A heated humidifier does not reduce laryngo- pharyngeal complaints after brief laryngeal mask anesthesia

Duk-Kyung Kim, Ka-Young Rhee, Won-Kyoung Kwon, Tae-Yop Kim, Joo-Eun Kang
Canadian Journal of Anaesthesia 2007, 54 (2): 134-40

PURPOSE: Warming and humidification of inspired gases is standard care for intubated patients whose lungs are ventilated mechanically for prolonged periods. We examined whether active humidification of inspired gases might reduce laryngo-pharyngeal discomfort in patients undergoing brief laryngeal mask airway (LMA) anesthesia.

METHODS: In a prospective trial, 200 adult patients undergoing elective surgery under general anesthesia were randomly assigned to receive ventilation without airway warming and exogenous humidification (Group C-control), or active warming and humidification of inspired gases (Group HUM-humidified), using a humidifier with a heated wire circuit. Inhalational anesthesia was maintained via a circle system. The temperatures and relative humidities of inspired gases were monitored continuously throughout surgery. Postoperative sore throat, dysphonia, and dysphagia were assessed one and 24 hr after anesthesia. Whenever symptoms were present, their severities were graded using a 101-point numerical rating scale.

RESULTS: The mean temperature and relative humidity of the inspired gases in Group HUM were greater compared to Group C (36.1+/-0.4 degrees C and 99.5+/-0.5% vs 26.9+/-0.8 degrees C and 76.4+/-10.9%, respectively). Postoperatively, the overall frequencies of laryngeal and pharyngeal discomfort were similar in the two groups (53.8% and 54.9% in Group C vs 51.6% and 41.9% in Group HUM at one and 24 hr respectively, P>0.05). The groups were also similar with respect to the severity scores of laryngo-pharyngeal discomfort.

CONCLUSION: Active warming and humidification of inspired gases has no clinically appreciable effect in reducing the incidence and severity of laryngo-pharyngeal complaints after brief (<two hours) LMA anesthesia.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"