The MICU patient

Lesson Outline

What is the MICU?

• A grab bag, "ICU of exclusion" - everything that doesn't go elsewhere, similar to internal medicine or general surgery

• Eg surgical might patients go to SICU, neuro patients go to SICU, but if they're none of these, they go to MICU. If they developed a "pneumonia ICU," all those patients would leave the MICU.

• Depends on how many specialty units you have - larger/more academic centers have more . If you don't have a CCU, your cardiac patients will be in MICU, for instance

• What kind of patient other specialty units want to accept tends to depend on local culture and bed availability/volume - eg some SICUs want to take pancreatitis patients (even if non-surgical), some neuro units don't want to see routine non-operative intracranial hemorrhages because they don't have room for it, etc. Generally, if nobody else wants a type of patient, it's the MICU's.

• In smallest centers, there is only one ICU which takes it all.

The MICU patient

• A majority of MICU patients are elderly patients with chronic illnesses. This means:

• Usually complex

• Usually many additional/contributing comorbidities, not directly part of the reason for admission, but still complicating care

• In the majority of cases, the presenting problem is not an isolated acute problem, but an acute exacerbation of a chronic process.

• Usually an incurable organ failure (COPD, CHF, CKD, diabetes, liver failure) which is otherwise relatively stable/compensated at baseline

• The chronic disease is prone to acute decompensations/exacerbations/flare-ups leading to instability, causing ICU admission

• Common causes for exacerbation: med issues (non-adherence, lack of access), infection (local or systemic), other acute disease, progression of underlying disease

• Even when a problem seems truly acute in the MICU, usually it's caused indirectly by a background of chronic frailty, aging, degenerative diseases, psychiatric factors, etc.

• So most of medical critical care involves:

• Stabilizing the acute problem

• Note that patients with acute decompensations of chronic organ failures can be extremely sick, yet have a relatively good prognosis - they are fundamentally recoverable problems (otherwise they would not lead to chronic disease). But they can still kill if not treated promptly, and the end result after recovery is usually a little worse baseline than they started.

• Identifying the trigger, if possible

• Infection, etc

• Optimizing the patient to minimize the chance of it happening again

• Largely not an ICU issue, but the highest risk time after an acute flare is right afterwards - they remain tenuous and there are often gaps in the transition back to outpatient care

The general vibe in the MICU

• Diagnostically interesting cases, like all internal medicine

• There are relatively few "medical mysteries" in most other ICU services, as their very admission to a specialty requires a diagnosis of some type

• Therapeutically hit or miss

• The "bang for buck" of care depends on how much acute versus chronic element there is. When the ratio is very high (a truly acute, reversible issue), you can affect outcomes a lot. When it's low, the benefit of even the best critical care is slim. Fundamentally, MICU has a lower ratio than other places like the SICU.

• Need to embrace the care of elderly, chronically ill patients to enjoy the MICU. Palliative care and addressing goals of care plays an important role for most patients.

• Even the best MICU "save" may still result in a patient with a relatively short life expectancy due to other problems.

• Fairly long patient stays, a lot of bouncebacks

• Surgical patients - get better fast, lots of turnaround

• Neuro patients - often very long stays due to trajectory of disease

• Medical falls in between. Many who leave may come back (from floor or home). "Frequent fliers" are common.

• Cognitively rich

• Lots to consider, if you want to

• Internal medicine stereotype: talk about everything, but do nothing

• Most common problems:

• Sepsis: pneumonia (including aspiration) in particular

• Respiratory failure: infectious, CHF, COPD

• Altered mental status: various causes

• DKA, alcohol withdrawal, A-fib with RVR, liver disease may all be more or less common depending on catchment and other units (e.g. some centers may allow reasonable cases of RVR, DKA, alcohol withdrawal, etc onto a stepdown unit

Workflow

• ICU usually primary team

• In surgical ICUs, surgical teams may be primary, or at least exercising heavy involvement in important decisions

• In academic centers, house staffing is common

• Internal medicine or other residents

• APPs may be involved, either woven into those teams as additional staff, or organized into separate teams

• Fellows may be present

• Intensivists often dual-trained in pulmonary and critical care

• May be pure critical care, but fewer of these training programs around

• Intensivists come to critical care from other pathways, but internal medicine to critical care is most common for most MICUs

• Anesthesia, surgery, neurology, others - although some centers may try to put these intensivists in other ICU types

Closing thoughts

• MICU is not for everyone, but is arguably the "oldest" or most fundamental flavor of critical care

• It can be the broadest and require the most general knowledge base

• It can inherently be less fast-paced/exciting/stimulating than some settings

• Every ICU patient has "medical" problems; we all need to have a strong understanding of all aspects of critical care regardless of our setting.