Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Delirium


Related Terms

  • Acute Encephalopathy
  • Acute Organic Brain Syndrome

Differential Diagnosis

Specialists

  • Cardiovascular Internist
  • Internal Medicine Physician
  • Neurologist
  • Psychiatrist
  • Pulmonologist

Comorbid Conditions

  • Alcohol or substance abuse disorders
  • Dementia
  • Depressive disorders

Factors Influencing Duration

The nature and responsiveness to treatment of the underlying disorder greatly influence duration of disability. Individuals with terminal medical conditions, such as end-stage renal or liver disease, end-stage AIDS, or terminal cancer, show long-lasting symptoms of delirium. Individuals with higher premorbid performance in cognitive and physical areas generally have better recoveries.

Medical Codes

ICD-9-CM:
291.0 - Alcohol Withdrawal Delirium; Alcoholic Delirium; Delirium Tremens
292.81 - Drug-induced Delirium
293.0 - Delirium Due to Conditions Classified Elsewhere; Acute Confusional State, Infective Psychosis; Organic Reaction, Posttraumatic Organic Psychosis, Psycho-organic Syndrome; Acute Psychosis Associated with Endocrine, Metabolic, or Cerebrovascular Disorder; Epileptic Confusional State, Twilight State
293.1 - Subacute Delirium; Confusional State; Infective Psychosis; Organic Reaction; Posttraumatic Organic Psychosis; Psycho-organic Syndrome; Psychosis Associated with Endocrine or Metabolic Disorder

Overview

Delirium is a disturbance in consciousness and cognition (DSM-IV-TR) and a disturbance in attention and awareness (DSM-5)) that develops over a short period of time and tends to fluctuate in severity during the course of a day. Attention, concentration, speech, memory, or perceptions may be impaired. The Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR) specifies several types of delirium: delirium due to a general medical condition, substance-induced (either intoxication or withdrawal) delirium (drug of abuse, medication, or toxin exposure), delirium due to multiple etiologies, and delirium not otherwise specified. Delirium types specified in the DSM-5 are substance intoxication delirium, substance withdrawal delirium, medication-induced delirium, delirium due to another medical condition, delirium due to multiple etiologies, other specified delirium, and unspecified delirium. The disorder is considered to be a medical emergency associated with intensified morbidity and mortality.

This condition has several causes. General medical conditions causing delirium include low blood sugar (hypoglycemia) or other disturbances in blood chemistry, lack of oxygen (hypoxia), high fever (hyperthermia), infection of the brain or its coverings (encephalitis or meningitis), other massive infection (sepsis, endocarditis), liver or kidney failure, or head injury. Medications and drugs that may induce delirium include corticosteroids, pain medications, anti-asthma drugs, hallucinogens, cocaine, and alcohol withdrawal syndrome. Other causes may be disturbances in the sleep-wake cycle, or postoperative effects of anesthesia, blood loss, or other factors related to surgery. Delirium may have multiple causes or the cause(s) may be unknown.

It is not unusual for early symptoms such as restlessness, anxiety, disorientation, distractibility, or sleep disturbance to progress to delirium within 1 to 3 days. Delirium may lead to medical complications such as malnutrition, fluid and electrolyte abnormalities, pneumonia or skin ulcers (decubiti), or to institutional placement. Delirium is also associated with an increased risk of dying during hospitalization, due to underlying illnesses and increased risk of complications.

Incidence and Prevalence: According the DSM-IV-TR, the prevalence of delirium in the population is estimated to be 0.4% in adults 18 years of age and above, and 1.1% in individuals over age 55. In certain groups with medical comorbidities, the frequency increases markedly. Prevalence of delirium in the hospitalized medically ill ranges from 10% to 30%, with 25% of cancer patients, 30% to 40% of AIDS patients, and 80% of those with terminal illnesses developing delirium. Delirium is present in 10% to 15% of elderly patients at the time of hospital admission, with an additional 10% to 40% of patients developing the condition following admission. Delirium has been found in 40% of patients admitted to intensive care units. Prevalence of postoperative delirium following general surgery is estimated to be 5% to10% and as high as 42% following orthopedic surgery. As many as 80% of patients develop delirium near death. Studies suggest that up to 60% of elderly nursing home residents may experience delirium (DSM-IV-TR).

According the DSM-5, the prevalence of delirium is highest between hospitalized elderly individuals and varies with the individuals' characteristics, the setting of care, and the detection method. The prevalence of delirium in hospitalized individuals is 14-24%; the incidence of delirium during hospitalization is estimated in 6-56% in general hospital settings. There is delirium in 15-53% of postoperative older individuals and in 70-87% of those in the intensive care unit (ICU). The prevalence of delirium in the community is 1-2% but increases with age, up to 14% among individuals older than 85 years. The prevalence is 10-30% in elderly individuals in emergency departments, where the delirium often is contingent on a medical illness. Delirium occurs in up to 60% of individuals in nursing homes or post-acute care settings, and in up to 83% of individuals who are about to die.

Source: Medical Disability Advisor



Causation and Known Risk Factors

Older individuals appear to be more susceptible to delirium, perhaps because of physiological differences or changes associated with aging.

Source: Medical Disability Advisor



Diagnosis

History: According to the DSM-IV-TR, individuals with delirium have disturbance of consciousness (reduced clarity of awareness of the environment) with reduction of the ability to focus, sustain, or shift attention; a change in cognition (memory deficit, disorientation, language disturbance) or a perceptual disturbance that is not better explained by a preexisting, established, or evolving dementia; the disturbance usually appears over a short period of time (hours to days) and tends to fluctuate during the day. The history, physical examination, or laboratory findings reveal, in case of delirium due to a general medical condition (it is necessary indicate the general medical condition), that the disturbance is produced by the physiological consequences of a general medical condition; in case of substance-induced delirium (substance intoxication delirium), that the symptoms developed during substance intoxication, and medication use is etiologically related to the disturbance (this diagnosis is made instead of a diagnosis of substance intoxication only when the cognitive symptoms are in excess of those associated with the intoxication syndrome and when the severity of the symptoms warrants independent clinical attention); in case of substance withdrawal delirium, that the symptoms developed during, or shortly after, a withdrawal syndrome (this diagnosis is made instead of a diagnosis of substance withdrawal only when the cognitive symptoms are in excess of those associated with the withdrawal syndrome and the severity of the symptoms warrants independent clinical attention); in case of delirium due to multiple etiologies, that the delirium has more than one cause (more than one etiological general medical condition, a general medical condition plus substance intoxication or medication side effect). The category delirium not otherwise specified is used to diagnose a delirium that does not meet criteria for the other specific types of delirium (DSM-IV-TR).

According to the DSM-5, individuals with delirium have a disturbance in attention (reduction of the ability to direct, focus, sustain, and shift attention) and awareness (reduction of orientation to the environment); the disturbance appears over a short period of time (hours to a few days), represents a change from baseline attention and awareness, and its severity tends to fluctuate during the day; these disturbances are not better accounted for by another preexisting, established, or evolving neurocognitive disorder and do not occur in the presence of a severe reduction of the level of arousal, such as coma; there must also be another disturbance in cognition (memory deficit, disorientation, language, visuospatial ability, or perception). The history, physical examination, or laboratory findings reveal that the disturbance is a physiological consequence of another medical condition, substance intoxication or withdrawal (due to a drug of abuse or to a medication), exposure to a toxin, or may have multiple etiologies. The diagnosis of substance intoxication delirium should be made instead of substance intoxication when the disturbance in attention and awareness, and the additional disturbance in cognition, predominate in the clinical picture and when their severity warrant clinical attention. The diagnosis of substance withdrawal delirium should be made instead of substance withdrawal when the disturbance in attention and awareness, and the additional disturbance in cognition, predominate in the clinical picture and when their severity warrant clinical attention. The diagnosis of medication-induced delirium applies when the disturbance in attention and awareness, and the additional disturbance in cognition, are a side effect of a medication taken as prescribed. In delirium due to another medical condition the history, physical examination, or laboratory findings reveal that the disturbance is due to the physiological consequences of another medical condition. In delirium due to multiple etiologies the history, physical examination, or laboratory findings reveal that the delirium has more than one etiology (more than one etiological medical condition; another medical condition plus substance intoxication or medication side effect). It is necessary to specify if the disturbance is acute (lasting a few hours or days) or persistent (lasting weeks or months), and if the individual with the disturbance is hyperactive (hyperactive psychomotor activity that may coexist with mood lability, agitation, and/or refusal to cooperate with medical care), hypoactive (hypoactive level of psychomotor activity that may coexist with sluggishness and lethargy that approaches stupor), or has a mixed level of activity (a normal level of psychomotor activity even though attention and awareness are disturbed, or rapid fluctuation of the activity level) (DSM-5).

History is usually given by the family or caregiver, as the individual is often too confused to give a reliable history. Symptoms are generally worse at night (sundowning), when there are fewer environmental cues and less stimulation available. The individual may alternate between decreased states of alertness and consciousness (lethargy), with sluggishness and apathy, and hyperactive states. During periods of heightened arousal, there may be episodes of seeing or hearing things that aren't there (visual or auditory hallucinations), misinterpreting perceptions (illusions), false but persistent beliefs (delusions), or agitation. Visual hallucinations are most common, but there may also be hallucinations involving the sense of hearing (auditory), touch (tactile), taste (gustatory), or smell (olfactory). Illusions may cause the individual to misinterpret environmental stimuli, such as mistaking a banging door as a gunshot.

The individual is often unaware of his or her own altered state of consciousness, and may be confused and disoriented to person, place, or time. He or she may be unable to identify caregivers or family members, and may not know his or her location or the day, date, time, or year. Fear may cause the individual to attack caregivers because of perceived threats, or because of a delusion, such as, "They're trying to poison my food." Other emotional states may include anxiety, irritability, or euphoria. History may reveal a possible cause of delirium, such as a general medical condition such as low blood sugar (hypoglycemia) or other disturbance in blood chemistry, fever, infection, liver or kidney failure, head injury, alcohol withdrawal syndrome, terminal illness, AIDS, or recent use of a medication or drug (corticosteroids, pain medications, anti-asthma drugs, hallucinogens, cocaine).

Physical exam: In response to hallucinations or illusions, the individual may startle easily, talk to imagined voices, or pick at the air or bedclothes. They may be sleepy (lethargic) or overly alert and fearful (hypervigilant). They may be unable to focus on a conversational topic, be easily distracted, or continue to answer a previous question rather than shifting focus to a new topic (perseveration). Language may be disturbed, with slurred speech (dysarthria), inability to name objects (dysnomia), inability to write (dysgraphia), or exhibit rambling, irrelevant, or incoherent speech. General physical examination may reveal jaundice or enlarged liver (hepatomegaly) suggesting liver failure, bluish discoloration (cyanosis) or shortness of breath (dyspnea) suggesting lack of oxygen (hypoxia), fever suggesting infection, or other underlying cause of delirium. Neurological examination may reveal abnormal reflexes (frontal lobe release signs) suggesting diffuse brain involvement, or focal weakness suggesting dysfunction in a specific brain location, as might be seen with head trauma.

Tests: Verbal tests can be given to determine the individual's level of orientation, such as asking the names of family members or the time of day. Simple memory tests, such as asking the individual to recall items or count backwards, might be helpful. The Folstein Mini-Mental State Examination (MMSE), administered by the evaluating clinician, assesses for deficits in orientation, attention, memory, language, and visuoconstruction performance. Other screening strategies include the Confusion Assessment Method, the Delirium Rating Scale (DRS) and the Memorial Delirium Assessment Scale (MDAS). Caution should be used when using verbal or memory tests to ascertain levels of orientation, since education level and cultural background and differences could affect an individual's answers.

There are no specific diagnostic lab tests except those that might better define an underlying general medical condition or intoxication. An electroencephalogram (EEG) typically shows abnormal, generalized slowing or, occasionally, fast activity (alcohol withdrawal delirium). Blood work is needed to determine specific imbalances in blood chemistry that might be contributing to delirium. Arterial blood gas (ABG) tests, as well as a chest x-ray, and electrocardiogram (ECG), might be utilized if disease of the lungs or heart is suspected as the underlying cause. Cultures of blood and body fluids should be performed if systemic infection is suspected. Urine and blood drug screens or levels of specific medications are helpful is delirium is related to a specific substance.

Note: It must be kept in mind that just because a physical diagnosis cannot be established as the cause of the presenting symptomatology, it does not necessarily mean that the cause is a mental one. That is to say that the presence of medically unexplained symptomatology does not necessarily establish the presence of a psychiatric condition. The first step in identifying the presence of a mental disorder is excluding the presence of malingering and/or of factitious disorder. Although factitious disorder is conscious and purposeful, it is classified as a psychiatric disorder. The strong need for this step is especially true whenever there is a medicolegal context associated with the presenting problem(s). Additionally, using DSM-5 and/or ICD-9-CM or ICD-10-CM, the clinician will find that many presentations fail to fit completely within the boundaries of a single mental disorder. There are systematic ways to go about making psychiatric diagnoses, however.

Source: Medical Disability Advisor



Treatment

Identifying and treating the underlying medical condition is the first priority. If the delirium is related to use of a substance or medication, then the offending substance should be discontinued or changed. Alcohol withdrawal delirium requires medication management, usually with benzodiazepines, to prevent delirium, hallucinations, and seizures. An improvement in nutrition and in the general medical condition may decrease delirium symptoms. Treatment also includes strategies to protect the individual from wandering or self-injury, and reorientation activities. During the acute delirium phase, especially if the individual is hospitalized and attempting to pull out intravenous lines, and/or NG tubes, physical restraints or sedative medications might be required, but only as a last resort. Reorientation activities include environmental cues such as windows, large-faced clocks, calendars, and pictures of family members; speaking clearly and simply when communicating with the individual; and offering reassurances of safety. Antipsychotic medications may be needed for active hallucinations, but should be used sparingly, as any drugs may aggravate confusion and lethargy. Supportive and educational therapy for the family may also be helpful, and their presence may provide a calming and stabilizing effect. Preventive measures such as those used by the Hospital Elder Life Program may help identify individuals at risk for delirium, and ward off future episodes.

Source: Medical Disability Advisor



Prognosis

Many instances of delirium resolve within hours or days, especially if underlying conditions are treated. However, symptoms may persist in some individuals for months, or even until death. Most individuals who experience delirium recover fully, but delirium occasionally progresses to stupor, coma, seizures, and even death, especially if the underlying cause is not recognized or treated. Up to 60% of elderly individuals may have persisting symptoms of delirium. Although delirium is a bad prognostic sign in hospitalized patients, delirium in psychotic patients may paradoxically be a good sign that psychotic and affective symptoms may improve or even resolve.

Source: Medical Disability Advisor



Complications

Injury could result if the individual falls out of bed or gets entangled with intravenous lines or catheters. Medically ill individuals, especially the elderly, may have serious complications associated with delirium, including malnutrition, fluid and electrolyte abnormalities, pneumonia and decubitus ulcers. These individuals may exhibit functional decline or the inability to attend to daily activities such as feeding, dressing, toileting, or hygiene, which may lead to institutional placement. Postoperative delirium is associated with increased risk for complications, longer postoperative recuperation, and increased risk of long-term disability. Older individuals who develop delirium during a hospitalization may have up to a 20% to 75% chance of dying during that hospitalization. Up to 25% of older individuals with delirium die within a 6-month period of discharge from the hospital.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

The individual actively experiencing delirium should not work. If the individual is recovering from an illness-related or substance-related delirium, temporary work accommodations may include reducing or eliminating activities where the safety of self or others is contingent upon a constant and/or high level of alertness, such as driving motor vehicles, operating complex machinery, or handling dangerous chemicals; introducing the individual to new or stressful situations gradually under individually appropriate supervision; allowing some flexibility in scheduling to attend therapy appointments (which normally should occur during employee's personal time); promoting planned, proactive management of identified problem areas; and offering timely feedback on job performance issues. It will be helpful if accommodations are documented in a written plan designed to promote timely and safe transition back to full work productivity. If the individual has chronic side effects of a prolonged general medical illness, such as cardiac, liver, or nervous system damage, work should be limited to sedentary activities.

Risk: Risk of recurrence is dependent on the underlying condition causing the delirium, the presence of medical comorbidities, and the age of the individual.

Capacity: Because delirium is a medical emergency, capacity may be temporarily affected until the cause of the delirium is treated. If symptoms persist, disability may be permanent.

Tolerance: Tolerance factors depend on the underlying condition and the individual's response to treatment.

Accommodations: Employers willing to accommodate activities as needed can have employees return to work earlier.

Source: Medical Disability Advisor



Maximum Medical Improvement

MMI is expected at 3 weeks of treatment or less.

Note: MMI is estimated under the assumption that the vagaries involved in psychiatric diagnoses have been taken into consideration.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Because a comprehensive psychiatric and medical evaluation is essential in developing a treatment plan, did evaluation include a detailed history of past and present substance or medication use, a general medical and psychiatric history and examination, history of all prior psychiatric treatments with outcomes, family and social history, screening of blood, breath or urine for abused substances, and laboratory tests to help confirm the presence or absence of general medical conditions often associated with delirium, such as hypoglycemia or other disturbance in blood chemistry, fever, infection, liver or kidney failure, hypoxia, head injury, AIDS, or end-stage cancer? If evaluation was not this comprehensive, what areas were omitted? Would this information affect the current treatment plan? What changes can now be made?
  • Were other psychiatric disorders ruled out?
  • Since delirium may have multiple causes, were underlying medical disorders identified, treated, or ruled out?
  • Are any medications contributing to altered mental status?

Regarding treatment:

  • If medications are contributing to altered mental status, can these be changed or discontinued?
  • Is an improvement in nutrition or general medical condition decreasing delirium symptoms? Is underlying medical condition responding to treatment?
  • Was hospitalization required?
  • Did treatment include strategies to protect individual from wandering or self-injury?
  • Did therapy include reorientation activities?
  • Because supportive and educational therapy for the family may not only be helpful, but their presence may provide a calming and stabilizing effect, is family involved in the therapy process?

Regarding prognosis:

  • Was underlying cause identified? Is underlying cause being effectively addressed through a comprehensive treatment plan?
  • Is family actively involved in therapy process?
  • Were preventive measures initiated to identify and help ward off future episodes?

Source: Medical Disability Advisor



References

Cited

Diagnostic and Statistical Manual of Mental Disorders (DSM-5). 5th ed. American Psychiatric Association, 2013.

Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). 4th ed. Washington, DC: American Psychiatric Association, 2000.

Source: Medical Disability Advisor






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