Which laboratory tests are needed to medically clear psychiatric patients?

by
John F. Madden, MD, FAAEM
Clinical Assistant Professor of Surgery (EM) Jefferson Medical College
Professor of Medicine St. George's University School of Medicine
Christiana Care Health System
Newark, Delaware

The medical evaluation of psychiatric patients has been a subject of contention among emergency physicians and mental health practitioners for decades. Emergency physicians don't want to send a hypoglycemic patient or one with meningitis to a psychiatric facility, but I believe those days are behind us. But what exactly is "medical clearance"? Are we expected to rule out any and all medical illnesses? So, what then is an appropriate evaluation? Well, that depends on the patients themselves.

A fifty year old male without prior behavioral problems or mental illness who presents with a sudden behavioral change deserves a much more aggressive medical evaluation than a known schizophrenic who stopped taking their medications several days ago and is brought in by the police for abnormal behavior at the local convenience store. The caveat of course is that psychiatric patients may also have a medical illness, but a diligent medical examination hopefully will reveal any such medical problems. For instance, evidence of head trauma, a fever, unexplained tachycardia or history of diabetes all call for a thorough medical evaluation before any behavioral change is attributed to the underlying psychiatric illness. Occasionally, a patient with altered mental behavior will refuse evaluation after being brought by law enforcement. They might refuse any attempt to take vital signs or laboratory evaluation. While they might be in the process of being committed to a psychiatric facility, depending on state law, the patient might still maintain certain rights that prohibit us from doing what the patient is refusing. However, much can be garnered from simply observing the patient. Are they diaphoretic, dyspneic or are their clothes bloody? As always, doing what is best for the patient is the most reasonable route and, sometimes after attempting to contact a family member, or discussing the patient with another physician, we have to forcefully sedate the patient in order to obtain a thorough evaluation. Many of us have been denied droperidol in our formulary since the dreaded "black box" warning was added, but the combination of haloperidol and lorazepam IM work quite well when used as part of appropriate emergency sedative protocols with adequately trained personnel to administer the "dart." The only problem with this maneuver is potential oversedation and the inability of mental health personnel to evaluate the patient until they awaken.

Once a general history and physical exam are accomplished, we are at a stage where we usually consider ordering lab studies. If any are indicated at all, depends on the patient as mentioned earlier. The mnemonic AEIOU-TIPS is a simple way to remember life-threatening conditions that may cause altered mental status (see table 1). So are we to send a CBC, chemistry panel, calcium, magnesium, alcohol level, urine toxicology and urinalysis on every patient? Do they also need a brain CT and lumbar puncture to rule out meningitis?

Table 1 A Alcohol/drugs, acidosis E Electrolyte abnormalities, encephalopathy I Infection (CNS, sepsis) O Low Oxygen (hypoxia) U Uremia T Trauma I Intracerebral bleeding P Poisoning S Seizures, stroke, low glucose

Many of these patients also are involved with substance abuse and so many mental health personnel routinely request an alcohol and drug screen without seeing the patient and there being no clinical reason to do the test. My own ED has been using a format (Table 2.) that we came up with without any scientific basis after discussing and discussing again the expected evaluation of patients being committed to the local state psychiatric facility. This was a consensus opinion that involved input from emergency physicians from all around our (quite small) state and the psychiatrists, psychologists and social workers at the receiving facility. It took a bit of negotiating and after three years, they attempted to change it, but were unable to present any legitimate bad outcomes from the period we were using this agreement. We have been using it for over seven years and it has served us well.

Table 2 Medical Check List for Patients Referred to Psychiatric Facility A) Patient with known psychiatric illness: > if patient appears intoxicated, ETOH determination if clinically indicated > urine tox screen if clinically indicated (document if patient refuses or is unable) > if on anticonvulsant meds, send drug level > if patient febrile, evaluate source: --CBC prn --CXR prn --appropriate cultures --discharge patient with appropriate follow up recommendations B) Patient without known psychiatric illness: > complete physical examination > ETOH determination and urine toxicology if clinically indicated > CBC, Chem 7, Calcium > CK if UA is positive for blood without rbc's on microscopic exam > Urinalysis > Brain CT scan: hold if no evidence of head trauma or if ETOH or urine toxicology were positive and patient is improving, i.e., altered mental status is improving > consider lumbar puncture if the patient is febrile

So, to answer the question as to what lab studies are necessary to clear a patient before going to a psychiatric facility, it may involve a urine toxicology screen for the benefit of the mental health personnel who like to know if the patient has been abusing legal substances, sometimes a urine pregnancy test if there are other signs of pregnancy, and, occasionally, it is no tests at all. As to an alcohol level, facilities in our area feel that if an alcohol level is above 200, the patient cannot be evaluated. Our agreement has been that
if the patient can "walk and talk" they can be evaluated regardless of their BAC. This may mean we keep some patients who have alcohol levels below 200 but who can't walk and talk, but we frequently will not even obtain a BAC. As experienced clinicians, many of us have learned to recognize an intoxicated individual without the benefit of a lab test and we have so convinced our psychiatric colleagues.

The best article I have seen on this topic is the following:

Karas S: Behavioral Emergencies: Differentiating Medical From Psychiatric Disease. Emergency Medicine Practice, March 2002, Volume 4, Number 3. It is evidence based, offers a thorough overview of this topic and is highly recommended.

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