The small (14 Fr) percutaneous catheter (P-CAT) versus large (28-32 Fr) open chest tube for traumatic hemothorax: a multicenter randomized clinical trial
Kulvatunyou N, Bauman ZM, Zein Edine SB, et al. J Trauma Acute Care Surg. 2021;91(5):809-813.
According to traditional teaching, hemothoraces require large-bore, 36- to 40-French chest tubes (CTs), because a large lumen is necessary for blood to flow through. This strategy works for evacuating blood but comes at the cost of a larger hole in the chest wall and significantly more pain for patients. The authors of this study claim that nonclotted blood flows without severe restriction through a smaller catheter as well as it does through a chest tube; however, they note that clotted blood cannot flow through either. Over the past decade, several articles have examined outcomes for patients with ever-smaller CTs: initially 28-French, then 20-French, and ultimately 14-French pigtail catheters (PTs). All these previous studies showed similarly favorable outcomes regardless of CT size, but all were observational; therefore selection bias could potentially have confounded the relationship between size and success.
The authors of this study conducted a multicenter RCT of PT vs CT for traumatic hemopneumothorax.
The primary outcome was the failure rate, defined as radiographically apparent hemothorax after tube placement that required an additional procedure. The secondary outcomes were initial CT output, hospital length of stay, and importantly the patient-reported experience score.
The study was set up with a noninferiority design, but the statistical methods and data reporting do not meet the highest standards.
The authors needed 95 patients in each arm to demonstrate noninferiority but, because of a variety of factors including the COVID-19 pandemic, the study was terminated early. However, the authors claim that they still met the criteria for noninferiority, despite not actually showing the margins.
Any adult with traumatic hemothorax was eligible. Generally, the authors used a threshold of an estimated 300 cc of blood, but the decision of whether to place the CT was left to the treating physician. After informed consent was obtained, the patients were randomized to 14-French PTs or 28- to 32-French CTs, which were placed in the usual manner without procedural sedation.
Over a 5-year period, 57 patients were randomized to PTs, and 63 were randomized to CTs across the 4 study sites. Most enrolled patients came from 1 site.
The mean patient age was 55, 80% of the patients were men, and almost all had blunt trauma, with an initial average CT output of 500 cc. The failure rate was 11% in the PT group and 13% in the CT group, which were statistically similar. Almost all other outcomes were also similar, except for the patient-reported insertion perception score, which was much higher in the CT group than the PC group. The median score for the CT group translated to “it was a bad experience for me” (score 3), whereas the PC group’s median score was 1, which translated to “it was OK, I can tolerate it, and I can do it again.”
This is a relatively small study of relatively stable patients who provided consent to participate (ie, not necessarily the typical ED trauma patients, who may have acute large hemothorax). Second, this was essentially a single-center study, thus substantially limiting the generalizability of the findings. Nonetheless, the results do offer additional support to the growing notion that CT size does not matter. Because this study is an RCT, it is likely to remain the best available evidence for a while.
EDITOR’S COMMENTARY: This is a limited RCT suggesting that small French PTs are sufficient for somewhat stable hemothoraces. These data are intriguing but probably require more extensive validation before being widely adopted.