• Tuberculosis and Respiratory Diseases
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• 제69권4호
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• pp.243-249
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• 2010

Background: Chronic obstructive pulmonary disease (COPD) is one of the leading causes of disability and mortality worldwide. The aim of this study was to evaluate the risk factors associated with recurrent hospital admissions for exacerbation of COPD in Korea. Methods: A retrospective study of 77 consecutive patients hospitalized for exacerbation of COPD at Pusan National University Hospital during the time period January 2005 to May 2008 was performed. The information was collected from the hospitalization period: clinical information, spirometric measures, and laboratory variables. In addition, socioeconomic characteristics, co-morbidity, anxiety, and depression were reviewed. Frequent readmission was defined as 2 or more hospitalizations in the year following discharge. Results: During the 1-year period after discharge, 42 patients (54.6%) reported one hospital admission and 35 patients (45.4%) reported 2 or more hospital readmissions. Among the 35 frequent readmission patients, 4 had more than 10 readmissions. Univariate analysis showed that a body mass index (BMI) <$18.5kg/m^2$, duration >36 months, forced expiratory volume in 1 second ($FEV_1$) <50% predicted, arterial $CO_2$ partial pressure ($PaCO_2$) >40 mm Hg, and arterial oxygen saturation ($SaO_2$) <95% at discharge were associated significantly with frequent readmissions. The multivariate analysis revealed that BMI <$18.5kg/m^2$, $PaCO_2$ >40 mm Hg at discharge were independently associated with frequent readmissions for exacerbation of COPD. Conclusion: Frequent readmissions for exacerbation of COPD were associated with low BMI and hypercapnia at discharge.

• Current Optics and Photonics
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• 제3권6호
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• pp.555-565
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• 2019

Development of a biomarker for predicting tumor-treatment efficacy is a matter of great concern, to reduce time, medical expense, and effort in oncology therapy. In a preclinical study, we hypothesized that the blood-flow parameter based on laser speckle flowmetry (LSF) could be a potential indicator to estimate the efficacy of breast-cancer treatment. To verify this hypothesis, a 13762-MAT-B-III rat breast tumor was grown in a dorsal skinfold window chamber applied to a nude mouse, and the change in blood flow rate (BFR) - or the speckle flow index (SFI) is used together as the same meaning in this manuscript - was longitudinally monitored during tumor growth and metronomic cyclophosphamide treatment. Based on the daily LSF angiogram, several BFR parameters (baseline SFI, normalized SFI, and △rBFR) were compared to tumor size in the normal, treated, and untreated tumor groups. Despite the incomplete tumor treatment, we found that the daily changes in all BFR parameters tended to have partially positive correlation with tumor size. Moreover, we observed that the changes in baseline SFI and normalized SFI responded one day earlier than the tumor shrinkage during chemotherapy. However, daily variations in the hypercapnia-induced △rBFR lagged tumor shrinkage by one day. This study would contribute not only to evaluating tumor vascular response to treatment, but also to monitoring blood-flow-mediated diseases (in brain, skin, and retina) by using LSF in preclinical settings.

• 수면정신생리
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• 제29권1호
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• pp.4-8
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• 2022

Obesity hypoventilation syndrome (OHS) is defined as the triad of obesity (body mass index, [BMI] ≥ 30 kg/m²), daytime hypercapnia (PaCO2 ≥ 45 mm Hg), and sleep breathing disorder, after excluding other causes for hypoventilation. As the obese population increases worldwide, the prevalence of OHS is also on the rise. Patients with OHS have poor quality of life, high risk of frequent hospitalization and increased cardiopulmonary mortality. However, most patients with OHS remain undiagnosed and untreated. The diagnosis typically occurs during the 5th and 6th decades of life and frequently first diagnosed in emergency rooms as a result of acute-on-chronic hypercapnic respiratory failure. Due to the high mortality rate in patients with OHS who do not receive treatment or have developed respiratory failure, early recognition and effective treatment is essential for improving outcomes. Positive airway pressure (PAP) therapy including continuous PAP (CPAP) or noninvasive ventilation (NIV) is the primary management option for OHS. Changes in lifestyle, rehabilitation program, weight loss and bariatric surgery should be also considered.

• 수면정신생리
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• 제16권1호
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• pp.22-27
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• 2009

Regulation of respiration differs significantly between wakefulness and sleep. Respiration during wakefulness is influenced by not only automatic control but also voluntary and behavioral control. Sleep is associated with definite changes in respiratory function. With the onset of sleep, voluntary control of ventilation that overrides automatic control during wakefulness becomes terminated. Also ventilatory response to various stimuli including hypoxemia and hypercapnia is decreased. With these reasons respiration during sleep becomes fragile and unstable so that marked hypoxemia can be happened in patients with lung disease especially during REM sleep. Obstructive sleep apnea may also be developed if upper airway resistance is increased in addition to these blunted ventilatory responses.

• 수면정신생리
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• 제12권1호
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• pp.17-22
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• 2005

Sleep-disordered breathing (SDB) is associated with increased cardiovascular and cerebrovascular morbidity. Epidemiological and clinic-based studies have shown that SDB is related to impaired glucose tolerance and increased insulin resistance, independent of obesity. Despite of a consistent association between SDB and impaired glucose-insulin metabolism, the mechanism underlying this relationship has not been fully elucidated. It is recognized that hypoxemia and hypercapnia that occur in SDB provoke sympathetic nervous activity and catecholamine, epinephrine and norepinephrine, and cortisol are released. Sympathetic hyperactivity and increased catecholamines can impair glucose homeostasis by increasing glycogenolysis and gluconeogenesis, which can result in increased circulating insulin levels and increased risk of insulin resistance. A prospective study is needed to investigate the causal relationship between SDB and impaired glucose-insulin metabolism in a healthy population without diabetes, hypertension and obesity as etiologic risk factors.

• 수면정신생리
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• 제15권2호
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• pp.67-70
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• 2008

Overlap syndrome can be defined as a coexistence of chronic obstructive pulmonary disease (COPD) and sleep apnea-hypopnea syndrome (SAHS). The association of COPD and SAHS has been suspected because of the frequency of both diseases. Prevalence of COPD and SAHS is respectively 10 and 5% of the adult population over 40 years of age. However, a recent study has shown that the prevalence of SAHS is not higher in COPD than in the general population. The coexistence of the two diseases is only due to chance. SAHS does not affect the pathophysiology of COPD and vice versa. Prevalence of overlap syndrome is expected to occur in about 0.5% of the adult population over 40 years of age. Patients with overlap syndrome have a more profound hypoxemia, hypercapnia, and pulmonary hypertension when compared with patients with SAHS alone or usual COPD patients without SAHS. To treat the overlap syndrome, nocturnal noninvasive ventilation (NIV) or nasal continuous positive airway pressure (nCPAP) can be applied with or without nocturnal oxygen supplement.

• 대한기관식도과학회지
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• 제5권2호
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• pp.113-118
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• 1999

Background & Objectives : Nasal resistance which is halfly responsible for airway resistance is known to be influenced by hypoxia, hypercapnia, exercise, pregnancy, alcohol, ammonia and smoking. Smoking is a common part of our sociocultural environment and we have many a times been introduced to its various adverse effects, which have usually been more focused on lung problems. The purpose of this study is to determine any relationship between smoking and nasal resistance and to evaluate it's effective sites. Materials and Methods : Acoustic rhinometry was performed in 25 smokers and 25 nonsmokers who had no nasal symptoms nor abnormal rhinoscopic findings, and used an acoustic rhinometry to measure the distance from nose-piece to the C-notch, cross sectional area at the C-notch, and volume of the nasal cavity from nose-piece to 7cm. The authors compared the data between the two groups. Results : The cross sectional area at the C-notch was significantly decreased(p<0.05) in smoking group. The distance to the C-notch and the volume of nasal cavity were decreased likely in smoking group but there were no significant difference(p>0.05). Conclusion : Smoking reduced the cross sectional area at the C-notch, so increased the nasal resistance. The underlying mechanisms seems to be decreased nasal mucosal reactivity and congestion of the nasal mucosa. The authors believe there should follow more studies on pathophysiologic mechanisms and the histopathologic changes which involve the effect of smoking on nasal structures.

• 대한임상독성학회지
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• 제18권1호
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• pp.42-46
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• 2020

Tetramine toxicity due to sea snail ingestion is generally mild and has a good prognosis. Tetramine toxicity acts on the acetylcholine receptor, affecting the neuromuscular junction and autonomic nervous system. A 78-year-old female patient visited the emergency room with vomiting and dyspnea after eating sea snails. At the time of admission, the vital signs recorded were 140/80 mmHg-105/min-24/min-36.5℃, and 90% oxygen saturation. Arterial blood test revealed hypercapnia (pCO₂ 58.2 mmHg) and respiratory acidosis (pH 7.213, HCO₃^- 22.5 mmol/L), whereas other blood tests showed no specific findings. Due to decreased consciousness and hypoxia, endotracheal intubation and mechanical ventilation were administered to the patient. Successful weaning was accomplished after 12 hrs, and the patient was discharged without any further complications. Although tetramine toxicity rarely results in acute respiratory failure due to paralysis of the respiratory muscle, caution is required whilst treating the patient.

• Tuberculosis and Respiratory Diseases
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• 제78권1호
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• pp.18-22
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• 2015

Interventional lung assist (iLA) effectively reduces $CO_2$ retention and allows protective ventilation in cases of life-threatening hypercapnia. Despite the clinical efficacy of iLA, there are a few major limitations associated with the use of this approach, such as bleeding, thrombosis, and catheter-related limb ischemia. We presented two cases in which thrombotic complications developed during iLA. We demonstrated the two possible causes of thrombotic complications during iLA; stasis due to low blood flow and inadequate anticoagulation.

• Clinical and Experimental Pediatrics
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• 제48권12호
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• pp.1310-1316
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• 2005

Mechanical ventilation in children has some differences compared to in neonates or in adults. The indication of mechanical ventilation can be classified into two groups, hypercapnic respiratory failure and hypoxemic respiratory failure. The strategies of mechanical ventilation should be different in these two groups. In hypercapnic respiratory failure, volume target ventilation with constant flow is favorable and pressure target ventilation with constant pressure is preferred in hypoxemic respiratory failure. For oxygenation, fraction of inspired oxygen($FiO_2$) and mean airway pressure(MAP) can be adjusted. MAP is more important than FiO2. Positive end expiratory pressure(PEEP) is the most potent determinant of MAP. The optimal relationship of $FiO_2$ and PEEP is PEEP≒$FiO_2{\times}20$. For ventilation, minute volume of ventilation(MV) product of tidal volume(TV) and ventilation frequency is the most important factor. TV has an maximum value up to 15 mL/kg to avoid the volutrauma, so ventilation frequency is more important. The time constant(TC) in children is usually 0.15-0.2. Adequate inspiratory time is 3TC, and expiratory time should be more than 5TC. In some severe respiratory failure, to get 8TC for one cycle is impossible because of higher frequency. In such case, permissive hypercapnia can be considered. The strategy of mechanical ventilation should be adjusted gradually even in the same patient according to the status of the patient. Mechanical ventilators and ventilation modes are progressing with advances in engineering. But the most important thing in mechanical ventilation is profound understanding about the basic pulmonary mechanics and classic ventilation modes.