Letter to the Editor
A Comment on the Pulmonary Contusion Model Sezai Çubuk1
Orhan Yücel2
1 Department of Thoracic Surgery, Gata Medical Faculty,
Ankara, Turkey 2 Department of Thoracic Surgery, Gata Haydarpasa Teaching Hospital, Istanbul, Turkey
Address for correspondence Sezai Çubuk, MD, Department of Thoracic Surgery, Gata Medical Faculty, Ankara, Turkey (e-mail: [email protected]).
Thorac Cardiovasc Surg
received January 15, 2015 accepted January 22, 2015
study was performed, it should be mentioned. As a result, we think that the first part of the article should have been detailed.
Conflict of Interest None declared.
References 1 Boybeyi O, Bakar B, Aslan MK, Atasoy P, Kisa U, Soyer T. Evaluation
of dimethyl sulfoxide and dexamethasone on pulmonary contusion in experimental blunt thoracic trauma. Thorac Cardiovasc Surg 2014;62(8):710–715 2 Yücel O, Genç O, Özcan A, et al. The blunt thoracic trauma model on rat lungs: an experimental study. Gulhane Med J. 2008;50(4): 249–252 3 Raghavendran K, Davidson BA, Helinski JD, et al. A rat model for isolated bilateral lung contusion from blunt chest trauma. Anesth Analg 2005;101(5):1482–1489
© Georg Thieme Verlag KG Stuttgart · New York
DOI http://dx.doi.org/ 10.1055/s-0035-1547351. ISSN 0171-6425.
Downloaded by: University of Florida. Copyrighted material.
We read the article of Boybeyi et al.1 The authors studied the effect of dimethyl sulfoxide and dexamethasone on a contused lung with a rat model. They declared using 0.5 kg weight and 0.4 m height for pulmonary contusion. We think that falling 500 g weight from 40 cm is too much for the rats. We also have a model for blunt thoracic trauma identical to theirs.2 In our model, we used a 90-cm pipe and three types of weights: 40, 70, 100 g. With these weights, we gained light, moderate, and severe thoracic blunt trauma. In their model, Raghavendran et al3 used 0.3 kg weight and height combinations (1.80–2.70 J) to gain bilateral lung contusion. They positioned the rat in supine position and used a platform above the rat. Therefore, higher trauma intensities can be used with a platform to the anterior chest wall. As we understand from the text, this study has two parts: the first part is the trauma part and the second part is the evaluation of the substances. To gain reliable results, the first part must be established well. We think that a control group for the trauma should have been established. If a preliminary
Letter to the Editor
Reply by the Authors of the Original Article Ozlem Boybeyi1 Tutku Soyer1
University, Kırıkkale, Turkey
We read the comment and the related article of Yucel et al.1 They studied an experimental blunt chest trauma model and claimed that the weight and height used in our experimental model was too much for rats. In our study, we conducted an experimental study to evaluate the effect of dimethylsulfoxide (DMSO) and dexamethasone to lung injury occurred secondary to blunt chest trauma in rat model. Therefore, we had to use a previously proven experimental model. We used modified version of the model of Raghavendran et al.2 Raghavendran used 0.3 kg weight from different height to get different impact energies in between 1.80 and 2.70 J (E ¼ m G h). They reported that the impact energy should not exceed 2.45 J to prevent fatal complications. However, they performed the experiments on a platform with a cardioprotective sheet to have bilateral contusion. Because we aimed to get unilateral contusion model, we dropped the weight on the right hemithorax to prevent cardiac complications. We dropped 0.5 kg weight from 40 cm height to get 1.96-J impact energy (E ¼ 0.5 9.8 0.4 ¼ 1.96 J), which was reported as the most appropriate energy to get lung injury with lower mortality by Ozel et al.3 We have already had a control group in our study. We did not perform chest trauma in control group animals and compared the trauma group (Sham) with that control group. Macroscopic and histopathological findings revealed significant difference in SG compared with CG revealing that our
Thoracic and Cardiovascular Surgeon
Address for correspondence: Ozlem Boybeyi, MD, Department of Pediatric Surgery, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey (e-mail: [email protected]).
model was able to cause lung injury. Therefore, we think that first part of our study was appropriate with reliable results. All these data were given in the manuscript in detail. Additionally, we read the article given in the commentary.1 We realized that the calculated impact energy in Table 1 was less than the total energy obtained by E ¼ m g h formula and they should be 0.40 J for 40 g, 0.68 J for 70 g, and 0.98 J for 100 g when dropped from 1 m height. Therefore, we suggest that their experimental model generates less energy than the study they cited.2,3 However, experimental model for blunt thoracic trauma can be obtained with less impact energy; we preferred the most common experimental model to compare our results with the previous studies.
References 1 Yücel O, Genç O, Özcan A, et al. The blunt thoracic trauma model on
rat lungs: an experimental study. Gulhane Med J 2008;50(4): 249–252 2 Raghavendran K, Davidson BA, Helinski JD, et al. A rat model for isolated bilateral lung contusion from blunt chest trauma. Anesth Analg 2005;101(5):1482–1489 3 Özel ŞK, Özel HB, Colakoğlu N, Ilhan N, Arslan N, Ozan E. Protective effect of the thoracic cage on parenchyma in response to trauma direction in blunt thoracic trauma: an experimental study. Ulus Travma Acil Cerrahi Derg 2010;16(4):287–292
Downloaded by: University of Florida. Copyrighted material.
1 Department of Pediatric Surgery, Medical Faculty, Kırıkkale
A Comment on the Pulmonary Contusion Model Sezai Çubuk1
Orhan Yücel2
1 Department of Thoracic Surgery, Gata Medical Faculty,
Ankara, Turkey 2 Department of Thoracic Surgery, Gata Haydarpasa Teaching Hospital, Istanbul, Turkey
Address for correspondence Sezai Çubuk, MD, Department of Thoracic Surgery, Gata Medical Faculty, Ankara, Turkey (e-mail: [email protected]).
Thorac Cardiovasc Surg
received January 15, 2015 accepted January 22, 2015
study was performed, it should be mentioned. As a result, we think that the first part of the article should have been detailed.
Conflict of Interest None declared.
References 1 Boybeyi O, Bakar B, Aslan MK, Atasoy P, Kisa U, Soyer T. Evaluation
of dimethyl sulfoxide and dexamethasone on pulmonary contusion in experimental blunt thoracic trauma. Thorac Cardiovasc Surg 2014;62(8):710–715 2 Yücel O, Genç O, Özcan A, et al. The blunt thoracic trauma model on rat lungs: an experimental study. Gulhane Med J. 2008;50(4): 249–252 3 Raghavendran K, Davidson BA, Helinski JD, et al. A rat model for isolated bilateral lung contusion from blunt chest trauma. Anesth Analg 2005;101(5):1482–1489
© Georg Thieme Verlag KG Stuttgart · New York
DOI http://dx.doi.org/ 10.1055/s-0035-1547351. ISSN 0171-6425.
Downloaded by: University of Florida. Copyrighted material.
We read the article of Boybeyi et al.1 The authors studied the effect of dimethyl sulfoxide and dexamethasone on a contused lung with a rat model. They declared using 0.5 kg weight and 0.4 m height for pulmonary contusion. We think that falling 500 g weight from 40 cm is too much for the rats. We also have a model for blunt thoracic trauma identical to theirs.2 In our model, we used a 90-cm pipe and three types of weights: 40, 70, 100 g. With these weights, we gained light, moderate, and severe thoracic blunt trauma. In their model, Raghavendran et al3 used 0.3 kg weight and height combinations (1.80–2.70 J) to gain bilateral lung contusion. They positioned the rat in supine position and used a platform above the rat. Therefore, higher trauma intensities can be used with a platform to the anterior chest wall. As we understand from the text, this study has two parts: the first part is the trauma part and the second part is the evaluation of the substances. To gain reliable results, the first part must be established well. We think that a control group for the trauma should have been established. If a preliminary
Letter to the Editor
Reply by the Authors of the Original Article Ozlem Boybeyi1 Tutku Soyer1
University, Kırıkkale, Turkey
We read the comment and the related article of Yucel et al.1 They studied an experimental blunt chest trauma model and claimed that the weight and height used in our experimental model was too much for rats. In our study, we conducted an experimental study to evaluate the effect of dimethylsulfoxide (DMSO) and dexamethasone to lung injury occurred secondary to blunt chest trauma in rat model. Therefore, we had to use a previously proven experimental model. We used modified version of the model of Raghavendran et al.2 Raghavendran used 0.3 kg weight from different height to get different impact energies in between 1.80 and 2.70 J (E ¼ m G h). They reported that the impact energy should not exceed 2.45 J to prevent fatal complications. However, they performed the experiments on a platform with a cardioprotective sheet to have bilateral contusion. Because we aimed to get unilateral contusion model, we dropped the weight on the right hemithorax to prevent cardiac complications. We dropped 0.5 kg weight from 40 cm height to get 1.96-J impact energy (E ¼ 0.5 9.8 0.4 ¼ 1.96 J), which was reported as the most appropriate energy to get lung injury with lower mortality by Ozel et al.3 We have already had a control group in our study. We did not perform chest trauma in control group animals and compared the trauma group (Sham) with that control group. Macroscopic and histopathological findings revealed significant difference in SG compared with CG revealing that our
Thoracic and Cardiovascular Surgeon
Address for correspondence: Ozlem Boybeyi, MD, Department of Pediatric Surgery, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey (e-mail: [email protected]).
model was able to cause lung injury. Therefore, we think that first part of our study was appropriate with reliable results. All these data were given in the manuscript in detail. Additionally, we read the article given in the commentary.1 We realized that the calculated impact energy in Table 1 was less than the total energy obtained by E ¼ m g h formula and they should be 0.40 J for 40 g, 0.68 J for 70 g, and 0.98 J for 100 g when dropped from 1 m height. Therefore, we suggest that their experimental model generates less energy than the study they cited.2,3 However, experimental model for blunt thoracic trauma can be obtained with less impact energy; we preferred the most common experimental model to compare our results with the previous studies.
References 1 Yücel O, Genç O, Özcan A, et al. The blunt thoracic trauma model on
rat lungs: an experimental study. Gulhane Med J 2008;50(4): 249–252 2 Raghavendran K, Davidson BA, Helinski JD, et al. A rat model for isolated bilateral lung contusion from blunt chest trauma. Anesth Analg 2005;101(5):1482–1489 3 Özel ŞK, Özel HB, Colakoğlu N, Ilhan N, Arslan N, Ozan E. Protective effect of the thoracic cage on parenchyma in response to trauma direction in blunt thoracic trauma: an experimental study. Ulus Travma Acil Cerrahi Derg 2010;16(4):287–292
Downloaded by: University of Florida. Copyrighted material.
1 Department of Pediatric Surgery, Medical Faculty, Kırıkkale
