Evaluation of the effect of localized skin cooling on nasal airway volume by acoustic rhinometry

2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group

The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems; head-up cardiopulmonary resuscitation; early coronary angiography after return of spontaneous circulation; cardiopulmonary resuscitation in the prone patient; cord management at birth for preterm and term infants; devices for administering positive-pressure ventilation at birth; family presence during neonatal resuscitation; self-directed, digitally based basic life support education and training in adults and children; coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest; and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.

2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems; head-up cardiopulmonary resuscitation; early coronary angiography after return of spontaneous circulation; cardiopulmonary resuscitation in the prone patient; cord management at birth for preterm and term infants; devices for administering positive-pressure ventilation at birth; family presence during neonatal resuscitation; self-directed, digitally based basic life support education and training in adults and children; coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest; and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.

Use of Cryotherapy for Managing Epistaxis in the First Aid Setting: A Scoping Review

Epistaxis, or nosebleed, is bleeding from the nostril(s), nasal cavity, or nasopharynx. Anterior nasal bleeding is the most common location for spontaneous nontraumatic epistaxis and is commonly treated with manual compression to the nasal alae. Cryotherapy is also routinely recommended in conjunction with manual compression in the first aid and ED setting. We performed a scoping review on behalf of the International Liaison Committee on Resuscitation First Aid Task Force guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). We searched Embase, Cochrane, and PubMed databases for published studies, without date restrictions, and we searched the gray literature using Google.com and Google Scholar. The websites of selected resuscitation councils were searched for guidelines relating to the management of epistaxis. References from included studies were hand-searched. Our published and gray literature search identified 1255 and 61,315 records, respectively. After removing duplicates and following selection criteria, we included 21 records from the published literature and 11 records from the gray literature. Our scoping review found that most of the published studies and website documents focused on managing nontraumatic epistaxis in the first aid setting. They provide recommendations for the use of cryotherapy based on expert opinion or indirect evidence extrapolated from cryotherapy-associated changes in nasal submucosal temperature, nasal blood flow, and nasal blood volume in healthy subjects (three studies). We did not identify any prospective, randomized trials comparing the efficacy of cryotherapy as an intervention for nontraumatic epistaxis in the first aid setting. The limited literature identified in this scoping review does not support the development of a systematic review but highlights the need for future research to better understand the role of cryotherapy in the first aid setting.

Effects of Vasoactive Agents and their Antagonists Measured by Acoustic Rhinometry

The purpose of this study was to assess the effects of a agonists on the human nasal mucosa. Volumetric changes in the nasal cavity after application of phenylephrine (PNL), oxymetazoline (OMZ), and epinephrine (EPR) were investigated using acoustic rhinometry. The reactions of the nasal mucosa were extremely modified after pretreatment by α1 and α2 antagonists, phenoxybenzamine (POB) and yohimbine (YOH), and local anesthetic, xylocaine (XLC). Decongestion of the nasal mucosa evoked by α stimulants was considered to originate mainly from the direct activation of α1 receptors. Decongestion of the middle and posterior parts began later than the anterior part and was more gradual because of the time necessary to transport the drug particles to the posterior areas. Contralateral volume changes were probably controlled by the afferent signals from the ipsilateral side of the nose.

Reproducibility of Acoustic Rhinometric Measurements

The purpose of this study is to evaluate the reproducibility of acoustic rhinometric measurements obtained by means of a technique that avoids distortion of the compliant nasal vestibule. Subjects with noses untreated by decongestant were tested every minute for 6 consecutive minutes (576 area-distance curves–A-D curves), every 30 minutes for 6 consecutive hours (672 A-D curves), every day at 9 AM for 5 consecutive days (1200 A-D curves) and every Monday morning for 5 consecutive weeks (1200 A-D curves). The coefficient of variation found for the total minimum cross-sectional area (MCA) and total nasal volume (NV) increased with duration of the time interval between test and retest from 5% to 17% and from 4% to 9%, respectively. Variation of total MCA (combined right and left) and total NV (combined right and left) was smaller than variation of unilateral MCA or NV. Despite the dynamic nature of the nose, a standardized acoustic rhinometric technique can obtain acceptable results from subjects acting as their own controls in nasal physiological research and in clinical assessments.

Evaluation of the effect of nasal dorsal skin cooling on nasal mucosa by acoustic rhinometry

BACKGROUND

The use of cold nasal packs on the nose and nape of the neck is currently recommended for patients with epistaxis as this is thought to induce reflex nasal vasoconstriction, which decreases the bleeding. There have been a few investigations on the effect of cold compress application to the nose, but none of these focused specifically on nasal cooling of the skin of the nose.

METHODS

Acoustic rhinometry was performed to obtain baseline measurements. Nasal dorsal skin was then cooled with two ice packs that were held on the left and right side of the nose for a total of 10 minutes by the subjects. The rhinometry measurements were taken at the time of initial application (baseline), and after 5 and 10 minutes of ice pack application.

RESULTS

Comparisons of the first and second minimal cross-sectional area values, and total nasal cavity volume measurements revealed no statistical differences.

CONCLUSION

The results of this study indicate that one should be sceptical about the efficiency of cold compress application, which is frequently used in clinical practice in cases with epistaxis.

Modern indoor climate research in Denmark from 1962 to the early 1990s: an eyewitness report

Modern, holistic indoor climate research started with the formation of an interdisciplinary 'Indoor Climate Research Group' in 1962 at the Institute of Hygiene, University of Aarhus, Denmark. After some years, other groups started similar research in Denmark and Sweden, and later - after the First International Indoor Air Symposium in Copenhagen 1978--this research spread to many countries and today it is carried out globally by probably 2000 scientists. This paper recounts the history of Danish indoor climate research, focusing on the three decades from the early 1960s to the founding of the Indoor Air journal in 1991. The aim of this paper is to summarize what was learned in those earlier years and to call to the attention of researchers in this area the need of multidisciplinary research, mingling epidemiological fact-finding field studies with climate chamber studies and laboratory investigations.

PRACTICAL IMPLICATIONS

The review may be of interest to indoor climate researchers who want to know more about the early development of research on this multidisciplinary subject, as it emerged in a small country that undertook pioneering studies.

Transnasal cooling: a Pandora's box of transnasal patho-physiology

The innovative concept of transnasal evaporative cooling for therapeutic hypothermia in cardio-pulmonary-cerebro-resuscitation has therapeutic implications with evidence of rapid and selective brain cooling; however, this author wants to elicit that this concept may hold answers for many physiological phenomena which have not been explored or completely understood up till now. To affirm the physiological role of transnasal cooling, the innovative non-invasive brain temperature monitoring can help the investigators to explore and understand the following transnasal pathophysiological phenomena: (1) understanding correlation of brain temperature and sinus headache secondary to nasal blockade, (2) exploring the therapeutic role of nasal oxygen for prevention of delirium in intubated patients, (3) realizing the impact of controlled enclosed environments on the mood and affect of the inhabitants, (4) understanding the etio-pathogenesis of claustrophobia after excluding the confounding factors of morbid obesity, severe cardiopulmonary disease and incapacitating musculoskeletal diseases, (5) exploring the anthropological role of male pattern of moustache, beard and hair loss, and (6) possible development of a coolant moustache as proposed by the author. In summary, transnasal pathophysiology offers many promising lines of fruitful research to explore the non-olfactory physiological functions of nose in human beings.

Physiological change in nasal patency in response to changes in posture, temperature, and humidity measured by acoustic rhinometry

BACKGROUND

Acoustic rhinometry has been used to assess nasal patency and to calculate nasal cavity volume. This study used acoustic rhinometry to assess changes in nasal patency after alterations in posture, unilateral mechanical obstruction, temperature, and humidity.

METHODS

Eight healthy adult volunteer subjects underwent acoustic rhinometry during the following conditions: (1) sitting position (control), (2) supine position, (3) left lateral recumbent position, (4) nostril unilaterally mechanically blocked, (5) ice pack on neck, (6) drinking cold water, (7) drinking hot water, (8) nasal nebulizer, and (9) oxymetazoline decongestant.

RESULTS

Two distinct patterns emerged based on the total nasal cavity volumes in response to the decongestant. Subjects with initial unilateral nasal cavity volumes near the mean had an expected increase in total volume after the topical decongestant administration. There were two subjects with initial volumes of 1 SD above the mean that had a paradoxical decrease in total volume in response to the decongestant. In all subjects, there was a significant decrease in the volume of each of the nasal cavities in response to ingestion of hot water at 1 minute. There was a significant decrease in the volume of the smaller of the two nasal cavities in response to nebulizer treatment and hot water ingestion at 5 minutes. Total nasal cavity volume changes were not significant for any of the variables.

CONCLUSION

Changes in nasal cavity volumes were detected by acoustic rhinometry after alterations in posture, unilateral mechanical obstruction, temperature, and humidity. Nebulizer treatment and hot water ingestion caused a significant decrease in nasal volume. The nose of a healthy patient was able to adapt to environmental and physiological changes to maintain a consistent total nasal volume within 15 minutes.

Acoustic rhinometry: validation by three-dimensionally reconstructed computer tomographic scans

The aim of the present study was a validation of acoustic rhinometry (AR) by computed tomography (CT). Six healthy subjects were examined by CT and AR. The CT data were processed in a computer program (AutoCAD), and a virtual three-dimensional model of each nasal cavity was constructed. This model permitted an individual prediction of the center line of the sound wave propagation through the air volume of the nasal cavity with the cross-sectional areas oriented perpendicularly to this line. The area-distance curves derived from AR and CT were compared. Linear regression analysis revealed a reasonable agreement of AR and CT in the anterior nose below a mean of 6 cm distance from the nostrils [r = 0.839, P < 0.01, m = 1.123, b = -0.113 (AR = m x CT + b)]. The measuring accuracy using CT as gold standard revealed a mean error at the nasal valve of <0.01 cm(2) (4.52%) and at the nasal isthmus of 0.02 cm(2) (1. 87%). Beyond 6 cm, the correlation decreased (r = 0.419), and overestimation of the true area occurred (>100%). In conclusion, the measurements were reasonably accurate for diagnostic use up to the turbinate head region. Certain factors induce an overestimation of the true areas beyond this region. However, these factors are constant and reproducible in a single subject, and intraindividual comparative measurements are possible beyond the turbinate head region.

The effect of cold water immersion on the nasal mucosa

The response of the nasal mucosa to cold water immersion is not well known. We have attempted to document this response in normal individuals. Seventeen individuals with no history of nasal disease or allergy were studied. All subjects were asked to perform sustained cold water (15 degrees C) immersion of their hand and forearm on the side of the obstructed nostril for a period of 5 min. The nasal cross-sectional area was measured on both sides of the nose using an acoustic rhinometer. The individuals were then rested for at least 30 min and the test repeated with immersion of the opposite hand. There was a significant fall in nasal cross-sectional area on the side of immersion (median change = 0.32 cm2, P = 0.0003) with a significant rise in nasal cross-sectional area on the none test side (median change = 0.35 cm2, P = 0.0003). There were no significant differences between these results and those obtained by immersion on the opposite side. The results indicate that cold water immersion produces nasal obstruction and that both afferent and efferent arms of this reflex are side-specific.

Histamine H1 receptor and reactivity of the nasal mucosa in sensitized guinea pigs

OBJECTIVE

Nasal Hypersensitivity to histamine is higher in allergic patients than that in normal control, suggesting that affinity and/or density of H1 receptors in nasal mucosa may be increased in patients with allergic rhinitis. The purpose in this study is to examine the correlation between the hyperresponsiveness and number of histamine H1 receptors in guinea pig nasal mucosa.

METHODS

Guinea pigs were sensitized by DNP-Ascaris antigen. To block histamine H1 receptors, ketotifen was used and the number of receptors was counted by receptor binding assay technique. These data were compared with nasal airway volume (VOL) assessed by acoustic rhinometry of the same animals to know whether the number of H1 receptors is correlated to the nasal responsiveness to the antigen, or not. Eighty animals were divided into five groups which are composed of nonsensitized and sensitized group pretreated with saline, 0.1, 1.0 and 10 mg/kg of ketotifen, respectively.

RESULTS

The number of H1 receptors (Bmax) was significantly increased in sensitized group compared with that in control. It decreased dose dependently by pretreatment of ketotifen. The percent change of VOL showed - 31.1 +/- 4.1% at 10 min and - 42.9 +/- 4.1% at 30 min after antigen challenge in sensitized animals. This was dose dependently inhibited by ketotifen. There was a highly inverse correlation between VOL and Bmax (r = -0.708, P< 0.0001).

CONCLUSION

These results suggest that sensitization increases the number of histamine H1 receptor, and that increased number of H1 receptor in nasal mucosa in sensitized guinea pigs may be one of the causes of nasal hyperresponsiveness to antigen.

Acoustic rhinometry evaluation of nasal response to histamine and antigen in guinea pigs

The effects of antigen and histamine on the changes of nasal passage patency in 112 guinea pigs with or without allergic rhinitis were evaluated by acoustic rhinometry. The percent change of volume from the nostril to 2 cm into the nasal cavity showed significant reduction of 31.10 +/- 4.11% at 10 minutes and 31.10 +/- 4.11% at 30 minutes after antigen challenge in sensitized guinea pigs. The pretreatment with ketotifen, an H1-histamine receptor antagonist as well as mast cell stabilizing drug, blocked dose-dependently the effects of antigen on those changes in volume. Furthermore, instillation of 10(4) micrograms/mL histamine reduced significantly nasal passage patency to 33.77 +/- 4.63% at 10 minutes and 42.76 +/- 3.32% at 30 minutes after challenge compared with that before challenge and ketotifen inhibited the effects of histamine, which indicated that histamine is an important mediator of allergic upper airway responses in guinea pigs. These results show that acoustic rhinometry is a useful technique to assess the nasal blockade in allergic guinea pigs.

The effect of leukotriene D4 on the patency of nasal passage in the guinea pig

We investigated the effect of leukotriene D4(LTD4) on the patency of the nasal passage in nonsensitized and sensitized guinea pigs (GPs). The change in nasal patency was measured by acoustic rhinomanometry (AR). The change of volume from the nostril to 2 cm into the nasal cavity showed significant reduction at 30 minutes and 6 hours after instillation of LTD4 in nonsensitized GPs. These findings were also seen in nonsensitized and sensitized GPs with systemic administration of carboxyl cellulose. However, neither nonsensitized nor sensitized GP with systemic administration of benzopyren hemihydrate(ONO-1078) showed any changes in nasal patency. These results indicated that the LT was a potent medication to induce nasal obstruction of late reaction in GP.

Effects of nasal-airway volume and body temperature on intranasal chemosensitivity

Interrelations between intranasal detection sensitivity for odor (H2S) and pain (CO2), nasal-airway volume (acoustic rhinometry), and body temperature were studied in young, healthy men across the diurnal cycle. The results showed a weak but statistically significant negative correlation between nasal volume and odor threshold and a weak but positive correlation between body temperature and odor threshold.

Evaluation of the nasal cavity by acoustic rhinometry in normal and allergic subjects

With acoustic rhinometry, one can detect a difference in response to a topical decongestant between normal and allergic subjects at the minimal cross-sectional area. The minimal cross-sectional area corresponds in most cases to the anterior end of the inferior turbinate or the first valley, which occurs after the nose piece of the acoustic rhinometer on the acoustic rhinometry graph. Allergic patients typically have an increase in nasal mucosal swelling, which leads to a decrease in the nasal volume and area and, subsequently, to an increase in congestion. In this study acoustic rhinometry was used to test normal and allergic subjects before and after the application of a topical decongestant (1% phenylephrine (Neo-Synephrine)). Symptoms were measured by a five-point scale. Results showed that increasing symptom scores demonstrated a trend toward being related to decreasing area as measured at the minimal cross-sectional area or nasal valve. The average total percent change at the minimal cross-sectional area was calculated for both groups and compared. The normal subjects had an average total percent area change at the minimal cross-sectional area of 15.6% ± 14.8%, and the allergic subjects had a percent change of 24.6% ± 20.8%. This represents a significant difference between the normal and allergic subjects in response to the topical decongestant at the minimal cross-sectional area ( p = 0.04). However, the average total percent change was not significantly different between the two groups at the second and third valleys. At the second valley, the normal subjects had a percent change of 40% ± 17.5%, and the allergic subjects had a percent change of 36% ± 18.5%. At the third valley, the normal subjects had a percent change of 35% ± 15.4%, and the allergic subjects had a percent change of 32% ± 20.6% ( p = 0.4 and 0.5, respectively). The total area was calculated by adding measurements from both right and left nasal cavities for each subject in an attempt to control the effect of the nasal cycle. Acoustic rhinometry makes it possible to detect a trend in the relationship between either a decrease in area at the minimal cross-sectional area or a decrease in the total volume from 0 to 7 cm into the nasal cavity and congestion. A statistically significant difference between normal and allergic subjects in their response to a topical decongestant at the minimal cross-sectional area was detected by acoustic rhinometry at the nasal valve.

Evaluation of nasal passage patency after antigen and histamine challenge in guinea pigs by acoustic rhinometry

We investigated the effects of antigen and histamine on the nasal passage patency in guinea pigs with or without nasal allergy. The change of nasal patency was measured by acoustic rhinometry and nasal airway resistance. Acoustic reflections have been used in adult humans to determine nasal cavity dimensions in terms of cross-sectional areas as a function of the distance from the nostril. In order to measure nasal cavity dimensions in guinea pigs, we modified equipment for use in humans by decreasing sound tube dimensions, increasing sampling frequency, and applying a special nosepiece. The percent change of volume, minimum cross-sectional area, and nasal airway resistance showed the largest changes at 10 minutes after antigen challenge in sensitized guinea pigs. There was a significant correlation between the individual percent change of nasal airway resistance and volume or minimum cross-sectional area. Histamine, 10(2) to 10(5) micrograms/mL, caused a dose-dependent reduction in percent change of volume in the challenged side of nonsensitized guinea pigs, but not in the opposite side. These results indicate that the noninvasive acoustic reflections technique is useful in small experimental animals, especially to assess the effect of nasal cavity dimensions after the challenge of antigen or nonspecific stimuli.

Acoustic rhinometry in the study of the acute nasal allergic response

Acoustic rhinometry is a recently developed method for the objective assessment of nasal patency. In this study, acoustic rhinometry was used to measure changes in nasal cavity dimensions in the immediate response to nasal allergen challenge in eight pollen-sensitive subjects. Acoustic rhinometric changes were compared with subjective symptoms, as well as histamine in nasal secretions, cytology of nasal mucosal scrapings, and changes in olfactory function. A significantly greater decrease in nasal airway caliber occurred following allergen challenge as compared to buffer diluent challenge in the same individuals (70% +/- 7% versus 22% +/- 5%). During an allergic response, a strong correlation was found between the minimum cross-sectional area and the volume of the nasal cavity measured by acoustic rhinometry (r = .9). However, no correlation was observed between nasal airway caliber and concomitant subjective congestion reported by the subjects. A modest decrease in olfactory function was seen following allergen challenge (3.1 +/- 1.4 fewer odors identified correctly out of 20; p = .08). However, the alterations of olfactory function did not correlate with changes in nasal patency. The results presented in this study demonstrate that acoustic rhinometry has great potential as a reproducible method for the objective assessment of nasal obstruction occurring in nasal allergen challenge studies.

Posture and nasal patency: evaluation by acoustic rhinometry

Nasal passage geometry was measured by acoustic rhinometry in 8 healthy medical students (5 males and 3 females, 21-29 years old; mean age 24 years) after 6 min in different postures of head and body. The minimum cross-sectional area (A-min) and volume between the nostril and 7 cm posteriorly were measured on both sides. When changing from sitting to horizontal the total airway dimension (i.e., the sum of A-min for the two sides) decreased by about 16% (Mean +/- SD = 0.19 +/- 0.14 cm2), and when standing up it increased by about 12% (0.14 +/- 0.13 cm2). A-min seemed more sensitive than volume to detecting postural changes. Including the variation between the cavities, the coefficient of variation (CV = SD/Mean) for area was 24.8 +/- 6.7 and for volume 22.4 +/- 6.4 for the 8 subjects. For the total nasal airway passage the corresponding figures were 12.9 +/- 3.9 and 10.9 +/- 5.5. These figures are considerably higher than for subjects measured only in the sitting position under comparable circumstances. In conclusion, our findings indicate a composite response of the nasal cavity mucosa to both systemic (hydrostatic) and local conditions, probably induced by vascular and cutaneous reflexes. These factors must be taken into account in studies of environmental, clinical, and pharmacological conditions.

Nasal reaction to changes in whole body temperature

The changes in nasal patency following a 1.5 degrees C decrease or increase in whole body temperature were measured in 8 healthy young males, during and after 30 min of immersion in a 15 degrees C cold or a 40 degrees C warm bath, breathing air at the same temperature, in a cross-over experimental design. The nasal reactions were traced by consecutive measurements of changes in nasal cavity volumes by acoustic rhinometry. Swelling of the mucosa during cooling and an almost maximal shrinkage of the mucosa during heating were indicated by respectively a decrease and an increase in nasal cavity volumes. The reactions were determined predominantly by the whole body thermal balance, but were also influenced by the temperature of the inhaled air, either enhanced, reduced or temporarily reversed. The greatest change occurred in the nasal cavity, left or right, which differed most from the final state at the beginning of exposure due to the actual state of nasal cycle.