Intensive care unit (ICU)

Assessment Agitation and sedation Give some causes of acute confusion in the post-operative patient Pain (anxiety and disorientation) : all of these can commonly occur in critically ill patients Sepsis : systemic infection, or localised to chest, urinary tract, wound, intra-abdominal, intrathoracic, intracranial collection Glycaemic disturbances : this occurs most commonly with hypoglycaemia, but can occur in hyperglycaemia, e.g. ketoacidosis Metabolic : electrolyte disturbances can precipitate agitation, most commonly hypo- or hypernatraemia Respiratory : a compromise in respiratory function can lead to hypoxaemia and hypercarbia. Usual precipitating causes, apart from a chest infection, include acute pulmonary oedema, pneumothorax, pulmonary embolism, sputum retention and subsequent atelectasis Cardiovascular : low cardiac output state and hypotension from any cause, e.g. bleeding, myocardial infarction, arrhythmia leading to reduced cerebral perfusion Renal : acute kidney injury and hepatic failure can cause the accumulation of encephalopathic toxins to develop, e.g. uraemia. Urinary retention in the elderly can be a causative factor Fluid imbalance : both dehydration and water overload can exacerbate the hyponatraemia due to the fluid retention from the stress response to surgery Drugs : e.g. opiate analgesia, excess sedative drugs, anticholinergics Which investigations should you perform? Following a full history and examination investigations include Bedside investigations Boehringer Mannheim (BM) : this rapidly assesses if the capillary glucose is low and this provides a value 7% higher than plasma values Arterial blood gas (ABG) analysis : this determines the base excess and respiratory function, e.g. if hypoxia or hypercarbia is present Electrocardiograph (ECG) : for arrhythmias or myocardial infarction that can reduce the cerebral perfusion Non-bedside investigations Haematology : the full blood count (FBC) needs to be assessed for presence of infection, e.g. leucocytosis, neutrophilia and anaemia Biochemistry : this includes serum electrolytes and base renal function (U&Es), e.g. sodium, potassium, calcium, phosphate and magnesium to correct electrolyte disturbances, and urea and creatinine to help guide fluid therapy. The inclusion of liver function tests (LFTs) helps to determine hypoalbuminaemia Microbiology (sepsis screen) : blood cultures, wound swabs, urine and sputum cultures to detect the presence of occult infection Radiology : such as a chest radiograph to detect a chest Infection What is the purpose of sedation in the critical care setting?