The original French word describing what modern physicians in English call “shock,” was first used by the French surgeon, Henri Francois Le Dran.
It described his observations of what happened to patients who were shot with musket balls. These observations were not limited to blood loss or the delivery of O2, but of the totality of the effects over time.
Shock is my favorite subject in medicine. I read and write a lot about it. I am writing it here because I am getting tired of typing it again and again.
For the last 50 years or so, modern medicine has wrongly simplified and attributed shock to the failure of delivery of O2, by several mechanisms which were given names like “distributive,” “hemorrhagic,” “septic” etc…
Shock is multi-factorial, concurrent processes in the body, most notably triggered by a combination of the failure of delivery of o2, inflammation, and kinin cascades. Shock is not so much a disease as it is a point in time of an underlying disease process.
The chronology of this process is compensation, decompensation, multiple organ dysfunction, multiple organ failure, and finally death.
What makes shock pathological is that in its decompensated phase, instead of helping to maintain homeostasis, it instead inhibits it.
It is important to understand that shock is a systemic process, it is not restricted to a specific area or system. In fairness, depending on the severity and medical treatment, the obvious clinical effects may not always be significant, however, they still exist, and become more important as both the length of time the patient is in shock as well as the severity of it progresses. It would take me no less than a novel to type out every systemic interaction shock has, but I will give a few examples here. In addition the the obvious ones, like inflammation or bleeding, there are changes in protein composition in brain cells and function, particularly in the limbic area, there are changes in metabolism from an anabolic state to a catabolic state. From sex hormones to all of the blood pressure and fluid retention pathways are altered in some way.
Shock may be acute or chronic.
Acute shock is very easy to see clinically, the signs and symptoms, as well as biochemical findings are well described other places so I will not repeat them here. I don’t know any providers who cannot at least recite many of these. We see it often in every condition from dehydration to massive hemorrhage, chances are if you are reading this, you have experienced being in shock at some point in your life (pretty much unless you live in a bubble in a safe space).
Chronic shock, is seen, but rarely described as such, instead being given the moniker of “early stage” or “compensation” for an underlying disease process. A good example of this is heart failure. Heart failure is a response to stressed myocardial cells. In order to maintain cardiac output, we see compensatory mechanisms like faster heart rate, narrowing of blood pulse pressures, early stage hypertension, late stage hypotension. We see late stage cardio-renal disease, which is just the chronic form of AKI in acute shock, by the same mechanisms. Any person who is suffering from a chronic disease is, for all intents and purposes, at a baseline of compensated shock. As we know, this takes a toll on the body and over time, the victim transitions from well compensated to decompensated, with the entire purpose of medical care and support to slow or reverse this process.
The treatment of shock comes in 2 stages, regardless of whether or not it is acute or chronic. The first stage is organ support. Which is probably more accurately described as “system” or “organism” support. This support is designed to reduce stress on other organs and systems subsequent to the underlying cause. This is best demonstrated in general anesthesia, where shock is induced in the patient, and numerous monitoring and organ support techniques are then applied to maintain the level of shock, preventing both decompensation>MODS>MOF>death, as well as normalization secondary to compensation, aka the patient waking up with full function and awareness.
The second stage of the treatment of shock is the repair or regeneration of the underlying cause which incites it. This may take the form of restoring blood flow and subsequently O2 delivery to an infarcted myocardium. It may be the resolution of an infectious process, surgical reconstruction to maintain homeostasis in some way, such as fixation or amputation. It may be any number of medical treatments, such as mechanical ventilation or antibiotics.
I think the most common mistakes for providers attempting to treat shock patients is the oversimplification of what shock is and the lack of awareness that system support is entirely different from treatment of the underlying cause/cure.
This misperception that shock is a disease process, rather than a point in diseases process drives the over-simplification of both its teaching as well as attempts at treatment. This is seen by patients progressing in decompensation despite various established and long-standing treatments expertly applied as well as numerous conflicting study findings of various treatment modalities when applied to shock patients universally, rather than individually.
Because shock affects every system in the body and the entire purpose of all the body’s systems is to maintain homeostasis, the complexity of this I attempt to describe as a set of scales with multiple parts to balance. Applying any treatment to one part of the scale affects every other one. Contrary to more antiquated thought of “doing as much of nothing as possible”, which in a shock state seems rather negligent, and certainly not expert to me…”Do nothing and if the patient lives take credit, if they die deny responsibility”, I profess that to successfully treat a shock patient, precision of treatment, applied at the proper time is the key to success.
Good examples of this range from treatments such as blood transfusion in hemorrhage to steroids in sepsis, and even catecholamine uses in cardiac arrest. There are no shortages of studies which are inconclusive or conflicting. The 2 things missing from many of these studies however are: 1. the differentiation of patient cohorts, with many being lumped into overly broad categories in order to reach statistical significance and power and 2. The utter lack of account for timing of the studied treatment. If you are treating an illness that changes over time, certainly when you apply that treatment is significant in any observation?
Another aspect of shock treatment that I would say is oversimplified is the focus on fixed time points rather than a continuum. Patients don’t just suddenly go from compensated to decompensated to MODS, MOF, death. There is a steady progression from initial stress response, increased physiologic response, early, middle, and finally late decompensation and then through the MODS>MOF> death pathway.
It is also why I am so opposed to the term “irreversible shock”. When exactly is that? Nobody knows until the post-game wrap up. Irreversible shock is MODS>MOF. A time when organ support and medical treatment can no longer maintain homeostasis. It is at this point in time where biochemical and molecular cascades have progressed passed modern medical intervention.
This leads right in to the importance of early recognition and treatment of shock. Since modern medicine lacks the ability to stop or reverse these biochemical cascades, it becomes more important to recognize and treat patient conditions before they reach that stage. In the modern era, shock is the final stage in a disease process where it is possible to intervene. Hopefully one day that will change, but it will not be in the next few years (probably not the next decade, but I remain hopeful).
If you want to be expert, or even successful at treating shock, you have to really understand it, not just some oversimplified explanation of failure of delivery of DO2. You have to see it as a progression over time, not as fixed points. You must understand and recognize the difference between organ support and curative treatment. Finally, you must be accurate and precise in both the type of treatment as well as the timing of them in order not to unbalance one or more scales attempting to balance 1 or 2 others.
The understanding of shock is a river both a mile deep and a mile wide. I would go as far as to say it could be a medical as well as academic research discipline all to itself. Shock is completely unsuited to protocolized medicine. Treating it is an art, which requires masterful understanding of basic science, before clinical science can even be applied. Especially because of the different physiology and compensatory responses in different age groups.
I hope this has given you at least an insight as to how complex and underestimated shock really is.