The course of critical illness

One of the most useful “big picture” lessons in critical care lies in understanding what happens to a person when they become very sick.

The details depend on their specific disease, and learning those particulars is the goal of studying this medical specialty. But details aside, patients will—almost without exception—follow a common general course.

A layperson tends to have a warped expectation of that pathway. If the patient was previously well, and was suddenly struck down by trauma or precipitous medical illness, they think that recovery will be as rapid as the deterioration. The walk into the woods will equal the walk out. They assume things that happen quickly get better quickly.

Like this:

The Naive View: Normal function is interrupted by sudden illness. If the patient survives the acute period, return to normal function is rapid.

Occasionally, this sort of thing does happen, when the patient is young and healthy and we do our job very well—but it is not typical. Much more often, the course of critical illness looks like this:

The Reality: If critical illness is survived, a long subacute period of gradual healing, deescalation, and rehabilitation follows, punctuated by complications and setbacks. The final outcome may not be a full return to baseline wellness.

This is a more realistic picture of critical illness. In the initial period, you become very sick; if we are unable to arrest this freefall, you die. If you survive, you then begin a long, slow journey back toward normal. During this period, you grapple with intermittent setbacks—a pneumonia, a DVT, an iatrogenic complication—each of which recapitulates the same process in miniature, with some risk of death and (if survived) a longer period of healing.

If recovery is successful, the eventual outcome may be a return to normal function. However, in many cases, full recovery is not achieved, and the patient’s new baseline (not expected to further improve) is a life less well and with poorer function than before they became sick.

All of this is further complicated for the many patients with a baseline chronic illness of which this is simply the latest episode. Properly placing the current admission into that context can completely change your understanding of the problem. (For more on this, check out this excellent talk by Ashley Shreves on the meta-course of different chronic disease states.)

What this means for patients

Patients and their loved ones usually do not understand this process.

Explaining it to them upfront can therefore be helpful. Other than the overall shape of the curve, with its long tail and frequent setbacks (“two steps forward, one step back” is the nature of the game), there is also the simple matter of its duration. People do not realize that an injury which took a fraction of a second to acquire may take weeks, months, or years to heal. People do not understand that even when a patient is effectively resuscitated and does very well in the acute period, brushing death’s door and being intubated, undergoing surgery, experiencing heavy sedation, and passing the rest of the ICU gauntlet may still require weeks to “get over.” Certainly, they do not understand the post-ICU syndrome, whereby even patients who have been discharged home may still suffer years of physical disability (inability to climb their own stairs, clothe and bathe themselves, and perform other ADLs), cognitive disability (inability to concentrate, remember simple tasks and concepts, and work in their prior job), and emotional changes such as PTSD.

Painting this general picture early for everyone involved creates the realistic expectation of a marathon ahead, not a sprint. It makes it clear that there will be setbacks, and they are part and parcel of the process. It also makes it clear to family and friends that they will need to pace themselves. Remaining at the bedside 24 hours a day, going without food or a shower, depleting themselves with worry and emotion as if every moment were the season finale in this drama—this game will last too long for that, and they need to behave accordingly. They should settle in for the long haul, so that a month from now they’ll still be able to contribute, rather than burning out early.

Finally, it makes it clear that when the patient is still languishing in the ICU weeks after admission, has been reintubated twice and developed a line infection, and in general seems to be making little progress, this is not necessarily due to poor care or a failure on anybody’s part. It’s just what ICU care looks like. Two steps forward, one step back.

What this means for you

Mastering the first part of the curve—the acute portion—often dominates critical care training, discussion, and attention. This is the resuscitation.

Resuscitation usually involves giving medications, initiating treatments, performing procedures, and doing abnormal things to the patient in the belief that it will help them survive the worst of the disease. These include:

  • Giving fluids (to combat volume loss and inflammation)
  • Giving pressors (to support blood pressure)
  • Placing lines (for reliable access and monitoring)
  • Placing urinary catheters (for strict input/output measurements)
  • Placing chest tubes, drains, intracranial bolts, and other devices
  • Intubation (to protect the airway or for respiratory support)
  • Starting antibiotics (for real or presumed infection)
  • Giving IV sedatives and analgesics (for comfort and safety)
  • Surgical procedures (for source control, repair of trauma, or other indications)

If you fail to get ahead of the disease, the patient does not survive resuscitation.

If you do, you enter the latter part, sometimes called deresuscitation. During this, the “long tail” of deescalating ICU care, we begin to wean, discontinue, and take away. In acknowledgement of the fact that everything we do to a patient has downsides, with each day we look at what’s no longer necessary and start to pare it down. This includes:

  • Getting rid of all the fluid we gave (by diuresis, or even hemodialysis)
  • Weaning and discontinuing pressors, sedatives, and other medications
  • Extubation
  • Taking out central lines (in favor of normal peripheral IVs), arterial lines (in favor of non-invasive blood pressure monitoring), Foley catheters, chest tubes, and other devices
  • Narrowing broad-spectrum antibiotics to a tailored regimen according to culture data, and eventually discontinuing them altogether
  • Starting enteral feeds (i.e. tube feeding), then eventually PO, moving towards a normal diet
  • Discontinuing medications that are no longer necessary, and converting those that still are from IV to PO
  • Restarting home medications
  • Starting therapy (physical therapy, occupational therapy, speech therapy), especially mobilization: sitting up at the edge of the bed, getting out of bed to a chair, ambulating in the halls, etc.
  • Getting out of the ICU, and eventually out of the hospital.

This is important stuff, but is often not emphasized. We like to talk about the glamor of resuscitation, cracking chests and placing tubes; nobody swoons over discontinuing an antibiotic or ordering PT.

But in many ways, this stage is more challenging. There’s no cognitive barrier to aggressively managing a patient in extremis; it’s the obvious thing to do. However, when the time comes to ask whether you still need an arterial line or whether it can come out, deescalation can seem fraught with risk—what if the patient takes a bad turn?—whereas continuing a treatment seems easy. Heck, leave it one more day. It takes experience and mental fortitude to understand that doing too much can be as bad as doing too little; that all of our aggressive treatments have risks and complications; and that deescalation is essential to getting patients back to normal.

The more iatrogenic complications you’ve seen, the easier this gets. You will not become motivated to restart a home beta blocker until you’ve seen patients bounce back from the floor with rapid A-fib, and you will not see the need to remove central lines until you’ve experienced a bad line infection. Eventually, when you look at the orders on a stable patient, you should see a list of opportunities to get rid of things, and removing each one should feel like a victory. You are restoring them to normality. People don’t walk around forever on antibiotics, or with Foley catheters. Get rid of them.

Occasionally, you’ll have to restart something. (Two steps forward. One step back.) Setbacks happen. That doesn’t mean you shouldn’t try. Too much caution results in no progress being made, and patients languishing in the ICU forever.