Ultrasonic Levitation for Airway Humidification.

This study employs the transmitter part of an ultrasonic proximity sensor to generate a powerful ultrasonic field for medical humidification. This field is created using an arrangement of small ultrasonic transmitter transducers configured in an acoustic levitator-style setup. As droplets pass through this ultrasonic field, they undergo disintegration, leading to an accelerated evaporation process. The research findings highlight a significant change in droplet size distribution due to ultrasonics, resulting in a notable increase in the rate of evaporation. As a result, this study presents a conceptual framework for reimagining humidification devices for lung therapeutic purposes through the utilization of simple sensor technology.

Application of the integrated airway humidification device enhances the humidification effect of the rabbit tracheotomy model.

Long-term mechanical ventilation after tracheotomy is a common treatment in intensive care unit patients. This study investigated the differences among the effects of different wetting states on the airway, lung, and serum inflammatory factors. New Zealand rabbits (n = 36) were selected to construct tracheotomy models and then divided into four groups: Model, Mask, YTH, and Sham groups. Lung tissue dry/wet ratio was used to evaluate the humidification effect; cytokines, including tumor necrosis factor-α, interleukin (IL)-6, IL-8, and IL-10, were used to evaluate the inflammatory response; hematoxylin and eosin staining was used to evaluate the histopathology. Post hoc analysis based on the Dunnett t-test was applied. A self-developed integrated wetting device could increase the utilization of wetting solution, enhance the effect of wetting to protect tissue integrity, and suppress airway inflammation, reducing the expression of pro-inflammatory factors while promoting the expression of anti-inflammatory factor IL-10 to inhibit the inflammatory response, compared to other methods. The integrated humidification device provided a new method for clinical nursing practice, improving clinical efficiency and reducing nursing workload. Further clinical trials are required to test its effectiveness and safety in the clinic.

Assessment of high-flow nasal cannula efficacy in humidification of infant airways: A computational fluid dynamics approach.

INTRODUCTION: High-flow nasal cannula therapy has garnered significant interest for managing pathologies affecting infants' airways, particularly for humidifying areas inaccessible to local treatments. This therapy promotes mucosal healing during the postoperative period. However, further data are needed to optimize the use of these devices. In vivo measurement of pediatric airway humidification presents a challenge; thus, this study aimed to investigate the airflow dynamics and humidification effects of high-flow nasal cannulas on an infant's airway using computational fluid dynamics. METHODS: Two detailed models of an infant's upper airway were reconstructed from CT scans, with high-flow nasal cannula devices inserted at the nasal inlets. The airflow was analyzed, and wall humidification was modeled using a film-fluid approach. RESULTS: Air velocities and pressure were very high at the airway inlet but decreased rapidly towards the nasopharynx. Maximum relative humidity-close to 100%-was achieved in the nasopharynx. Fluid film development along the airway was heterogeneous, with condensation primarily occurring in the nasal vestibule and larynx. CONCLUSION: This study provides comprehensive models of airway humidification, which pave the way for future studies to assess the impact of surgical interventions on humidification and drug deposition directly at operative sites, such as the nasopharynx or larynx, in infants.

Continuous humidification enhances postoperative recovery in laryngeal cancer patients undergoing tracheotomy.

OBJECTIVE: To investigate the effects of perioperative continuous humidification on patients with laryngeal cancer undergoing tracheotomy. METHODS: Eighty patients with laryngeal cancer underwent tracheotomy in our hospital were selected as the subjects and divided into the observation group and the control group according to random table method. Patients in the control group were given routine tracheotomy care, including regular open endotracheal suction, tracheotomy nursing, oral care, dietary intervention, etc., while those in the observation group were given continuous airway humidification on the basis of the control group. The differences in sputum pH, viscosity, comfort, cough frequency, and respiratory ventilation were compared between the two groups at three postoperative time points. The incidence of complications such as pulmonary infection, bloody sputum and sputum crust, and the improvement of clinical symptoms were compared between the two groups. RESULTS: The sputum pH of patients in the observation group was higher than that in the control group at the 4th and 7th postoperative days (P<0.001). The observation group showed significantly lower percentage of grade 3 viscous sputum and higher comfort scores than the control group at the 7th postoperative day (P=0.020, P<0.001). The observation group showed lower cough frequency and higher airway patency than the control group at the 4th and 7th postoperative days (P<0.001, P<0.001, P<0.001, P=0.007). CONCLUSION: Perioperative continuous airway humidification in patients with laryngeal cancer undergoing tracheotomy could reduce sputum consistency and cough frequency, improve comfort and respiratory patency of patients, and has positive significance in accelerating their postoperative rehabilitation.

A comparative evaluation of three common airway humidification methods for patients with severe traumatic brain injury.

BACKGROUND: Airway humidification methods are commonly used in clinical practice, but no clear consensus exists on which particular method is best suited for specific clinical conditions. METHODS: In this retrospective study, we carried out a quantitative evaluation of three methods commonly used for patients with severe traumatic brain injury (STBI). We recruited 150 patients who received airway humidification after tracheotomy. Subjects were divided into three groups according to the humidification method they received which included oxygen atomizer (OA) group, heat and moisture exchangers (HMEs) group, and heated humidifiers (HHs) group. Variables including phlegm viscosity, humidification effects, phlegm formation rates, daily sputum inhalation times, airway spasm, secondary lung infections, daily nursing load, and evaluation of nurse job satisfaction levels were documented. RESULTS: Results indicated that the OA tended to cause either insufficient or excessive humidification, whereas phlegm scab formation was significantly reduced in HHs. HMEs and HHs displayed equal humidification effects, and a similar daily sputum induction and consequent nursing load. Airway spasm was a frequent occurrence in OA. The severity, but not the infection ratio, of secondary infection decreased significantly in HHs by the 30th day. The OA significantly reduced nursing load, but demonstrated the worst humidification effects. CONCLUSIONS: Overall results suggested that the HHs is more suitable for airway nursing of STBI patients who are bedridden for extended periods.

Expert consensus on artificial airway humidification care in adult critical patients / 现代临床护理

Objective To develop an expert consensus on artificial airway humidification care in critical adult patients(refer as"Consensus"hereafter)for a standardised procedure of artificial airway humidification.Methods Reviews of domestic and international literatures relevant to artificial airway humidification care in critical adult patients were conducted.Clinical experiences of medical and nursing experts were taken into consideration.Two rounds of expert consultations were conducted to finalise the Consensus.Results Various aspects were studied including concepts,targeted range of temperature and humidification,methods of humidification,selection of humidification liquid and methods for evaluation of humidification effectiveness.The Consensus was applicable to the management of humidification of artificial airway in critical adult patients.Conclusions The Consensus exhibits a certain level of scientific rigor and practical applicability.It serves as a theoretical basis and practical guide to clinical nursing personnel in the management of artificial airway humidification.

Airway humidification therapy for pertussis in infants / 中国基层医药

Objective:To investigate the effects of airway humidification therapy on pertussis in infants.Methods:Sixty children with pertussis who received treatment in Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine from May 2020 to September 2021 were included in this study. They were randomly divided into study and control groups, with 30 infants per group. The control group was treated with conventional drugs. The study group was subjected to airway humidification therapy based on conventional drug treatment. Clinical efficacy was evaluated in each group. Time to an improvement in clinical symptoms and length of hospital stay were recorded. Lung function indicators and serum inflammatory factor levels were determined before and after treatment. Pertussis-related complications were recorded.Results:The overall response rate in the study group was significantly higher than that in the control group (100.00% vs. 76.7%, χ2 = 5.82, P = 0.016). Time to disappearance of spastic cough, time to resolution of cyanosis, time to disappearance of pulmonary rales, and length of hospital stay in the study group were (3.10 ± 0.67) days, (1.53 ± 0.68) days, (4.27 ± 0.58) days, and (11.57 ± 0.73) days, respectively, which were significantly shorter than (4.23 ± 1.99) days, (2.67 ± 1.77) days, (5.63 ± 2.38) days, (13.33 ± 2.40) days ( t = 2.93, 3.27, 3.04, 3.86; P = 0.005, 0.002, 0.003, P < 0.001). Respiratory rate in the study group was significantly lower than that in the control group [(21.83 ± 1.15) breaths/minute vs. (24.23 ± 3.12) breaths/minute, t = 3.94, P = 0.002]. Tidal volume/kg body weight, the ratio of time to peak expiratory flow to total expiratory time and the ratio of volume to peak expiratory flow to total expiratory volume in the study group were (10.70 ± 0.81) mL/kg, (41.60 ± 1.57)%, (42.89 ± 1.44)%, respectively, which were significantly higher than (9.78 ± 1.34) mL/kg, (39.18 ± 3.37)%, (40.20 ± 3.05)% in the control group ( t = 3.21, 3.56, 4.36; P < 0.001, P = 0.001, P < 0.001). Serum tumor necrosis alpha (TNF-α), interleukin-6 and interleukin-8 levels in the study group were (62.44 ± 2.96) ng/L, (46.59 ± 1.96) ng/L, (54.63 ± 3.27) ng/L, respectively, which were significantly lower than (79.86 ± 3.30) ng/L, (58.20 ± 2.10) ng/L, (63.31 ± 3.86) ng/L in the control group ( t =21.53, 22.13, 9.38, all P < 0.001). The overall incidence of pertussis in the study group was significantly lower than that in the control group (3.3% vs. 26.7%, χ2 = 4.71, P = 0.030). Conclusion:Airway humidification therapy can shorten the time to reduction of symptoms of spasmodic pertussis, improve clinical efficacy, strengthen pulmonary ventilation function, lower respiratory tract inflammatory responses and reduce the risk of pertussis-related complications.

Study on the effects of different humidifying liquids applied to non-invasive mechanical ventilation airway humidification / 药学实践杂志

Objective To study the effects of different airway humidification fluid applied to non-invasive mechanical ventilation.Methods 121cases of non-invasive mechanical ventilation admitted to the hospital from May 2016to May 2017were randomly divided into three groups.40cases in group A received sterile water for injection as humidifying liquid.40cases in group B received normal saline and 41cases in group C received 1.25％sodium bicarbonate water solution.The viscosity of sputum and the comfort of humidification for the three groups were compared.Results On day 1, there was no significant difference in the sputum viscosity among the three groups. (F=0.230, P=0.795).On day 2, group A had the highest sputum viscosity, followed by group B and group C.The difference was statistically significant (F=4.416, P＜0.05).The same results were obtained on day 3with statistically significant difference (F=11.388, P＜0.001).Group C had the highest comfort score among the three groups with statistically significant difference (F=37.901, P＜0.001).Conclusion 1.25％sodium bicarbonate water solution makes sputum more diluted and gives patients with better comfort.It can be considered as the fluid of choice for patients with high sputum amount.

Network meta-analysis of airway humidification in patients with non-mechanical ventilation after domestic gastrectomy / 中国实用护理杂志

Objective@#To evaluate the therapeutic effects of various airway humidification methods to prevent pulmonary infection in non-mechanical ventilation patients by network meta-analysis.@*Methods@#The Pubmed, Embase, Web of Science, Wanfang data, and CNKI databases were searched and a randomized controlled trial (RCT) was developed for the method of humidification in non-mechanical ventilation patients after domestic air-surgery. The staff independently screened the literature, extracted the data, and used the stata14.0 software for network meta-analysis.@*Results@#In the 3 342 articles, 25 of them were included in the Meta-analysis, involving 6 methods of airway humidification. The order of effectiveness: first place in artificial nose, second in venturi humidification device, third in continuous atomization, Intermittent atomization ranked fourth, continued to drop into the fifth place, intermittently dropped into the sixth position of humidification.@*Conclusion@#The effectiveness of artificial nose device and venturi humidification device has been gradually recognized by domestic counterparts. Meta analysis shows that it is effective in preventing lung infection and worth promoting.

Airway humidification therapy / 中华实用儿科临床杂志

Airway humidification is one of the important measures for airway management.To master the hu-midification indication,humidification method and effect evaluation is helpful to achieve the best humidification effect, reduce complications,reduce incidence of pulmonary infection and promote early recovery of children.

The best practice strategy of humidification oxygen therapy for patients with artificial airway during weaning from ventilation / 中国实用护理杂志

Objective To explore the better humidification oxygen therapy for patients with artificial airway from weaning to extubation, ensure the best humidification effect, keep airway unobstructed,shorten tubulization time and reduce the incidence of infection. Methods A total of 133 patients with artificial airway during weaning from ventilation admitted from March to December in 2016 in intensive care unit of the Second Affiliated Hospital of Chongqing Medical University were included in the study.They were divided into the experimental group(69 patients)and the control group(64 patients) by random lottery form.The experimental group was given improved combination device(venturi,heated humidifier and ventilator tube)during oxygen therapy for humidification and heating, while the control group was treated with oxygen therapy in endotracheal tube and continuous wet micro-injection pump 0.45% sodium chloride method.The heart rate,respiratory rate,blood oxygen saturation,offline time with tube,offline failure rate,sputum viscosity,sputum scab formation,irritant cough and pulmonary infection were compared between the two groups. Results The heart rate,respiratory rate,blood oxygen saturation and offline time with tube in the experimental group were(80.50±7.07)times/min,(17.38±1.92)times/min, 0.98±0.01,and(1.58±1.06)days,and which were(88.50±3.07)times/min,(21.38±1.51)times/min,0.96± 0.01 and(3.00±1.09)days in the control group.The differences were statistically significant(t=2.268-4.782,P<0.05 or 0.01).The offline failure(2 cases),sputum scab formation(3 cases),irritant cough(4 cases) and pulmonary infection(4 cases) were less than 8 cases, 12 cases, 20 cases,12 cases in control group. The differences were statistically significant (χ2=4.652-14.545, P < 0.05 or 0.01). The sputum viscosity ofⅠ,ⅡandⅢwere 5 cases,52 cases and 12 cases in the experimental group,which were better than 13 cases,11 cases and 40 cases in the control group.The difference was statistically significant(Z=3.385, P < 0.01). Conclusions The improved oxygen therapy heated humidify strategy can not only achieve satisfactory humidification effect, but also improve the success rate of offline machines, shorten tubulization time,promote the comfort and tolerance of patients,and reduce the occurrence of infection.

Design and application of new type of humidification fluid dropping joint for breathing machine / 医疗卫生装备

Objective To develop a humidification fluid dropping joint for the breathing machine to solve the problems in humidification fluid retension,pipeline leakage,pipeline fixation and etc.Methods A Infusion extension tube was involved in with 10 cm length left at the injector end.A hole was made at the side wall of the L-shaped joint of the breathing machine,whose internal diameter equaled to the external diameter of the extension tube.The extension tube was put into the joint through the hole,and the depth of imbedded tube was within 4 and 6 cm.Sealing and fixation at the connection between the tube and hole were executed with 502 glue and short tourniquet.Results The humidification fluid dropping joint could be connected with infusion apparatus of the pump or the infusion extension tube of the micro pump,which behaved well in eliminating accumulated humidification fluid,sputum suction,humidification and facilitating mechanical ventilation.Conclusion The joint developed gains advantages in easy manufacture,reducing complications and increasing the dependence on artificial airway,and thus is worthy promoting clinically.

Effects of two different methods for airway humidification for patients with tracheostomy：a Meta-analysis / 中华危重病急救医学

Objective To evaluate the effects of two different kinds of airway humidification for tracheostomy patients, and to provide their relevant clinical effect and suggestions for their use. Methods Online databases, including PubMed, EMBASE, JBI evidence-based nursing center library, the Cochrane Library, and Chinese databases (CNKI, Wanfang database, VIP, CBM) were searched systematically up to March 2015. Randomized controlled trials (RCTs) were considered eligible for inclusion if the following criteria were met: no history of respiratory tract infection; satisfactory nutritional status; tracheotomy performed; 18 years older. Two different humidification methods were used. Continuous airway humidification was used in the experiment group, while intermittent airway humidification was used in the control group. Two qualified reviewers reviewed the original articles, evaluating the quality of articles, and data were extracted independently. The enrolled RCTs were analyzed by Meta-analysis. Results A total of nine RCTs were included, containing 631 cases, among them 316 cases in expertment group, and 315 cases in control group. Continuous airway humidification was shown to be able to reduce the incidence of irritable cough [odds ratio (OR) = 0.20, 95% confidence interval (95%CI) = 0.12-0.34, P < 0.000 01], bleeding form mucosa of respiratory tract (OR = 0.25, 95%CI = 0.14-0.45, P < 0.000 01), sputum conglomeration (OR = 0.19, 95%CI = 0.10-0.39, P < 0.000 01), and pneumonia (OR = 0.29, 95%CI = 0.19-0.45, P < 0.000 01). The funnel plots were largely symmetrical, suggesting there was no publication bias in the Meta-analysis of two methods for airway humidification for tracheostomy patients. Conclusion Because the number of including articles was relative small, and the quality of some articles was poor, it is impossible to draw a reliable conclusion that continuous airway humidification could lower the incidence of complications for patients undergone tracheostomy.

Effect of accurate airway humidiifcation in patients with low-temperature plasma coblation-assisted tonsillectomy / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo investigate the effect of accurate airway humidification on hemorrhage, pharyngalgia, mucosal edema and sputum viscosity in patients with low-temperature plasma coblation-assisted tonsillectomy.METHODS58 cases were divided into three groups by using random numbers.In accurate airway humidification group, atomizing inhalation was carried out by AIRVOTM series apparatus; in oxygen atomizing group, budesonide suspension was used; in control group, saline was used. We evaluated the hemorrhage, pharyngalgia, mucosal edema and sputum viscosity in 3 consecutive postoperative days.RESULTSPharyngalgia in accurate airway humidification group and in oxygen atomizing group were both significantly reduced than that of the control group (P<0.001). Besides, in accurate airway humidification group, mucosal edema and sputum viscosity were significantly improved than that of the oxygen atomizing group (P<0.05) and control group (P<0.05).CONCLUSIONAccurate airway humidification could reduce the complications such as pharyngalgia, mucosal edema and purulent sputum after low-temperature plasma coblation-assisted tonsillectomy, and could accelerate recovery from surgery.

Effect research of two kinds of airway humidification solution for patients with tracheotomy of airway humidification / 中国实用护理杂志

Objective To compare the influence of tracheotomy after two wet fluid on airway and provide the basis for clinical treatment and care. Methods A total of 30 patients with severe brain injury stay neurosurgery tracheotomy were divided into 0.45% sodium chloride group and ambroxol hydrochloride group with 15 cases each by random digits table method, two airway humidification liquid (0.45%sodium chloride,0.9% sodium chloride + ambroxol hydrochloride) were each instilled in the trachea inner sleeve. Blood gas analysis was performed and the levels of serum lung surface active substances related protein-A (SP-A protein), interleukin-6, interleukin-8, tumor necrosis factor-alpha(TNF-α) were measured by enzyme linked immunosorbent assay (ELISA) before 1 d and after 3,7,14 d of tracheotomy. Results There were significant differences in arterial blood oxygen partial pressure, arterial carbon dioxide partial pressure, oxygenation index after 14 d of tracheotomy between ambroxol hydrochloride group and 0.45% sodium chloride group:(110.72±26.75) mmHg(1 mmHg=0.133 kPa) vs.(89.39±21.98) mmHg, (30.44±6.75) mmHg vs. (35.12±7.28) mmHg, 333.23±80.56 vs. 270.93±77.21, t=29.49,-8.63,7.44, P<0.01.There were significant differences in the levels of serum SP-A protein, interleukin -6, interleukin -8, TNF-α after 14 d of tracheotomy between ambroxol hydrochloride group and 0.45% sodium chloride group:(191.34 ±1.21) ng/L vs. (61.92 ±12.0) ng/L, (2.62 ±0.23) ng/L vs. (5.42 ±0.16) ng/L, (124.56 ±2.10) ng/L vs. (185.91 ±1.48) ng/L, (31.32±1.38) ng/L vs.(69.13±1.16) ng/L, t=75.72,-13.51,-23.89,-20.97, P<0.01. Conclusions The airway humidification effect of ambroxol hydrochloride group is better than 0.45%sodium chloride group, it can improve the wetting effect, and better protect the lung tissue, reduce the incidence of lung infection, make it an ideal airway humidification liquid.

Different methods of airway moist on wetting effect and pulmonary infection after tracheotomy for elderly patients with cerebral hemorrhage / 现代临床护理

Objective To compare the effects of airway humidification by intermittent atomization inhalation and micro pump control on pulmonary infection after tracheotomy in elderly patients with serebral hemorrhage. Methods From February 2012 to February 2013, 46 elderly patients with heavy craniocerebral injury and tracheotomy were set as the control group, treated with intermittent atomization inhalation. From March 2013 to March 2014, 50 elderly patients with severe craniocerebral injury and tracheotomy were set as the observation group, treated with micro pump controlled continuous airway humidification. The two groups were compared in terms of the satisfaction rate and incidence of pulmonary infection. Result The satisfaction rate of the observation group was higher than that of the control group and the incidence of pulmonary infection was significantly lower than that of the control group (P<0.05). Conclusion Micro pump controlled airway humidification for elderly patients with severe craniocerebral injury can improve the airway humidification effect and reduce the incidence of pulmonary infection.

The effect of respiratory mechanics in airway humidification with ambroxol during mechanical ventilation / 中国医师进修杂志

Objective To observe effect of using ambroxol to humidify of airway during mechanical ventilation to treat severe pneumonia in infants,and to explore dynamic changes of respiratory mechanics.Methods Sixty-five infants with severe pneumonia need ventilator treatment according the diagnosis criterion were divided into 2 groups by random digits table method:experimental group (33 cases) and control group (32 cases).Experimental group was used ambroxol and control group was used 0.9％ sodium chloride,each 2 ml intratracheal instillation,and then took the balloon pressurized oxygen 30 s,followed by ventilator,after 24 h.Changes of respiratory mechanics indexes were observed before and after treatment,including:mean airway resistance,lung dynamic compliance,work of breathing,airway plateau pressure.Respiratory mechanics values were recorded before and after treatment.Results After treatment for 24 h,the index in experimental group were better than those in control group.Mean airway resistance were (0.68 ± 0.04) cmH2O/ (L·s) and (0.57 ± 0.05) cmH2O/ (L·s),1 cmH2O =0.098 kPa,lung dynamic compliance were (3.17 ± 0.81) ml/kPa and (2.56 ± 0.69) ml/kPa,work of breathing were (0.54 ± 0.08) J/L and(0.41 ± 0.06) J/L,airway plateau pressure were (2.23 ± 0.58) cmH2O and (2.12 ± 0.63) cmH2O.There were significant differences (P ＜ 0.05).The mechanical ventilation time in experimental group was significantly shorter than that in control group [(64.08 ± 13.92) h vs.(79.57 ± 19.64) h] (P ＜0.05).Conclusion Airway humidification using ambroxol can better treat severe pneumonia,reduce airway resistance and improve alveolar ventilation,shorten time on the machine.

Effect of airway humidification on lung injury induced by mechanical ventilation / 中华危重病急救医学

Objective To explore the effect of airway humidification on lung injury as a result of mechanical ventilation with different tidal volume(VT). Methods Twenty-four male Japanese white rabbits were randomly divided into four groups:low VT with airway humidification group,high VT with airway humidification group,low VT and high VT group without humidification,with 6 rabbits in each group. Mechanical ventilation was started after intubation and lasted for 6 hours. Low VT denoted 8 mL/kg,while high VT was 16 mL/kg,fraction of inspired oxygen (FiO2)denoted 0.40,positive end-expiratory pressure(PEEP)was 0. Temperature at Y piece of circuit in airway humidification groups was monitored and controlled at 40℃. Arterial blood gas analysis,including pH value,arterial partial pressure of oxygen(PaO2),arterial partial pressure of carbon dioxide(PaCO2),lung mechanics indexes, including peak airway pressure(Ppeak)and airway resistance(Raw),and lung compliance was measured at 0,2,4, 6 hours of mechanical ventilation. The levels of tumor necrosis factor-α(TNF-α)and interleukin-8(IL-8)in plasma and bronchoalveolar lavage fluid(BALF)were determined by enzyme linked immunosorbent assay(ELISA). The animals were sacrificed at the end of mechanical ventilation. The wet to dry(W/D)ratio of lung tissues was calculated. Histopathologic changes in the lung tissueies were observed with microscope,and lung injury score was calculated. Scanning and transmission electron microscopies were used to examine the integrity of the airway cilia and the tracheal epithelium. Results Compared with low VT group,pH value in high VT group was significantly increased,PaCO2 was significantly lowered,and no difference in PaO2 was found. Ppeak,Raw,and lung compliance were significantly increased during mechanical ventilation. There were no significant differences in blood gas analysis and lung mechanics indexes between low VT with airway humidification group and low VT group. Compared with high VT group,PaCO2 in high VT with airway humidification group was significantly decreased,Ppeak raised obviously,and no difference in pH value,PaO2,Raw and pulmonary compliance was found. Compared with low VT with airway humidification group,no difference in blood gas analysis(PaCO2,mmHg,1 mmHg=0.133 kPa)was found,but Ppeak(cmH2O,1 cmH2O=0.098 kPa),Raw(cmH2O),and lung compliance(mL/cmH2O)were increased significantly in high VT with airway humidification group(PaCO2 at 2 hours:27.96±4.64 vs. 36.08±2.11,4 hours:28.62±2.93 vs. 34.55±5.50, 6 hours:29.33±2.14 vs. 35.01±5.53;Ppeak at 0 hour:14.34±1.97 vs. 8.84±1.32,2 hours:17.33±0.52 vs. 11.17±2.14,4 hours:17.83±0.98 vs. 12.67±2.06,6 hours:18.67±1.22 vs. 13.50±2.16;Raw at 0 hour:37.36±5.14 vs. 27.05±2.93,2 hours:43.94±6.58 vs. 31.95±3.56,4 hours:48.04±6.07 vs. 35.24±3.50, 6 hours:50.33±6.34 vs. 36.66±3.64;pulmonary compliance at 6 hours:2.28±0.18 vs. 1.86±0.37,all P0.05). Microscopic observation showed that cilia were partially detached,adhered and sparse in low VT group,while cilia in high VT group showed serious detachment and lodging. Remaining cilia were sparse,with lodging,and cellular structure was damaged. Lung tissue pathological injury score in the high VT group was significantly higher than that of low VT group(6.17±2.14 vs. 3.50±1.52,P0.05). Cilia were severely detached,adhered and lodging,and cellularity were not obvious in high VT with airway humidification group,and lung tissue pathological injury score was elevated significantly than that of the low VT with airway humidification group but without statistically significant difference(5.17±2.14 vs. 3.00±1.10,P>0.05). TNF-α and IL-8 concentrations showed no change in plasma and BALF in all groups during ventilation,and no significant difference was found among the groups. Conclusions Airway humidification can alleviate pathological lung injury,damage of cilia and cellular structure in trachea caused by mechanical ventilation with low and high VT. High VT with humidification can result in serious pulmonary edema.

Meta analysis on effect of heat moisture exchangers on airway humidification in mechanically ventilated patients / 重庆医学

Objective To assess the effectiveness and safety of heat moisture exchangers (HMEs) on the artificial airway humid-ification in the mechanically ventilated patients .Methods The related literature in the Cochrane Library ,PubMed ,Embase ,CNKI , VIP ,WanFang database and CBM from the establishment to March 2012 were retrieved ,then included the randomized controlled trial(RCT) and quasi-RCT on the effect of HMEs for the artificial airway humidification in the mechanically ventilated patients were performed the meta analysis by using RevMan 5 .1 .2 software .Results 19 RCT were included(involving 2 960 patients) , which were the random parallel controlled trials .The meta analysis results showed that HMEs could not reduce the incidence rate of ventilator-associated pneumonia(VAP)(RR=0 .78 ,95% CI 0 .61-1 .01 ,P=0 .06) ,also could not decrease the hospitalization mor-tality(RR=0 .94 ,95% CI 0 .83-1 .08 ,P=0 .40) ,the length of ICU stay(MD= -0 .32 ,95% CI -3 .13 -2 .50 ,P=0 .82) and the occurrence rate of catheter occlusion (RR=0 .65 ,95% CI 0 .22 -1 .93 ,P= 0 .44) ,the differences between the two groups had no statistical significance .But 5 RCT reported that using HMEs could reduce the patient′s costs .Conclusion HMEs can not reduce the incidence rate of VAP ,mortality ,length of ICU stay ,occurrence rate of airway occlusion ,but can cut down the patient′s cost . Due to the risk of bias existing in all included RCT and the low quality of the obtained evidences ,more strictly designed and imple-mented RCTs are needed to further verify thse evidences .