Date: December 28th, 2021

Reference: 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.

Guest Skeptic: Dr. Chris Root is a second-year resident physician in the Department of Emergency Medicine at the University of New Mexico Health Sciences Center in Albuquerque, NM. He is also a resident flight physician with UNM’s aeromedical service, UNM Lifeguard. Prior to earning his MD, he worked as a paramedic in the New York City 911 system.

CaseA 43-year-old male presents to your emergency department (ED) the day after being involved in an all-terrain vehicle (ATV) accident. He reports he was riding his ATV along an embankment when it rolled, landing on top of him briefly. He did not seek medical attention at the time of the incident, but he has had persistent chest wall pain and worsening shortness of breath since yesterday evening. He is hemodynamically stable, oxygen saturation is 91% on room air, physical exam reveals ecchymosis and tenderness over the right chest wall with diminished right sided lung sounds. CT scans reveal multiple right sided rib fractures and a hemothorax estimated to measure 500cc with no additional injuries.

Background:  We have discussed chest tubes a couple of times on the SGEM. This is usually with the master himself, Dr. Richard (Thoracic Rick) Malthaner. The first time was looking at a study about where to put the chest tube in a trauma patient. It turns out location (high or low) does not matter. The most important thing is placing the chest tube in the triangle of safety in the plural space (SGEM#129).

The other episode on chest tubes looked at conservative vs interventional treatment for spontaneous pneumothorax (SGEM#300). This randomized controlled trial demonstrated that conservative management was non-inferior to placing a chest tube in a patient with a large first-time spontaneous pneumothorax.

Another SGEM episode we did looked at the location of needle decompression for tension pneumothorax (SGEM#339). This was done with our good friend and frequent guest skeptic Dr. Robert Edmonds. This observational study did not support the claim that the second intercostal space-midclavicular line is thicker than the fourth/fifth intercostal space-anterior axillary line.

This new SGEM episode looks at the size of chest tubes needed to successfully treat a traumatic hemothorax. Traditionally, these are treated by inserting a large bore chest tube (LBCT). There is increasing evidence supporting the use of smaller, percutaneously inserted chest tubes or pigtail catheter (PC) for the drainage of pleural effusions and pneumothoraces as well as some evidence of their efficacy for hemothorax.

Clinical Question: Are small (14fr) pigtail catheters as effective as large (28-32 fr) chest tubes for the treatment of hemodynamcially stable patients with traumatic hemothorax?

Reference: 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.

  • Population: Hemodynamically stable adult patients 18 years or older suffering traumatic hemothorax or hemopneumothorax requiring drainage at the discretion of the treating physician.
    • Exclusions: Emergent indication, hemodynamic instability, patient refuses to participate, prisoner or pregnancy
  • Intervention: Placement of small (14 fr PC) chest tube using a percutaneous seldinger technique
  • Comparison: Placement of a large (28-32 fr LBCT) chest tube using a traditional surgical thoracostomy
  • Outcome:
    • Primary Outcome: Failure rate defined as radiographically apparent hemothorax after tube placement requiring an additional intervention such as second tube placement, thrombolysis or video-assisted thorascopic surgery
    • Secondary Outcomes: Insertion complication rate; drainage output (30 minutes, 24-hour, 48-hour, and 72-hour); hospital course outcome up to 30 days (total tube days, ICU LOS, hospital LOS, and ventilator days); and insertion perception experience (IPE) score (1-5 score subjective score,1 – it was okay to 5 – it was the worst experience of my life).
  • Trial: Multicenter, non-inferior, unblinded, randomized, parallel assignment comparison trial

Authors’ Conclusions: Small caliber 14-Fr PCs are equally as effective as 28- to 32-Fr chest tubes in their ability to drain traumatic HTX with no difference in complications. Patients reported better IPE scores with PCs over chest tubes, suggesting that PCs are better tolerated.”

Quality Checklist for Randomized Clinical Trials:

  1. The study population included or focused on those in the emergency department. Yes
  2. The patients were adequately randomized. Yes
  3. The randomization process was concealed. Yes
  4. The patients were analyzed in the groups to which they were randomized. Yes
  5. The study patients were recruited consecutively (i.e. no selection bias). Unsure
  6. The patients in both groups were similar with respect to prognostic factors. Yes
  7. All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No
  8. All groups were treated equally except for the intervention. Unsure
  9. Follow-up was complete (i.e. at least 80% for both groups). Yes
  10. All patient-important outcomes were considered. Yes
  11. The treatment effect was precise enough to be clinically significant. Yes
  12. Financial conflicts of interest. Yes

Results: There were 222 eligible patients identified over five years. The final cohort consisted of 119 patients (56 PC and 63 LBCT). The mean age was 55 years, 82% were male, 81% blunt trauma and median time to tube placement was 1 to 2 days from injury.

Key Result: Small percutaneous catheters were non-inferior to large open chest tube for traumatic hemothorax

  • Primary Outcome: Failure rate between PC and LBCT for the drainage of traumatic hemothorax 11% vs 13% (p=0.74).
  • Secondary Outcomes: There were two insertion-related complications one from each group (bleeding from PC necessitated a thoracotomy and extra pleural position from chest tube placement required another tube placement). There were two deaths, one from each group (PC group had a PE on postinjury day 10 and the tube had already been removed and chest tube group had a nontrauma-related death at an outside institution). No statistical difference between PC and LBCT in terms of drainage tube output except at 30 minutes. No statistical difference in hospital course (tube days, ICU LOS, total hospital LOS or ventilatory days). Patients reported better IPE scores in the PC group compared to the LBCT group.

1. Selection Bias: There was no explicit statement that patients were consecutively recruited into the trial. They identified 222 eligible patients over five years. There were 102 excluded with 27 for “MD preference”.This means 27/102 (26%) of exclusions were for a subjective reason. This could have introduced some selection bias into the trial.

2. Exclusion of Hemodynamically Unstable Patients: Hemodynamically unstable trauma patients were excluded from study enrollment. Open thoracostomy and the placement of a LBCT is still considered by many to be the primary treatment for the evacuation of hemothorax in the hemodynamcailly unstable trauma patient. The authors did not seek to deviate from that idea in this study. However, they do allude to anecdotal experience placing PCs in hemodynamically unstable patients, and the output from PCs in the first hour was greater than that from LBCT in their trial, but further studies are needed to investigate the utility of PCs in hemodynamically unstable trauma patients. The exclusion of hemodynamically unstable patients could also explain the lower than anticipated failure rate which will be discussed later.

3. Patient Oriented Outcome: Tube failure rate is a simple, dichotomous, and clinically important primary outcome. However, the IPE score is a critical patient-oriented outcome (POO) that should be considered when managing these patients. The lead author, Dr. Kulvatanyou, alludes to having had friends and family members who have undergone LBCT placement express how horrible it was. Although the IPE scale developed by the investigators was not externally validated it is a straightforward and effective means of comparing the subjective experience of patients receiving either intervention. If you had a traumatic hemothorax, would you like the big tube or the small tube?

4. Low Overall Failure Rates: This study reports failure rates of 11% and 13% for PCs and LBCT respectively. These figures are significantly lower than a rate of 28.7% reported in a recent multi-institutional study from the Eastern Association for the Surgery of Trauma (EAST). The authors comment that this may be because their study excluded patients in extremis who may have additional injuries or require a level of procedural urgency that predisposes them to complications, however it is interesting to note that the study population in this trail had a mean hemothorax volume of 612mL vs 191 mL is the EAST study indicating that volume of blood did not appear to influence rate of failure compared to what has been published elsewhere (Prakash et al 2020).

5. Stopped Early: This is a multi-center RCT building on this groups previously published single center experience using PCs for the treatment of traumatic hemothorax (Kulvatunyou JTACS 2012). Despite enrolling at four sites for five years, they only enrolled 119 total patients. The authors initially estimated that they would have had to enroll 95 patients in each arm to have adequate power to detect a 15% absolute difference in efficacy between PCs and LBCTs. This was also based on the assumption of a failure rate of 15% for PC and 30% for LBCT.

Unfortunately, due to slow enrollment and the disruption to research caused by the COVID19 pandemic the authors stopped the study early after enrolling 56 patients in the PC arm and 63 patients in the LBCT arm. They report they conducted an interim analysis prior to stopping enrollment and their primary endpoint still met the non-inferior margin.

Comment on Authors’ Conclusion Compared to SGEM Conclusion: The authors concluded that PC are “equally” as effective as LBCTs for the evacuation of traumatic hemothorax and that patients tolerate the placement of PCs better than LBCTs. A friendly amendment would be to say that PCs are non-inferior to LBCT and that patients prefer PC. They would have needed to show the 95% CI and demonstrate equivalence to claim “equally” effective. We have reached out to the authors to see if we can get this information and will update the blog if/when it becomes available.

SGEM Bottom Line: It is reasonable to offer a pigtail catheter instead of a large bore chest tube for the evacuation of a traumatic hemothorax in a hemodynamically stable patient.

Case Resolution: The patient is consented for the placement of a PC in the ED. He is admitted to the trauma service for monitoring and pain management. The PC is removed on hospital day three and the patient is discharged on hospital day five.

Dr. Chris Root

Clinical Application: This trial provides more information that bigger is not necessarily better means of treating traumatic hemothorax.

What Do I Tell the Patient?  You have a collection of blood between your chest wall and lung.  This is called a hemothorax. To relieve your discomfort and prevent your breathing from becoming worse we recommend inserting a tube to drain the blood out. Traditionally this was done with a large tube. However, there’s evidence that it is effective, safe, and more comfortable for patients to use a smaller tube. This smaller tube is called a pigtail catheter. We would give you numbing medicine and some sedation to make it as comfortable as possible. You will be admitted to the hospital for monitoring and pain management while it drains. The tube will stay in place for a few days. Would you like the small tube or the big tube?

Keener Kontest: Last weeks’ winner was Dr. Lauren Onofrey from the University of Washington. She knew Anthony Edwards narrated the documentary 24/7/365 and played Dr. Greene on the TV show ER.

Listen to the SGEM podcast for this weeks’ question.  If you know, then send an email to with “keener” in the subject line. The first correct answer will receive a cool skeptical prize.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics Guide to Emergency Medicine.