP are well studied in adults, but less well described in premature infants. We postulated that there could be important interactions with regard to the patent ductus arteriosus (PDA). Methods: Prospective study, approved by the local ethic committee. Premature infants less than 32 weeks gestation, _7 days-old, needing n-CPAP for respiratory distress, but without the need of additional oxygen were included in the study. Every patient had a first echocardiography with n-CPAP and then n-CPAP was retrieved. 3 hours later the echocardiography was repeated by the same investigator and then the patient replaced on n-CPAP. Results: 14 premature newborn were included, mean gestational age of 28 _ 2 weeks, mean weight 1.1 _ 0.3 Kg and height 39 _ 3 cm. Echocardiographic measurements are depicted in Table 1. Significant finding were observed between measurement on n- CPAP or without n-CPAP: on end diastolic left ventricular diameter (12.8 _ 1.6 mm vs. 13.5 _ 2 mm), on end systolic left ventricular diameter (8.4 _ 1.3 mm vs. 9.1 _ 1.5 mm), left atrium diameter (8.9 _ 2.2 mm vs. 10.4 _ 2.5 mm), maximal velocity on tricuspid valve (46 _ 10 cm/s vs. 51 _ 9 cm/s), calculated Qp (3.7 _ 0.8 L/min/m2 vs. 4.3 _ 0.8 L/min/m2). Only three patients have demonstrated a PDA during the study. Conclusion: Positive end expiratory pressure (Peep) has hemodynamic effects which are: reduction of systemic and pulmonary venous return as shown by the changes on tricuspid valve inflow,on the calculated Qp and finally on the diameter of the left atrium and left ventricle.We found in premature infants the same hemodynamic effects than those described in adults but with lower Peep values. This could be due to the particular elasticity and weakness of the thoracic wall of premature infants. Interestingly the flow through a PDA seems also to be diminished with Peep, but the number of patients is insufficient to conclude. Further investigation will be needed to better understand these interactions. Table 1. Echocardiographic measurement (mean (SD)). With n-CPAP Without n-CPAP p value RV ED diameter (mm) 6.3 (1.7) 6.04 (1.1) NS LV ED diameter (mm) 12.8 (1.6) 13.5 (2.0) _0.05 LV ES diameter (mm) 8.4 (1.3) 9.1 (1.5) _0.05 SF (%) 34 (5) 33 (6) NS Ao valve diameter (mm) 7.4 (1.3) 7.4 (1.2) NS LA diameter (mm) 8.9 (2.2) 10.4 (2.5) _0.05 Vmax Ao (cm/s) 70 (16) 71 (18) NS Vmax PV (cm/s) 69 (15) 72 (16) NS Vmax TV (cm/s) 46 (10) 51 (9) _0.05 Vmax MV (cm/s) 53 (17) 54 (18) NS Qp (L/min/m2) 3.7 (0.8) 4.3 (0.8) _0.05 Qs (L/min/m2) 4.0 (0.8) 4.0 (0.7) NS Qp/Qs 0.92 (0.14) 1.09 (0.23) _0.05 RV: right ventricle, LV: left ventricle, ED: end diastolic, ES: end systolic, SF: shortening fraction,Ao: aortic valve, LA: left atrium,Vmax: maximum Doppler Velocity, Qp: pulmonary output, Qs: systemic output, NS: non significant.

Improved accuracy of co-morbidity coding over time after the introduction of ICD-10 administrative data.

BACKGROUND: Co-morbidity information derived from administrative data needs to be validated to allow its regular use. We assessed evolution in the accuracy of coding for Charlson and Elixhauser co-morbidities at three time points over a 5-year period, following the introduction of the International Classification of Diseases, 10th Revision (ICD-10), coding of hospital discharges.METHODS: Cross-sectional time trend evaluation study of coding accuracy using hospital chart data of 3'499 randomly selected patients who were discharged in 1999, 2001 and 2003, from two teaching and one non-teaching hospital in Switzerland. We measured sensitivity, positive predictive and Kappa values for agreement between administrative data coded with ICD-10 and chart data as the 'reference standard' for recording 36 co-morbidities.RESULTS: For the 17 the Charlson co-morbidities, the sensitivity - median (min-max) - was 36.5% (17.4-64.1) in 1999, 42.5% (22.2-64.6) in 2001 and 42.8% (8.4-75.6) in 2003. For the 29 Elixhauser co-morbidities, the sensitivity was 34.2% (1.9-64.1) in 1999, 38.6% (10.5-66.5) in 2001 and 41.6% (5.1-76.5) in 2003. Between 1999 and 2003, sensitivity estimates increased for 30 co-morbidities and decreased for 6 co-morbidities. The increase in sensitivities was statistically significant for six conditions and the decrease significant for one. Kappa values were increased for 29 co-morbidities and decreased for seven.CONCLUSIONS: Accuracy of administrative data in recording clinical conditions improved slightly between 1999 and 2003. These findings are of relevance to all jurisdictions introducing new coding systems, because they demonstrate a phenomenon of improved administrative data accuracy that may relate to a coding 'learning curve' with the new coding system.

Delay for admission of unstable hospitalized patients to intensive care unit: a need for a medical emergency team?

INTRODUCTION. Patients admitted in Intensive Care Unit (ICU) from general wards are more severe and have a higher mortality than those admitted from emergency department as reported [1]. The majority of them develop signs of instability (e.g. tachypnea, tachycardia, hypotension, decreased oxygen saturation and change in conscious state) several hours before ICU admission. Considering this fact and that in-hospital cardiac arrests and unexpected deaths are usually preceded by warning signs, immediate on site intervention by specialists may be effective. This gave an impulse to medical emergency team (MET) implementation, which has been shown to decrease cardiac arrest, morbidity and mortality in several hospitals. OBJECTIVES AND METHODS. In order to verify if the same was true in our hospital and to determine if there was a need for MET, we prospectively collected all non elective ICU admissions of already hospitalized patients (general wards) and of patients remaining more than 3 h in emergency department (considered hospitalized). Instability criteria leading to MET call correspond to those described in the literature. The delay between the development of one criterion and ICU admission was registered. RESULTS. During an observation period of 12 months, 321 patients with our MET criteria were admitted to ICU. 88 patients came from the emergency department, 115 from the surgical and 113 from the medical ward. 65% were male. The median age was 65 years (range 17-89). The delay fromMETcriteria development to ICU admission was higher than 8 h in 155 patients, with a median delay of 32 h and a range of 8.4 h to 10 days. For the remaining 166 patients, an early MET criterion was present up to 8 h (median delay 3 h) before ICU admission. These results are quite concordant with the data reported in the literature (ref 1-8). 122 patients presented signs of sepsis or septic shock, 70 patients a respiratory failure, 58 patients a cardiac emergency. Cardiac arrest represent 5% of our collective of patients. CONCLUSIONS.Similar to others observations, the majority of hospitalized patients admitted on emergency basis in our ICU have warning signs lasting for several hours. More than half of them were unstable for more than 8 h. This shows there is plenty of time for early acute management by dedicated and specialized team such as MET. However, further studies are required to determine if MET implementation can reduce in-hospital cardiac arrests and influence the morbidity, the length of stay and the mortality.

Kartagener syndrome: an uncommon cause of neonatal respiratory distress?

We report a newborn with respiratory distress and situs inversus totalis. The diagnosis of primary ciliary dyskinesia was confirmed by both ultrastructural and functional investigations. The immotile cilia syndrome was suspected because of respiratory distress, situs inversus, abnormal nasal discharge and hyperinflated chest X-ray. We suggest that ultrastructural and functional investigations of the respiratory mucosa should be done in any newborn with respiratory distress without explanation for the respiratory problems. Establishment of the correct diagnosis at an early stage may allow to improve the prognosis provided prophylactic physiotherapy, vaccinations, and aggressive antibiotic treatment of intercurrent respiratory infections are instituted. CONCLUSION Despite its rarity, primary ciliary dyskinesia should be considered in unexplained cases of neonatal distress.

Neonatal treatment with recombinant ectodysplasin prevents respiratory disease in dogs with X-linked ectodermal dysplasia.

Patients with defective ectodysplasin A (EDA) have X-linked hypohidrotic ectodermal dysplasia (XLHED; OMIM#305100), a condition comprising hypotrichosis, inability to sweat, abnormal teeth, and frequent pulmonary infections. The XLHED dogs show the same clinical signs as humans with the disorder, including frequent respiratory infections that can be fatal. The respiratory disease in humans and dogs is thought to be due to the absence of tracheal and bronchial glands which are a vital part of the mucociliary clearance mechanism. In our XLHED model, the genetically missing EDA was replaced by postnatal intravenous administration of recombinant EDA resulting in long-term, durable corrective effect on adult, permanent dentition. After treatment with EDA, significant correction of the missing tracheal and bronchial glands was achieved in those dogs that received higher doses of EDA. Moreover, successful treatment resulted in the presence of esophageal glands, improved mucociliary clearance, and the absence of respiratory infection. These results demonstrate that a short-term treatment at a neonatal age with a recombinant protein can reverse a developmental disease and result in vastly improved quality of life.

Congenital diaphragmatic hernia : a European population-based study of epidemiology, prenatal diagnosis and mortality

Aim: To study the epidemiology and the impact of prenatal diagnosis on mortality and morbidity in infants with isolated congenital diaphragmatic hernia (CDH). Methods: Cases were identified in eight population-based registries of congenital malformations (Eurocat) in Europe. Results: A total of 183 live births were included in the study. Sixty per cent died and 67% of all deaths were during the first day of life. CDH was diagnosed prenatally in 39% of cases. Both mortality and morbidity were significantly higher for infants diagnosed prenatally compared to those diagnosed postnatally. The Apgar score was a very sensitive indicator for survival. Gestational age at birth was significantly lower for infants diagnosed prenatally compared to those diagnosed postnatally (37.6 weeks vs. 38.8 weeks, p < 0.01). At the end of follow-up, half of the survivors were leading a normal life. The most frequently reported health problems were respiratory and gastrointestinal symptoms. Conclusions: In this population-based study, mortality for infants with CDH was high (60%) and early prenatal diagnosis was a risk factor for survival. Intervention at the time of birth seems too late for the majority of newborn infants with CDH.

Multifocalité du carcinome épidermoïde sur les voies digestive supérieure et respiratoire distale : technicité du diagnostic endoscopique [Multiple squamous cell carcinoma of the upper digestive and lower respiratory tracts : methodology of endoscopic screening]

L'étude porte sur 951 porteurs d'un cancer primaire bucco-pharyngo-laryngé, et révèle un taux de multifocalité du carcinome épidermoïde sur les voies digestive supérieure (bouche-pharynx-oesophage) et aérienne distale (larynx-trachée-bronches) s'élevant à 14,5 %. Les secondes localisations peuvent être simultanées (6,4 %) ou successives (8,1 %) à la découverte du premier cancer: dès la deuxième année du follow-up leur incidence dépasse celle des récidives. Elles se localisent tant au niveau ORL (8,5 %) qu'oesophagien (3 %) ou bronchique (3 %). Le cancer du voile présente un taux de multifocalité particulièrement élevé (51 %). Les auteurs décrivent un type d'endoscopie de dépistage (bucco-pharyngo-oesophago-laryngo-trachéobronchoscopie) dont la fiabilité repose sur une technicité spécifique d'une part, et sur la connaissance des caractéristiques propres aux secondes localisations d'autre part. Ce dépistage systématique permet de détecter les tumeurs secondaires à un stade le plus souvent précoce et encore asymptomatique.

Respiratory variability in mechanically ventilated patients. Critical Care 2011

Introduction: Increased respiratory pattern variability is associated with improved oxygenation. Pressure support (PS) is a widely used partial-assist mechanical ventilation (MV) mode, in which each breathing cycle is initiated by flow or pressure variation at the airway due to patient inspiratory effort. Neurally adjusted ventilatory assist (NAVA) is relatively new and uses the electrical activity of the diaphragm (Eadi) to deliver ventilatory support proportional to the patient's inspiratory demand. We hypothesize that respiratory variability should be greater with NAVA compared with PS.Methods: Twenty-two patients underwent 20 minutes of PS followed by 20 minutes of NAVA. Flow and Eadi curves were used to obtain tidal volume (Vt) and ∫Eadi for 300 to 400 breaths in each patient. Patient-specific cumulative distribution functions (CDF) show the percentage Vt and ∫Eadi within a clinically defined (±10%) variability band for each patient. Values are normalized to patient-specific medians for direct comparison. Variability in Vt (outcome) is thus expressed in terms of variability in ∫Eadi (demand) on the same plot.Results: Variability in Vt relative to variability in ∫Eadi is significantly greater for NAVA than PS (P = 0.00012). Hence, greater variability in outcome Vt is obtained for a given demand in ∫Eadi, under NAVA, as illustrated in Figure 1 for a typical patient. A Fisher 2 × 2 contingency analysis showed that 45% of patients under NAVA had a Vt variability in equal proportion to ∫Eadi variability, versus 0% for PS (P < 0.05).Conclusions: NAVA yields greater variability in tidal volume, relative to ∫Eadi demand, and a better match between Vt and ∫Eadi. These results indicate that NAVA could achieve improved oxygenation compared with PS when sufficient underlying variability in ∫Eadi is present, due to its ability to achieve higher tidal volume variability from a given variability in ∫Eadi.

Techniques d'évaluation de la force des muscles respiratoires. [Techniques for assessing respiratory muscle strength.]

La faiblesse des muscles respiratoires peut entraîner une dyspnée, un encombrement bronchique et une insuffisance respiratoire potentiellement fatale. L'évaluation de la force musculaire respiratoire s'impose donc dans les affections neuro-musculaires, mais également dans les situations de dyspnée inexpliquée par une première évaluation cardiaque et pulmonaire. À la spirométrie, une faiblesse musculaire est suspectée sur la base de la boucle débit-volume montrant un débit de pointe émoussé et une fin prématurée de l'expiration. Une diminution importante de la capacité vitale en position couchée suggère une paralysie diaphragmatique. La force inspiratoire est mesurée par la pression inspiratoire maximale (PImax) contre une quasi-occlusion des voies aériennes. Ce test relativement difficile est d'interprétation délicate en cas de collaboration insuffisante. La mesure de la pression nasale sniff (SNIP) est une alternative utile, car elle élimine le problème des fuites autour de l'embout buccal et la réalisation du reniflement est facile. De même, la pression trans-diaphragmatique sniff mesure la force du diaphragme au moyen de sondes oesophagienne et gastrique. En cas de collaboration insuffisante, on peut recourir à la stimulation magnétique des nerfs phréniques qui induit une contraction non-volontaire du diaphragme. La force expiratoire est mesurée par la pression expiratoire maximale (PEmax) contre une quasi-occlusion. La force disponible pour tousser est mesurée par la pression gastrique à la toux, ou plus simplement par le débit de pointe à la toux. Chez les patients à risque, la mesure de la force des muscles respiratoires permet d'instaurer à temps une assistance ventilatoire ou à la toux.

Rhinovirus Genome Variation during Chronic Upper and Lower Respiratory Tract Infections.

Routine screening of lung transplant recipients and hospital patients for respiratory virus infections allowed to identify human rhinovirus (HRV) in the upper and lower respiratory tracts, including immunocompromised hosts chronically infected with the same strain over weeks or months. Phylogenetic analysis of 144 HRV-positive samples showed no apparent correlation between a given viral genotype or species and their ability to invade the lower respiratory tract or lead to protracted infection. By contrast, protracted infections were found almost exclusively in immunocompromised patients, thus suggesting that host factors rather than the virus genotype modulate disease outcome, in particular the immune response. Complete genome sequencing of five chronic cases to study rhinovirus genome adaptation showed that the calculated mutation frequency was in the range observed during acute human infections. Analysis of mutation hot spot regions between specimens collected at different times or in different body sites revealed that non-synonymous changes were mostly concentrated in the viral capsid genes VP1, VP2 and VP3, independent of the HRV type. In an immunosuppressed lung transplant recipient infected with the same HRV strain for more than two years, both classical and ultra-deep sequencing of samples collected at different time points in the upper and lower respiratory tracts showed that these virus populations were phylogenetically indistinguishable over the course of infection, except for the last month. Specific signatures were found in the last two lower respiratory tract populations, including changes in the 5'UTR polypyrimidine tract and the VP2 immunogenic site 2. These results highlight for the first time the ability of a given rhinovirus to evolve in the course of a natural infection in immunocompromised patients and complement data obtained from previous experimental inoculation studies in immunocompetent volunteers.

Respiratory surveillance of patients with Duchenne and Becker muscular dystrophy.

Duchenne muscular dystrophy is is the most common form of the childhood muscular dystrophies. It follows a predictable clinical course marked by progressive skeletal muscle weakness, lost of ambulation before teen-age and death in early adulthood secondary to respiratory or cardiac failure. Becker muscular dystrophy is less common and has a milder clinical course but also results in respiratory and cardiac failure.Altough recent advances in respiratory care and new technologies have improved the outlook many patients already received only a traditional non-interventional approach. The aims of this work are: to analyse the pathophysiology and natural history of respiratory function in these diseases, to descript their clinical manifestations, to present the diagnostics tools and to provide recommendations for an adequated respiratory care in this particular population based on the updated literature referenced.

Development of a new chlamydiales-specific real-time PCR and its application to respiratory clinical samples.

Originally composed of the single family Chlamydiaceae, the Chlamydiales order has extended considerably over the last several decades. Chlamydia-related bacteria were added and classified into six different families and family-level lineages: the Criblamydiaceae, Parachlamydiaceae, Piscichlamydiaceae, Rhabdochlamydiaceae, Simkaniaceae, and Waddliaceae. While several members of the Chlamydiaceae family are known pathogens, recent studies showed diverse associations of Chlamydia-related bacteria with human and animal infections. Some of these latter bacteria might be of medical importance since, given their ability to replicate in free-living amoebae, they may also replicate efficiently in other phagocytic cells, including cells of the innate immune system. Thus, a new Chlamydiales-specific real-time PCR targeting the conserved 16S rRNA gene was developed. This new molecular tool can detect at least five DNA copies and show very high specificity without cross-amplification from other bacterial clade DNA. The new PCR was validated with 128 clinical samples positive or negative for Chlamydia trachomatis or C. pneumoniae. Of 65 positive samples, 61 (93.8%) were found to be positive with the new PCR. The four discordant samples, retested with the original test, were determined to be negative or below detection limits. Then, the new PCR was applied to 422 nasopharyngeal swabs taken from children with or without pneumonia; a total of 48 (11.4%) samples were determined to be positive, and 45 of these were successfully sequenced. The majority of the sequences corresponded to Chlamydia-related bacteria and especially to members of the Parachlamydiaceae family.

Smoking, prevalence of disease and health service utilization among the Swiss population.

The data of the 1981-83 Swiss National Health Survey "SOMIPOPS", based on a randomly selected sample of 4,235 individuals aged 20 or over representative of the whole Swiss population, were used to investigate the relation between smoking, prevalence of disease and frequency of health care utilization. The risks of several conditions, including hypertension, myocardial infarction and other heart diseases, asthma, tuberculosis and kidney disease were elevated among ex-smokers. The diseases showing elevated risks among current smokers and significantly positive dose-risk trends included acute bronchitis (relative risk, RR = 3.2 for heavy cigarette smokers vs never smokers), chronic bronchitis or lung emphysema (RR = 2.0), gastro-duodenal ulcer (RR = 1.8) and bone fractures (RR = 1.6). For respiratory conditions, the risk of pipe or cigar smokers was comparable to that of moderate cigarette smokers, whereas for ulcer (RR = 4.1) or fractures (RR = 2.0) the point estimates were even higher than for heavy cigarette smokers. Smokers tended to consult more frequently general practitioners, used more other outpatients services, and were more frequently admitted to hospital during the year preceding the interview. These effects were consistent across strata of age, socio-economic indicators, and persisted after allowance for major identified potential distorting factors. Thus, the results of this survey confirm that smoking is an important cause of morbidity and a major contributory factor to the use of health services.