Being confused because of an acute medical condition is not “failing to cope!”, ‘Failure to cope’ usually means ‘failure on the part of the physician to make an adequate diagnosis’!
The acute confusional state is merely the symptom of the underlying condition. It is the Emergency physician’s job to diagnose the underlying condition.
Almost any medical illness, intoxication, or medication can cause delirium. Delirium is often multifactorial in etiology and each potential cause should be investigated. The cause of a geriatric delirium cannot always be identified. Failure to find a cause does not mean that delirium is not present, but that the cause has yet to be determined.
- Infections (Think PUS: pneumonia, urinary, skin/soft tissue)
- ACS (often does not present with chest pain – the elderly are more likely to complain of “weakness” dyspnea or as being “just not themselves”),
- Hepatic encephalopathy
- Fluid/electrolyte abnormalities (hypo-/hyper-natremia, hypoglycemia, hyper/hypocalcemia)
Infections are the most commonly encountered cause of geriatric delirium.
- Even seemingly non-psychotropic meds
- Accidental or intentional discontinuation of any medications (even seemingly non-psychotropic meds)
- Alcohol, sedative hypnotics. OTC
- Subdural hematoma – occult traumatic or spontaneous
- Seizures – nonconvulsive statis, postical
- Hypertensive encephalopathy
Mnemonics for Causes of Delirium
To reiterate: almost any medical illness, intoxication, or medication can cause delirium. Delirium is often multifactoral in aetiology and each potential cause should be investigated.
Below are some mnemonics for remembering causes of delirium.
I Watch Death Mnemonic
I- Infections – PUS, pneumonia, urinary, skin/soft tissue, CNS
W- Withdrawl – often unintentional, from alcohol, sedatives, barbiturates
A- Acute metabolic changes – altered pH, hypo/hyper Na+ Ca++, acute liver or renal failure
T- Trauma – brain injury, subdural hematoma
C- CNS pathology – post-ictal, stroke, tumour, brain mets
H- Hypoxia – CHF, anemia
D- Deficiencies – thiamine, niacin, B12 (e.g. chronic G and T alcoholics)
E- Endocrinopathies – hypo-/hyper-cortisol, hypoglycemia
A- Acute vascular – hypertensive encephalopathy, septic hypotension
T- Toxins and Drugs – especially anti-cholinergics, opioids, benzodiazepines
H- Heavy metals
D- Drugs, dehydration, detox, deficiencies, discomfort (pain)
E- Electrolytes, elimination abnormalities, environment
L- Lungs (hypoxia), liver, lack of sleep, long ED stay
I- Infection, iatrogenic events, infarction (cardiac, cerebral)
R- Restraints, restricted movement/mobility, renal failure
I- Injury, impaired sensory input, intoxication
U- UTI, unfamiliar environment
M- Metabolic abnormalities (glucose, thyroid), metastasis (brain), medications