Accuracy assessment of a PION TCI pump based on international standards

BACKGROUND: Inaccuracies associated with target-controlled infusion (TCI) delivery systems are attributable to both software and hardware issues, as well as pharmacokinetic variability. However, little is known about the inaccuracy of the syringe pump operating in TCI mode. This study aimed to evaluate the accuracy of the TCI pump based on international standards.METHODS: A test apparatus for accuracy evaluation of a syringe pump (PION TCI®, Bionet Co. Ltd.) was designed to apply the gravimetric method. Pump accuracy was evaluated in terms of deviation defined by the following equation: infusion rate deviation (%) = (Rate(mea) − Rate(est)) / Rate(est) × 100, where Rate(mea) is the infusion rate (ml/h) as measured by the gravimetric system, and Rate(est) is the infusion rate (ml/h) as estimated by the pump. An infusion rate representing TCI mode was determined from previous clinical trial data which evaluated the predictive performance of the pharmacokinetic model. The PION TCI pump used in that clinical trial was used to evaluate accuracy of the syringe pump. The distribution of infusion rates obtained from the clinical trial was calculated, and the median value of the distribution was determined as the representative value.RESULTS: The representative infusion rate representing TCI mode was 31 ml/h, at which the infusion rate deviation was 4.5 ± 1.6%.CONCLUSIONS: The inaccuracy of the syringe pump contributing to TCI system inaccuracy is insignificant.

Evaluation of Respiratory Dynamics in an Asymmetric Lung Compliance Model / 대한구급학회지

BACKGROUND: Unilateral lung hyperinflation develops in lungs with asymmetric compliance, which can lead to vital instability. The aim of this study was to investigate the respiratory dynamics and the effect of airway diameter on the distribution of tidal volume during mechanical ventilation in a lung model with asymmetric compliance. METHODS: Three groups of lung models were designed to simulate lungs with a symmetric and asymmetric compliance. The lung model was composed of two test lungs, lung1 and lung2. The static compliance of lung1 in C15, C60, and C120 groups was manipulated to be 15, 60, and 120 ml/cmH₂O, respectively. Meanwhile, the static compliance of lung2 was fixed at 60 ml/cmH₂O. Respiratory variables were measured above (proximal measurement) and below (distal measurement) the model trachea. The lung model was mechanically ventilated, and the airway internal diameter (ID) was changed from 3 to 8 mm in 1-mm increments. RESULTS: The mean ± standard deviation ratio of volumes distributed to each lung (VL1/VL2) in airway ID 3, 4, 5, 6, 7, and 8 were in order, 0.10 ± 0.05, 0.11 ± 0.03, 0.12 ± 0.02, 0.12 ± 0.02, 0.12 ± 0.02, and 0.12 ± 0.02 in the C15 group; 1.05 ± 0.16, 1.01 ± 0.09, 1.00 ± 0.07, 0.97 ± 0.09, 0.96 ± 0.06, and 0.97 ± 0.08 in the C60 group; and 1.46 ± 0.18, 3.06 ± 0.41, 3.72 ± 0.37, 3.78 ± 0.47, 3.77 ± 0.45, and 3.78 ± 0.60 in the C120 group. The positive end-expiratory pressure (PEEP) of lung1 was significantly increased at airway ID 3 mm (1.65 cmH₂O) in the C15 group; at ID 3, 4, and 5 mm (2.21, 1.06, and 0.95 cmH₂O) in the C60 group; and ID 3, 4, and 5 mm (2.92, 1.84, and 1.41 cmH₂O) in the C120 group, compared to ID 8 mm (P < 0.05). CONCLUSIONS: In the C15 and C120 groups, the tidal volume was unevenly distributed to both lungs in a positive relationship with lung compliance. In the C120 group, the uneven distribution of tidal volume was improved when the airway ID was equal to or less than 4 mm, but a significant increase of PEEP was observed.

Evaluation of Respiratory Dynamics in an Asymmetric Lung Compliance Model / 대한중환자의학회지

BACKGROUND: Unilateral lung hyperinflation develops in lungs with asymmetric compliance, which can lead to vital instability. The aim of this study was to investigate the respiratory dynamics and the effect of airway diameter on the distribution of tidal volume during mechanical ventilation in a lung model with asymmetric compliance. METHODS: Three groups of lung models were designed to simulate lungs with a symmetric and asymmetric compliance. The lung model was composed of two test lungs, lung1 and lung2. The static compliance of lung1 in C15, C60, and C120 groups was manipulated to be 15, 60, and 120 ml/cmH₂O, respectively. Meanwhile, the static compliance of lung2 was fixed at 60 ml/cmH₂O. Respiratory variables were measured above (proximal measurement) and below (distal measurement) the model trachea. The lung model was mechanically ventilated, and the airway internal diameter (ID) was changed from 3 to 8 mm in 1-mm increments. RESULTS: The mean ± standard deviation ratio of volumes distributed to each lung (VL1/VL2) in airway ID 3, 4, 5, 6, 7, and 8 were in order, 0.10 ± 0.05, 0.11 ± 0.03, 0.12 ± 0.02, 0.12 ± 0.02, 0.12 ± 0.02, and 0.12 ± 0.02 in the C15 group; 1.05 ± 0.16, 1.01 ± 0.09, 1.00 ± 0.07, 0.97 ± 0.09, 0.96 ± 0.06, and 0.97 ± 0.08 in the C60 group; and 1.46 ± 0.18, 3.06 ± 0.41, 3.72 ± 0.37, 3.78 ± 0.47, 3.77 ± 0.45, and 3.78 ± 0.60 in the C120 group. The positive end-expiratory pressure (PEEP) of lung1 was significantly increased at airway ID 3 mm (1.65 cmH₂O) in the C15 group; at ID 3, 4, and 5 mm (2.21, 1.06, and 0.95 cmH₂O) in the C60 group; and ID 3, 4, and 5 mm (2.92, 1.84, and 1.41 cmH₂O) in the C120 group, compared to ID 8 mm (P < 0.05). CONCLUSIONS: In the C15 and C120 groups, the tidal volume was unevenly distributed to both lungs in a positive relationship with lung compliance. In the C120 group, the uneven distribution of tidal volume was improved when the airway ID was equal to or less than 4 mm, but a significant increase of PEEP was observed.

Severe hypoxemia during carinal resection in the lateral position under one-lung ventilation of a non-dependent lung: a case report / 대한마취과학회지

During one-lung ventilation (OLV) in the lateral position, the dependent, ventilated lung receives more blood flow than the non-dependent, non-ventilated lung owing to gravity, improving the match of ventilation and perfusion. Conversely, in the rare clinical situations when OLV is applied to the non-dependent lung, arterial oxygenation can get worse due to considerable shunt flow to the dependent non-ventilated lung. We report a case of severe hypoxemia during carinal resection under OLV of a non-dependent lung. In this case, OLV had to be applied to the non-dependent lung in the lateral position because the bronchus of the non-dependent lung was anastomosed with the trachea, whereas the bronchus of the dependent lung had already been resected for carinal resection. The subsequent hypoxemia resulting from the shunt flow to the dependent non-ventilated lung was treated successfully by ligating the pulmonary artery of the dependent lung.

Transection of a Coopdech bronchial blocker tip during bronchial resection for right upper lobectomy: a case report / 대한마취과학회지

A bronchial blocker (BB) is preferred for lung separation in patients with difficult airways. However, BBs, unlike double-lumen tubes, must be placed in the bronchus of the lung being operated on, hence can be damaged by surgical manipulation. Intubation was unexpectedly difficult in this male patient, so a Coopdech BB was placed in the right mainstem bronchus through a single-lumen tracheoscopic ventilation tube for a thoracoscopic right upper lobectomy. During the bronchial resection, however, the distal tip of the BB was transected and pinched in the staple line, so the staple line was partially opened, and the BB was withdrawn into the trachea. The opened bronchial stump was sutured manually under apnea without conversion to an open thoracotomy, and there was no significant air leakage through the suture line. This case underlines the importance of frequently evaluating the position of a BB during lung surgery.

Bioconversion of Ginsenosides from Red Ginseng Extract Using Candida allociferrii JNO301 Isolated from Meju

Red ginseng (Panax ginseng), a Korean traditional medicinal plant, contains a variety of ginsenosides as major functional components. It is necessary to remove sugar moieties from the major ginsenosides, which have a lower absorption rate into the intestine, to obtain the aglycone form. To screen for microorganisms showing bioconversion activity for ginsenosides from red ginseng, 50 yeast strains were isolated from Korean traditional meju (a starter culture made with soybean and wheat flour for the fermentation of soybean paste). Twenty strains in which a black zone formed around the colony on esculin-yeast malt agar plates were screened first, and among them 5 strains having high beta-glucosidase activity on p-nitrophenyl-beta-D-glucopyranoside as a substrate were then selected. Strain JNO301 was finally chosen as a bioconverting strain in this study on the basis of its high bioconversion activity for red ginseng extract as determined by thin-layer chromatography (TLC) analysis. The selected bioconversion strain was identified as Candida allociferrii JNO301 based on the nucleotide sequence analysis of the 18S rRNA gene. The optimum temperature and pH for the cell growth were 20~30degrees C and pH 5~8, respectively. TLC analysis confirmed that C. allociferrii JNO301 converted ginsenoside Rb1 into Rd and then into F2, Rb2 into compound O, Rc into compound Mc1, and Rf into Rh1. Quantitative analysis using high-performance liquid chromatography showed that bioconversion of red ginseng extract resulted in an increase of 2.73, 3.32, 33.87, 16, and 5.48 fold in the concentration of Rd, F2, compound O, compound Mc1, and Rh1, respectively.

Sensitivity of Whole-Blood Interferon-Gamma Release Assay According to the Severity and the Location of Disease in Patients with Active Tuberculosis / 결핵및호흡기질환

BACKGROUND: The clinical manifestation of M. tuberculosis infection ranges from asymptomatic latent infection, to focal forms with minimal symptoms and low bacterial burdens, and finally to advanced tuberculosis (TB) with severe symptoms and high bacillary loads. We investigated the diagnostic sensitivity of the whole-blood interferon-gamma release assay according to the wide spectrum of clinical phenotypes. METHODS: In patients diagnosed with active TB that underwent QuantiFERON(R) (QFT) testing, the QFT results were compared with patients known to be infected with pulmonary tuberculosis (P-TB) and extra-pulmonary TB (EP-TB). In addition, the results of the QFT test were further analyzed according to the radiographic extent of disease in patients with P-TB and the location of disease in patients with EP-TB. RESULTS: There were no statistical differences in the overall distribution of QFT results between 177 patients with P-TB and 84 patients with EP-TB; the positive results of QFT test in patients with P-TB and EP-TB were 70.1% and 64.3%, respectively. Among patients with P-TB, patients with mild extents of disease showed higher frequency of positive results of QFT test than that of patients with severe form (75.2% vs. 57.1%, respectively; p=0.043) mainly due to an increase of indeterminate results in severe P-TB. Patients with TB pleurisy showed lower sensitivity by the QFT test than those with tuberculous lymphadenitis (48.8% vs. 78.8%, respectively; p=0.019). CONCLUSION: Although QFT test showed similar results between overall patients with P-TB and EP-TB, individual sensitivity was different according to the radiographic extent of disease in P-TB and the location of disease in EP-TB.

Hypercapnic coma at the postanesthesia care unit: A case report / 대한마취과학회지

A 59-year-old woman underwent explorative laparotomy under general anesthesia for mechanical ileus. The patient had rectal cancer with multiple metastasis, and was receiving 1.5-2 mg of intravenous morphine per hour due to severe abdominal pain. After about 3 hours of general anesthesia, the patient was extubated and transferred to postanesthesia care unit. The patient was supplied with 6 L/min of oxygen by facial mask. In 30 minutes, the patient showed no response to verbal order and pain stimulus with sluggish eye reflex, although pulse-oximeter showed 98-99%. After emergent intubation, arterial blood gas was sampled, and the result showed severe acidosis with hypercapnia. The patient was transferred to intensive care unit, and after 1 hour of mechanical ventilation the patient became conscious then fully recovered without further complication.

Association of Tissue Factor Polymorphism with Fibrinolysis and Excessive Bleeding after Open Heart Surgery: A preliminary report / 대한마취과학회지

BACKGOUND: Fibrinolysis, which commonly occurs following cardiopulmonary bypass (CPB), may be related to the excessive bleeding (EB) and morbidity after CPB. It is known that tissue factor (TF), which is triggered by CPB, plays an important role in the initiation of fibrinolysis during and after CPB, however, EB and fibrinolysis after CPB show inter-individual variance. Therefore, in this study, TF -603A/G polymorphism was evaluated to determine if it is associated with fibrinolysis and/or EB and morbidity following CPB. METHODS: RT-PCR was used to determine the TF genotype of each patient. In addition, the amount of blood loss that occurred during the first 24 hours following surgery was documented, and EB was diagnosed when more than 1 L of blood was lost during the first 24 hours following surgery. The D-dimer levels were measured at; a) Time 1; prior to initiation of CPB, b) Time 2; 2 hours after CPB, and c) Time 3; 24 hours after CPB. The oxygen index (OI) was calculated at; 1) OI1; upon admission to the ICU, b) OI2; 24 hrs after admission to the ICU, and c) OI3; 48 hrs after admission to the ICU. The intubation time and the length of the ICU stay were also documented. RESULTS: The serum D-Dimer level of the TF -603AA group (n = 72) measured at time 3 was higher than that of the TF -603GG/GA group (n = 25) measured at the same time. In addition, the incidence of EB and the intubation time of the TF -603AA group were higher than those of the TF -603GG/GA group. Finally, the OI3 of the TF -603AA group was lower than that of the TF -603GG/GA group. CONCLUSIONS: The G allele that is associated with TF -603A/G polymorphism may be protective against fibrinolysis following CPB, therefore, it may also be protective against EB and morbidity following CPB.

Descending Necrotizing Mediastinitis Secondary to Peritonsillar Abscess: A Case Report / 대한흉부외과학회지

Descending necrotizing mediastinitis(DNM) is a rare complication of the oropharyngeal and cervical infection. Descending necrotizing mediastinitis requires an early and aggressive surgical approach to reduce the high morbidity and mortality associated with this disease. A 39-year-old man complained of odynophagia, neck swelling, and disturbance of swallowing with dyspnea. CT scans of the neck suggested a peritonsillar abscess and retropharyngeal and peripharyngeal abscess. He underwent cervical drainage. He remained febrile and complained of severe both pain in both shoulders. On postoperative day 5, a follow-up CT scan confirmed a mediastinal abscess. Reexploration of the neck and right thoracotomy for debridement and drainage of the mediastinal abscess were performed. A large amount of pus was drained from the anterior and posterior mediastinum and its necrotic tissue was debrided. The patient's condition and radiologic findings gradually improved. Cultures of the drain fluid revealed Klebsiella pneumoniae. He was discharged on the 85th hospital day. In our experience, both transcervical drainage and aggressive mediastinal exploration via thoracotomy can lead to an improvement in the survival of the patient with descending necrotizing mediastinitis. CT scanning is useful for early diagnosis of mediastinitis and for follow up.

Surgical Treatment of the Congenital Esophageal Atresia / 대한흉부외과학회지

BACKGROUND: Surgical correction of the full spectrum of esophageal atresia with tracheoesophageal fistula has improved over the years, but the mortality and morbidity assoiated with repair of these anomalies still remains high. MATERIAL AND METHOD: We retrospectively analyzes 27 surgically treated patients with esophageal atresia and tracheoesophageal fistula at Dong-A University Hospital between January 1992 and March 1997. RESULT: There were 21 male and 6 female patients. Mean birth weight was 2.62+/-.385 kg(2.0~3.4 kg). Twenty- four(88.9%) had esophageal atresia with distal tracheoesophageal fistula, and 3(11.1%) had pure esophageal atresia. Four(14.8%) infants were allocated to Waterston risk group A, 18(66.7%) to group B, and 5(18.5%) to group C. In eighteen(66.7%) infants with associated anomalies, cardiovascular anomalies were the most common. Three had a gap length of 3.5 cm or greater(ultra-long gap) between esophageal segments, 7 had 2.0 to 3.5 cm(long gap), 8 had 1.0 to 2.0 cm(medium gap), and 9 had 1 cm or less(short gap) gap length. Among 27 neonates, 3 cases underwent staged operation, late colon interposition was done in 2, and all other 24 cases underwent primary esophageal anastomosis. Oerative mortality was 2/27(7.4%). Causes of death included acute renal failure(n=1), empyema from anastomotic leak(n=1), necrotizing enterocolitis(n=1), sepsis(n=1), insulin-dependent diabetus mellitus(n=1 . There were 4 anastomosis- related complications including stricture in 3, leakage in 1. Mortality was related to the gap length(p<.05). CONCLUSION: Although the complication rate associated with surgical repair of these anomalies is high, this does not always implicate the operative mortality. The overall survival can be improved by effective treatment for combined anomalies and intensive postoperatve care.

Atlantoaxial Subluxation due to Psoriatic Arthritis: Case Report

Psoriatic arthritis is a rare inflammatory joint disease associated with radiographic evidence of periarticular bone erosion and sometimes frank joints destruction among psoriatic patients. There have been only a few reports of atlantoaxial subluxation in patients with psoriatic arthritis in the world. The authors report a case of psoriatic arthritis with atlantoaxial subluxation. This 27-year-old man with a three year history of psoriatic skin lesion presented with painful limitation of neck and multiple joint deformities of the hands and feet, etc. We performed combined interspinous and Gallie fusion for the atlantoaxial subluxation and obtained good results of immediate and long term postoperative stability with Philadelphia neck collar only after this procedure.

Trigeminal Neuralgia in a Patient with Osteopetrosis: A Case Report

Osteopetrosis is a rare disease by a generalized increase in skeletal density and by abnormalities of bone modeling secondary to defective osteoclastic function with impairment of bone resorption. The various cranial nerve palsies may occur secondary to bony encroachment on the cranial foramina. The authors report a case of osteopetrosis with trigeminal neuralgia. This 30-year-old woman presented with the recurring attacks of severe lancinating paroxysmal pain on her right face(mandibular division>maxillary division>ophthalmic division) for 10 years and anosmia, both blindness for 20 years. Her foramen ovale and optic canal narrowings were caused by osteopetrosis. The neuralgia was refractory to medical treatment. Percutaneous radio-frequency rhizotomy for trigeminal neuralgia was performed and pain relief have been obtained. She was satisfied with the procedure, even if with facial numbness. In the case of trigeminal neuralgia in young patient without abnormal mass lesion on brain radiologic imaging studies, it is important to investigate the bony abnormalities of skull base. The authors believe that radiofrequency rhizotomy is the first choice of treatment for trigeminal neuralgia caused by the bony abnormalities of skull base such as osteopetrosis.

A Study of Venous Angiomas

The clinical significance of venous angiomas is controversial. Owing to the increased resolution of modern CT scannes and the advent of magnetic resonance imaging(MRI) as well as an increased awareness of these lesions, venous angiomas has been recognized more frequently in routine neuroradiographic examinations. In a retrospective study of 1998 brain MR imaging performed at our institute between April, 1990 and April, 1992, 18 cases of venous angioma were diagnosed. Among them, 13 cases(72.2%) occur supratentorially and 5 cases(27.8%) occur in cerebellum. Their symptoms were headache(7 cases), hemorrhage(4 cases) seizure(3 cases), focal neurological sign(1 case) and no associated symptoms(3 cases). All cases have been managed conservatibely except one case(with massive cerebellar hemorrhage). During follow up period, no significant complications was happened in all cases. Long-term follow up is necessary to develop meaningful recommendations regarding the management of venous angiomas.

"Dural A-V Malformation of Lateral and Sigmoid Sinus Associated with Intracerebral Hematoma" A Successfully Surgical Treated Case: Case Report

Most of dural arteriovenous malformations(AVM's) of lateral and sigmoid sinuses are known to acquired lesions evolving from a previously thrombosed dural sinus. Their clinical symptoms and signs are variable and their natural history is usually that of gradual progression and hence surgery is frequent necessary. The preferred surgical treatment is complete isolation or excision of the lesion. The authors have experienced 1 case of AVM's of lateral and sigmoid dural sinuses associated with intracerebral hematoma which was treated with complete excision of involved sinus with good result.