• The Korean Journal of Pain
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• v.28 no.2
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• pp.144-147
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• 2015

Recently, percutaneous epidural neuroplasty has become widely used to treat radicular pain caused by spinal stenosis or a herniated intervertebral disc. A 19-year-old female patient suffering from left radicular pain caused by an L4-L5 intervertebral disc herniation underwent percutaneous epidural neuroplasty of the left L5 nerve root using a Racz catheter. After the procedure, the patient complained of acute motor weakness in the right lower leg, on the opposite site to where the neuroplasty was conducted. Emergency surgery was performed, and swelling of the right L5 nerve root was discovered. The patient recovered her motor and sensory functions immediately after the surgery. Theoretically, the injection of a large volume of fluid in a patient with severe spinal stenosis during epidural neuroplasty can increase the pressure on the opposite side of the epidural space, which may cause injury of the opposite nerve by barotrauma from a closed compartment. Practitioners should be aware of this potential complication.

• The Korean Journal of Emergency Medical Services
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• v.16 no.2
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• pp.67-74
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• 2012

Purpose : The purpose of this study is to get basal user guidelines of safer bag-valve-mask application on patient with normal pulmonary patho-physiologic condition. Methods : This study was accomplished by pre-qualified 25 EMS junior grade students. Participants were instructed randomly compress bag to one-third, half and total and also with differesnt compression speed. Resultant tidal volumes and mean airway pressures obtained in RespiTrainer were analysed in relation to the each compression depth and rate. Results : Demographic difference does not affect tidal volume with any compression depth and rate change. Increasing compression depth is correlated with tidal volume increasement at any compression rate and also with mean airway pressure. If the compression depth is same, compression rate change did not affect significantly the resultant tidal volume or mean airway pressure. Conclusion : Hand size, Experience, BMI dose not affect tidal volume. Compress the 1600 ml bag half to total amount is safe way to offer sufficient tidal volume without risky high airway pressure delivery to patient airway who with normal lung patho-physiologic condition.

• Journal of Biomedical Engineering Research
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• v.14 no.1
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• pp.89-96
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• 1993

During high frequency ventilation (HFV), mean alveolar pressure has been measured to increase with mean airway opening pressure controlled at a constant level in both humans and experimental animals. Since this phenomenon could potentiate barotrauma limiting advantages of HFV, the present study theoretically predicted the difference between menu alveolar and airway opening pressures ($MP_{alv}$). In a Weibel's trumpet airway model, approximated formula for $MP_{alv}$ was derived based on momentum conservation assuming a uniform velocity profile. The prediction, equation was a func pion of gas density($\rho$), mean flow rate(Q), and diameter of the airway opening where the pressure measurement was made($D_0$) : $MP_{alv}=4{\rho}(Q/D_0^{2})^2$. This was a result of the difference in crosssectional area between the alveoli and the airway opening. A simple aireway model experiment was performed and the results well fitted to the prediction, which demonstrated the validity of the present analysis. Previously reported $MP_{alv}$ data from anesthetized dogs in supine position were comparable to the predicted values, indicating that the observed dissociation between mean alveolar and airway opening pressures during HFV can be explained by this innate geometric (or cross-sectional area) asymmetry of the airways. In lateral position, however, the prediction substantially underestimated the measurements suggesting involvement of other important physiological mechanisms.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.39-46
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• 1989

The tracheobronchial histopathologic findings in 7 healthy cats used with high frequency oscillation ventilation (HFOV) were compared with those in 6 cats used with conventional mechanical ventilation (CMV). 4-point, 9-variable scoring system was used to evaluate the injury in the trachea, right & left main bronchi and parenchyme. The following results were obtained ; 1) The tracheobronchial tree received HFOV had no significant damage compared with CMV (P>0.05). 2) Intraepithelial mucus loss and emphysema were s lightly more prominent in CMV groups. As above results ; the tracheobronchial histopathologic difference was not prominent between CMV and HFOV groups received with relatively short period, however, the cellular function and barotrauma may be more prominent in CMV groups. From now on, as causes of tracheobronchial injury in HFV, interaction between humidification and mechanical trauma considers further study.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.56-59
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• 2006

Background: Spontaneous pneumomediastinum (SPM) is a relatively rare and benign condition that generally occurs in young adults without any precipitating factor or disease. The purpose of this study was to assess whether more uncomforting diagnostic procedures are necessary and to establish standards in the diagnosis and treatment of spontaneous pneumomediastinum. Material and Method: A retrospective study was done on 18 patients from the hospitals of Hanyang University Seoul Hospital and Hanyang University Guri Hospital between February, 1997 and June, 2004. All patients had presence of mediastinal air without a pneumothorax and no evidence of trauma or barotrauma. Result: Among the 18 patients, the majority were male patients with only two female patients. Their mean age was 20.95 years old with standard deviation of 14.3 years. The most common complaints were chest pain, dyspnea, and coughing. Evaluation included simple chest roentgenogram in all patients, 10 patients had a chest tomographic scan, 10 patients had an esophagoscopic exam, 6 patients had a bronchofiberoscopic exam, and 3 patients had an esophagogram done. The mean hospital stay was 10.9 days. All patients were treated conservatively and in a follow-up of 1 $\∼$ 8 years only one recurrence was found. Conclusion: SPM is caused by alveolar rupture in the pulmonary interstitium leading to dissection of air towards the hilum and mediastinum. Although SPM is a self-limiting condition, evaluation should include chest roentgenogram and chest tomographic scans to rule out any other secondary condition. More aggressive evaluation seems unnecessary.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.413-418
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• 1997

From January, 1992 to June, 1996, )7 patients with flail chest were treated at Sonnchunhyang university hospital. 15 patients were managed by internal fixation of fractured ribs, whereas the remaining 22 patients were managed by endotracheal intubation and intermittent positive-pressure ventilation alone. There were no difference between two groups in age, sex, the severity of injury to the chest wall and the nature of associated injuries. Average dur'Btion of assisted ventilation was 5.7 $\pm$ 1.7 days in the patients treated by internal fixation versus 8.7 $\pm$ 3.3 days In the patients treated by continuous me hanical ventilation. Average stay in the intensive care unit was 8.3 $\pm$ 3.9 days for the patients treated by internal fixation, whereas it was $13.2\pm4.1$ days in the group treated by continuous mechanical ventilation alone. In the group treated by internal fixation, complications were 3 atelectases(20.0%), 1 pneumonia(6.7%), 2 operative wound problems(12.3%) and 1 barotrauma(6.7%). In the other group, 7 atelectases(31.8%), 4 pneumonitis(18.2%), 2 empyemas(9.1%) and 3 barotraumas(1).6%). The mortality rate was 13.3%(2/15) in the surgically treated patients, whereas it was 22.7%(5122) in the other group. The treatment of flail chest by internal fixation resulted in speedy recovery, decreased complications and mortalities, and better ultimatc cosmetic and functional results.

• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.201-209
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• 1996

Background : Auto-PEEP which develops when expiratory lung emptying is not finished until the beginning of next inspiration is frequently found in patients on mechanical ventilation. Its presence imposes increased risk of barotrauma and hypotension, as well as increased work of breathing (WOB) by adding inspiratory threshold load and/or adversely affecting to inspiratory trigger sensitivity. The aim of this study is to evaluate the relationship of auto-PEEP with WOB and to evaluate the effect of PEEP applied by ventilator (external PEEP) on WOB in patients with auto-PEEP. Method : 15 patients, who required mechanical ventilation for management of acute respiratory failure, were studied. First, the differences in WOB and other indices of respiratory mechanics were examined between 7 patients with auto-PEEP and 8 patients without auto-PEEP. Then, we applied the 3 cm $H_2O$ of external PEEP to patients with auto-PEEP and evaluated its effects on lung mechanics as well as WOB. Indices of respiratory mechanics including tidal volume ($V_T$), repiratory rate, minute ventilation ($V_E$), peak inspiratory flow rate (PIFR), peak expiratory flow rate (PEFR), peak inspiratory pressure (PIP), $T_I/T_{TOT}$, auto-PEEP, dynamic compliance of lung (Cdyn), expiratory airway resistance (RAWe), mean airway resistance (RAWm), $p_{0.1}$, work of breathing performed by patient (WOB), and pressure-time product (PTP) were obtained by CP-100 Pulmonary Monitor (Bicore, USA). The values were expressed as mean $\pm$ SEM (standard error of mean). Results : 1) Comparison of WOB and other indices of respiratory mechanics in patients with and without auto-PEEP : There was significant increase in WOB ($l.71{\pm}0.24$ vs $0.50{\pm}0.19\;J/L$, p=0.007), PTP ($317{\pm}70$ vs $98{\pm}36\;cm$ $H_2O{\cdot}sec/min$, p=0.023), RAWe ($35.6{\pm}5.7$ vs $18.2{\pm}2.3\;cm$ H2O/L/sec, p=0.023), RAWm ($28.8{\pm}2.5$ vs $11.9{\pm}2.0cm$ H2O/L/sec, p=0.001) and $P_{0.1}$ ($6.2{\pm}1.0$ vs 2.9+0.6 cm H2O, p=0.021) in patients with auto-PEEP compared to patients without auto-PEEP. The differences of other indices including $V_T$, PEFR, $V_E$ and $T_I/T_{TOT}$ showed no significance. 2) Effect of 3 cm $H_2O$ external PEEP on respiratory mechanics in patients with auto-PEEP : When 3 cm $H_2O$ of external PEEP was applied, there were significant decrease in WOB ($1.71{\pm}0.24$ vs $1.20{\pm}0.21\;J/L$, p=0.021) and PTP ($317{\pm}70$ vs $231{\pm}55\;cm$ $H_2O{\cdot}sec/min$, p=0.038). RAWm showed a tendency to decrease ($28.8{\pm}2.5$ vs $23.9{\pm}2.1\;cm$ $H_2O$, p=0.051). But PIP was increased with application of 3 cm $H_2O$ of external PEEP ($16{\pm}2$ vs $22{\pm}3\;cm$ $H_2O$, p=0.008). $V_T$, $V_E$, PEFR, $T_I/T_{TOT}$ and Cdyn did not change significantly. Conclusion : The presence of auto-PEEP in mechanically ventilated patients was accompanied with increased WOB performed by patient, and this WOB was decreased by 3 cm $H_2O$ of externally applied PEEP. But, with 3 cm $H_2O$ of external PEEP, increased PIP was noted, implying the importance of close monitoring of the airway pressure during application of external PEEP.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1318-1325
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• 1997

Background : Since the late 1960s, mechanical ventilation has been accomplished primarily using volume controlled ventilation(VCV). While VCV allows a set tidal volume to be guaranteed, VCV could bring about excessive airway pressures that may be lead to barotrauma in the patients with acute lung injury. With the increment of knowledge related to ventilator-induced lung injury, pressure controlled ventilation(PCV) has been frequently applied to these patients. But, PCV has a disadvantage of variable tidal volume delivery as pulmonary impedance changes. Since the concept of combining the positive attributes of VCV and PCV(dual control ventilation, DCV) was described firstly in 1992, a few DCV modes were introduced. Pressure-regulated volume control(PRVC) mode, a kind of DCV, is pressure-limited, time-cycled ventilation that uses tidal volume as a feedback control for continuously adjusting the pressure limit However, no clinical studies were published on the efficacy of PRVC until now. 'This investigation studied the efficacy of PRVC in the patients with unstable respiratory mechanics. Methods : The subjects were 8 mechanically ventilated patients(M : F=6 : 2, $56{\pm}26$ years) who showed unstable respiratory mechanics, which was defined by the coefficients of variation of peak inspiratory pressure for 15 minutes greater than 10% under VCV, or the coefficients of variation of tidal volume greater than 10% under PCV. The study was consisited of 3 modes application with VCV, PCV and PRVC for 15 minutes by random order. To obtain same tidal volume, inspiratory pressure setting was adjusted in PCV. Respiratory parameters were measured by pulmonary monitor(CP-100 pulmonary monitor, Bicore, Irvine, CA, USA). Results : 1) Mean tidal volumes($V_T$) in each mode were not different(VCV, $431{\pm}102ml$ ; PCV, $417{\pm}99ml$ ; PRVC, $414{\pm}97ml$) 2) The coefficient of variation(CV) of $V_T$ were $5.2{\pm}3.9%$ in VCV, $15.2{\pm}7.5%$ in PCV and $19.3{\pm}10.0%$ in PRVC. The CV of $V_T$ in PCV and PRVC were significantly greater than that in VCV(p<0.01). 3) Mean peak inspiratory pressure(PIP) in VCV($31.0{\pm}6.9cm$ $H_2O$) was higher than PIP in PCV($26.0{\pm}6.5cm$ $H_2O$) or PRVC($27.0{\pm}6.4cm$ $H_2O$)(p<0.05). 4) The CV of PIP were $13.9{\pm}3.7%$ in VCV, $4.9{\pm}2.6%$ in PVC and $12.2{\pm}7.0%$ in PRVC. The CV of PIP in VCV and PRVC were greater than that in PCV(p<0.01). Conclusions : Because of wide fluctuations of VT and PIP, PRVC mode did not seem to have advantages compared to VCV or PCV in the patients with unstable respiratory mechanics.