The role of high flow oxygen therapy in acute respiratory failure.

Acute respiratory failure represents one of the most common causes of intensive care unit admission and oxygen therapy remains the first-line therapy in the management of these patients. In recent years, high-flow oxygen via nasal cannula has been described as a useful alternative to conventional oxygen therapy in patients with acute respiratory failure. High-flow oxygen via nasal cannula rapidly alleviates symptoms of acute respiratory failure and improves oxygenation by several mechanisms, including dead space washout, reduction in oxygen dilution and inspiratory nasopharyngeal resistance, a moderate positive airway pressure effect that may generate alveolar recruitment and an overall greater tolerance and comfort with the interface and the heated and humidified inspired gases. However, the experience in adults is still limited and there are no clinical guidelines to establish recommendations for their use. This article aims to review the existing evidence on the use of high-flow oxygen via nasal cannula in adults with acute respiratory failure and its possible applications, advantages and limitations.

Bronchial inflammation and hyperresponsiveness in well controlled asthma.

BACKGROUND: Little research has been devoted to the characteristics of bronchial inflammation in patients with stable, well controlled asthma. OBJECTIVE: The aim of this study was to assess the degree and type of airway inflammation and to investigate the relationship between inflammation and bronchial hyperresponsiveness in patients with well controlled asthma. METHODS: A cross-sectional study was conducted in 84 adult patients (43 men, mean age 43 years) with documented well controlled asthma. Induced sputum samples were obtained and cell types determined by differential cell count. Spirometry and methacholine challenge testing were performed. Asthma Control Questionnaire (ACQ) was used to assess symptoms. Patients were included if their ACQ score was < 0.75. RESULTS: A total of 59 patients had persistent bronchial inflammation: 28 cases were considered eosinophilic, 28 neutrophilic, and 3 mixed. Median (range) percentage of eosinophils was 4% (0-64) in patients testing positive to methacholine challenge (n = 66) and 1% (0-3) in those testing negative (n = 18) (P = 0.003). A positive correlation was found between eosinophil percentage and the methacholine dose/response ratio (r = 0.477, P = 0.0001). The geometric mean (95% CI) of the methacholine PC20 was 1.74 mg/mL (1.04-2.93) in patients with eosinophilic inflammation and 4.14 mg/mL (2.5-6.84) in those with neutrophilic inflammation (P = 0.03). CONCLUSIONS: Inflammation and bronchial hyperresponsiveness persist in most patients with well controlled asthma. CLINICAL RELEVANCE: The study demonstrates that eosinophilic or neutrophilic inflammation persisted in most well controlled asthma patients despite the fact that their condition was controlled and therefore, measurement of bronchial inflammation seems essential to achieve proper asthma control.

Utility of exhaled breath condensate pH for diagnosing occupational asthma.

INTRODUCTION: The current reference standard method for diagnosing occupational asthma (OA) is specific inhalation challenge (SIC) with the suspected agent. The alternative method is serial peak expiratory flow (PEF) monitoring. Nevertheless, PEF does not have optimal sensitivity and specificity for this purpose. The aim of this study was to evaluate the utility of exhaled breath condensate (EBC) pH for the diagnosis of OA. MATERIAL AND METHODS: A prospective study was performed in 37 subjects with suspected OA. Serial PEF monitoring was carried out for 2 weeks at work and for 2 weeks off work. At the end of each period, the EBC pH and the methacholine concentration resulting in a 20% FEV(1) decrease (PC20) were measured. SIC was subsequently performed. PEF graphs were interpreted visually by 3 experienced independent readers. RESULTS: Seventeen patients tested positive with SIC. Receiver-operating characteristic curves showed that a decrease in EBC pH greater than 0.4 units during the period at work compared to the off-work period achieved the most satisfactory sensitivity (40%, CI 19.4-66.5) and specificity (90%, CI 66.9-98.2) for diagnosing OA. When EBC pH findings were added to PEF results, the diagnostic yield of PEF generally increased. Other test combinations (e.g. EBC pH plus PC20 or EBC pH plus PC20 plus PEF) did not improve diagnostic performance. CONCLUSIONS: Acidification of EBC pH at work and adding the EBC pH measurement to PEF monitoring during periods at work and off work may be useful for improving the diagnosis of OA.

Solid organ transplant training objectives for residents.

With the aim of analyzing the current state of the educational objectives in the training of medical residents in solid organ transplantation (SOT), we conducted a review of the status of the official programs of the specialities involved in SOT, focusing particularly on lung transplantation. A survey of medical residents was also conducted to allow reflexion about the topic. We obtained 44 surveys from 4 University Hospitals with active programs in SOT, mainly from intensive care medicine and anesthesiology residents. We detected an important number of courses oriented to organ donation but very limited in terms of basic training in the management of the immediate postoperative period, principles of immunosuppression and updates on immunosuppressive therapy and complications (particularly rejection and infection). We also identified that these educational aspects should be directed not only to medical residents from specialities with a close retation to SOT, but also to all who may at some time have a relation to such patients. The use of information and communication techniques (ICTs), on-line courses and also simulations should be instruments to take into account in the biomedical training of medical residents. We conclude that we need a specific training program in complications of SOT, as well as fundamental principles in immunology and immunosuppressor pharmacology.

Hyperoxemia in invasively ventilated COVID-19 patients-Insights from the PRoVENT-COVID study.

OBJECTIVE: We determined the prevalences of hyperoxemia and excessive oxygen use, and the epidemiology, ventilation characteristics and outcomes associated with hyperoxemia in invasively ventilated patients with coronavirus disease 2019 (COVID-19). METHODS: Post hoc analysis of a national, multicentre, observational study in 22 ICUs. Patients were classified in the first two days of invasive ventilation as 'hyperoxemic' or 'normoxemic'. The co-primary endpoints were prevalence of hyperoxemia (PaO2 > 90 mmHg) and prevalence of excessive oxygen use (FiO2 ≥ 60% while PaO2 > 90 mmHg or SpO2 > 92%). Secondary endpoints included ventilator settings and ventilation parameters, duration of ventilation, length of stay (LOS) in ICU and hospital, and mortality in ICU, hospital, and at day 28 and 90. We used propensity matching to control for observed confounding factors that may influence endpoints. RESULTS: Of 851 COVID-19 patients, 225 (26.4%) were classified as hyperoxemic. Excessive oxygen use occurred in 385 (45.2%) patients. Acute respiratory distress syndrome (ARDS) severity was lowest in hyperoxemic patients. Hyperoxemic patients were ventilated with higher positive end-expiratory pressure (PEEP), while rescue therapies for hypoxemia were applied more often in normoxemic patients. Neither in the unmatched nor in the matched analysis were there differences between hyperoxemic and normoxemic patients with regard to any of the clinical outcomes. CONCLUSION: In this cohort of invasively ventilated COVID-19 patients, hyperoxemia occurred often and so did excessive oxygen use. The main differences between hyperoxemic and normoxemic patients were ARDS severity and use of PEEP. Clinical outcomes were not different between hyperoxemic and normoxemic patients.

Awake prone positioning in nonintubated spontaneous breathing ICU patients with acute hypoxemic respiratory failure (PRONELIFE)-protocol for a randomized clinical trial.

BACKGROUND: It is uncertain whether awake prone positioning can prevent intubation for invasive ventilation in spontaneous breathing critically ill patients with acute hypoxemic respiratory failure. Awake prone positioning could benefit these patients for various reasons, including a reduction in direct harm to lung tissue, and prevention of tracheal intubation-related complications. DESIGN AND METHODS: The PRONELIFE study is an investigator-initiated, international, multicenter, randomized clinical trial in patients who may need invasive ventilation because of acute hypoxemic respiratory failure. Consecutive patients admitted to participating ICUs are randomly assigned to standard care with awake prone positioning, versus standard care without awake prone positioning. The primary endpoint is a composite of tracheal intubation and all-cause mortality in the first 14 days after enrolment. Secondary endpoints include time to tracheal intubation and effects of awake prone positioning on oxygenation parameters, dyspnea sensation, and complications. Other endpoints are the number of days free from ventilation and alive at 28 days, total duration of use of noninvasive respiratory support, total duration of invasive ventilation, length of stay in ICU and hospital, and mortality in ICU and hospital, and at 28, 60, and 90 days. We will also collect data regarding the tolerance of prone positioning. DISCUSSION: The PRONELIFE study is among the first randomized clinical trials investigating the effect of awake prone positioning on intubation rate in ICU patients with acute hypoxemic failure from any cause. The PRONELIFE study is sufficiently sized to determine the effect of awake prone positioning on intubation for invasive ventilation-patients are eligible in case of acute hypoxemic respiratory failure without restrictions regarding etiology. The PRONELIFE study is a pragmatic trial in which blinding is impossible-however, as around 35 ICUs worldwide will participate in this study, its findings will be highly generalizable. The findings of the PRONELIFE study have the potential to change clinical management of patients who may need invasive ventilation because of acute hypoxemic respiratory failure. TRIAL REGISTRATION: ISRCTN ISRCTN11536318 . Registered on 17 September 2021. The PRONELIFE study is registered at clinicaltrials.gov with reference number NCT04142736 (October, 2019).

A prospective international observational prevalence study on prone positioning of ARDS patients: the APRONET (ARDS Prone Position Network) study.

INTRODUCTION: While prone positioning (PP) has been shown to improve patient survival in moderate to severe acute respiratory distress syndrome (ARDS) patients, the rate of application of PP in clinical practice still appears low. AIM: This study aimed to determine the prevalence of use of PP in ARDS patients (primary endpoint), the physiological effects of PP, and the reasons for not using it (secondary endpoints). METHODS: The APRONET study was a prospective international 1-day prevalence study performed four times in April, July, and October 2016 and January 2017. On each study day, investigators in each ICU had to screen every patient. For patients with ARDS, use of PP, gas exchange, ventilator settings and plateau pressure (Pplat) were recorded before and at the end of the PP session. Complications of PP and reasons for not using PP were also documented. Values are presented as median (1st-3rd quartiles). RESULTS: Over the study period, 6723 patients were screened in 141 ICUs from 20 countries (77% of the ICUs were European), of whom 735 had ARDS and were analyzed. Overall 101 ARDS patients had at least one session of PP (13.7%), with no differences among the 4 study days. The rate of PP use was 5.9% (11/187), 10.3% (41/399) and 32.9% (49/149) in mild, moderate and severe ARDS, respectively (P = 0.0001). The duration of the first PP session was 18 (16-23) hours. Measured with the patient in the supine position before and at the end of the first PP session, PaO2/FIO2 increased from 101 (76-136) to 171 (118-220) mmHg (P = 0.0001) driving pressure decreased from 14 [11-17] to 13 [10-16] cmH2O (P = 0.001), and Pplat decreased from 26 [23-29] to 25 [23-28] cmH2O (P = 0.04). The most prevalent reason for not using PP (64.3%) was that hypoxemia was not considered sufficiently severe. Complications were reported in 12 patients (11.9%) in whom PP was used (pressure sores in five, hypoxemia in two, endotracheal tube-related in two ocular in two, and a transient increase in intracranial pressure in one). CONCLUSIONS: In conclusion, this prospective international prevalence study found that PP was used in 32.9% of patients with severe ARDS, and was associated with low complication rates, significant increase in oxygenation and a significant decrease in driving pressure.

The Role of Omega-3 Polyunsaturated Fatty Acids in the Treatment of Patients with Acute Respiratory Distress Syndrome: A Clinical Review.

Acute respiratory distress syndrome (ARDS) is defined as the acute onset of noncardiogenic edema and subsequent gas-exchange impairment due to a severe inflammatory process. Recent report on the prognostic value of eicosanoids in patients with ARDS suggests that modulating the inflammatory response through the use of polyunsaturated fatty acids may be a useful strategy for ARDS treatment. The use of enteral diets enriched with eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA) has reported promising results, showing an improvement in respiratory variables and haemodynamics. However, the interpretation of the studies is limited by their heterogeneity and methodology and the effect of ω-3 fatty acid-enriched lipid emulsion or enteral diets on patients with ARDS remains unclear. Therefore, the routine use of ω-3 fatty acid-enriched nutrition cannot be recommended and further large, homogeneous, and high-quality clinical trials need to be conducted to clarify the effectiveness of ω-3 polyunsaturated fatty acids.

Intravascular and sclerosing bronchio-alveolar tumor.

A case of intravascular and sclerosing bronchio-alveolar tumor is presented with ultrastructural observations. The tumor cells appear to arise from the alveolar lining and are characterized by a fibrillary cytoplasm. These cells are enmeshed in interstitial tissue containing fibrils, elastin material, amorphous intercellular substance and degenerated cytoplasmic processes. The patient, a 49-year-old white woman, is alive without treatment, with no significant increase in size or number of lung nodules 7 years after the clinical discovery.

Restrictive cardiomyopathy in pseudoxanthoma elasticum.

A unique case of severe and diffuse endocardial fibroelastosis covering the entire left ventricle and associated with pseudoxanthoma elasticum is presented. The clinical picture was that of an apparently primary restrictive cardiomyopathy. Specific histologic lesions could be recognized in the endocardium.

Translocation (5;19)(q13;q13) in a multinodular thyroid goiter.

We describe the cytogenetics of a multinodular thyroid goiter where 90% of the analyzed cells showed a diploid karyotype with a balanced translocation between chromosomes 5 and 19: 46,XX,t(5;19)(q13;q13). This translocation has been previously described in cases of thyroid adenoma. Our case is the first report of this anomaly in nodular hyperplasia. We discuss its putative role in the neoplastic transformation of thyroid lesions.

Nuclear chromatin texture to differentiate follicular and papillary carcinoma of the thyroid.

This study presents the results of an automatic classification of six purely papillary, five purely follicular and five mixed papillary-follicular carcinomas of the thyroid. All cases were correctly classified with only two chromatin textural parameters obtained in the Olga's scan software package developed in our laboratory. Chromatin texture lines were generated by a unidirectional grey level gradient, obtained as a natural logarithmic function of the integrated optical density of each nucleus; this increased the difference between clear papillary and granular follicular nuclei. The accuracy of the method allowed a follicular carcinoma to be correctly classified as a mixed follicular-papillary. Finally a columnar-cell carcinoma of the thyroid was detected by means of its atypical DNA histogram.

Massive articular chondrocalcinosis. Its occurrence with calcium pyrophosphate crystal deposits in nucleus pulposus.

We studied a case of long-standing chondrocalcinosis that after 40 years affected almost all fibrocartilages, hyaline cartilages, and articular cavities within the subject. Massive deposits of dihydrocalcium pyrophosphate (CPP) were also found in nonfissured nucleus pulposus of the vertebral disks. To our knowledge, this is the first report of CPP deposits in these disks.

Virtual sonography through the Internet: volume compression issues.

BACKGROUND: Three-dimensional ultrasound images allow virtual sonography even at a distance. However, the size of final 3-D files limits their transmission through slow networks such as the Internet. OBJECTIVE: To analyze compression techniques that transform ultrasound images into small 3-D volumes that can be transmitted through the Internet without loss of relevant medical information. METHODS: Samples were selected from ultrasound examinations performed during, 1999-2000, in the Obstetrics and Gynecology Department at the University Hospital in La Laguna, Canary Islands, Spain. The conventional ultrasound video output was recorded at 25 fps (frames per second) on a PC, producing 100- to 120-MB files (for from 500 to 550 frames). Processing to obtain 3-D images progressively reduced file size. RESULTS: The original frames passed through different compression stages: selecting the region of interest, rendering techniques, and compression for storage. Final 3-D volumes reached 1:25 compression rates (1.5- to 2-MB files). Those volumes need 7 to 8 minutes to be transmitted through the Internet at a mean data throughput of 6.6 Kbytes per second. At the receiving site, virtual sonography is possible using orthogonal projections or oblique cuts. CONCLUSIONS: Modern volume-rendering techniques allowed distant virtual sonography through the Internet. This is the result of their efficient data compression that maintains its attractiveness as a main criterion for distant diagnosis.

A four-year study of telephone support for oncology patients using a non-supervised call centre.

A non-supervised call centre was used to allow oncology patients to contact their personal doctors 24 hours a day. Incoming patient calls to the centre were automatically routed to the doctor's mobile phone or office telephone. Over four years, an average of 407 calls were made each year, by an average of 274 oncology patients. The average number of emergency hospital visits was 24 per year (0.09 per patient), compared with 42 per year (0.16 per patient) during the year before the telephone service began. The average number of outreach visits was 783 (2.9 per patient) per year during the study, in comparison with 722 (2.8 per patient) before it began. The average number of non-emergency hospital admissions was 41 (0.15 per patient) per year in comparison with 42 (0.17 per patient) before the study. Calls were short (typically 3-5 min) and the majority (88%) were made on the patient's initiative. Outreach patients in receipt of chemotherapy were the principal users (making 88% of all calls). Excluding the initial investment cost, the income received was approximately the same as the running costs of the call centre in two of the three years for which data were available.

The environment for telemedicine in the Canary Islands.

We studied the environment for telemedicine in the Canary Islands. The population's attitude to telemedicine was surveyed in 503 questionnaire interviews with doctors, nurses, paramedical staff and patients on the seven islands. Almost half the respondents (46-50% across groups) had a positive opinion of telemedicine. We also collected data about telephone medicine. A total of 479 medical-support telephone calls were made to four doctors, in psychiatry, ophthalmology and paediatrics. The telephone calls resolved the problem in 73% of cases and 86% would have come to the doctor if not made. Therapy was prescribed in 11% and 10% were just for information. The number of telephone calls per day was highest in psychiatry. Finally, we carried out a detailed analysis of the number of transfers between the islands (14,942 people in 1995 and 22,418 in 1996). According to the number of transfers and location of the referral hospital, oncology, psychiatry, dermatology and traumatology were the specialties that would be most likely to benefit from telemedicine.

Mobile phone text messaging in the management of diabetes.

We conducted a trial of mobile phone text messaging (short message service; SMS) for diabetes management. In an eight-month period, 23 diabetic patients used the service. Patients used SMS to transmit data such as blood glucose levels and body weight to a server. The server automatically answered with an SMS acknowledgement message. A monthly calculated glycosylated haemoglobin result was also automatically sent to the patient by SMS. During the trial the patients sent an average of 33 messages per month. Although users showed good acceptance of the SMS diabetes system, they expressed various concerns, such as the inability to enter data from previous days. Nonetheless, the trial results suggest that SMS may provide a simple, fast and efficient adjunct to the management of diabetes. It was particularly useful for elderly persons and teenagers, age groups that are known to have difficulty in controlling their diabetes.

What do physicians think of telemedicine? A survey in different European regions.

To discover the perception of telemedicine in a sample of physicians not yet participating in telemedicine networks, a questionnaire was sent to doctors in different European countries. The questions covered various general aspects of telemedicine. The percentage of questionnaires returned ranged from 12% (Central Europe) to 27% (Spain). Apart from the rather disappointing response rates the results document a strong interest in telemedicine on the part of the physicians surveyed. Knowledge of the existence of telemedicine was high. Most of the respondents would have liked to have had their clinic's telemedicine system in their own laboratory. More than 50% of the physicians thought that their work would be improved by using telemedicine. Respondents from Central Europe were significantly less enthusiastic about telemedicine than those from other regions. However, the answers to the majority of the questions were similar in the different groups.