The OPTICC trial: a multi-institutional study of occult pneumothoraces in critical care

Surgical management of chest injuries in patients with multiple and/or severe trauma- a systematic review and clinical practice guideline update

PURPOSE

Our aim was to update evidence-based and consensus-based recommendations for the surgical and interventional management of blunt or penetrating injuries to the chest in patients with multiple and/or severe injuries on the basis of current evidence. This guideline topic is part of the 2022 update of the German Guideline on the Treatment of Patients with Multiple and/or Severe Injuries.

METHODS

MEDLINE and Embase were systematically searched to May and June 2021 respectively for the update and new questions. Further literature reports were obtained from clinical experts. Randomised controlled trials, prospective cohort studies, cross-sectional studies and comparative registry studies were included if they compared interventions for the surgical management of injuries to the chest in patients with multiple and/or severe injuries. We considered patient-relevant clinical outcomes such as mortality, length of stay, and diagnostic test accuracy. Risk of bias was assessed using NICE 2012 checklists. The evidence was synthesised narratively, and expert consensus was used to develop recommendations and determine their strength.

RESULTS

One study was identified. This study compared wedge resection, lobectomy and pneumonectomy in the management of patients with severe chest trauma that required some form of lung resection. Based on the updated evidence and expert consensus, one recommendation was modified and two additional good practice points were developed. All achieved strong consensus. The recommendation on the amount of blood loss that is used as an indication for surgical intervention in patients with chest injuries was modified to reflect new findings in trauma care and patient stabilisation. The new good clinical practice points (GPPs) on the use of video-assisted thoracoscopic surgery (VATS) in patients with initial circulatory stability are also in line with current practice in patient care.

CONCLUSION

As has been shown in recent decades, the treatment of chest trauma has become less and less invasive for the patient as diagnostic and technical possibilities have expanded. Examples include interventional stenting of aortic injuries, video-assisted thoracoscopy and parenchyma-sparing treatment of lung injuries. These less invasive treatment concepts reduce morbidity and mortality in the primary surgical phase following a chest trauma.

Observational management of penetrating occult pneumothoraces: Outcomes and risk factors for interval tube thoracostomy placement

BACKGROUND

Guidelines for penetrating occult pneumothoraces (OPTXs) are based on blunt injury. Further understanding of penetrating OPTX pathophysiology is needed. In observational management of penetrating OPTX, we hypothesized that specific clinical and radiographic features may be associated with interval tube thoracostomy (TT) placement. Our aims were to (1) describe OPTX occurrence in penetrating chest injury, (2) determine the rate of interval TT placement in observational management and clinical outcomes compared with immediate TT placement, and (3) describe risk factors associated with failure of observational management.

METHODS

Penetrating OPTX patients presenting to our level 1 trauma center from 2004 to 2019 were reviewed. Occult pneumothorax was defined as a pneumothorax on chest computed tomography but not on chest radiograph. Patient groups included immediate TT placement versus observation. Clinical outcomes compared were TT duration and complications, need for additional thoracic procedures, length of stay (LOS), and disposition. Clinical and radiographic factors associated with interval TT placement were determined by multivariable regression.

RESULTS

Of 629 penetrating pneumothorax patients, 103 (16%) presented with OPTX. Thirty-eight patients underwent immediate TT placement, and 65 were observed. Twelve observed patients (18%) needed interval TT placement. Regardless of initial management strategy, TT placement was associated with longer LOS and more chest radiographs. Chest injury complications and outcomes were similar. Factors associated with increased odds of interval TT placement included Chest Abbreviated Injury Scale score of ≥4 (adjusted odds ratio [aOR], 7.38 [95% confidence interval, 1.43-37.95), positive pressure ventilation (aOR, 7.74 [1.07-56.06]), concurrent hemothorax (aOR, 6.17 [1.08-35.24]), and retained bullet fragment (aOR, 11.62 [1.40-96.62]) (all p < 0.05).

CONCLUSION

The majority of patients with penetrating OPTX can be successfully observed with improved clinical outcomes (LOS, avoidance of TT complications, reduced radiation). Interval TT intervention was not associated with risk for adverse outcomes. In patients undergoing observation, specific clinical factors (chest injury severity, ventilation) and imaging features (hemothorax, retained bullet) are associated with increased odds for interval TT placement, suggesting need for heightened awareness in these patients.

LEVEL OF EVIDENCE

Prognostic, level IV.

Consent models in Canadian critical care randomized controlled trials: a scoping review

PURPOSE

Our primary objective was to describe consent models used in Canadian-led adult and pediatric intensive care unit (ICU/PICU) randomized controlled trials (RCTs). Our secondary objectives were to determine the consent rate of ICU/PICU RCTs that did and did not use an alternate consent model to describe consent procedures.

SOURCE

Using scoping review methodology, we searched MEDLINE, Embase, and CENTRAL databases (from 1998 to June 2019) for trials published in English or French. We included Canadian-led RCTs that reported on the effects of an intervention on ICU/PICU patients or their families. Two independent reviewers assessed eligibility, abstracted data, and achieved consensus.

PRINCIPAL FINDINGS

We identified 48 RCTs of 17,558 patients. Included RCTs had ethics approval to use prior informed consent (43/48; 90%), deferred consent (13/48; 27%), waived consent (5/48; 10%), and verbal consent (1/48; 2%) models. Fifteen RCTs (15/48; 31%) had ethics approval to use more than one consent model. Twice as many trials used alternate consent between 2010 and 2019 (13/19) than between 2000 and 2009 (6/19). The consent rate for RCTs using only prior informed consent ranged from 54 to 91% (ICU) and 43 to 94% (PICU) and from 78 to 100% (ICU) and 74 to 87% (PICU) in trials using an alternate/hybrid consent model.

CONCLUSION

Alternate consent models were used in the minority of Canadian-led ICU/PICU RCTs but have been used more frequently over the last decade. This suggests that Canadian ethics boards and research communities are becoming more accepting of alternate consent models in ICU/PICU trials.

Conservative management of occult pneumothorax in mechanically ventilated patients: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review was to investigate the safety and effectiveness of conservative management versus prophylactic intercostal catheter (ICC) insertion for the management of occult pneumothoraces in mechanically ventilated patients.

METHODS

PubMed, Embase, CINAHL, Web of Science, Cochrane Central, and other trial registries were searched. Eligible studies were critically appraised using standardized instruments. Meta-analysis was performed with mixed-methods logistic regression where appropriate and sensitivity analyses were performed with alternative statistical methods (Stata™ 15 or RevMan 5.3) or summarized in narrative. Randomized controlled trials (RCTs) and cohort studies were analyzed separately.

RESULTS

Twelve studies with a total of 354 participants were included; three RCTs (178 participants) and nine cohort studies (176 participants). The majority of the included studies, particularly the cohort studies, were well conducted. Two of the RCTs were rated as low quality. Statistically significant differences were observed in the RCT analysis: ICC insertion (any reason) (odds ratio, 2.86; 95% confidence interval, 1.26-6.43, 2 RCTs) in favor of prophylactic ICC; ICC complications (odds ratio, 0.12; 95% confidence interval, 0.02-0.62, 2 RCTs) in favor of conservative management. Nonstatistically significant differences were observed for progression of pneumothorax, ICC insertion (progression to simple pneumothorax), and ICC insertion (nonpneumothorax reasons). Results of analyses showed high imprecision (wide confidence limits). Conservative management showed a low rate of tension pneumothorax (2.8%). Complications were higher in the ICC group (19.5% vs. 5.8%).

CONCLUSION

Available evidence suggests that conservative management is safe for the management of occult pneumothoraces in mechanically ventilated patients, especially when undergoing short-term (<4 days) ventilation. We recommend that patients undergoing mechanical ventilation for a procedure alone and patients suspected to be ventilated less than 4 days can be conservatively managed.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level III.

Management of complex pleural disease in the critically ill patient

Disorders of the pleural space are quite common in the critically ill patient. They are generally associated with the underlying illness. It is sometimes difficult to assess for pleural space disorders in the ICU given the instability of some patients. Although the portable chest X-ray remains the primary modality of diagnosis for pleural disorders in the ICU. It can be nonspecific and may miss subtle findings. Ultrasound has become a useful tool to the bedside clinician to aid in diagnosis and management of pleural disease. The majority of pleural space disorders resolve as the patient’s illness improves. There remain a few pleural processes that need specific therapies. While uncomplicated parapneumonic effusions do not have their own treatments. Those that progress to become a complex infected pleural space can have its individual complexity in therapy. Chest tube drainage remains the cornerstone in therapy. The use of intrapleural fibrinolytics has decreased the need for surgical referral. A large hemothorax or pneumothorax in patients admitted to the ICU represent medical emergencies and require emergent action. In this review we focus on the management of commonly encountered complex pleural space disorders in critically ill patients such as complicated pleural space infections, hemothoraces and pneumothoraces.

OPTICC: A multicentre trial of Occult Pneumothoraces subjected to mechanical ventilation: The final report

INTRODUCTION

Patients with occult pneumothorax (OPTX) requiring positive-pressure ventilation (PPV) face uncertain risks of tension pneumothorax or chest drainage complications.

METHODS

Adults with traumatic OPTXs requiring PPV were randomized to drainage/observation, with the primary outcome of composite "respiratory distress" (RD)).

RESULTS

Seventy-five (75) patients were randomized to observation, 67 to drainage. RD occurred in 38% observed and 25% drained (p = 0.14; Power = 0.38), with no mortality differences. One-quarter of observed patients failed, reaching 40% when ventilated >5 days. Twenty-three percent randomized to drainage had complications or ineffectual drains.

CONCLUSION

RD was not significantly different with observation. Thus, OPTXs may be cautiously observed in stable patients undergoing short-term PPV when prompt "rescue drainage" is immediately available. As 40% of patients undergoing prolonged (≥5 days) ventilation (PPPV) require drainage, we suggest consideration of chest drainage performed with expert guidance to reduce risk of chest tube complications.

LEVEL OF EVIDENCE

Therapeutic study, level II.

Effectiveness and safety of conservative management of occult pneumothorax in mechanically ventilated patients: a systematic review protocol

OBJECTIVE

This systematic review aims to synthesize the available evidence investigating the effectiveness and safety of conservative management of occult pneumothorax in mechanically ventilated patients.

INTRODUCTION

Occult pneumothorax is air within the pleural cavity that is diagnosed on a CT scan but was not suspected on the basis of preceding clinical examination or supine chest x-ray. Currently, there is no consensus on how to manage occult pneumothoraces, especially in patients requiring mechanical ventilation. It is common practice to place a prophylactic intercostal catheter to stop the potential development of a tension pneumothorax; however, there is a 20% risk of major complications from the intercostal catheter insertion. Recent evidence suggests that occult pneumothorax in mechanically ventilated patients can be managed conservatively, rather than using a prophylactic intercostal catheter as first-line management.

INCLUSION CRITERIA

This review will include studies investigating stable patients of all ages who were diagnosed with traumatic occult pneumothorax via CT scan, received mechanical ventilation, and underwent either conservative management or intercostal catheter insertion.

METHODS

Eligible studies will include randomized and non-randomized controlled trials, and prospective and retrospective cohort studies. PubMed, Embase, CINAHL, Web of Science, and Cochrane Central Register of Controlled Trials will be searched. International Clinical Trials Registry, Australian New Zealand Clinical Trials Registry, and ClinicalTrials.gov will be searched for unpublished studies. All included studies will be critically appraised using standardized JBI tools, with no exclusions based on methodological quality. Studies will, where possible, be pooled in statistical meta-analysis, with impact of methodological quality to be explored through sensitivity analysis.

Observing pneumothoraces: The 35-millimeter rule is safe for both blunt and penetrating chest trauma

BACKGROUND

As more pneumothoraxes (PTX) are being identified on chest computed tomography (CT), the empiric trigger for tube thoracostomy (TT) versus observation remains unclear. We hypothesized that PTX measuring 35 mm or less on chest CT can be safely observed in both penetrating and blunt trauma mechanisms.

METHODS

A retrospective review was conducted of all patients diagnosed with PTX by chest CT between January 2011 and December 2016. Patients were excluded if they had an associated hemothorax, an immediate TT (TT placed before the initial chest CT), or if they were on mechanical ventilation. Size of PTX was quantified by measuring the radial distance between the parietal and visceral pleura/mediastinum in a line perpendicular to the chest wall on axial imaging of the largest air pocket. Based on previous work, a cutoff of 35 mm on the initial CT was used to dichotomize the groups. Failure of observation was defined as the need for a delayed TT during the first week. A univariate analysis was performed to identify predictors of failure in both groups, and multivariate analysis was constructed to assess the independent impact of PTX measurement on the failure of observation while controlling for demographics and chest injuries.

RESULTS

Of the 1,767 chest trauma patients screened, 832 (47%) had PTX, and of those meeting inclusion criteria, 257 (89.0%) were successfully observed until discharge. Of those successfully observed, 247 (96%) patients had a measurement of 35 mm or less. The positive predictive value for 35 mm as a cutoff was 90.8% to predict successful observation. In the univariant analyses, rib fractures (p = 0.048), Glasgow Coma Scale (p = 0.012), and size of the PTX (≤35 mm or >35 mm) (P < 0.0001) were associated with failed observation. In multivariate analysis, PTX measuring 35 mm or less was an independent predictor of successful observation (odds ratio, 0.142; 95% confidence interval, 0.047-0.428)] for the combined blunt and penetrating trauma patients.

CONCLUSION

A 35-mm cutoff is safe as a general guide with only 9% of stable patients failing initial observation regardless of mechanism.

LEVEL OF EVIDENCE

Therapeutic, level III.

X-ray indices of chest drain malposition after insertion for drainage of pneumothorax in mechanically ventilated critically ill patients

BACKGROUND

Chest drain (CD) migration in the pleural cavity may result in inadequate drainage of pneumothorax. The aim of this study was to assess several parameters that might help in diagnosing CD migration on chest X-ray (CXR).

METHODS

Patients with a CD inserted from the safe triangle with a subsequent supine CXR and CT scan performed less than 24 hours apart were assessed for CD foreshortening, angle of inclination of the CD, and CD tortuosity. CD foreshortening was expressed as a ratio between CD length measured in coronal plane only and CD length inside the pleural cavity measured on CT. The angle of inclination of the CD was measured as the angle between the horizontal line and CD at the pleural space entry on CXR. CD tortuosity was calculated as a ratio between the distance from CD pleural space entry to the tip of the CD and the length of CD from the pleural space entry to its tip on CXR.

RESULTS

Altogether 28 patients were included in the study. The median time between the CXR and CT examinations was 5.4 hours (IQR, 3.8-6.9 hours). CD foreshortening was the best clue of a misplaced CD with AUC of 0.93, 100% sensitivity and 88% specificity for a cut-off value of 82%. The angle of CD inclination was greater in patients with misplaced CD with AUC of 0.83, 75% sensitivity and 92% specificity for a cut-off of 50 degrees. The performance of CD tortuosity was poor.

CONCLUSIONS

Greater foreshortening of the CD and a steep angle of inclination of the CD above the horizontal at chest entry should raise suspicion of CD migration and mandate further investigation by chest ultrasound to rule out residual pneumothorax occult on CXR.

Limiting thoracic CT: a rule for use during initial pediatric trauma evaluation

BACKGROUND

Despite increases in imaging guidelines for other body-regions during initial trauma assessment and the demonstrated utility of chest radiographs (CXR), guidelines for use of thoracic computed-tomography (TCT) are lacking. We hypothesized that TCT utilization had not decreased relative to other protocolized CTs, and mechanism and CXR could together predict significant injury independent of TCT.

METHODS

We performed a retrospective review of blunt trauma patients ≤18 y.o. (2007-2015) at two level-1 trauma centers who received chest imaging. Baseline characteristics and incidences of body region-specific CT were compared. Injury mechanism, intrathoracic pathology, and interventions among other data were examined (significance: p<0.05).

RESULTS

Although other body-region CT incidence decreased (p<0.05), TCT incidence did not change (p=0.65). Of the 2951 patients, 567 had both CXR and TCT, 933 received TCT-only, and 1451 had CXR-only. TCT altered management in 17 patients: 2 operations, 1 stent-placement, 1 medical management, 9 thoracostomy tube placements, and 4 negative diagnostic workups. All clinically significant changes were predicted by vehicle-related mechanism and abnormal CXR findings.

CONCLUSIONS

TCT utilization has not decreased over time. All meaningful interventions were predicted by CXR and mechanism of injury. We propose a rule, for prospective validation, reserving TCT for patients with abnormal CXR findings and severe vehicle-related trauma.

LEVEL OF EVIDENCE

Diagnostic study, Level III.

Care of Traumatic Conditions in an Observation Unit

Patients presenting to the emergency department with certain traumatic conditions can be managed in observation units. The evidence base supporting the use of observation units to manage injured patients is smaller than the evidence base supporting the management of medical conditions in observation units. The conditions that are eligible for management in an observation unit are not limited to those described in this article, and investigators should continue to identify types of conditions that may benefit from this type of health care delivery.

A case of iatrogenic pneumothorax in which chest tube placement could be avoided by intraoperative evaluation with transthoracic ultrasonography

We report a case of iatrogenic pneumothorax in which chest tube placement was avoided by continuous intraoperative evaluation with transthoracic ultrasonography. A 53-year-old man had undergone a subsegmentectomy. While attempting to place a central venous catheter in the right internal jugular vein after the induction of anesthesia, we identified gas absorption during the puncture and suspected a pneumothorax. Chest X-ray revealed an ~5-mm collapse of the right lung apex. Tension pneumothorax was a concern during surgery because of the long-term positive pressure ventilation, but we decided to start the operation without preventative chest tube placement. During the operation, we regularly observed the midclavicular line of the second intercostal space using ultrasound. The operation was completed uneventfully. In this case, we effectively utilized ultrasound and avoided preventive chest tube placement and the associated complications. Transthoracic ultrasonography could be performed easily and continuously during surgery and was effective for evaluating the progression of an intraoperative pneumothorax.

Chest trauma: First 48hours management

Chest trauma remains an issue for health services for both severe and apparently mild trauma management. Severe chest trauma is associated with high mortality and is considered liable for 25% of mortality in multiple traumas. Moreover, mild trauma is also associated with significant morbidity especially in patients with preexisting conditions. Thus, whatever the severity, a fast-acting strategy must be organized. At this time, there are no guidelines available from scientific societies. These expert recommendations aim to establish guidelines for chest trauma management in both prehospital an in hospital settings, for the first 48hours. The "Société française d'anesthésie réanimation" and the "Société française de médecine d'urgence" worked together on the 7 following questions: (1) criteria defining severity and for appropriate hospital referral; (2) diagnosis strategy in both pre- and in-hospital settings; (3) indications and guidelines for ventilatory support; (4) management of analgesia; (5) indications and guidelines for chest tube placement; (6) surgical and endovascular repair indications in blunt chest trauma; (7) definition, medical and surgical specificity of penetrating chest trauma. For each question, prespecified "crucial" (and sometimes also "important") outcomes were identified by the panel of experts because it mattered for patients. We rated evidence across studies for these specific clinical outcomes. After a systematic Grade^® approach, we defined 60 recommendations. Each recommendation has been evaluated by all the experts according to the DELPHI method.

Case Report: Perioperative management of a pregnant poly trauma patient for spine fixation surgery

Trauma is estimated to complicate approximately one in twelve pregnancies, and is currently a leading non-obstetric cause of maternal death. Pregnant trauma patients requiring non-obstetric surgery pose a number of challenges for anesthesiologists. Here we present the successful perioperative management of a pregnant trauma patient with multiple injuries including occult pneumothorax who underwent T9 to L1 fusion in prone position, and address the pertinent perioperative anesthetic considerations and management.

Prevalence of large and occult pneumothoraces in patients with severe blunt trauma upon hospital admission: experience of 526 cases in a French level 1 trauma center

BACKGROUND

Occult pneumothoraces (PTXs), which are not visible on chest x-ray, may progress to tension PTX. The aim of study was to establish the prevalence of large occult PTXs upon admission of patients with severe blunt trauma, according to prehospital mechanical ventilation.

METHODS

Patients with severe trauma consecutively admitted to our institution for 5 years were retrospectively analyzed. All patients with blunt thoracic trauma who had undergone computed tomographic (CT) within the first hour of hospitalization were included. Mechanical ventilation was considered as early if it was introduced in the prehospital period or on arrival at the hospital. Occult PTXs were defined as PTXs not visible on chest x-ray. All PTXs were measured on CT scan (largest thickness and vertical dimension). Large occult PTXs were defined by a largest thickness of 30 mm or more.

RESULTS

Of the 526 patients studied, 395 (75%) were male, mean age was 37.9 years, mean Injury Severity Score was 22.2, and 247 (47%) received early mechanical ventilation. Of 429 diagnosed PTXs, 296 (69%) were occult. The proportion of occult PTXs classified as large was 11% (95% confidence interval, 8%-15%). The overall prevalence of large occult PTXs was 6% (95% confidence interval, 4%-8%). Both CT measurements and proportion of large occult PTXs were found statistically comparable in patients with or without mechanical ventilation.

CONCLUSIONS

Six percent of studied patients with severe trauma had a large and occult PTX as soon as admission despite a normal chest x-ray result. The observed sizes and rates of occult PTX were comparable regardless of the initiation of early mechanical ventilation.

[Results of conservative treatment in patients with occult pneumothorax]

INTRODUCTION

An occult pneumothorax is found in 2-15% trauma patients. Observation (without tube thoracostomy) in these patients presents still some controversies in the clinical practice. The objective of the study is to evaluate the efficacy and the adverse effects when observation is performed.

METHODS

A retrospective observational study was undertaken in our center (university hospital level II). Data was obtained from a database with prospective registration. A total of 1087 trauma patients admitted in the intensive care unit from 2006 to 2013 were included.

RESULTS

In this period, 126 patients with occult pneumothorax were identified, 73 patients (58%) underwent immediate tube thoracostomy and 53 patients (42%) were observed. Nine patients (12%) failed observation and required tube thoracostomy for pneumothorax progression or hemothorax. No patient developed a tension pneumothorax or experienced another adverse event related to the absence of tube thoracostomy. Of the observed patients 16 were under positive pressure ventilation, in this group 3 patients (19%) failed observation. There were no differences in mortality, hospital length of stay or intensive care length of stay between the observed and non-observed group.

CONCLUSION

Observation is a safe treatment in occult pneumothorax, even in pressure positive ventilated patients.

Surgical management for the first 48 h following blunt chest trauma: state of the art (excluding vascular injuries)

This review aims to answer the most common questions in routine surgical practice during the first 48 h of blunt chest trauma (BCT) management. Two authors identified relevant manuscripts published since January 1994 to January 2014. Using preferred reporting items for systematic reviews and meta-analyses statement, they focused on the surgical management of BCT, excluded both child and vascular injuries and selected 80 studies. Tension pneumothorax should be promptly diagnosed and treated by needle decompression closely followed with chest tube insertion (Grade D). All traumatic pneumothoraces are considered for chest tube insertion. However, observation is possible for selected patients with small unilateral pneumothoraces without respiratory disease or need for positive pressure ventilation (Grade C). Symptomatic traumatic haemothoraces or haemothoraces >500 ml should be treated by chest tube insertion (Grade D). Occult pneumothoraces and occult haemothoraces are managed by observation with daily chest X-rays (Grades B and C). Periprocedural antibiotics are used to prevent chest-tube-related infectious complications (Grade B). No sign of life at the initial assessment and cardiopulmonary resuscitation duration >10 min are considered as contraindications of Emergency Department Thoracotomy (Grade C). Damage Control Thoracotomy is performed for either massive air leakage or refractive shock or ongoing bleeding enhanced by chest tube output >1500 ml initially or >200 ml/h for 3 h (Grade D). In the case of haemodynamically stable patients, early video-assisted thoracic surgery is performed for retained haemothoraces (Grade B). Fixation of flail chest can be considered if mechanical ventilation for 48 h is probably required (Grade B). Fixation of sternal fractures is performed for displaced fractures with overlap or comminution, intractable pain or respiratory insufficiency (Grade D). Lung herniation, traumatic diaphragmatic rupture and pericardial rupture are life-threatening situations requiring prompt diagnosis and surgical advice. (Grades C and D). Tracheobronchial repair is mandatory in cases of tracheal tear >2 cm, oesophageal prolapse, mediastinitis or massive air leakage (Grade C). These evidence-based surgical indications for BCT management should support protocols for chest trauma management.

Pneumothorax: observation

Pneumothorax based on the cause, it can be divided into two large categories; primary and secondary. The staging of pneumothorax plays a crucial role for treatment. Currently both thoracic surgeons and pulmonary physicians can handle efficiently treatment. Pulmonary physicians with the minimally medical thoracoscopy while thoracic surgeons with a more extensive intervention. Experience defines the outcome in most situations and not the method. In our current work we will present data regarding the observation of pneumothorax from a panel of experts.

Semi-quantification of pneumothorax volume by lung ultrasound

BACKGROUND

Lung ultrasound (LUS) may accurately diagnose pneumothorax. However, there is uncertainty about its usefulness in the quantification of pneumothorax size. To determine the ability of LUS in the semi-quantification of pneumothorax volume, we compared the projection of the lung point (LP) with the pneumothorax volume measured by computerized tomography (CT) and the interpleural distance on chest radiography (CXR).

METHODS

We performed LUS in patients with pneumothorax and all the LP located on the chest wall were compared to CXR and CT studies. The primary outcome of the study was the ability of LP to grade pneumothorax volumes measured by CT. The secondary outcome was the accuracy of LP to predict small and large pneumothorax according to the societal guidelines based on CXR reading.

RESULTS

A total of 124 patients with pneumothorax were enrolled (76 spontaneous, 20 traumatic and 28 post-procedural). Ninety-four CXR and 58 CT were available for the analysis. An LP posterior to the mid axillary line corresponded to three different CXR criteria for large pneumothorax with sensitivity from 81.4 to 88.2 % and specificity from 64.7 to 72.6 %. The mid axillary line also represented the limit for predicting greater than 15 % of lung collapse when volume is measured at CT, with sensitivity 83.3 % and specificity 82.4 %.

CONCLUSIONS

LUS-targeted assessment of LP was a useful predictor of pneumothorax volume in this research study setting. LUS reliably classified pneumothorax size when compared to criteria based on CXR reading, particularly the small sized pneumothorax. However, LUS greatly outperformed conventional CXR reading for a graded quantification of the percentage of lung collapse.

Tension Pneumothorax During Surgery for Thoracic Spine Stabilization in Prone Position: A Case Report and Review of Literature

The intraoperative progression of a simple or occult pneumothorax into a tension pneumothorax can be a devastating clinical scenario. Routine use of prophylactic thoracostomy prior to anesthesia and initiation of controlled ventilation in patients with simple or occult pneumothorax remains controversial. We report the case of a 75-year-old trauma patient with an insignificant pneumothorax on the right who developed an intraoperative tension pneumothorax on the left side while undergoing thoracic spine stabilization surgery in the prone position. Management of an intraoperative tension pneumothorax requires prompt recognition and treatment; however, the prone position presents an additional challenge of readily accessing the standard anatomic sites for pleural puncture and air drainage.

Occult pneumothoraces in critical care: a prospective multicenter randomized controlled trial of pleural drainage for mechanically ventilated trauma patients with occult pneumothoraces

BACKGROUND

Patients with an occult pneumothoraces (OPTXs) may be at risk of tension pneumothoraces (TPTXs) without drainage or pleural drainage complications if treated.

METHODS

Adults with traumatic OPTXs and requiring positive-pressure ventilation (PPV) were randomized to pleural drainage or observation (one side only enrolled if bilateral). All subsequent care and method of pleural drainage was per attending physician discretion. The primary outcome was a composite of respiratory distress (RD) (need for urgent pleural drainage, acute/sustained increases in O2 requirements, ventilator dysynchrony, and/or charted respiratory events).

RESULTS

Ninety severely injured patients (mean [SD], Injury Severity Score [ISS], 33 [11]) were studied at four centers: Calgary (55), Toronto (27), Quebec (6), and Sherbrooke (3). Forty were randomized to tube thoracostomy, and 50 were randomized to observation. The risk of RD was similar between the observation and tube thoracostomy groups (relative risk, 0.71; 95% confidence interval, 0.40-1.27). There was no difference in mortality or intensive care unit (ICU), ventilator, or hospital days between groups. In those observed, 20% required subsequent pleural drainage (40% PTX progression, 60% pleural fluid, and 20% other). One observed patient (2%) undergoing PPV at enrollment had a TPTX, which was treated with urgent tube thoracostomy without sequelae. Drainage complications occurred in 15% of those randomized to drainage, while suboptimal tube thoracostomy position occurred in an additional 15%. There were three times (24% vs. 8%) more failures and more RDs (p = 0.01) among those observed with OPTXs requiring sustained PPV versus just for an operation, which increases threefold after a week in the ICU (p = 0.07).

CONCLUSION

Our results suggest that OPTXs may be safely observed in hemodynamically stable patients undergoing PPV just for an operation, although one third of those requiring a week or more of ICU care received drainage, and TPTXs still occur. Complications of pleural drainage remain unacceptably high, and future work should attempt to delineate specific factors among those observed that warrant prophylactic drainage.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Management of pediatric occult pneumothorax in blunt trauma: a subgroup analysis of the American Association for the Surgery of Trauma multicenter prospective observational study

BACKGROUND

Occult pneumothorax (OPTX) represents air within the pleural space not visible on conventional chest radiographs. Increased use of computed tomography has led to a rise in the detection of OPTX. Optimal management remains undefined.

METHODS

A pediatric subgroup analysis (age <18 years) from a multicenter, observational study evaluating OPTX management. Data analyzed were pneumothorax size, management outcome, and associated risk factors to characterize those that may be safely observed.

RESULTS

Fifty-two OPTX (7.3 ± 6.2 mm) in 51 patients were identified. None were greater than 27 mm; all those under 16.5 mm (n = 48) were successfully managed without intervention. Two patients underwent initial tube thoracostomy (one [21 mm] and the other with bilateral OPTX [24 mm, 27 mm]). Among patients under observation (n = 49), OPTX size progressed in 2; one (6.4mm) required no treatment, while one (16.5 mm) received elective intervention. Respiratory distress occurred in one patient (10.7 mm) who did not require tube thoracostomy. Nine received positive pressure ventilation; 8 did not have a tube thoracostomy. Twenty-four patients (51%) had one or more rib fractures; 3 required tube thoracostomy.

CONCLUSION

No pediatric OPTX initially observed developed a tension pneumothorax or adverse event related to observation. Pediatric patients with OPTX less than 16 mm may be safely observed. Neither the presence of rib fractures nor need for PPV alone necessitates intervention.

Initial management and resuscitation of severe chest trauma

Severe chest trauma, blunt or penetrating, is responsible for up to 25% of traumatic deaths in North America. Respiratory compromise is the most frequent dramatic presentation in blunt trauma, while injuries to the heart and great vessels pose the greatest risk of immediate death following penetrating trauma. More than 80% of patients will be managed with interventions that can be performed in the emergency department. This article reviews the presentation, diagnosis, and management of the most important thoracic injuries. A structured approach to the acutely unstable patient is proposed to guide resuscitation decisions.

Randomized controlled trials affecting polytrauma care

Trauma remains the leading cause of death in the world in patients under 45 years of age. The evaluation, resuscitation, and appropriate management of polytraumatized patients are paramount to successful outcomes. The advance of evidence-based medicine has had a powerful and positive impact on trauma care, even though the nature of many traumatic injuries lends itself poorly to study in a randomized fashion. During the initial management of bleeding patients, hypotensive resuscitation prior to surgical control has found strong support in the literature, and its use has been adopted by many surgeons. Head injury is the most common cause of traumatic death, and while high-level evidence is limited, adherence to management guidelines is associated with improved outcomes. For abdominal trauma, the concept of damage control surgery, while popular, has never been put to the test in a randomized controlled trial. Numerous randomized trials in the field of critical care have affected the management of severely injured patients, including intensive insulin therapy and low tidal volume ventilation in patients with compromised respiratory function. Finally, a multidisciplinary approach to trauma care in designated trauma centers allows for improved outcomes in polytraumatized patients.

Blunt traumatic occult pneumothorax: is observation safe?--results of a prospective, AAST multicenter study

BACKGROUND

An occult pneumothorax (OPTX) is found incidentally in 2% to 10% of all blunt trauma patients. Indications for intervention remain controversial. We sought to determine which factors predicted failed observation in blunt trauma patients.

METHODS

A prospective, observational, multicenter study was undertaken to identify patients with OPTX. Successfully observed patients and patients who failed observation were compared. Multivariate logistic regression was used to identify predictors of failure of observation. OPTX size was calculated by measuring the largest air collection along a line perpendicular from the chest wall to the lung or mediastinum.

RESULTS

Sixteen trauma centers identified 588 OPTXs in 569 blunt trauma patients. One hundred twenty-one patients (21%) underwent immediate tube thoracostomy and 448 (79%) were observed. Twenty-seven patients (6%) failed observation and required tube thoracostomy for OPTX progression, respiratory distress, or subsequent hemothorax. Fourteen percent (10 of 73) failed observation during positive pressure ventilation. Hospital and intensive care unit lengths of stay, and ventilator days were longer in the failed observation group. OPTX progression and respiratory distress were significant predictors of failed observation. Most patient deaths were from traumatic brain injury. Fifteen percentage of patients in the failed observation group developed complications. No patient who failed observation developed a tension PTX, or experienced adverse events by delaying tube thoracostomy.

CONCLUSION

Most blunt trauma patients with OPTX can be carefully monitored without tube thoracostomy; however, OPTX progression and respiratory distress are independently associated with observation failure.

Occult pneumothoraces truly occult or simply missed: redux

BACKGROUND

As utilization of computed tomography (CT) scans in the evaluation of trauma patients increases, pneumothoraces (PTXs) seen on CT but not on chest X-ray (CXR), known as occult PTXs (OPTXs), are becoming more prevalent. The incidence of PTXs simply missed on CXR among OPTXs is unclear. A previous retrospective review of CXRs at our institution generally confirmed the occult versus missed designation, but lower fidelity images may have biased this determination. Thus, we repeated this evaluation using the high-quality images and improved the methodology.

METHODS

The 70 Digital Imaging and Communications in Medicine (DICOM)-quality CXR images were randomly selected from two prospectively collected trauma databases including 22 normal, 5 overt PTX, and 43 study OPTX images. All CXR images were corroborated with multidetector CT imaging. Two blinded fellowship-trained radiologists reviewed and evaluated all the images on an IMPAX viewer.

RESULTS

All images were deemed "adequate" except for one CXR by a single reviewer. For PTX diagnosis, agreement was 60% for overt PTXs, 86% for normal CXRs, and 81% for study OPTXs, yielding a kappa statistic of 0.51 (95% confidence interval, 0.22-0.81) indicating moderate agreement. Considering only the cases where the reviewers agreed, 80% of the study OPTXs were truly occult versus missed (95% confidence interval, 63-92%). In the 7 missed PTXs, subcutaneous emphysema (5), pleural line (3), and deep sulcus sign (2) were detected.

CONCLUSION

We estimate that 80% of PTXs considered occult in the trauma room were truly occult. The most common missed sign was subcutaneous emphysema. PTXs are poorly assessed by CXR, and accurate diagnosis should focus on other imaging modalities.

Management of traumatic occult pneumothorax

STUDY OBJECTIVE

Occult pneumothorax (OPTX) is defined as a pneumothorax seen on computed tomography but not apparent on supine plain radiography. Though increasingly common, the acute management of OPTX after trauma remains controversial. This evidence-based review evaluates the existing evidence regarding the safety and efficacy of observation as compared to tube thoracostomy (TT) for management of OPTX in emergency department trauma patients.

METHODS

The authors searched MEDLINE, EMBASE, the Cochrane Library, and other databases.

INCLUSION CRITERIA

studies of adult or pediatric trauma victims at first presentation after blunt or penetrating injury (population), randomized to observation (intervention) or TT (comparison). Studies that enrolled patients on positive pressure ventilation were included but those that enrolled hemodynamically unstable patients were excluded. Outcomes of interest included progression of OPTX, mortality, complications (pneumonia, empyema), and length of stay in hospital and intensive care unit (ICU).

RESULTS

A total of 411 articles were identified. After applying the inclusion/exclusion criteria, 3 randomized trials enrolling a total of 101 patients were found to have acceptable quality standards suitable for analysis. The included studies did not reveal any significant difference between observation and TT in regards to progression of OPTX, risk of pneumonia, or length of stay in hospital or ICU. Mortality risk and empyema rate were also not different in the single studies that reported those outcomes.

CONCLUSION

The existing evidence leads to the conclusion that observation is at least as safe and effective as tube thoracostomy for management of occult pneumothorax.

Opening Pandora’s box: the potential benefit of the expanded FAST exam is partially confounded by the unknowns regarding the significance of the occult pneumothorax

Introduction

Point of care (POC) ultrasound brings another powerful dimension to the physical examination of the critically ill. A contemporary challenge for all care providers, however, is how to best incorporate ultrasound into contemporary algorithms of care. When POC ultrasound corroborates pre-examination clinical suspicion, incorporation of the findings into decision-making is easier. When POC ultrasound generates new or unexpected findings, decision-making may be more difficult, especially with conditions that were previously not appreciated with older diagnostic technologies. Pneumothoraces (PTXs), previously seen only on computed tomography and not on supine chest radiographs known as occult pneumothoraces (OPTXs), which are now increasingly appreciated on POC ultrasound, are such an example.

Methods

The relevant literature concerning POC ultrasound and PTXs was reviewed after an electronic search using PubMed supplemented by ongoing research by the Canadian Trauma Trials Collaborative of the Trauma Association of Canada.

Results

OPTXs are frequently encountered in the critically injured who often require mechanical ventilation with positive pressure breathing (PPB). Standard recommendations for post-traumatic PTXs and the setting of PPB mandate chest drainage, recognizing a significant rate of complications related to this procedure itself. Whether these standard recommendations generated in response to obvious overt PTXs apply to these more subtle OPTXs is currently unknown, and evidence-based recommendations regarding appropriate therapy are impossible due to the lack of clinical studies.

Conclusions

OPTXs are a condition that illustrates how incorporation of POC ultrasound findings brings further responsibilities to critically appraise the significance of these findings in terms of patient outcomes and overall care. Adequately powered and adequately followed-up clinical trials addressing the treatment are required.