• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1326-1331
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• 1997

Background : Weaning is the process of switching a patient from mechanical ventilator to spontaneous breathing. A number of different weaning techniques can be employed. At recent study, conventional spontaneous breathing trial was superior to other techniques, such as intermittent mandatory ventilation(IMV) or pressure support ventilation(PSV). But adequate observation time of the spontaneous breathing trial was not determined. We reported the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotrachial tube. In this study, we tried to shorten the spontaneous breathing time from 60 minutes to 30 minutes. If weaning success was predicted after 30 minutes spontaneous breathing, extubation was done without reconnection with ventilator. Methodes : Subjects consisted of 42 mechanically ventilated patients from August 1994 to July 1995. The weaning trial was done when the patients recovered sufficiently from respiratory failure that originally required ventilatory assistance, the patients became alert and showed stable vital sign, and arterial $O_2$ tension was adequated($PaO_2$ > 55 mmHg) with less than 40% of inspired oxygen fraction. We conducted a careful physical examination when the patients was breathing spontaneously through the endobronchial tube for 30 minutes. We terminated the trial if a patients was any of following signs of distress; cyanosis, diaphoresis, tachypnea(above 30 breaths per minute), and extreme tachycardia. Patients who had none of this features during spontaneous breathing for 30 minutes were extubated promptly. Result : 17 weaning trials of 15 patients were done in 42 mechanically ventilated patients. Successful weaning and extubation was possible in 14 trials of total 17 trials. In this 14 patients, 8 patients were extubated after 30 minutes spontaneous breathing, 3 patients were extubated after 60 minutes spontaneous breathing, and 3 patients needed over 3 hours for extubation from weaning. We found similar overall success rate compared with weaning following a 60 minutes spontaneous breathing trial. Conclusion : From the result of present study, we believe that weaning and extubation from mechanical ventilation following a 30 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.361-369
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• 1995

Background: A number of different weaning techniques can be employed such as spontaneous breathing trial, Intermittent mandatory ventilation(IMV) or Pressure support ventilation(PSV). However, the conclusive data indicating the superiority of one technique over another have not been published. Usually, a conventional spontaneous breathing trial is undertaken by supplying humidified $O_2$ through T-shaped adaptor connected to endotracheal tube or tracheostomy tube. In Korea, T-tube trial is not popular because the high-flow oxygen system is not always available. Also, the timing of extubation is not conclusive and depends on clinical experiences. It is known that to withdraw the endotracheal tube after weaning is far better than to go through any period. The tube produces varying degrees of resistance depending on its internal diameter and the flow rates encountered. The purpose of present study is to evaluate the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube. Methods: We analyzed the result of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube in 18 subjects from June, 1993 to June, 1994. They consisted of 9 males and 9 females. The duration of mechanical ventilation was from 38 hours to 341 hours(mean: $105.9{\pm}83.4$ hours). In all cases, the cause of ventilator dependency should be identified and precipitating factors should be corrected. The weaning trial was done when the patient became alert and arterial $O_2$ tension was adequate($PaO_2$ > 55mmHg) with an inspired oxygen fraction of 40%. We conducted a careful physical examination when the patient was breathing spontaneously through the endotracheal tube. Failure of weaning trial was signaled by cyanosis, sweating, paradoxical respiration, intercostal recession. Weaning failure was defined as the need for mechanical ventilation within 48 hours. Results: In 19 weaning trials of 18 patients, successful weaning and extubation was possible in 16/19(84.2 %). During the trial of spontaneous breathing for 60 minutes through the endotracheal tube, the patients who could wean developed slight increase in respiratory rates but significant changes of arterial blood gas values were not noted. But, the patients who failed weaning trial showed the marked increase in respiratory rates without significant changes of arterial blood gas values. Conclusion: The result of present study indicates that weaning from mechanical ventilation following a 60 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method. Extubation can be done at the same time of successful weaning except for endobronchial toilet or airway protection.

• Journal of Korean Academy of Nursing
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• v.30 no.4
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• pp.995-1005
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• 2000

This study was performed to identify the physiological and psychological variables related to successful weaning from a mechanical ventilator. The subjects of this study were 22 patients who received mechanical ventilation therapy for more than 3 days in intensive care units. Before the weaning trial, baseline data for following physiologic variables were obtained: spontaneous respiration rate, blood pressure, pulse rate, PaO2, PaCO2, PEEP, static compliance, minute ventilation, tidal volume, rapid shallow breathing index(f/VT), SaO2, PaO2/FiO2 and mean arterial pressure. During spontaneous breathing, physiologic and psychologic variables such as vital signs, ABG, perspiration, chest retraction, paradoxical respiration, dyspnea, anxiety, confidence and efficacy were measured. Successful weaning was defined as sustaining spontaneous respiration over 24 hours after extubation. Weaning failure was defined as the development of more than one of following signs: (1) hypoxemia, (2) CO2 retention or (3) perspiration, tachypnea, chest retraction, tachycardia, arrhythmia, hypotension or hypertension. Subjects (N=18) who successfully weaned from mechanical ventilator were compared with subjects (N=4) who failed. The results are as follows; Eighteen percents of the subjects failed during the weaning trial. Most subjects in the failed group were mechanically ventilated for long-time. This result shows that the success of weaning is more difficult in long-term ventilation patients. In the baseline data that was measured before weaning trial, the mean score of PaO2 in the successfully weaned group was 121mmHg. This is significantly higher than the mean score of PaO2 in the failed group(95mmHg). However, the scores of pH, tidal volume, f/VT, pulse rates, blood pressure, mean airway pressure, SaO2, and PaCO2 were similar between the two groups. Specially the scores of f/VT index as a predominant predictor for successful weaning were not significant (f/VT=44.4) and (f/VT=47). During spontaneous breathing, the scores of dyspnea and anxiety level in the successfully weaned group were less than those of the failed group. On the contrary, the scores of confidence and efficacy in the successful group were greater than those of the failed group. In conclusion, the baseline data that were measured before weaning trial were similar between the both groups, therefore future studies are needed to focus on searching other variables besides physiological parameters related to weaning outcome.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.124-131
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• 2003

The concentration of nitrous oxide in dental environment has increased especially in pediatric department. In pediatric department frequently met the behavior disordered patients who need the deep sedation. As the deeply sedated patients could not respond well to verbal command, the amount of mouth breathing would be increased especially with mouth prop which backward transposition of mandible. Inhalation of low concentration of nitrous oxide for a long duration has caused various side effects such as spontaneous abortion and inhibition of methionine synthetase activity which is harmful to DNA synthesis. For evaluation of factors of mouth breathing during deep sedation. The author measured the concentration of nitrous oxide in breathing zone by the change of the scavenging methods. One is drain the gas through the tail part of reservoir bag of Jackson Ree's system naturally. Another is scavenge from tail portion of reservoir bag with negative pressure. Last one is scavenge from nasal mask with negative pressure. The nitrous oxide concentration in breathing zone was the lowest in nasal part drainage but high above the recommended concentration of NIOSH. The order of nitrous concentration in breathing zone was: natural drainage, tail part with negative pressure, nasal part with negative pressure. This would reflect the order of resistance of nasal airway and showed the amount of mouth breathing. From the above experiment, the resistance of nasal airway by the increment of gas flow in corrugating tube and reservoir bag would be one of the causative factors of mouth breathing in deeply sedated patients.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.4
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• pp.221-228
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• 2023

Background: We assessed the relationship between patient age and remifentanil dosing rate in patients managed under general anesthesia with spontaneous breathing using low-dose remifentanil in sevoflurane. Methods: The participants were patients with an American Society of Anesthesiologists Physical Status of 1 or 2 maintained under general anesthesia with low-dose remifentanil in 1.5-2.0% sevoflurane. The infusion rate of remifentanil was adjusted so that the spontaneous respiratory rate was half the rate prior to the induction of anesthesia, and γ^H (㎍/kg/min) was defined as the infusion rate of remifentanil under stable conditions where the respiratory rate was half the rate prior to the induction of anesthesia for ≥ 15 minutes. The relationship between γ^H and patient age was analyzed statistically by Spearman's correlation analysis. Results: During dental treatment under general anesthesia using low-dose remifentanil in sevoflurane, a significant correlation was detected between γ^H and patient age. The regression line of y = - 0.00079 x + 0.066 (y-axis; γ^H, x-axis; patient's age) was provided. The values of γ^H provide 0.064 ㎍/kg/min at 2 years and 0.0186 ㎍/kg/min at 60 years. Therefore, as age increases, the dosing rate exhibits a declining trend. Furthermore, in the dosing rate of remifentanil when the patient's respiratory rate was reduced by half from the preanesthetic respiratory rate, the dosing rate provided was around 0.88 mL/h in all ages if the remifentanil was diluted as 0.1 mg/mL. EtCO₂ showed 51.0 ± 5.7 mmHg, and SpO₂ was controlled within the normal range by this method. In addition, all dental treatments were performed without major problems, such as awakening and body movement during general anesthesia, and the post-anesthetic recovery process was stable. Conclusion: General anesthesia with spontaneous breathing provides various advantages, and the present method is appropriate for minimally invasive procedures.

• Journal of Chest Surgery
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• v.26 no.10
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• pp.812-814
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• 1993

Six patients with flail chest were performed operative stabilization with Judet`s Struts.The indications of opertive stabilization were exploratory thoracotomy or laparotomy in 4 patients, and severe chest pain due to displaced ribs which deteriorated respiratory pattern and gas exchange in 2 patients. After operation, all patients became comfortable and complained less pain.Two patients restored spontaneous breathing without ventilator therapy and 2 patients were ventilated during 4 days and 5 days, respectively.There were no morbidity and mortality related to operative stabilization.

• Journal of Chest Surgery
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• v.14 no.2
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• pp.135-139
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• 1981

Thymolipoma is extremely uncommon benign mediastinal tumor consisting of fatty and thymic tissue. Only 50 verified cases have been reported in the world literatures. This one case is the first reported example of surgically treated thymolipoma associated with spontaneous pneumothorax. A thirty-two year old male patient had been in good health until two days prior to admission, when he noted sudden dyspnea associated with an aching pain over the left precordium. The dyspnea and chest pain had become progressively worse. The physical examination revealed that left hemithorax was tympanic sound on percussion and absence of breathing sound on auscultation and point of maximal impulse was located on the 4th intercostal space at the left sternal border. Emergency closed thoracostomy was performed under the impression of tension type spontaneous pneumothorax of the left lung. After closed thoracostomy, point of maximal impulse was not changed inspire of full expansion of the left lung and chest X-ray was strongly suggested pericardial effusion or cardiomegaly which couldn`t account for by clinical course and hemodynamic evidence. EKG, echocardiogram, bronchofiberoscophy, bronchogram and diagnostic thoracentesis was performed. On Dec. 8, 1980, operation was performed under the impression of mediastinal tumor in the anterior mediastinum. At left posterolateral thoractomy, a large fatty mass, measuring 35 x 27 x 13 Cm in dimension and weighing 3350 gm, was resected and multiple bullae on the apicoposterior segment of the left upper lobe was resected and continuously sutured. The pathologic diagnosis of the fatty mass was thymolipoma. The postoperative course was uneventful and discharged in good general conditions.

• Acute and Critical Care
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• v.33 no.4
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• pp.260-268
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• 2018

Background: The purpose of this study was to evaluate the clinical application of modified Burns Wean Assessment Program (m-BWAP) scoring at first spontaneous breathing trial (SBT) as a predictor of successful liberation from mechanical ventilation (MV) in patients with endotracheal intubation. Methods: Patients requiring MV for more than 72 hours and undergoing more than one SBT in a medical intensive care unit (ICU) were prospectively enrolled over a 3-year period. The m-BWAP score at first SBT was obtained by a critical care nursing practitioner. Results: A total of 103 subjects were included in this study. Their median age was 69 years (range, 22 to 87 years) and 72 subjects (69.9%) were male. The median duration from admission to first SBT was 5 days (range, 3 to 26 days), and the rate of final successful liberation from MV was 84.5% (n=87). In the total group of patients, the successful liberation from MV group at first SBT (n=65) had significantly higher m-BWAP scores than did the unsuccessful group (median, 60; range, 43 to 80 vs. median, 53; range, 33 to 70; P<0.001). Also, the area under the m-BWAP curve for predicting successful liberation of MV was 0.748 (95% confidence interval, 0.650 to 0.847), while the cutoff value based on Youden's index was 53 (sensitivity, 76%; specificity, 64%). Conclusions: The present data show that the m-BWAP score represents a good predictor of weaning success in patients with an endotracheal tube in place at first SBT.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4429-4436
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• 2013

Measurements of CNR(Contrast to Noise Ratio) and SNR(Signal to Noise Ratio) of T-spine breathing technique (TBT) using spontaneous breathing and T-spine exhalation technique (TET) with full exhalation were carried out, and with which the more appropriate method was suggested. Both TBT and TET were examined in a sample of fifty-three patients who visit to our hospital for spinal disease from June 2012 to November 2012. All images were evaluated with CNR measured from the differences between the mean pixels and contrast density as setting ROI of spinous process, pedicle, vertebral body, intervertebral foramen, and intervertebral disk using Image J. SNR was measured with the mean pixels and the standard deviation as setting ROI of vertebral body using Image J. In CNR comparison and SNR comparison of TET and TBT, TBT was indicated as excellent in ROI of pedicle, vertebral body, intervertebral foramen and intervertebral disk, and statistical analysis were significant(p<.01). As TBT indicated excellent images compared to the existing T-spine lateral radiography, T-spine lateral radiography would be reestablished and significant as applying to various medical institutions.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.639-645
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• 1997

The purpose of the present study is to determine the role of muscarinic cholinergic receptors of posterior hypothalamus in the central blood pressure regulation when respiration is controlled. In anesthetized and artificially ventilated rats, vasodepressor response was evoked by injection of L-glutamate(10 nmol) neuroexcitatory amino acid into the posterior hypothalamic area. The injection of $carbachol(0.5{\sim}8\;nmol)$ into the same area induced dose-dependent vasodepressor and bradycardic responses. Pretreatment with atropine(4 nmol) completely blocked the vasodepressor response to carbachol(2 nmol). In contrast, in spontaneously breathing rats, the injection of carbachol(8 nmol) into the posterior hypothalamic area induced the vasopressor and tachycardic responses. These results suggest that the muscarinic cholinergic receptors in the posterior hypothalamic area primarily play an inhibitory role in the central regulation of blood pressure and heart rate.