Design and application of a new heat-and-moisture exchanger with anti-splash sputum suctioning function / 中华危重病急救医学

In the emergency department, open endotracheal suctioning for mechanically ventilated patients with endotracheal intubation will lead to the spread of respiratory droplets and aerosols, polluting the surrounding environment and medical staff. The traditional heat-and-moisture exchanger has the effect of warming and humidifying, and can block pathogenic microorganisms, but it does not have the function of inserting a sputum suction tube. When the heat-and-moisture exchanger is pulled out for sputum suction, it is easy to cause sputum splash, which pollutes the surrounding environment and medical personnel. The addition of closed sputum suction devices will increase the economic burden on patients. Thus, the medical staff of emergency department of the First People's Hospital of Tongxiang City of Zhejiang Province designed a new type of heat-and-moisture exchanger with anti-splash sputum suctioning function and obtained the National Utility Model Patent of China (ZL 2021 2 0017615.0). The new heat-and-moisture exchanger is mainly composed of a receiving cavity, a connecting tube, a sputum suction tube intubation tube, a sealing valve, etc. The disposable sputum suction tube can be used to insert sputum suction, and at the same time, it can prevent the secretion from splashing to ensure sealing. The patent combines the humidification and pathogen blocking functions of the heat-and-moisture exchanger with the anti-splash sputum suctioning function, which is suitable for use in the emergency and critical care medicine departments and has clinically practical value.

Airway humidfi icationd urin g mechanical ventilation / 中国小儿急救医学

Humidificait on by artificial means must be provided when the upper airway is bypassed during mechanical ventilation.Enough humidification is very important during mechanical ventilation.Heated humidification( HH) and heta and moisture exchanger( HME) are the most commonly used types of artificial humidification in this situation.In this article, their advantages and disadvantages are itn roduced.HH na d HME are compared in humidification performance,effect no ventilator mechanics and association with venti-lation associated pneumonia.Depending on the clinical scenario, humidifier is reasonably selected, and the selection may changeo ver time according the treatment effect.

Effect of heat and moisture exchangers on the prevention of ventilator-associated pneumonia in critically ill patients

Ventilator-associated pneumonia (VAP) remains one of the major causes of infection in the intensive care unit (ICU) and is associated with the length of hospital stay, duration of mechanical ventilation, and use of broad-spectrum antibiotics. We compared the frequency of VAP 10 months prior to (pre-intervention group) and 13 months after (post-intervention group) initiation of the use of a heat and moisture exchanger (HME) filter. This is a study with prospective before-and-after design performed in the ICU in a tertiary university hospital. Three hundred and fourteen patients were admitted to the ICU under mechanical ventilation, 168 of whom were included in group HH (heated humidifier) and 146 in group HME. The frequency of VAP per 1000 ventilator-days was similar for both the HH and HME groups (18.7 vs 17.4, respectively; P = 0.97). Duration of mechanical ventilation (11 vs 12 days, respectively; P = 0.48) and length of ICU stay (11 vs 12 days, respectively; P = 0.39) did not differ between the HH and HME groups. The chance of developing VAP was higher in patients with a longer ICU stay and longer duration of mechanical ventilation. This finding was similar when adjusted for the use of HME. The use of HME in intensive care did not reduce the incidence of VAP, the duration of mechanical ventilation, or the length of stay in the ICU in the study population.

Research in the replacement of heated humidifiers with heat moisture exchangers during mechanical ventilation / 中国实用护理杂志

Objective To study the feasibility of using heat and moisture exchangers (HME)as an alternative to heated humidifiers (HH) in patients undergoing mechanical ventilation. Methods 266 pa-tients with mechanical ventilation admitted to our ICU over the recent 3 years were allocated to the experi-mental group (humidification with a heat and moisture exchanger) and the control group (with heated hu-midifier), and the effect of humidification, the reserved time of artificial airway, the time on mechanical yen-tilation, the time of stay in ICU, the ineidenee of ventilator-associated pneumonia (VAP) and the mor-tality rate were comparatively studied and analyzed. Results Significant differences were found between the experimental and the control group in effect of humidification, insufficiency of humidification or excessive hu-midification, airway spasm and time on mechanical ventilation and time of stay in ICU. The incidence of VAP in the control group was significantly higher than that in the experimental group. There were no significant dif-ference between the two groups in the reserved time of artificial airway and the mortality rate. There were no accident of humidification occurred in the experimental group while there were one case complicated with air-way burn and 11 eases complicated with choking with water in the control group. Conclusions We conclude that HH can be replaced by HME on mechanical ventilation while disease evolution and effect of humidification should be monitored closely and keep HME unobstructed.

A case of HME obstruction by distilled water from incidentally mounted heated wire circuit kit: A case report / 대한마취과학회지

Heat-moisture exchanger (HME) is an inexpensive and effective device used to prevent respiratory complications that can be caused by endotracheal tube insertion during general anesthesia. But, HME can increase airway resistance and be occluded by the patient's secretions. Whether a HME could be occluded by clear fluids such as condensate in the airway circuit is not certain yet. In vitro, a case of HME occlusion by normal saline was reported. We report a case of HME obstruction by distilled water came from the heated wire circuit which was unintentionally connected to the HME.

The effect of two types of humidifying devices on humidity of inspired gas and tidal volume by ventilator monitoring

BACKGROUND: In general anesthesia, a heat and moisture exchanger (HME) is used to prevent hypothermia and to maintain humidity of inspired gas. We hypothesized that after using a HME expiratory tidal volume decreases because a HME traps the expired vapor.The aim of this study was to evaluate the humidity of expired gas and to investigate the accuracy of tidal volume monitoring. METHODS: Forty patients undergoing elective surgery under general anesthesia were randomly allocated into two groups.Group P (n = 20) used Pall Breathing filter (pall BB25, ACE medical, Korea) and Group H (n = 20) used Hygrobac S (Mallinckrodt Dar, Mirandola, Italy) between endotracheal tube and Y-piece.And with same kind of ventilator, we measured expiratory tidal volume, temperature and relative humidity at before and after HEM.And we recorded expiratory tidal volume monitored by ventilator with and without HME. RESULTS: The relative humidity was significantly higher at before using HEM than after using HEM in both group.The temperature in Group H was higher when measured at before HME but not in Group P.The measured expiratory tidal volume at before and after HEM was not significantly different. The tidal volume monitored by ventilator with HEM was significantly smaller than without HEM, by 3.1% in Group P and 5.3% in Group H. CONCLUSIONS: The HMEs improve inspiratory humidity and temperature of anesthetic gas.But monitored expiratory tidal volume was underestimated when using HMEs.

Obstruction of Airway Filter/Heat and Moisture Exchanger during Cardiac Surgery: A case report / 대한마취과학회지

An acute obstruction of the breathing circuit during surgery can be a devastating situation. A 45-year old man who diagnosed with infective endocarditis and aortic valve regurgitation underwent emergency cardiac surgery. However, an obstruction of the breathing circuit occurred when the cardiopulmonary bypass was weaned. Fortunately, the ventilation normalized after removing the airway filter/heat and moisture exchanger (HME). We report this case of a HME obstruction of the breathing circuit with a review of the relevant literature.

Influence of Heat and Moisture Exchanger Filter on Temperature of Inspiratory and Endotracheal Gas / 医疗卫生装备

Objective To investigate the influence of heat and moisture exchanger filter(HMEF)on the temperature of inhaled and endotracheal gas during mechanical ventilation. Methods Thirty patients (ASAI-II) were selected and divided randomly into 2 groups: control group and HMEF group. The temperature of inhaled gas was monitored with hygrothermograph and the temperature of endotracheal gas was monitored with temperature probe. Baseline values were set at the moment of intubation and then the values were recorded at the first hour after intubation and the second hour after intubation. Results With the increase of the mechanical ventilation time, the temperature of inhaled and endotracheal gas decreased significantly in control group and increased significantly in HMEF group; The temperature of both inhaled and endotracheal gas in HMEF group were significantly higher than that in control group at the moment of the first hour after intuba- tion and the second hour after intubation; There was correlation between the temperature of inhaled gas and the temperature of endotracheal gas at the moment of intubation, but it was not the same at the moment of the first hour after intubation or the second hour after intubation. Conclusion HMEF can make the cold inhaled gas warmer when it reached the trachea; Temperature probe may be better than hygrothermograph for monitoring the temperature of trachea.