Opioid use disorders

Part 2 of 2

This month's column reviews opioid-induced conditions, which are complications directly due to opioid use disorder.

Last month's column addressed opioid use disorder (OUD), connecting the definitions and diagnostic criteria of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), with the 2018 International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), documentation and coding requirements.

Photo by Thinkstock
Photo by Thinkstock.

This month's column will address opioid-induced conditions, which are complications directly due to OUD. Most of these conditions also occur independently of OUD. ICD-10-CM requires that the clinician specifically document a connection between these conditions and OUD for them to be coded as “opioid-induced.” DSM-5 diagnostic criteria also require that other causes be ruled out before attributing a condition to opioids.

DSM-5 lists and defines certain opioid-induced conditions. Oddly, ICD-10-CM has codes for a slightly different set of opioid-induced conditions (Table 1). ICD-10-CM provides multiple codes in category F11 that combine OUD and associated conditions into one code based on the use/abuse/dependence distinction and clinical circumstances (Table 2). ICD-10-CM uses the term “uncomplicated” to identify OUD without an opioid-induced condition.

One difference is that DSM-5 specifically lists opioid-induced anxiety disorder but ICD-10-CM does not. Additionally, ICD-10-CM includes codes for opioid-induced psychosis, but DSM-5 makes no specific provision for it.

Opioid withdrawal is defined by DSM-5 as the occurrence of three or more specified symptoms developing within minutes to several days following cessation or reduction of opioid use that has been heavy and prolonged for several weeks or longer, or upon administration of an opioid antagonist (Table 3). Symptoms should cause significant impairment or distress and should not be attributable to another condition.

ICD-10-CM assumes that opioid withdrawal requires dependence (moderate, severe, or severity-unspecified OUD). It does not provide a withdrawal code for abuse (mild OUD). Unlike in alcohol use disorder, there are only two possible codes for opioid withdrawal: F11.23 with dependence and F11.93 when severity is not specified. Withdrawal is not considered a toxic encephalopathy or an adverse effect (poisoning) of an opioid since it is caused by withdrawal of the drug.

Opioid intoxication is an opioid-induced condition defined by DSM-5 as problematic behavioral or psychological changes (not associated with another condition) characterized by pupillary constriction (pupillary dilation, if severe overdose) plus one or more of three symptoms: drowsiness or coma, slurred speech, or impaired attention or memory. Intoxication may be further specified as occurring with delirium or with perceptual disturbances (e.g., hallucinations or sensory illusions) without loss of reality testing (psychosis). ICD-10-CM provides matching codes for these complications of opioid intoxication.

Opioid intoxication accompanied by delirium is generally consistent with an acute encephalopathy due to opioid. According to DSM-5, when this occurs, both encephalopathy (code G93.40) and opioid-induced delirium (sequenced after G93.40) should be documented and coded pursuant to ICD-10-CM. Delirium should be considered a symptomatic mental disorder caused by encephalopathy, which is the underlying functional brain abnormality.

Even though DSM-5 makes no provision for opioid-induced psychosis, the characteristic features of psychoses are loss of reality testing, delusions, and/or hallucinations. If an apparent psychotic episode seems to be opioid-induced, make sure it does not represent intoxication delirium or perceptional disturbance before using the ICD-10-CM code for opioid-induced psychosis.

Other opioid-induced disorders may result from OUD: mood disorders, sexual dysfunction, and sleep disorders. DSM-5 identifies 10 sleep disorders or groups of disorders, some of which may be opioid-induced, such as insomnia, hypersomnia, and circadian rhythm disturbance, and others, such as narcolepsy and sleep apnea, which are not.

Finally, clinicians may decide that another condition not specifically listed by ICD-10-CM as an opioid-induced disorder is actually caused by opioids, for example, opioid-induced anxiety. In this case an “other opioid-induced disorder” code (F11.288) would be assigned.

In summary, for diagnosis and coding of opioid-induced conditions, the ICD-10-CM code classification generally follows DSM-5 definitions. Clinicians must determine whether a patient has mild, moderate, or severe OUD based on the DSM-5 diagnostic criteria, as well as documenting any opioid-induced conditions. Clarification of whether a particular condition is due to OUD or not is always needed in the medical record.

A general understanding and basic working knowledge of the diagnostic standards and interrelationships of these conditions contributes to quality of care, precise documentation, and accurate coding and reporting.