Validity of CT classification on management of occult pneumothorax: a prospective study

Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST)

BACKGROUND

Thoracic ultrasound (EFAST) has shown promise in inferring the presence of post-traumatic pneumothoraces (PTXs) and may have a particular value in identifying occult pneumothoraces (OPTXs) missed by the AP supine chest radiograph (CXR). However, the diagnostic utility of hand-held US has not been previously evaluated in this role.

METHODS

Thoracic US examinations were performed during the initial resuscitation of injured patients at a provincial trauma referral center. A high frequency linear transducer and a 2.4 kg US attached to a video-recorder were used. Real-time EFAST examinations for PTXs were blindly compared with the subsequent results of CXRs, a composite standard (CXR, chest and abdominal CT scans, clinical course, and invasive interventions), and a CT gold standard (CT only). Charts were reviewed for in-hospital outcomes and follow-up.

RESULTS

There were 225 eligible patients (207 blunt, 18 penetrating); 17 were excluded from the US examination because of battery failure or a lost probe. Sixty-five (65) PTXs were detected in 52 patients (22% of patients), 41 (63%) being occult to CXR in 33 patients (14.2% whole population, 24.6% of those with a CT). The US and CXR agreed in 186 (89.4%) of patients, EFAST was better in 16 (7.7%), and CXR better in 6 (2.9%). Compared with the composite standard, the sensitivity of EFAST was 58.9% with a likelihood ratio of a positive test (LR+) of 69.7 and a specificity of 99.1%. Comparing EFAST directly to CXR, by looking at each of 266 lung fields with the benefit of the CT gold standard, the EFAST showed higher sensitivity over CXR (48.8% versus 20.9%). Both exams had a very high specificity (99.6% and 98.7%), and very predictive LR+ (46.7 and 36.3).

CONCLUSION

EFAST has comparable specificity to CXR but is more sensitive for the detection of OPTXs after trauma. Positive EFAST findings should be addressed either clinically or with CT depending on hemodynamic stability. CT should be used if detection of all PTXs is desired.

What size chest tube? What drainage system is ideal? And other chest tube management questions

Chest tubes and their accompanying pleural drainage units continue to present challenging questions regarding their optimal use. Appropriate chest tube size selection to accommodate the clinical situation is key, especially in the setting of large pleural air leaks lest a tension pneumothorax ensue. Connection of an appropriate pleural drainage unit to the chest tube is equally important to obviate impeding airflow after successful evacuation by the chest tube. Large-bore chest tubes are generally required for patients with pneumothoraces, regardless of etiology, if the patient is mechanically ventilated, or for patients requiring drainage of viscous pleural liquids such as blood. Smaller bore tubes may be adequate in patients with limited production of pleural air or of free-flowing pleural liquid. Chest tubes may be removed successfully at either end expiration or end inspiration, and potentially as soon as </=200 mL/fluid output per day is achieved. Additional prospective studies are needed to provide evidence-based answers to the many questions remaining regarding chest tube placement, ongoing management, and removal.

Pulmonary trauma emergency department evaluation and management

Pulmonary trauma is a significant cause of morbidity and mortality in the United States. It is imperative for the emergency physician to identify promptly patients who require immediate therapy. In patients who have limited injuries, literature shows that often conservative management provides improved outcome. As the exposure to automobiles and firearms continues to increase in the setting of improved prehospital management, the emergency physician will encounter an increasing amount of pulmonary trauma. This rise in respiratory injuries will require a more aggressive approach of patients with minimal morbidity and mortality. A systematic approach to respiratory injuries is crucial to improving patient outcomes.

Management of pneumothorax and barotrauma: current concepts

Pneumothorax can be spontaneous, traumatic or iatrogenic. Pneumothorax ex vacuo, sports-related pneumothorax and barotrauma unrelated to mechanical ventilation are interesting and newer entities. Management consists of getting rid of the air and prevention of recurrence of pneumothorax.

Prevalence and importance of pneumothoraces visualized on abdominal computed tomographic scan in children with blunt trauma

BACKGROUND

Chest radiographs are routinely obtained for the identification of pneumothoraces in trauma patients. Computed tomographic (CT) scanning has a higher sensitivity for the detection of pneumothoraces, but the prevalence and importance of pneumothoraces detectable by CT scan but not by chest radiography in children sustaining blunt trauma is unclear.

METHODS

We conducted a prospective observational cohort study of children less than 16 years old with blunt trauma undergoing both abdominal CT scan and chest radiography in the emergency department of a Level I trauma center over a 28-month period. All abdominal CT scans were interpreted by a single faculty radiologist. The chest radiographs of all patients with pneumothoraces detected on CT scan as well as a random sample of chest radiographs from pediatric blunt trauma patients without pneumothoraces on abdominal CT scan (in a ratio of four normals per pneumothorax) were reviewed by a second faculty radiologist. Both radiologists were masked to all clinical data as well as to the objective of the study.

RESULTS

Five hundred thirty-eight children underwent both abdominal CT scan and chest radiography in the emergency department. Twenty patients (3.7%; 95% confidence interval [CI], 2.3-5.7%) were found to have pneumothoraces on CT scan. Of these 20 patients, 9 (45%; 95% CI, 23-68%) had pneumothoraces identified on initial chest radiography and 11 patients did not ("unsuspected pneumothoraces"). Twelve pneumothoraces were identified in these 11 patients; 6 were graded as minuscule and 6 as anterior according to a previously established scale. One patient with an unsuspected pneumothorax underwent tube thoracostomy. None of the 10 patients (0%; 95% CI, 0-26%) with unsuspected pneumothoraces who were managed without thoracostomy (including two patients who underwent positive pressure ventilation) had complications from their pneumothoraces.

CONCLUSION

Less than half of pediatric blunt trauma patients with pneumothoraces visualized on abdominal CT scan had these pneumothoraces identified on initial chest radiograph. Patients with pneumothoraces identified solely on abdominal CT scan, however, uncommonly require tube thoracostomy.

Detection of occult pneumothoraces on abdominal computed tomographic scans in trauma patients

BACKGROUND

An unrecognized, or occult, injury is particularly dangerous in trauma patients, who often have multiple life-threatening injuries. We sought to determine the frequency and quantify the utility of the abdominal computed tomographic (CT) scan in detecting occult pneumothoraces.

METHODS

Charts of all trauma patients diagnosed with a pneumothorax over a 7-year period were retrospectively reviewed for findings on admission chest radiograph, abdominal CT scan, and other demographic data.

RESULTS

A total of 312 charts were reviewed, with 230 patients identified as having a pneumothorax at admission. Of the 230 patients, 126 (54.8%) had an occult pneumothorax identified on abdominal CT scan. In these patients, the mean Trauma Score was 14.1 +/- 2.9 and the mean Injury Severity Score was 24.1 +/- 11.2. In the group of occult pneumothoraces, 84 (66.7%) underwent chest tube placement.

CONCLUSIONS

Abdominal CT scanning provided important information about thoracic trauma often missed on initial evaluation in the trauma bay. This information frequently affected the patient's clinical management.

Pleural complications in the intensive care unit

In summary pleural complications in the ICU are common. Pneumothorax in a mechanically ventilated patient is a medical emergency that requires prompt diagnosis and therapy. Correct diagnosis and therapy of pleural effusions will assist in improving pulmonary physiology and outcome in the ICU patient.