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Facial Plastic Surgery : FPS Jun 2024Assessing patients with complaints of nasal obstruction has traditionally been done by evaluation of the nasal airway looking for fixed or dynamic obstructive locations...
Assessing patients with complaints of nasal obstruction has traditionally been done by evaluation of the nasal airway looking for fixed or dynamic obstructive locations that could impair nasal airflow. Not infrequently, however, symptoms of nasal obstruction do not match the clinical examination of the nasal airway. Addressing this subset of patients may be a challenge to the surgeon. Evaluation of patients with symptoms of nasal obstruction should include a combination of a patient-reported assessment of nasal breathing and at least one objective method for measuring nasal airflow or nasal airway resistance or dimensions. This will allow distinction between patients with symptoms of nasal obstruction and low airflow or high nasal airway resistance and patients with similar symptoms but whose objective evaluation demonstrates normal nasal airflow or normal airway dimensions or resistance. Patients with low nasal airflow or high nasal airway resistance will require treatment to increase nasal airflow as a necessary step to improve symptoms, whereas patients with normal nasal airflow or nasal airway resistance will require a multidimensional assessment looking for less obvious causes of impaired nasal breathing sensation.
Topics: Humans; Nasal Obstruction; Airway Resistance; Algorithms; Rhinomanometry
PubMed: 38301716
DOI: 10.1055/s-0044-1779483 -
Journal of Applied Physiology... Oct 1999The interrupter technique is used to determine airway and tissue resistance. Their accuracy is influenced by the technical properties of the interrupter device and the...
The interrupter technique is used to determine airway and tissue resistance. Their accuracy is influenced by the technical properties of the interrupter device and the compliance of the respiratory system. We investigated the influence of valve characteristics and respiratory system compliance on the accuracy of determining airway and tissue resistance by means of a computer simulation. With decreasing compliance we found increasing errors in both airway and tissue resistance determination of up to 34 and 71%, respectively. On this basis we developed a new occlusion valve, with special emphasis on rapid closing time and tightness in the closed state to improve the accuracy of resistance determination. The newly developed occlusion device greatly improves the accuracy of airway and tissue resistance determination. We conclude that respiratory system compliance is a limiting factor for the accuracy of the interrupter technique. To apply the interrupter technique in patients with extremely low respiratory system compliances, we need sophisticated technical devices.
Topics: Airway Resistance; Compliance; Equipment Design; Equipment and Supplies; Humans; Models, Biological; Respiratory Physiological Phenomena
PubMed: 10517790
DOI: 10.1152/jappl.1999.87.4.1546 -
International Archives of Allergy and... 2010
Topics: Airway Resistance; Animals; Female; Mice; Mice, Inbred BALB C; Nose; Respiratory Function Tests
PubMed: 19786807
DOI: 10.1159/000242364 -
The Tokai Journal of Experimental and... Mar 1998Although airway resistance (R) is an important parameter of the pulmonary condition, its determination during mechanical ventilation is not easy. Most physicians...
Although airway resistance (R) is an important parameter of the pulmonary condition, its determination during mechanical ventilation is not easy. Most physicians estimate R from peak airway pressure during mechanical ventilation. We assessed the relationship between R and peak airway pressure by a computer simulation. The time course of airway pressure (Ptr) during mechanical ventilation was calculated from the airway pressure at end-inspiration and respiratory flow, allowing for the buffering effect of the dead space. The parameters for computer simulation were obtained from 5 paralyzed and mechanically ventilated dogs. The predicted Ptr curve was a function of airway resistance. Since R was not directly determined by the animal experiments, we determined R by using the Ptr curve most closely approximating the original Ptr curve as the true R. The R-peak tracheal pressure relationship predicted by computer simulation showed that the peak airway pressure increased almost linearly with increases in R. However, in computer simulation, when R was increased 10-fold from the value at airway relaxation, the peak airway pressure increased only 6-fold from the corresponding value. We conclude that peak airway pressure is a relatively insensitive parameter for the estimation of airway constriction during mechanical ventilation.
Topics: Airway Resistance; Animals; Dogs; Pulmonary Ventilation
PubMed: 9972533
DOI: No ID Found -
Otolaryngology--head and Neck Surgery :... Oct 1990Measurement of nasal airway resistance is becoming a common clinical technique. Accurate definition of the normal range of airflow is critical for maximal usefulness of...
Measurement of nasal airway resistance is becoming a common clinical technique. Accurate definition of the normal range of airflow is critical for maximal usefulness of this technique. Since typical nasal size and shape vary greatly with ethnic background, different norms for different ethnic groups may be appropriate. Nasal airway flow and resistance and external nasal size and shape were measured in 130 asymptomatic subjects (52 black, 56 white, and 22 Hispanic). Nasal length, width, columellar length, and nasolabial angle were similar for whites and Hispanics, but both groups differed significantly from blacks--even when changes attributable to biologic aging were factored out. In spite of these differences, there was no significant difference in any nasal airflow or resistance parameter among groups, suggesting that currently used airflow and resistance standards are valid for these three different ethnic groups.
Topics: Airway Resistance; Anthropometry; Black People; Female; Hispanic or Latino; Humans; Male; Nose; Reference Values; White People
PubMed: 2123319
DOI: 10.1177/019459989010300413 -
The Laryngoscope Jan 2022Nasal diseases are among the main motives for the early discontinuation of continuous positive airway pressure therapy and for long-term therapeutic compliance with... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
Nasal diseases are among the main motives for the early discontinuation of continuous positive airway pressure therapy and for long-term therapeutic compliance with mandibular advancement device. Although our clinical experience leads us to the belief that recumbency impacts nasal airflow in some patient populations, there is no consensus regarding the magnitude of this effect and the specific group of patients who are the most affected by this condition. In this study, we conducted a meta-analysis to assess the effect of the recumbent position on nasal resistance and nasal airflow.
REVIEW METHODS
PubMed (Medline), Cochrane Library, EMBASE, Scopus, and SciELO databases were checked for relevant studies by two members of the YO-IFOS study group. The two authors extracted the data. The main outcome was expressed as the difference between nasal resistance and nasal airflow before and after recumbency.
RESULTS
Nine studies with a total population of 291 individuals were included in the meta-analysis for nasal resistance after recumbency. We found a statistically significant difference in nasal airway resistance of -0.18 Pa sec/cm as compared to before and after recumbency through rhinomanometry (RMM) analysis. A subgroup analysis revealed a variation of -0.20 Pa sec/cm for patients with snoring or sleep apnea and - 0.10 Pa sec/cm for healthy individuals. Regarding nasal airflow measured with RMM, three studies (n = 32) in asymptomatic controls revealed a statistically significant difference of 47.33 ml/sec.
CONCLUSIONS
Recumbency increases nasal resistance and diminishes nasal airflow. This finding is of utmost importance in snorers and sleep apnea patients. Laryngoscope, 132:6-16, 2022.
Topics: Airway Resistance; Humans; Nasal Cavity; Supine Position
PubMed: 33720430
DOI: 10.1002/lary.29509 -
Artificial Cells, Blood Substitutes,... 1994To evaluate the effect of the physical properties of density and viscosity on airway resistance, three perfluorochemical fluids (PFCs) were used: FC-75, Liquivent, and... (Comparative Study)
Comparative Study
To evaluate the effect of the physical properties of density and viscosity on airway resistance, three perfluorochemical fluids (PFCs) were used: FC-75, Liquivent, and APF-140. Using two different endotracheal tubes (ETT) (3.0mm ID and 4.0mm internal diameter (ID)), the three fluids were studied at steady state flow conditions over a range that approximated peak flow required for liquid ventilation of neonatal lambs (0.005-0.02 l/sec). The slope of airway resistance (Raw)-flow curves and absolute values of Raw for the 3 PFC liquids were higher for the 3.0 ETT compared to the 4.0 ETT. The 3.0 ETT demonstrated resistance changes that were dependent on flow, density and viscosity. The 4.0 ETT showed a resistance-flow relationship that was relatively less dependent on flow, density and viscosity.
Topics: Airway Resistance; Animals; Animals, Newborn; Chemical Phenomena; Chemistry, Physical; Fluorocarbons; Intubation, Intratracheal; Sheep
PubMed: 7849950
DOI: 10.3109/10731199409138843 -
Respiratory Physiology & Neurobiology Jan 2022Few studies have examined the influence of different water depths on the airway impedance measured by forced oscillation technique in healthy adults.
INTRODUCTION
Few studies have examined the influence of different water depths on the airway impedance measured by forced oscillation technique in healthy adults.
METHODS
Eleven healthy men (23.2 ± 1.5 years old) participated in this study. We measured the respiratory impedance assessed with the resistance at frequency of 5 Hz and 20 Hz, the reactance at frequency of 5 Hz, and frequency of resonance. To compare the influence of water depths, we carried out one dryland (DL) and two water level conditions: clavicle level (CL) and xiphoid appendix level (XA).
RESULTS
The respiratory resistance at frequency of 5 Hz was higher in CL and XA than DL, and at 20 Hz was significantly higher in CL than DL. The respiratory reactance at 5 Hz was lower in CL and XA than DL, and frequency of resonance was higher in CL and XA than DL.
CONCLUSION
These results suggested that water immersion above xiphoid appendix level increase airway resistance.
Topics: Adult; Airway Resistance; Electric Impedance; Humans; Immersion; Male; Respiratory Physiological Phenomena; Spirometry; Water; Young Adult
PubMed: 34455088
DOI: 10.1016/j.resp.2021.103779 -
The European Respiratory Journal Aug 1996Specific airway resistance (sRaw) measured by body plethysmography has been shown to decrease markedly with decreasing breathing frequency when the inspired air is not...
Specific airway resistance (sRaw) measured by body plethysmography has been shown to decrease markedly with decreasing breathing frequency when the inspired air is not conditioned to body temperature, atmospheric pressure and saturation with water vapour (BTPS). The phenomenon has been attributed to noninstantaneous gas warming and wetting in the airways. The aim of this investigation was to assess whether the phenomenon was also present in a commercialized plethysmograph featuring an "electronic BTPS correction". Airway resistance (Raw) and sRaw were measured in 15 healthy subjects at six breathing frequencies ranging 0.25-3 Hz, using a constant volume plethysmograph in which a correction for non-BTPS gas conditions was applied by electronically flattening the box pressure-airway flow loop (Jaeger Masterscreen Body, version 4.0). The temperature and water vapour saturations in the box averaged 26.5 +/- 1.3 degrees C and 59 +/- 6%, respectively. Raw and sRaw exhibited a clear positive frequency dependence in all but one subject. From 0.25 to 3 Hz Raw increased from (mean+/-SD) 0.62 +/- 0.55 to 1.71 +/- 0.76 hPa x s x L-1 (p<0.001), and sRaw from 2.34 +/- 1.90 to 7.55 +/- 3.08 hPa x s (p<0.001). The data are consistent with a simple model, in which gas conditioning in the airways and external dead space occurred with a time constant of 0.39 s. We conclude that the electronic BTPS correction of the instrument was inadequate, probably because it is assumed that gas conditioning in the airways is instantaneous. We recommend that, with similar instruments, airway resistance be measured using as high a panting frequency as feasible.
Topics: Adult; Airway Resistance; Equipment Safety; Female; Humans; Male; Middle Aged; Plethysmography; Pulmonary Gas Exchange
PubMed: 8866604
DOI: 10.1183/09031936.96.09081747 -
Rhinology Mar 1996Two methods for decongestion of the nasal mucosa were compared, a conventional nasal spray and a bellows device, the reproducibility of rhinomanometric measurements... (Comparative Study)
Comparative Study
Two methods for decongestion of the nasal mucosa were compared, a conventional nasal spray and a bellows device, the reproducibility of rhinomanometric measurements being investigated in both cases. Nasal airway resistance (NAR) was measured in 18 patients (during late autumn) before, 10 min, and 20 min after decongestion with an oxymetazoline solution from a bellows device, and the measurements were repeated one week later. About three months later (during spring) the measurements were repeated in the same 18 patients, but with a xylometazoline nasal spray being used for decongestion. With neither method were any differences in NAR found between 10 and 20 min after decongestion, or between any of the values (before or after decongestion) and the respective values obtained after one week. The NAR values of the undecongested total nose and the wider nose cavity were significantly higher during the late autumn than during the spring, as were also a few values after decongestion. We found no evidence that the bellows method is superior to the spray method in reducing NAR.
Topics: Administration, Intranasal; Adult; Airway Resistance; Female; Humans; Imidazoles; Male; Manometry; Middle Aged; Nasal Decongestants; Nasal Obstruction; Nebulizers and Vaporizers; Oxymetazoline; Reproducibility of Results; Time Factors
PubMed: 8739865
DOI: No ID Found