Role of CT in the management of pneumothorax in patients with complex cystic lung disease

Pneumothorax in patients with respiratory failure in ICU

Pneumothorax is not an uncommon occurrence in ICU patients. Barotrauma and iatrogenesis remain the most common causes for pneumothorax in critically ill patients. Patients with underlying lung disease are more prone to develop pneumothorax, especially if they require positive pressure ventilation. A timely diagnosis of pneumothorax is critical as it may evolve into tension physiology. Most occurrences of pneumothoraces are readily diagnosed with a chest X-ray. Tension pneumothorax is a medical emergency, and managed with immediate needle decompression followed by tube thoracostomy. A computed tomography (CT) scan of the chest remains the gold standard for diagnosis; however, getting a CT scan of the chest in a critically ill patient can be challenging. The use of thoracic ultrasound has been emerging and is proven to be superior to chest X-ray in making a diagnosis. The possibility of occult pneumothorax in patients with thoracoabdominal blunt trauma should be kept in mind. Patients with pneumothorax in the ICU should be managed with a tube thoracostomy if they are symptomatic or on mechanical ventilation. The current guidelines recommend a small-bore chest tube as the first line management of pneumothorax. In patients with persistent air leak or whose lungs do not re-expand, a thoracic surgery consultation is recommended. In non-surgical candidates, bronchoscopic interventions or autologous blood patch are other options.

End-Tidal Carbon Dioxide Monitoring for Spontaneous Pneumothorax

Background

Spontaneous pneumothorax should be classified as primary spontaneous pneumothorax (PSP) or secondary spontaneous pneumothorax (SSP) because treatment strategies may differ depending on underlying lung conditions and clinical course. The pulmonary dysfunction can lead to changes in end-tidal carbon dioxide (ETCO₂). The aim of this study was to investigate the difference in ETCO₂ between PSP and SSP.

Methods

This retrospective observational study included adult patients diagnosed with spontaneous pneumothorax in the emergency room from April 2019 to September 2020. We divided patients into PSP and SSP groups and compared ETCO₂ variables between the two groups.

Results

There were 33 (66%) patients in the PSP group and 17 (34%) patients in the SSP group. Initial ETCO₂ was lower in the SSP group than in the PSP group (30 (23–33) vs. 35 (33–38) mmHg, p=0.002). Multivariate analysis revealed that respiratory gas associated with SSP was initial ETCO₂ (OR: 0.824; 95% CI: 0.697–0.974, p=0.023). The optimal cutoff for initial ETCO₂ to detection of SSP was 32 mmHg (area under curve, 0.754), with 76.5% sensitivity and 72.7% specificity.

Conclusion

ETCO₂ monitoring is a reliable noninvasive indicator of differentiating between PSP and SSP. Initial ETCO₂ lower than 32 mmHg is a predictor of SSP.

Pneumothorax in cystic fibrosis: beyond the guidelines

Pneumothorax is a serious but common complication in patients with cystic fibrosis (CF). It has adverse prognostic implications as well as associations with subsequent reduction in lung function and significant risk of recurrence. Management dilemmas frequently occur that are beyond current guidelines. We review the evidence and highlight management difficulties in pneumothoraces in CF.

Pneumothorax in cystic fibrosis

Pneumothorax is recognized as a common and life-threatening complication in cystic fibrosis (CF) patients, especially in those who are infected with P. aeruginosa, B. cepacia or Aspergillus, need enteral feeding, are diagnosed as suffering from allergic bronchopulmonary aspergillosis (ABPA), developed massive hemoptysis, and their respiratory function is seriously compromised. Structural impairment and altered airflow dynamics in the lungs of CF patients are considered as the main predisposing factors, but also inhaled medications and non-invasive positive pressure ventilation (NIPPV) could increase the risk of pneumothorax. Clinical presentation could range from dramatic to very mild. Management of spontaneous pneumothorax occurring to patients with CF is essentially similar to that for non-CF patients. Therapeutic options include intercostal tube drainage, video-assisted thoracoscopic surgery (VATS), and medical or surgical pleurodesis. Pneumothorax increases both short- and long-term morbidity and mortality in CF patients and causes significant deterioration of their quality of life.

The combined effect of multidetector-row computed tomographic tube voltage, tube current, and image reconstruction algorithm on the detection of pneumothorax after intervention

OBJECTIVES

The objective of the study was to determine the lowest multidetector-row computed tomographic radiation dose parameters for the detection of pneumothorax after thoracic intervention.

MATERIALS AND METHODS

An anthropomorphic chest phantom containing pneumothoraces was imaged with different tube voltages (80, 100, and 120 kV[p]) and tube currents (10, 20, 40, 75, and 110 mAs). The images were reconstructed with both filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Two blinded radiologists scored images independently for the presence or absence of pneumothorax. Effective dose, image noise, contrast-to-noise ratio, and signal-to-noise ratio were recorded.

RESULTS

At radiation dose below 0.48 mSv, sensitivity for the detection of pneumothorax decreased in both reconstruction algorithms (80% for FBP vs 83% for IR; P > 0.05). Interobserver agreement was good (k = 0.78). The IR data sets showed lower image noise as well as higher signal-to-noise ratio and contrast-to-noise ratio when compared with FBP on all acquisition parameters (P < 0.0001).

CONCLUSIONS

Very low computed tomographic dose parameters may be suitable for confident detection of small pneumothoraces after intervention.

Pneumothorax

Pneumothorax-either spontaneous or iatrogenic-is commonly encountered in pulmonary medicine. While secondary pneumothorax is caused by an underlying pulmonary disease, the spontaneous type occurs in healthy individuals without obvious cause. The British Thoracic Society (BTS, 2010) and the American College of Chest Physicians (ACCP, 2001) published the guidelines for pneumothorax management. This review compares the diagnostic and management recommendations between the two societies. Patients diagnosed with primary spontaneous pneumothorax (PSP) may be observed without intervention if the pneumothorax is small and there are no symptoms. Oxygen therapy is only discussed in the BTS guidelines. If intervention is needed, BTS recommends a simple aspiration in all spontaneous and some secondary pneumothorax cases, whereas ACCP suggests a chest tube insertion rather than a simple aspiration. BTS and ACCP both recommend surgery for patients with a recurrent pneumothorax and persistent air leak. For patients who decline surgery or are poor surgical candidates, pleurodesis is an alternative recommended by both BTS and ACCP guidelines. Treatment strategies of iatrogenic pneumothorax are very similar to PSP. However, recurrence is not a consideration in iatrogenic pneumothorax.

Iatrogenic pneumothorax related to mechanical ventilation

Pneumothorax is a potentially lethal complication associated with mechanical ventilation. Most of the patients with pneumothorax from mechanical ventilation have underlying lung diseases; pneumothorax is rare in intubated patients with normal lungs. Tension pneumothorax is more common in ventilated patients with prompt recognition and treatment of pneumothorax being important to minimize morbidity and mortality. Underlying lung diseases are associated with ventilator-related pneumothorax with pneumothoraces occurring most commonly during the early phase of mechanical ventilation. The diagnosis of pneumothorax in critical illness is established from the patients’ history, physical examination and radiological investigation, although the appearances of a pneumothorax on a supine radiograph may be different from the classic appearance on an erect radiograph. For this reason, ultrasonography is beneficial for excluding the diagnosis of pneumothorax. Respiration-dependent movement of the visceral pleura and lung surface with respect to the parietal pleura and chest wall can be easily visualized with transthoracic sonography given that the presence of air in the pleural space prevents sonographic visualization of visceral pleura movements. Mechanically ventilated patients with a pneumothorax require tube thoracostomy placement because of the high risk of tension pneumothorax. Small-bore catheters are now preferred in the majority of ventilated patients. Furthermore, if there are clinical signs of a tension pneumothorax, emergency needle decompression followed by tube thoracostomy is widely advocated. Patients with pneumothorax related to mechanical ventilation who have tension pneumothorax, a higher acute physiology and chronic health evaluation II score or PaO₂/FiO₂ < 200 mmHg were found to have higher mortality.

Vanishing Lung Syndrome in a Patient with HIV Infection and Heavy Marijuana Use

Vanishing lung syndrome (VLS) is a rare and distinct clinical syndrome that usually affects young men. VLS leads to severe progressive dyspnea and is characterized by extensive, asymmetric, peripheral, and predominantly upper lobe giant lung bullae. Case reports have suggested an additive role of marijuana use in the development of this disease in young male tobacco smokers. We herein report a case of a 65-year-old Hispanic male previously diagnosed with severe emphysema and acquired immune deficiency syndrome (AIDS), with a history of intravenous heroin use and active marijuana smoking who presents to the emergency department with severe progressive shortness of breath he was found to have multiple large subpleural bullae occupying more than one-third of the hemithorax on chest computerized tomography (CT), characteristic of vanishing lung syndrome. The patient was mechanically ventilated and later developed a pneumothorax requiring chest tube placement and referral for surgical bullectomy. Surgical bullectomy has shown high success rates in alleviating the debilitating symptoms and preventing the life threatening complications of this rare syndrome. This case further emphasizes the importance of recognizing VLS in patients with severe emphysema and heavy marijuana smoking.

Chemical pleurodesis for spontaneous pneumothorax

Pneumothorax is defined as the presence of air in the pleural cavity. Spontaneous pneumothorax, occurring without antecedent traumatic or iatrogenic cause, is sub-divided into primary and secondary. The severity of pneumothorax could be varied from asymptomatic to hemodynamically compromised. Optimal management of this benign disease has been a matter of debate. In addition to evacuating air from the pleural space by simple aspiration or chest tube drainage, the management of spontaneous pneumothorax also focused on ceasing air leakage and preventing recurrences by surgical intervention or chemical pleurodesis. Chemical pleurodesis is a procedure to achieve symphysis between the two layers of pleura by sclerosing agents. In the current practice guidelines, chemical pleurodesis is reserved for patients unable or unwilling to receive surgery. Recent researches have found that chemical pleurodesis is also safe and effective in preventing pneumothorax recurrence in patients with the first episode of spontaneous pneumothorax or after thoracoscopic surgery and treating persistent air leakage after thoracoscopic surgery. In this article we aimed at exploring the role of chemical pleurodesis for spontaneous pneumothorax, including ceasing air leakage and preventing recurrence. The indications, choice of sclerosants, safety, effects, and possible side effects or complications of chemical pleurodesis are also reviewed here.

Pneumothorax in the critically ill patient

Pneumothorax in critically ill patients remains a common problem in the ICU, occurring in 4% to 15% of patients. Pneumothorax should be considered a medical emergency and requires a high index of suspicion, prompt recognition, and intervention. The diagnosis of pneumothorax in the critically ill patient can be made by physical examination findings or radiographic studies including chest radiographs, ultrasonography, or CT scanning. Ultrasonography is emerging as the diagnostic procedure of choice for the diagnosis and management guidance and management of pneumothoraces, if expertise is available. Pneumothoraces in unstable, critically ill patients or in those on mechanical ventilation should be managed with tube thoracostomy. If there is suspicion for tension pneumothorax, immediate decompression and drainage should be performed. With widespread use of CT scanning, there have been more occult pneumothoraces diagnosed, and the most recent literature suggests that drainage is preferred. In patients with a persistent air leak or failure of the lung to expand, current guidelines suggest that an early thoracic surgical consultation be requested within 3 to 5 days.

Intensive care management of the patient with cystic fibrosis

Cystic fibrosis was previously thought to be a disease of childhood. With a better understanding of this condition along with improvements in therapy, patients with cystic fibrosis are now living well into adulthood. The aim of this article is to familiarize the intensive care unit physician with cystic fibrosis care, to discuss complications associated with cystic fibrosis specifically related to the intensive care unit, and to detail the current recommendations for the clinical management of the patient with cystic fibrosis. With advancing disease, the most severely affected organs are the lungs. Obstruction, infection, and inflammation contribute to the decline of pulmonary function, ultimately leading to death. Some patients may be eligible for lung transplantation, but choosing wisely will affect posttransplant survival. Because other organs are affected by the genetic defect and associated treatments, serious complications related to the liver, pancreas, intestines, and kidneys must be considered by the intensivist faced with a patient with cystic fibrosis. As practitioners, the fact that not all patients will survive and help our patients and families gracefully through the end-of-life process should be accepted.

Late-Onset Occult Pneumothorax After Lung Volume-Reduction Surgery

BACKGROUND

Lung volume-reduction surgery has proved to be a reliable palliative surgical treatment for patients with severe emphysema. Nonetheless, late complications can arise after lung volume-reduction surgery although this matter has been poorly investigated by previous studies.

METHODS

We report a series of 6 patients undergoing unilateral lung volume-reduction surgery at our institution between October 1995 and December 2004, who were readmitted several months after discharge because of the occurrence of occult pneumothorax mimicking acute respiratory failure.

RESULTS

Occult pneumothorax occurred in 3.3% of the 182 patients treated with lung volume-reduction surgery at our institution. Patients were readmitted after a mean of 94 days (range, 20 to 700 days) from the discharge. Chest roentgenography was unable to detect the occurrence of pneumothorax, which was instead revealed by means of a computed tomographic scan in all patients. The interval between admission and correct diagnosis averaged 22.4 hours. The number of air collections ranged between two and four. Treatment entailed solely blind chest drainage placement in 2 patients and awake video-assisted thoracoscopic surgery in the others, including placement of chest tube under direct vision in 1 patient, repair of lung tears by means of cyanoacrylate glue in 2 and bovine pericardium patch plus cyanoacrylate glue apposition in 1 patient.

CONCLUSIONS

In conclusion, we believe that occult pneumothorax should be kept in mind as one of the possible late complications of lung volume-reduction surgery and should be suspected whenever sudden worsening of dyspnea is noticed even in the presence of an uneventful chest roentgenogram. Awake video-assisted thoracoscopic surgery management can represent an effective option in these instances.

Giant bulla mimicking pneumothorax

It is usually thought by emergency physicians that the diagnosis of a pneumothorax is straightforward and easy to make and to treat, but the diagnosis may sometimes pose a challenge. The present report describes a case of a giant pulmonary bulla in a 40-year-old man that progressed to occupy almost the entire left hemithorax and also subsequently ruptured to produce a large left pneumothorax. The giant bulla was diagnosed only as a pneumothorax, and initially managed with a chest tube only. The differentiation between pneumothorax and a giant bulla can be very difficult, and often leads to inaccurate diagnosis and management. This case report demonstrates the clinical presentation of giant bulla and its complications such as pneumothorax and also highlights the difficulty in making this diagnosis and appropriately treating it. In this article, we emphasized how to differentiate between giant bulla and pneumothorax utilizing history, physical examination, and radiological studies including computed tomography (CT) scan.

Difficulties in the diagnosis of rare immunological diseases manifesting with cystic lung disease and spontaneous pneumothorax: case reports

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease of an unknown cause affecting women of reproductive age and characterised by smooth muscle proliferation along lung lymphatic channels. Pneumothorax develops in up to 80% of patients with LAM and may be the presenting manifestation of the disease. Pneumothorax also precedes or complicates the clinical course of 25% of patients with Langerhans'-cell histiocytosis (LCH, histiocytosis X) pathologically characterised by involved tissue infiltration with large numbers of unusual Langerhans' cells, often organised as granulomas. A 41-year-old female patient was treated twice by simple tube drainage due to left pneumothorax in 1996. She was then diagnosed with chronic obstructive lung disease demonstrating with dyspnea, cough and wheeze. Abnormalities found in the high-resolution computed tomography (HRCT) scanning were characteristic of LAM with thin-walled parenchymal cysts distributed homogeneously in both lungs and with thickening of interlobular septa. A 38-year-old man was hospitalised due to chronic lung failure in the course of LCH characterised by small, poorly limited nodular lesions and thin-walled cysts revealed in HRCT scans. For two years of observation, he has suffered five episodes of right pneumothorax. When diagnosing pneumothorax in the middle-age patients, the possible cause of the disease is LAM or LCH. The use of HRCT scanning may enable good determination of the nature and distribution of parenchymal abnormalities found in the diseases.

Pneumothorax in cystic fibrosis

Spontaneous pneumothorax is a common complication in patients with cystic fibrosis (CF). It is thought to occur more frequently in patients with more advanced disease. Recommendations on the management of pneumothorax in CF are based on retrospective analyses and reports from CF centers. The following is a review of what has been published regarding the incidence and management of pneumothorax in this population, with some comment on the pathogenesis of the complication.

Usefulness of the double-wall sign in detecting pneumothorax in patients with giant bullous emphysema

OBJECTIVE

We describe a new sign improving detection of pneumothorax in patients with giant bullous emphysema: air surrounding both sides of the bulla wall (the intrathoracic equivalent of the double-wall sign of pneumoperitoneum). We report the radiographic and CT appearances of the double-wall sign in seven patients with giant bullous emphysema, four of whom had pneumothorax.

CONCLUSION

Recognizing the double-wall sign of pneumothorax should aid in the triage of patients with giant bullous emphysema.