Otolaryngology http://oto.sagepub.com/
-- Head and Neck Surgery
Effects of Buffered Saline Solution on Nasal Mucociliary Clearance and Nasal Airway Patency
Bounmany K. Keojampa, Mai Hoang Nguyen and Matthew W. Ryan
Otolaryngology -- Head and Neck Surgery 2004 131: 679
DOI: 10.1016/j.otohns.2004.05.026
The online version of this article can be found at:
http://oto.sagepub.com/content/131/5/679
Published by:
http://www.sagepublications.com
On behalf of:
American Academy of Otolaryngology- Head and Neck Surgery
Additional services and information for Otolaryngology -- Head and Neck Surgery can be found at:
Email Alerts: http://oto.sagepub.com/cgi/alerts
Subscriptions: http://oto.sagepub.com/subscriptions
Reprints: http://www.sagepub.com/journalsReprints.nav
Permissions: http://www.sagepub.com/journalsPermissions.nav
>> Version of Record - Nov 1, 2004
What is This?
Downloaded from oto.sagepub.com at Harvard University on February 27, 2013
Effects of buffered saline solution on nasal mucociliary
clearance and nasal airway patency
BOUNMANY K. KEOJAMPA,
BS,
MAI HOANG NGUYEN,
MD,
and MATTHEW W. RYAN,
OBJECTIVE: To compare the effects of buffered hypertonic and buffered normal saline nasal spray on
mucociliary clearance and nasal airway patency.
STUDY DESIGN AND SETTING: Double-blind trial with
subjects acting as their own controls. Tertiary care
academic medical center.
RESULTS: Buffered hypertonic saline and buffered
normal saline both improved saccharine clearance
times (P < 0.0001 for buffered hypertonic and P ⴝ
0.002 for buffered normal saline). Buffered hypertonic saline improved saccharine clearance times
more than buffered normal saline (39.6% vs 24.1%, P
ⴝ 0.007). Neither buffered hypertonic nor buffered
normal saline significantly affected nasal airway
patency.
CONCLUSIONS: Both buffered hypertonic and buffered normal saline nasal spray significantly improved saccharine clearance times without affecting nasal airway patency. Buffered hypertonic
saline affected saccharine clearance times to a
greater degree than buffered normal saline.
CLINICAL SIGNIFICANCE: Buffered hypertonic and
buffered normal saline sprays both improve mucociliary clearance and should therefore be beneficial in conditions such as rhinitis and sinusitis, which
are associated with disruption of mucociliary clearance. However, these sprays do not appear to affect the nasal airway. Patients may therefore benefit from other treatments for “nasal congestion.”
EBM rating: B-2. (Otolaryngol Head Neck Surg
2004;131:679-82.)
F
or many years, topical saline solutions have been
used after nasal surgery and in the treatment of rhinitis
and sinusitis. Nasal irrigation with saline helps clear
From The University of Texas Medical Branch (Mr Keojampa and Dr
Nguyen) and The University of Texas Medical Branch Department of
Otolaryngology, Galveston, TX (Dr Ryan).
Presented at the 2004 Annual Meeting of the American Academy of Otolaryngology–Head and Neck Surgery, New York, NY, September 19-22, 2004.
Reprint requests: Matthew W. Ryan, MD, The University of Texas Medical
Branch, Department of Otolaryngology, Room 7.104, John Sealy Annex, 301
University Boulevard, Galveston, TX 77555-0521; e-mail, mwryan@
utmb.edu.
0194-5998/$30.00
Copyright © 2004 by the American Academy of Otolaryngology–Head and
Neck Surgery Foundation, Inc.
doi:10.1016/j.otohns.2004.05.026
MD,
Galveston, Texas
nasal secretions and infective debris and minimizes
crusting, which may obstruct normal sinonasal drainage. Saline also appears to improve the mucociliary
transport function of the nasal mucosa. Available evidence suggests that buffered hypertonic saline is superior for this purpose when compared to buffered normal
saline. For example, Talbot et al showed a 17% decrease in mucociliary clearance times in normal healthy
subjects after the instillation of a 3% buffered hypertonic saline solution.1 The relative superiority of buffered hypertonic saline is far from settled, however, as
buffered hypertonic saline may cause significant burning, limiting its use in some patients. And, although
there is little evidence to support this assertion, it has
been suggested that buffered hypertonic saline solutions may act to decongest the nasal mucosa, thereby
improving nasal breathing1 or providing added benefits
to patients with inflamed nasal mucosa.
The purpose of this study was to compare the effect
of buffered hypertonic and buffered normal saline
sprays on mucociliary clearance (as assessed by the
saccharine clearance method) and to use acoustic rhinometry to examine changes in nasal cavity dimensions
after the instillation of these sprays. Acoustic rhinometry is a quick, noninvasive, and reliable method of
measuring nasal patency. By using sound pulses and
analyzing the reflections, acoustic rhinometry can objectively measure nasal cavity cross-sectional area as a
function of distance from the nose. The reliability of
such measurements has been confirmed using correlation studies with computed tomography and magnetic
resonance imaging.2-5
MATERIALS AND METHODS
Twenty-two healthy volunteers participated in the
study. Informed consent was obtained from all subjects,
and this study was approved by the UTMB Institutional
Review Board for research involving human subjects.
Subjects taking nasal medication or who disclosed a
history of significant allergies, smoking, rhinitis, or an
upper respiratory tract infection within three weeks
prior to the study were excluded.
Nasal patency was measured with an acoustic rhinometer from Rhinometrics (Interacoustics, Assens,
Denmark), using the Rhinoscan software system. The
rhinometer was calibrated before each use. Three separate measurements were recorded to ensure reproducibility, and the average was calculated. Data was re679
Downloaded from oto.sagepub.com at Harvard University on February 27, 2013
Otolaryngology–
Head and Neck Surgery
November 2004
680 KEOJAMPA et al
ported as MCA1, the minimum cross-sectional area
detected in the distance between 0 and 22 mm, and
MCA2, the minimum cross-sectional area between 22
and 54 mm (Fig 1).
Mucociliary clearance was measured by using the
saccharine clearance test method.6 Subjects sat with
their heads upright, and a small piece of saccharine was
placed on the medial aspect of their inferior turbinate 1
to 1.5 cm behind the nasal vestibule using an ear
curette. After saccharine placement, subjects were
asked to avoid sniffing or sneezing. The clearance time
was then noted as the time elapsed at the subjects’ first
perception of a sweet taste.
Data collection was conducted on two separate days,
using 3% hypertonic saline one day and 0.9% normal
saline (both buffered to pH 7.6 with bicarbonate) the
other. Both investigator and subject were blinded to the
content of the solution used each day. On the first day,
subjects were randomly assigned a saline solution; on
their subsequent visit, subjects would receive the alternate saline solution.
On each day, a baseline acoustic rhinometry measurement was followed by a control saccharine clearance time. Then, subjects were given 10 sprays to one
side of the nose using an atomizing sprayer of either a
3% buffered hypertonic saline solution or a 0.9% buffered normal saline solution. After 10 minutes, a second
saccharine clearance time and acoustic rhinometry
measurement were obtained. The same procedure was
then repeated on a different day with the alternate saline
solution.
Paired data obtained before and after intervention
for the same day and same nasal cavity were compared,
providing a control for physiological variances such as
the nasal cycle or other daily variations which might
have affected the mucociliary clearance patterns of the
nose.7,8 Wilcoxon’s signed rank test was used to analyze changes in mucociliary clearance time and nasal
cavity cross-sectional area.
RESULTS
Changes in saccharine clearance time are shown in
Figure 2 and compare the percentage difference in
saccharine clearance times. The saccharine clearance
data was not normally distributed. There was no significant difference in control values between the solutions (P ⫽ 0.709), with mean control times of 13.3
minutes for buffered hypertonic saline and 13.0 minutes for buffered normal saline.
In 3% buffered hypertonic saline trials, mucociliary
clearance times decreased from baseline by 39.6%
(mean improvement of 349 seconds [5.8 min.] with SD
⫽ 266.9, P ⬍ 0.0001). In buffered normal saline trials,
mucociliary clearance times decreased by 24.1% (mean
Fig 1. Acoustic rhinometry graph of right and left nasal
cavity with depiction of MCA1 and MCA2. MCA1 is the
minimum cross-sectional area detected in the distance
between 0 and 22 mm, and MCA2 is the minimum crosssectional area between 22 and 54 mm.
improvement of 267 seconds [4.5 min.] with SD ⫽
368.8; P ⫽ 0.002). Buffered hypertonic saline improved mucociliary clearance times 15.5% more than
buffered normal saline (absolute difference, P ⫽
0.007).
Instillation of buffered hypertonic saline increased,
on average, MCA1 by 0.03 cm2 (SD ⫽ 0.165; P ⫽
0.580) and MCA2 by 0.07 cm2 (SD ⫽ 0.221; P ⫽
0.903). Buffered normal saline increased MCA1 by
0.03 cm2 (SD ⫽ 0.095; P ⫽ 0.927) and MCA2 by 0.02
cm2 (SD ⫽ 0.243; P ⫽ 0.676). In buffered hypertonic
saline trials, MCA1 increased from baseline 7.1% (P ⫽
0.687) and MCA2 increased 10.1% (P ⫽ 0.856). In
buffered normal saline trials, MCA1 increased from
baseline 6.8% (P ⫽ 0.938) and MCA2 increased 4.9%
(P ⫽ 0.720). The difference was not statistically sig-
Fig 2. Percentage difference in saccharine clearance
times between buffered hypertonic and buffered normal
saline.
Downloaded from oto.sagepub.com at Harvard University on February 27, 2013
Otolaryngology–
Head and Neck Surgery
Volume 131 Number 5
KEOJAMPA et al 681
nificant between buffered hypertonic saline and buffered normal saline, with P ⫽ 0.395 for MCA1 and P ⫽
0.676 for MCA2. The results for nasal patency are
shown in Figure 3.
The data did not show a correlation between improved mucociliary clearance times with buffered hypertonic saline instillation and changed nasal patency.
Additionally, the acoustic rhinometry results demonstrated a decrease in MCA1 and MCA2 values (decreased airway dimensions) in 7 out of 22 subjects in
buffered hypertonic saline trials and 6 out of 22 subjects in buffered normal saline trials.
DISCUSSION
Topical saline solutions are commonly used in the
treatment of rhinitis and sinusitis, and the beneficial
effects of this treatment may be related to improved
mucociliary clearance. Nasal mucociliary clearance
may be impaired by several factors: decreased ciliary
beat frequency, increased viscosity of the mucus layer,
outflow obstruction, crusting, mucosal contact, and altered ventilation. Impaired mucociliary function is associated with upper respiratory tract infections, allergic
rhinitis, and rhinosinusitis.9,10 This study compared the
effects of buffered hypertonic or buffered normal saline
nasal spray on saccharine clearance times and nasal
airway dimensions in normal volunteers. Despite the
rational basis for using saline solutions and the widespread use of these solutions for the management of
rhinosinusitis, uncertainty persists regarding what is the
ideal solution for topical intranasal application.
The saccharine clearance test has been shown to be
a reliable method of assessing mucociliary clearance
times and is closely correlated to the clearance rates
with tagged insoluble particles, which have been considered the most accurate technique.11 This test, in both
Fig 3. Average minimal cross-sectional area (MCA) before and after administration of buffered hypertonic and
buffered normal saline solutions.
the research and clinical setting, has become a useful
tool because it is inexpensive and easily performed.
The results of this study corroborate the findings of
Talbot et al,1 reinforcing the fact that buffered hypertonic saline improves mucociliary clearance. Additionally, the results from this study show that buffered
normal saline significantly improves mucociliary clearance. With buffered hypertonic saline, clearance times
decreased in 21 out of 22 subjects (95%). Unlike the
results of Talbot et al, this study showed that buffered
normal saline decreased mucociliary clearance times in
17 out of 22 subjects (77%). But overall, buffered
hypertonic saline decreased mucociliary clearance
times more than buffered normal saline in 15 out of 22
subjects (68%). Therefore, while both solutions improve mucociliary clearance, the effects of buffered
hypertonic saline are more profound. Whether buffered
hypertonic saline should be used in lieu of buffered
normal saline is still an unanswered question, however.
An additional goal of this study was to assess objectively the effects of buffered saline solutions on
nasal patency. Talbot and others have noted that in
patients with congestive rhinitis there are some subjective improvements in nasal patency with topical nasal
saline irrigation; however, there is little objective data
to support this finding.1,12-14
In this study, buffered saline solutions had a minimal effect on nasal cross-sectional area and nasal patency. Using acoustic rhinometry, it was found that 3%
buffered hypertonic saline led to decreased MCA1 and
MCA2 values in 7 out of 22 subjects (32%). Similarly,
buffered normal saline decreased nasal cavity crosssectional area in 6 out of 22 subjects (27%). These
changes, however, were small in aggregate and of uncertain clinical significance. A study by Baraniuk et al
found that hypertonic nasal irrigation reduced nasal
airspace volume and caused irritation.15 They suggested that hypertonic saline increased nasal secretion
production, causing negligible changes in nasal airspace volume while producing a significant increase in
the perception of rhinorrhea and nasal blockage.15
Potential sources of error in this study could come
from saccharine clearance times and acoustic rhinometry measurements. Saccharine clearance times are dependent upon the investigator’s appropriate placement
of the saccharine within the subject’s nose and the
subject’s adherence to instructions and perception of a
sweet taste. This study minimized potential bias and
variability by having only one investigator perform
experiments on all subjects, blinding both the investigator and subjects to the content of the solutions, and
observing the subjects until completion of the clearance
trial. Soane et al found the nasal cycle to have marked
effects on the mucociliary clearance patterns of the
Downloaded from oto.sagepub.com at Harvard University on February 27, 2013
Otolaryngology–
Head and Neck Surgery
November 2004
682 KEOJAMPA et al
nose.7 The clearance times determined in their study
showed a statistically significant difference between the
two nasal passages during the morning peak of the
nasal cycle, with the decongested side clearing more
rapidly than the congested side. These variances could
affect controlled studies on mucociliary clearance. In
order to compensate for the nasal cycle and other physiological variances, a subject’s measurements were
only compared after saline irrigation with his or her
own control measurements for that day and same nasal
cavity side.8,9
Several factors limit the accuracy of acoustic rhinometry measurements. The most widely recognized
problem with acoustic-pulse analysis is the inability to
measure accurately beyond narrow apertures.16 Furthermore, sound loss between the nostril and the acoustic probe and to the paranasal sinuses could negatively
affect the accuracy of acoustic rhinometry measurements of more distal segments.16 Sound loss was minimized by using a thin layer of gel as an acoustic seal
and closely fitting the probe to the nostril; measurements were repeated so that the results were reproducible.
A final limitation of this study is that the effects of
buffered saline solutions were examined in asymptomatic patients. For this reason, subjective data on perceived nasal obstruction could not be obtained. Future
studies could include symptomatic patients and a subjective component. In a symptomatic population, the
changes in nasal patency and mucociliary clearance
may be more pronounced, allowing for better discrimination of results. The significance of changes in nasal
airway dimension could then be correlated with
changes in perceived nasal obstruction.
CONCLUSIONS
In this study of asymptomatic subjects, both buffered hypertonic and buffered normal saline nasal spray
significantly improved saccharine clearance times without affecting nasal airway patency. Buffered hypertonic
saline affected saccharine clearance times to a greater
degree than buffered normal saline. Further study in
symptomatic patients is necessary before a specific
concentration of saline may be considered superior to
another.
The authors wish to acknowledge Cheryl Langford for her
cheerful editorial assistance.
REFERENCES
1. Talbot AR, Herr TM, Parsons D. Mucociliary clearance and
buffered hypertonic saline. Laryngoscope 1997;107:500-3.
(Grade A).
2. Cakmak O, Celik H, Ergin T, et al. Accuracy of acoustic rhinometry measurements. Laryngoscope 2001;111:587-94. (Grade
B).
3. Cakmak O, Coskun M, Celik H, et al. Value of acoustic rhinometry for measuring nasal valve area. Laryngoscope 2003;113:
295-302. (Grade B).
4. Hilberg O, Jensen FT, Pederson OF. Nasal airway geometry:
comparison between acoustic reflections and magnetic resonance
scanning. J Appl Physiol 1993;l75:2811-9. (Grade B).
5. Min YG, Jan YJ. Measurements of cross-sectional area of nasal
cavity by acoustic rhinometry and computed tomography. Arch
Otolaryngol Head Neck Surg 1997;123:401-5. (Grade B).
6. Stanley P, MacWilliam L, Greenstone M, et al. Efficacy of a
saccharin test for screening to detect abnormal mucociliary clearance. Laryngoscope 1992;102:117-20. (Grade A).
7. Soane RJ, Carney AS, Jones NS, et al. The effect of the nasal
cycle of mucociliary clearance. Clin Otolaryngol 2001;26:9-15.
(Grade B).
8. Littlejohn MC, Stiemberg CM, Hokanson JA, et al. The relationship between the nasal cycle and mucociliary clearance. Laryngoscope 1992;102:117-20. (Grade B).
9. Robinson M, Hemming AL, Regnis JA, et al. Effect of increasing
doses of hypertonic saline on mucociliary clearance in patients
with cystic fibrosis. Thorax 1997;52:900-3. (Grade A).
10. Proctor DF. The mucociliary system. In: Proctor DF, Andersen I,
editors. The Nose: Upper Airway Physiology and the Atmospheric Environment. New York: Elsevier Biomedical Press;
1982. p. 245.(Grade B).
11. Boek WM, Keles N, Graamans K, et al. Physiologic and hypertonic saline solutions impair ciliary activity in vitro. Laryngoscope 1999;109:396-9. (Grade B).
12. Jose J, Ell SR. The association of subjective nasal patency with
peak inspiratory nasal flow in a large healthy population. Clin
Otolaryngol 2003;28:352-4. (Grade B).
13. Jones AS, Viani L, Phillips D, et al. The objective assessment of
nasal patency. Clin Otolaryngol 1991;16:206-11. (Grade B).
14. Panagou P, Loukides S, Tsipra S, et al. The evaluation of nasal
patency: comparison of patient and clinician assessments with
rhinomanometry. Acta Otolaryngol (Stockh) 1998;118:847-51.
(Grade B).
15. Baraniuk, JN ,Ali M, Naranch K. Hypertonic saline nasal provocation and acoustic rhinometry. Clin Exp Allergy 2002;32:54350. (Grade A).
16. Hilberg O, Jackson AC, Swift DL, et al. Acoustic rhinometry:
evaluation of nasal cavity geometry by acoustic rhinometry.
J Appl Physiol 1989;66:295-303. (Grade D).
Downloaded from oto.sagepub.com at Harvard University on February 27, 2013