[COVID-19 associated pneumonia despite repeatedly negative PCR-analysis from oropharyngeal swabs]. / COVID-19-assoziierte Pneumonie trotz persistierend negativen PCR-Tests aus oropharyngealen Abstrichen.

PATIENT HISTORY AND CLINICAL FINDINGS: A 46-year old construction worker presented at the emergency department with two orthostatic syncopes. The patient complained of prolonged fever and coughs for 7 days which had not improved after oral treatment with sultamicillin for 5 days, prescribed by the patient's general practitioner. Physical examination showed high blood pressure due to previously known hypertension. Other vital signs without pathological findings. Pulmonary auscultation showed basal soft crackling noises of the left lung. FINDINGS AND DIAGNOSIS: Laboratory examination showed increased values for LDH, pro-BNP and CRP and normal values for leucocytes and procalcitonin. Conventional X-Ray of the chest showed bipulmonal lateral atypical infiltrates. After the first PCR turned in negative another PCR-analysis for SARS-CoV-2 of a deep oral swab-sample was performed since the clinical, laboratory and radiological findings were typical for COVID-19. Again, SARS-CoV-2-RNA was not detected. A CT-scan of the chest showed bipulmonal lateral ground-glass attenuation, again typical for COVID-19 associated pneumonia. After a third attempt for a PCR-analysis of a deep oral swab-sample was negative, analysis of a sputum was performed which finally confirmed the diagnosis of COVID-19 associated pneumonia. THERAPY AND COURSE OF EVENTS: The patient was admitted for evaluation of syncopes and suspect of COVID-19 associated pneumonia. The patient was prophylactically isolated while the result of SARS-CoV-2-PCR from a deep oral swab was pending. Suspecting a possible secondary bacterial infection at the beginning, intravenous antibiotic treatment with ampicillin/sulbactam was initiated. While further examinations showed no indication for bacterial infection, antibiotics were discontinued after 3 days. Due to clinical recovery antiviral therapy was not performed after confirming the diagnosis. The patient was discharged 17 days after onset of first symptoms without any requirements for further isolation. CONCLUSION: This casuistic describes a case of COVID-19 associated pneumonia presenting with typical clinical features, laboratory and radiological findings. Detection of viral RNA was not successful from deep oral swab-samples despite repeated attempts. Finally, PCR-analysis of sputum confirmed the diagnosis. Analysis of deeper airway samples (sputum, bronchoalveolar lavage, tracheal secretions) or stool for SARS-CoV-2 should be performed in cases of evident clinical suspicion of COVID-19 and negative PCR results from deep oral swabs.

[Severe lymphopenia in a patient with Crohn's disease]. / Schwere Lymphozytopenie bei Patientin mit Morbus Crohn.

We report on a 25-year-old female patient with Crohn's disease and profound lymphocytopenia while receiving corticosteroids and azathioprine. Discontinuation of azathioprine only resulted in a mild increase in CD4+ T cell numbers; however, therapy with the TNFα inhibitor adalimumab was initiated for a clinical flare and resulted in long-lasting clinical remission and rapid normalization of the lymphocytopenia including the respective lymphocyte subsets. Lymphocytopenia is frequently observed as a side effect of immunosuppressive therapy. This case illustrates that lymphocytopenia may also occur in relation to Crohn's disease activity as an extraintestinal manifestation and may then be efficiently treated by escalation of immunosuppressive therapy.

Active transport in dense diffusive single-file systems.

We study a minimal model of active transport in crowded single-file environments which generalizes the emblematic model of single-file diffusion to the case when the tracer particle (TP) performs either an autonomous directed motion or is biased by an external force, while all other particles of the environment (bath) perform unbiased diffusions. We derive explicit expressions, valid in the limit of high density of bath particles, of the full distribution P((n))(X) of the TP position and of all its cumulants, for arbitrary values of the bias f and for any time n. Our analysis reveals striking features, such as the anomalous scaling [proportionality] √[n] of all cumulants, the equality of cumulants of the same parity characteristic of a Skellam distribution and a convergence to a Gaussian distribution in spite of asymmetric density profiles of bath particles. Altogether, our results provide the full statistics of the TP position and set the basis for a refined analysis of real trajectories of active particles in crowded single-file environments.

Obstructive sleep apnoea and metabolic impairment in severe obesity.

Obstructive sleep apnoea (OSA) seems to worsen metabolism. This effect has not been evaluated in morbid obesity (MO). We hypothesised that the metabolic profile is more impaired in MO patients with OSA than in those without, and investigated whether any specific metabolic dysfunction is related to OSA in MO. A prospective multicentre cross-sectional study was conducted in consecutive subjects before bariatric surgery. OSA was defined as apnoea/hypopnoea index (AHI) ≥15 by overnight polysomnography. Anthropometrical, blood pressure (BP) and fasting blood measurements were obtained the morning after. Metabolic syndrome (MetS) was defined according to National Cholesterol Education Program Adult Treatment Panel III modified criteria. 159 patients were studied: 72% were female and 72% had OSA. MetS prevalence was 70% in OSA versus 36% in non-OSA (p<0.001). As AHI severity increased, metabolic parameters progressively worsened, even in those without type 2 diabetes (DM2). AHI was independently associated with systolic and diastolic BP, triglycerides and the percentage of glycosylated haemoglobin (HbA1c) in the total sample, and with systolic BP, high-density lipoprotein cholesterol and HbA1c in those samples without DM2. OSA increased the adjusted odds ratio of having MetS by 2.8 (95% CI 1.3-6.2; p=0.009). In MO, OSA is associated with major metabolic impairment caused by higher BP and poorer lipid and glucose control, independent of central obesity or DM2.

Noninvasive positive pressure ventilation prevents postoperative pulmonary complications in chronic ventilators users.

OBJECTIVE: To evaluate the postoperative pulmonary complications and the long-term impact on pulmonary function of different surgical procedures with general anaesthesia in chronic respiratory failure (CRF) patients who were using noninvasive positive pressure ventilation (NPPV). DESIGN: We retrospectively studied 20 stable patients on NPPV for CRF secondary to: kyphoscoliosis (eight), morbid obesity (six), thoracoplasty (four), neuromuscular diseases (two), who underwent surgical procedures with general anaesthesia, between January 1998 and December 2003. MATERIAL AND METHODS: The variables studied were: type of surgery, hours of orotracheal intubation, hours of stay in the postsurgical reanimation unit (PRU), postoperative pulmonary complications and days of hospital stay. These results were compared with those obtained in patients without respiratory pathology and who were submitted to the same type of surgical interventions during the study period. All patients were tested for: arterial blood gases, forced vital capacity (FVC) and forced expiratory volume in 1s (FVE1). These tests were carried out both prior to surgical intervention and 12 months after this intervention, and the use of medical assistance resources the year prior to and the year after the surgical intervention were also analysed. RESULTS: Sixteen patients were using NPPV at home at the time of the intervention and four patients were adapted to NPPV before surgery. The surgical procedures were: gastroplasty: six; mastectomy: five; septoplasty: three; hip prosthesis: two; cholecystectomy: one; Gasserian ganglion thermocoagulation: one; hysterectomy: one; and endoscopic retrograde cholangiopancreatography (ERCP): one. The mean postoperative intubation time was 3.8+/-3.2h, and only one patient remained intubated for more than 12h. The mean stay in the PRU was 19+/-9h (vs 19+/-6h in the general population, p>0.05). The days of hospital stay for the different pathologies were in the majority of cases greater than in the general population. We did not find significant differences on comparing the arterial blood gases, in pulmonary function or in use of assistance resources between the year previous to and the year following the surgical intervention. CONCLUSIONS: In high-risk patients with chronic respiratory failure as a consequence of a restrictive lung pathology, NPPV can play an important role to confront surgical procedure with general anaesthesia with greater security. To obtain these results, it was fundamental to coordinate between the Pulmonary Services and the Anaesthesia Services as well as to follow up jointly in the PRU.

Long-term mechanical ventilation in amyotrophic lateral sclerosis.

BACKGROUND: Acute respiratory insufficiency (ARI) with alveolar hypoventilation or incapacitating dyspnoea but without peripheral muscle involvement can be an early manifestation of respiratory involvement in amyotrophic lateral sclerosis (ALS). Some of these patients benefit from assisted ventilation. The object of this study was to analyse the results of long-term mechanical ventilation (LTMV) in ten patients with ALS. METHODS: A retrospective analysis of intensive care unit (ICU) or ambulant patients with ALS who underwent LTMV in a conventional hospital ward was performed. Erect and supine spirometry, blood gas analysis and pulse oximetry were performed before the start and during the course of ventilation. RESULTS: Ten patients on LTMV were included. Four from the ICU were ventilated via tracheostomy, and six ambulant patients had non-invasive (nasal) ventilation. In all cases, ventilation was performed in a conventional hospital ward. The ambulant patients improved symptomatically during ventilation, confirmed by measurement of gas exchange and of SaO2 by continuous pulse oximetry. Three of the ten patients survive in long-term care--two with nasal and one with tracheostomy ventilation. CONCLUSIONS: LTMV outside ICU was possible in ten patients, seven of whom returned home. Returning home is very difficult for patients dependent on a ventilator who lack family support.

[Effectiveness of a mandibular advancement prosthesis in the treatment of obstructive sleep apnea syndrome]. / Eficacia de una prótesis de avance mandibular en el tratamiento del síndrome de apneas obstructivas del sueño.

OBJECTIVE: To assess the efficacy of a mandibular advancement prosthesis for treating obstructive sleep apnea syndrome (OSAS). METHOD: Mandibular advancement appliances were prescribed for 21 patients (20 men) with OSAS diagnosed by polysomnography. Mean age was 51 (8) years, BMI was 30 (4) kg/m2, and the apnea-hypopnea index (AHI) per hour was 48 (17). If the device was well tolerated, regardless of clinical response, polysomnography was repeated between 1 to 3 months after start of treatment. The device was considered effective if the AHI decreased to < 15/h and symptoms related to OSAS disappeared. RESULTS: Seven patients withdrew from treatment after only a few days. The remaining 14 (66%) tolerated treatment well and the second polysomnogram was performed. In six of the 14 (43%), the device proved effective for correcting OSAS. In six more patients, the AHI decreased but failed to become normal. In the remaining two patients, no improvement was observed. Improvement in the AHI was unrelated to severity of OSAS. CONCLUSION: The mandibular advancement prosthesis is effective for some patients with OSAS, including those in whom the AHI is high. Larger studies are needed to allow us to define the type of patients that might benefit.

[The evaluation of the oxygen-conserving valve during exertion]. / Evaluación de la válvula ahorradora de oxígeno durante el esfuerzo.

BACKGROUND: The oxygen-conserving valve (OCV) permits reduction in oxygen consumption upon the release of oxygen only during inhalation thereby increasing the autonomy of portable sources. METHODS: In order to confirm its efficacy during exercise, 15 patients with chronic limitation of air flow and gasometric criteria of domiciliary oxygen therapy were selected. The patients underwent three walking tests (WT) of 6 minutes during which the continuous form of transcutaneous hemoglobin saturation (SaO2) and the distance covered were registered. The first was carried out breathing synthetic air at a flow of 2 liters per minute; the second with continuous oxygen released by a portable source at 2 liters per minute and the third with the OCV coupled to a portable source at the same flow. RESULTS: SaO2 reached with the continuous oxygen is significantly higher to that of synthetic air while there was no difference between the SaO2 with continuous oxygen and with valve. Improvement in SaO2 upon use the valve was not obtained in only 2 of the 15 patients. A significant increase was observed in the distance covered upon oxygen administration not only in the continuous form but also with OCV with respect to synthetic air. CONCLUSIONS: OCV is as effective as continuous oxygen in the correction of desaturation during exercise, however its indications must be individualized by exercise tests (WT) in each patients in order to ensure its correct functioning.

[The introduction of liquid oxygen as a portable source in continuous home oxygen therapy]. / Introducción del oxígeno líquido como fuente portátil en la oxigenoterapia continua domiciliaria.

The most widespread types of oxygen delivery at home in our area are bottles where the gas is stored under pressure and concentrators. Both devices can only be used at rest. We have assessed a new system for the delivery of liquid oxygen to be used at home, provided with a portable unit which permits that the patients receive oxygen also outside their homes. Seven such devices have been implemented in the Barcelona area, with an excellent acceptance and without technical problems. To verify the clinical indication, exercise tests were carried out both in baseline conditions and receiving oxygen from the portable source. Oxyhemoglobin saturation and the walked distance were continuously measured. In all patients important drops in the saturation of oxyhemoglobin were recorded during walking, which was corrected with oxygen administration. Liquid oxygen with a portable source is a good delivery system for oxygen therapy at home, permitting to receive oxygen throughout the day, particularly during exercise. Although the availability of liquid oxygen is limited, it should be recommended to the patients in whom exercise hypoxemia is shown to be corrected and who desire an active social life.

[Measurement of the perceived impact of sleep problems: the Spanish version of the functional outcomes sleep questionnaire and the Epworth sleepiness scale]. / Medida del impacto de los trastornos del sueño: las versiones españolas del cuestionario del impacto funcional del sueño y de la escala de somnolencia de Epworth.

BACKGROUND: Excessive daytime sleepiness is a frequent symptom and a public health problem due to its association with automobile and work related accidents. The aim of this study was to develop and carry out a preliminary assessment of the Spanish version of the functional outcomes sleep questionnaire and the Epworth sleepiness scale, two instruments designed to evaluate patients with sleep disorders. MATERIAL AND METHODS: For the adaptation, the forward and back-translation method by bilinguals was used with professional and lay panel. Once tested for feasibility and comprehension, 39 patients with obstructive sleep apnea syndrome completed the Spanish version of the FOSQ and the Epworth sleepiness scale, together with a question on self-rated health status. RESULTS: Difficulty of translation was assessed as low and the naturalness of Spanish expressions as high for all the items of the questionnaires except for the response options of the Epworth sleepiness scale. Both questionnaires showed higher reliability than the standard proposed for individual comparisons (Cronbach's alpha > 0.9). The FOSQ vigilance scale showed a high correlation with the Epworth score (r = -0.79), while for the other scales of the FOSQ correlations were moderate (r ranging from -0.52 to -0.68). Patients who reported "regular" or "poor" health had significantly worse scores for most of the FOSQ scales. CONCLUSION: These results suggest that the Spanish versions of both questionnaires are conceptually equivalent to the originals and that they show similar characteristics of reliability and validity. The FOSQ vigilance scale assess daytime sleepiness similarly to Epworth but the others scales of the FOSQ provide additional information for these patients.

Symmetry breaking between statistically equivalent, independent channels in few-channel chaotic scattering.

We study the distribution function P(ω) of the random variable ω=τ(1)/(τ(1)+···+τ(N)), where τ(k)'s are the partial Wigner delay times for chaotic scattering in a disordered system with N independent, statistically equivalent channels. In this case, τ(k)'s are independent and identically distributed random variables with a distribution Ψ(τ) characterized by a "fat" power-law intermediate tail ~1/τ(1+µ), truncated by an exponential (or a log-normal) function of τ. For N=2 and N=3, we observe a surprisingly rich behavior of P(ω), revealing a breakdown of the symmetry between identical independent channels. For N=2, numerical simulations of the quasi-one-dimensional Anderson model confirm our findings.

Coupled normal heat and matter transport in a simple model system.

We introduce the first simple mechanical system that shows fully realistic transport behavior while still being exactly solvable at the level of equilibrium statistical mechanics. The system is a Lorentz gas with fixed freely rotating circular scatterers which scatter point particles via perfectly rough collisions. Upon imposing either a temperature gradient and/or a chemical potential gradient, a stationary state is attained for which local thermal equilibrium holds. Transport in this system is normal in the sense that the transport coefficients which characterize the flow of heat and matter are finite in the thermodynamic limit. Moreover, the two flows are nontrivially coupled, satisfying Onsager's reciprocity relations.

Spectroscopic interpretation: the high vibrations of CDBrClF.

We extract the dynamics implicit in an algebraic fitted model Hamiltonian for the deuterium chromophore's vibrational motion in the molecule CDBrClF. The original model has four degrees of freedom, three positions and one representing interbond couplings. A conserved polyad allows in a semiclassical approach the reduction to three degrees of freedom. For most quantum states we can identify the underlying motion that when quantized gives the said state. Most of the classifications, identifications, and assignments are done by visual inspection of the already available wave function semiclassically transformed from the number representation to a representation on the reduced dimension toroidal configuration space corresponding to the classical action and angle variables. The concentration of the wave function density to lower dimensional subsets centered on idealized simple lower dimensional organizing structures and the behavior of the phase along such organizing centers already reveals the atomic motion. Extremely little computational work is needed.

Effectiveness of continuous positive airway pressure in mild sleep apnea-hypopnea syndrome.

The aim of this trial was to evaluate the effectiveness of continuous positive airway pressure (CPAP) in patients with mild sleep apnea- hypopnea syndrome (SAHS). One hundred forty-two consecutive patients with mild SAHS (apnea-hypopnea index 10-30, without severe sleepiness) were randomly assigned to receive conservative treatment (CT)-sleep hygiene and weight loss-(65 patients) or CT plus CPAP (77 patients), and 125 patients (86% males, age: 54 +/- 9 yr, BMI: 29 +/- 4 kg/m(2), AHI: 20 +/- 6, ESS: 12 +/- 4) completed the follow-up. The following outcomes were assessed at inclusion and after 3 and 6 mo of treatment: sleepiness (Epworth scale, multiple sleep latency test [MSLT]), other symptoms related to SAHS, cognitive function, and perceived health status (Functional Outcomes of Sleep Questionnaire [FOSQ], Nottingham Health profile). The relief of SAHS-related clinical symptoms was significantly greater in the CPAP group than in the CT group; the Epworth scale and FOSQ also showed more improvement in the CPAP group but did not reach significance. There were no significant differences in the other tests performed probably because the baseline values were normal. CPAP compliance was 4.8 +/- 2.2 h and treatment continuation was accepted by 62% of the patients at the end of the study. These results suggest that CPAP can be considered in treating patients with mild SAHS on the basis of an improvement in symptoms.

First experimental evidence for quantum echoes in scattering systems.

A self-pulsing effect termed quantum echoes has been observed in experiments with an open superconducting and a normal conducting microwave billiard whose geometry provides soft chaos, i.e., a mixed phase space portrait with a large stable island. For such systems a periodic response to an incoming pulse has been predicted. Its period has been associated with the degree of development of a horseshoe describing the topology of the classical dynamics. The experiments confirm this picture and reveal the topological information.