Confusion
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S.[2]
Synonyms and keywords: Disorientation
Overview
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
Overview
Confusion refers to mental dysfunction in which a lack of attention and disorientation occurs with the inability to think with normal speed or clarity. It is the inability to maintain a coherent stream of thought or action.
Pathophysiology
Confusion results from global impairment of brain functions. Some areas of the brain are identified for various presentations of confusion. Drugs, poisons, and chemicals interact with the neurotransmitters and can cause confusion. Inflammatory agents are involved in conditions such as a fever.
Causes
Confusion is a common symptom associated with various diseases and metabolic disorders. Common causes of confusion include insults to the central nervous system (CNS), metabolic disorders, and side effects of medications or illicit drugs.
Differentiating Confusion from other Diseases
Various conditions such as dementia, depression and amnesia involve confusion as part of their presentation. Obtaining a clear history about the onset of symptoms, and the onset of confusion in association with other symptoms, helps in differentiating confusion from other conditions.
Epidemiology and Demographics
Nearly about 30% of older patients admitted for medical conditions are confused at some point of time during their admission.[1] In surgical wards the chances of confusion ranges from 10-50%.[2] Increasing rates are seen in patients admitted to intensive care units and in hospice care. There is no significant difference in the distribution based upon gender or race.
Risk Factors
Increasing age, admission to the hospital, post-surgical status, alcoholism, and underlying brain lesions are a few important risk factors for confusion. Special care is required for elderly patients who are hospitalized.
Natural History, Complications and Prognosis
Confusion is a disturbance in mental status which develops rapidly. If untreated it develops into a stupor / coma. Confusion caused by metabolic changes can be rapidly corrected and have good prognosis compared to the one caused by underlying structural abnormalities of the brain. The mortality rate for those who developed confusion at a hospital is nearly 39% in the first year which is nearly twice compared to age matched controls.[3]
Diagnosis
History and Symptoms
Confused patients will not be able to provide a coherent history. Confirming the history with a patient’s caregiver is the key to obtaining an accurate history about the patient. Determining the patient’s drug history and co morbid conditions is very important. In young patients drug abuse and withdrawal should be evaluated. Some assessment scales are used to identify and diagnose confusion, and they include the Confusion Assessment Method, Mini Mental Status Examination, and The Neelon and Champagne (NEECHAM) Confusion Scale.
Physical Examination
In cases of confusion, a physical examination helps in localizing the lesion if the cause is from the brain. It also gives clues to the underlying cause of the disease. A complete neurological examination may not be done due to a limitation of the patient’s condition.
Laboratory Findings
Several laboratory tests are available for evaluating confusion. It is a physician’s role to choose the most useful test based upon the history of the person. For example, a patient presenting with confusion, severe neck stiffness, headaches, and fever should be evaluated for infective foci.
Electrocardiogram
Various heart conditions can cause hypoperfusion of the brain. This hypoperfusion can be a cause of confusion. An electrocardiogram can help to identify any associated heart conduction problems, which helps in the diagnosis.
Chest X Ray
Lung pathologies usually cause hypoxia and confusion if left untreated. A chest x ray is the most important tool to evaluate such conditions. It can be very helpful in identifying various lung lesions and infections.
CT
A CT scan of the head is an important diagnostic tool in cases of confusion where a cause couldn’t be established. Before a lumbar puncture is done, a CT scan is the first test used in cases of suspected infections such as meningitis.
MRI
An MRI scan is more sensitive in identifying intra cranial lesions than a CT scan. It can be used in cases with a high index of suspicion and a negative report on a CT scan.
Echocardiogram or Ultrasound
An echocardiogram is a valuable tool in assessing the cardiac output. It also helps in determining the perfusion. An ultrasound is used for determining the cause of confusion in certain abdominal conditions such as any liver injuries, abdominal bleeds, and injuries to the major abdominal vessels.
Other Imaging Findings
There are several other imaging studies that are not used as often for diagnosis. They are mostly used in cases of an unconfirmed diagnosis. Examples of these tests include CT angiography and FLAIR (Fluid attenuated inversion recovery images).
Other Diagnostic Studies
Certain studies, such as electroencephalography (EEG), are of noticeable importance. These tests are done to exclude other diseases and aid in the diagnosis of certain conditions.
Treatment
Medical Therapy
Complete evaluation of the patient in an emergency department has to be done, which is followed by the administration of appropriate treatment. Every confused individual should be administered with glucose and thiamine, followed by naloxone and flumazenil. Treatment must be started while waiting for the results. Early treatment can save the individual from long term effects.
Surgery
Surgical options are limited for confusion because it all depends on the cause of confusion. Some conditions, such as a subdural hematoma that can be drained, are surgically evacuated. In such cases, a consultation with a neurosurgeon may be needed. In cases of traffic accidents, a person may be bleeding severely due to fractures and visceral injury. In such cases, an orthopedic surgeon would most likely be needed.
References
- ↑ Francis J (1992). “Delirium in older patients”. J Am Geriatr Soc. 40 (8): 829–38. PMID 1634729. Unknown parameter
|month=ignored (help) - ↑ Dyer CB, Ashton CM, Teasdale TA (1995). “Postoperative delirium. A review of 80 primary data-collection studies”. Arch. Intern. Med. 155 (5): 461–5. PMID 7864702. Unknown parameter
|month=ignored (help) - ↑ Inouye SK, Charpentier PA (1996). “Precipitating factors for delirium in hospitalized elderly persons. Predictive model and interrelationship with baseline vulnerability”. JAMA. 275 (11): 852–7. PMID 8596223. Unknown parameter
|month=ignored (help)
Pathophysiology
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S. [2]
Overview
Confusion results from global impairment of brain functions. Some areas of the brain are identified for various presentations of confusion. Drugs, poisons, and chemicals interact with the neurotransmitters and can cause confusion. Inflammatory agents are involved in conditions such as a fever.
Pathophysiology
Confusion is a commonly used term for any kind of altered mental status, inability to pay attention or to making decisions. Confusion is seen in various conditions and caused by many drugs, poisons, and chemicals. Various theories are postulated for the development of confusion.
- Lesions involving the ascending reticular activating system causes disturbances in arousal.
- Lesions involving non-dominant frontal and parietal lobes causes disturbances in attention.
- Lesions of the cortex will cause disturbances in the insight and judgement capacity of the individual.
Delirium is a type of confusional state which develops suddenly and causes rapid changes in brain function.
- Disturbances in the global function of the brain leads to delirium.
- Certain diseases and strokes cause confusion. There is evidence to support a sub cortical mechanism for confusion.[1]
- Certain drugs have anticholinergic properties which can impair brain function in elderly people and when used in high doses.[2]
- In certain conditions, post surgical recovery states can induce cytokine activation, which may be the cause for confusion.
- Certain metabolic states like hypoglycemia, electrolyte abnormalities, and hypoxia cause global brain dysfunction leading to confusion.
References
- ↑ Trzepacz PT (1994). “The neuropathogenesis of delirium. A need to focus our research”. Psychosomatics. 35 (4): 374–91. doi:10.1016/S0033-3182(94)71759-X. PMID 7916159.
- ↑ Mach JR, Dysken MW, Kuskowski M, Richelson E, Holden L, Jilk KM (1995). “Serum anticholinergic activity in hospitalized older persons with delirium: a preliminary study”. J Am Geriatr Soc. 43 (5): 491–5. PMID 7730529. Unknown parameter
|month=ignored (help)
Causes
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S.[2]
Overview
Confusion is a common symptom associated with various diseases and metabolic disorders. Common causes of confusion include insults to the central nervous system (CNS), metabolic disorders, and side effects of medications or illicit drugs.
Causes
Common Causes
- Alzheimer’s disease
- Hyperthyroidism
- Hypothyroidism
- Kidney failure
- Liver failure
- Myxedema coma
- Respiratory infection
- Schizophrenia
- Sepsis
- Urinary tract infection
Causes by Organ System
Causes in Alphabetical Order
References
Differentiating Confusion from other Symptoms
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S. [2]
Overview
Various conditions such as dementia, depression and amnesia involve confusion as part of their presentation. Obtaining a clear history about the onset of symptoms, and the onset of confusion in association with other symptoms, helps in differentiating confusion from other conditions.
Differentiating Confusion from other Symptoms
Confusion : Is the inability to maintain a coherent stream of thought or action. It can be caused by various conditions. An altered level of consciousness is seen in confusion. Confusion can be a predecessor for successive stupor or coma.
Delirium : Acute impairment in attention with fluctuating course and altered level of consciousness caused by a medical condition. This is also called an acute confusional state and encephalopathy.
Dementia : Chronic degenerative condition affecting memory, behavior and cognition.
Depression : A clinical term for a state of intense sadness, melancholia or despair that has advanced to the point of being disruptive to an individual’s social functioning and/or activities of daily living.
Amnesia : A condition in which memory is disturbed or lost. It can be due to organic or functional.
Seizures : Certain seizures such as absence seizure may appear to be similar to confusion.
A few symptoms which help in differentiating confusion
- Worsening of symptoms at night time –> Sundowning
- Rapid improvement over seconds –> Post-syncope
- Rapid improvement over minutes to hours –> Post-ictal state
- Worsening of symptoms on standing –> Hypoperfusion
Taking a careful history from the people that are with the patient will be important, as the patient themselves are not always able to give a good history due to their confused state. Key features include the onset of symptoms, what might have caused them, the speed of progression of symptoms, and whether this has occurred before. Chronic problems with memory point more towards conditions such as dementia and amnesia. The presence of psychiatric symptoms will warrant further detailed history from the patient or family members. In children, absence seizures may appear to be confusion, as it is accompanied by vague spells of staring and loss of attention. Finding a history of drugs, poisons or chemicals in concordance with the symptoms can provide definitive clues for the diagnosis of confusion.
Some assessment tools, such as the Confusion Assessment Method (CAM), can be used to differentiate confusion from dementia. This tool is handy for physicians who are not quick in psychiatric assessment.[1]
References
- ↑ “National Guideline Clearinghouse | Acute confusion/delirium”. Retrieved 2013-02-08.
Epidemiology and Demographics
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S. [2]
Overview
Nearly 30% of older patients admitted for medical conditions are confused at some point of time during their stay at the hospital.[1] In surgical wards the probability of confusion ranges from 10-50%.[2] Increasing rates are seen in patients admitted to intensive care units and in hospice care. There is no significant difference in the distribution based upon gender or race.
Epidemiology and Demographics
Age
Increasing age is associated with an increased risk of confusion. This in part due to the increased risk of stroke associated with older age as well as an increased risk of metabolic disorders as well as side effects from drugs.
Gender
In general, there is no association of gender with confusion, although a few studies demonstrate an association of male gender with confusion.[3]
Race
Race is not associated with confusion.
References
- ↑ Francis J (1992). “Delirium in older patients”. J Am Geriatr Soc. 40 (8): 829–38. PMID 1634729. Unknown parameter
|month=ignored (help) - ↑ Dyer CB, Ashton CM, Teasdale TA (1995). “Postoperative delirium. A review of 80 primary data-collection studies”. Arch. Intern. Med. 155 (5): 461–5. PMID 7864702. Unknown parameter
|month=ignored (help) - ↑ Edlund A, Lundström M, Karlsson S, Brännström B, Bucht G, Gustafson Y (2006). “Delirium in older patients admitted to general internal medicine”. J Geriatr Psychiatry Neurol. 19 (2): 83–90. doi:10.1177/0891988706286509. PMID 16690993. Unknown parameter
|month=ignored (help)
Risk Factors
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S. [2]
Overview
Increasing age, admission to the hospital, post-surgical status, alcoholism, and underlying brain lesions are common risk factors in the development of confusion.
Risk Factors
The risk factors of confusion can be grouped in two main categories; factors which involve underlying brain conditions, and certain conditions which are known to precipitate confusion.[1]
- Increasing age is one of the most significant risk factors
- Hospitalization
- Post surgical recovery
- Admission into intensive care unit
- Drug abuse
- Alcoholism
- Multisystem organ failure
Underlying Brain Conditions
Precipitating Factors
- Hypoxia
- Hypoglycemia
- Poisonings
- Infections
- Dehydration
- Electrolyte abnormalities
- Prolonged immobility
- Head injury
- Kidney failure
- Liver failure
References
Natural History, Complications and Prognosis
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S. [2]
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Overview
Confusion is a disturbance in mental status which develops rapidly. If untreated it develops into a stupor / coma. Confusion caused by metabolic changes can be rapidly corrected and have good prognosis compared to the one caused by underlying structural abnormalities of the brain. The mortality rate for those who developed confusion at a hospital is nearly 39% in the first year which is nearly twice compared to age matched controls.[1]
Natural History
Confusion is differentiated from similar symptoms by its rapidity of onset, which is different from dementia or depression. In hospitalized patients, certain prodromal signs may be evident. They include irritability, sleep disturbances, excessive fatigue. Detection of these early signs is important in helping to make a difference in the course of the disease. Unnoticed symptoms may lead to behavioral changes leading to a hypo active stage that can later turn into an agitated individual. In cases of poisoning or drug overdose onset of symptoms is rapid too and history of abuse or exposure is obtained. Metabolic derangement can be identified with laboratory tests and necessary precautions can be taken to avoid confusion. Undetected prodrome or rapid onset of confusion can cause severe cognitive impairment. It can progress from days to weeks depending on the underlying cause. Undetected or untreated confusion can lead to stupor/coma.
Prognosis
Prognosis depends on the cause of confusion.
- Confusion due to metabolic derangement like hypoglycemia and hypokalemia can be rapidly corrected and will typically have a good prognosis.
- Confusion due to underlying structural lesions of the brain may not have a very good prognosis.
- Confusion caused by chemicals and poisons need a thorough assessment of the condition. Detoxification will result in a good prognosis.
- Other underlying diseases can precipitate confusion, annd in such cases, the prognosis depends on the severity of the causative disease.
- Some symptoms can persist as long as 6 months.[2]
- Patients who developed confusion during a hospital stay can prolong their time in the hospital.
References
- ↑ Inouye SK, Charpentier PA (1996). “Precipitating factors for delirium in hospitalized elderly persons. Predictive model and interrelationship with baseline vulnerability”. JAMA. 275 (11): 852–7. PMID 8596223. Unknown parameter
|month=ignored (help) - ↑ Francis J, Martin D, Kapoor WN (1990). “A prospective study of delirium in hospitalized elderly”. JAMA. 263 (8): 1097–101. PMID 2299782. Unknown parameter
|month=ignored (help)
Diagnosis
Diagnosis
History and Symptoms | Physical Examination | Laboratory Findings | Electrocardiogram | Chest X Ray | CT | MRI | Echocardiography or Ultrasound | Other Imaging Findings | Other Diagnostic Studies
Treatment
Treatment
Medical Therapy | Surgery | Primary Prevention | Secondary Prevention | Cost-Effectiveness of Therapy | Future or Investigational Therapies
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