Respiratory nitric oxide and pulmonary artery pressure in children of aymara and European ancestry at high altitude.

Invasive studies suggest that healthy children living at high altitude display pulmonary hypertension, but the data to support this assumption are sparse. Nitric oxide (NO) synthesized by the respiratory epithelium regulates pulmonary artery pressure, and its synthesis was reported to be increased in Aymara high-altitude dwellers. We hypothesized that pulmonary artery pressure will be lower in Aymara children than in children of European ancestry at high altitude, and that this will be related to increased respiratory NO. We therefore compared pulmonary artery pressure and exhaled NO (a marker of respiratory epithelial NO synthesis) between large groups of healthy children of Aymara (n = 200; mean +/- SD age, 9.5 +/- 3.6 years) and European ancestry (n = 77) living at high altitude (3,600 to 4,000 m). We also studied a group of European children (n = 29) living at low altitude. The systolic right ventricular to right atrial pressure gradient in the Aymara children was normal, even though significantly higher than the gradient measured in European children at low altitude (22.5 +/- 6.1 mm Hg vs 17.7 +/- 3.1 mm Hg, p < 0.001). In children of European ancestry studied at high altitude, the pressure gradient was 33% higher than in the Aymara children (30.0 +/- 5.3 mm Hg vs 22.5 +/- 6.1 mm Hg, p < 0.0001). In contrast to what was expected, exhaled NO tended to be lower in Aymara children than in European children living at the same altitude (12.4 +/- 8.8 parts per billion [ppb] vs 16.1 +/- 11.1 ppb, p = 0.06) and was not related to pulmonary artery pressure in either group. Aymara children are protected from hypoxic pulmonary hypertension at high altitude. This protection does not appear to be related to increased respiratory NO synthesis.

Respiratory responses associated with affective processing of film stimuli

We investigated respiratory responses during film clip viewing and their relation to the affective dimensions of valence and arousal. Seventy-six subjects participated in a study using a between groups design. To begin with, all participants viewed an emotionally neutral film clip. Then, they were presented with one out of four emotional film clips: a positive high-arousal, a positive low-arousal, a negative high-arousal and a negative low-arousal clip. Respiration, skin conductance level, heart rate, corrugator activity and affective judgments were measured. Expiratory time was shorter and inspiratory duty cycle, mean expiratory flow and minute ventilation were larger during the high-arousal clips compared to the low-arousal clips. The pleasantness of the stimuli had no influence on any respiratory measure. These findings confirm the importance of arousal in respiratory responding but also evidence differences in comparison to previous studies using visual and auditory stimuli. [Authors]

Diagnosis and management of chronic obstructive pulmonary disease: the swiss guidelines: official guidelines of the Swiss Respiratory Society.

The new Swiss Chronic Obstructive Pulmonary Disease (COPD) Guidelines are based on a previous version, which was published 10 years ago. The Swiss Respiratory Society felt the need to update the previous document due to new knowledge and novel therapeutic developments about this prevalent and important disease. The recommendations and statements are based on the available literature, on other national guidelines and, in particular, on the GOLD (Global Initiative for Chronic Obstructive Lung Disease) report. Our aim is to advise pulmonary physicians, general practitioners and other health care workers on the early detection and diagnosis, prevention, best symptomatic control, and avoidance of COPD as well as its complications and deterioration.

Prolonged remission of juvenile-onset respiratory papillomatosis: a post-expositional role of the tetravalent anti-HPV vaccine?

Juvenile-onset recurrent respiratory papillomatosis (JORRP) is an HPV-related neoplasm affecting primarily the larynx. JORRP often requires repeated surgical debridement, which yield variable but generally moderate remission periods. We report the case of a 6-year-old boy with severe course JORRP since the age of 2, requiring tracheostomy, that underwent prolonged remission and was decannulated some months after administration of the HPV vaccine. The post-exposure use for the anti-HPV vaccine in JORRP is a topic of capital interest but still poorly characterized. Some published cases suggest a potential post-exposure role of the vaccine in JORRP, but prospective multicentric trials are still needed.

Upper and lower respiratory tract viral infections and acute graft rejection in lung transplant recipients.

Background: Lung transplant recipients are frequently exposed to respiratory viruses and are particularly at risk for severe complications. The aim of this study was to assess the association among the presence of a respiratory virus detected by molecular assays in bronchoalveolar lavage (BAL) fluid, respiratory symptoms, and acute rejection in adult lung transplant recipients. Methods: Upper (nasopharyngeal swab) and lower (BAL) respiratory tract specimens from 77 lung transplant recipients enrolled in a cohort study and undergoing bronchoscopy with BAL and transbronchial biopsies were screened using 17 different polymerase chain reaction-based assays. Result: BAL fluid and biopsy specimens from 343 bronchoscopic procedures performed in 77 patients were analyzed. We also compared paired nasopharyngeal and BAL fluid specimens collected in a subgroup of 283 cases. The overall viral positivity rate was 29.3% in the upper respiratory tract specimens and 17.2% in the BAL samples (). We observed a significant association P < .001 between the presence of respiratory symptoms and positive viral detection in the lower respiratory tract (Pp. 012). Conversely, acute rejection was not associated with the presence of viral infection (odds ratio, 0.41; 95% confidence interval, 0.20-0.88). The recovery of lung function was significantly slower when acute rejection and viral infection were both present. Conclusions: A temporal relationship exists between acute respiratory symptoms and positive viral nucleic acid detection in BAL fluid from lung transplant recipients. We provide evidence suggesting that respiratory viruses are not associated with acute graft rejection during the acute phase of infection.

Feasibility of non-invasive pressure support ventilation in infants with respiratory failure after extubation: a pilot study.

OBJECTIVE: To evaluate the feasibility and effects of non-invasive pressure support ventilation (NIV) on the breathing pattern in infants developing respiratory failure after extubation. DESIGN: Prospective pilot clinical study; each patient served as their own control. SETTING: A nine-bed paediatric intensive care unit of a tertiary university hospital. PATIENTS: Six patients (median age 5 months, range 0.5-7 months; median weight 4.2 kg, range 3.8-5.1 kg) who developed respiratory failure after extubation. INTERVENTIONS: After a period of spontaneous breathing (SB), children who developed respiratory failure were treated with NIV. MEASUREMENTS AND RESULTS: Measurements included clinical dyspnoea score (DS), blood gases and oesophageal pressure recordings, which were analysed for respiratory rate (RR), oesophageal inspiratory pressure swing (dPes) and oesophageal pressure-time product (PTPes). All data were collected during both periods (SB and NIV). When comparing NIV with SB, DS was reduced by 44% (P < 0.001), RR by 32% (P < 0.001), dPes by 45% (P < 0.01) and PTPes by 57% (P < 0.001). A non-significant trend for decrease in PaCO(2) was observed. CONCLUSION: In these infants, non-invasive pressure support ventilation with turbine flow generator induced a reduction of breathing frequency, dPes and PTPes, indicating reduced load of the inspiratory muscles. NIV can be used with some benefits in infants with respiratory failure after extubation.

Influence of compliance to respiratory weaning consensus conference criteria on respiratory outcome within 48h after planned extubation

INTRODUCTION. A two-step assessment (readiness to wean (RW) followed by spontaneousbreathing trial (SBT)) of predefined criteria is recommended before planned extubation(PE)1.OBJECTIVES. We aimed to evaluate if compliance to all guideline criteria was associatedwith better respiratory outcome within 48 h after PE.METHODS. The data (extracted from our clinical information system) of 458 consecutivepatients who underwent PE after C48 h of invasive ventilation in our medico-surgical ICUwere analyzed. We evaluated compliance with guidelines [1] regarding respiratory rate, tidalvolume, PaO2, FiO2, PEEP, PaCO2, pH, heart rate, systolic arterial pressure and arrhythmiaduringRWand SBT assessment (RW and SBT within 2 h). A patient was classified as RW+ ifallRWcriteria were fulfilled andRW-if at least 1 criterion was violated. The same approachwas used to define SBT+ and SBT- patients. During the 48 h following PE, we assessed theoccurrence of post-PE respiratory failure (PRF) (defined as the presence of at least 1 consensuscriterion of respiratory failure [1]), reintubation (after NIV failure or because of immediateintubation criteria) and cumulative duration of post-PE ventilation (PPEV = Post-PE invasive+ non-invasive ventilation). ICU mortality was recorded. Comparisons for variousoutcomes were performed by Chi-square and t tests.RESULTS. All consensus criteria were fulfilled in 77.3% of the patients during RW and in68.1% of the patients during SBT.[Compliance to weaning criteria and outcome]N = 458 PRF (%) Reintubation (%) PPEV (min) ICU mortality (%)All patients 53.5 10.0 542 ± 664 6.1RW+ 50.0 9.3 490 ± 626 5.4RW- 65.4* 12.5 718 ± 757** 8.7SBT+ 52.6 8.0 498 ± 594 6.7SBT- 55.5 14.4*** 637 ± 788**** 4.8Occurrence of PRF only was not associated with increased ICU mortality: 4.2 versus 7.8%,p = 0.11. By contrast, ICU mortality was significantly increased in patients requiring reintubation:21.7 versus 4.4%. p\0.001; * p = 0.006 RW+ versus RW-; ** p = 0.003RW+ versus RW-; *** p = 0.035 SBT+ versus SBT-; **** p = 0.030 SBT+ versusSBTCONCLUSIONS.In our ICU, compliance to all criteria of the two-step published approach ofrespiratory weaning was not optimal but reintubation rate was comparable to published data.Compliance with consensus conference guidelines was associated with lower reintubation rateand shorter PPEV but not with ICU mortality. As mortality was increased by reintubation,more sensitive and specific criteria to predict the risk of reintubation are probably needed.REFERENCE. Boles JM, et al. Eur Respir J 2007;29:1033-56.

Urinary hexane diamine to assess respiratory exposure to hexamethylene diisocyanate aerosol: a human inhalation study

The use of urinary hexane diamine (HDA) as a biomarker to assess human respiratory exposure to hexamethylene diisocyanate (HDI) aerosol was evaluated. Twenty-three auto body shop workers were exposed to HDI biuret aerosol for two hours using a closed exposure apparatus. HDI exposures were quantified using both a direct-reading instrument and a treated-filter method. Urine samples collected at baseline, immediately post exposure, and every four to five hours for up to 20 hours were analyzed for HDA using gas chromatography and mass spectrometry. Mean urinary HDA (microg/g creatinine) sharply increased from the baseline value of 0.7 to 18.1 immediately post exposure and decreased rapidly to 4.7, 1.9 and 1.1, respectively, at 4, 9, and 18 hours post exposure. Considerable individual variability was found. Urinary HDA can assess acute respiratory exposure to HDI aerosol, but may have limited use as a biomarker of exposure in the workplace. [Authors]

Automatic selection of tidal volume, respiratory frequency and minute ventilation in intubated ICU patients as start up procedure for closed-loop controlled ventilation.

OBJECTIVE: Before a patient can be connected to a mechanical ventilator, the controls of the apparatus need to be set up appropriately. Today, this is done by the intensive care professional. With the advent of closed loop controlled mechanical ventilation, methods will be needed to select appropriate start up settings automatically. The objective of our study was to test such a computerized method which could eventually be used as a start-up procedure (first 5-10 minutes of ventilation) for closed-loop controlled ventilation. DESIGN: Prospective Study. SETTINGS: ICU's in two adult and one children's hospital. PATIENTS: 25 critically ill adult patients (age > or = 15 y) and 17 critically ill children selected at random were studied. INTERVENTIONS: To stimulate 'initial connection', the patients were disconnected from their ventilator and transiently connected to a modified Hamilton AMADEUS ventilator for maximally one minute. During that time they were ventilated with a fixed and standardized breath pattern (Test Breaths) based on pressure controlled synchronized intermittent mandatory ventilation (PCSIMV). MEASUREMENTS AND MAIN RESULTS: Measurements of airway flow, airway pressure and instantaneous CO2 concentration using a mainstream CO2 analyzer were made at the mouth during application of the Test-Breaths. Test-Breaths were analyzed in terms of tidal volume, expiratory time constant and series dead space. Using this data an initial ventilation pattern consisting of respiratory frequency and tidal volume was calculated. This ventilation pattern was compared to the one measured prior to the onset of the study using a two-tailed paired t-test. Additionally, it was compared to a conventional method for setting up ventilators. The computer-proposed ventilation pattern did not differ significantly from the actual pattern (p > 0.05), while the conventional method did. However the scatter was large and in 6 cases deviations in the minute ventilation of more than 50% were observed. CONCLUSIONS: The analysis of standardized Test Breaths allows automatic determination of an initial ventilation pattern for intubated ICU patients. While this pattern does not seem to be superior to the one chosen by the conventional method, it is derived fully automatically and without need for manual patient data entry such as weight or height. This makes the method potentially useful as a start up procedure for closed-loop controlled ventilation.

Clinical Disease Severity of Respiratory Viral Co-Infection versus Single Viral Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Results from cohort studies evaluating the severity of respiratory viral co-infections are conflicting. We conducted a systematic review and meta-analysis to assess the clinical severity of viral co-infections as compared to single viral respiratory infections. METHODS: We searched electronic databases and other sources for studies published up to January 28, 2013. We included observational studies on inpatients with respiratory illnesses comparing the clinical severity of viral co-infections to single viral infections as detected by molecular assays. The primary outcome reflecting clinical disease severity was length of hospital stay (LOS). A random-effects model was used to conduct the meta-analyses. RESULTS: Twenty-one studies involving 4,280 patients were included. The overall quality of evidence applying the GRADE approach ranged from moderate for oxygen requirements to low for all other outcomes. No significant differences in length of hospital stay (LOS) (mean difference (MD) -0.20 days, 95% CI -0.94, 0.53, p = 0.59), or mortality (RR 2.44, 95% CI 0.86, 6.91, p = 0.09) were documented in subjects with viral co-infections compared to those with a single viral infection. There was no evidence for differences in effects across age subgroups in post hoc analyses with the exception of the higher mortality in preschool children (RR 9.82, 95% CI 3.09, 31.20, p<0.001) with viral co-infection as compared to other age groups (I2 for subgroup analysis 64%, p = 0.04). CONCLUSIONS: No differences in clinical disease severity between viral co-infections and single respiratory infections were documented. The suggested increased risk of mortality observed amongst children with viral co-infections requires further investigation.

Exposure to bioaerosols, respiratory health and lung-specific proteins: a prospective study in garbage and wastewater workers.

Objectives To prospectively assess respiratory health in wastewater workers and garbage collectors over 5 years. Methods Exposure, respiratory symptoms and conditions, spirometry and lung-specific proteins were assessed yearly in a cohort of 304 controls, 247 wastewater workers and 52 garbage collectors. Results were analysed with random coefficient models and linear regression taking into account several potential confounders. Results Symptoms, spirometry and lung-specific proteins were not affected by occupational exposure. Conclusions In this population no effects of occupational exposure to bioaerosols were found, probably because of good working conditions.

Proportion of out-of-hospital adult non-traumatic cardiac or respiratory arrest among calls for seizure.

OBJECTIVES: To measure the proportion of adult non-traumatic cardiac or respiratory arrest among calls for seizure to an emergency medical dispatch centre and to record whether known epileptic patients present cardiac or respiratory arrest together with seizure. METHODS: This 2-year prospective observational investigation involved the collection of tape recordings of all incoming calls to the emergency medical dispatch centre, in which an out-of-hospital non-traumatic seizure was the chief complaint in patients >18 years, in addition to the paramedics' records of all patients who presented with respiratory or cardiac arrest. The authors also recorded whether the bystander spontaneously mentioned to the dispatcher that the victim was known to have epilepsy. RESULTS: During the 24-month period, the call centre received 561 incoming calls for an out-of-hospital non-traumatic seizure in an adult. Twelve cases were classified as cardiac or respiratory arrest by paramedics. In one case, the caller spontaneously mentioned that the victim had a history of epilepsy. The proportion of cardiac or respiratory arrest among calls for seizure was 2.1%. CONCLUSION: Although these cases are rare, dispatchers should closely monitor seizure patients with the help of bystanders to exclude an out-of-hospital cardiac or respiratory arrest, in which case the dispatcher can offer telephone cardiopulmonary resuscitation advice until the paramedics arrive. Whenever the activity of the centre allows it and no new incoming call is on hold, this can be achieved by staying on the line with the caller or by calling back. A history of epilepsy should not modify the type of monitoring performed by the dispatcher as those patients may also have an arrest together with seizure.