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Acute Confusional State

Delirium is an acute confusional state that results from a sudden change in cerebral function. It occurs when there is an impairment in the normal signal pathway in the brain and it is usually temporary and reversible. Delirium manifests clinically as a wide range of neural and psychiatric abnormalities.


Obtaining a thorough history is very important for diagnosis of this condition as there are no medical investigations that can diagnose delirium. Delirious patients are often confused and unable to provide accurate information so the history should be obtained from relatives and caregivers. Some of the symptoms that would be mentioned are disorientation, difficulty is maintaining concentration, shifting attention, illusions, reversal in sleep-wake cycle and hallucinations. These symptoms are usually worse at night and show improvement during the day. Other neurological symptoms that could be reported are motor abnormalities, uremia, tremors, dysarthria and dysphagia [6].
Elderly patients who present with symptoms of delirium usually have an underlying illness precipitating it.

  • A 56-year-old female patient who presented with newly diagnosed diabetes mellitus and dry gangrene underwent a vascular bypass procedure while under general anesthesia. After extubation, the patient became disoriented and agitated.[ncbi.nlm.nih.gov]
  • CONCLUSIONS: Our study shows that hyposmia and RBD are significantly independent risk factors for postoperative delirium in general elderly population.[ncbi.nlm.nih.gov]
Sleep Apnea
  • Recent studies suggest that patients with obstructive sleep apnea (OSA), a sleep disorder characterized by repeated episodes of complete or partial blockage of the upper airway - are at greater risk to develop delirium.[ncbi.nlm.nih.gov]
  • In addition to its use for these indications olanzapine has also been used in the management of chemotherapy induced nausea and vomiting and otherwise difficult to control nausea and vomiting in palliative care settings.[ncbi.nlm.nih.gov]
  • We did not find any clear differences between the two groups in terms of duration of delirium (MD -3.6, 95% CI -15.6 to 8.4), adverse events (nausea, RR 0.30, 95% CI 0.01 to 6.29), use of rescue medications (RR 0.13, 95% CI 0.01 to 2.1), mortality (RR[ncbi.nlm.nih.gov]
  • There are several potential causes of these imbalances: Hypercalcemia, which is too much calcium in the blood Dehydration from not taking in enough fluids because of nausea, vomiting, or not being able to swallow comfortably.[cancer.net]
  • We did not find any clear differences between the two groups in terms of duration of delirium ( MD -3.6, 95% CI -15.6 to 8.4), adverse events (nausea, RR 0.30, 95% CI 0.01 to 6.29), use of rescue medications ( RR 0.13, 95% CI 0.01 to 2.1), mortality ([cochrane.org]
  • […] complications from alcohol withdrawal Usually generalized tonic-clonic seizures Symptoms of alcohol withdrawal, including: Anxiety, depression Fatigue Headache Insomnia (difficulty falling and staying asleep) Irritability or excitability Loss of appetite Nausea[medlineplus.gov]
Loss of Appetite
  • The presence of loss of appetite for more than two weeks may be the key to a diagnosis of WE.[ncbi.nlm.nih.gov]
  • […] of appetite Nausea, vomiting Nervousness, jumpiness, shakiness, palpitations (sensation of feeling the heart beat) Pale skin Rapid emotional changes Sweating, especially on the palms of the hands or the face Other symptoms that may occur: Chest pain[medlineplus.gov]
  • Melancholia implies the biological symptoms of depression: early-morning waking, daily variations of mood with depression most severe in the morning, loss of appetite and weight, constipation , and loss of interest in love and sex.[britannica.com]
Abdominal Pain
  • The sufferer experiences palpitations, dry mouth, dilatation of the pupils, shortness of breath, sweating, abdominal pain, tightness in the throat, trembling, and dizziness.[britannica.com]
  • […] hemorrhage, tumour, seizure disorder, Parkinson’s) H ypoxia (anemia, cardiac failure, pulmonary embolus) D eficiencies (vitamin B 12 , folic acid, thiamine) E ndocrinopathies (thyroid, glucose, parathyroid, adrenal) A cute vascular (shock, vasculitis, hypertensive[fammedref.org]
  • […] discharge and higher nursing home placement rates PATHOPHYSIOLOGY complex and poorly understood altered cerebral blood flow numerous biomarkers e.g. s100beta protein, neuron specific enolase, ILs RISK-FACTORS Baseline age preexisting dementia history of hypertension[lifeinthefastlane.com]
  • A focused assessment is often needed, with particular attention paid to vital signs (hypo/hypertension, fever/hypothermia, tachycardia, tachypnea), the state of hydration (mucus membranes, skin turgor), skin condition (decubiti, cellulitis) and potential[clinicaladvisor.com]
  • Some patients exhibit only mild tremulousness, irritability, difficulty in sleeping, an elevated pulse rate and hypertension, and increased temperature. Others have generalized convulsions as the first sign of difficulty.[medical-dictionary.thefreedictionary.com]
  • , cardiac arrhythmias, heart failure, hypoperfusion states, shock Vitamin deficiency Thiamin deficiency, vitamin B12 deficiency Withdrawal syndromes Alcohol, barbiturates, benzodiazepines, opioids Other causes Change of environment, fecal impaction, hypertensive[msdmanuals.com]
  • Its importance cannot be overemphasized, for acute confusion is a far more common herald of the onset of physical illness in an older person than are, for example, fever, pain or tachycardia." 7 The elderly, especially the very old, are uniquely prone[doi.org]
  • A focused assessment is often needed, with particular attention paid to vital signs (hypo/hypertension, fever/hypothermia, tachycardia, tachypnea), the state of hydration (mucus membranes, skin turgor), skin condition (decubiti, cellulitis) and potential[clinicaladvisor.com]
  • Unrelieved pain evokes a stress response characterized by tachycardia, increased myocardial oxygen consumption, hypercoagulability, immunosuppression, and persistent catabolism (5, 6).[doi.org]
  • […] excitement, restlessness, impaired memory, and incoherence. alcohol withdrawal delirium that caused by cessation or reduction in alcohol consumption, typically in alcoholics with many years of heavy drinking, characterized by autonomic hyperactivity, such as tachycardia[medical-dictionary.thefreedictionary.com]
  • Some patients may experience a great deal of free-floating anxiety, with frightening thoughts, fantasies, and dreams and with all the behavioral and physiologic expressions of the anxiety reaction—tremor, sweating, tachycardia, and so on.[doi.org]
  • The essestial features of delirium include: Acute onset (hours/days) and a fluctuating course Inattention or distraction Disorganized thinking or a altered level of consciousness Treatment of delirium, like dementia, is managed both pharmacologically[hopkinsmedicine.org]
  • Unfocused and distracted selectivity results in chaotic cognitions and the typical symptoms of delirium . Several terms are used to describe the deficits of delirium ; rarely are they defined, and often they are used loosely and inconsistently.[dictionary.cambridge.org]
  • At this point, it seems unlikely she'll be disoriented, distracted or disrupted by anyone. Download: On My Mind, Don't Panic, Lost And Found.[usatoday.com]
  • […] attention usually accompanied by disordered speech and hallucinations 2 : frenzied excitement he would stride about his room in a delirium of joy — Thomas Wolfe a crowd in a state of delirium Synonyms for delirium Synonyms agitation, deliriousness, distraction[merriam-webster.com]
  • Support healthy rest, sleep, and physical activity Decrease noise and distractions. Let in sunlight during the day, and keep the room dark at night. Keep lights low or off when resting.[uihc.org]
Visual Hallucination
  • Although she exhibited transient visual hallucinations during the delirium, she had no overt dementia. She developed no core clinical features of DLB and died of pneumonia at the age of 90 years.[ncbi.nlm.nih.gov]
  • Classic features of delirium tremens such as sympathetic overdrive and visual hallucinations were not salient features of his presentation.[ncbi.nlm.nih.gov]
  • For example, visual hallucinations are an indicator of an underlying metabolic disturbance or adverse effect of medication or substance abuse.[aafp.org]
Aggressive Behavior
  • The forensic pathologist should consider cocaine-induced excited delirium when an individual exhibits aggressive behavior, unexpected strength, and resistance to pain who dies suddenly.[ncbi.nlm.nih.gov]
  • CASE REPORT: We report a cluster of 7 patients who experienced a spectrum of anxiety, delirium, psychosis, and aggressive behaviors after smoking the same SC-containing product at a party.[ncbi.nlm.nih.gov]
Ganser Syndrome
  • —The hysterical psychosis (including the Ganser syndrome, pseudodementia, and prison psychosis) may simulate delirium}.[doi.org]
  • Valproic acid was effective in treatment of agitation and well tolerated.[ncbi.nlm.nih.gov]
  • Wake Up and Breathe Flowchart Choice of Analgesia and Sedation  Richmond Agitation-Sedation Scale (RASS) Riker Sedation-Agitation Scale (SAS) Level of Arousal Assessment Conversions MDCalc iOS and Android app Protocol for Management of Pain, Agitation[icudelirium.org]
  • Following discontinuation of dexmedetomidine, her fever, agitation and delirium ceased. We depict the first known case of dexmedetomidine causing high fevers and delirium.[ncbi.nlm.nih.gov]
  • It can be considered when agitation cannot be controlled with medical treatment, when agitation and delirium make weaning impossible, or prolonged deep sedation the only alternative. Copyright 2014 Elsevier Inc. All rights reserved.[ncbi.nlm.nih.gov]
  • Antipsychotics are effective in treating hallucinations and agitation, but do not reduce the duration of delirium.[ncbi.nlm.nih.gov]
  • MAIN OUTCOMES AND MEASURES: Delirium was detected using the Confusion Assessment Method and categorized in hypoactive, hyperactive, or mixed delirium.[ncbi.nlm.nih.gov]
  • Patients were scored for 'hyperactive' or 'hypoactive' symptoms, and then the 125 patients with DSM-III delirium were rated as 'hyperactive type' (15%), 'hypoactive type' (19%), 'mixed type' (52%), or 'neither' (14%).[ncbi.nlm.nih.gov]
  • It is well known that delirium and psychosis can arise following the administration of oral corticosteroids but there are few documented cases of the development of acute hyperactive delirium with psychosis following intra-articular administration.[ncbi.nlm.nih.gov]
  • There are two types of delirium: hyperactive delirium and hypoactive delirium. Hyperactive means overactive (agitation, restlessness), while hypoactive means underactive (sleepy and hard to respond). Sometimes both types can occur together.[my.clevelandclinic.org]
  • Excited delirium denotes a life-threatening medical condition characterized by the acute onset of agitated and violent behavior that often results in a sudden and unexplained death.[ncbi.nlm.nih.gov]
  • Prehospital ketamine is a safe and effective treatment for excited delirium in a community hospital based EMS system. Prehosp Disaster Med. 2016;31(5):563-569.[ncbi.nlm.nih.gov]
  • This case study presents a 37-year-old male who was experiencing excited delirium (ExD) and died in a county jail 4 days after being taken into custody.[ncbi.nlm.nih.gov]
  • He developed an excited delirium syndrome at the second day after stopping. Apparently even after relatively short recreational use severe disruptive behavior can develop. This is a unique case in literature. References are provided.[ncbi.nlm.nih.gov]
  • ‘I ended up getting a digital keyboard, which was so amazing to me - excitement to the point of delirium.’ ‘The smell of incense filled the room and transported me, in my delirium, back to my youth as a Miami altar boy.’[en.oxforddictionaries.com]
  • At 11-month follow-up, only mild executive dysfunction and persistent right postural tremor was noted, MRI showed partial regression of subcortical and juxtacortical lesions.[ncbi.nlm.nih.gov]
  • Alcoholic delirium—called delirium tremens because of the characteristic tremor—is a result not merely of excessive consumption of alcohol but of a complicating exhaustion, lack of food, and dehydration ; prior to the outbreak of delirium, the patient[britannica.com]
  • Symptoms may get worse quickly, and can include: Delirium, which is sudden severe confusion Body tremors Changes in mental function Agitation, irritability Deep sleep that lasts for a day or longer Excitement or fear Hallucinations (seeing or feeling[medlineplus.gov]
  • […] quiet Be unusually aggressive Use inappropriate words Be unable to pay attention or follow directions See or hear things that are not there Be unaware of their surroundings Act differently than normal Have memory problems Undergo emotional changes May tremor[centrahealth.com]
  • Other neurological symptoms that could be reported are motor abnormalities, uremia, tremors, dysarthria and dysphagia. Elderly patients who present with symptoms of delirium usually have an underlying illness precipitating it.[symptoma.com]


There is no one test for diagnosing delirium, but there are numerous tests that could be useful for diagnosing precipitating symptoms. Blood tests like complete blood count, sedimentation rate and bacterial/viral culture are used to rule out underlying infections. Blood tests also help to detect electrolyte derangement and problems with glucose metabolism. They are useful to determine renal, hepatic and thyroid function. Urine tests are also used to check for infections and toxicology screening to check for drugs and poisons. HIV tests and tests for vitamin B12 and thiamine are also carried out.

Imaging studies are also done to check the structure of the brain and they include CT scans and MRI. Electroencephalogram (EEG) is also useful in delirium as it may also give an indication to the cause of the delirium based on the wave patterns. A chest radiograph also is used diagnose congestive heart failure or pneumonia.

Other tests like lumbar puncture is done when a CNS infection is suspected. Pulse oximetry to diagnose hypoxia and ECG if an arrhythmia or ischemia is suspected as the underlying cause [7].


The most important step in treatment is to identify the underlying cause and eliminate it. The mainstay of delirium treatment is supportive therapy and drug therapy.
Supportive therapy involves maintaining normal hydration as nutrition levels. Thiamine should be given to patients who are undergoing alcohol withdrawal. It is important for the patient’s environment to be quiet, stable and well-lit.

Memory cues like clocks, family photos and calendars are useful in reorientation. Reorientation should be reinforced by family members. Sensory defects should be corrected as required. It is important to avoid physical restraints as it only heightens the patient’s perception of problems and could lead to combative behaviour. It is important that these patients are closely monitored and never left alone [8].

Medication should be considered in patients who cause injuries to themselves or others. Medications used include neuroleptics like haloperidol and risperidone and short-acting sedatives like lorazepam. Sedatives are used in patients withdrawing from alcohol or sedative hypnotics [9].


There are mortality rates of up to 26% in patients admitted with delirium. Patients who develop delirium in the hospital have a mortality rate of up to 76%. For post-operative and elderly patients, delirium could lead to extended hospital stay, increased complications, extra costs and disability [5].


Delirium is often a result of conditions that impair the supply of oxygen and other substances in the brain. Some of the causes include infections like urinary tract infections (UTI) and pneumonia, dehydration, metabolic derangements, withdrawal symptoms from alcohol and drugs, drug toxicity, chemicals, seizures, head injuries, surgeries and chronic illnesses amongst others [2].


It is a fairly common condition and is seen is about 14 to 56% of hospitalized elderly patients. Up to 30% of cases develop after admission and 40% of patients admitted to intensive care units develop delirium. The prevalence of post-surgical delirium is also high with as high as 40% of patients developing delirium after orthopaedic surgery. Delirium is also very common in nursing home residents and as much as 80% of people develop delirium near death. It has no race or sex predilection [3].

Sex distribution
Age distribution


There are 3 recognizable delirium types based on the state of arousal. Hyperactive delirium is associated with intoxication with some stimulant drugs or withdrawal from alcohol. Hypoactive delirium is seen in patients with hepatic encephalopathy. In the third type, mixed delirium, there is usually sedation during the day and at night, patients develop behavioural problems.

There has been no clear understanding of the mechanism by which delirium occurs as it results from various psychological and physical insults. The widely accepted hypothesis is that there are multiple neurotransmitter abnormalities and reversible impairment of the cerebral oxidative mechanism. Observations such as reduced cholinesterase activity and increased dopaminergic activity support the hypothesis of neurotransmitter abnormalities [4].


There is no specific prevention for delirium as it is a consequence of various other conditions. The preventive measures implemented for specific conditions which cause disturbance in cerebral function can indirectly prevent delirium.


Delirium is a syndrome that results from multiple causes that have similar type of symptoms. Early diagnosis and resolution of symptoms are important to avoid morbidity and mortality. It is a medical emergency and should be treated as one [1].

Patient Information

  • Definition: Delirium is a sudden change in brain function that results when there is an interruption in the sending and receiving of signals in the brain. It is characterised by hallucinations and decreased awareness.
  • Cause: Delirium is often seen in patients who have prolonged stay in the hospital, especially the intensive care unit. It is caused by a problem with neurotransmitter function and a problem with oxygen mechanism in the brain. Some of the things that could lead to this include infections, drugs and drug withdrawal, seizures, head injuries, surgeries and long term illnesses.
  • Symptoms: Some of symptoms to look out for include change in mood, difficulty concentrating, hallucinations, confusion, change in sleep pattern, movement disorders and incontinence.
  • Diagnosis: This is usually made based on the symptoms and sign. Some tests may however be needed to check for the possible causes. Blood tests will check for infection, glucose level, electrolyte level, and the kidney, liver and thyroid functions. Imaging studies may also be carried out on the brain to check the structure and activity.
  • Treatment: The treatment is usually supportive. The family members and caregivers are essential for this step. It involves helping the patient remember and slowly integrate him into his normal life. Fluid and nutrition are given and drugs are used in some special cases [10].



  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. 5thed. Washington, DC: American Psychiatric Association; 2013.
  2. de Rooij SE, van Munster BC, Korevaar JC, Levi M. Cytokines and acute phase response in delirium. J Psychosom Res. May 2007;62(5):521-5.
  3. Ebersoldt M, Sharshar T, Annane D. Sepsis-associated delirium. Intensive Care Med. Jun 2007;33(6):941-50.
  4. Limosin F, Loze JY, Boni C, et al. The A9 allele of the dopamine transporter gene increases the risk of visual hallucinations during alcohol withdrawal in alcohol-dependent women. Neurosci Lett. May 20 2004;362(2):91-4.
  5. Folstein MF, Folstein SE, McGugh PR. "Mini- Mental State". A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. Nov. 1975;12(3):189-98.
  6. Cole M, McCusker J, Dendukuri N, Han L. The prognostic significance of subsyndromal delirium in elderly medical inpatients. J Am Geriatr Soc. Jun 2003;51(6):754-60.
  7. Van Rompaey B, Elseviers M M, Van Drom W, Fromont V, Jorens P G. The effect of earplugs during the night on the onset of delirium and sleep perception: a randomized controlled trial in intensive care patients.Critical Care. 2012;16.
  8. Anderson CP, Ngo LH, Marcantonio ER. Complications in Postacute Care Are Associated with Persistent Delirium. J Am Geriatr Soc. May 30 2012
  9. Bergeron N, Dubois MJ, Dumont M, Dial S, Skrobik Y. Intensive Care Delirium Screening Checklist: evaluation of a new screening tool. Intensive Care Med. 2001;27:859-864.
  10. Inouye SK, Charpentier PA. Precipitating factors for delirium in hospitalized elderly persons. Predictive model and interrelationship with baseline vulnerability. JAMA. Mar 20 1996;275(11):852-7.

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Last updated: 2019-07-11 22:47