Mist Tents

I am sure that this subject has been gone over ad nauseam, but I am new to the help line so haven't seen any communications on this. I am trying to get rid of our mist tents and am looking for documentation to present our ped's committee. I have started to do a 'search' but would like to not reinvent the wheel so if anyone has the info I need at their finger tips I would greatly appreciate it.

my email is dmccarty@hisea.org and the fax number here is 907.796.8403.


Posted by Diane McCarty

Copy and pasted from previous posts...

Here's what I have saved and always post whenever this question comes up. This shoulg give you all the ammunition you need to discontinue croup tents:

Neto GM. Kentab O. Klassen TP. Osmond MH.

Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada. neto@cheo.on.ca

A randomized controlled trial of mist in the acute treatment of moderate croup.[see comment]. Comment in: Acad Emerg Med. 2003 Mar;10(3):289; author reply 289; PMID: 12615599 Academic Emergency Medicine. 9(9):873-9, 2002 Sep. Abstract

OBJECTIVE: To determine whether the use of mist improves clinical symptoms in children presenting to the emergency department (ED) with moderate croup.

METHODS: Children 3 months to 6 years of age were eligible for the study if they presented to the ED with moderate croup. Moderate croup was defined as a croup score of 2-7. The patients were randomly assigned to receive either mist (humidified oxygen) via mist stick or no mist. The patients had croup scores measured at baseline and every 30 minutes for up to two hours. At these intervals the following parameters were also measured: heart rate, respiratory rate, oxygen saturation, and patient comfort score. The patients were treated until the croup score was less than 2 or until two hours had elapsed. All patients initially received a dose of oral dexamethasone (0.6 mg/kg). Other treatments, such as racemic epinephrine or inhaled budesonide, were given at the discretion of the treating physician. The research assistants were unaware of the assigned treatments. RESULTS: There were 71 patients enrolled in the study; 35 received mist and 36 received no mist. The two treatment groups had similar characteristics at baseline. The median baseline croup score was 4 in both groups. The outcomes were measured as the change from baseline at 30, 60, 90, and 120 minutes. The change in the croup score from baseline in the mist group was not statistically different from the croup score change in the group that did not receive mist (p = 0.39). There was also no significant difference in improvement of oxygen saturation, heart rate, or respiratory rate at any of the assessment times. There was no adverse effect from the mist therapy. CONCLUSIONS: Mist therapy is not effective in improving clinical symptoms in children presenting to the ED with moderate croup.

1. “Comparative Evaluation of Oxygen Therapy Techniques”
Kory, et al. JAMA 1962; 179.10 767-772

2. “Colonization of Infants Exposed to Bacterially Contaminated Mists”
Moffett, Allan: AmerJDis Child; 1967:114 21-25

3. “The Myth of Mist Therapy”
Editorial; Parmar, Indian Journal of Pediatrics; Vol. 54, 5 615-618

4. “Oxygen Therapy in Pediatric Practice”
Kumar, Anthony, Sharma; Indian Pediatrics; Vol. 30 1993: 117-121

5. “Influence of mist tents….”
Rosenbluth & Chernick; Archives of Disease in Childhood: 49 1974:606-610

6. “The Measurement of Fluid…”
BAU et al; Pediatrics, Vol. 48, No. 4 Oct. 1971: 605-612

7. “Respiratory Deposition of Labeled Water…”
Wolfsdorf, Swift, Avery; Pediatrics Vol. 43, No. 5 May 1969: 799-808

8. “Mist Therapy in lower Respiratory Throat Infection”
Kelsch, et al; Amer. J Dis. Child; Vol. 109 June ’65: 495-499

9. “Regulation of O2 Concentration delivered to infants by N/C”
Vain, et al; AJDC; Vol. 143, Dec 1989: 1458-1460

10. “Moist Air in the TX of HB”
Edit Harry; Archives of Disease in Childhood; 1983: 58, 577

14. “How beneficial is mist test treatment”
Edit Kleiber; Pediatric Nursing; May-June 1989/ vol. 15/ #3

15. “Treatment of Croup”
Review; Skolnik; AJDC; Vol. 143, Sep 1989: 1045, 1049

16. “Management of Croup”
Edit. Council; Archives of Disease in Childhood; 1988, 63

17. “Humidification in viral Croup…”
Bourchier, Dawson, Ferguson; Aust. Paediatric J. (1984) 20: 289-291

18. “Treatment of Acute Viral Croup”
Lenney, Milner; Archives of Disease in Childhood; 1978, 53: 704-706

19. “Safer alternatives to mist leaf and cool aerosol TX”
Bob Dickerson, Minneapolis Children’s Hospital

20. “Guidelines for Prevention of Nasal Canal Pneumonia”
Resp. Care; Dec ’94; vol. 39 #12: P.1201

Posted by Michael McPeck


Try this:


"Results: Only 2 published studies have attempted to evaluate humidification therapy for croup, and none has been

published since 1984.

There is no published evidence to support the commonly held empirical view that humidity helps alleviate the symptoms of childhood croup..." (http://www.caep.ca/004.cjem-jcmu/004-00.cjem/vol-3.2001/v33-209.htm)

"Pediatric Medicine (Williams & Wilkins 1994) describes as follows;

It is important not to have a high density of mist in the tent since mist can exacerbate bronchospasm in these infants: rather, oxygen should be humidified, but water droplets should be evaporated before the infant breathes them." (http://www.pcc.com/lists/pedtalk.archive/9702/0025.html)

"Mist therapy is not effective in improving clinical symptoms in children presenting to the ED with moderate croup." (Neto GM. Kentab O. Klassen TP. Osmond MH. A randomized controlled trial of mist in the acute treatment of moderate croup. Academic Emergency Medicine. 9(9):873-9, 2002 September).

Inhalation of aerosolized water can be dangerous (e.g., Saetta M, Di Stefano A, Turato G, et al. Fatal asthma attack during an inhalation challenge with ultrasonically nebulized distilled water. J Allergy Clin Immunol. 1995;95:1285-7).

"6.0 HAZARDS/COMPLICATIONS: 6.1 Wheezing or bronchospasm(1,3,5,6)" (http://www.rcjournal.com/online_resources/cpgs/blandcpg.html)

"Most young children placed in mist tents find the experience frightening and careful observation of the child is rendered more difficult. This advice regarding humidified air originated in an era when many children who died from upper airway obstruction could be shown to have bacterial infection (either primary or secondary) and little other definitive therapy was possible, it being argued that humidification would be useful to loosen airway secretions. In fact, the only randomised trial of humidification in croup ever undertaken failed to show any benefit, although the number of patients in this study was very small. In an animal model of croup, in which airway oedema was induced by inflicting a mild thermal injury, humidified air was shown to result in greater airway resistance than dry air, while air temperature was shown to have little effect. Nebulised saline has not been shown to result in any sustained improvement in clinical status when used as a placebo treatment in trials involving nebulised adrenaline or budesonide. The use of humidified air was abandoned in most Australian children's hospitals more than a decade ago, without any observable deterioration in clinically important parameters such as the proportion of children requiring admission to intensive care or intubation or the length of hospital stay. There seems little reason to discourage the use of bathroom steam for children with croup in the home setting, particularly as the reduction in anxiety which both child and parent experience may be clinically useful, but it should be recognised that this is almost certainly a placebo effect and there is no evidence to support the continuing use of mist therapy in inpatient environments." (Macdonald, William B G; Geelhoed, Gary C. Management of childhood croup.(1997). Thorax;52(9),757-759).

"Once-popular mist tents have been abandoned." (Andrews JS, DeAngelis CD. Pediatrics. (1995). JAMA;273(21),1708-1710).

"The use of humidified air remains an option of unproved efficacy." (Jaffe DM. The Treatment of Croup with Glucocorticoids. (1998). NEJM;339(8),553-555).

"No therapeutic benefit was demonstrated from the provision of a high humidity atmosphere. The widespread use of humidification in the management of croup requires reappraisal." (Bourchier D, Dawson KP, Fergusson DM. Humidification in viral croup: a controlled trial. Aust Paediatr J 1984;20:289-91).

"In ten normal subjects the ultrasonic mist of H2O doesn't produce any functional change, while in thirteen asthmatic patients it results in a clear-cut bronchoconstriction..." (Allegra L. Bianco S. Non-specific broncho-reactivity obtained with an ultrasonic aerosol of distilled water. European Journal of Respiratory Diseases - Supplement.106:41-9, 1980).

Posted by Bret Fields


Further, the CDC's "Guidelines for Preventing Health-Care--Associated Pneumonia, 2003:

Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee" state the following:

c. Do not use large-volume room-air humidifiers that create aerosols (e.g., by venturi principle, ultrasound, or spinning disk and thus are really nebulizers) unless they can be sterilized or subjected to high-level disinfection at least daily and filled only with sterile water (II) (242,243)

Here's the two references the CDC Guidelines cite:

242. Woo AH, Yu VL, Goetz A. Potential in-hospital modes of transmission of Legionella pneumophila. Demonstration experiments for dissemination by showers, humidifiers, and rinsing of ventilation bag apparatus. Am J Med 1986;80:567--73.

243. Zuravleff JJ, Yu VL, Shonnard JW, Rihs JD, Best M. Legionella pneumophila contamination of a hospital humidifier: demonstration of aerosol transmission and subsequent subclinical infection in exposed guinea pigs. Am Rev Respir Dis 1983;128:657--61.

Posted by Michael McPeck


I wholly agree with Brian. Please store this so that all other queries can be sent to a conclusive link.

Jimmy, We stopped using all tents, cubes or whatever, nearly four years ago thanks in part to the folks that have responded here. In addition, some of our resources came from the AARC Clinical Practice Guidelines for Bland Aerosol Delivery (potential bronchospasm for inflamed airways) and the Cincinatti Guidelines for Bronchiolitis, indicating that no benefits were seen with patients in tents.

Eventually, my lit search turned around. After not finding anything to support the use of tents, the doctors were challenged to find anything that does.

Case closed.

Good luck,


Posted by Steven Klyce


Okay, I'm not finished on the subject...

At the pediatric facility where I have worked for over 21 years we had all of our 13 tents running everyday, every winter. We did change to the cubes for kids under six months. Then, the intelligence of a new director challenged the sour, conventional wisdom. Our LOS and severity of cases has changed dramatically in the last seven years by eliminating the use of tents and Spags.

The sad part of our story is that a decision was made to donate some of the tents to a rural facility. Once, a suggestion was made here to donate tents to a third world country. WELL, if tents don't work here why should they work any better in a third world country. Twice this year we have received patients from the rural hospitals that used our donated tents, admitted to PICU. Comically, a couple of our tents were donated to the local zoo. I can't imagine the post-op tigers responding any better than the babies with RSV.

Posted by Steven Klyce

Posted by Bret Fields

You all are getting good at this!!!

Thanks for all the help I received from the AARC help line. I presented the above information and was successful with our physicians in eliminating CT and Room humidifiers.

Posted by Candace Tabor

In the rural mountain hospitals I work in, we see mist tents used more as oxygen delivery devices, especially on RSV-positive kids who won't wear a cannula (with overindulgent parents who won't enforce wearing them). Any thoughts on the use of a tent for that purpose?

Jerry Meurs

Leadville, CO

Posted by Gerald Meurs


I attended an Asthma Educator Course in which the physician was asked about the use of croup tents. After laughter, he responded with the following statements:

Increased moisture will CAUSE wheezing.

Increased moisture will cause bronchospasm in asthmatics.

Increased humidification increases secretions.

Makes RSV worse.

Too much area to oxygenate.

Loose oxygen when opened only briefly.

They have been removed from most hospital 10 years ago. Grows bacteria then it is circulated in the room by blowers.

Takes high amounts of O2 flow to obtain small amount of O2 in tent.

Most Neonates and pediatric patients can be oxygenated with a NC and probably will require low flows, such as 0.5 liters.

All ages will leave on the cannula if there is a piece of tegaderm placed on each cheek to hold in place. He even said they would probable go home with the tegaderm - don't want pulled off.

And when he has smaller hospitals requesting a transfer to his hospital, his first question is, Are they in a tent? If so, he asks them to remove the patient from the tent and call him back in 30 minutes. He said they are frequently better in 30 min. not requiring transfer.

This physician said he would be glad to talk to any area physicians regarding this matter. His name is Dr. Jamshed Kanga, Department of Pediatrics, at the University of Kentucky, 859-323-6211.

The above statements should NOT be taken as a direct quote from him, because I wrote them and I’m sure I did not get them down exactly as he said them.

Jerry, with the information from Dr. Kanga in my opening proposal letter and the information above from the AARC help line, I did not have any problems with the MD's here. We are also a rural hospital and it seems like we are the last to catch on. (No insult intended, just seems to be fact) All the rural hospitals around me are still using them. I offered to sell them mine….

I went through the information given on the help line and highlighted the best info so they did not have to read it all. One of our physicians trained in Kosair's Children's Hospital and they asked him what he thought about it all; he confirmed the information and approval to remove the croup tents and room humidifiers was given. I would be glad to send you what I submitted to them, but it is all above for you to print.

There is enough information provided by the Respiratory Therapist above (with references) to support your case.

Posted by , 6/15/2005 3:04:32 PM

For Jerry Meurs,

As you search the information laid out on these threads you will find that a tent is especially not indicated in RSV. My post from earlier had to do with two decades of experience where it is likely the use of tents actually made kids worse. Children with RSV are often accepting of a cannula with Tegaderm, or we use Tender Grips. As with everything with peds, this takes patience and perseverance. It sure helps if parents cooperate. It took nearly two years to convince all the MDs to get rid of tents. Hope it takes everyone else less time with the info you find here.

Posted by Steven Klyce, 6/17/2005 9:16:44 PM

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