Competence and Chest Tubes

There is a model of skills acquisition and performance that nicely sums up how you get good at doing something. I forget the name, and I used to teach it to outdoor education students, but I was never good at remembering names (or numbers). The curve starts at “unconscious incompetence” - the inability to do something well and the lack of insight to know that there is a better way of doing it. 

In medicine I suppose a good example might be learning to take a history from a patient. Not knowing there is a useful structure and framework to getting all the salient information from a patient, a medical student or lay person would be forgiven for asking a few simple questions and not getting the key relevant details.  

The next level is “conscious incompetence”. You now understand that you are not yet competent at the task you are performing, you have insight. At medical school we are necessarily moved rapidly from “unconscious” to “conscious” performance; there’s not much point sending your medical students blindly digging for information on why a patient has turned up in hospital, without at least arming them with the understanding that we want to know about family, social, past medical, drug histories, as well as allergies smoking and drug / alcohol consumption. As a medical student armed with this knowledge I was aware of what I needed to do, and very aware of times when I seemed not to be very good at it.  

With experience, training and reflection on personal performance, you can reach a state of “conscious competence”. You can perform the task at hand well, but it requires a lot of your concentration, energy, and “bandwidth”. You get the job done, but it feels like hard work. You are aware of when you get it right and when you get it wrong, but don’t yet have “mastery”. 

Lastly, “unconscious competence” may be achieved (your 10 000 hours of past performance). You can perform the skill well, without thinking too much about it. The process is ingrained in muscle memory, mental short cuts, the process “flows” and can be sometimes effortless, sometimes feel automatic. As you journey through life, your place on this continuum will shift relative to how much you have done, whether you are current in performing this skill, and other factors. Your confidence that you have reached a certain level is continually being challenged by the curveballs that get thrown at you.  

Placing an intercostal chest drain (ICD) for drainage of air / fluid within the chest cavity is a distinct medical skill. It requires good judgement on the indications for the procedure, knowledge of chest anatomy, and understanding of the limitations and complications of the procedure. Based on current training and experience, I would say I sit at the “conscious competence” level of doing this. I am not the fastest or slickest, nor have I performed it on all ages / types of patients and circumstances imaginable, but I have sufficient experience to know how it should go. 

A young man came in with a vague history of fevers, night sweats, weight loss, cough productive of dirty looking sputum, all of which had been ongoing for some time. A chest Xray showed a large opacification of most of the lower half of his left lung, and USS of the chest showed pockets of fluid. A pleuritic tap drained 10ml of thick yellow pus from his chest, which was sent for culture, but no further fluid could be free drained. After discussion with a senior, it was agreed a chest drain should be inserted to better drain the underlying infected fluid. 

I prepared an ICD, the patient was in resus and sedated, and I dissected through the chest wall with ease – he was a slim patient with easy to find rib spaces. The distinct “pop” as the forceps entered the pleural space, was accompanied by a little bleeding, and I placed a gloved finger into the space to sweep. No pus or fluid drained from the hole, and as I swept inferiorly my finger touched something soft, which was pulsating regularly. I froze. Looking at the blood from the wound, which I had assumed to be from a small vessel. Was this lung? Why was it pulsatile? My god is this the mediastinum?! I was terrified I had or was about to puncture the mediastinum and kill this man by accidentally lancing his beating heart. I ran through the process in my mind, I had done everything correctly, the xray showed no mediastinal shift of note, the drain site was still within the “anatomical safe zone”. I stared at my patient, who was well sedated. He was just sedated right?! Yes still breathing. I glance at his monitors – his blood pressure isn’t crashing, everything looks normal still. I called over to my registrar, and she sweeps her finger. She also looks puzzled when meeting the mass within the chest. It is impossible to move it, it feels like solid tissue. She attempts to place the ICD, but is not happy she can get it to pass, so calls the consultant.

He takes a look at the xray, and questions whether this was an effusion as we had first thought. He now takes over and places the drain, which drains no fluid, but does drain air from the iatrogenic pneumothorax which has been created by the procedure. It is time to finish our shift, and I leave a little worried and puzzled. The patient is being discussed with the medical team, but I don’t really understand what was going on in his chest. 

The following day my reg excitedly messages me to say the patient had been causing all sorts of problems for the consultants the previous afternoon, she does not elaborate, and as I drive into work I catastrophise that I have negligently caused irreparable harm or worse killed a patient through my blundering chest drain. My heart is beating faster than it should as we slowly walk into the hospital, I find the reg.  

The patient had been taken for a CT thorax, which was initially viewed by the medical team who then took the emergency consultants to task for placing a chest tube in what they thought looked like a hydatid cyst. The emergency team were relieved when shortly afterwards the CT report confirmed it was actually a loculated empyema after all, and drainage needed to be placed more inferiorly to access the fluid. The fibrous mass we could all feel was a wall of the locule of pus, which has become so established it was tethered to the chest and inpenetrable with a finger. One of the consultants successfully placed a working drain, and 2 days later I greeted the patient as he was strolling around the hospital, his ICD freely draining what looked like strawberry milkshake. He smiled at me and said he felt a lot better.