• Tuberculosis and Respiratory Diseases
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• 제40권3호
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• pp.267-273
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• 1993

연구배경 : Airway resistance 측정시 panting 방법은 비정상적인 호흡패턴으로 환자에 따라서는 수행이 어렵고 quiet breathing 방법은 더욱 생리적인 호흡상태하에서 측정이 가능하다. 과거에는 주로 panting을 이용하였으나 최근에는 quiet breathing을 이용하는 추세로 본 연구에서는 panting 및 quiet breathing시에 airway resistance를 측정하여 이를 비교하였다. 방법 : 정상대조군 및 호흡기질환군을 대상으로 유량기량곡선을 측정하고, body plethysmograph를 이용하여 airway resistance를 quiet breathing과 panting시에 각각 측정하였다. 결과: 1) Quiet breathing과 panting시 측정한 airway resistance는 높은 상관관계를 보였다(Raw tot; 0.887, Raw 0.5; 0.921, p<0.05). 2) Panting시 quiet breathing에 비하여 Raw tot는 21.2%. Raw 0.5는 22.1%의 감소율을 보였으며, Inspiratory와 expiratory Resistance의 측정이 가능하였던 경우 Raw insp은 29.3%, Raw exp은 40.6%의 감소율을 보였다. 3) Panting시 airway resistance의 감소율은 호흡기질환군보다 대조군에서 더 컸다. 4) Panting시 specific airway conductance가 유의하게 증가되었으므로 airway resistance의 감소는 thoracic gas volume의 차이와는 관련이 없었다. 5) Panting시 quiet breathing에 비하여 airway resistance가 감소하지 않는 환자는 비교적 airway resistance가 커서 panting을 잘 수행하지 못하는 환자로 추정된다. 결론 : Airway resistance 측정시 환자의 수행능력에 따라 quiet breathing 혹은 panting 방법을 이용할 수 있으나 panting시 quiet breathing보다 결과가 약 20% 감소됨을 고려하여야 하며, 정상군 및 폐질환군에서 panting보다 quiet breathing이 airway resistance를 측정하는 더 좋은 방법으로 생각된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권2호
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• pp.157-161
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• 2001

The purpose of this study cephalometrically evaluated changes in the posterior airway space for patients with obstructive sleep apnea syndrome(OSAS) before and after surgical advancement of the maxilla and mandible. The change in calculated airway resistance was correlated with the respiratory disturbance index(RDI). Twenty cephalometric radiographs were traced before and after surgery to determine the posterior airway area and calculate resistance. Polysomnograms of each patient were obtained before and after surgery. All patients had a decrease in calculated airflow resistance in the airway. The mean amount of resistance was 865.15 before surgery, decreasing to 192.65 after surgery (p<0.01). Eighty-five percent of the patients experienced improvement in their RDI. Reduction in the RDI appears to be due to an increase in the posterior airway space and decrease in flow resistance.

• 대한치과교정학회지
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• 제20권1호
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• pp.47-59
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• 1990

Respiration is one of the most important functions which are carried out in stomatognathic system. When nasal orifice is obstructed or the resistance of upper airway is increased mouth breathing is initiated. Mouth breathing is regarded as an important etiologic factor of dentofacial anomalies. This experiment was performed to observe the influences of metabolic acidosis, tracheal resistance and vagotomy on mouth breathing. After rabbits were anesthetized with sodium pentobarbital, a pair of wire electrode was inserted into mylohyoid muscle, anterior belly of digastric muscle and dilator naris muscle to record EMG activity. Femoral vein and artery were cannulated for infusion of 0.3N HCl and collection of blood sample to determine the blood pH, and tracheal intubation was done to control airway resistance. Mouth breathing was induced by metabolic acidosis. Increase of the airway resistance through tracheal cannula intensified the activity of dilator naris, mylohyoid and digastric muscle. The higher the resistance, the larger the EMG amplitude. After bilateral vagotomy, respiratory volume and inspiatory time were increased and the activities of dilator naris, mylohyoid and digastric muscle were strengthened. It was concluded that the muscle activity related to mouth breathing was induced by metabolic acidosis and increase of tracheal tube resistance.

• Tuberculosis and Respiratory Diseases
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• 제42권2호
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• pp.218-225
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• 1995

연구배경: 기도저항은 body plethysmograph를 이용하여 flow/alveolar pressure의 관계를 측정함으로써 얻어질 수 있는데, 기도저항이 정상인 경우 oscillooscope 상에서 얻어지는 resistance curve가 거의 linear 하나 증가된 경우에는 그 모양이 기울어지거나 loop을 형성하는 경우가 많아 이러한 curve를 분석하여 환자의 임상평가에 도움이 되는 결과를 얻고자 하였다. 방법: 기도저항이 증가되어 있는 환자를 대상으로 body plethysmograph에서 quiet breathing시에 얻어진 resistance curve의 형태를 분석하여 폐기능을 비교하였다. 결과: 1) Resistance curve는 type 1: linear, type 2: ovoid, type 3: sigmoid, type 4: scoop, type 5: paisley의 5가지 형태로 구분할 수 있었으며, 1예를 제외한 type 3과 type 4 및 5는 loop을 형성하였다. 2) Curve의 형태가 특정 질환에 특징적이지는 않았으나 급성질환은 주로 type 1, 및 2, 만성기류폐쇄는 주로 type 3, 4 및 5에 속하였으며, 기관지 천식이나 오래된 폐결핵은 그 정도에 따라 type 1 에서 5까지의 형태를 모두 보였다. 3) Type 1에서 type 5로 갈 수록, loop을 형성 할 수록 기도폐쇄가 심하고 기도저항이 증가되며 잔기량이 커지는 경향을 보였다. 결론: 기도저항을 측정할 경우 기도저항의 측정치 뿐 아니라 resistance curve를 분석하여 기도폐쇄와 air trapping의 정도를 판단하는데 도움을 얻을수 있으며, resistance curve의 모양이 특정 질환에 특징적이지는 않았지만 호기시 loop이 형성되는 경우 심한 기도폐쇄를 시사하였다.

• Journal of Oral Medicine and Pain
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• 제23권1호
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• pp.65-73
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• 1998

This study evaluated whether substantial airflow resistance changes occurred by changing jaw position in normal and snoring subjects. A case-control design was utilized to assess group differences. Subjects included 11 snoring patients and 10 non-snoring subjects. Airway resistance was assessed using a whole body plethysmograph. Subjects in this study had their mouth opening standardized to a position of 7 mm of vertical separation and the resistance was measured under the following conditions; normal jaw position and 2/3 maximum protrusive jaw position. The results were as follows : 1. The airway resistance was higher in snoring group than in non-snoring group. 2. Both groups had a significant decrease in their airflow resistance upon jaw protrusion. In conclusion, these data document that airflow resistance can be significantly influenced by jaw positioning. Moving the jaw in a protrusive position produced reduction of resistance.

• The Journal of Korean Physical Therapy
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• 제16권1호
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• pp.1-13
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• 2004

Airway clearance technique are used to aid in mucus clearance in a variety of disease states. In this review I discuss airway physiology including airway mucus, action of airways, and airway resistance and review the literature and theory regarding forced expiratory technique, active cycle of breathing technique, and autogenic drainage. Also, I look at the appropriate device such as positive expiratory pressure mask(PEP mask), Flutter, and HFCWO(Vest system) which can be applied in the field of respiratory physical therapy. This study is provided as the basic resource regarding the application method of respiratory physical therapy.

• 대한의용생체공학회:의공학회지
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• 제13권3호
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• pp.209-216
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• 1992

A new experimental technique is proposed to localize the flow limiting segment(FLS) during forced expiration. The present technique is based on the pressure drip across FLS and a consequent change in airway resistance, which can provide an accurate and objective location of FLS. During forced expiratory maneuver artificially induced by a strong negative pressure (-100mmHg) applied at the trachea in an anesthetized open chest dog, airway resistance( R) was calculated from air flow and airway pres- sure signals at various airway locations and lung volumes, At the lung volumes above 10 % VC, FLS located in the trachea 6cm lower from the larynx. With the lung volume decreased below 8% VC, FLS jumped upstream to End-3rd generation of the airway. These results were similar with the previous reports from excised dog lungs, which demonstrated the validity of the present technique. Since the present technique provides a more objective measure of FLS location, it would be useful in future studies of expiratory flow limitation.

• 수면정신생리
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• 제11권1호
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• pp.5-9
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• 2004

Obstructive sleep apnea (OSA) is a common disorder characterized by recurrent cessation of breathing due to complete or partial upper airway occlusion during sleep. The incompetent tone of palatal, pharngeal, and glossal muscles which fail to maintain airway patency during sleep causes narrowing of the airway dimension and increased resistance of breathing. The identification of the sites of upper airway obstruction in patients with OSA is important in understanding the pathogenesis and deciding the treatment modality of snoring and/or OSA. Various upper airway imaging modalities have been used to assess upper airway size and precise localization of the sites of upper airway obstruction during sleep. Dynamic imaging modalities enabled assessment of dimensional changes in the upper airway during respiration and sleep. This article focused on reviews of various upper airway imaging modalities, especially dynamic upper airway imaging studies providing important information on the pathogenesis of OSA.

• 대한간호학회지
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• 제44권2호
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• pp.149-158
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• 2014

Purpose: This study was conducted to compare effects of open and closed suctioning methods on lung dynamics (dynamic compliance, tidal volume, and airway resistance) and hypoxemia (oxygen saturation and heart rate) in mechanically ventilated patients. Methods: This study was a cross-over repeated design. Participants were 21 adult patients being treated with endotracheal intubation using a pressure-controlled ventilator below Fraction of Inspired Oxygen ($FiO_2$) 60% and PEEP $8cmH_2O$. Data were collected at baseline and 1, 2, 3, 4, 5, and 10 minutes after suctioning. Data were analyzed using two-factor ANOVA with repeated measures on time and suctioning type. Results: Effects of the interaction between suction type and time were significant for oxygen saturation and heart rate but not significant for dynamic compliance, tidal volume, or airway resistance. Prior to performance of suctioning, tidal volume and oxygen saturation were significantly lower, but airway pressure and heart rate were significantly higher using the closed suctioning method as compared with the open suctioning method. Conclusion: For patients on ventilator therapy below $FiO_2$ 60% and PEEP $8cmH_2O$, open suctioning performed after delivery of 100% $FiO_2$ using a mechanical ventilator may not have as much negative impact on lung dynamics and hypoxemia as closed suctioning.

• Archives of Pharmacal Research
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• 제23권6호
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• pp.535-547
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• 2000

Recent findings indicate that mechanical strain (deformation) exerted by the extracellular matrix modulates activation of airway smooth muscle cells. Furthermore, cytoskeletal organization in airway smooth muscle appears to be dynamic, and subject to modulation by receptor activation and mechanical strain. Mechanosensitive modulation of crossbridge activation and cytoskeletal organization may represent intracellular feedback mechanisms that limit the shortening of airway smooth muscle during bronchoconstriction. Recent findings suggest that receptor-mediated signal transduction is the primary target of mechanosensitive modulation. Mechanical strain appears to regulate the number of functional G-proteins and/or phospholipase C enzymes in the cell membrane possibly by membrane trafficking and/or protein translocation. Dense plaques, membrane structures analogous to focal adhesions, appear to be the primary target of cytoskeletal regulation. Mechanical strain and receptor-binding appear to regulate the assembly and phosphorylation of dense plaque proteins in airway smooth muscle cells. Understanding these mechanisms may reveal new pharmacological targets for control1ing airway resistance in airway diseases.