Acute and Critical Care

Original Articles

Pediatric
Oxygenation Index in the First 24 Hours after the Diagnosis of Acute Respiratory Distress Syndrome as a Surrogate Metric for Risk Stratification in Children: Soo Yeon Kim, Byuhree Kim, Sun Ha Choi, Jong Deok Kim, In Suk Sol, Min Jung Kim, Yoon Hee Kim, Kyung Won Kim, Myung Hyun Sohn, Kyu-Earn Kim; Acute Crit Care. 2018;33(4):222-229. Published online November 29, 2018; DOI: https://doi.org/10.4266/acc.2018.00136

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Background
The diagnosis of pediatric acute respiratory distress syndrome (PARDS) is a pragmatic decision based on the degree of hypoxia at the time of onset. We aimed to determine whether reclassification using oxygenation metrics 24 hours after diagnosis could provide prognostic ability for outcomes in PARDS.
Methods
Two hundred and eighty-eight pediatric patients admitted between January 1, 2010 and January 30, 2017, who met the inclusion criteria for PARDS were retrospectively analyzed. Reclassification based on data measured 24 hours after diagnosis was compared with the initial classification, and changes in pressure parameters and oxygenation were investigated for their prognostic value with respect to mortality.
Results
PARDS severity varied widely in the first 24 hours; 52.4% of patients showed an improvement, 35.4% showed no change, and 12.2% either showed progression of PARDS or died. Multivariate analysis revealed that mortality risk significantly increased for the severe group, based on classification using metrics collected 24 hours after diagnosis (adjusted odds ratio, 26.84; 95% confidence interval [CI], 3.43 to 209.89; P=0.002). Compared to changes in pressure variables (peak inspiratory pressure and driving pressure), changes in oxygenation (arterial partial pressure of oxygen to fraction of inspired oxygen) over the first 24 hours showed statistically better discriminative power for mortality (area under the receiver operating characteristic curve, 0.701; 95% CI, 0.636 to 0.766; P<0.001).
Conclusions
Implementation of reclassification based on oxygenation metrics 24 hours after diagnosis effectively stratified outcomes in PARDS. Progress within the first 24 hours was significantly associated with outcomes in PARDS, and oxygenation response was the most discernable surrogate metric for mortality.

Citations

Citations to this article as recorded by

A single‐center PICU present status survey of pediatric sepsis‐related acute respiratory distress syndrome
Liang Zhou, Shaojun Li, Tian Tang, Xiu Yuan, Liping Tan
Pediatric Pulmonology.2022; 57(9): 2003. CrossRef

CPR/Resuscitation
Validation of Pediatric Index of Mortality 3 for Predicting Mortality among Patients Admitted to a Pediatric Intensive Care Unit: Jae Hwa Jung, In Suk Sol, Min Jung Kim, Yoon Hee Kim, Kyung Won Kim, Myung Hyun Sohn; Acute Crit Care. 2018;33(3):170-177. Published online August 31, 2018; DOI: https://doi.org/10.4266/acc.2018.00150

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Abstract PDF

Background
The objective of this study was to evaluate the usefulness of the newest version of the pediatric index of mortality (PIM) 3 for predicting mortality and validating PIM 3 in Korean children admitted to a single intensive care unit (ICU).
Methods
We enrolled children at least 1 month old but less than 18 years of age who were admitted to the medical ICU between March 2009 and February 2015. Performances of the pediatric risk of mortality (PRISM) III, PIM 2, and PIM 3 were evaluated by assessing the area under the receiver operating characteristic (ROC) curve, conducting the Hosmer-Lemeshow test, and calculating the standardized mortality ratio (SMR).
Results
In total, 503 children were enrolled; the areas under the ROC curve for PRISM III, PIM 2, and PIM 3 were 0.775, 0.796, and 0.826, respectively. The area under the ROC curve was significantly greater for PIM 3 than for PIM 2 (P<0.001) and PRISM III (P=0.016). There were no significant differences in the Hosmer-Lemeshow test results for PRISM III (P=0.498), PIM 2 (P=0.249), and PIM 3 (P=0.337). The SMR calculated using PIM 3 (1.11) was closer to 1 than PIM 2 (0.84).
Conclusions
PIM 3 showed better prediction of the risk of mortality than PIM 2 for the Korean pediatric population admitted in the ICU.

Citations

Citations to this article as recorded by

Clinical Features and Management of Status Epilepticus in the Pediatric Intensive Care Unit
Ekin Soydan, Yigithan Guzin, Sevgi Topal, Gulhan Atakul, Mustafa Colak, Pinar Seven, Ozlem Sarac Sandal, Gokhan Ceylan, Aycan Unalp, Hasan Agin
Pediatric Emergency Care.2023; 39(3): 142. CrossRef
Evaluation of the Performance of PRISM III and PIM II Scores in a Tertiary Pediatric Intensive Care Unit
Büşra Uzunay Gündoğan, Oğuz Dursun, Nazan Ülgen Tekerek, Levent Dönmez
Turkish Journal of Pediatric Emergency and Intensive Care Medicine.2023; 10(1): 8. CrossRef
Incidence and Mortality Trends in Critically Ill Children: A Korean Population-Based Study
Jaeyoung Choi, Esther Park, Ah Young Choi, Meong Hi Son, Joongbum Cho
Journal of Korean Medical Science.2023;[Epub] CrossRef
Internal validation and evaluation of the predictive performance of models based on the PRISM-3 (Pediatric Risk of Mortality) and PIM-3 (Pediatric Index of Mortality) scoring systems for predicting mortality in Pediatric Intensive Care Units (PICUs)
Zahra Rahmatinejad, Fatemeh Rahmatinejad, Majid Sezavar, Fariba Tohidinezhad, Ameen Abu-Hanna, Saeid Eslami
BMC Pediatrics.2022;[Epub] CrossRef
Performance of Pediatric Risk of Mortality III and Pediatric Index of Mortality III Scores in Tertiary Pediatric Intensive Unit in Saudi Arabia
Ahmed S. Alkhalifah, Abdulaziz AlSoqati, Jihad Zahraa
Frontiers in Pediatrics.2022;[Epub] CrossRef
Clinical implications of discrepancies in predicting pediatric mortality between Pediatric Index of Mortality 3 and Pediatric Logistic Organ Dysfunction-2
Eui Jun Lee, Bongjin Lee, You Sun Kim, Yu Hyeon Choi, Young Ho Kwak, June Dong Park
Acute and Critical Care.2022; 37(3): 454. CrossRef
Administrative data in pediatric critical care research—Potential, challenges, and future directions
Nora Bruns, Anna-Lisa Sorg, Ursula Felderhoff-Müser, Christian Dohna-Schwake, Andreas Stang
Frontiers in Pediatrics.2022;[Epub] CrossRef
Development of a machine learning model for predicting pediatric mortality in the early stages of intensive care unit admission
Bongjin Lee, Kyunghoon Kim, Hyejin Hwang, You Sun Kim, Eun Hee Chung, Jong-Seo Yoon, Hwa Jin Cho, June Dong Park
Scientific Reports.2021;[Epub] CrossRef
Meta-Analysis for the Prediction of Mortality Rates in a Pediatric Intensive Care Unit Using Different Scores: PRISM-III/IV, PIM-3, and PELOD-2
Yaping Shen, Juan Jiang
Frontiers in Pediatrics.2021;[Epub] CrossRef
Simplified Pediatric Index of Mortality 3 Score by Explainable Machine Learning Algorithm
Orkun Baloglu, Matthew Nagy, Chidiebere Ezetendu, Samir Q. Latifi, Aziz Nazha
Critical Care Explorations.2021; 3(10): e0561. CrossRef
Performance of Pediatric Index of Mortality in a Tertiary Care PICU in India
Nisha Toteja, Bharat Choudhary, Daisy Khera, Rohit Sasidharan, Prem Prakash Sharma, Kuldeep Singh
Journal of Pediatric Intensive Care.2021;[Epub] CrossRef

Pediatric
Serum Albumin as a Biomarker of Poor Prognosis in the Pediatric Patients in Intensive Care Unit: Young Suh Kim, In Suk Sol, Min Jung Kim, Soo Yeon Kim, Jong Deok Kim, Yoon Hee Kim, Kyung Won Kim, Myung Hyun Sohn, Kyu-Earn Kim; Korean J Crit Care Med. 2017;32(4):347-355. Published online November 30, 2017; DOI: https://doi.org/10.4266/kjccm.2017.00437

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Abstract PDF Supplementary Material

Background
Serum albumin as an indicator of the disease severity and mortality is suggested in adult patients, but its role in pediatric patients has not been established. The objectives of this study are to investigate the albumin level as a biomarker of poor prognosis and to compare it with other mortality predictive indices in children in intensive care unit (ICU).
Methods
Medical records of 431 children admitted to the ICU at Severance Hospital from January 1, 2012 to December 31, 2015 were retrospectively analyzed. Children who expired within 24 hours after ICU admission, children with hepatic or renal failure, and those who received albumin replacement before ICU admission were excluded.
Results
The children with hypoalbuminemia had higher 28-day mortality rate (24.60% vs. 9.28%, P < 0.001), Pediatric Index of Mortality (PIM) 3 score (9.23 vs. 8.36, P < 0.001), Pediatric Risk of Mortality (PRISM) III score (7.0 vs. 5.0, P < 0.001), incidence of septic shock (12% vs. 3%, P < 0.001), C-reactive protein (33.0 mg/L vs. 5.8 mg/L, P < 0.001), delta neutrophil index (2.0% vs. 0.6%, P < 0.001), lactate level (1.6 mmol/L vs. 1.2 mmol/L, P < 0.001) and lower platelet level (206,000/μl vs. 341,000/μl, P < 0.001) compared to the children with normal albumin level. PIM 3 (r = 0.219, P < 0.001) and PRISM III (r = 0.375, P < 0.001) were negatively correlated with serum albumin level, respectively.
Conclusions
Our results highlight that hypoalbuminemia can be a biomarker of poor prognosis including mortality in the children in ICU.

Citations

Citations to this article as recorded by

Prognostic factors and models to predict pediatric sepsis mortality: A scoping review
Irene Yuniar, Cut Nurul Hafifah, Sharfina Fulki Adilla, Arifah Nur Shadrina, Anthony Christian Darmawan, Kholisah Nasution, Respati W. Ranakusuma, Eka Dian Safitri
Frontiers in Pediatrics.2023;[Epub] CrossRef
The association between serum albumin and long length of stay of patients with acute heart failure: A retrospective study based on the MIMIC-IV database
Tao Liu, Haochen Xuan, Lili Wang, Xiaoqun Li, Zhihao Lu, Zhaoxuan Tian, Junhong Chen, Chaofan Wang, Dongye Li, Tongda Xu, Chiara Lazzeri
PLOS ONE.2023; 18(2): e0282289. CrossRef
Pediatric Inflammatory Multisystem Syndrome Temporally Associated With SARS-CoV-2 (PIMS-TS) and Serous Effusions in a Child With Severe Hypoalbuminemia: A Case Report
Zohair El Haddar, Aziza Elouali, Ilham Belga, Maria Rkain, Abdeladim Babakhouya
Cureus.2023;[Epub] CrossRef
Inappropriate empirical antibiotic therapy was an independent risk factor of pediatric persistent S. aureus bloodstream infection
Xingmei Wang, Ziyao Guo, Xi Zhang, Guangli Zhang, Qinyuan Li, Xiaoyin Tian, Dapeng Chen, Zhengxiu Luo
European Journal of Pediatrics.2022; 182(2): 719. CrossRef
Evaluation of models for predicting pediatric fraction unbound in plasma for human health risk assessment
Yejin Esther Yun, Andrea N. Edginton
Journal of Toxicology and Environmental Health, Part A.2021; 84(2): 67. CrossRef
Diabetes Mellitus and Hypertension Increase Risk of Death in Novel Corona Virus Patients Irrespective of Age: a Prospective Observational Study of Co-morbidities and COVID-19 from India
Anirban Gupta, Neelabh Nayan, Ranjith Nair, Krishna Kumar, Aditya Joshi, Shivangi Sharma, Jasdeep Singh, Rajan Kapoor
SN Comprehensive Clinical Medicine.2021; 3(4): 937. CrossRef
Overview of Albumin Physiology and its Role in Pediatric Diseases
Charles B. Chen, Bilasan Hammo, Jessica Barry, Kadakkal Radhakrishnan
Current Gastroenterology Reports.2021;[Epub] CrossRef
The effect of nutritional status on post-operative outcomes in pediatric otolaryngology-head and neck surgery
Jordan Luttrell, Matthew Spence, Hiba Al-Zubeidi, Michael J. Herr, Madhu Mamidala, Anthony Sheyn
International Journal of Pediatric Otorhinolaryngology.2021; 150: 110875. CrossRef

Hematology/Pediatric
Delta Neutrophil Index as a Prognostic Marker in the Pediatric Intensive Care Unit: In Suk Sol, Hyun Bin Park, Min Jung Kim, Seo Hee Yoon, Yoon Hee Kim, Kyung Won Kim, Myung Hyun Sohn, Kyu-Earn Kim; Korean J Crit Care Med. 2016;31(4):351-358. Published online November 30, 2016; DOI: https://doi.org/10.4266/kjccm.2016.00171

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Abstract PDF

Background
The delta neutrophil index (DNI) is a useful marker for diagnosing and predicting the prognosis of sepsis. The purpose of this study was to investigate the usefulness of DNI as a prognostic marker in patients within the pediatric intensive care unit (PICU), as well as its association with other prognostic factors.
Methods
A total of 516 children admitted to Severance Children’s Hospital PICU from December 2009 to February 2015 were analyzed. DNI was measured on the day of PICU admission. Mortality was defined as death within 28 days following PICU admission.
Results
The median value of DNI was 1.2% (interquartile range [IQR] 0-4.3%) in the survivor group and 9.5% (IQR 2.3-20.8%) in the non-survivor group, and the difference was statistically significant (p < 0.001). DNI was significantly positively correlated with ICU scores such as Pediatric Index of Mortality 3 and Pediatric Risk of Mortality III, as well as with C-reactive protein and lactate levels. The area under the receiver operating characteristic curve of DNI for mortality was 0.748 (95% CI: 0.687-0.808) and the cut-off value was 4.95%.
Conclusions
The initial DNI level can be considered a useful indicator for predicting prognosis in PICU patients.

Citations

Citations to this article as recorded by

Performance Comparison of Procalcitonin, Delta Neutrophil Index, C-Reactive Protein, and Serum Amyloid A Levels in Patients with Hematologic Diseases
Jooyoung Cho, Jong-Han Lee, Dong Hyun Lee, Juwon Kim, Young Uh
Diagnostics.2023; 13(7): 1213. CrossRef
Potential and promising marker for serious bacterial infections in children: Delta neutrophil index
Metin Yigit, Aslinur Ozkaya‐Parlakay, Naci Yilmaz, Ozhan Akyol, Belgin Gulhan, Saliha Kanik Yuksek, Basak Yalcin Burhan, Enes K Kilic, Cuneyt Karagol
Journal of Paediatrics and Child Health.2022; 58(9): 1623. CrossRef
Delta Neutrophil Index as a Diagnostic Marker of Neonatal Sepsis
Nuriye Asli Melekoglu, Seyma Yasar, Mehmet Keskin
Journal of Pediatric Infectious Diseases.2021; 16(03): 099. CrossRef
Prognostic value of the delta neutrophil index in pediatric cardiac arrest
Seo Hee Yoon, Eun Ju Lee, Jinae Lee, Moon Kyu Kim, Jong Gyun Ahn
Scientific Reports.2020;[Epub] CrossRef

Editorial

Cardiology/Hematology
Blood Transfusion Strategies in Patients Supported by Extracorporeal Membrane Oxygenation: Yoon Hee Kim; Korean J Crit Care Med. 2015;30(3):139-142. Published online August 31, 2015; DOI: https://doi.org/10.4266/kjccm.2015.30.3.139

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Original Articles

Usefulness of Thrombocytopenia and Changes in Platelet Counts as Prognostic Markers in Pediatric Intensive Care Units: Yoon Hee Kim, Hyun Bin Park, Min Jung Kim, Hwan Soo Kim, Hee Seon Lee, Yoon Ki Han, Kyung Won Kim, Myung Hyun Sohn, Kyu Earn Kim; Korean J Crit Care Med. 2013;28(2):93-100.; DOI: https://doi.org/10.4266/kjccm.2013.28.2.93

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Abstract PDF: BACKGROUND
Thrombocytopenia has been shown to be a useful predictor of mortality in adult intensive care units (ICUs). The aim of this study is to assess whether the level of platelet count at ICU admission and the changes in platelet counts can predict mortality in the pediatric ICU (PICU).
METHODS
Platelet counts were checked daily for at least 4 days in a total of 303 children who were admitted to the ICU. We compared the initial platelet counts and changes in platelet counts between survivors and non-survivors. A multivariable logistic regression model, a receiver operating characteristic curve and a linear mixed model were used.
RESULTS
The initial platelet count was significantly lower in non-survivors when compared to survivors. Multivariate analysis demonstrated that platelet count <120 x 10(9)/L (Odds ratio, 4.913; 95% confidence interval 2.451-9.851; p < 0.0001) was an independent predictor of mortality. In the case of children with thrombocytopenia (<120 x 10(9)/L) at admission to the ICU, the platelet counts increased serially in survivors, whereas non-survivors maintained their decreased platelet counts. In the case of children without thrombocytopenia, the platelet counts decreased most on day 3 in non-survivors.
CONCLUSIONS
At admission to the ICU, thrombocytopenia defined as a platelet count <120 x 10(9)/L can be a useful predictor of mortality in children. In children who had initial thrombocytopenia, the serial increase of platelet counts can be related to increased survival, whereas in children who did not have initial thrombocytopenia, more than a 10% decrease of platelet counts on day 3 can be related to mortality.

Validation of APACHE II Score and Comparison of the Performance of APACHE II and Adjusted APACHE II Models in a Surgical Intensive Care Unit: Hannnah Lee, Eun Young Choi, Yoon Hee Kim; Korean J Crit Care Med. 2011;26(4):232-237.; DOI: https://doi.org/10.4266/kjccm.2011.26.4.232

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Abstract PDF

BACKGROUND
The ability to accurately adjust for the severity of illness in outcome studies of critically ill patients is essential for clinical audits and trials. Several studies have been carried out to validate the acute physiology and chronic health evaluation (APACHE II) score in Korean ICUs. However, few reports have been presented that compare the performance of the APACHE II score and diagnostic category weighted APACHE II models in the surgical ICU population of Korea. The aim of this study was to validate APACHE II and compare the performance of the APACHE II and adjusted APACHE II models for emergency admission in a surgical intensive care unit (SICU) population.
METHODS
A retrospective analysis of the prospective ICU registry was conducted in the SICU between October 2007 and February 2011. Calibration and discrimination were determined by the Hosmer-Lemeshow test and the area under the receiver operating characteristic (AUC) curve from patients.
RESULTS
This study included 854 patients. SICU mortality was 9.4%. For APACHE II and adjusted APACHE II, AUCs were 0.791 and 0.757, respectively. Hosmer and Lemeshow C statistics showed good calibration for APAHCE II and for adjusted APACHE II (p > 0.05).
CONCLUSIONS
The ability of the APACHE II system in predicting group outcome is validated in a surgical ICU population by a receiver operating characteristic curve and logistic regression analysis. Mortality rates predicted using APACHE II exhibited good calibration and moderate discrimination. Diagnostic category weighted adjusted APACHE II did not improve the mortality prediction.

Citations

Citations to this article as recorded by

Acute Physiologic and Chronic Health Examination II and Sequential Organ Failure Assessment Scores for Predicting Outcomes of Out-of-Hospital Cardiac Arrest Patients Treated with Therapeutic Hypothermia
Sung Joon Kim, Yong-Su Lim, Jin Seong Cho, Jin Joo Kim, Won Bin Park, Hyuk Jun Yang
Korean Journal of Critical Care Medicine.2014; 29(4): 288. CrossRef

Randomized Controlled Trial

Post-thoracotomy Analgesia & ICU Length of Stay: Comparison of Thoracic Epidrual Morphine Infusion and Lumbar Epidural Plus Intravenous Morphine Infusion: Seok Hwa Yoon, Jung Hyun Lee, Hee Suk Yoon, Yoon Hee Kim, Myung Hoon Na, Seung Pyung Lim; Korean J Crit Care Med. 2007;22(2):77-82.

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Abstract PDF: BACKGROUND
Length of stay in ICU after thoracotomy is related to postoperative pulmonary function and complication which are affected by postoperative pain. For the post-thoracotomy pain control, epidural morphine is commonly used. Although total dose-requirement for analgesia of lumbar epidural morphine is more than the thoracic, lumbar epidural morphine could be substituted the thoracic. Our study compared the effect of patient controlled analgesia using thoracic epidural morphine (TEA group) and lumbar epidural analgesia with patient controlled intravenous analgesia using morphine (LEA+IV group).
METHODS
Sixty patients were randomly assigned into one of the two groups. The epidural taps were done before the induction. In all the patients morphine 0.2 mg/ml was administered via the epidural catheter at the end of surgery. In TEA group, basal infusion rate was 0.1 mg/hr and bolus dose was 0.02 mg. In LEA+IV group, basal infusion rate of epidural morphine was 0.1 mg/hr, patient controlled intravenous analgesia with morphine started when patients arrived at ICU, and basal infusion rate of intravenous morphine was 1.0 mg/hr and bolus dose was 0.8 mg. Pain score, side effect, postoperative length of stay in ICU and hospital were observed.
RESULTS
There were no significant differences between two groups in pain score, side effects, length of stay in ICU and hospital.
CONCLUSIONS
Lumbar epidural analgesia with patient controlled intravenous analgesia using morphine showed similar postoperative analgesia and length of stay in ICU and hospital compared to thoracic epidural analgesia with morphine, so that can substitute the thoracic epidural analgesia.

Case Reports

A Case of Pulmonary Edema which Developed after Difficult Endotracheal Intubation of Hunter Syndrome: A Case Report: Ha Jin Kim, Seok Hwa Yoon, Yoon Hee Kim, Hee Suk Yoon; Korean J Crit Care Med. 2005;20(2):187-191.

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Abstract PDF: Hunter syndrome is one of the mucopolysaccharidoses, characterized by abnormal accumulation and deposition of mucopolysaccharides in the tissues of several organs which are known to complicate anaesthetic and airway management. We experienced a case of pulmonary edema which developed during induction of general anesthesia of Hunter syndrome after several attempts of intubation and airway obstruction.

A Case of Pulmonary Aspiration during the Anesthetic Induction in the Post Total Gastrectomy Patient: Yoon Hee Kim, Sang Soo Kim, Moon Hee Park, Seok Hwa Yoon; Korean J Crit Care Med. 1998;13(1):85-90.

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Abstract PDF: Pulmonary aspiration of gastric contents is a feared complication of anesthetic procedures. But aspiration of intestinal contents is rare, the influences of the aspirated contents and/or the consequnt events in the airway have not been fully settled in its provacative role for causing an acute pulmonary reaction. We experienced a case of pulmonary aspiration of intestinal content. The patinet who had undergone previous total gastrectomy was planed emergency operation due to intestinal obstructon. Aspiration during anesthetic induction occurred accidentally. Immediate endotracheal intubation and suction were followed. Right chest breathing sound was coarse and then it was getting better. Although supplement of O2 by Y-piece, arterial blood gas analysis of patient revealed pH 7.30, PaCO2 36 mmHg, PaO2 58 mmHg after emegence from anesthesia in the recovery room. Chest X-ray showed the focal air space consolidation in right lower lung and ill defined pulmonary opacity in left mid lung and retrocardiac area. The measured pH of aspiration content was 7.8 and nonpathogenic Gram negative bacilli species were cutured. Frequent suction, encouraging expectoration, antimicrobial agents therapy and O2 supplementation by Y-piece were performed in the ICU. Patient normalized following 24 hrs after the episode of aspiration.

Original Article

The Effects of Lipopolysaccharide on the Reactivity of Isolated Rat Trachea with or without Epithelium: Hyo Chul Shin, Yoon Hee Kim, Dong Sik Hur, Seok Hwa Yoon, Yong Sup Shin, Sae Jin Choi; Korean J Crit Care Med. 1998;13(1):25-32.

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Abstract PDF: BACKGOUND: Gram negative bacterial lipopolysaccharide (LPS) induces increase in the production of nitric oxide (NO), or a related substance derived from L-arginine in the animal tissue. Recent evidence indicates that airway epithelium may secrete NO or a related compound. It has multiple regulatory roles in the airways. In vitro, the effects of lipopolysaccharide (LPS) on the reactivity of rat' tracheal wall with or without epithelium were examined.
METHODS
Tracheas were removed from Sprague Dawley rats. Preparations were mounted for isometric recording in 20ml organ baths at 37degrees C containing Tis-buffered Tyrode solution continuously gassed with 100% O2. Tensions were measured with force displacement transducers and responses were recorded on a polygraph. Cummulative concentration-response curves were constructed for acetylcholine (Ach) in the tracheal strips with or without preincubation of Escherichia coli LPS (100 mcg/ml, 5hrs). And then effects of NO synthase inhibitors and removal of epithelium were examined.
RESULTS
In isolated perfused tracheas preincubated by LPS, both removed epithelium and intact epithelium of rat tracheal rings showed decreased Ach-induced contraction. In intact epithelium group, 10 (-5)M L-NAME (N-nitro-L-arginine methyl ester), 10 (-5)M L-arginine or dexamethasone pretreatment was restored in Ach-induced contraction response. But in the removed epithelium group, Ach-induced contraction was potentiated by L-arginine pretreatment and was not restored by the pretreatment of L-NAME and dexamethasone.
CONCLUSIONS
The results suggest that nitric oxide synthase is induced by endotoxin in the tracheal epithelium, resulting in inhibition of the contractile response.

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