Workup for 30F Psychiatric Patient with Psychosis, Substance Use History, Tachycardia and Dizziness
A comprehensive medical evaluation is essential for this patient presenting with tachycardia and dizziness given her psychiatric admission and substance use history, as these symptoms likely represent an underlying medical condition requiring immediate attention rather than psychiatric manifestations.
Initial Medical Assessment
- Vital signs: Complete set including temperature, heart rate, blood pressure (lying and standing), respiratory rate, and oxygen saturation 1
- Focused physical examination: Particular attention to cardiovascular, neurological, and respiratory systems to identify potential causes of tachycardia and dizziness 1
- Mental status examination: Assess orientation, cognition, and presence of psychotic symptoms 1
- Hydration status: Evaluate for signs of dehydration which is common after substance use and can cause tachycardia 1
Laboratory Workup
- Basic metabolic panel: To assess for electrolyte abnormalities, renal function, and acid-base disturbances that may cause tachycardia and dizziness 1
- Complete blood count: To evaluate for anemia or infection that could contribute to tachycardia 1
- Toxicology screen: Comprehensive urine and serum drug testing to identify substances that may be causing or exacerbating symptoms 2, 3
- Thyroid function tests: To rule out hyperthyroidism which can present with tachycardia 1
- Cardiac enzymes: To rule out cardiac injury if clinically indicated 1
Cardiac Evaluation
- 12-lead ECG: Essential to evaluate for arrhythmias, QT prolongation, and other cardiac abnormalities 1
- Consider continuous cardiac monitoring: Especially if tachycardia is persistent or severe 1
Neuroimaging
- Consider head CT/MRI: If new-onset psychosis with no prior psychiatric history, to rule out intracranial processes 4
- Tailor imaging protocols: Use shorter scan times or motion-reducing sequences if patient is agitated 4
Substance-Induced Considerations
- Withdrawal assessment: Evaluate for signs of alcohol or sedative withdrawal which can cause tachycardia and autonomic instability 2, 5
- Stimulant toxicity evaluation: Assess for signs of cocaine, amphetamine, or other stimulant intoxication 3, 5
- Timeline correlation: Document relationship between substance use and onset of psychotic symptoms 6
Management Approach
- Treat underlying medical causes first: Address tachycardia and dizziness before focusing exclusively on psychiatric symptoms 1
- Consider benzodiazepines: For management of agitation and potential withdrawal symptoms if indicated 1
- Fluid resuscitation: If signs of dehydration are present 1
- Antipsychotic medications: Consider only after medical causes have been ruled out; use atypical antipsychotics when possible 1
Important Considerations
- Diagnostic reassessment: Up to 46% of patients with psychiatric symptoms have medical illnesses directly causing or exacerbating their psychiatric presentation 1
- Avoid premature attribution: Do not assume psychotic symptoms are due to primary psychiatric disorder without ruling out substance-induced or medical causes 6
- Monitor for conversion: Substance-induced psychosis can convert to schizophrenia or bipolar disorder in up to one-third of cases 2
Follow-up Planning
- Close monitoring: Continue cardiac and vital sign monitoring until tachycardia resolves 1
- Substance use treatment: Include substance use disorder treatment in discharge planning 2, 3
- Psychiatric follow-up: Ensure appropriate psychiatric follow-up after medical stabilization 7
Remember that patients with substance use histories presenting with new physical symptoms require thorough medical evaluation before attributing symptoms to psychiatric causes 1, 6.