Abstract
Objectives
The purpose of this study was to build an experimental set-up to assess continuously the humidification, heating and resistance properties of heat-moisture exchangers (HMEs) under clinical conditions.
Design
The experimental set-up consists of a patient model, measurement systems and a ventilator.
Setting
Surgical ICU, University Hospital of Rotterdam.
Materials
A clinically used HME.
Measurements and results
The air flow, pressure in the ventilation circuit, pressure difference over the HME, and partial water vapour pressure and temperature at each side of the HME were measured. The resistance, absolute humidity, humidification efficiency and temperature difference at the patient side of the HME were calculated. Measurements were performed during 24h. The temperature output, humidity output and lung mechanics of the patient model were similar to values found in mechanically ventilated patients The measurement system was in agreement with the ISO draft standard and was capable of measuring dynamic variation of water and heat exchange over the range of a clinically used ventilator setting.
Conclusion
The experimental setup described is reliable for evaluating HMEs and can also be used for future clinical evaluation of HMEs. The main advantages of this set-up over those described previously are: (i) measurements of dynamic variations of water and heat exchange; (ii) on-line measurements of expiratory, as well as inspiratory resistance.
Article PDF
Similar content being viewed by others
References
Burton JDK, Lond MB (1962) Effects of dry anaesthetic gases on the respiratory mucous membrane. Lancet 3: 235–238
Tsuda T, Noguchi H, Takumi Y, Aochi O (1977) Optimum humidification of air administered to a tracheostomy in dogs. Br J Anaesth 49:965–976
Rashad K, Wilson K, Hurt HH, Graff TD, Benson DW (1967) Effect of humidification of anesthetic gases on static compliance. Anesth Analg 46: 127–133
Noguchi H, Takumi Y, Aochi O (1973) A study of humidification in tracheostomized dogs. Br J Anaesth 45: 844–847
Chalon J, Loew DAY, Malebranche J (1972) Effects of dry anesthetic gases on tracheobronchial ciliated epithelium. Anesthesiology 37:338–343
Shelly MP, Lloyd GM, Park GR (1988) A review of the mechanism and methods of humidification of inspired gases. Intensive Care Med 14:1–9
Mapleson WW, Morgan JG, Hillard EK (1963) Assessment of condenser humidifiers with special reference to a multiple gauze model. Br Med J 2:300–305
Gedeon A, Mebius C (1979) The hygroscopic condenser humidifier. Anaesthesia 34:1043–1047
Weeks DB, Ramsey FM (1983) Laboratory investigation of six artificial noses for use during endotracheal anesthesia. Anesth Analg 62:758–763
Ploysongsang Y, Branson R, Rashkin MC, Hurst JM (1988) Pressure flow characteristics of commonly used heatmoisture exchangers. Am Rev Respir Dis 138:675–678
Martin C, Perrin G, Gevaudan MJ, Saux P, Gouin F (1990) Heat and moisture exchangers and vaporising humidifiers in intensive care unit. Chest 97: 144–149
Roustan JP, Kienlen J, Aubas P, Aubas S, Cailar J (1992) Comparison of hydrophobic heat and moisture exchangers with heated humidifier during prolonged mechanical ventilation. Intensive Care Med 18:97–100
Evaluation report (1987) Heat and moisture exchangers. J Med Eng Tech 11:117–127
Gallagher J, Strangeways JEM, Allt-Graham J (1987) Contamination control in long-term ventilation. Anaesthesia 42:476–481
Berry AJ, Nolte FS (1991) An alternative strategy for infection control of anesthesia breathing circuits: A laboratory assessment of the Pall HMEs filter. Anesth Analg 72:651–655
Chalon J, Markham JP, Ali MM, Ramanathan S, Turndorf H (1984) The Pall Ultipor breathing circuit filter: An efficient heat and moisture exchanger. Anesth Analg 63:566–567
Eckerbom B, Lindholm CE (1990) Laboratory evaluation of heat and moisture exchangers. Assessment of the draft international standard (ISO/DIS 9360) in practice. Acta Anaesth Scand 34:291–295
International Organization For Standardization (1988) Heat and Moisture Exchangers for use in humidifying respired gases in humans. Draft International Standard (ISO/DIS 9360, 1988). 121:1–13
Medical Devices Directorate (1992) Heat and moisture exchanger (HMEs), Gibeck Humid-Vent filter. Evaluation 102:1–10
Mebius C (1983) A comparative evaluation of disposable humidifiers. Acta Anaesth Scand 27:403–409
Heat and Moisture exchangers. Evaluation. Health Devices Sourcebook 1983–84; 12:155–167.
Eckerbom B, Lindholm CE (1990) Performance evaluation of six heat and moisture exchangers according to the draft international standard (ISO/DIN 9360). Acta Anaesth Scand 34:404–409
Dery R (1973) The evolution of heat and moisture in the respiratory tract during anaesthesia with a non-rebreathing system. Can Anaesth Soc J 20: 296–309
Ingelstedt S (1956) Studies on the conditioning of air in the respiratory tract. Acta Otolaryngol Supp 131:1–81
McFadden ER, Pichurko BM, Bowman HF, Ingenito E, Burns S, Dowling N, Solway J (1985) Thermal mapping of the airways in humans. J Appl Physiol 58:564–579
Liese W, Warwick WJ, Cumming G (1974) Water vapour pressure in expired air. Respiration 31:252–261
Ferrus L, Guenard H, Vardon G, Varene P (1980) Respiratory water loss. Respir Physiol 39:367–381
Stoutenbeek Ch, Miranda D, Zandstra D (1982) A new hygroscopic condenser humidifier. Intensive Care Med 8: 231–234
Tilling SE, Hancox AJ, Hayes B (1983) An accurate method of measuring medical humidifier output. Clin Phys Physiol Meas 4:197–209
Primiano FP, Moranz ME, Montague FW, Miller RB, Sachs DPL (1984) Conditioning of inspired air by a hygroscopic condenser humidifier. Crit Care Med 12:675–678
Primiano FP, Montague FW, Saidel GM (1984) Measurement system for respiratory water vapour and temperature dynamics. J Appl Physiol 6:1679–1685
Conti G, De Blasi RA, Rocco M, Pelaia P, Antonelli M, Bufi M, Mattia C, Gasparetto A (1990) Effects of the heat-moisture exchangers on dynamic hyperinflation of mechanically ventilated COPD patients. Intensive Care Med 16:441–443
Arielli R, van Liew HD (1981) Corrections for the response time and delay of mass spectrometers. J Appl Physiol Respir Environ Exerc Physiol 51: 1417–1422
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ünal, N., Pompe, J.C., Holland, W.P.J. et al. An experimental set-up to test heatmoisture exchangers. Intensive Care Med 21, 142–148 (1995). https://doi.org/10.1007/BF01726537
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01726537