2014年 · 第37卷第11期

There has been such a controversy in the academic circles of respiratory and critical illness: is severe pneumonia combined with hypoxemia ARDS? Supporters believe that severe pneumonia with hypoxemia should be pulmonary ARDS, and it is the main cause of pulmonary ARDS; Opponents believe that severe pneumonia, especially bacterial pneumonia, often has no obvious damage to the alveolar structure although there are multiple lobar lesions. Even if some severe pneumonia causes damage to other lobes or segments due to inflammatory waterfall reaction secondary to focal pneumonia, the secondary lesions should belong to the characteristics of pulmonary exogenous ARDS. Therefore, many authoritative foreign literatures often write severe pneumonia and ARDS separately when describing acute hypoxic respiratory failure, indicating that there are indeed differences between them. Therefore, we need to seriously think and explore the similarities and differences between the two^[1,2]。

Increased blood lactate concentration is a common clinical phenomenon in critically ill patients. Hyperlactatemia can be used as an important indicator to judge the prognosis of patients, and can reflect early organ dysfunction in severe patients^[1,2]Therefore, blood lactate concentration has also become an important monitoring indicator for critically ill patients. However, recent systematic reviews suggest that blood lactate concentrations in critically ill patients do not specifically reflect their prognosis^[3]Such results seem to coincide with the background in which the concept of lactate clearance has been proposed in recent years. Lactic acid clearance is the body's ability to remove lactic acid over a specific period of time. Some studies have confirmed that lactate clearance rate is more specific to judge prognosis than blood lactate concentration monitoring, especially for the early stage of critically ill patients. For example, lactate clearance>36% in the first 6 h of sepsis is considered to be an indicator of good prognosis^[4,5]。 Guided therapy targeting lactate clearance is more meaningful for reducing 28-day mortality in sepsis patients^[6]。 How to understand the significance of hyperlactatemia in the diagnosis and treatment of critically ill patients needs to start with lactic acid itself.

The purpose of drug nebulization therapy is to deliver a therapeutic dose of drug to the targeted site. For patients with pulmonary lesions, aerosol administration can achieve higher local drug concentrations and reduce systemic adverse reactions compared with other modes of administration. In recent years, the continuous innovation and improvement of aerosol inhalation technology have improved the drug output and inhalation efficiency, and increased the drug concentration in the lungs. However, the results of the survey showed that 28% to 68% of patients did not use the pressure meter dose inhaler (pMDI) and dry power inhaler (DPI) correctly^[1], resulting in the ineffectiveness of the nebulization treatment. Different atomizers have different aerosol generation mechanisms, and each has its own advantages and disadvantages. Therefore, according to the performance characteristics of various nebulizers, appropriate patients, drugs, treatment time, administration route and dosage should be selected, and patients should be guided to use them correctly, so as to achieve the effect of nebulization therapy^[2,3]。

Suction of airway secretions means that the patient can't effectively eliminate sputum, blood, aspirated stomach contents and other foreign bodies in the airway due to reduced cough ability, and it needs to be eliminated under external suction to keep the airway unobstructed. The establishment of artificial airway leads to the loss of the original function of upper airway, especially the use of a large number of sedatives, which significantly reduces the cough ability of patients. Therefore, in patients with poor cough ability, especially in patients who have established artificial airways, the suction of airway secretions has become one of the conventional techniques that medical workers must master.

The establishment of artificial airways has changed the environment and mode of aerosol delivery. Aerosol is produced from the atomizing device, delivered through the pipeline and artificial airway under the positive pressure of the ventilator, and finally enters the lower respiratory tract. The whole process is affected by a series of complex factors^[1,2,3]。

Artificial airway is an effective means to ensure airway patency, and plays an extremely important role in the rescue process. However, the establishment of artificial airway will damage and destroy the normal physiological and anatomical functions of the body to a certain extent, which will bring harm to patients. After the establishment of artificial airway, especially after tracheal intubation, the patient's swallowing is limited, and oral secretions and gastroesophageal reflux are blocked by the balloon and retained above the balloon, which will form on-balloon retention. Studies at home and abroad have shown that airbag retention is an important source of ventilator associated pneumonia (VAP) pathogens^[1,2,3]。 Therefore, managing the air bag is one of the important means to reduce the occurrence of VAP.

Generally speaking, conventional positive pressure ventilation is still the main means of clinical treatment of various types of respiratory failure. With the progress of science and technology and the renewal of the concept of respiratory therapy, some new mechanical ventilation modes have emerged in clinical and scientific research, such as fluid ventilation, high frequency ventilation, neuromodulation assisted ventilation, prone position ventilation, proportional assisted ventilation and various combined ventilation modes, and some progress has been made^[1,2,3,4]。 However, for severe ARDS such as severe pneumonia, neonatal respiratory distress syndrome, pulmonary blast injury, severe inhalation injury, avian influenza and idiopathic pulmonary fibrosis, refractory hypoxemia and very low compliance, normal positive pressure ventilation and the above-mentioned new mechanical ventilation modes sometimes not only fail to maintain normal oxygenation, but also easily lead to complications such as oxygen poisoning and ventilator associated lung injury (VALI), which seriously affect the prognosis^[5]。 Therefore, it is particularly important to seek one or several combined ventilation modes to solve many problems such as oxygenation, carbon dioxide retention, oxygen poisoning and VALI.

The breathing movement is the rhythmic enlargement and contraction of the thorax caused by the contraction and relaxation of the respiratory muscles, thus achieving the purpose of inhaling oxygen and exhaling carbon dioxide. Inspiratory muscles mainly include diaphragm, external intercostal muscles and auxiliary inspiratory muscles, such as scalene muscle and sternocleidomastoid muscle. The diaphragm, as the primary inspiratory muscle, plays a 70% role in calming inspiration. Decreased diaphragm strength can cause shortness of breath and difficulty breathing, and even respiratory failure. Objective and valid evaluation of diaphragmatic function will be useful in diagnosing neuromuscular disorders to be consulted for dyspnea or respiratory failure. For patients with restrictive ventilatory dysfunction, type II respiratory failure and normal chest X-ray, respiratory muscle dysfunction should be highly suspected and diaphragm function test should be performed.

Maintaining sufficient humidification in the airway is a necessary physiological condition to maintain the normal clearance function of the mucociliary system on the airway surface and the normal characteristics of the alveolar epithelium. Under normal circumstances, the upper airway has a physiological humidification effect on the inhaled gas, so that the inhaled gas reaches 100% relative humidity when it reaches a horizontal position 4~5 cm below the tracheal carina, and the absolute humidity at this time is about 44 mg/L. This horizontal position is also called isothermal saturated interface ISB^[1]。 However, when inhaled dry gas or inhaled air flow bypasses the upper airway and directly enters the lower airway, especially in invasive and non-invasive mechanical ventilation, or spontaneous breathing and ventilation of patients with artificial airways, the isothermal saturation interface will be displaced in the direction of the lower airway, and poor humidification of the respiratory tract will easily occur, resulting in dry mucosa of the respiratory tract, reduced function of mucociliary system, thick retention of sputum, and affecting respiratory system function^[2]。 Therefore, it is very important to humidify the inhaled gas during invasive, non-invasive mechanical ventilation, or ventilation through artificial airways. The current status and research progress of airway humidification in the above clinical states are summarized as follows.

OSAHS is a disease mainly manifested by snoring, frequent apnea, hypoxia and daytime sleepiness caused by repeated upper airway collapse during sleep. Epidemiological investigations indicate that OSAHS is a common disease, affecting 4% of middle-aged men and 2% of middle-aged women^[1]。 OSAHS is closely related to hypertension, diabetes and cardiovascular and cerebrovascular diseases, and is an independent risk factor for hypertension and insulin resistance. Due to the high prevalence of OSAHS and its harm to health, scholars at home and abroad have conducted a lot of research on its etiology and pathogenesis, and found that OSAHS has obvious family aggregation, and is a complex polygenic hereditary disease. It was found that genetic genes related to obesity and related metabolic syndrome, craniofacial structural abnormalities, impaired ventilation regulation, sleep and circadian rhythm disorders, etc. are also involved in the pathogenic factors of OSAHS. Genetic susceptibility studies of OSAHS have also mainly focused on finding genes related to these factors, which are reviewed below.

myxofibrosarcoma (MFS) is a rare fibroblastic malignancy with varying degrees of myxoid stroma, pleomorphic, and distinctive curvilinear vessels^[1]。 The tumor occurs in the limbs, but the trunk, head and neck, chest and abdomen are relatively rare^[2]。 A case of chest wall MFS admitted to Shanghai Pulmonary Hospital affiliated to Tongji University is reported as follows.

3D printing technology is a hot topic in various fields at present, and has made significant progress in the medical field. The application of 3D printing technology in the medical field, especially in the respiratory field, is introduced as follows.

Transbronchial needle aspiration biopsy (TBNA) is an operation technique in which a special puncture needle with flexible catheter is entered into the airway through a bronchoscope, and penetrates the wall of the trachea to puncture and aspirate the trachea and extrabronchial lesions to obtain cells or tissue specimens^[1,2]。 Ultrasound bronchoscope (EBUS) is a device that installs an ultrasound probe at the front end of the bronchoscope. Combined with a special suction biopsy needle, it can be guided by real-time ultrasound to descend TBNA. The color energy Doppler of electronic convex array scanning can help confirm the position of blood vessels and prevent accidental penetration of blood vessels. The visibility and easy control of EBUS-TBNA make the technology spread rapidly^[3,4]The conventional TBNA is referred to as conventional TBNA (C-TBNA). C-TBNA technology uses markers in the airway cavity combined with imaging positioning for puncture. Because of its high requirements for the operator's anatomical positioning and three-dimensional thinking, it is called "blind puncture", resulting in mixed puncture results. Although some scholars believe that EBUS-TBNA should become the only alternative TBNA technology, it is undeniable that C-TBNA technology has the advantages of being simpler, easy to learn, simple in equipment, cheap in cost and can puncture nodular lesions around the lung. EBUS-TBNA is irreplaceable.

Acute respiratory distress syndrome (ARDS) is a diffuse alveolar injury induced by endogenous, exogenous or combined injury factors. ARDS is a clinically critical disease, with severe hypoxemia and respiratory distress as the main manifestations, and often requires mechanical ventilation support treatment. In recent years, with the deepening of the understanding of pathophysiology and respiratory physiology of ARDS, a variety of mechanical ventilation strategies for ARDS have been proposed on the basis of physiological research, and they have been verified in large-scale clinical studies, which provide theoretical and practical basis for improving the prognosis of ARDS patients.

The 4th event of the 2014 Beijing Young Respiratory Scholars Salon was held in the Chinese Medical Association on July 31, 2014. This salon activity aims to explore the thinking brought about by the 2014 Global Initiative on Chronic Obstructive Pulmonary Disease (GOLD) update, and is hosted by Dr. Jin Jianmin, Department of Respiratory Affairs, Beijing Tongren Hospital affiliated to Capital Medical University.

Levofloxacin and moxifloxacin are the two most common fluoroquinolones for the treatment of multidrug-resistant tuberculosis (MDR-TB), but there is a lack of studies on the effect of both in the treatment of MDR-TB. The aim of this study was to compare the therapeutic effects of levofloxacin and moxifloxacin on MDR-TB.

The "10th National Conference on Respiratory Infection and the 4th Sino-Japanese Symposium on SARS" jointly organized by the Editorial Board of Chinese Journal of Tuberculosis and Respiratory Medicine, the Infectious Disease Group of Respiratory Medicine Branch of Chinese Medical Association, the Professional Committee of Drug Clinical Evaluation of Chinese Pharmaceutical Association, Guizhou Provincial People's Hospital and Guizhou Provincial Medical Association was successfully held in Guiyang from June 20 to 22, 2014.

With great sadness, we deeply mourn Professor Ding Dongjie, an outstanding Communist Party member of the Communist Party of China, a famous respiratory expert, a good leader and doctor of Peking University People's Hospital, and a senior editorial member of Chinese Journal of Tuberculosis and Respiratory Medicine. Professor Ding Dongjie was formerly Vice President and Party Secretary of Peking University People's Hospital. Due to ineffective treatment, he unfortunately died at 16: 45 on September 27th, 2014 in Peking University People's Hospital at the age of 84.

Dear Editor Teacher: Hello!

Dear Dr. Mou Xiangdong: Hello!

Dear Dr. Mou Xiangdong: Hello!

Nebulization inhalation, airway secretion suction, and treatment of balloon retention after tracheal intubation are common operation techniques in respiratory and critical care medicine departments. However, problems such as irregular operation and unsatisfactory treatment effect often occur in clinical work. Therefore, the Respiratory Therapy Group of Respiratory Disease Branch of Chinese Medical Association has formulated the "Expert Consensus on Atomization Therapy (Draft)", "Expert Consensus on Attraction of Adult Airway Secretions (Draft)", "Expert Consensus on Atomization Inhalation during Mechanical Ventilation (Draft)" and "Expert Consensus on Management of Artificial Airway Balloons (Draft)" respectively. According to the Delphi grading standard proposed by the International Forum on Infection (ISF) in 2001, the recommendations are divided into five levels according to the research methods and results, and the recommendations are divided into A ~ E levels according to Delphi grading. This is the first guiding literature formulated on four clinical routine operation techniques based on the principles of evidence-based medicine in China, which is worth reading. Especially today, when smog rages, it is even more precious!