Managing Psychiatric Consultation Liaison

Managing Psychiatric Consultation-Liaison

Structures consultation-liaison (C-L) psychiatry assessments for medical-surgical inpatients with delirium, capacity evaluation, behavioral management, and psychosomatic concerns using the Academy of Consultation-Liaison Psychiatry (ACLP) standards.

Why This Skill Exists

Consultation-liaison psychiatry operates at the interface of medicine and psychiatry, providing psychiatric assessment and management for patients on medical and surgical services. Approximately 5-10% of hospitalized medical patients receive psychiatric consultation, with the most common referral reasons being delirium (30-40% of consults), capacity evaluation (15-20%), depression/suicidality (15%), agitation/behavioral disturbance (10%), and substance use management (10%). C-L psychiatry requires a unique skill set: the ability to diagnose psychiatric illness in the context of medical complexity, manage psychotropic medications in patients with organ dysfunction and polypharmacy, and communicate effectively with non-psychiatric medical teams.

Poor C-L documentation leads to fragmented care, medication errors (drug interactions between psychotropics and medical medications), missed diagnoses (especially delirium attributed to psychiatric illness), and prolonged hospital stays. The consultation note must clearly answer the referral question, provide actionable recommendations, and educate the referring team — all within the constraints of an efficient inpatient workflow.

Checkpoint A: Pre-Draft Intake (Mandatory)

1. What is the specific consultation question? (delirium evaluation, capacity assessment, depression management, agitation management, substance withdrawal, medication adjustment, coping with medical illness, suicidality assessment, discharge planning barrier) — default: clarify with requesting team
2. What is the patient's primary medical diagnosis and current treatment? — default: review chart before seeing patient
3. What is the patient's current mental status? (alert, confused, sedated, intubated, non-verbal) — default: assess
4. Is the patient medically stable? (ICU vs. floor, on vasopressors, acute organ failure) — default: review current status
5. What medications is the patient currently receiving? (focus on psychoactive medications: opioids, benzodiazepines, steroids, anticholinergics, antibiotics with CNS effects) — default: complete medication review
6. Is there a known psychiatric history? — default: obtain from patient, family, and prior records
7. What is the urgency? (emergent — safety concern, urgent — same-day, routine — 24-48 hours) — default: triage
8. Who is the requesting provider and what is the best method for communicating recommendations? — default: identify

Documents to Request

• Complete medical chart (H&P, daily progress notes, surgical/procedure notes)
• Current medication administration record (MAR)
• Nursing flow sheets (vital signs trends, neurological checks, restraint documentation)
• Laboratory results: CBC, CMP, hepatic panel, ammonia, TSH, B12, blood cultures, UA/UCx, drug levels, blood alcohol, UDS
• Brain imaging (CT or MRI if available)
• ECG (baseline QTc)
• Prior psychiatric records and medication history
• Advance directives and healthcare proxy documentation
• Social work assessment
• Occupational/physical therapy assessment for functional status

Step 1: Chart Review and Pre-Consultation Preparation

Before seeing the patient, complete a thorough chart review:

Medical context:

• Primary diagnosis and reason for hospitalization
• Surgical procedures performed and dates
• Hospital course to date (complications, code events, ICU stays)
• Current medical medications with focus on CNS-active agents:
  • Opioids (fentanyl, morphine, hydromorphone — delirium risk, respiratory depression)
  • Benzodiazepines (midazolam, lorazepam — delirium risk, paradoxical agitation in elderly)
  • Anticholinergics (scopolamine, atropine, promethazine — delirium risk)
  • Steroids (dexamethasone, prednisone — mood changes, psychosis, mania, insomnia)
  • Antibiotics with CNS effects (fluoroquinolones — seizures, psychosis; metronidazole — neuropathy)
  • Immunotherapy/chemotherapy agents (interferon — depression; checkpoint inhibitors — various)
  • Anti-epileptics (levetiracetam — behavioral changes, aggression)

Relevant labs and imaging:

• Metabolic panel (electrolytes, glucose, renal function, hepatic function)
• Ammonia (hepatic encephalopathy)
• TSH (thyroid dysfunction)
• B12 and folate
• Blood cultures, UA (infection driving delirium)
• UDS and blood alcohol
• Brain imaging if altered mental status
• QTc from ECG (essential before prescribing antipsychotics, SSRIs, or methadone)

Step 2: Bedside Assessment

Clarify the consultation question with the referring provider before or during the assessment. Common discrepancy: team requests "psych eval" when the actual question is "is this delirium or dementia?" or "can this patient refuse surgery?"

Psychiatric interview in the medical setting:

• Introduce yourself as a psychiatrist/psychiatric consultant — many medical patients are surprised or offended by a psychiatric consultation they did not request. Handle with sensitivity.
• Chief complaint (in the patient's words, if able to communicate)
• History of present psychiatric symptoms, contextualized within the medical hospitalization
• Past psychiatric history (prior diagnoses, hospitalizations, medication trials, suicide attempts, substance use)
• Mental status examination (complete, with attention to delirium features)
• Cognitive assessment: Orientation, attention (digit span, months backward), CAM if delirium suspected

Delirium assessment (most common C-L referral question):

Use the Confusion Assessment Method (CAM):

1. Acute onset and fluctuating course (ask nursing about changes over the past 24 hours)
2. Inattention (digit span, serial 7s, months backward — the most sensitive feature)
3. Disorganized thinking (illogical, tangential, incoherent responses)
4. Altered level of consciousness (hyperalert, lethargic, stuporous) Positive CAM: Features 1 + 2 AND (3 OR 4)

Delirium subtypes:

• Hyperactive: Agitation, restlessness, pulling at lines, hallucinations (easiest to diagnose)
• Hypoactive: Lethargy, withdrawal, reduced alertness, apathy (most commonly missed — frequently misdiagnosed as depression)
• Mixed: Alternating hyperactive and hypoactive features

Step 3: Differential Diagnosis in the Medical Setting

C-L psychiatry requires distinguishing between medical and psychiatric causes of behavioral change:

Delirium vs. Dementia vs. Psychiatric illness:

Common medical causes of psychiatric symptoms:

• Delirium: Infection (UTI #1 in elderly), medication toxicity, metabolic derangement, post-surgical, alcohol/benzodiazepine withdrawal, hepatic/renal encephalopathy, hypoxia, stroke, seizure (post-ictal)
• Depression: Hypothyroidism, pancreatic cancer, stroke (left frontal), Parkinson's disease, medications (beta-blockers, interferon, steroids)
• Mania: Steroids, stimulants, thyroid hormones, stroke (right hemisphere), autoimmune encephalitis
• Psychosis: Delirium (always rule out first), steroids, dopamine agonists, anticholinergics, autoimmune encephalitis (anti-NMDA receptor), temporal lobe seizures
• Anxiety: Hyperthyroidism, pheochromocytoma, pulmonary embolism, medication withdrawal, pain, hypoxia
• Catatonia: Medical etiologies (autoimmune, metabolic, medication-induced) — always check CK, perform benzodiazepine challenge

Step 4: Recommendations and Medication Management

Structure recommendations clearly for the non-psychiatric medical team:

Consultation note format:

1. Identification and reason for consultation (one sentence)
2. Summary of relevant history (focused on the consultation question)
3. Mental status examination (complete)
4. Differential diagnosis (ranked by probability)
5. Assessment (answering the consultation question directly)
6. Recommendations (numbered, specific, actionable)

Medication considerations for medically ill patients:

• Renal impairment: Avoid lithium. Reduce doses of gabapentin, pregabalin. Lorazepam and oxazepam are preferred benzodiazepines (no active metabolites). Adjust doses of renally cleared medications.
• Hepatic impairment: Avoid valproate, nefazodone. Use lorazepam or oxazepam (glucuronidation, less affected by hepatic CYP dysfunction). Reduce doses of most SSRIs and antipsychotics.
• Cardiac disease / QTc prolongation: Avoid citalopram >20mg, ziprasidone, IV haloperidol, thioridazine, tricyclics. Monitor QTc. Safer options: sertraline, mirtazapine (minimal cardiac effects).
• Seizure risk: Avoid bupropion, clozapine, chlorpromazine (lower seizure threshold). Safer: SSRIs, valproate.
• Post-surgical patients: Pain management coordination (avoid excess opioids that cause delirium; avoid SSRIs with antiplatelet activity pre/peri-operatively per surgical team preference).
• Drug interactions: Use Lexicomp or Epocrates to check every psychotropic against the current medication list.

Delirium management recommendations:

1. Treat the underlying cause (antibiotics for infection, correct metabolic derangement, remove offending medication)
2. Non-pharmacological interventions: Reorientation (clock, calendar, family photos), sleep hygiene (minimize overnight vitals/labs, reduce noise, dim lights at night), early mobilization, correct sensory deficits (glasses, hearing aids), maintain hydration and nutrition
3. Pharmacological (for severe agitation threatening safety or interfering with essential medical treatment): Low-dose haloperidol 0.5-2mg PO/IM (monitor QTc), or quetiapine 12.5-50mg PO (preferred in Parkinson's/Lewy body). Avoid benzodiazepines for delirium (worsen confusion) EXCEPT in alcohol/benzodiazepine withdrawal delirium.

Step 5: Communication, Follow-Up, and Disposition

Effective C-L communication:

• Speak directly with the requesting provider (curbside or call) — do not rely solely on the written note
• Provide a concise verbal summary answering the consultation question
• Offer clear, prioritized recommendations (number them)
• Indicate which recommendations are urgent vs. can wait
• State clearly whether you will follow the patient or this is a one-time consultation
• Document the verbal communication in the note

Follow-up criteria:

• Follow daily for: active delirium, ongoing capacity questions, active suicidality, medication titration, complex behavioral management
• Follow every 2-3 days for: stable medication management, depression not requiring daily adjustment
• Sign off when: consultation question is fully answered, patient is psychiatrically stable, discharge is imminent and outpatient follow-up arranged

Discharge planning:

• Ensure psychotropic medications started in-hospital are continued or appropriately tapered at discharge
• Arrange outpatient psychiatric follow-up before discharge
• Communicate medication changes to outpatient providers
• Provide patient/family psychoeducation about new diagnoses (especially delirium education — families need to understand that delirium is reversible but recovery may take weeks)
• Document discharge psychiatric assessment and recommendations

Checkpoint B: Post-Draft Alignment (Mandatory)

1. Is the specific consultation question clearly stated and directly answered?
2. Is delirium assessed and ruled out for any acute behavioral change?
3. Are medication recommendations adjusted for the patient's medical conditions (renal, hepatic, cardiac)?
4. Are recommendations numbered, specific, and actionable for the non-psychiatric team?
5. Is the follow-up plan documented (daily follow, periodic, or sign-off)?

Quality Audit

• Consultation question clarified with requesting provider
• Chart review completed before bedside assessment
• Complete medication review with focus on CNS-active agents
• Relevant labs reviewed (metabolic panel, ammonia, TSH, UDS, QTc)
• Full mental status examination documented
• Delirium screen (CAM) performed for any altered mental status
• Differential diagnosis addresses medical vs. psychiatric etiologies
• Recommendations are numbered, specific, and actionable
• Drug-drug interactions checked for recommended psychotropics
• Dosing adjusted for organ impairment (renal, hepatic)
• QTc checked before recommending QTc-prolonging psychotropics
• Communication with requesting provider documented
• Follow-up plan stated (daily, periodic, or sign-off)
• Discharge psychiatric recommendations documented

Guidelines

1. Always rule out delirium before diagnosing a new psychiatric disorder in a hospitalized patient — the most common C-L mistake is misdiagnosing hypoactive delirium as depression.
2. Speak directly with the requesting team — the written consultation note is necessary but not sufficient. A brief verbal summary dramatically improves recommendation adherence.
3. Adjust all psychotropic doses for organ function — hepatic and renal impairment change drug metabolism, and the medically ill tolerate lower doses than outpatient psychiatric patients.
4. Check QTc before prescribing any antipsychotic, SSRI (especially citalopram/escitalopram), or methadone in the medical setting — critically ill patients are at higher baseline risk for QTc prolongation.
5. Do not use benzodiazepines for delirium management (except alcohol/benzodiazepine withdrawal delirium) — benzodiazepines worsen delirium by further impairing arousal and cognition.
6. Number your recommendations and keep them to 3-5 actionable items — medical teams are more likely to follow concise, prioritized recommendations than lengthy narratives.
7. For capacity evaluations in the medical setting, assess and address reversible factors (pain, delirium, sedation) before concluding that the patient lacks capacity — capacity is often recoverable.
8. Document whether the consultation is one-time or ongoing — failure to clarify follow-up expectations leads to gaps in care.