Relationship between the humidity and temperature of inspired gas and the function of the airway mucosa.

  title={Relationship between the humidity and temperature of inspired gas and the function of the airway mucosa.},
  author={R B Williams and Nigel Rankin and T Smith and D Galler and Paul John Seakins},
  journal={Critical care medicine},
  volume={24 11},
OBJECTIVE To review the available literature on the relationship between the humidity and temperature of inspired gas and airway mucosal function. [] Key MethodDATA SOURCES International computerized databases and published indices, experts in the field, conference proceedings, bibliographies. STUDY SELECTION/DATA EXTRACTION Two hundred articles/texts on respiratory tract physiology and humidification were reviewed.

Humidification During Invasive Mechanical Ventilation: Hygrometric Performances and Cost of Humidification Systems

In some clinical situations, such as patients ventilated with ARDS or severe asthma, other criteria than the level of humidification should be considered, in particular to take into account the mechanical characteristics of the different humidification systems (especially the dead space).

Influence of temperature and humidity of ambient air on sensation of dryness during respiration

  • S. Takada
  • Engineering
    Journal of the Human-Environment System
  • 2020
To create an optimal indoor thermal environment, it is necessary to identify the environmental conditions that cause a sensation of dryness. Dryness is experienced in various parts of the human body

Oxygen, temperature and humidity of inspired gases and their influences on airway and lung tissue in near-term lambs

In near-term neonatal lambs ventilated for 3 h, hyperoxia was associated with a more powerful stimulus for pulmonary dysfunction and upregulation of inflammatory cytokines than cold dry gas.

Energy balance in the intubated human airway is an indicator of optimal gas conditioning

Inspired gas at body temperature and saturated is thermodynamically neutral to the intubated airway, and thus may be considered the optimal condition for ventilation lasting more than a few hours.

Humidification in Intensive Care Medicine: General Approach to Selected Humidification Devices and Complications of Mechanical Ventilation

A model suggesting above or below optimal temperature, and humidity conditions can lead to impaired airway mucosal dysfunction, or, vice versa, that adequate mucociliary function is an indicator of ideal humidification is developed.

Influence of ambient and ventilator output temperatures on performance of heated-wire humidifiers.

An increase in inlet chamber temperature induced by high ambient temperature markedly reduces the performance of heated-wire humidifiers, leading to a risk of endotracheal tube occlusion, and such systems should be avoided in these conditions unless automatic compensation algorithms are used.

Effect of a heated humidifier during continuous positive airway pressure delivered by a helmet

The fresh gas flowing through the helmet with continuous flow CPAP systems limited the possibility to increase the humidity, and it is suggested that a heated humidifier should be employed withContinuous flowCPAP systems.

Efficacy of a heated passover humidifier during noninvasive ventilation: a bench study.

NPPV delivers air with a low relative humidity, especially with high inspiratory pressure, and addition of a heated humidifier increases the relative and absolute humidity to levels acceptable for nonintubated patients, with minimal effect on delivered pressure.

Mucociliary function deteriorates in the clinical range of inspired air temperature and humidity

Delivery of inspired gas at 30 °C, or even 34 °Cs, with 100% RH may not be sufficient to prevent epithelial damage occurring during 6 h exposure, and reduced air temperature led to a decrease in both CBF and MTV and, frequently, total mucociliary failure.

Comparison of the temperature and humidity in the anesthetic breathing circuit among different anesthetic workstations

There were statistical differences in the provision of humidity among different anesthesia workstations and the Cato and Primus workst stations were superior to Excel and Avance, however, even these were unsatisfactory in humans.



Water vapour and temperature dynamics in the upper airways of normal and CF subjects.

The data suggest that when the rate of evaporation is sufficiently high, the rate-limiting step may be water transport through the mucosal tissue and/or secretions, more evident for CF patients than for normal subjects.

Effect of air humidity on spinability and transport capacity of canine airway secretions.

It is suggested that lowering the AH of air induces a decrease in the transport capacity which appears to be dependent on the change of spinability that occurs in the mucus.

Effects of dry air and subsequent humidification on tracheal mucous velocity in dogs.

It is found that an artificial heat and moisture exchanger placed on the proximal end of an endotracheal tube partially protects against the suppression of tracheal mucous velocity caused by dry air breathing.

Humidification requirements and techniques

The aim of this paper is to review the requirements of the patient whose upper respiratory tract has been bypassed, to produce a specification for heater-humidifiers which is based on the probable physiological needs of these patients and to assess existing equipment by comparing its performance with that laid down in the specification.

A Comparative Evaluation of Disposable Humidifiers

Clinical experience as well as the extensive body of literature on humidification requirements support the conclusion that in most cases the new generation of heat and moisture exchangers, which have hygroscopic properties, are superior to conventional HME units.

The evolution of heat and moisture in the respiratory tract during anaesthesia with a non-rebreathing system

  • R. Déry
  • Medicine
    Canadian Anaesthetists' Society journal
  • 1973
The purpose of the work was to measure the heat and moisture pattern in the airways during clinical anaesthesia using a non-rebreathing system and to compare it with the semiclosed circle and normal patients at rest.

Water balance of the respiratory tract during ventilation with a gas mixture saturated at body temperature

  • R. Déry
  • Environmental Science
    Canadian Anaesthetists' Society journal
  • 1973
IT IS A WELL KNOWN FACT that every man breathing ambient air, either through his nose or mouth, undergoes a respiratory water deficit. This negative balance results from the expired air leaving the

The pressure of aqueous vapour in the alveolar air

To the authors' knowledge no direct measurement of the pressure of water vapour in the alveolar air has ever been made, and even from theoretical considerations it would seem probable that the figure which has been accepted is too high, and it would also seem possible that this value might readily show physiological variations.

Influence of temperature and decreased water content of inspired air on the ciliated bronchial epithelium. A physiological and electron microscopical study.

Experiments have been carried out on the bronchi and intrapulmonary airways of rats in vitro, to determine the physiological effects of air with water content (WC) of 2.19 mg/1, and ciliary beat frequency decreased with decreasing WC and irreversible ciliostasis was reached sooner, the lower the WC value.

Humidity of anaesthetic gases with respect to low flow anaesthesia.

Abstract It has been demonstrated in an experimental study in swine using the scanning electron microscope that a rebreathing technique utilising minimal fresh gas flowrates significantly improves