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 .

The effect of a pediatric heat and moisture exchanger on dead space in healthy pediatric anesthesia / 대한마취과학회지

BACKGROUND: Heat and moisture exchangers (HME) are often used to maintain humidity of breathing circuits during anesthesia. It is also known to increase dead space ventilation in respiratory distress syndromes. However, the effect of a pediatric HME in healthy pediatric patients has not yet been clarified. The purpose of this study was to evaluate the effect of a pediatric HME on dead space in healthy pediatric patients during anesthesia. METHODS: 20 ASA physical class I pediatric patients, without respiratory impairment, who underwent elective surgery for inguinal hernia or hydrocele with general anesthesia were enrolled. Fifteen minutes after ventilation with and without pediatric HME (internal volume of 22 ml), hemodynamic variables, end tidal CO2, minute volume and airway pressure were measured, and arterial blood sampling was conducted simultaneously. RESULTS: The removal of pediatric HME decreased PaCO2 significantly from 46.1 +/- 6.9 mmHg to 37.9 +/- 4.3 mmHg (P < 0.001) and increased the pH from 7.32 to 7.37 (P < 0.001). The differences between PaCO2 with and without HME (Delta PaCO2) were significantly correlated with weight (P < 0.001, beta1 = -0.749) and age (P = 0.002, beta1 = -0.623). CONCLUSIONS: The use of a pediatric HME significantly increased PaCO2 in healthy pediatric patients that was inversely proportional to weight and age. The use of pediatric HME should be carefully considered in small pediatric patients.

Influence of heat and moisture exchanger on sputum of patients with tracheotomy receiving hyper baric oxygen treatment / 中国实用护理杂志

Objective To observe characters of sputum of patients with tracheotomy by heat and moisture exchanger(HEM)undergoing hyperbaric oxygen therapy(HBOT)in multi-person chamber.Methods In randomly block design,239 patients were selected and received HBOT using HEM combined with L-shape tube(group HEM,n=128)and by L-shape tube(group L,n=111)respectively.The characters and volume of sputum,times of sucking sputum and cases of sealing/extubation of tubes were assessed over first and tenth sessions of HBOT.Results The times of sucking and volume of sputum over first session of HBOT in the group HEM were more than those in group L.The sputum was changing from ropiness over first session to tenuity over tenth sesion(P＜0.01).Cases with sealing/extubation of tubes in group HEM were more than those of group L(P＜0.01).Conclusions It is helpful to humidify and discharge deposited sputum of patients over routine hyperbaric oxygen by HEM.And the case8 of sealing/extubation of tubes are also reduced.