Partitioning of respiratory flow resistance in man

Ferris, Benjamin G.; Mead, J.; Opie, L.H.

doi:10.1152/jappl.1964.19.4.653

Cited by 408 publications

(174 citation statements)

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“…31 The nasal passage contributes to approximately two-thirds of the upper airway resistance. 77 Any reduction in nasal airflow due to anatomic defects, such as nasal septal deviation or turbinate enlargement, can further increase this resistance, thereby increasing the likelihood of upper airway collapse during sleep and potentially worsening the severity of OSA. Additionally, anatomic defects can result in an increase in the required pressure during positive airway pressure therapy (eg, CPAP), the most commonly utilized treatment for this disorder.…”

Section: Supporting Textmentioning

confidence: 99%

Clinical Practice Guideline: Improving Nasal Form and Function after Rhinoplasty

Ishii

Tollefson

Basura

et al. 2017

Otolaryngol.--head neck surg.

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Objective. Rhinoplasty, a surgical procedure that alters the shape or appearance of the nose while preserving or enhancing the nasal airway, ranks among the most commonly performed cosmetic procedures in the United States, with >200,000 procedures reported in 2014. While it is difficult to calculate the exact economic burden incurred by rhinoplasty patients following surgery with or without complications, the average rhinoplasty procedure typically exceeds $4000. The costs incurred due to complications, infections, or revision surgery may include the cost of long-term antibiotics, hospitalization, or lost revenue from hours/days of missed work.The resultant psychological impact of rhinoplasty can also be significant. Furthermore, the health care burden from psychological pressures of nasal deformities/aesthetic shortcomings, surgical infections, surgical pain, side effects from antibiotics, and nasal packing materials must also be considered for these patients. Prior to this guideline, limited literature existed on standard care considerations for pre-and postsurgical management and for standard surgical practice to ensure optimal outcomes for patients undergoing rhinoplasty. The impetus for this guideline is to utilize current evidence-based medicine practices and data to build unanimity regarding the peri-and postoperative strategies to maximize patient safety and to optimize surgical results for patients.Purpose. The primary purpose of this guideline is to provide evidence-based recommendations for clinicians who either perform rhinoplasty or are involved in the care of a rhinoplasty candidate, as well as to optimize patient care, promote effective diagnosis and therapy, and reduce harmful or unnecessary variations in care. The target audience is any clinician or individual, in any setting, involved in the management of these patients. The target patient population is all patients aged ≥15 years. The guideline is intended to focus on knowledge gaps, practice variations, and clinical concerns associated with this surgical procedure; it is not intended to be a comprehensive reference for improving nasal form and function after rhinoplasty. Recommendations in this guideline concerning education and counseling to the patient are also intended to include the caregiver if the patient is <18 years of age.Action Statements. The Guideline Development Group made the following recommendations: (1) Clinicians should ask all patients seeking rhinoplasty about their motivations for surgery and their expectations for outcomes, should provide feedback on whether those expectations are a realistic goal of surgery, and should document this discussion in the medical record. (2) Clinicians should assess rhinoplasty candidates for comorbid conditions that could modify or contraindicate surgery, including obstructive sleep apnea, body dysmorphic disorder, bleeding disorders, or chronic use of topical vasoconstrictive intranasal drugs. (3) The surgeon, or the surgeon's designee, should evaluate the rhinoplasty candidate for...

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Section: Supporting Textmentioning

confidence: 99%

Clinical Practice Guideline: Improving Nasal Form and Function after Rhinoplasty

Ishii

Tollefson

Basura

et al. 2017

Otolaryngol.--head neck surg.

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“…There happens differences in the severity of the resistance in the airways depending on its localization as well [13]. The phasic airway response, occurring against the triggers like anxiety in healthy individuals, is generally thought to occur by the effects of upper airways (muscles of larynx, glottic aperature) more generally during expirium [17,20,21]. Ritz et al experimentally observed a total airway resistance against affective stimulants in healthy individuals only in the inspiratory section.8 However, in the experimental studies conducted afterwards, the inspiratory or the expiratory resistances in the airway that are created by affective stimulants could not have been proved to be superior to the other [19].…”

Section: Discussionmentioning

confidence: 99%

The effect of preoperative anxiety on the incidence of perioperative bronchospasm: a prospective observational study

Kocatürk¹,

Oğuz²

2017

Med-Science

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Independently from the chronic anxiety disorder, patients could feel nervousness and anxiety due to surgical stress during preoperative period. Preoperative anxiety could lead to various complications owing to autonomous nerve system activation. We targeted to examine the effects of preoperative anxiety on bronchospasm. In the study, 20-50 years old ASA I patient to be given elective endoscopic urologic operations were included. Totally 124 patients were evaluated during preoperative period. The patients were interviewed before the operation to determine their anxiety levels (Beck Anxiety Scale). Patients were grouped according to anxiety state. 58 anxious patients (Study Group) and 66 non-anxious (Control Group) were compared according to bronchospasm, wheezing, SpO2 paucity and ETCO2 extent. Incidence of bronchospasm and wheezing were found more in the patient group having preoperative anxiety (p<0.05). No meaningful correlation was found between the groups with regard to the changes in SpO2 and ETCO2. Various studies were conducted using emotion-induction techniques. However, they produced artificial stress and these results were not associated with any surgical procedures. Unlike all these studies, we showed natural clinical course of non-induced anxiety effects on all perioperative period. Our study demonstrated that anxiety prior to a general anesthesia and changes in the emotional state could create a risk for total respiratory resistance. These changes could arise as bronchospasm and wheezing during the perioperative period.

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“…Conversely, airway resistance in a turbulent V ' regimen is proportional to gas density. It is considered that UA is characterized by a fully turbulent or a transitional V ' [10]. Therefore, the contribution of gas Table 1.…”

Section: Discussionmentioning

confidence: 99%

Influence of gas density on simulated snoring

Liistro¹,

Veriter²,

Stănescu³

1999

Eur Respir J

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According to a recent theoretical model, snoring is related to instability of the upper airway (UA). Factors promoting UA instability include increased gas density. The aim of this study was to test the influence of gas density on simulated snoring production and supraglottic resistance.Supraglottic pressure and flow rate (V ') were measured in 10 healthy seated subjects during simulated snoring. Subjects breathed three different gas mixtures: Helium±oxygen, He 79%±O 2 21% (He±O 2 ); air; and sulphur hexafluoride±oxygen, F 6 S 79%±O 2 21% (F 6 S±O 2 ) administered in a random order. Supraglottic resistance (Rsg) was measured on its linear range during quiet breathing and V ' was measured at the onset and middle of snoring.Linear Rsg increased and V ' conversely decreased with gas density. These data are in agreement with predictions of a mathematical model of the upper airway showing that snoring occurs at lower flow rates when gas density is increased. Eur Respir J 1999; 13: 679±681. Snoring is a cardinal symptom of obstructive sleep apnoea (OSA) syndrome and a frequent finding in otherwise healthy subjects [1]. Previous studies from the authors' laboratory have shown that simulated and spontaneous snoring are characterized by high-frequency oscillations of the soft palate associated with a decrease in oropharyngeal calibre. Reduction of the pharyngeal cross-sectional area increases supraglottic resistance (Rsg) and is associated with flow limitation [2,3].The influence of gas density and viscosity on the upper airway (UA) pressure±flow relationship has not been studied before, except in animals [4].Recently, GAVRIELY and JENSEN [5], based on a theoretical model of UA, found that among other factors, increases in UA resistance and gas density, as well as decrease in UA size promote UA instability and snoring.In this study, the influence of gas density on supraglottic resistance and flow rate (V ') was tested during quiet breathing and during simulated snoring. Materials and methodsTen healthy (five females) nonsmoker subjects aged 22± 30 yrs with normal spirometric data [6] and all nonobese (meanSD body mass index, 32.42.9 kg . m -2 ), volunteered for this study. They were nonsnorers and free of any UA pathology. Written, informed consent was obtained and the experiments were approved by the Ethics Committee of the hospital.V ' was measured with a Fleish No. 2 pneumotachograph (Fleicsh, Lausanne, Switzerland), attached to a tightly fitting silicone face mask. Pressure drop across the pneumotachograph was measured by a 5 cmH 2 O Validyne pressure transducer (Northridge, CA, USA). The airtightness of the mask was verified by measuring the helium level around the border of the mask when the subjects were breathing a 79% He±21% O 2 mixture. The pneumotachograph was calibrated for the three gas mixtures: helium±oxygen, He 79%±O 2 21% (He±O 2 ); air; and sulphur hexafluoride±oxy-gen, F 6 S 79%±O 2 21% (F 6 S±O 2 ) by passing these gases through the pneumotachograph in series with a dry gasometer (Parkinson ...

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Partitioning of respiratory flow resistance in man

Cited by 408 publications

References 0 publications

Clinical Practice Guideline: Improving Nasal Form and Function after Rhinoplasty

Clinical Practice Guideline: Improving Nasal Form and Function after Rhinoplasty

The effect of preoperative anxiety on the incidence of perioperative bronchospasm: a prospective observational study

Influence of gas density on simulated snoring

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