Diagnosis
Using the DSM-5 criteria for delirium as framework, the early recognition of signs/symptoms and a careful history, along with any of multiple clinical instruments, can help in making a diagnosis of delirium. A diagnosis of delirium cannot be made without a previous assessment of the patients baseline level of cognitive function. In other words, a mentally-disabled or impaired person might appear to be delirious, but may actually just be operating at their baseline mental ability. General setting
Multiple guidelines recommend that delirium should be diagnosed when it presents to healthcare services. Much evidence reveal, however, that delirium is greatly under-diagnosed. Higher rates of detection of delirium in general settings can be assisted by the use of validated delirium screening tools. Many such tools have been published. They differ in duration, complexity, need for training, etc. Examples of tools in use in clinical practice are:

Richmond Agitation and Sedation Scale (RASS) – highly sensitive and specific for diagnosing delirium in older patients
Observational Scale of Level of Arousal (OSLA) – highly sensitive and specific for diagnosing delirium in older patients
Confusion Assessment Method (CAM)
Delirium Observation Screening Scale (DOS)
Nursing Delirium Screening Scale (Nu-DESC)
Recognizing Acute Delirium As part of your Routine (RADAR)
4AT (4 As Test)
Delirium Diagnostic Tool-Provisional (DDT-Pro), also for subsyndromal delirium

Intensive care unit
People who are in the ICU are at greater risk of delirium and ICU delirium may lead to prolonged ventilation, longer stays in the hospital, increased stress on family and caregivers, and an increased chance of death.
Other side effects. The most common side effects are stomach problems (including vomiting, diarrhea, and nausea), and effects on blood cells (including low red blood cells count, low white blood cell count, low platelet count, fever, and infection). Clofarabine can also cause tachycardia and can affect the liver and kidneys. Contraindications
pregnancy or planned pregnancy
breast-feeding
liver problems
kidney problems

Drug interactions
nephrotoxic drugs
hepatotoxic drugs

Delivery
By intravenous infusion. Dosage is a 2-hour infusion (52 mg/m2) every day for five days. The cycle is repeated every 2 to 6 weeks. Regular blood tests to monitor his or her blood cells, kidney function, and liver function. Biology
Clofarabine is a second-generation purine nucleoside analog designed to overcome biological limitations observed with ara-A and fludarabine. A 2´(S)-fluorine in clofarabine significantly increased the stability of the glycosidic bond in acidic solution and toward phosphorolytic cleavage as compared to fludarabine. A chlorine substitution at the 2-position of the adenine base avoids production of a 2-fluoroadenine analog, a precursor to the toxic 2-fluoro-adenosine-5´-triphosphate and prevents deamination of the base as compared to ara-A.Clofarabine can be administered intravenously or given orally. Clofarabine enters cells via hENT1, hENT2, and hCNT2, where upon it is phosphorylated by deoxycytidine kinase to generate clofarabine-5´-monophosphate. The rate-limiting step in clofarabine metabolism is clofarabine-5´-diphosphosphate. Clofarabine-5´-triphosphate is the active-metabolite, and it inhibits ribonucleotide reductase, resulting in a decrease cellular dNTP concentrations, which promotes greater incorporation of clofarabine-5´-triphosphate during DNA synthesis.