Tube Thoracostomy for Hemothorax - Is a Tiny Tube Just Fine?
/Kulvatunyou et al. The small (14 Fr) percutaneous catheter (P-CAT) versus large (28–32 Fr) open chest tube for traumatic hemothorax: A multicenter randomized clinical trial. J Trauma and Acute Care Surgery. November 2021.
Background
The authors of this paper aimed to demonstrate that a 14-Fr percutaneous catheter (“pigtail”) is equally as effective for drainage of traumatic hemothorax as traditional chest tube. This is in contrast with the historical management of traumatic hemothorax where a large-bore chest tube is dogmatically placed. These chest tubes can be as large as a 36-40 Fr, but, more commonly, a 28-32 Fr tube is placed to facilitate drainage of a traumatic hemothorax. The presumption is that these tubes with larger internal diameter allow for better drainage of blood from the chest. The authors of this paper point out that blood will flow through a tube of any size as long as it is not clotted, and this paper is built on the authors’ previous work showing non-inferiority in a prospective study and a single-center randomized controlled trial showing great success with the 14-Fr pigtail catheter.
In this study, the authors hypothesized that 14-Fr pigtail catheters are non-inferior to traditional chest tubes in the drainage of traumatic hemothorax. They also anticipated that there would be less patient discomfort with pigtail catheters and created a rating system to assess this.
Methods
This was a multi-center, non-inferiority, unblinded, randomized controlled trial. Patients were included if they were >18 years, hemodynamically stable, and suffered a traumatic hemothorax or hemopneumothorax that required drainage. Patients were excluded if they were hemodynamically unstable, emergent placement was required, the tube was placed in the operating room, or the patient was unable to consent or refused to participate.
The intervention in question was the placement of a 14-Fr pigtail catheter by Seldinger technique. This was compared to the standard of 28- to 32-Fr chest tube using traditional thoracostomy. Both were placed at bedside by supervising trauma surgeon and/or resident at the 4th or 5th intercostal space in the anterior or mid-axillary line. Lidocaine was injected for local anesthesia and the physician’s choice of IV analgesia was also used. After verification of placement with radiography and connection to -20 mmHg, the remainder of the tube management was left to the discretion of the attending physician.
The primary outcome was failure rate of the chest tube or pigtail catheter. This was defined as a radiographically apparent retained hemothorax after placement requiring additional intervention which included placement of additional tube, thrombolysis, or video-assisted thoracoscopic surgery (VATS). Secondary outcomes included drainage volume at 30 minutes, 24 hours, 48 hours, and 72 hours; total days with the tube in place; complications from insertion; ventilator days; ICU length of stay; hospital length of stay.
As an additional secondary outcome, the authors also created a score to assess patient’s perception of the procedure called the “insertion perception experience” score or IPE score which was assessed 30 minutes after tube insertion. This ranged from 1-5 and aimed to capture the patient’s sentiment during the insertion process:
It was okay, I can tolerate it, I can do it again
It was okay, but I do not want to go through it again
It was a bad experience for me
It was a worse experience for me
It was the worst experience of my life!
This score is not externally validated and was created by these authors solely for this project.
A pre-specified non-inferiority margin was calculated, and the authors estimated 95 patients would be required in each arm to adequately power the study. However, the study was eventually terminated early with the non-inferiority parameter for the primary outcome of tube failure still met.
Results
Over 5 years, 222 patients were screened and 120 were ultimately enrolled (Figure 1). 57 patients were randomized to pigtail catheters and 63 to large bore chest tubes. There were no statistically significant differences in baseline characteristics between the two groups. The majority of patients were middle-aged males with blunt trauma (Table 1).
For the primary outcome, failure rate of 14-Fr pigtail catheter vs. 28- to 32-Fr large bore chest tube was 11% vs 13% (p=0.74). Pigtail catheters had larger output at 30 minutes and 24 hours, but eventually daily output was the same at 48 and 72 hours when compared to large bore chest tubes. There was no statistically significant difference in intervention failure rate, number of tube days, complication rate, progression to VATS, ventilator days, ICU days, or hospital length of stay between the two groups (Table 3).
For the secondary outcome of patient perception, the median IPE score for patients who had undergone pigtail catheter insertion was 1 (IQR 1-2) compared to a median of 3 for those who had undergone chest tube insertion (IQR 2-5) (p <0.001).
Discussion
As it relates to the primary outcome of failure rate, this multi-center RCT demonstrates non-inferiority of 14-Fr pigtail catheters when compared to 28- to 32-Fr chest tubes for drainage of traumatic hemothorax in hemodynamically stable adult patients.
Of the measured secondary outcomes, there was no significant difference aside from the measured patient experience. Although the authors’ IPE score is not externally validated, it is a pragmatic assessment of discomfort and pain on a 5-point scale. The outcomes are significantly different between the two as shown above, and it would be a reasonable conclusion that patients prefer the insertion experience of pigtail catheters over standard chest tubes.
Another interesting note from this study’s data is that the failure rates of 11% and 13% are considerably lower than the ~30% average failure rate of chest tubes reported by the Eastern Association for the Surgery of trauma Multi-institutional Trial. The authors suggest that perhaps this is related to the fact that patients in extremis were excluded and therefore less severely injured with fever ventilator and ICU days, leading to fewer complications.
Is this study practice changing? Maybe. It is a high-quality study with some important limitations (below), and it’s possible that in the near future, the practice of placing 14-Fr pigtail catheters for traumatic hemothorax in stable patients may become more widespread. Although your practice may be guided by institutional variables outside your control, it would be reasonable to discuss the risks and benefits of each option with your patients and include the findings from this paper in that discussion.
Limitations
This study has a few very important limitations. First, hidden in Figure 1, is the breakdown of patients who were screened and eventually excluded from study population. 26% of those excluded were for “physician preference” and there is no further breakdown which may have created some bias in patient selection. Also excluded were hemodynamically unstable patients, limiting the application of these findings to that population. It is interesting that the output in the first 30 minutes and 24 hours was greater in the 14-Fr group, potentially favoring this option in the hemodynamically unstable patient who may have tension physiology. Familiarity with these catheters is less than with standard chest tubes, however. It may likely be a subject of future exploration for these authors to include that population in the intervention group.
Additionally, as discussed above, the IPE score is not externally validated as a rating scale. While this makes it less generalizable, it is still a very patient-oriented, useful metric. It’s also interesting that the primary author on the paper shares experiences from family and friends who had had chest tubes placed and these have bene painful. One could argue that this could introduce bias as well. At the same time, though, all good research starts somewhere – why not use the inspiration from family and friends’ negative experiences?
The authors do disclose that part of the funding for this study came from Cook Medical, LLC which is the company that manufactures the 14-Fr pigtail catheter that was used. The authors indicate that the company had no role in the study, but this sort of thing can occasionally raise some eyebrows. Also, although this was a “multi-center” RCT the breakdown of the sites in Table 2 indicates that some of the sites enrolled far more patients than others. For example, Site 4 only enrolled four total patients over the course of 5 years. These data may then be weighted significantly to favor the practice of the dominant sites despite the equivalent patient population demographic breakdowns.
Lastly, one of the most important exclusions is that this study was stopped early. The authors indicate a combination of slower than expected enrollment coupled with the Covid-19 pandemic. While they did not meet their pre-specified enrollment of 95 in each arm for adequate power, the fact that both groups had lower treatment failure rates than expected allowed for the non-inferiority threshold for their primary outcome to be reached to be reached despite this.
Authorship
Written by: Anthony Fabiano, MD, PGY-3 University of Cincinnati Department of Emergency Medicine
Peer Review, Editing, Posting by: Jeffery Hill, MD MEd, Associate Professor, University of Cincinnati Department of Emergency Medicine
Cite As
Fabiano, A. Hill, J. (August 17, 2022) Tube Thoracostomy for Hemothorax - Is a Tiny Tube Just Fine? TamingtheSRU. https://www.tamingthesru.com/blog/journal-club/tube-thoracostomy-for-hemothorax-is-a-tiny-tube-just-fine
