Table 7. Investigation of the delirious patient.

Targeted blood tests:	Serum electrolytes including Ca Serum Creatinine Serum glucose Full blood count
Urine analysis	Mid-stream urine for microscopy, culture and sensitivity
Search for occult infection	Wound swab Sputum for microscopy, culture and sensitivity Consider blood cultures
Targeted investigations as informed by the history and investigation	Electrocardiogram Post void residual bladder scan Chest X-ray Head CT
Further investigations to be considered if no cause found by above approach	Thyroid function and thyroid antibody tests Drug levels Toxicology screen Vitamin B12 and folate levels Syphilis serology Lumbar puncture Electroencephalography Vasculitic screen including ANA and ENAs

ANA: Antinuclear Antibody; ENA: Extractable Nuclear Antibodies