- Email: [email protected]
Response to: “If you see the contusion, there is no pneumothorax”
Correspondence
107 Sara Sher MD Anesthesia and Critical Care Department Fondazione Policlinico Mangiagalli e Regina Elena-IRCCS Milano, Italy Roberto Copetti MD Emergency Department S. Antonio Abate General Hospital Tolmezzo, Udine, Italy doi:10.1016/j.ajem.2009.09.003
References
Fig. 2 A small retroparietal anterior air collection (between the 2 arrows), a “double lung point,” covers all possible pleural artifacts, including power Doppler movement.
B-lines is a pattern characteristic of early contusion, present in 94% of cases [4]. Rocco et al [5] refer to a sensitivity of echography of 84% toward diagnosis of lung contusion. If we hypothesize that, in case of lung contusion, ultrasonographic lung scanning will rarely show a normal lung pattern and that presence of air in the pleural space acts as a specular reflector [6] that covers all possible underlying artifacts, evidence of comet tail artifacts, as in lung contusion, will exclude, by itself, the possibility of PNX. This appears evident in the study of a lung point shown in Fig. 1. Fig. 2 shows the presence of a double lung point own to a small anterior air bubble. This figure is also very explicative as it shows how all lung artifacts, and even the possibility of seeing Doppler movement, are hidden by the presence of an air bubble that displaces the visceral pleura from which lung artifacts have origin. It is thus clear that, whenever air is present, all artifacts created by underlying parenchymal disease will be masked. It is possible that lung sliding in a contused lung be reduced, for the smaller respiratory excursions and the reduced lung compliance [7], but this will not represent a problem in the diagnosis of PNX if all other accessory signs are evaluated—in particular, the echographic signs of lung contusion, which themselves exclude PNX. What the clinician will instead have to worry about is the possibility of the appearance of an echographic interstitial syndrome after PNX drainage, as this could be a sign of the presence of a lung contusion that was initially masked by the pleural air. Gino Soldati MD Emergency Department Valle del Serchio General Hospital Castelnuovo Garfagnana, Lucca, Italy E-mail address: [email protected]
[1] Platz E, Cydulka R, Werner S, et al. The effect of pulmonary contusions on lung sliding during bedside ultrasound. Am J Emerg Med 2009;27: 363-5. [2] Lichtenstein D, Mezière G, Biderman P, et al. The lung point: An ultrasound sign specific to pneumothorax. Intensive Care Med 2000;26: 1434-40. [3] Lichtenstein D, Meziere G, Biderman P, et al. The comet-tail artifact. An ultrasound sign of alveolar interstitial syndrome. Am J Respir Crit Care Med 1997;156:1640-6. [4] Soldati G, Testa A, Silva FR, et al. Chest ultrasonography in lung contusion. Chest 2006;130:533-8. [5] Rocco M, Carbone I, Morelli A, et al. Diagnostic accuracy of bedside ultrasonography in the ICU: feasibility of detecting pulmonary effusion and lung contusion in patients on respiratory support after severe blunt thoracic trauma. Acta Anaesthesiol Scand 2008;52:776-84. [6] Soldati G, Copetti R, Sher S. Sonographic interstitial syndrome: the sound of lung water. J Ultrasound Med 2009;28:163-74. [7] Copetti R, Soldati G, Copetti P. Chest sonography: a useful tool to differentiate acute cardiogenic pulmonary edema from acute respiratory distress syndrome. Cardiovasc Ultrasound 2008;29:16.
Response to: “If you see the contusion, there is no pneumothorax” To the Editor, We would like to thank the readers for their insightful comments. We agree that a combination of several sonographic findings and techniques, such as lung sliding, comet tails, lung point, M-mode, power Doppler, and others, may be needed to confidently rule out the presence of a pneumothorax. However, evaluating these combinations was not the objective of our study. Our study was designed to specifically evaluate whether lung sliding is affected by the presence of pulmonary contusions. This question is of interest because many clinicians consider lung sliding the mainstay of the sonographic evaluation of pneumothorax. The clinical problem was briefly addressed by Blaivas and colleagues [1] in 2005, which raised the concern that the presence of pulmonary contusions may affect lung sliding and limit the usefulness of ultrasound to exclude a pneumothorax under these circumstances. Further investigations are needed to clarify which sonographic technique(s) and artifacts allow for the highest
108
Correspondence
sensitivity and specificity in the evaluation of patients with suspected pneumothorax, especially in those patients who do not have a normal pleural interface. Elke Platz MD, RDMS Department of Emergency Medicine Brigham and Women’s Hospital Boston, MA 02115, USA Harvard Medical School Boston, MA, USA E-mail address: [email protected] Rita Cydulka MD, MS Sandra Werner MD, RDMS Department of Emergency Medicine MetroHealth Medical Center Cleveland, OH, USA Case Western Reserve University Cleveland, OH, USA E-mail addresses: [email protected] [email protected] Jessica Resnick MD, RDMS Department of Emergency Medicine Akron General Hospital Akron, OH, USA E-mail address: [email protected] Robert Jones DO, RDMS Department of Emergency Medicine MetroHealth Medical Center Cleveland, OH, USA Case Western Reserve University Cleveland, OH, USA E-mail address: [email protected] doi:10.1016/j.ajem.2009.09.004
Reference [1] Blaivas M, Lyon M, Duggal S. A prospective comparison of supine chest radiography and bedside ultrasound for the diagnosis of traumatic pneumothorax. Acad Emerg Med 2005;12(9):844-9.
Issues on percutaneous feeding tube replacement To the Editor, I read with interest the publication by Jacobson et al [1] in the recent issue of the journal on confirmatory radiography post-percutaneous feeding tube (PFT) replacement. They highlighted 2 important issues on PFT replacement; the role of radiography and the importance of tract trauma. Overall, they did not show any impact of routine post replacement
radiography. Like many other centers, we do not use radiography at all. In our setting, the only time radiography had been used post PFT replacement, tube misplacement was missed. This patient had a balloon-type PFT replacement done in the emergency department and injected contrast was seen entering the small bowel. The position was reported to be correct. It turned out that the balloon part had been inserted through the pylorus resulting in gastric outlet obstruction [2]. Currently, there is still no convincing evidence in the literature to support the routine use of radiography. The second issue highlighted, in my opinion, is more relevant. It would be more prudent to avoid further trauma to the already traumatized tract by avoiding repeated manipulation and dilatation of the tract, especially the immature tracts. In Jacobson's study, most of their patients had tract trauma secondary to accidental PFT extraction and 10% of their patients had tract dilatation. In the 4 complicated cases, risk factors for tract disruptions were present, including 3 immature tracts. In my practice, I usually assess the tract for possibility of immediate replacement with the intended PFT (Cook 24F balloon replacement PEG). If the tract is immature or has narrowed because of late presentations, I would recommend placing a small urinary catheter (12F-18F) into the stomach. The catheter will serve as a temporary feeding tube and a dilator. The catheter can be replaced with larger catheter and this can be done within hours to weeks. After 2 to 3 exchanges, the tract usually will have opened up to allow easy placement of a 24F PFT (24F). To date, we have not encountered any problems with this practice. Therefore, it is probably more important and costeffective to avoid further trauma that may result in complication. Finally, there were many other important details that were not presented that might be important in the understanding the true impact of PFT replacement with or without radiography. Details on the types of displaced PFT (balloon or mushroom type internal bolster), details on level of difficulty with replacement, the number of attempts required, sizes of the replacement PFT used, and the level of expertise of those who did the replacement are all important. Vui Heng Chong MRCP, FAMS Gastroenterology Unit Department of Medicine Raja Isteri Pengiran Anak Saleha (RIPAS) Hospital Bandar Seri Begawan BA 1710, Brunei Darussalam E-mail address: [email protected] doi:10.1016/j.ajem.2009.09.023
References [1] Jacobson G, Brokish PA, Wrenn K. Percutaneous feeding tube replacement in the ED—are confirmatory x-rays necessary? Am J Emerg Med 2009;27:519-24. [2] Chong VH. Gastric outlet obstruction caused by gastrostomy tube balloon. Indian J Gastroenterol 2004;23:80.
107 Sara Sher MD Anesthesia and Critical Care Department Fondazione Policlinico Mangiagalli e Regina Elena-IRCCS Milano, Italy Roberto Copetti MD Emergency Department S. Antonio Abate General Hospital Tolmezzo, Udine, Italy doi:10.1016/j.ajem.2009.09.003
References
Fig. 2 A small retroparietal anterior air collection (between the 2 arrows), a “double lung point,” covers all possible pleural artifacts, including power Doppler movement.
B-lines is a pattern characteristic of early contusion, present in 94% of cases [4]. Rocco et al [5] refer to a sensitivity of echography of 84% toward diagnosis of lung contusion. If we hypothesize that, in case of lung contusion, ultrasonographic lung scanning will rarely show a normal lung pattern and that presence of air in the pleural space acts as a specular reflector [6] that covers all possible underlying artifacts, evidence of comet tail artifacts, as in lung contusion, will exclude, by itself, the possibility of PNX. This appears evident in the study of a lung point shown in Fig. 1. Fig. 2 shows the presence of a double lung point own to a small anterior air bubble. This figure is also very explicative as it shows how all lung artifacts, and even the possibility of seeing Doppler movement, are hidden by the presence of an air bubble that displaces the visceral pleura from which lung artifacts have origin. It is thus clear that, whenever air is present, all artifacts created by underlying parenchymal disease will be masked. It is possible that lung sliding in a contused lung be reduced, for the smaller respiratory excursions and the reduced lung compliance [7], but this will not represent a problem in the diagnosis of PNX if all other accessory signs are evaluated—in particular, the echographic signs of lung contusion, which themselves exclude PNX. What the clinician will instead have to worry about is the possibility of the appearance of an echographic interstitial syndrome after PNX drainage, as this could be a sign of the presence of a lung contusion that was initially masked by the pleural air. Gino Soldati MD Emergency Department Valle del Serchio General Hospital Castelnuovo Garfagnana, Lucca, Italy E-mail address: [email protected]
[1] Platz E, Cydulka R, Werner S, et al. The effect of pulmonary contusions on lung sliding during bedside ultrasound. Am J Emerg Med 2009;27: 363-5. [2] Lichtenstein D, Mezière G, Biderman P, et al. The lung point: An ultrasound sign specific to pneumothorax. Intensive Care Med 2000;26: 1434-40. [3] Lichtenstein D, Meziere G, Biderman P, et al. The comet-tail artifact. An ultrasound sign of alveolar interstitial syndrome. Am J Respir Crit Care Med 1997;156:1640-6. [4] Soldati G, Testa A, Silva FR, et al. Chest ultrasonography in lung contusion. Chest 2006;130:533-8. [5] Rocco M, Carbone I, Morelli A, et al. Diagnostic accuracy of bedside ultrasonography in the ICU: feasibility of detecting pulmonary effusion and lung contusion in patients on respiratory support after severe blunt thoracic trauma. Acta Anaesthesiol Scand 2008;52:776-84. [6] Soldati G, Copetti R, Sher S. Sonographic interstitial syndrome: the sound of lung water. J Ultrasound Med 2009;28:163-74. [7] Copetti R, Soldati G, Copetti P. Chest sonography: a useful tool to differentiate acute cardiogenic pulmonary edema from acute respiratory distress syndrome. Cardiovasc Ultrasound 2008;29:16.
Response to: “If you see the contusion, there is no pneumothorax” To the Editor, We would like to thank the readers for their insightful comments. We agree that a combination of several sonographic findings and techniques, such as lung sliding, comet tails, lung point, M-mode, power Doppler, and others, may be needed to confidently rule out the presence of a pneumothorax. However, evaluating these combinations was not the objective of our study. Our study was designed to specifically evaluate whether lung sliding is affected by the presence of pulmonary contusions. This question is of interest because many clinicians consider lung sliding the mainstay of the sonographic evaluation of pneumothorax. The clinical problem was briefly addressed by Blaivas and colleagues [1] in 2005, which raised the concern that the presence of pulmonary contusions may affect lung sliding and limit the usefulness of ultrasound to exclude a pneumothorax under these circumstances. Further investigations are needed to clarify which sonographic technique(s) and artifacts allow for the highest
108
Correspondence
sensitivity and specificity in the evaluation of patients with suspected pneumothorax, especially in those patients who do not have a normal pleural interface. Elke Platz MD, RDMS Department of Emergency Medicine Brigham and Women’s Hospital Boston, MA 02115, USA Harvard Medical School Boston, MA, USA E-mail address: [email protected] Rita Cydulka MD, MS Sandra Werner MD, RDMS Department of Emergency Medicine MetroHealth Medical Center Cleveland, OH, USA Case Western Reserve University Cleveland, OH, USA E-mail addresses: [email protected] [email protected] Jessica Resnick MD, RDMS Department of Emergency Medicine Akron General Hospital Akron, OH, USA E-mail address: [email protected] Robert Jones DO, RDMS Department of Emergency Medicine MetroHealth Medical Center Cleveland, OH, USA Case Western Reserve University Cleveland, OH, USA E-mail address: [email protected] doi:10.1016/j.ajem.2009.09.004
Reference [1] Blaivas M, Lyon M, Duggal S. A prospective comparison of supine chest radiography and bedside ultrasound for the diagnosis of traumatic pneumothorax. Acad Emerg Med 2005;12(9):844-9.
Issues on percutaneous feeding tube replacement To the Editor, I read with interest the publication by Jacobson et al [1] in the recent issue of the journal on confirmatory radiography post-percutaneous feeding tube (PFT) replacement. They highlighted 2 important issues on PFT replacement; the role of radiography and the importance of tract trauma. Overall, they did not show any impact of routine post replacement
radiography. Like many other centers, we do not use radiography at all. In our setting, the only time radiography had been used post PFT replacement, tube misplacement was missed. This patient had a balloon-type PFT replacement done in the emergency department and injected contrast was seen entering the small bowel. The position was reported to be correct. It turned out that the balloon part had been inserted through the pylorus resulting in gastric outlet obstruction [2]. Currently, there is still no convincing evidence in the literature to support the routine use of radiography. The second issue highlighted, in my opinion, is more relevant. It would be more prudent to avoid further trauma to the already traumatized tract by avoiding repeated manipulation and dilatation of the tract, especially the immature tracts. In Jacobson's study, most of their patients had tract trauma secondary to accidental PFT extraction and 10% of their patients had tract dilatation. In the 4 complicated cases, risk factors for tract disruptions were present, including 3 immature tracts. In my practice, I usually assess the tract for possibility of immediate replacement with the intended PFT (Cook 24F balloon replacement PEG). If the tract is immature or has narrowed because of late presentations, I would recommend placing a small urinary catheter (12F-18F) into the stomach. The catheter will serve as a temporary feeding tube and a dilator. The catheter can be replaced with larger catheter and this can be done within hours to weeks. After 2 to 3 exchanges, the tract usually will have opened up to allow easy placement of a 24F PFT (24F). To date, we have not encountered any problems with this practice. Therefore, it is probably more important and costeffective to avoid further trauma that may result in complication. Finally, there were many other important details that were not presented that might be important in the understanding the true impact of PFT replacement with or without radiography. Details on the types of displaced PFT (balloon or mushroom type internal bolster), details on level of difficulty with replacement, the number of attempts required, sizes of the replacement PFT used, and the level of expertise of those who did the replacement are all important. Vui Heng Chong MRCP, FAMS Gastroenterology Unit Department of Medicine Raja Isteri Pengiran Anak Saleha (RIPAS) Hospital Bandar Seri Begawan BA 1710, Brunei Darussalam E-mail address: [email protected] doi:10.1016/j.ajem.2009.09.023
References [1] Jacobson G, Brokish PA, Wrenn K. Percutaneous feeding tube replacement in the ED—are confirmatory x-rays necessary? Am J Emerg Med 2009;27:519-24. [2] Chong VH. Gastric outlet obstruction caused by gastrostomy tube balloon. Indian J Gastroenterol 2004;23:80.