Hygroscopic Condenser Humidifier Research Articles

Effect of continuous heated humidification on artificial airway

Objective To investigate the effect of continuous heated humidification on critical patients with artificial airway. Methods 60 patients with artificial airway were randomly divided into experimental group and control group, 30 cases each group. Experimental group received continuous heated humidification and control group used artificial nose to humidify airway. To compare sputum viscidity, sputum scab, amyctic cough, respiration mucosa bleeding of two groups. Results There were significant differences between the two groups in sputum viscidity, sputum scab, amyctic cough, respiration mucosa bleeding (P ＜ 0. 05). Conclusions Continuous heated humidification can bring much better effects to patients than hygroscopic condenser humidifier. Key words: Artificial airway; Continuous heated humidification; Hygroscopic condenser humidifier

Comparison between these 3 following humidifiers when non-invasive ventilation is used: an heat and moisture exchanger booster (HMEB), an hot water humidifier (HWH) and an Hygroscopic condenser humidifier (HCH)

1Department of Anaesthesiology, St Luc Hospital, Université Catholique de Louvain, Brussels, Belgium

Respiratory gas conditioning in infants with an artificial airway

There is a strong physiological rational for delivering the inspiratory gas at or close to core body temperature and saturated with water vapour to infants with an artificial airway undergoing long-term mechanical ventilatory assistance. Cascade humidifiers with heated wire ventilatory circuitry may achieve this goal safely. Whenever saturated air leaves the humidifier chamber at 37°C and condensate accumulates in the circuit, the gas loses humidity and acquires the potential to dry airway secretions near the tip of the endotracheal tube. Heat and moisture exchangers and hygroscopic condenser humidifiers with or without bacterial filters have become available for neonates. They can provide sufficient moisture output for short-term ventilation without excessive additional dead space or flow-resistive load for term infants. Their safety and efficacy for very low birthweight infants and for long-term mechanical ventilation has not been established conclusively. A broader application of these inexpensive and simple devices is likely to occur with further design improvements. When heated humidifiers are appropriately applied, water or normal saline aerosol application offers no additional significant advantage in terms of inspiratory gas conditioning and may impose a water overload on the airway or even systemically. Although airway irrigation by periodic bolus instillation of normal saline solution prior to suctioning procedures is widely practised in neonatology, virtually no data exist on its safety and efficacy when used with appropriately humidified inspired gas. There is no evidence that conditioning of inspired gas to core body temperature and full water vapour saturation may promote nosocomial respiratory infections.

A Randomized Clinical Trial Comparing an Extended-Use Hygroscopic Condenser Humidifier With Heated-Water Humidification in Mechanically Ventilated Patients

To determine the safety and cost-effectiveness of mechanical ventilation with an extended-use hygroscopic condenser humidifier (Duration; Nellcor Puritan-Bennett; Eden Prairie, Minn) compared with mechanical ventilation with heated-water humidification. Prospective randomized clinical trial. Medical and surgical ICUs of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. Three hundred ten consecutive qualified patients undergoing mechanical ventilation. Patients requiring mechanical ventilation were randomly assigned to receive humidification with either an extended-use hygroscopic condenser humidifier (for up to the first 7 days of mechanical ventilation) or heated-water humidification. Occurrence of ventilator-associated pneumonia, endotracheal tube occlusion, duration of mechanical ventilation, lengths of intensive care and hospitalization, acquired multiorgan dysfunction, and hospital mortality. One hundred sixty-three patients were randomly assigned to receive humidification with an extended-use hygroscopic condenser humidifier, and 147 patients were randomly assigned to receive heated-water humidification. The two groups were similar at the time of randomization with regard to demographic characteristics, ICU admission diagnoses, and severity of illness. Risk factors for the development of ventilator-associated pneumonia were also similar during the study period for both treatment groups. Ventilator-associated pneumonia was seen in 15 (9.2%) patients receiving humidification with an extended-use hygroscopic condenser humidifier and in 15 (10.2%) patients receiving heated-water humidification (relative risk, 0.90; 95% confidence interval=0.46 to 1.78; p=0.766). No statistically significant differences for hospital mortality, duration of mechanical ventilation, lengths of stay in the hospital ICU, or acquired organ system derangements were found between the two treatment groups. No episode of endotracheal tube occlusion occurred during the study period in either treatment group. The total cost of providing humidification was $2,605 for patients receiving a hygroscopic condenser humidifier compared with $5,625 for patients receiving heated-water humidification. Our findings suggest that the initial application of an extended-use hygroscopic condenser humidifier is a safe and more cost-effective method of providing humidification to patients requiring mechanical ventilation compared with heated-water humidification.

Hygroscopic condenser humidifiers in chronically tracheostomized patients who breathe spontaneously

The aim of this study was to test the usefulness of hygroscopic condenser humidifiers on secretion and on inspired gas temperature in tracheostomized patients. Forty spontaneously breathing chronically tracheostomized patients were divided into two groups: Group 1 received a hygroscopic condenser humidifier connected to the tracheostomy, 24 h daily for 10 days; Group 2, without any protection system, was chosen as the control group. The daily number of tracheal suctions, quantity of aspirate and thickness and colouring of secretions was evaluated. At baseline, and at days 5 and 10, patients were submitted to blood gas analysis, respiratory function tests and sputum analysis. The temperature of gases breathed was measured at rest and during a hyperventilation test, with and without the hygroscopic condenser humidifier. Statistically significant differences were found in thickness and colouring of secretions between the two groups during the period of 10 days. Group 2 showed a significantly greater trend in number of bacteria than Group 1. The group with the hygroscopic condenser humidifier showed respiratory function improvement over time for forced expiratory volume in one second (FEV1) and tidal volume (VT), maximal inspiratory pressure (MIP), and maximal voluntary ventilation (MVV) in comparison to the control group, who did not. Significant differences in the temperature between rest and hyperventilation, with and without a hygroscopic condenser humidifier were also found. In conclusion, a hygroscopic condenser humidifier may be useful in chronically tracheostomized patients who breathe spontaneously, improving viscosity and colouring of secretions, preventing further bacterial colonization, heating inspiratory flow, and helping to improve the functional outcome.

Increased resistance of hygroscopic condenser humidifiers when using a closed circuit suction system

To examine a hygroscopic condenser after clinical use and to describe the interaction of a hygroscopic condenser and a closed circuit suction system used simultaneously. Prospective evaluation of hygroscopic condensers used clinically, and laboratory investigation of a hygroscopic condenser used with a closed circuit suction system. Tertiary referral centers. The hygroscopic condenser used during mechanical ventilation was removed and peak inflation pressure was measured by delivering a standard tidal volume and inspiratory flow across the isolated hygroscopic condenser while recording the peak inflation pressure. In the laboratory, four 10-mL aliquots of saline were instilled via closed circuit suction system into a test lung with fresh hygroscopic condensers (n = 15) inline. At baseline and after each instillation, the hygroscopic condenser was weighed and the peak inflation pressure was measured while in five condensers, peak expiratory flow rate was also measured. In these five devices, hygroscopic condenser resistance was measured with 100 L/min of constant gas flow while measuring the pressure drop across the hygroscopic condenser. In 11 hygroscopic condensers used for 27.5 +/- 11.9 hrs with no closed circuit suction system, the peak inflation pressure was 3.74 +/- 0.58 cm H2O. In the laboratory, instillation of saline via closed circuit suction system was associated with an increase in hygroscopic condenser weight. Peak inflation pressure increased in a quadratic fashion with the increase in hygroscopic condenser weight, while peak expiratory flow rate decreased in a linear fashion. After four saline instillations, hygroscopic condenser resistance increased from 5.66 +/- 0.31 to 13.9 +/- 2.42 cm H2O/L/sec. Clinical use of a hygroscopic condenser alone is not associated with a significant increase in peak inflation pressure. We caution the use of a hygroscopic condenser and a closed circuit suction system simultaneously, as an increase in hygroscopic condenser resistance may develop and may be poorly tolerated in patients with marginal ventilatory reserve.

Increased resistance of hygroscopic condenser humidifiers when using a closed circuit suction system

Increased resistance of hygroscopic condenser humidifiers when using a closed circuit suction system

Humidification in the Intensive Care Unit: Prospective Study of a New Protocol Utilizing Heated Humidification and a Hygroscopic Condenser Humidifier

Determine the utility of a proposed algorithm in allowing safe, efficient humidification in mechanically ventilated patients using both a hygroscopic condenser humidifier (HCH) and heated humidifier (HH). A prospective study using an algorithm to chose humidification devices based on physical examination and sputum characteristics. All patients admitted to the surgical ICU. One hundred twenty consecutive patients requiring mechanical ventilation (MV) were studied. Patients were examined by the attending respiratory care practitioner and given either an HCH or HH. If patients demonstrated any of the following--thick or tenacious secretions, core temperature < 32 degrees C, or bloody secretions--they were given an HH. All others used an HCH. If any of the above conditions occurred during HCH use, the patient was given an HH. Duration of ventilation, incidence of nosocomial pneumonia, ventilator circuit colonization, and mortality were determined for patients in each group. Cost of humidification devices, number of suctioning procedures per day, and volume of saline solution instilled were also recorded. Initially, 27 percent (32/120) of patients used an HH and 73 percent (88/120) used an HCH. During the study, ten patients required changing to an HH during HCH use. Patients in the HH group were more likely to have preexisting lung disease and had a longer duration of ventilation (83 +/- 21 h) and higher mortality (21 percent). Patients in the HCH group were more likely to be postoperative, had shorter durations of ventilation (38 +/- 14 h), and lower mortality (9 percent). There was no difference in the incidence of nosocomial pneumonia between the two groups (9 percent vs 6 percent) and endotracheal tube occlusion did not occur in either group. Circuit colonization was common in the HH group (64 percent) but rate in the HCH group (5 percent). Cost per day was significantly less for the HCH group ($4 vs $19.80). Patients who required a change from HCH to HH did so at a mean of 5 days. The proposed algorithm resulted in cost-efficient and safe application of humidification devices in patients in the surgical ICU.

Hygroscopic Condenser Humidifier as a Solution to Nasal Dryness Due to Nasal CPAP Treatment for Obstructive Sleep Apnea Syndrome

We report an apparent solution to nasal dryness for patients with obstructive sleep apnea syndrome treated with nasal continuous positive airway pressure (CPAP) when a hygroscopic condenser humidifier is introduced into the CPAP circuit. Six patients underwent a 5-h test period of nasal CPAP therapy with a mask containing a hygroscopic humidifier. The water vapor showed a statistically significant increase in both inspired and expired gases. The relative humidity of the inspired gases increased significantly. The levels of O2 and CO2 in the respired gases did not change. When patients were asked about nasal dryness at the end of the test, all of them reported marked improvement.

A capnographic caution

AnaesthesiaVolume 44, Issue 8 p. 693-693 Free Access A capnographic caution A. Yates, A. Yates Frenchlay Hospital, Bristol BS16 ILESearch for more papers by this authorJ.M. Eaton, J.M. Eaton Frenchlay Hospital, Bristol BS16 ILESearch for more papers by this author A. Yates, A. Yates Frenchlay Hospital, Bristol BS16 ILESearch for more papers by this authorJ.M. Eaton, J.M. Eaton Frenchlay Hospital, Bristol BS16 ILESearch for more papers by this author First published: August 1989 https://doi.org/10.1111/j.1365-2044.1989.tb13603.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 Pall Ultipor Breathing System Filter. Instructions for use. Pall Biomedical Ltd, Europa House, Havant Street, Portsmouth POI 3DP. 2 Chalon J, Markham JP, Ali MM, Ramanathan S, Turndorf H. The pall ultipor breathing circuit filter—an efficient heat and moisture exchanger. Anesthesia and Analgesia 1984; 63: 566– 70. 3 Primiano FP, Moranz ME, Montague FW, Miller RB, Sachs DPL. Conditioning of inspired air by a hygroscopic condenser humidifier. Critical Care Medicine 1984; 12: 675– 8. 4 Shelly M, Bethune DW, Latimer RD. A comparison of five heat and moisture exchangers. Anaesthesia 1986; 41: 527– 32. 5 Gallagher J, Strangeways JEM, Allt-Graham J. Contamination control in long-term ventilation. A clinical study using a heat- and moisture-exchanging filter. Anaesthesia 1987; 42: 476– 81. 6 Sohena J, Thompson J, Crone RK. Mechanical influences on the capnogram. Critical Care Medicine 1984; 12: 672– 4. 7 Buckley Pm. Increase in resistance of inline breathing filters in humidified air. British Journal of Anaesthesia 1984; 56: 637– 43. Volume44, Issue8August 1989Pages 693-693 ReferencesRelatedInformation

Neonatal hygroscopic condenser humidifier.

A hygroscopic condenser humidifier was developed for neonates on mechanical ventilation and was evaluated by laboratory tests and clinically. Humidification provided by the unit was measured in the 10- to 50-ml tidal-volume range at ambient temperatures of 24 degrees C and 38 degrees C. The effect of a leaking patient connection on device performance was investigated. Leakage rates were measured routinely in a neonatal ICU and surgery to determine the clinical significance. In the entire tidal volume and temperature range, the unit provided an inspiratory water content in excess of 30 g/m3 when the leak fraction (volume leaked/volume delivered at Y-piece) was less than 15%. This was found in three out of four cases. In about one out of ten cases, the leak exceeded 30%, which invariably led to corrective action, such as repositioning or changing the endotracheal tube. However, even at a 30% leak, a water content of about 26 g/m3 was still available for humidifying the inspired gas, which corresponds to normal physiologic conditions found in the trachea for nasal breathing of room air.

Bacteriologic evaluation of the Servo 150 hygroscopic condenser-humidifier.

The Servo 150 hygroscopic condenser-humidifier was evaluated during use to determine if the inner foam core became contaminated and if a bacteria-laden aerosol was produced during the inspiratory cycle of the patient's mechanical ventilator. Cultures from the core and of inspired gas were obtained from seven patients with known culture-positive sputum, after 4, 8, 12 and 24 h of humidifier use. In each case, the inner foam core was grossly contaminated after 4 h of use and colony counts increased during the 24-h testing period. The bacteria recovered were the same as those cultured from sputum. Despite the core's heavy bacterial growth, a bacteria-laden aerosol occurred in only 43% of the samples obtained during humidifier use. The Servo humidifier does not appear to increase the risk of airway exposure to airborne bacteria during mechanical ventilation.

Conditioning of inspired air by a hygroscopic condenser humidifier.

The heat and water content of inspired air is critical to the pulmonary viability of patients with artificial airways. By continuously measuring gas conditions in the ventilator circuits of 6 adult ICU patients, we studied the heat and water reclaimed from expired air by a hygroscopic condenser humidifier (HCH) in the circuit. Temperature, partial pressure of water vapor (PH2O) and relative humidity (RH) were determined at the tracheal outlet of the endotracheal tube. The HCH was 63% efficient; the end-inspiratory gas delivered to the patients averaged 30.9 degrees C with a PH2O of 32.5 mm Hg and an RH of 97.3% or, equivalently, an RH of 69.2% referenced to 37 degrees C. These values are lower than those reported in the literature for gas in the trachea during nose breathing of ambient air, but greater than the values reported for mouth breathing of ambient air.

A new hygroscopic condenser humidifier.

A new hygroscopic condenser humidifier for the mechanically ventilated patient has been tested. It functions as a heat and moisture exchange device (HME) with an additional hygroscopic sponge to minimize the water loss from the breathing circuit. A comparative in vitro study was undertaken with a conventional HME. The influence of tidal volume, inspiratory flow rate and minute volume on the relative humidity of the inspiratory gas and on the water loss was investigated. The new device provides adequate humidification within a broad scale of ventilatory settings. In a subsequent clinical test the hygroscopic condenser humidifier proved to be a simple and reliable way of humidification.

Efficacy of a new hygroscopic condenser humidifier.

A newly designed hygroscopic condenser humidifier was evaluated to assess efficacy of providing moisture to the airways in patients whose upper airways had been bypassed. With its use, the relative humidity of inspired gas fell with both increasing tidal volumes and especially increasing F10(2) due to the intrinsic dryness of medical oxygen. Under conditions other than high volumes and inspired oxygen, humidification appeared adequate. The device obviated many complications encountered with conventional heated nebulizers. It does add some degree of resistance in the ventilatory circuit which might be stressful during spontaneous breathing.

The Hygroscopic Condenser Humidifier. A new device for general use in anaesthesia and intensive care.

The design and performance of the Hygroscopic Condenser Humidifier (HCH) are described. In principle the HCH consists of two parts, a conventional Heat-Moisture-Exchanger (HME) and a hygroscopic unit. The hygroscopic action is shown to improve the water retention efficiency of the device by about a factor of two as compared with optimal HME designs. As a result, humidification levels corresponding to around 80% relative humidity at 37 degrees C are obtained in the trachea and this is also achieved when completely dry gases are delivered to the patient. The unit can therefore be used for all procedures in anaesthesia and in intensive care.