Evidence Of Pneumothorax Research Articles

Use of Video-Assisted Thoracoscopic Surgery (VATS) in the Treatment of Primary Spontaneous Pneumothorax (PSP) in Children.

This study aims to review the primary spontaneous pneumothorax (PSP) patients we have treated and to discuss the results in terms of PSP treatment management and video-assisted thoracoscopic surgery (VATS) use in the light of the literature. The study was designed retrospectively and conducted at a tertiary referral university hospital between January 1, 2015 and May 1, 2021. Patients under the age of 18 years with a diagnosis of pneumothorax (PTX) were included in the study. Medical records were analyzed in terms of clinical characteristics, demographic data, findings from imaging data, procedures performed, and course of the disease at hospital. Patients with no evidence of PTX on radiologic imaging (direct postero-anterior chest X-ray (PACXR) or thoracic computed tomography (TCT)), incomplete medical records for follow-up, history of trauma, and neonatal PTX were excluded from the study. The study was conducted on a total of 98 PTX cases in 69 patients, 61 (88.4%) males and eight (11.6%) females. The ages of the patients ranged between 13 and 17 years with a mean of 16.59 ± 0.95 years. While 48 (49%) PTX cases were treated with tube thoracostomy, 19 (19.4%) were treated with medical follow-up (nonsurgical treatment) and 31 (31.6%) were treated with VATS. A total of 31 VATS procedures were performed on 28 patients. The follow-up period after VATS ranged from tthree to 78 months, with a mean of 31.5 ± 20.3 months and a median of 28 months. Our retrospective study showed that TCT scanning did not provide additional benefit when PSP was detected on PACXR in patients presenting with chest pain and respiratory distress. According to the findings of our study, it was thought that the probability of undergoing an invasive procedure and surgical intervention increased as the percentage of PTX detected in PACXR increased. Tube thoracostomy may be required in a patient with PSP if PTX does not start to decrease and lung expansion does not increase after an average of 60 hours after the decision for medical follow-up, and if PTX is progressive in the follow-up. VATS can be performed on a patient with PSP when lung expansion does not increase after an average of 18 hours after tube thoracostomy, when PTX progresses, when air leakage continues for more than 10 days despite increased lung expansion, and when recurrent PTX occurs.

The effectiveness of chest T-tube drainage in uniportal video-assisted thoracic surgery.

Uniportal incision located at 4th or 5th intercostal space represents a problem for the correct drainage of distal areas of pleural cavity. The T-shaped tube can drain both the extremities of pleural space. In this study, we evaluated the effectiveness of T-chest tube compared to classic chest tube after uniportal video-assisted thoracic surgery. We compared the effectiveness of T-tube and classic 28 CH chest drainage after different surgical procedures in uniportal video-assisted thoracic surgery: lobectomies, wedge resections and pleural and mediastinal biopsies. As primary end points, drained effusion and evidence of pneumothorax at postoperative day 1, subcutaneous emphysema, tube kinking, obstruction and necessity of repositioning or postoperative thoracentesis were considered. Pain at 6 and 24 h after surgery, pain at tube removal and mean hospitalization were analysed as secondary end points. A total of 109 patients were selected for the study, 51 included to the T-tube group while the other 58 ones to the control group with classic drainage. Patients with T-tube showed a significantly lower rate of pneumothorax (29.4% vs 63.8%; P < 0.001), tube kinking (5.9% vs 27.6%; P = 0.003) and need of repositioning (2.0% vs 12.1%; P = 0.043). No significant results were obtained in subcutaneous emphysema (P = 0.26), tube obstruction (P = 0.32), drained effusion (P = 0.11) and need of postoperative thoracentesis (P = 0.18). Patients with T-tube complained of <6 h after surgery (P < 0.001). Conversely, T-tube removal was reported to be more painful (P < 0.001). Chest T-tube can achieve significantly lower rate of postoperative pneumothorax, kinking and repositioning with less pain 6 hours after surgery compared to classic tube.

Spontaneous Pneumomediastinum in a Young Gentleman

Spontaneous pneumomediastinum (SPM) is defined as presence of free air or gas in the mediastinum. It may occur in young healthy individuals without serious underlying lung disease. SPM is a rare presentation at the Emergency Department; it typically occurs among tall and thin individuals. We report a case of spontaneous pneumomediastinum in a gentleman who presented with a short history of chest and neck pain after coming back from work. Neck radiograph showed neck subcutaneous emphysema and chest radiograph showed pneumomediastinum with no evidence of pneumothorax or rib fracture.

988 A Case of Cocaine Associated Pneumomediastinum: An Unusual Diagnosis

Abstract Cocaine inhalation is an extremely rare but previously described association of spontaneous pneumomediastinum. We describe an unusual case of a previously well 20-year-old female who presented with a five-day history of central, pleuritic chest pain beginning one week after last cocaine inhalation. Blood tests were within the normal limits except for a positive d-dimer. Clinical examination was unremarkable, and a chest X-ray appeared grossly normal. A CT pulmonary angiogram revealed an extensive pneumomediastinum extending into the soft tissues of the neck and down to the peri-oesophageal region at the hiatus, without evidence of pneumothorax. The lungs and oesophagus appeared intact. The patient was admitted for observation and discharged within 48 hours. There is limited literature on this phenomenon, but almost all previous case reports suggest a benign, self-limiting course and resolution of radiological findings within 30 days. Invasive procedures are only considered if there is suspicion of oesophageal rupture or bronchial tree laceration. Spontaneous pneumomediastinum associated with cocaine inhalation is a relatively benign but uncommon condition with a predictable clinical course.

SPONTANEOUS SUBCUTANEOUS EMPHYSEMA AND PNEUMOMEDIASTINUM WITH PROGRESSION TO PNEUMORETROPERITONEUM AS A RARE COMPLICATION OF COVID-19 PNEUMONIA

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Spontaneous pneumothorax, pneumomediastinum, and subcutaneous emphysema have been described as rare life-threatening complications of COVID-19. Reports of pneumoperitoneum or pneumoretroperitoneum are extremely rare. We present a patient with COVID-19 pneumonia who developed spontaneous pneumomediastinum and subcutaneous emphysema with subsequent progression to pneumoretroperitoneum, without evidence of pneumothorax. CASE PRESENTATION: A 61 year old man with HIV and Addison's disease presented to the emergency department with worsening dyspnea, cough, and diarrhea. On admission, his oxygen saturation was 80% on room air, and he had diffuse bilateral lung rhonchi. Nasopharyngeal swab was positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Chest x-ray showed bilateral interstitial opacities. He was treated with dexamethasone, remdesivir, enoxaparin and supplemental oxygen. On hospital day three, he developed worsening hypoxia with pO2 of 41mmHg on 15L non-rebreather oxygen. He was transferred to the intensive care unit (ICU) and placed on non-invasive positive pressure ventilation but was quickly weaned to high-flow oxygen. On hospital day 17, he developed worsening hypoxia and reported neck swelling and tenderness. Computed tomography (CT) of the neck and chest confirmed extensive subcutaneous emphysema and pneumomediastinum and diffuse granular lung opacities without any normally aerated lung parenchyma, without evidence of pneumothorax. He was placed on mechanical ventilation after failing non-invasive positive pressure ventilation. Despite supportive care and lung protective ventilation, he remained hypoxic with worsening subcutaneous emphysema. CT of the chest, abdomen and pelvis showed development of pneumoperitoneum and pneumoretroperitoneum. Due to the patient's refractory hypoxia with progression to multi-system organ failure, his family opted for compassionate extubation and he expired on hospital day 34. DISCUSSION: Common causes of pneumoretroperitoneum include perforated viscous or iatrogenic introduction of air. As this patient had neither surgical procedures or evidence of perforation, his pneumoretroperitoneum was likely due to prolonged positive end expiratory pressure (PEEP) in setting of acute respiratory distress syndrome due to COVID-19. Mechanical ventilation likely acted as a shearing force intensifying air leak into the mediastinum which tracked inferiorly into the retroperitoneum. CONCLUSIONS: In conclusion, pneumomediastinum is a possible complication of COVID-19 pneumonia that can progress to pneumoretroperitoneum despite lung protective ventilation causing acute decompensation that can worsen patient prognosis. REFERENCE #1: Salehi, S., Abedi, A., Balakrishnan, S., & Gholamrezanezhad, A. (2020). Coronavirus Disease 2019 (COVID-19): A Systematic Review of Imaging Findings in 919 Patients. AJR. American journal of roentgenology, 215(1), 87–93. https://doi.org/10.2214/AJR.20.23034Zhou, C., Gao, C., Xie, Y., & Xu, M. (2020). COVID-19 with spontaneous pneumomediastinum. The Lancet. Infectious diseases, 20(4), 510. https://doi.org/10.1016/S1473-3099(20)30156-0 REFERENCE #2: Ahmed, A., Mohamed, M., & Ahmed, K. (2021). Severe COVID-19 Pneumonia Complicated by Pneumothorax, Pneumomediastinum, and Pneumoperitoneum. The American journal of tropical medicine and hygiene, tpmd210092. Advance online publication. https://doi.org/10.4269/ajtmh.21-0092Hillman K. M. (1983). Pneumoretroperitoneum. Anaesthesia, 38(2), 136–139. https://doi.org/10.1111/j.1365-2044.1983.tb13932. REFERENCE #3: Okamoto, A., Nakao, A., Matsuda, K., Yamada, T., Osako, T., Sakata, H., Yamaguchi, Y., Terashima, M., Iwano, J., & Kotani, J. (2014). Non-surgical pneumoperitoneum associated with mechanical ventilation. Acute medicine & surgery, 1(4), 254–255. https://doi.org/10.1002/ams2.52 DISCLOSURES: No relevant relationships by Christopher Ignatz, source=Web Response No relevant relationships by Bao Nhi Nguyen, source=Web Res onse No relevant relationships by Navitha Ramesh, source=Web Response

Pseudopneumothorax: diagnostic pitfalls

Evidence of pneumothorax on radiograph of the chest without accompanying major respiratory signs is rare. Various artefacts including skin fold, shirt fold, bed sheet fold and medial border of scapula...

Tracheal deviation with phrenic nerve palsy after brachial plexus block

We present a caseof a woman who received a left single-injection supraclavicular brachial plexus block for analgesia to facilitate upper extremity orthopaedic surgery. Before tracheal extubation she desaturated, was noted to have a low tidal volume and reduced left-sided air entry on auscultation of the chest. A chest x-ray taken 1h following tracheal extubation revealed elevation of the left hemidiaphragm and a rightward shift of the trachea and mediastinal structures, with no evidence of pneumothorax. Findings were in-keeping with phrenic nerve palsy complicating the brachial plexus block performed. The patient was asymptomatic and discharged home the next day following repeat chest x-rays. We believe this is the first report of tracheal deviation contralateral to the side of an elevated hemidiaphragm secondary to phrenic nerve palsy from a brachial plexus block.

Continuous positive airway pressure (CPAP) provision with a pediatric helmet for treatment of hypoxemic acute respiratory failure in dogs.

To evaluate arterial blood gas parameters and pulmonary radiography, before and after provision of continuous positive airway pressure (CPAP) via a pediatric helmet in dogs with acute hypoxemic respiratory failure. Single-center, observational study conducted from 2016 to 2017. University teaching hospital. Seventeen dogs presenting with clinical signs compatible with respiratory failure, confirmed by arterial blood gas analyses. For each animal arterial blood samples and thoracic radiographs were performed at arrival (T0 ). Hypoxemic dogs (PaO2 <80mmHg), without evidence of pneumothorax or pleural effusion, received CPAP ventilation via a pediatric Helmet for at least 1 hour. At the end of CPAP ventilation, a second arterial blood gas analysis was performed at room air (T1 ). The F-shunt was also calculated. Respiratory rate, heart rate and rhythm, mean blood pressure, mucosal membrane color, and rectal temperature were recorded. Tolerance to the helmet was evaluated using a predetermined scoring system. Two dogs were excluded from the study for low tolerance to the helmet. In 15 of 17 dogs, a significant difference between T0 and T1 was noted for PaO2 (60.84±3mmHg vs 80.2±5.5mmHg), P(A-a)O2 (52.4±4.4mmHg vs 35.2±6mmHg), PaO2 /FiO2 (289.7±14.3 vs 371±21), and %SO2 (91.3 vs 98.8). In 15 of 17 dogs, the helmet was well tolerated. F-shunt significantly decreased following provision of CPAP (37%; range, 8.4-68% vs 6%; range, -5.6-64.3%). The use of a pediatric helmet appears to be a suitable device for delivery of CPAP in dogs with hypoxemic acute respiratory failure. The device appears to be reasonably tolerated and improved oxygenation in most dogs.

Fentanyl-Induced Chest Wall Rigidity as a Cause of Acute Respiratory Failure in the Intensive Care Unit

We aim to report a case of chest wall rigidity induced by high-dose fentanyl infusion sedation and analgesia in the intensive care unit (ICU) for management of pneumonia and asthma. The patient is an 80-year-old woman, who presented to the hospital with complaints of fever and productive cough with yellowish expectoration of 2 days duration. She also had lethargy over the same time period and had sick contacts in the form of two daughters who both had recently recovered from a “flu-like” illness. She was known to have bronchial asthma treated with seretide 25/250 two puffs ON + PO monteleukast 10 mg ON, hypertension treated with PO losartan 50 mg BD, type 2 diabetes mellitus controlled with PO linagliptin 5 mg OM and a previous right thalamic ischemic stroke 5 years ago for which she was on PO clopidogrel 75 mg OM and PO simvastatin. She developed severe ventilator desynchrony characterized by dramatic sudden onset of severe hypercarbia, severely decreased pulmonary compliance and episodic breath holding. She was empirically treated for asthma exacerbation and treated with steroids, bronchodilators and manual ventilation but despite doing so during this episode the patient failed to respond. The patient was clinically evaluated and dynamic hyperinflation was excluded as a cause of the respiratory failure. There was no evidence of pneumothorax and worsening pneumonia. Considerations of insufficient sedation and analgesia led to deepening sedation and analgesia without good response. Ventilation was dramatically improved after small doses of neuromuscular relaxation. This cycle was repeated many times. The patient was kept on high-dose propofol and fentanyl, but there were repeated cycles of sudden persistent severe hypercarbia, severely decreased pulmonary compliance and episodic breath holding. Eventually a suspicion of fentanyl-induced chest wall rigidity was made after excluding causes of airway resistance and reduction in pulmonary compliance. Gradual reduction in fentanyl infusion was associated with a reduction of episodes of reduced lung compliance and improvement in ventilation. Fentanyl is often used for analgesia and sedation in the ICU. It has a good side effect profile but it is not without harm. High doses of fentanyl can lead to dramatic worsening of respiratory mechanics that may be life threatening. Fentanyl-induced chest wall rigidity is an important side effect that needs to be considered in the differential diagnosis of respiratory failure in the ICU. J Med Cases. 2019;10(8):249-252 doi: https://doi.org/10.14740/jmc3351

Spontaneous pneumothorax in cocaine users.

Pneumothorax is one of the respiratory toxic effects of cocaine inhalation. The literature counts several cases, some associated to other respiratory conditions such as pneumomediastinum, haemoptysis and others not requiring surgical treatment. We present a series of nonHIV cocaine-inhaler subjects who underwent video-assisted thoracoscopic surgery (VATS) for isolated spontaneous pneumothorax. Nine subjects, with a mean age of 24 ± 4 years, admitting cocaine inhalation, developed spontaneous pneumothorax and underwent 10 surgical treatments by means of VATS, at our Institution. Previous pneumothorax occurred in six cases episodes ranged from 0 to 5 (mean 1.6 ± 1.6). Chest computed tomography (CT) scan showed abnormalities in seven cases. All subjects underwent lung apicectomy, apical pleurectomy and mechanical pleurodesis. Seven subjects had also bullectomy. In all cases the visceral pleura was partially covered by fibrinous exudate. Histology of the lung showed small foreign body granulomatous inflammation in fibrotic and/or emphysematous pulmonary parenchyma. Relapse of pneumothorax occurred in one subject at 60 days and it was surgically treated. Mean follow-up was 150 ± 38 months (range 120-239). All subjects are now well, with no evidence of pneumothorax. Spontaneous pneumothorax in cocaine-inhaler subjects is a reality of which physicians need to be aware. Chest CT scan might not reveal abnormalities. Macroscopically the lung might presents bullae and/or peculiar visceral pleura. Foreign body granulomas observed in the specimens suggest that the particulate component of inhaled substances can injure the lung. Surgical treatment of the bullous disease and mechanical pleurodesis can provide a long-term follow-up without relapse of pneumothorax.

Knife swallowing ended up with esophagectomy

A 30-years-old male was admitted to surgical emergency department with three-day history of shortness of breath and chest discomfort. He looked healthy, but confused. According to the patient`s statement, he did not have any cronicalillneses or operation, and his medical history was ordinary. His parents told us that his behaviour changed in the last few weeks. He was afebrile with normal vitals, and no associated nausea, vomiting, or fever was present. Lung auscultation showed normal results. After the initial assessment, a chest X-ray was performed (Figure 1), which revealed large, stright edge kitchen knife in the oesophagus. After being presented with a chest X-ray, the patient showed no knowledge, or any memory whatsoever, of swallowing the knife, and even looked a bit surprised. He had firmly refused proposed endoscopic examination, initially offered by a physician. Abdominal CT showed the same, without any evidence of pneumothorax,  pneumomediastinum or pneumoperitoneum (Figure 2). After the initial assessment, and due to the size and position of the knife, it was estimated that endoscopic removal would be too risky, and was therefore decided that it would have been in the best interest of the patient to undergo surgical extraction by esophagectomy (Figures 3 and 4), and three months later esophageal reconstruction with colonic interposition.

Application of PMCT in cases of deaths potentially caused by tension pneumothorax

Introduction The standard autopsy technique allows checking for the presence of air in pleural cavities, but it is very problematic to estimate the volume of gas. So it is hard to evaluate significance of the symptom, especially for considering as the cause of death. Methods Retrospectively, among routinely examined 269 cases with application of PMCT preceding conventional autopsy in 6-month' time (from August 2012)—cases with apparent PMCT signs of tension pneumothorax (a large sided pneumothorax with mediastinal shift to the side and flattening of the hemidiaphragm) were chosen and analyzed in relation to the actual cause of death. Results 73 (about 27% of the total) cases with presence of air in pleural cavity/ies were reported, out of them 11 with features of tension pneumothorax, in 5 very apparent. Cases of tension pneumothorax were not only limited to post-traumatic changes (it seems that most interesting was the case of a single stab wound with the damage of the left lung through the diaphragm, in which PMCTA disclosed lack of significant leakage from bigger blood vessels), one case was related to pneumonia. Conclusion PMCT in contrast to conventional autopsy gives evidence of pneumothorax easily and “repeatedly”, providing opportunities for identification of tension pneumothorax as the cause of death.

Misdiagnosis of pneumothorax by ultrasonography after central venous catheterization in a patient with pleural adhesion

Misdiagnosis of pneumothorax by ultrasonography after central venous catheterization in a patient with pleural adhesion

Diaphragm dysfunction assessed by ultrasonography: Influence on weaning from mechanical ventilation*

To determine the prevalence of diaphragmatic dysfunction diagnosed by M-mode ultrasonography (vertical excursion <10 mm or paradoxic movements) in medical intensive care unit patients and to assess the influence of diaphragmatic dysfunction on weaning outcome. Prospective, observational study. Twenty-eight-bed medical intensive care unit in a university-affiliated hospital. Eighty-eight consecutive patients in the medical intensive care unit who required mechanical ventilation over 48 hrs and met the criteria for a spontaneous breathing trial were assessed. Patients with a history of diaphragmatic or neuromuscular disease or evidence of pneumothorax or pneumomediastinum were excluded. During spontaneous breathing trial, each hemidiaphragm was evaluated by M-mode ultrasonography using the liver and spleen as windows with the patient supine. Rapid shallow breathing index was simultaneously calculated at the bedside. The prevalence of ultrasonographic diaphragmatic dysfunction among the eligible 82 patients was 29% (n = 24). Patients with diaphragmatic dysfunction had longer weaning time (401 [range, 226-612] hrs vs. 90 [range, 24-309] hrs, p < .01) and total ventilation time (576 [range, 374-850] hrs vs. 203 [range, 109-408] hrs, p < .01) than patients without diaphragmatic dysfunction. Patients with diaphragmatic dysfunction also had higher rates of primary (20 of 24 vs. 34 of 58, p < .01) and secondary (ten of 20 vs. ten of 46, p = .01) weaning failures than patients without diaphragmatic dysfunction. The area under the receiver operating characteristics curve of ultrasonographic criteria in predicting weaning failure was similar to that of rapid shallow breathing index. Using M-mode ultrasonography, diaphragmatic dysfunction was found in a substantial number of medical intensive care unit patients without histories of diaphragmatic disease. Patients with such diaphragmatic dysfunction showed frequent early and delayed weaning failures. Ultrasonography of the diaphragm may be useful in identifying patients at high risk of difficulty weaning.

Chest drainage suction decreases differential pleural pressure after upper lobectomy and has no effect after lower lobectomy☆☆☆

To our knowledge, no reports have been published describing the effect of suction on pleural pressures after different types of lobectomy. Improving knowledge of pleural physiology in the postoperative period could lead to better postoperative care. The aim of this investigation is to evaluate the effect of postoperative suction on inspiratory, expiratory and differential pleural pressures after upper or lower lobectomy. Records of intrapleural pressures from 24 lobectomy patients (operated on in two different institutions) were selected for study. All patients had normal preoperative pulmonary function tests (forced expiratory volume in 1s (FEV1) >80% and forced vital capacity (FVC)/FEV1 >70%), and neither postoperative air leak nor any other postoperative complication. We selected six cases of each type of lobectomy (right upper lobectomy (RUL), right lower lobectomy (RLL), left upper lobectomy (LUL) and left lower lobectomy (LLL)). In three cases of each group, no suction was indicated, while in the other three cases, chest tubes were placed under 15 cm H(2)O suction, according to the standard local perioperative care protocol in each participating centre. Inspiratory and expiratory pleural pressures were measured at 2-min intervals by an electronic device using a DigiVent (Millicore A.B., Sweden) suction chamber. Recording started 5-10h after closing the chest, and included 5 consecutive hours during the first postoperative night, with the patients at rest in 30-45 degrees sitting position. There was no evidence of pneumothorax during the recording time. The influence of lobectomy site (upper or lower) and suction on inspiratory, expiratory and differential pressures were evaluated by Student's t-tests. In the group of cases under no suction, upper lobectomy patients had larger differential pressures (22.6 in upper vs 11.5 cm H(2)O in lower lobectomy cases, p<0.001), differential pressure decreased in patients under suction (9.1 in upper vs 11.1 cm H(2)O in lower lobectomy cases, p<0.001) and the effect was mainly due to a less negative inspiratory pressure. Pleural suction leads to a large decrease of differential pleural pressure after upper pulmonary lobectomy. The influence of this finding on postoperative work of breathing in the early postoperative period remains to be investigated.

Successful Treatment of Invasive Pulmonary Aspergillosis in a Neonatal Foal

Successful Treatment of Invasive Pulmonary Aspergillosis in a Neonatal Foal

Bilateral Pneumothorax With Pneumomediastinum Under Anaesthesia In A Neonate

We are presenting a case of bilateral pneumothorax with pneumomediastinum in a 48 hours old infant, posted for emergency repair of high anorectal malformation under general anaesthesia. Preoperatively there is decrease in air entry on left lung and no evidence of pneumothorax. Room air saturation was 90 to 92 %. After intubation, saturation maintained, 95% to 98% with 100% O2. After 30 minutes of intubation there is acute decrease in saturation to 60%, bag was tight, and impossible to ventilate, followed by bradycardia and arrest. CPR started and baby resuscitated. We suspect barotrauma causing pneumothorax. Bilateral ICD was inserted and CXR taken, showing bilateral pneumothorax and pneumomediastinum. Saturation gradually improved to 100% with 40% FIO2. Child was extubated and CT scan thorax was planned which revealed rupture emphysematous bulla. We want to highlights here that any congenital anomalies, as ano-rectal malformation in this case may associated with multiple other defect. Chest xray may not reveal the diagnosis of emphysematous bulla. Intubation and IPPV may cause rupture of bullae and can leads to pneumothorax. So it is better to do complete investigation .which should include CT of whole body and particularly chest to rule out undiagnosed bulla in lung. Figure 1 Figure 1 (Bilateral Pneumothorax with Pneumomediastinum)

Tangential Gunshot Wound to the Chest Causing Venous Air Embolism: A Case Report and Review

This is a case report of a 53-year-old woman who presented to the Emergency Department after sustaining a tangential gunshot wound to the left anterior chest wall. On arrival, the patient was somnolent, hypotensive, hypoxic, and had impaired speech. The patient's cardiopulmonary status stabilized quickly after fluid resuscitation and supplemental oxygen. Because the initial chest radiograph revealed only mild vascular congestion without traumatic injuries, a computed tomography angiogram of the chest was subsequently obtained, which showed air within the right ventricle and pulmonary arteries. Significant bilateral pulmonary infiltrates were also noted without evidence of pneumothorax, penetrating lung, or vascular injuries. There are numerous case reports of venous air embolism (VAE) after penetrating neck, chest, and abdominal injuries, surgical procedures, or secondary to unintentional air injection through venous catheters. Due to the wide range of neurological and cardiopulmonary clinical presentations, the non-specific signs and symptoms of VAE may frequently be attributed to other causes, especially in the setting of trauma. An overview of the pathophysiology, clinical presentation, diagnosis, and treatment of VAE is presented, with emphasis on diagnostic imaging modalities.

Pneumopericardium after pericardiocentesis

A 30-year-old woman with an upper respiratory tract infection presented with acute shortness of breath, hypotension and muffled heart sounds. The echocardiogram revealed a structurally normal heart with a large pericardial effusion with collapse of the right atrium for which a pericardial drain was inserted percutaneously and 600 ml of serous fluid was drained with immediate improvement of hemodynamic parameters. The chest X-ray (Fig. 1) 3 h later showed clear lungs and wide separation of the pericardium from the heart suggesting pneumopericardium (arrows) without evidence of pneumothorax which spontaneously resolved the following days. Further recovery was uneventful. Pneumopericardium is a rare complication of pericardiocentesis that occurs as a result of direct pleuro-pericardial communication. Air surrounding the heart shadow within the pericardium which does not extend beyond the reflection of the aorta and pulmonary artery on chest X-ray is diagnostic.

Accuracy of Transthoracic Sonography in Detection of Pneumothorax After Sonographically Guided Lung Biopsy: Prospective Comparison with Chest Radiography

The purpose of this study was to prospectively evaluate the accuracy of transthoracic sonography in the detection of pneumothorax after transthoracic sonographically guided lung biopsy. Transthoracic sonography was performed on 285 patients after transthoracic sonographically guided lung biopsy. Disappearance of the sliding lung and comettail artifacts and appearance of reverberation artifacts were considered evidence of pneumothorax. Upright chest radiography was performed within 30 minutes of transthoracic sonography. If a discrepancy between transthoracic sonographic and chest radiographic findings occurred, CT was performed. When it was diagnosed, pneumothorax was sonographically monitored. After visualization of resolution of pneumothorax, chest radiography was performed to confirm the resolution. Pneumothorax occurred in eight (2.8%) of the patients. Transthoracic sonography depicted all cases of pneumothorax and excluded pneumothorax in the other cases. Chest radiography did not depict one case of pneumothorax, which was confirmed on CT. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were all 100% for transthoracic sonography and 87.5%, 100%, 100%, 99.6%, and 99.6%, respectively, for chest radiography. The 95% confidence intervals (CI) of the differences in sensitivity, negative predictive value, and overall accuracy were -10% to 35%, -0.1 to 0.9%, and -0.1 to 0.9%. Transthoracic sonographic visualization of resolution of pneumothorax was always confirmed with chest radiography. These preliminary results suggest that transthoracic sonography is as effective as chest radiography in the detection of pneumothorax after transthoracic sonographically guided lung biopsy and may become the method of choice for excluding, diagnosing, and monitoring pneumothorax after transthoracic sonographically guided biopsy. Chest radiography may be needed only for assessment of the extent of pulmonary collapse after transthoracic sonographic diagnosis of pneumothorax or in the presence of discrepancy between transthoracic sonographic findings and clinical presentation.