An 83-year-old man was admitted to hospital after being unable to cope alone at home with an episode of diarrhoea and vomiting. His past medical history included hypertension, bilateral total hip replacements, and early dementia. He did not smoke but drank 30–40 units of alcohol each week. His medication on admission was amlodipine and donepezil.
He improved with 48 hours of intravenous fluids, at which point the cannula was removed because pus was noticed at the insertion site. His discharge home was delayed because he became increasingly confused.
His temperature was 35.9°C, heart rate 95 beats per minute, blood pressure 105/60 mmHg (having been previously 150/80 mmHg), and respiratory rate 22 breaths per minute. His feet were cold with pitting
oedema around his ankles.
Investigations:
Hb 113 g/L (130–180)
WBC 3.8 × 109/L (4–11)
platelets 98 × 109/L (150–400)
INR 1.6 (<1.4)
serum sodium 134 mmol/L (137–144)
serum potassium 3.2 mmol/L (3.5–4.9)
serum urea 10.1 mmol/L (2.5–7.0)
serum creatinine 89 μmol/L (60–110)
serum total bilirubin 29 μmol/L (1–22)
plasma glucose 8.0 mmol/L
Which of the following is the most likely cause of his acute confusional state?
0%Alcohol withdrawal
0%Electrolyte disturbance
0%Sepsis
0%Hepatic encephalopathy
Sepsis may present insidiously, especially in the elderly and immunocompromised. A wide range of symptoms and signs may be associated with infection (including those traditionally thought of as markers of sepsis, such as a high white cell count or C reactive protein); for example, altered mental state, fluid retention, ileus, tachypnoea, and poor peripheral perfusion. In this case a probable source of infection (the intravenous cannula) can be identified. In association with this, SIRS is present (tachycardia and low white cell count) as well as thrombocytopenia, altered mental status, hyperglycaemia in the absence of diabetes, and coagulopathy; hence, sepsis is the most likely diagnosis. Blood cultures should be drawn and broad-spectrum antibiotics started to cover likely pathogens (staphylococcus and streptococcus in this situation). None of the other options can explain the full clinical picture although they may have a contribution to his confusion (especially alcohol withdrawal).