MLA Domain 5 · Presentation
Dehydration
20 conditions in Finalist present this way. Work down the list and ask what would separate each one from the next — that discriminator is the exam question.
classic presentation · 1
recognised feature · 18
Seizures, reduced GCS, venous haemorrhagic infarction, pregnancy/postpartum
Salt-wasting adrenal crisis in a neonate → emergency (fluids, IV hydrocortisone, correct glucose/electrolytes)
Hypernatraemic dehydration (especially if thirst/access impaired — elderly, unconscious) → careful rehydration
Reduced consciousness, shock, K+ <3.5 before insulin, severe acidosis (pH <7.1) → HDU/ICU
Haemodynamic instability, hypothermia, high-output failure, secondary sepsis — admit
Severe metabolic acidosis/hypokalaemia/dehydration
A hot joint could be SEPTIC arthritis — aspirate to confirm crystals and exclude infection
Severe (>3.5) / symptomatic hypercalcaemia → emergency IV fluids + bisphosphonate
Severe dehydration, ketonuria, hyponatraemia/hypokalaemia → admit; consider Wernicke’s (give thiamine)
Profound dehydration/hypovolaemic shock, reduced GCS, very high osmolality; high thrombosis risk
C. difficile with toxic megacolon, ileus, shock, or rising lactate/WCC → severe disease, surgical input
Severe dehydration/shock; bloody diarrhoea (dysentery); EHEC O157 → HUS (no antibiotics); enteric fever (typhoid — trave
Severe dehydration, electrolyte derangement → resuscitate BEFORE surgery
Acute chest syndrome (hypoxia + new infiltrate) → emergency (oxygen, analgesia, antibiotics, transfusion/exchange)
Severe/rapid hyponatraemia with seizures/coma → hypertonic saline (specialist; avoid overcorrection → osmotic demyelinat
New pattern, red-flag features (see panel) → exclude secondary causes; medication-overuse if frequent analgesia
Perforation (sudden deterioration, free air, peritonitis) → emergency colectomy
Severe dehydration/hypokalaemia → arrhythmia, acute kidney injury
differential of the above · 1