Background: Optimal management of pneumothorax and hemothorax with chest thoracostomy has been widely debated over the last decade. We no longer question the utility of pigtail catheters for pneumothorax and now ask whether a catheter has to be placed at all (REBEL EM). We’ve moved towards smaller (28-32 Fr) chest tubes for the management of traumatic hemothorax as well. However, we’ve resisted smaller catheters in hemothorax for fear of complications and retained hemothorax. While there is limited data (Bauman 2018) for the use of 14 Fr pigtail catheters instead of large-bore chest tubes, additional research is needed to shift the treatment paradigm.
Article: Kulvatunyou N 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 Acute Care Surg. 2021;91(5):809-813. [PMID: 33843831]
Clinical Question: Is a 14 Fr pigtail catheter noninferior to a 28–32 Fr chest tube for managing traumatic hemothorax in hemodynamically stable patients?
What They Did:
- Multicenter open-label randomized clinical trial design
- Randomization allocation was computer generated and created block sizes of four
- Investigators sent assignments to each participating center electronically in a concealed folder
- Researchers enrolled patients from July 2015 to September 2020.
- Patients were randomized to pigtail catheter (14 Fr) or chest tube (28-32 Fr).
Population:
- Inclusion Criteria: ≥18 years old with traumatic hemothorax (HTX) or hemopneumothorax (HPTX) requiring drainage.
- Exclusion Criteria:
-
- Hemodynamic instability
- The catheter was placed in the operating room
- The patient declined to participate or researchers were unable to obtain consent
Intervention:
- 14 Fr pigtail catheter
Control:
- 28–32 Fr large-bore chest tube
Outcomes:
- Primary outcome: Failure rate for the drainage catheter
- Retained Hemothorax requiring additional intervention including a second catheter, thrombolysis, video-assisted thoracoscopy surgery.
- Secondary outcomes:
- Output at 30 min, 24-hours, 48-hours, 72 hours
- Total tube days
- Insertion-related complications
- Ventilator days
- ICU length of stay
- Hospital length of stay
- Insertion Perception Experience (IPE)
Results:
- 222 patients screened
- 120 patients enrolled
- 57 patients randomized to pigtail arm
- 63 patients randomized to chest tube arm
- 1 patient in the pigtail arm was excluded after enrollment because the patient had a pleural effusion
Strengths:
- Investigators ask a clinically relevant question
- Randomized study design increases the validity of the results
- The patients’ demographics and baseline characteristics appear to be balanced in each arm
Limitations:
- While this is a multicenter study, most patients were enrolled from 1 site limiting generalizability.
- Both patients and treating physicians were unblinded to the study arm by nature of the clear differences between the catheters
- The primary outcome, tube failure while clinically relevant, is a disease-oriented outcome
- IPE is not an externally validated assessment tool
- The study population appears to be a convenience sample
- The decision to place a catheter was at the discretion of the treating physician, so there is likely some additional selection bias.
- 7 of 102 patients excluded from eligibility were excluded due to MD preference, which introduces significant selection bias.
- No objective definition of “hemodynamic instability” or “extremis” for excluded patients included patients, which contributes to selection bias
- The noninferiority margin of 15% is very wide.
- Tube failure rates were much lower than anticipated
- The trial was stopped early due to a prolonged period of enrollment and investigators only managed to enroll 60 patients in each arm while they planned for 95.
- There was no mention of predetermined stopping criteria or interim analysis
Discussion:
- Pain Assessment
- The IPE tool used by investigators, like nearly all pain scores, is subjective and hasn’t been externally validated.
- The investigators did not standardize the dosage, quantity, or type of local and systemic analgesia administered and we are given little information about the analgesics utilized. Intuitively it seems sensible that a large-bore chest tube placed with a surgical technique is more painful than a pigtail catheter placed over a guidewire. However, it’s possible the difference in IPE scores could be the result of differences in analgesic administration in patients treated with pigtail catheters.
- Noninferiority Trials
- Noninferiority Trials, covered here on REBEL EM, are useful when the new treatment offers a distinct advantage over the standard treatment. While the evidence in support of pigtail catheters over chest tubes for pneumothorax is clear, it remains to be determined if pigtails are beneficial in hemothorax. In addition, the noninferiority margin is very wide. The wider the margin the easier it is to show noninferiority.
- Selection bias
- There is no mention of whether patients were enrolled consecutively. We know nothing of the patients who were possibly eligible for inclusion and not enrolled or whether these patients represent a typical cohort of the population. In addition, trauma surgeons could choose to place a CT over a PC and did so in >25% of excluded patients, which also adds to selection bias.
- Truncated RCTs
- Trials can be terminated early for a few reasons including apparent benefit, harm, or in this case a prolonged period of enrollment. Truncated RCTs are at risk of overestimating results.
- Investigators estimated a failure rate of approximately 30% but observed a much lower rate of 11% and 13%.
- The combination of difficulty enrolling patients and a lower than anticipated failure rate renders the study underpowered.
Author’s Conclusion: “In conclusion, in this multi-institution RCT study, we found that there was no difference in terms of the failure rate between 14-Fr PCs and large-caliber (28–32 Fr) chest tubes in their ability to drain traumatic HTX. We also found that PC patients reported a better tube-insertion experience, meaning less pain and agony than chest tube patients. We suggest that, if more institutions would consider adopting PC for HTX drainage in a non-emergency setting and report their institutional experiences, more knowledge can be gained and shared among clinicians.”
Our Conclusion: The data presented in this paper add to the growing body of evidence in support of smaller catheters over large-bore chest tubes for the management of hemothorax. However, we need larger multicenter trials before adopting wholesale changes to our clinical practice.
References:
- Kulvatunyou N, Bauman ZM, Zein Edine SB, 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 Acute Care Surg. 2021;91(5):809-813. PMID 33843831
- Bauman ZM, Kulvatunyou N, Joseph B, et al. Randomized Clinical Trial of 14-French (14F) Pigtail Catheters versus 28-32F Chest Tubes in the Management of Patients with Traumatic Hemothorax and Hemopneumothorax. World J Surg. 2021;45(3):880-886. PMID: 33415448
- Bauman ZM, Kulvatunyou N, Joseph B, et al. A Prospective Study of 7-Year Experience Using Percutaneous 14-French Pigtail Catheters for Traumatic Hemothorax/Hemopneumothorax at a Level-1 Trauma Center: Size Still Does Not Matter. World J Surg. 2018;42(1):107-113. PMID: 28795207
For More on This Topic Checkout:
- The Skeptics Guide to Emergency Medicine:SGEM#355: Bigger Isn’t Better When it Comes to Chest Tubes
- St Emelyn’s Blog: Can we use smaller pigtail drains in traumatic haemothorax?
Post-Peer Reviewed By: Anand Swaminathan, MD (Twitter: @EMSwami) and Salim R. Rezaie, MD (Twitter: @srrezaie)
