			Home About us Contact

Moisture Exchanger (moisture + exchanger)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Assessment of tracheal temperature and humidity in laryngectomized individuals and the influence of a heat and moisture exchanger on tracheal climate

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2008
J. Karel Zuur MD
Abstract Background The beneficial function of heat and moisture exchangers (HMEs) is undisputed, but knowledge of their effects on intra-airway temperature and humidity is scarce. The aim of this study was to evaluate the clinical applicability of a new airway climate explorer (ACE) and to assess the HME's influence on tracheal climate. Methods Intratracheal temperature and humidity were measured with and without HME in 10 laryngectomized patients. Results An HME causes the intratracheal mean humidity minima to increase with 3.2 mg H2O/L (95% CI: 1.5,4.8 mg H2O/L; p <.001), from 21.4 to 24.6 mg H2O/L, and the mean temperature minima to decrease with 1.6°C (95% CI: 0.9,2.4°C; p <.001) from 28.5°C to 26.9°C. Relative humidity values suggest that the tested HME keeps inspired air (nearly) fully saturated during the full course of inspiration. Conclusion Assessment of intratracheal temperature and humidity, and evaluation of HME effectiveness is feasible with the ACE. The tested HME significantly increases the intratracheal humidity, but decreases the intratracheal temperature. Relative humidity calculations suggest that increasing the thermal capacity of this rehabilitation device can further increase the heat and moisture exchange efficiency. © 2008 Wiley Periodicals, Inc. Head Neck, 2008 [source]

A study of the effect of a resistive heat moisture exchanger (trachinaze) on pulmonary function and blood gas tensions in patients who have undergone a laryngectomy: A randomized control trial of 50 patients studied over a 6-month period

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 5 2003
Andrew Simpson Jones MD
Abstract Background. Previous work from this department has shown that resistive tracheostomy filters increase the partial pressure of oxygen in capillary blood and also provide a significant amount of heat/moisture exchange. Until now it has not been shown whether there is any long-term beneficial effect and in particular whether raised tissue oxygenation is maintained using a practical filter device. Methods. We carried out a 6-month randomized control trial including 50 laryngectomees. Twenty-five patients were treated with the Liverpool Heat Moisture Exchange device incorporating an airway resistor (Trachinaze). Another 25 patients were treated with a placebo device. Relevant subjective and objective data were collected before and at the end of the study. The objective measurements were capillary oxygen tension (which parallels blood arterial tension), carbon dioxide tension, FEV1, FVC, and PIF. Patients were reviewed at intervals throughout the study. Data were analyzed using the Mann,Whitney U test and the paired t test to test the difference between the active device and placebo at 6 months. Results. Subjective lower airway parameters, including cough, number of chest infections, mucus production, and shortness of breath at rest, were significantly improved in the active group compared with the placebo group. The objective parameters FEV1, FVC, and PIF were not significantly different. Capillary oxygen tension, however, was highly significantly raised in the active group at 6 months. Conclusions. Trachinaze is highly superior to placebo at improving subjective pulmonary parameters, including shortness of breath. It is also superior in its ability to maintain an increased peripheral tissue oxygen tension over a 6-month period. © 2003 Wiley Periodicals, Inc. Head Neck 25: 000,000, 2003 [source]

The effect of heat and moisture exchanger on humidity and body temperature in a low-flow anaesthesia system

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2003
A. Johansson
Background: Artificial humidification of dry inspired gases seems to reduce the drop in body temperature during surgery. The aim of this study was to evaluate the humidity and temperature of anaesthetic gases with heat and moisture exchangers (HMEs). The secondary aim was to evaluate if HMEs in combination with low-flow anaesthesia could prevent a decrease in the body temperature during general anaesthesia. Methods: Ninety patients scheduled for general surgery were randomised to receive a fresh gas flow of 1.0, 3.0 or 6.0 l min,1 with or without HMEs in a circle anaesthesia system. Relative humidity, absolute humidity, temperature of inspired gases and body temperatures were measured during 120 min of anaesthesia. Results: The inspiratory absolute humidity levels with HMEs were 32.7 ± 3.1, 32.1 ± 1.1 and 29.2 ± 1.9 mg H2O l,1 and 26.6 ± 2.3, 22.6 ± 3.0 and 13.0 ± 2.6 mg H2O l,1 without HMEs after 120 min of anaesthesia with 1.0, 3.0, or 6.0 l min,1 fresh gas flows (P < 0.05, between with and without HME). The relative humidity levels with HMEs were 93.8 ± 3.3, 92.7 ± 2.2 and 90.7 ± 3.5%, and without the HMEs 95.2 ± 4.5, 86.8 ± 8.0 and 52.8 ± 9.8% (P < 0.05, between with and without HMEs in the 3.0 and 6.0 l min,1 groups). The inspiratory gas temperatures with HMEs were 32.5 ± 2.0, 32.4 ± 0.5 and 31.0 ± 1.9°C, and 28.4 ± 1.5, 27.1 ± 0.8 and 26.1 ± 0.6°C without HMEs after 120 min of anaesthesia (P < 0.05, between with and without HME). The tympanic membrane temperatures at 120 min of anaesthesia were 35.8 ± 0.6, 35.5 ± 0.6 and 35.4 ± 0.8°C in the groups with HMEs, and 35.8 ± 0.6, 35.3 ± 0.7 and 35.3 ± 0.9°C in the groups without the HMEs (NS). Conclusions: The HMEs improved the inspiratory absolute humidity, relative humidity and temperature of the anaesthetic gases during different fresh gas flows. However, the HMEs were not able to prevent a body temperature drop during low-flow anaesthesia. [source]

Three cases of PICU sedation with isoflurane delivered by the ,AnaConDa®'

PEDIATRIC ANESTHESIA, Issue 10 2005
PETER V. SACKEY MD
Summary Prolonged sedation in the pediatric intensive care unit may be difficult because of tolerance, drug dependence and withdrawal, drug interactions and unwanted drug effects. We present three patients sedated with isoflurane via the Anesthetic Conserving Device, AnaConDa®. AnaConDa® is a modified heat and moisture exchanger that allows evaporation and delivery of inhalational anesthetics without an anesthesia machine, vaporizer or adapted ventilator. Two patients with abdominal complications and prolonged sedation for mechanical ventilation were converted to isoflurane sedation for several days. The third patient with refractory status epilepticus received isoflurane to treat epileptiform electroencephalogram activity. Patients weighing 40 and 30 kg were treated with AnaConDa® placed at the Y-piece, while the patient weighing 20 kg was treated with AnaConDa® in the inspiratory limb of the respiratory circuit. Adequate sedation was achieved with endtidal isoflurane concentration of 0.3,0.4%, while antiepileptic effect was achieved at a higher dose, 0.9%. Intravenous sedatives could be reduced or discontinued during isoflurane sedation. Inhaled sedation of isoflurane with AnaConDa® was effective in these patients. It may provide an alternative in difficult cases needing prolonged sedation and should be evaluated further. [source]

The effect of a heat and moisture exchanger on gas flow in a Mapleson F breathing system during inhalational induction

ANAESTHESIA, Issue 6 2000
J. M. G. Da Fonseca
Heat and moisture exchangers (HMEs) humidify, warm and filter inspired gas, protecting patients and apparatus during anaesthesia. Their incorporation into paediatric anaesthetic breathing systems is recommended. We experienced delays in inhalational induction whilst using a Mapleson F breathing system with an HME. We have demonstrated that the HME significantly alters gas flow within the breathing system. Approximately half of the fresh gas flow is delivered to the patient, the remainder being wasted into the expiratory limb of the breathing system. We suggest that the HME should be removed from the Mapleson F breathing system until inhalational induction is complete, or that the reservoir bag is completely occluded until an effective seal is obtained with the mask. [source]

Influence of breathing resistance of heat and moisture exchangers on tracheal climate and breathing pattern in laryngectomized individuals,

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2010
Renske J. Scheenstra MD
Abstract Background. The aim of this study was to determine the influence of breathing resistance of heat and moisture exchangers (HMEs) on endotracheal climate and breathing pattern. Methods. Endotracheal temperature and humidity and tidal volumes were measured in 11 laryngectomized patients with a regularly used HME with "standard" breathing resistance (Provox Normal HME; R-HME), a low breathing-resistance HME (Provox HiFlow HME; L-HME), and without HME. Results. Both R-HME and L-HME increased end-inspiratory humidity (+5.8 and 4.7 mgH2O/L, respectively), decreased end-inspiratory temperature (,1.6 and ,1.0°C, respectively), and prolonged the exhalation breath length to approximately 0.5 seconds. The R-HME significantly enlarged tidal volumes (0.07 L; p < .05). Conclusions. Both HMEs significantly improve tracheal climate. The R-HME has better moistening properties and a small but significant positive effect on tidal volume. Therefore, if the higher resistance is tolerated, the R-HME is the preferred pulmonary rehabilitation device. The L-HME is indicated if lower breathing resistance is required. © 2009 Wiley Periodicals, Inc. Head Neck, 2010 [source]