Clinical assessment of awake endotracheal intubation using the lightwand technique alone in patients with difficult airways

Background There is few study to determine whether the use of the lightwand technique alone could achieve effective, safe and successful awake endotracheal intubation （ETI）, therefore we designed a prospective clinical study to systematically evaluate the feasibility, safety and efficacy of awake ETI using the lightwand alone in patients with difficult airways.
Methods Seventy adult patients with difficult airways were enrolled in this study. After the desired sedation with fentanyl and midazolam, airway topical anesthesia was performed with 9 ml of 2% lidocaine, which were in order sprayed in three aliquots at 5 minutes intervals into the supraglottic （two doses） and laryngotracheal areas （one dose） using a combined unit of the lightwand and MADgic atomizer. After airway topical anesthesia, awake ETI was performed using a Lightwand. Subjective assessments by patients and operators using the visual analogue scores （VAS）, and objective assessments by an independent investigator using patients＇ tolerance and reaction scores, coughing severity, intubating conditions and cardiovascular variables were taken as the observed parameters.
Results Of 210 airway sprays, 197 （93.8%） were successfully completed on the first attempt. The total time for airway spray was （14.6±1.5） minutes. During airway topical anesthesia, the average patients＇ tolerance scores were 1.7-2.3. After airway topical anesthesia, the mean VAS for discomfort levels that the patients reported was 6.5. Also airway topical anesthesia procedure was rated as acceptable and no discomfort by 94.3% of patients. The lightwand-guided awake ETI was successfully completed on first attempt within 29 seconds in all patients. During awake ETI, patients＇ reaction and coughing scores were 1.9 and 1.6, respectively. All patients exhibited excellent or acceptable intubating conditions. Cardiovascular monitoring revealed that changes of systolic blood pressure and heart rate at each stage of airway manipulations were less than 20% of baseline values. The postoperative follow-up showed that 95.7% of patients had no recall or slight memories of all airway instrumentation. The incidence of postoperative mild airway complications was 38.6%.
Conclusion Alone use of the lightwand technique can achieve effective, safe and successful awake ETI in patients with difficult airways.     

Fluid flow in distensible vessels

1. Flow in single vascular conduits is reviewed, divided into distended and deflated vessels. 2. In distended vessels with pulsatile flow, wave propagation and reflection dominate the spatial and temporal distribution of pressure, determining the shape, size and relative timing of measured pressure waveforms, as well as the instantaneous pressure gradient everywhere. Considerable research has been devoted to accessing the information on pathological vascular malformations contained in reflected waves. Slow waves of contraction of vessel wall muscle, responsible for transport of oesophageal, ureteral and gut contents, have also been modelled. 3. The pressure gradient in a vessel drives the flow. Flow rate can be predicted both analytically and numerically, but analytical theory is limited to idealized geometry. The complex geometry of biological system conduits necessitates computation instead. Initially limited to rigid boundaries, numerical methods now include fluid-structure interaction and can simultaneously model solute transport, thus predicting accurately the environment of the mechanosensors and chemosensors at vessel surfaces. 4. Deflated vessels display all phenomena found in distended vessels, but have additional unique behaviours, especially flow rate limitation and flow-induced oscillation. Flow rate limitation is widespread in the human body and has particular diagnostic importance in respiratory investigation. Because of their liquid lining, the pulmonary airways are also characterized by important two-phase flows, where surface tension phenomena create flows and determine the patency and state of collapse of conduits. 5. Apart from the vital example of phonation, sustained self-excited oscillation is largely avoided in the human body. Where it occurs in snoring, it is implicated in the pathological condition of sleep apnoea.     

Nilotinib: a novel Bcr-Abl tyrosine kinase inhibitor for the treatment of leukemias

COPD is a syndrome characterised by progressive airflow limitation caused by chronic inflammation of the airways and lung parenchyma. It is the most common lung disease, carrying a significant mortality, morbidity and healthcare costs worldwide. COPD is associated with increased activity of parasympathetic nervous system that plays a dominant role in the regulation of airways tone. As cholinergic tone seems to be the only reversible component of COPD, muscarinic receptor antagonists (MRAs) represent the most effective class of bronchodilators in COPD. Thus MRAs remain the mainstay of pharmacotherapy in COPD as they increase expiratory flow rate by decreasing airway smooth muscle tone and mucus secretion leading to enhanced lung function. The discovery of the different muscarinic receptor subtypes that are involved in the regulation of airway function led to the development of more subtype-selective MRAs for the treatment of COPD. Furthermore, it has been hypothesised that the compounds preferentially antagonise the muscarinic M3 receptor-mediated effects would provide better clinical efficacy with a reduction in adverse events related to the blockade of other muscarinic receptor subtypes. Based on this hypothesis, the present multi-centre, randomised, placebo-controlled study assessed the effectiveness of selective muscarinic receptor (M3) antagonist through oral delivery in COPD patients.     

The role of dispersion in particle deposition in human airways.

Aerosol dispersion and deposition are processes that occur concurrently in human airways. However, dispersion has not been properly accounted for in most deposition models. In this paper we have incorporated the latest understanding of dispersion into a dosimetry model and study the influence of dispersion on particle deposition in the lung. We show that dispersion influences the total deposition of inhaled particles and in particular increases the pulmonary deposition of fine mode particles. We also discuss how dispersion can help elucidate a number of clinical and epidemiologic results associated with particle deposition in the lung.     

Treating allergic rhinitis and asthma: different sides of the same fence

Allergic asthma and rhinitis are highly prevalent diseases. Although they are diagnosed and treated separately, many patients suffer from both. There is data suggesting that they can be considered as manifestations of the same disease or syndrome, but in different locations. This article discusses the evidence favouring a joint clinical approach, and the main therapeutic tactics to achieve disease control; tries to establish the importance of isolated and adjuvant treatment of rhinitis and asthma, highlighting a small number of clinical studies regarding the subject; and indicates points for future research.     

一种用于上呼吸道的光纤压力传感器的设计

主要论述一种用于生物医学领域的光纤变送器的设计方法。这种光纤用于上呼吸道部分或全部闭塞而引起睡眠紊乱患者。     

IMPEDANCE MEASUREMENT DURING AIR AND HELIUM-OXYGEN BREATHING BEFORE AND AFTER SALBUTAMOL IN COPD PATIENTS

1. The forced oscillation technique is an effort-independent method used to characterize the mechanical impedance of the respiratory system. To support the hypothesis that non-invasive partitioning of total pulmonary resistance is possible by this technique, impedance was measured during air breathing and after equilibration with a mixture of 80% helium (He) and 20% oxygen (O2) in 21 chronic obstructive pulmonary disease (COPD) patients by means of a forced pseudo-random noise pressure signal over a frequency spectrum from 4 to 52 Hz. Furthermore, during inhalation of both gas mixtures impedance was determined before and after inhalation of 0.400 mg Salbutamol. 2. He + O2 breathing caused less negative frequency dependence of resistance and a significant decrease in reactance over the range 16-52 Hz. Inhalation of Salbutamol caused a marked increase in reactance values over the range 8-40 Hz. However after equilibration with the He + O2 mixture, Salbutamol caused a significant decrease in resistance and a significant increase in reactance at all frequencies. 3. The results during He + O2 breathing are in accordance with a partitioning of airways resistance into central and peripheral components. The decrease in reactance during He + O2 can be explained by a density dependent decrease in inductive reactance. By comparing the impedance data during air and He + O2 breathing, it can be concluded that a distribution of pulmonary resistance with minimal losses in the larger airways is more sensitive for detecting changes in the peripheral airways in COPD patients.     

The mouse trap

Mouse models of asthma are now being used extensively in drug research. However, the successful unravelling of combinatorial interplays of cells and molecules in the murine airways may not be matched by equally successful demonstrations of an asthma-like pathophysiology. Here, Carl Persson, Jonas Erjefält, Magnus Korsgren and Frank Sundler discuss the fact that major features of asthma may still need to be demonstrated in the airways of allergic mice.     

Heterogeneity in epithelium-dependent responses

The airway epithelium exerts a profound influence on the responsiveness of bronchial smooth muscle to both contracting and relaxing agents. This may be due to the release of an epithelium-derived factor or factors. There is a considerable heterogeneity in the effects of the epithelium between orders of bronchi, between species, and between pharmacologic agents. Such heterogeneity may reflect variations in the release and/or effect of the epithelium-derived relaxing factor(s). This report demonstrates that: (1) there is a basal and a stimulated release of the factor, (2) the prominence of different types of release varies between species, (3) the effect of the epithelium on relaxation of bronchial smooth muscle is greatest in the presence of high degrees of cholinergic tone, (4) the effects of the epithelium are not mediated via cyclic GMP, and (5) the epithelium-derived relaxing factor is not nitric oxide.