Monitoring CBC and Platelet Count in Dengue Patients
Daily complete blood count monitoring is essential in dengue patients to track platelet counts and hematocrit levels, with particular attention to warning signs of severe dengue. 1
Monitoring Frequency
During Acute Phase (Days 1-6 of Illness)
- Monitor CBC and platelet count daily throughout the febrile and critical phases of dengue infection 1
- Daily platelet monitoring is particularly important as it helps identify patients at high risk of progressing to dengue shock syndrome (DSS) 2
- Serial daily platelet counts demonstrate better ability to discriminate patients who will develop DSS compared to single baseline measurements 2
Key Parameters to Track
Platelet Count:
- Platelet count ≤100 G/L during the first 3 days of illness is a significant prognostic indicator for severe dengue (OR = 2.2) 3
- Daily platelet trends are more valuable than isolated measurements for predicting complications 2
Hematocrit:
- Monitor hematocrit daily alongside platelet counts to detect plasma leakage 1
- Rising hematocrit with falling platelet count indicates warning signs of severe dengue 1
Additional Laboratory Parameters:
- During days 1-3: Focus on platelet count and serum albumin 3
- During days 4-6: Add monitoring of AST, ALT, and total bilirubin as prognostic indicators become more relevant 3
Clinical Context for Monitoring
Warning Signs Requiring Intensified Monitoring
Monitor more frequently if patients develop: 1
- Persistent vomiting
- Abdominal pain
- Lethargy or restlessness
- Mucosal bleeding
- Rising hematocrit with falling platelet count
Common Pitfalls to Avoid
- Do not rely solely on platelet count thresholds for transfusion decisions - prophylactic platelet transfusion in adult dengue patients with platelet count <20,000/mm³ without bleeding does not reduce bleeding risk and may actually slow platelet recovery 4
- Do not stop daily monitoring prematurely - continue daily CBC monitoring throughout the critical phase (typically days 3-7 of illness) even if initial values appear stable 1, 2
- Avoid monitoring hematocrit alone without platelet counts, as the combination provides better prognostic information 2
Duration of Monitoring
Continue daily monitoring until:
- Patient has been afebrile for at least 48 hours without antipyretics 1
- Platelet count shows consistent upward trend
- Hematocrit stabilizes
- Patient demonstrates hemodynamic stability for at least 24 hours 1
The evidence strongly supports daily monitoring rather than less frequent intervals, as dengue can progress rapidly during the critical phase (days 3-7), and daily platelet trends provide crucial prognostic information that single measurements cannot 2.