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

Conservative management versus invasive management of significant traumatic pneumothoraces in the emergency department (the CoMiTED trial): a study protocol for a randomised non-inferiority trial

INTRODUCTION

Traumatic pneumothoraces are present in one of five victims of severe trauma. Current guidelines advise chest drain insertion for most traumatic pneumothoraces, although very small pneumothoraces can be managed with observation at the treating clinician's discretion. There remains a large proportion of patients in whom there is clinical uncertainty as to whether an immediate chest drain is required, with no robust evidence to inform practice. Chest drains carry a high risk of complications such as bleeding and infection. The default to invasive treatment may be causing potentially avoidable pain, distress and complications. We are evaluating the clinical and cost-effectiveness of an initial conservative approach to the management of patients with traumatic pneumothoraces.

METHODS AND ANALYSIS

The CoMiTED (Conservative Management in Traumatic Pneumothoraces in the Emergency Department) trial is a multicentre, pragmatic parallel group, individually randomised controlled non-inferiority trial to establish whether initial conservative management of significant traumatic pneumothoraces is non-inferior to invasive management in terms of subsequent emergency pleural interventions, complications, pain, breathlessness and quality of life. We aim to recruit 750 patients from at least 40 UK National Health Service hospitals. Patients allocated to the control (invasive management) group will have a chest drain inserted in the emergency department. For those in the intervention (initial conservative management) group, the treating clinician will be advised to manage the participant without chest drain insertion and undertake observation. The primary outcome is a binary measure of the need for one or more subsequent emergency pleural interventions within 30 days of randomisation. Secondary outcomes include complications, cost-effectiveness, patient-reported quality of life and patient and clinician views of the two treatment options; participants are followed up for 6 months.

ETHICS AND DISSEMINATION

This trial received approval from the Wales Research Ethics Committee 4 (reference: 22/WA/0118) and the Health Research Authority. Results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRCTN35574247.

Mechanical Ventilation Does Not Predict Pneumothorax Observation Failure in the Severely Injured

BACKGROUND

Observative management of small traumatic pneumothoraces (PTX) has been shown to decrease chest tube utilization in non-mechanically ventilated patients without compromising outcomes. This approach could be used in mechanically ventilated (MV) patients, though many feel these patients are at increased risk of observation failure.

METHODS

A single center retrospective study of all adults undergoing observation of a computed tomography (CT) diagnosed PTX from 2015-2019. Patients with chest tube placement within 4-hours of arrival, concurrent hemothorax, or death within 24-hours were excluded. Observation failure was defined as chest tube placement.

RESULTS

Of 340 patients, 64 were on MV. The groups were of similar age, BMI, underlying pulmonary comorbidities, and PTX size (10.1 mm vs 8.8 mm, P = .20). The MV group was more severely injured (ISS [25+] [60.9% vs 11.2%, P < .001]). There was no difference in observation failure rates by MV status overall (6.3% vs 5.1%, P = .75) or by PTX size (<15 mm [5% vs 2.2%, P = .37], <20 mm [4.8% vs 3.1%, P = .45], <25 mm [4.8% vs 4.1%, P = .73], <30 mm [4.8% vs 4.1%, P = .73], <35 mm [4.8% vs 4.7%, P = 1.00]). MV was not an independent predictor of observation failure on multivariable analysis (OR .64, 95% CI .18-2.20), though PTX size was (OR 1.11, 95% CI 1.05-1.17). When comparing those who failed vs those who did not, the only difference was PTX size (9.34 mm vs 19.41 mm, P < .001).

CONCLUSION

MV is not an independent predictor of PTX observation failure. While PTX size appears to play a role, further studies are needed to outline safe parameters for observation in those undergoing MV.

Complications associated with pre-hospital open thoracostomies: a rapid review

Background

Open thoracostomies have become the standard of care in pre-hospital critical care in patients with chest injuries receiving positive pressure ventilation. The procedure has embedded itself as a rapid method to decompress air or fluid in the chest cavity since its original description in 1995, with a complication rate equal to or better than the out-of-hospital insertion of indwelling pleural catheters. A literature review was performed to explore potential negative implications of open thoracostomies and discuss its role in mechanically ventilated patients without clinical features of pneumothorax.

Main findings

A rapid review of key healthcare databases showed a significant rate of complications associated with pre-hospital open thoracostomies. Of 352 thoracostomies included in the final analysis, 10.6% (n = 38) led to complications of which most were related to operator error or infection (n = 26). Pneumothoraces were missed in 2.2% (n = 8) of all cases.

Conclusion

There is an appreciable complication rate associated with pre-hospital open thoracostomy. Based on a risk/benefit decision for individual patients, it may be appropriate to withhold intervention in the absence of clinical features, but consideration must be given to the environment where the patient will be monitored during care and transfer. Chest ultrasound can be an effective assessment adjunct to rule in pneumothorax, and may have a role in mitigating the rate of missed cases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00976-1.

Management of Pneumothorax

Pneumothorax is a common medical condition encountered in a wide variety of clinical presentations, ranging from asymptomatic to life threatening. When symptomatic, it is important to remove air from the pleural space and provide re-expansion of the lung. Additionally, patients who experience a spontaneous pneumothorax are at high risk for recurrence, so treatment goals also include recurrence prevention. Several recent studies have evaluated less invasive management strategies for pneumothorax, including conservative or outpatient management. Future studies may help to identify who is greatest at risk for recurrence and direct earlier definitive management strategies, including thoracoscopic surgery, to those patients.