Large quantities of mineral dust particles are frequently ejected into the atmosphere through the action of wind. The surface of dust particles acts as a sink for many gases, such as sulfur dioxide. ...It is well known that under most conditions, sulfur dioxide reacts on dust particle surfaces, leading to the production of sulfate ions. In this report, for specific atmospheric conditions, we provide evidence for an alternate pathway in which a series of reactions under solar UV light produces first gaseous sulfuric acid as an intermediate product before surface-bound sulfate. Metal oxides present in mineral dust act as atmospheric photocatalysts promoting the formation of gaseous OH radicals, which initiate the conversion of SO 2 to H 2 SO 4 in the vicinity of dust particles. Under low dust conditions, this process may lead to nucleation events in the atmosphere. The laboratory findings are supported by recent field observations near Beijing, China, and Lyon, France.
Previous randomized controlled trials (RCTs) suggest that auricular stimulation (AS) is safe and effective in treatment of preoperative anxiety; however, a systematic evaluation is lacking. The aim ...was to summarize the evidence on efficacy and safety of AS for preoperative anxiety, as well as for other outcomes.
We conducted a systematic review of RCTs including patients from all available populations. The search was done through MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science and Scopus Database from inception to June 2020. Study selection and data extraction were performed in by 2 independent reviewers with ability to resolve disagreements by a third author. Meta-analyses as well as the risk of bias and evidence quality assessments were performed according to the Cochrane 6.2, 2021 handbook recommendations.
We compared AS with pharmacological and non-pharmacological interventions for different outcomes.
We assessed the repercussion of the evaluated interventions over anxiety scores and their safety, physiological parameters, perioperative medications requirement and intensity of postoperative pain.
We have included 15 studies with 1603 patients. AS has presented reduced anxiety scores as compared to the sham control (Standardized Mean Difference (SMD) -0.72, 95% confidence interval (CI) -1.09 to −0.36, p < 0.0001; 8 trials; 701 patients; heterogeneity: I2 80%; GRADE: moderate certainty) and to no intervention (SMD -1.01, 95% CI -1.58 to −0.45, p = 0.0004; 4 trials; 420 patients; heterogeneity: I2 84%; GRADE: very low certainty). There was no difference between AS and benzodiazepines (SMD -0.03; 95% CI: −0.34 to 0.28; p = 0.84; 3 trials; 158 patients; heterogeneity: I2 0%; GRADE: very low certainty). No trials reported serious adverse effects of AS.
AS may be useful in treatment of preoperative anxiety. Due to heterogenous certainty in effect estimates, further research is needed to clarify the actual efficacy of AS for preoperative anxiety.
•Auricular stimulation (AS) of cranial nerves is promising in treatment of preoperative anxiety•Anxiolytic effect of AS was better than that of control procedures and was comparable with benzodiazepines•Due to heterogenous certainty in effect estimates, large trials are needed to confirm the benefit of AS
The Campaigns of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing‐2006) were mainly focused on the influence of the regional aerosol on the air pollution in Beijing. The urban ...aerosol was characterized in detail. The particle size distributions were also compared to those measured at a regional site (Yufa) approximately 50 km south of the urban site at Peking University (PKU). At PKU, total particle number and volume concentrations were (1.8 ± 0.8) × 104 cm−3 and 83.5 ± 57.9 μm3 cm−3, respectively. Days in three consecutive summers of 2004, 2005, and 2006 were classified as polluted days with PM10 over 150 μg m−3 and nonpolluted days with lower PM10. On nonpolluted days, particle number size distributions showed a maximum at about 60 nm with Aitken mode particles dominating number concentration. On polluted days, the contribution of accumulation mode particles increased, shifting the maximum of the number size distribution to over 80 nm. On polluted days with stagnant meteorological conditions, secondary aerosol dominated, with SO42−, NO3−, and NH4+ accounting for over 60% of accumulation mode particle mass. Particle number size distributions at both sites were similar. Number and volume concentrations of total particles at Yufa were 6% and 12% lower, respectively; those of accumulation mode particles were 2% and 15% lower. This means that air pollution in Beijing is mainly a regional problem. The regional accumulation mode particles are a metric for assessing the air quality since they influence most the visibility and total mass concentration. Their number and volume concentrations on polluted days were 5 × 103 cm−3 and 30 μm3 cm−3, respectively. Five new particle formation (NPF) events with continuous smooth growth were observed at both PKU and Yufa during CAREBeijing‐2006. These NPF events are regional or semiregional. Growth rates at PKU ranged from 1.2 to 5.6 nm h−1, and formation rates ranged from 1.1 to 22.4 cm−3 s−1. SO42−, NH4+, and oxalate might be important contributors to NPF events.
Tracheostomy tube capping is a commonly used test to determine if the tracheostomy tube can be removed. The success of the capping trial depends on the patient's ability to maintain sufficient ...spontaneous breathing with an occluded tracheostomy tube. The impact of an occluded tracheotomy tube on airway resistance is currently unknown. The aim of this study was to investigate tracheal pressure during capping or stoma button insertion and potential determinants concerning cuff.
Eight cuffed and uncuffed tracheostomy tubes and three stoma buttons of various manufacturers and sizes were inserted into the trachea model. Cuffs were completely deflated or contained atmospheric pressure. The trachea was ventilated bidirectional with a respirator in volume-controlled mode and volume flows 15-60 L/min. Tracheal pressure drop during inspiration as a parameter of pressure required to move gas through the airway was measured.
Tracheal pressure drops occurred linearly or irregularly during capping trials to a maximum of 4.2 kPa at flow rates of 60 L/min for atmospheric pressure cuffs. In tracheostomy tubes with completely deflated cuffs, pressure drop in the trachea reaches a maximum of 3.4 kPa at a flow rate of 60 L/min. For tracheostomy tubes with cuff smaller inner or outer diameters do not regularly result in lower tracheal pressure drop. The pressure drop varies between different tracheostomy tubes depending on the manufacturer. In cuffed tracheostomy tubes, we observed three phenomena: sail-like positioning, folding over, and tightening of the cuff during flow. The maximum tracheal pressure drop during stoma button insertion reaches 0.014 kPa.
The cuff is a central element for the pressure drop in the airway and thus airway resistance during spontaneous translaryngeal breathing with a capped TT. Complete deflation reduces the pressure drop in the trachea. Due to deformation of the cuff, measured pressures are irregular as the volume flow is increased. Incomplete deflated cuffs and material characteristics of tracheostomy tubes and cuffs in addition to anatomical and clinical variables may cause unsuccessful capping trials due to increased airway resistance. All stoma buttons showed that pressure drop and thus airway resistance due to stoma buttons has no clinical relevance.
The rigid tracheotomy endoscope (TED) was recently introduced to improve the fiberoptic technique during percutaneous dilatational tracheotomy (PDT) in critically ill patients. The aim was to ...evaluate the long-term complications of PDT using TED equipment in a prospective multicenter investigation.
One hundred eighty adult patients underwent PDT using TED in four German hospitals. Patients who were alive or their guardians were contacted via telephone and interviewed using a structured questionnaire 6 months following the tracheostomy procedure. Patients with airway complaints were invited for outpatient clinical ENT examination. The incidence of adverse events related to PDT was registered.
Of 180 patients who received tracheostomy, 137 (76.1%) were alive at the time of follow-up. None of the 43 lethal events was related to the PDT. Fifty-three (38.7%) patients were available for follow-up examination, whereas 14 (10.2%) were able to visit ENT physicians. Two (3.8%) out of 53 patients developed tracheocutaneous fistula with required surgical closure of tracheostoma. Dyspnea (7.5%), hoarseness (5.7%), stridor and swallowing difficulties (both with 3.8%) were the most common complaints. Tracheal stenosis was confirmed in 1 patient (1.88% 95% CI: 0.33; 9.93).
The use of TED for PDT in the clinical setting is safe regarding adverse events at 6-month follow-up. The incidence of tracheal stenosis after PDT with TED is comparable with that of flexible bronchoscopy; however, its role for PDT at the intensive care unit should be clarified in further investigations.
Air quality measurements usually consist of ground-based instrumentation at fixed locations. However, vertical profiles of pollutants are of interest for understanding processes, distribution, ...dilution and concentration. Therefore, a multicopter system has been developed to investigate the vertical distribution of the concentration of aerosol particles, black carbon, ozone, nitrogen oxides (NOx) and carbon monoxide and the meteorological parameters of temperature and humidity. This article presents the requirements by different users, the setup of the quadrocopter system, the instrumentation and the results of first applications. The vertical distribution of particulate matter next to a highway was strongly related to atmospheric stratification, with different concentrations below and above the temperature inversion present in the morning. After the qualification phase described in this article, two identically equipped multicopters will be used upwind and downwind of line or diffuse sources such as highways or urban areas to quantify the influence of their emissions on the local air quality.
Tracheotomy-Related Deaths Klemm, Eckart; Nowak, Andreas Karl
Deutsches Ärzteblatt international,
2017-Apr-21, 20170421, Letnik:
114, Številka:
16
Journal Article
Recenzirano
Odprti dostop
Tracheotomies are frequently performed on ventilated patients in intensive care and sometimes lead to fatal complications. In this article, we discuss the causes and frequency of death associated ...with open surgical tracheotomy (OST) and percutaneous dilatational tracheotomy (PDT) on the basis of a review of the pertinent literature.
We systematically searched the PubMed, EMBASE, and Cochrane Library databases and the Karlsruhe Virtual Catalog for publications (1990-2015) on tracheotomy-related deaths in adults, using the search terms "tracheotomy" and "tracheostomy." 39 relevant dissertations were included in the analysis as well.
109 publications were included. Of the 25 056 tracheotomies described, there were 16 827 PDTs and 7934 OSTs; for 295 tracheotomies, the technique used was not stated. 352 deaths were reported, including 113 in patients treated with PDT, 49 in those treated with OST, and 190 deaths related to a tracheotomy without specification of the method used. The frequency of death among patients with OST and those treated with PDT was similar: 0.62% for OST (95% confidence interval 0.47; 0.82) and 0.67% for PDT (0.56; 0.81). The most common causes of death and their frequencies, as a percentage of all tracheotomies, were hemorrhage (OST: 0.26% 0.17; 0.40, PDT: 0.26% 0.19; 0.35), loss of airway (OST: 0.21% 0.13; 0.34, PDT: 0.20% 0.14; 0.28), and false passage (OST: 0.11% 0.06; 0.22, PDT: 0.20% KI 0.15; 0.29).
Bias in the data cannot be excluded, as these were not epidemiologic data and the documentation was found to be incomplete. The likelihood of a fatal complication seems to be the same with both tracheotomy techniques as far as can be determined from the available evidence. Tracheotomy-related deaths can be avoided in several ways: by thorough training under the leadership of experienced physicians, by the use of the World Health Organization's Surgical Safety Checklist regardless of where the tracheotomy is performed, and by the continuous vigilance of nursing staff.
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