Intensive Care Medicine

, Volume 14, Issue 1, pp 1–9

A review of the mechanisms and methods of humidification of inspired gases

  • M. P. Shelly
  • G. M. Lloyd
  • G. R. Park
Review Articles


Adequate humidification of inspired gases is important to avoid the hazards of under- and over-humidification. However, each patient will have an optimal level of humidification and as the condition of the patient changes so may his humidification requirements. At present, equipment to monitor humidity is not sufficienty sophisticated to allow accurate breath by breath measurements of humidity within the airway. The estimation of humidification requirements must, therefore, be based on existing scientific evidence and clinical impressions. Humidification of inspired gases should not be considered in isolation but as part of total airway management. It should be associated with careful fluid balance, physiotherapy, bronchial aspiration and appropriate drug therapy.


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  1. 1.
    Walker JEC, Wells RE, Merrill EW (1961) Heat and water exchange in the respiratory tract. Am J Med 30:259CrossRefPubMedGoogle Scholar
  2. 2.
    Dery R (1971) Humidity in anaesthesiology IV: determination of the alveolar humidity and temperature in the dog. Can Anaesth Soc J 18:145PubMedGoogle Scholar
  3. 3.
    Dery R, Pelletier J, Jacques A, Clavet M, Houde JJ (1967) Humidity in anaesthesiology III: heat and moisture patterns in the respiratory tract during anaesthesia with the semi closed system. Can Anaesth Soc J 14:287PubMedGoogle Scholar
  4. 4.
    Dery R (1973) The evolution of heat and moisture in the respiratory tract during anaesthesia with a non-rebreathing system. Can Anaesth Soc J 20:269Google Scholar
  5. 5.
    Noguchi H, Takumi Y, Aochi O (1973) A study of humidification in tracheostomized dogs. Br J Anaesth 45:844PubMedGoogle Scholar
  6. 6.
    Chalon J, Loew DAY, Malebranche J (1972) Effect of dry anesthetic gases on tracheobronchial epithelium. Anesthesiology 37:338PubMedGoogle Scholar
  7. 7.
    Stone DR, Downs JB, Paul WL, Perkins HA (1981) Adult body temperature and heated humidification during general anesthesia. Anesth Analg 60:736PubMedGoogle Scholar
  8. 8.
    Marfatia S, Donahoe PK, Hendren WH (1975) Effect of dry and humidified gases on the respiratory epithelium in rabbits. J Paed Surg 10:583Google Scholar
  9. 9.
    Tattersal M (1982) Should we humidify our anaesthetic gases? A review. Anaesthesia points west 15:17Google Scholar
  10. 10.
    Fonkalsrud EW, Calmes S, Barcliff LT, Barrett CT (1980) Reduction of operative heat loss and pulmonary secretions in neonates by use of heated and humidified anesthetic gases. J Cardiovasc Surg 80:718Google Scholar
  11. 11.
    Chalon J, Patel C, Ali M, Ramanathan S, Capan L, Tang C-K, Turndorf H (1979) Humidity and the anesthetised patient. Anesthesiology (a) 50:195Google Scholar
  12. 12.
    Tsuda T, Noguchi H, Takima Y, Aochi O (1977) Optimum humidification of air administered to a tracheostomy in dogs. Br J Anaesth 49:965PubMedGoogle Scholar
  13. 13.
    Dalhamn T (1956) Mucus flow and ciliary activity in the trachea of healthy rats and rats exposed to respiratory irritant gases. Acta Physiol Scand [Suppl] 131:60Google Scholar
  14. 14.
    Burton JDK (1962) Effects of dry anaesthetic gases on the respiratory mucous membrane. Lancet 1:235PubMedGoogle Scholar
  15. 15.
    Forbes AR (1973) Humidification and mucus flow in the intubated trachea. Br J Anaesth 45:874PubMedGoogle Scholar
  16. 16.
    Forbes AR (1974) Temperature, humidity and mucus flow in the intubated trachea. Br J Anaesth 46:29PubMedGoogle Scholar
  17. 17.
    Fonkalsrud EW, Sanchez M, Higashijima I, Arima E (1975) A comparitive study of the effects of dry vs humidified ventilation on canine lungs. Surgery 78:373PubMedGoogle Scholar
  18. 18.
    Rashad K, Wilson K, Hurt HH, Graff TD, Benson DW (1967) Effect of humidification of anesthetic gases and static compliance. Anesth Analg Curr Res 40:127Google Scholar
  19. 19.
    Gawley TH, Dundee JW (1981) Attempts to reduce respiratory complications following upper abdominal operations. Br j Anaesth 53:1073PubMedGoogle Scholar
  20. 20.
    Knudsen J, Lomholdt N, Wisborg K (1973) Postoperative pulmonary complications using dry and humidified anaesthetic gases. Br J Anaesth 45:363Google Scholar
  21. 21.
    Editorial (1984) Are postoperative pulmonary complications preventable? Lancet 2:1079Google Scholar
  22. 22.
    Chalon J, Ali M, Ramanathan S, Turndorf H (1979) The humidification of anaesthetic gases: its importance and control. Can Anaesth Soc J (b) 26:361Google Scholar
  23. 23.
    Klein EF, Graves SA (1974) “Hot pot” tracheitis. Chest 65:225PubMedGoogle Scholar
  24. 24.
    Tamer MA, Modell JH, Rieffel CN (1970) Hyponatraemia secondary to ultrasonic aerosol therapy in the newborn infant. J Pediatr 77:1051PubMedGoogle Scholar
  25. 25.
    Mercke U (1975) The influence of varying air humidity on mucociliary activity. Acta Otolaryngol 79:133PubMedGoogle Scholar
  26. 26.
    Inglestedt S (1956) Studies on the conditioning of air in the respiratory tract. Acta Otolaryngol (Stock) 131:7Google Scholar
  27. 27.
    Weeks DB (1981) Evaluation of a disposable humidifier for use during anaesthesia. Anesthesiology 54:337PubMedGoogle Scholar
  28. 28.
    Chalon J, Ali M, Turndorf H, Fischgrund GK (1981) Humidification of anesthetic gases. Charles C Thomas, Illinois, p 12–17Google Scholar
  29. 29.
    Hilton PJ, Clement JA (1983) Surgical emphysema resulting from a ventilator malfunction. Anaethesia 38:342Google Scholar
  30. 30.
    James PD, Gothard JWW (1984) Possible hazard from the inserts of condenser humidifiers. Anaesthesia 39:70PubMedGoogle Scholar
  31. 31.
    Karis JH, O'Neal F, Weitzner SW (1980) Alteration of halothane in heated humidifiers. Anesth Analg 59:518PubMedGoogle Scholar
  32. 32.
    Equipment profile: heat and moisture exchangers and vaporising humidifiers (1986) Intensive Care World 3:29Google Scholar
  33. 33.
    Evaluation of humidifiers for medical use, Ultrasonic humidifiers (1984) Health Equipment Information, vol 128. Department of Health and Social SecurityGoogle Scholar
  34. 34.
    Ahlgren EW, Chapel JF, Dorn GL (1977) Pseudomonas aeruginosa infection potential of oxygen humidifier devices. Respiratory Care 22:383PubMedGoogle Scholar
  35. 35.
    Redding PJ, McWalter PW (1980) Pseudomonas fluorescence cross infection due to contaminated humidifier water. Br Med J 280:275Google Scholar
  36. 36.
    Malccka-Griggs B, Reinhardt DJ (1983) Direct dilution sampling, quantitation, and microbial assessment of open system ventilation circuits in intensive care units. J Clin Microbiol 17:870Google Scholar
  37. 37.
    Craven DE, Goularte TA, Make BJ (1984) Contaminated condensate in mechanical ventilator circuits a risk factor for nosocomial pneumonia. Am Rev Respir Dis 129:625PubMedGoogle Scholar
  38. 38.
    Im SWK, Fung JPH, So SY, Yu DYC (1982) Unusual dissemination of pseudomonads by ventilators. Anaesthesia 37:1074PubMedGoogle Scholar
  39. 39.
    Christopher KL, Saravolatz LD, Bush TL, Conway WA (1983) The potential role of respiratory therapy equipment in cross infection. Am Rev Respir Dis 128:271PubMedGoogle Scholar
  40. 40.
    Selwyn S (1972) Humidifiers in anaesthesia. Br Med J 1:51PubMedGoogle Scholar
  41. 41.
    Helgesen KG, Anderson R, Bergan T (1981) Prevention of bacterial spread in a respirator circuit. J Oslo City Hosp 31:133PubMedGoogle Scholar
  42. 42.
    Cheney FW, Butler J (1968) The effects of ultrasonically produced aerosols on airway resistance in man. Anesthesiology 29:1099PubMedGoogle Scholar
  43. 43.
    Modell JH, Moya F, Ruiz BC, Showers AV, Newby EJ (1968) Blood gas and electrolyte determinations during exposure to ultrasonic nebulised aerosols. Br J Anaesth 40:20PubMedGoogle Scholar
  44. 44.
    Chamney AR (1969) Humidification requirements and techniques. Anaesthesia 24:602PubMedGoogle Scholar
  45. 45.
    Shelly MP, Bethune DW, Latimer RD (1986) A comparison of five heat and moisture exchangers. Anaesthesia 41:527PubMedGoogle Scholar
  46. 46.
    Mapleson WW, Morgan JG, Hillard EK (1963) Assessment of condenser humidifiers with special reference to a multiple gauze model. Br Med J 1:300Google Scholar
  47. 47.
    Gedeon A, Mebius C (1979) The hygroscopic condenser humidifier. Anaesthesia 34:1043PubMedGoogle Scholar
  48. 48.
    Lloyd GM (1987) Heat and moisture exchangers: principles of operation. Intensive Care World (in press)Google Scholar
  49. 49.
    Revenas B, Lindholm CE (1979) Temperature variations in heat and moisture exchangers. Acta Anaesth Scand 23:34PubMedGoogle Scholar
  50. 50.
    Ogino M, Kopotic R, Mannino FL (1985) Moisture-conserving efficiency of condenser humidifiers. Anaesthesia 40:990PubMedGoogle Scholar
  51. 51.
    Walter AKY, Bethune DW (1976) A comparative evaluation of condenser humidifiers. Anaesthesia 31:1086Google Scholar
  52. 52.
    Weeks DB, Ramsey FM (1983) Laboratory investigation of six artificial noses for use during endotracheal anaesthesia. Anesth Analg 62:758PubMedGoogle Scholar
  53. 53.
    Mebius C (1983) A comparative evaluation of disposable humidifiers. Acta Anaesthesiol Scand 27:403PubMedGoogle Scholar
  54. 54.
    Powner DJ, Sanders CS, Bailey BJ (1986) Bacteriologic evaluation of the servo 150 hygroscopic condenser humidifier. Crit Care Med 14:135PubMedGoogle Scholar
  55. 55.
    Bygdeman S, Euler C von, Nyström B (1984) Moisture exchangers do not prevent patient contamination of ventilators. A microbiological study. Acta Anaesthesiol Scand 28:591PubMedGoogle Scholar
  56. 56.
    Daschner F (1984) Falsche hygienische Sicherheit durch Engstrom Edith Einmalbefeuchter. Anästh Intensivther Notfallmed 1:38Google Scholar
  57. 57.
    Leigh JM, White MG (1984) A new condenser humidifier. Anaesthesia 39:492PubMedGoogle Scholar
  58. 58.
    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 63:566PubMedGoogle Scholar
  59. 59.
    Bethune DW, Shelly MP (1985) Hydrophobic versus hygroscopic heat and moisture exchangers. Anaesthesia 40:210PubMedGoogle Scholar
  60. 60.
    Chalon J, Patel C, Ramanathan S, Turndorf H (1978) Humidification of the circle system. Anesthesiology 48:142PubMedGoogle Scholar
  61. 61.
    Ackerman MH (1985) The use of bolus normal saline instillations in artificial airways: is it useful or necessary? Heart Lung 14:505PubMedGoogle Scholar
  62. 62.
    Ophoven JP, Mammel MC, Gordon MJ, Boros SJ (1984) Tracheobronchial histopathology associated with high-frequency jet ventilation. Crit Care Med 12:829PubMedGoogle Scholar
  63. 63.
    Neu O, Hamilton L, Lineman J, Rich M, Murkowski C, Wilson A, Oechler H (1984) Long-term high-frequency ventilation in neonates. Crit Care Med 12:833PubMedGoogle Scholar
  64. 64.
    Ramanathan S, Sinha K, Arismendy J, Chanlon J, Turndorf H (1984) Humidification and airway pressures during high-frequency jet ventilation delivered through the suction-biopsy channel of a flexible bronchofiberscope. Crit Care Med 12:820PubMedGoogle Scholar
  65. 65.
    Smith BE (1985) The Penlon Bromsgrove high frequency jet ventilator for adult and paediatric use. Anaesthesia 40:790PubMedGoogle Scholar
  66. 66.
    Doyle HJ, Napolitano AE, Lippman R, Cooper KR, Duncan JS, Eakins K, Glauser FL (1984) Different humidification systems for high-frequency jet ventilation. Crit Care Med 12:815PubMedGoogle Scholar
  67. 67.
    Carlon GC, Barker RL, Benua RS, Guy YG (1985) Airway humidification with high-frequency jet ventilation. Crit Care Med 13:114PubMedGoogle Scholar
  68. 68.
    Weeks DB (1975) Humidification during anesthesia. NY State J Med 75:1216Google Scholar
  69. 69.
    Primiano FP, Moranz ME, Montague FW, Miller RB, Sachs DPL (1984) Conditioning of inspired air by a hygroscopic condenser humidifier. Crit Care Med 12:675PubMedGoogle Scholar
  70. 70.
    Oh TE, Thompson WR, Hayward DR (1981) Disposable condenser humidifiers in intensive care. Anaesth Intensive Care 9:331PubMedGoogle Scholar
  71. 71.
    McIntyre NR, Anderson HR, Silver RM, Schuler FR, Coleman RE (1983) Pulmonary function in mechanically ventilated patients during 24 hour use of a hygroscopic condenser humidifier. Chest 84:560Google Scholar
  72. 72.
    Gallagher J, Strangeways JEM, Allt-Graham J (1987) Contamination control in long term ventilation. Anaesthesia 42:476PubMedGoogle Scholar
  73. 73.
    Shelly MP, Park GR, Warren RE, Whetstone RJ (1986) Portable lung ventilators: the potential risk from bacterial colonisation. Intensive Care Med 12:328CrossRefPubMedGoogle Scholar
  74. 74.
    MacKuanying N, Chanlon J (1974) Humidification of anesthetic gases for children. Anesth Analog 53:387Google Scholar
  75. 75.
    Duncan A (1985) Use of disposable condenser humidifiers in children. Anaesth Intensive Care 13:330PubMedGoogle Scholar
  76. 76.
    Hannallah RS, McGill WA (1983) A practical way of using heated humidifiers with pediatric T-piece systems. Anesthesiology 59:156PubMedGoogle Scholar
  77. 77.
    Lomholt N, Cooke R, Lunding M (1968) A method of humidification in ventilator treatment of neonates. Br J Anaesth 40:335PubMedGoogle Scholar
  78. 78.
    Penderson B (1977) Intubation of newborns and infants: a solution to the problem of water condensation. Acta Anaesth Scand 21:534Google Scholar
  79. 79.
    Graff TD, Benson DW (1969) Systemic and pulmonary changes with inhaled humid atmospheres. Anesthesiology 30:199PubMedGoogle Scholar
  80. 80.
    Warner JO (1986) Medicine and the media. Br Med J 292:754Google Scholar

Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • M. P. Shelly
    • 1
  • G. M. Lloyd
    • 1
  • G. R. Park
    • 1
  1. 1.Addenbrooke's HospitalCambridgeUK
  2. 2.Department of AnaesthesiaRoyal United HospitalBathUK
  3. 3.Department of AnaesthesiaPall Biomedical LtdPortsmouthUK

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