Day 5 dengue with narrowing pulse pressure in a hospital without ICU
A 27-year-old previously healthy man is admitted to a secondary hospital in a dengue-endemic district on day 5 of fever. His temperature settled 14 hours ago, but he now has colicky abdominal pain and has vomited twice. Lying BP is 100/78 mmHg, sitting BP 88/70 mmHg, pulse 112/min and regular, with cool peripheries and capillary refill of 3 seconds. Haematocrit is 48%; a clinic sample taken on day 2 was 41%. Platelets are 28,000/µL, white cells 3,200/µL and ALT 180 U/L. Urine output has been 0.5 mL/kg/h over the last 4 hours. There is no bleeding, but bedside ultrasound shows gallbladder wall thickening and minimal ascites. The hospital has no intensive care unit, the nearest tertiary ICU is 2.5 hours away by road, and ambulance transfer is only arranged during daylight.
1. What phase of dengue is he in, and how do the vital signs and haematocrit fit together physiologically?
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He is in the critical (plasma leakage) phase, which classically spans the 24–48 hours around defervescence - here, fever settled 14 hours ago.
The haemoconcentration is the key objective marker: haematocrit has risen from a documented baseline of 41% to 48%, a rise of about 17%, which in a febrile patient with a settled temperature indicates plasma leakage rather than dehydration. The vital signs describe compensated shock: systolic pressure has fallen and the pulse pressure has narrowed to 22 mmHg (100/78), with tachycardia, cool peripheries and delayed capillary refill. Narrow pulse pressure reflects reduced stroke volume plus increased peripheral resistance; diastolic pressure is relatively preserved while systolic falls early. The postural drop of 12 mmHg systolic on sitting is an additional warning sign.
Thrombocytopenia of 28,000/µL is expected in the critical phase but does not by itself dictate fluid management; the decision is driven by perfusion and leakage, not the platelet count. The raised ALT indicates hepatic involvement and is a warning sign. Urine output of 0.5 mL/kg/h sits at the lower limit and, with the ultrasound findings, supports significant leakage. Overall: dengue with warning signs and compensated shock, requiring immediate crystalloid and hourly reassessment, not watchful waiting.
2. Set out your immediate fluid plan, including volumes, reassessment endpoints, and the error you must avoid over the next 24 hours.
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Give a crystalloid bolus of 0.9% sodium chloride at 10 mL/kg over 30–60 minutes, then reassess immediately. The volume is deliberately modest because the leak is transient and the therapeutic window is narrow: too little fluid permits progression to decompensated shock and organ hypoperfusion, while too much produces pleural effusions, ascites and pulmonary oedema that can persist after the leak resolves.
Reassess after each bolus using: pulse rate and volume, pulse pressure, capillary refill, conscious level, urine output (target at least 0.5–1 mL/kg/h), and haematocrit. A falling haematocrit with stable or improving perfusion signals recovery and dilution; a rising haematocrit with persistent tachycardia means ongoing leakage and justifies a further 10 mL/kg. Stop escalating once perfusion is restored.
The error to avoid is continuing high-rate fluid after shock has resolved, or repeatedly bolusing on a fixed schedule without clinical reassessment. Once perfusion and urine output are adequate, taper to approximately 2–3 mL/kg/h and then reduce further over 24–48 hours as the critical phase ends. If he develops respiratory distress, a fall in saturation, basal crepitations, or a rapidly falling haematocrit without clinical improvement, consider fluid overload or occult bleeding and stop the infusion while you reassess.
3. How do you decide whether to transfer him, and what must be arranged before and during the journey?
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Transfer is a time-critical decision here because the hospital cannot provide vasopressors, invasive monitoring or blood products, and the road journey is only feasible in daylight. Use explicit reassessment triggers rather than waiting for deterioration.
Transfer if any of the following occur after one or two boluses: persistent tachycardia with a narrow pulse pressure or unrecordable diastolic pressure; urine output remaining below 0.5 mL/kg/h; rising haematocrit with clinical deterioration; significant bleeding or a falling haematocrit with instability; altered consciousness or seizure; clinical suspicion of myocarditis or hepatic or renal impairment; or inability to check haematocrit and vital signs at least hourly. He already has warning signs and borderline output, so he is close to that threshold - document a clear reassessment time, and if he has not clearly improved, move him while daylight allows rather than waiting for the next morning.
Before departure: secure two intravenous lines, calculate the current infusion rate on a written chart, attach a monitoring sheet with hourly observations, and speak directly to the receiving ICU so a bed is accepted. Send a trained escort with oxygen, suction, resuscitation drugs and a manual blood pressure cuff, because monitors may fail. Continue the tapering fluid rate rather than a rapid infusion during transport, since unintentional over-resuscitation in transit is a common and avoidable harm. Send the clinic and hospital haematocrit values so the receiving team can interpret any further rise.