7.2 Mental, Substance Use, Injuries/Toxicology, and HIV-Related Conditions

7.2 Mental, Substance Use, Injuries/Toxicology, and HIV-Related Conditions

Quick Answer: Do not treat psychosis, dementia, delirium, and encephalopathy as synonyms. Separate alcohol intoxication from alcohol withdrawal. Classify drug harm as poisoning (improper use), adverse effect (correct drug, correct administration), or underdosing (less than prescribed; never principal). For human immunodeficiency virus (HIV), Z21 is asymptomatic status; B20 is HIV disease and, once an HIV-related illness has occurred, B20 is used on every later encounter. Use DRG Expert to see whether a documented condition is a major related condition in Major Diagnostic Category (MDC) 25. Functional quadriplegia needs a provider statement of complete immobility from frailty or severe disability, not a nursing total-care row and not spinal tetraplegia.

This independent OpenExamPrep section helps inpatient CDI specialists study these other MDC topics for the CCDS exam. It is not an ACDIS product and does not claim ACDIS approval, review, or partnership.

Psychosis is unfinished documentation

Psychosis at the bedside is a family of presentations: schizophrenia and related disorders, bipolar disorder with psychotic features, major depression with psychotic features, substance-induced psychotic disorder, and perceptual disturbance in delirium. A nursing comment that the patient is psychotic is an indicator, not a diagnostic statement. Query for the type and, when substances or a medical cause are in play, the cause. Do not assign unspecified psychosis from a sitter order. Do not convert delirium with hallucinations into a primary psychotic disorder because an MCC looks attractive. The 2026 query standard still requires clinically relevant options, Other, please specify, and no reimbursement language. Yes/no may not introduce a new psychiatric diagnosis.

Dementia versus delirium versus encephalopathy

Dementia is a chronic, usually progressive baseline cognitive disorder (Alzheimer disease, vascular dementia, Lewy body disease, and other specified types). Capture type when the provider states it, and capture with behavioral disturbance only when that disturbance is documented and relevant this stay under Uniform Hospital Discharge Data Set (UHDDS) secondary-diagnosis rules (evaluation, treatment, extra monitoring, or extended length of stay). A copied problem-list line of dementia does not automatically meet UHDDS.

Delirium is an acute, fluctuating disturbance of attention and awareness. Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) scores, a sudden change from baseline, and a precipitant such as infection, hypoxia, or polypharmacy are indicators. Delirium can overlay dementia. That overlap is a query, not a silent swap.

Encephalopathy is a provider neurologic diagnosis of diffuse brain dysfunction. Type and cause matter (metabolic, toxic, hepatic, hypertensive, anoxic). Chapter 4 of this guide treats encephalopathy in depth. The trap in this cluster is using encephalopathy as a prettier word for delirium, or using delirium as a prettier word for dementia, in order to change severity. If the record mixes the terms, query. Do not relabel CAM-ICU-positive delirium as metabolic encephalopathy solely because metabolic encephalopathy can group as an MCC when it is documented, supported, and not inherent to the principal diagnosis.

Original scenario. Mr. L., 84, lives with documented Alzheimer disease. On hospital day two he is CAM-ICU positive, picking at lines, and oriented only to self after hyponatremia to 118 mEq/L. The intern writes worsening dementia. CDI should not upgrade chronic dementia into a new baseline. A nonleading query can ask whether the acute change is delirium, metabolic encephalopathy related to hyponatremia, expected fluctuation of known dementia without a separate acute diagnosis, or Other, please specify.

Alcohol: intoxication is not withdrawal

Alcohol intoxication is the acute effect of recent drinking: slurred speech, ataxia, a measurable ethanol level, and often trauma. Alcohol withdrawal is the syndrome that appears after cessation or reduction: tremor, tachycardia, hypertension, diaphoresis, Clinical Institute Withdrawal Assessment for Alcohol (CIWA) protocol, benzodiazepines, withdrawal seizures, or withdrawal delirium (delirium tremens). The same patient can arrive intoxicated and withdraw on day two. Those are sequential diagnoses, not synonyms. A problem list that says only ETOH is unfinished work.

Thiamine, folate, and a banana bag are nutritional-risk indicators. They do not by themselves establish Wernicke encephalopathy. Query if ophthalmoplegia, ataxia, and confusion are present and the provider has not named the diagnosis. Do not use a yes/no query that plants Wernicke from a vitamin order.

Poisoning versus adverse effect versus underdosing

ICD-10-CM categories T36–T50 are combination codes that include the substance and the intent. Do not code directly from the Table of Drugs and Chemicals; confirm in the Tabular List. No extra Chapter 20 external-cause code is required for these T-codes.

Original scenario. Ms. H. takes warfarin exactly as prescribed. She is admitted with hematemesis and an international normalized ratio of 9.2. This is an adverse effect pattern: the nature of the effect is the bleed, then the T-code for anticoagulant with character 5. It is not a poisoning because the drug was taken correctly. It is not underdosing.

Original scenario. Mr. J. takes extra oxycodone from a leftover bottle plus beer and is found unresponsive; naloxone reverses him. Interaction of a drug with alcohol is classified as poisoning. Intent still has to be documented or queried; do not invent intentional self-harm from a single overdose if the record is silent.

Original scenario. Ms. C. stops her furosemide because she was traveling, then presents in acute heart-failure exacerbation. Underdosing is additional, never principal. The heart-failure exacerbation is the condition that occasioned the admission if that is what the record supports.

HIV: sequencing, Z21 versus B20, and DRG Expert grouping

Provider documentation that the patient is HIV positive or has an HIV-related illness is sufficient; serology is not required to “confirm” the statement. Z21, Asymptomatic human immunodeficiency virus infection status, applies when the record says HIV positive, known HIV, or HIV test positive without symptoms or HIV-related illness. Do not use Z21 if the term AIDS or HIV disease is used, or if the patient is treated for any HIV-related illness. B20, Human immunodeficiency virus disease, is assigned in those situations. Once an HIV-related illness has developed, B20 is assigned on every subsequent encounter; the patient does not return to Z21 or to R75 (inconclusive serology). Antiretroviral medication does not by itself convert Z21 into B20; the Official Guidelines distinguish HIV disease or AIDS on antiretrovirals (B20) from HIV-positive status on antiretrovirals without additional documentation of disease (Z21).

If the patient is admitted for an HIV-related condition, B20 is principal, followed by codes for the related conditions (with a published exception for infection-associated hemolytic-uremic syndrome, which is sequenced before B20). If the patient is admitted for an unrelated condition such as a traumatic injury, the unrelated condition is principal and B20 is secondary. New versus old diagnosis does not change that sequencing logic.

Major related condition is a Medicare Severity Diagnosis Related Group (MS-DRG) grouping concept, not an Official Guidelines synonym for MCC. CMS places HIV cases in MDC 25. The Definitions Manual and DRG Expert (an allowed optional resource on the CCDS exam) list which diagnoses count as HIV with major related condition versus HIV with or without other related condition. Opportunistic infections such as pneumocystosis appear on the major-related lists; many other documented problems do not. Look the condition up. Do not memorize an unpublished relative weight, and do not invent a homemade major-related list. CDI value is making sure the provider has actually diagnosed the related condition that the grouper can see—not dropping pneumocystosis in from a historical CD4 nadir.

Trauma documentation

When injury occasioned the admission, the nature of injury is the principal-diagnosis conversation: site, laterality, open versus closed, displacement when documented, intracranial injury versus concussion, and loss of consciousness if the provider states it. Radiology of a possible occult fracture is an indicator until the provider indicates clinical significance (see section 7.3). Glasgow Coma Scale values are indicators and, when reported, follow Official Guidelines for coma-scale use; do not report unspecified coma for a medically induced or purely sedated state.

Falls and trauma that are not present on admission can intersect the HAC payment-provision category for falls and trauma (fractures, dislocations, intracranial injury, crushing, burns, and other listed injuries). That is the claim-level payment provision. It is not the HAC Reduction Program, and it is not PSI-90 by another name. POA for an injury that occurred before the inpatient order, including in the emergency department, is Y.

Functional versus neurologic quadriplegia

Functional quadriplegia (ICD-10-CM R53.2) is complete immobility due to severe physical disability or frailty. The Tabular List’s applicable language is complete immobility from severe disability or frailty—not paralysis from a spinal-cord or brain lesion. Neurologic quadriplegia or tetraplegia (category G82) is a different diagnosis. The Official Guidelines formerly had a separate functional-quadriplegia paragraph; that guideline was deleted effective October 1, 2017. Current teaching therefore follows the Tabular definition plus provider documentation, not a deleted guideline.

Nursing rows that say total care, a Barthel index of zero, or a high Braden risk score are indicators. They are not a diagnostic statement. Do not assign functional quadriplegia from an activities-of-daily-living flowsheet. Do not assign neurologic quadriplegia because someone wrote quad in a wound note for a contracted, bedbound patient without spinal injury. Functional quadriplegia has often grouped as an MCC when reported as a secondary diagnosis; verify the current IPPS CC/MCC assignment in DRG Expert. Developmental disorders (for example, intellectual disability or autism spectrum conditions documented as currently affecting care) sit on the same MDC 19 list as psychosis and dementia. They are reportable when they meet UHDDS secondary-diagnosis criteria for this encounter—evaluation, treatment, monitoring, or increased nursing care—not merely because they appear on an old problem list. Query only if the record is unclear whether the condition is active this stay.

Never query with MCC language. First-time capture uses multiple-choice, including an option that the immobility is explained by another documented condition without functional quadriplegia, plus Other, please specify.

Putting the toxicology and HIV queries together

Source every indicator: ethanol level, CIWA score, medication administration record, INR, naloxone, CD4 if obtained, antiretroviral list, injury mechanism, and nursing mobility scores. Offer only options the chart can support. Do not offer intentional self-harm when the record describes a clearly accidental extra dose. Do not offer B20 when the only language is HIV positive, on antiretrovirals, no prior opportunistic illness. Do not offer functional quadriplegia for a patient who is walking in the hall. Keep DRG, MCC, and HAC words out of the query. If you are validating a diagnosis already written that looks unsupported—severe malnutrition is the usual example, but the same pattern applies to functional quadriplegia or pneumocystosis copied from 2018—multiple-choice with confirmed with support, ruled out, no longer valid, and an alternative diagnosis is the 2026-preferred clinical-validation pattern.